ROČNÍK/VOL. LXV
ROK/YEAR 2012
7
METALLURGIC AL
JOURNAL
O D B O R N Ý Č A S O P I S P R O M E TA L U R G I I A M AT E R I Á L O V É I N Ž E N Ý R S T V Í
PROFESSIONAL PERIODICAL FOR METALLURGY AND MATERIAL ENGINEERING
mimořádné vydání
special edition
W W W. H U T N I C K E L I S T Y. C Z
ISSN 0018-8069
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Vydavatel
OCELOT s.r.o.
Pohraniční 693/31
706 02 Ostrava-Vítkovice
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OCELOT s.r.o.
Redakce časopisu Hutnické listy
areál VŠB – TU Ostrava, A 534
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www.hutnickelisty.cz
www.metallurgicaljournal.eu
Vedoucí redaktor
Ing. Jan Počta, CSc.
 596995156
e-mail: [email protected]
[email protected]
Redaktorka
Jaroslava Pindorová
e-mail: [email protected]
Redakční rada
Předseda:
Prof.Ing. Ľudovít Dobrovský, CSc., Dr.h.c.,
VŠB-TU Ostrava
Členové:
Ing. Michal Baštinský, EVRAZ VÍTKOVICE
STEEL, a.s.
Ing. Karol Hala, U.S. Steel Košice, s.r.o.
Prof. dr. hab. inž. Leszek Blacha,
Politechnika Šląska
Prof. dr. hab. inž. Henryk Dyja, Politechnika
Częstochowska
Prof. Ing. Vojtěch Hrubý, CSc. Univerzita
obrany
Ing. Henryk Huczala, TŘINECKÉ
ŽELEZÁRNY, a.s.
Prof. Ing. František Kavička, CSc., VUT
v Brně
Ing. Ludvík Martínek, Ph.D., ŽĎAS, a.s.
Prof. Ing. Karel Matocha, CSc.,
MATERIÁLOVÝ A METALURGICKÝ
VÝZKUM s.r.o.
Ing. Radim Pachlopník, ArcelorMittal
Ostrava, a.s.
Prof. Ing. Ľudovít Pariľák, CSc., ŽP VVC
s.r.o.
Ing. Jiří Petržela, Ph.D., VÍTKOVICE
HEAVY MACHINERY, a.s.
Ing. Jaroslav Pindor, Ph.D., MATERIÁLOVÝ
A METALURGICKÝ VÝZKUM s.r.o.
Ing. Vladimír Toman, Hutnictví železa, a.s.
Prof. Ing. Karel Tomášek, CSc., TU
v Košiciach
Grafika titulní strany a redakce
Miroslav Juřica,
e-mail [email protected]
Tisk
T-print s.r.o., Průmyslová 1003, 739 65
Třinec
Registrační číslo
MK ČR E 18087
Mezinárodní standardní číslo
ISSN 0018-8069
Odborný časopis pro metalurgii a materiálové inženýrství
.
Obsah
prof. Ing. Ján Vavro, PhD.
úvodní slovo
5
materiálové inženýrství
doc. Ing. Jan Krmela, PhD.
Zvláštnosti specifických kompozitů s elastomerovou matricí a ocelokordovou
výztuží při zatěžování tahem
Ing. Vladimíra Krmelová, PhD., Ing. Katarína Kostelanská, PhD., doc. Ing. Jan
Krmela, PhD., doc. Ing. Iva Sroková, PhD.
Vybrané mechanické a fotochemické vlastnosti zmesí HEC/HEC-Cin
doc. Ing. Milan Olšovský, PhD., Ing. Michal Dubovský
Vplyv prídavku biopalív na gumové tesnenia leteckých motorov
doc. Ing. Iva Sroková, CSc., Ing. Jaroslava Janíčková, Ing. Ladislav Janek, RNDr.
Vlasta Sasinková, Mgr. Agáta Dujavová-Laurenčíková, PhD.
Hydrofobizovaný KMŠ a jeho využitie v gumárenskej zmesi
doc. RNDr. Ján Bezecný, CSc., Ing. Robert Vavrík
Krehnutie malých oceľových súčiastok pri ich tepelnom spracovaní
v kontinuálnych linkách
doc. Ing. Iva Sroková, CSc., Ing. Ladislav Janek, Ing. Jaroslava Janíčková, Ing.
Mária Chromčíková, RNDr. Vlasta Sasinková
Polymérne zmesi na báze styrén-butadiénoveho kaučuku
doc. Mgr. Ivan Kopal, PhD., Ing. Karol Kováč, Ing. Mária Bačíková, RNDr. Peter
Hybler, PhD., Ing. Marko Fülöp, CSc., Ing. Vladimír Rusnák
Vplyv ožiarenia lúčom urýchlených elektrónov na dynamické mechanické
vlastnosti nevulkanizovanej styrén butadiénovej gumárenskej zmesi
doc. Ing. Pavol Lizák, PhD., Ing. Jaroslav Ligas, PhD., Ing. Jela Legerská, PhD.
Závislosť medzi geometrickými vlastnosťami vlákien a priadzí
prof. Ing. Darina Ondrušová, PhD., Ing. Slavomíra Domčeková, Ing. Lenka
Špániková, Ing. Mária Kopcová, Ing. Ivan Cehlárik, Ing. Janka Jurčiová, PhD.
Porovnanie vplyvu plnív na báze siliky na spracovateľnosť gumárenských
zmesí
prof. Ing. Darina Ondrušová, PhD., Ing. Lenka Špániková, Ing. Mária Kopcová, Ing.
Slavomíra Domčeková, Ing. Michaela Ďurčeková, prof. Ing. Eugen Jóna, Dr.Sc.
Skúmanie vplyvu nových nanoplnív na báze klinoptilolitu na vlastnosti
gumárenských zmesí
Ing. Vladimíra Krmelová, PhD., Ing. Katarína Kostelanská, PhD., doc. Ing. Iva
Sroková, PhD., doc. Ing. Milan Olšovský, PhD., RNDr. Vlasta Sasinková
Príprava, charakterizácia a termické vlastnosti cinamátov HEC
Ing. Petra Skalková, PhD., Ing. Jaroslava Michálková
Vplyv povrchovo aktívnej látky na mechanické vlastnosti polymérnych zmesí
doc. RNDr. Mariana Pajtášová, PhD., Ing. Jana Paliesková, Ing. Andrea
Feriancová, Ing. Zuzana Jankurová, prof. Ing. Eugen Jóna, DrSc.
Vplyv nearomatických olejov na vlastnosti zimných behúňových zmesí
doc. RNDr. Mariana Pajtášová, PhD., Ing. Zuzana Jankurová, prof. Ing. Eugen
Jóna, DrSc., Ing. Katarína Holcová, Ing. Jana Paliesková, Ing. Mária Kopcová
Vplyv rôznych plnív na fyzikálno–mechanické vlastnosti modelových
gumárenských zmesí
doc. RNDr. Mariana Pajtášová, PhD., Ing. Andrea Feriancová, Ing. Jana
Paliesková, prof. Ing. Eugen Jóna, DrSc.
Termická a Rtg analýza kaolínu interkalovaného dimetylsulfoxidom
a iónmi CuII
doc. RNDr. Mariana Pajtášová, PhD., Ing. Katarína Holcová, prof. Ing. Martin
Jambrich, DrSc., Ing. Zuzana Jankurová
Vláknité materiály na báze polypropylénových a iných vlákien
RNDr. Viera Mazíková, PhD., doc. Ing. Milan Olšovský, PhD.
Štúdium termostabilných esterov z O-(karboxymetylškrobu)
Ing. Petra Skalková, PhD., Ing. Jana Pagáčová, PhD., Ing. Martin Březina, CSc.,
Ing. Michal Kapusňák
Metódy starnutia a charakterizácia LDPE/CMS zmesí
prof. Ing. Eugen Jóna, DrSc., Ing. Simona Lendvayová, Ing. Stanislava
Uherková, doc. RNDr. Mariana Pajtášová, PhD., prof. Ing. Darina Ondrušová,
PhD., Ing. Jozef Kraxner, PhD.
Termická stabilita skiel systému Li2O - 2SiO2
7
10
13
16
19
22
25
28
31
34
37
40
43
46
49
52
55
58
61
neželezné kovy a slitiny
doc. Ing. Marta Kianicová, PhD., Ing. Dana Bakošová, PhD.
Štúdium zliatín medi použitím atómovej silovej mikroskopie
63
ekologie, recyklace, druhotné zpracování materiálu
doc. Ing. Pavol Lizák, PhD.
Aplikácia recyklovaných textílií v odevnom dizajne
prof. Ing. Eugen Jóna, DrSc., Ing. Róbert Janík, PhD., prof. Ing. Darina Ondrušová,
PhD., doc. RNDr. Mariana Pajtášová, PhD., Ing. Martina Loduhová, Ing. Zuzana
Harmatová
Odstraňovanie toxických derivátov fenolu z vodných roztokov použitím
Co-montmorillonitu
prof. Ing. Darina Ondrušová, PhD., Ing. Michaela Ďurčeková, Ing. Lenka Špániková,
Ing. Slavomíra Domčeková, Ing. Martina Čechová
Odstraňovanie železa z vodných roztokov pomocou modifikovaného zeolitu
66
69
72
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Hlavní články v časopisu jsou uváděny
v českém, slovenském nebo anglickém
jazyce.
Časopis vychází 6x ročně. Cena
jednotlivého čísla 200,-- Kč. K ceně se
připočítává DPH. Roční předplatné
základní 1190,- Kč, studentské 20 %
sleva proti potvrzení o studiu.
Předplatné se zvyšuje o poštovné
vycházející z dodávek každému
odběrateli. Předplatné se automaticky
prodlužuje na další období, pokud je
odběratel jeden měsíc před uplynutím
abonentního období písemně nezruší.
Objednávky na předplatné přijímá
redakce. Informace o podmínkách
publikace, inzerce a reklamy podává
redakce.
Za původnost příspěvků, jejich věcnou
a jazykovou správnost odpovídají
autoři. Podklady k tisku redakce
přijímá
v elektronické
podobě.
Recenzní posudky jsou uloženy
v redakci. Žádná část publikovaného
čísla nesmí být reprodukována,
kopírována nebo elektronicky šířena
bez písemného souhlasu vydavatele.
© OCELOT s.r.o., 2012
ISSN 0018-8069
Odborný časopis pro metalurgii a materiálové inženýrství
.
koroze
doc. Ing. Marta Kianicová, PhD., Ing. Ján Kafrík, Ing. Jaroslav Trník,
Ing. Ondřej Dvořáček
Zmeny mikroštruktúry po vysokoteplotnej korózii vybraných difúznych
povlakov
75
povrchová úprava
doc. Ing. Marta Kianicová, PhD., Ing. Ján Kafrík, Ing. Jaroslav Trník, Ing. Dana
Bakošová PhD., Ing. Ondřej Dvořáček
Vplyv vytrvalostnej skúšky na mikroštruktúrne charakteristiky CVD povlaku
78
zkušebnictví, měřictví, laboratorní metody
81
doc. Ing. Jan Krmela, PhD., Ing. Michal Pastorek
Stanovení radiální tuhosti pneumatiky z experimentů na statickém zkušebním
zařízení nazývaném statický adhezor
doc. RNDr. Ján Bezecný, CSc., Ing. Ján Mičic
Modelovanie krehkého porušovania tenkostenných oceľových súčiastok
doc. RNDr. Ján Bezecný, CSc., Ing. Annamária Petráňová
Modifikácia zariadenia EDDYSCAN na presné meranie
doc. Ing. Pavol Lizák, PhD., Ing. Jaroslav Ligas, PhD.
Meranie hmotnej nerovnomernosti priadzí
85
88
91
tepelná technika
94
doc. Mgr. Ivan Kopal, PhD., Ing. Karol Kováč, Ing. Richard Puchký
Odhad tepelnej kapacity použitím parametrického fitovania kriviek chladnutia
doc. Mgr. Ivan Kopal, PhD., Ing. Karol Kováč, Ing. Silvia Uríčová, Ing. Mária
Bačíková
Štúdium termofyzikálnych parametrov autopoťahov rôznej hrúbky
doc. Ing. Pavol Lizák, PhD., Ing. Jela Legerská, PhD., Ing. Jaroslav Ligas, PhD.
Vplyv elektrických vlastností na tepelno-izolačné vlastnosti tkanín
98
101
počítačová simulace, výpočetní metody
doc. Ing. Jan Krmela, PhD., Ing. Jozefína Drdáková, Ing. Ivan Kováč, Ing. Peter
Vido, Ing. Michal Pastorek, Ing. Monika Struharňanská
Stanovenie Mooney-Rivlinových parametrov nánosových zmesí oceľokordov
pre vstupy do MKP výpočtových modelov pneumatík
prof. Ing, Ján Vavro, PhD., Ing. Ján Vavro, PhD., jr., Ing. Alena Vavrová, PhD., Ing.
Petra Kováčiková, Ing. Robert Vanc
Dynamická analýza ovíjacieho mechanizmu pri výrobe osobných
a nákladných surových autoplášťov
prof. Ing, Ján Vavro, PhD., Ing. Ján Vavro, PhD., jr., Ing. Alena Vavrová, PhD., Ing.
Petra Kováčiková, Ing. Robert Vanc
Numerická analýza vlastných frekvencií tvárnej liatiny s guľôčkovým tvarom
grafitu a sivej liatiny s lupienkovým tvarom grafitu
doc. RNDr. Ladislav Matejíčka, CSc.
Niekoľko poznámok na Carlemanovu nerovnosť
104
doc. RNDr. Ladislav Matejíčka, CSc
Poznámka k jednému otvorenému problému nekonečných rad
121
107
110
115
řízení jakosti
Časopis zařazen Radou vlády ČR pro
výzkum a vývoj do seznamu recenzovaných
neimpaktovaných
periodik
vydávaných
v ČR.
prof. Ing, Ján Vavro, PhD., Ing. Ján Vavro, PhD., jr., Ing. Alena Vavrová, PhD., Ing.
Petra Kováčiková
Experimentálna a teoretická analýza vád pneumatík nákladných vozidiel pri
dynamickom zaťažení
Hlavní články jsou evidovány v mezinárodní
databázi
METADEX
a
ILLUSTRATA
TECHNOLOGY, obě spravované firmou
ProQuest, USA.
Abstrakty hlavních článků jsou evidovány
v české, slovenské a anglické verzi na
webových stránkách Hutnických listů.
Články v tomto vydání jsou vytištěny ve stavu dodání od autorů
a redakce neprováděla jazykovou korekturu.
Inzerenti a objednatelé reklamy:
● Fakulta priemyselných technológií v Púchove, TUAD v Trenčíne
123
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Odborný časopis pro metalurgii a materiálové inženýrství
.
C o n t e n t
Material Engineering
Krmela, J.
Traits of Specific Composites with Elastomer Matrix and Steel-cord Reinforcement during Tensile Load
7
Krmelová, V. - Kostelanská, K. - Krmela, J. - Sroková, I.
Selected Mechanical and Photosensitive Properties of HEC/HEC-Cin Blends
Olšovský, M. – Dubovský, M.
The Influence of Addition of the Biofuels on the Rubber Seals in Aero Engines
10
Sroková, I. - Janíčková, J. - Janek, L. - Sasinková, V. - Dujavová-Laurenčíková, A.
Hydrophobic CMS and its Usage in the Rubber Blend
16
Bezecný, J. – Vavrík, R.
The Embrittlement of Small Steel Components which are Heat Treated in Continuous Links
19
Sroková, I. - Janek, L. - Janíčková,J. - Chromčíková, M. – Sasinková, V.
Polymer Blends Based on Styrene-Butadiene Rubber
22
Kopal, I. - Kováč, K. - Bačíková, M. - Hybler, P. - Fülöp, M. – Rusnák, V.
Influence of Electron Beam Irradiation on the Dynamic Mechanical Properties of Non-vulcanized Styrene-butadiene Rubber Blend
25
Lizák, P. - Ligas,J. - Legerská, J.
Relationship between the Geometrical Properties of the Fibers and Yarns
28
Ondrušová, D. - Domčeková, S. - Špániková, L. - Kopcová, M. - Cehlárik, I. - Jurčiová, J.
Comparison of Influence of Silica Fillers on the Rubber Compounds Processing
31
Ondrušová, D - Špániková, L. - Kopcová, M. - Domčeková, S. - Ďurčeková, M. - Jóna, E.
Study of the Impact of New Nanofillers Based on Clinoptilolite on the Properties of Rubber Compounds
34
Krmelová, V. - Kostelanská, K. - Sroková, I. - Olšovský, M. – Sasinková, V.
Preparation, Characterization and Thermal Properties of Hydroxyethylcellulose Cinnamates
37
Skalková, P. – Michálková, J.
Effect of Surfactant on Mechanical Properties of Polymer Blends
40
Pajtášová, M. - Paliesková, J. - Feriancová, A. - Jankurová, Z. - Jóna, E.
The Influence of Non-aromatic Oils on the Properties of Winter Tread Compounds
43
Pajtášová, M. - Jankurová, Z. - Jóna, E. - Holcová, K. - Paliesková, J. – Kopcová, M.
Influence of Various Fillers on Physical and Mechanical Properties of Model Rubber Compounds
46
Pajtášová, M. - Feriancová, A. - Paliesková, J. - Jóna, E.
Thermal and XRD Analysis of Intercalation Process of Kaoline with Dimetyl Sulfoxide and CuII Ions
49
Pajtášová, M. - Holcová, K. - Jambrich, M. – Jankurová, Z.
Fibrous Materials Based on Polypropylene and Other Fibers
52
Mazíková, V. - Olšovský, M.
Investigation of Thermostable Esters from O-(carboxymethylstarch)
55
Skalková, P. - Pagáčová, J. - Březina, M. – Kapusňák, M.
Methods of Ageing and Characterization of LDPE/CMS Blends
58
Jóna, E. - Lendvayová, S. - Uherková, S. - Pajtášová, M. - Ondrušová,D. - Kraxner, J.
Thermal Stability of Glasses of the Li2O - 2SiO2 System
61
13
Non-ferrous Metals and Alloys
Kianicová, M. - Bakošová, D.
Study of Copper Alloys by Atomic Force Microscopy
63
Environmental Protection, Recycling, Secondary Material Processing
Lizák, P.
Application of Textile Recycling in the Clothing Design
Jóna, E. - Janík, R. - Ondrušová, D. - Pajtášová, M. - Loduhová, M. – Harmatová, Z.
Removal of Toxic Phenol Derivatives from Water Solutions by Using Co-montmorillonite
66
Ondrušová, D.- Ďurčeková, M. - Špániková, L. - Domčeková, s. – Čechová, M.
Removal of Iron from Aqueous Solutions Using a Modified Zeolite
72
69
Corrosion
Kianicová, M. - Kafrík, J. - Trník, J. – Dvořáček, O.
Changes in Microstructure of Selected Diffusion Coatings after Hot Corrosion
75
Surface Treatment
Kianicová, M. - Kafrík,J. - Trník, J. – Bakošová, D. – Dvořáček, O.
Influence of Endurance Time Test on Microstructure Characteristics of CVD Coating
78
Testing, Measurement, Laboratory Methods
Krmela, J. – Pastorek, M.
Determination of Radial Stiffness of Tire from Experiments on the Static Test Device Called Static Adhesor
Bezecný, J. – Mičic, J.
Simulation of Brittle Rupture of Thin-walled Steel Components
Bezecný, J. – Petráňová, A.
Modification of Equipment EDYSCAN for Accurate Measurement
81
85
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Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Odborný časopis pro metalurgii a materiálové inženýrství
.
Lizák, P. - Ligas, J.
Coefficient of Variation Measurements of Yarns
91
Thermal Engineering, Reheating Furnaces, Refractory Material
94
Kopal, I. - Kováč, K. – Puchký, R.
Estimation of Specific Heat by Parametrical Fitting of Cooling Curves
Kopal, I. - Kováč, K. - Uríčová,S. – Bačíková, M.
The Thermophysical Parameters Study of Car Seat Covers with Different Thickness
Lizák, P. - Legerská, J. - Ligas, J.
Influence of Electrical Properties on the Thermal-insulation Properties of the Textile Fabrics
98
101
Computer Simulation, Computing Methods
Krmela, J. - Drdáková, J. - Kováč, I. - Vido, P. - Pastorek, M. – Struharňanská, M.
Determination of Mooney-Rivlin Parameters of Rubber Used for Rubberizing of Steel cords as an Input for FEA Models of Tire
Vavro, J. - Vavro, J. jr. - Vavrová, A. - Kováčiková, P. – Vanc, R.
Dynamic Analysis of Winding Mechanism during the Manufacturing Process of Passenger and Freight Raw Car Tyres
Vavro, J. - Vavro, J., jr. - Vavrová, A. - Kováčiková, P. – Vanc, R.
Numeric Analysis of the Eigenfrequencies of the Ductile Cast Iron with the Spheroidal Shape of Graphite and Grey Cast Iron with
the Lamellar Shape of Graphite
Matejíčka, L.
Some Remarks on Carleman's Inequality
Matejíčka, L.
Note On Open Problem of Infinite Series
104
107
110
115
121
Duality Management
Vavro, J. - Vavro, J. jr. - Vavrová, A. - Kováčiková, P.
The Experimental and Theoretical Analysis of the Defects in Tyres for Freight Vehicles at the Dynamic Loading
123
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Odborný časopis pro metalurgii a materiálové inženýrství
ISSN 0018-8069

PROFIL FAKULTY PRIEMYSELNÝCH TECHNOLÓGIÍ SO SÍDLOM V PÚCHOVE
Fakulta priemyselných technológií so sídlom v Púchove (FPT)
(www.fpt.tnuni.sk) svojím zameraním predstavuje unikát v rámci
Slovenskej republiky vo výchove odborníkov v oblasti kovových, ale
najmä nekovových materiálov, gumy, silikátových materiálov a
textilu. FPT po 16 rokoch svojej existencie plní zadané poslanie ako
vysokoškolská inštitúcia vo všetkých oblastiach. Má stabilné
postavenie v rámci vysokého školstva na Slovensku a dosiahla aj
významný medzinárodný kredit. Fakulta výborne obstála v procese
Komplexnej akreditácie, v ktorej obhájila akreditácie vo všetkých
troch stupňoch vysokoškolského štúdia (Bc., Ing., PhD.) a naviac, ako
jediná z fakúlt Trenčianskej univerzity, má právo uskutočňovať
habilitačné konanie a konanie na vymenovanie profesorov v študijnom
odbore 5.2.26 materiály.
Za 16 rokov existencie sa na FPT vybudovala kvalitná vedeckovýskumná základňa v oblasti experimentálnej diagnostiky materiálov.
Rovnako neodmysliteľnou súčasťou výskumu je vybudovanie
laboratórií pre numerickú analýzu a simuláciu technologických
procesov pomocou komerčných softvérov ako sú Proinžinier, Marc, Cosmos, Adams, Adina, Mathematica, Matlab,
Abaccus, Nastran a ďalšie. Materiálový výskum sa dnes zameriava aj na oblasť kompozitných materiálov.
Pracovníci FPT sú aktívnymi riešiteľmi grantových projektov (VEGA, KEGA, AV, APVV) a úloh aplikovaného
výskumu v rámci spolupráce s priemyslom. Do riešenia jednotlivých vedeckých a výskumných úloh sa zapájajú aj
študenti doktorandského, inžinierskeho i bakalárskeho štúdia, a to najmä formou záverečných bakalárskych,
diplomových a dizertačných prác.
Prioritou FPT od jej založenia je úzka spolupráca s priemyselnou praxou, ktorú fakulta neustále rozvíja. Témy
takmer všetkých záverečných bakalárskych, diplomových a dizertačných prác sa zadávajú na základe požiadaviek
z podnikateľskej praxe. Vedúcimi, resp. konzultantmi záverečných prác sú aj viacerí odborníci z výrobných
podnikov a výskumných ústavov, čím sa vytvára záruka praktickej realizácie výsledkov absolventských prác
a vznikajú výborne predpoklady uplatnenia absolventov fakulty v podnikateľskej sfére. V hodnotení najväčšieho
záujmu podnikateľskej sféry o absolventov fakúlt za minulý rok, sa naša fakulta umiestnila na významnom siedmom
mieste, zo všetkých fakúlt Slovenska.
V súčasnosti má FPT cca 500 študentov vo všetkých formách štúdia, z toho je 40 doktorandov. V štruktúre fakulty
sú štyri katedry:
Katedra materiálového inžinierstva so zameraním vedecko-výskumnej činnosti na:
Oblasť so zameraním na kovy a ich zliatiny, predovšetkým na materiály určené pre prácu v agresívnom prostredí
vysokých teplôt a koróznych činiteľov, ako aj na ich degradáciu a testovanie pre určenie ich životnosti za
stanovených podmienok. Testovanými materiálmi sú napríklad komponenty leteckých turbín, ktoré sú odlievané z
niklových superzliatin a pokryté aluminidnými povlakmi na zvýšenie odolnosti voči koróznym účinkom plynov,
prúdiacich zo spaľovacej komory. Oblasť so zameraním na grafitické liatiny a liatiny s vermikulárnym grafitom
(legovanými a nelegovanými), korózivzdornú austenickú oceľ, titánové zliatiny využívané pre ľudský organizmus,
povrchové úpravy kovových a nekovových materiálov, povlakované a nepovlakované vrstvy, skúšky opotrebenia
(korózne, kavitačné a abrazívne metódy) na kovových materiáloch, zliatinách neželezných kovoch a keramike,
materiálové vstupy pre výpočtové modelovanie, degradačné procesy konštrukčných prvkov, hodnotenie
mikroštruktúr a lomových plôch z pozície medzných stavov, deštrukčné a nedeštrukčné skúšky materiálov.
Materiálové inžinierstvo so zameraním na oblasť fyzikálnej metalurgie a medzných stavov materiálov so zameraním
na vzájomný súvis mikroštrukturálnych, fraktografických a mechanických vlastností kovových materiálov v
závislosti od aplikovanej technológie výroby strojných súčastí (optimalizácia technológií tepelného spracovania,
výskum navodíkovania ocelí, materiálové expertízy havarijných stavov).


Odborný časopis pro metalurgii a materiálové inženýrství
ISSN 0018-8069
Hutnické listy č.7/2012, roč. LXV

Katedra materiálových technológií a environmentu so zameraním vedecko-výskumnej činnosti na:
Základný ako aj na aplikovaný výskum prioritne nekovových materiálov, kompozitných materiálov
a nanomateriálov. Vedecko-výskumná činnosť na katedre materiálových technológií a environmentu vychádza už
dlhodobo z jej úzkej spolupráce s priemyselnou praxou. Hlavnými oblasťami výskumu na katerde sú:
Oblasť makromolekulových materiálov: vývoj a modifikácia gumárenských zmesí; nové postupy prípravy
predpolymérov, kvapalných kaučukov a elastomérov na netradičnej surovinovej báze a ich aplikácia v praxi; vývoj
chemických a fyzikálnych modifikácií prírodných a syntetických polymérov; výskum textilných vlákien. Oblasť
anorganických materiálov: skúmanie vzťahov medzi vlastnosťami anorganických materiálov a ich zložením; vývoj
nových druhov skiel; výskum v oblasti sol-gel metód (vrstvy, kompozity, katalýza); modifikácia zloženia
anorganických materiálov.
Oblasť environmentálneho inžinierstva: ekologizácia výroby polymérnych materiálov; skúmanie
ekologizácie výroby anorganických materiálov; skúmanie vplyvov priemyselných technológií na zložky
prostredia; výskum v oblasti využitia prírodných materiálov na báze silikátov na detoxikáciu zložiek
prostredia, biodegradácia materiálov, vývoj progresívnych materiálov pre likvidáciu škodlivín zo
prostredia.
možností
životného
životného
životného
Katedra numerických metód a výpočtového modelovania so zameraním vedecko-výskumnej
činnosti na:
Numerickú analýzu a simuláciu technologických procesov, výpočtového modelovania s využitím komerčných
softvérov ako sú ADINA, COSMOS, NASTRAN, ADAMS a pod.
Kompozitné materiály, elastoméry z pohľadu experimentov – mechanických skúšok a MKP výpočtov,
degradačných procesov s orientáciou na autoplášte osobných a nákladných automobilov a ich materiálové
parametre.
Dlhodobo sa špecializuje na kvantitatívnu infračervenú termografiu a infračervenú termografickú diagnostiku
konštrukčných materiálov, najmä materiálov na báze polymérov, na výskum tepelných a viskoelastických vlastností
polymérov a polymérnych nanokompozitov, ako aj na štúdium vplyvu ionizujúceho žiarenia na ich fyzikálne
vlastnosti. Neoddeliteľnou súčasťou jeho výskumnej činnosti je i matematické modelovanie termofyzikálnych
procesov a počítačové spracovanie rozsiahlych sérií experimentálnych dát.
Katedra priemyselného dizajnu so zameraním vedecko-výskumnej činnosti na:
Analýzu vplyvu štruktúry materiálov na vlastnosti výrobkov určených pre technické a odevné textílie. Problematiku
štruktúry priadzí a ich vplyv na vlastnosti dĺžkových a plošných textílií.
Zisťovanie fyzikálno-mechanických vlastností materiálov, matematicko-štatistické závislosti dĺžkových a plošných
textílií, technickými textíliami určenými predovšetkým pre automobilový priemysel a armádu, aplikácia
inteligentných textílii do technického a odevného sektoru, vplyvu pórovitosti a zaplnenia na tepelnoizolačné
vlastnosti materiálov, závislosťami vplyvu fyziológie odievania na odevný komfort v odevnom dizajne a aplikáciou
vlastností materiálov pre dizajn výrobkov
Kvalitu Fakulty priemyselných technológií so sídlom v Púchove potvrdzuje aj hodnotenie nezávislej agentúry
ARRA, v ktorom sa FPT každoročne od svojho vzniku umiestňuje v rade 24 hodnotených technických fakúlt
Slovenskej republiky v prvej desiatke.
prof. Ing. Ján Vavro, PhD.
dekan Fakulty priemyselných technológií so sídlom v Púchove
Trenčianskej univerzity Alexandra Dubčeka v Trenčíne
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ISSN 0018-8069
Materiálové inženýrství
Material Engineering
materiálové inženýrství
Traits of Specific Composites with Elastomer Matrix and Steel-cord
Reinforcement during Tensile Load
Zvláštnosti specifických kompozitů s elastomerovou matricí a ocelokordovou
výztuží při zatěžování tahem
doc. Ing. Jan Krmela, PhD., University of Alexander Dubček in Trenčín, Faculty of Industrial Technologies, I.
Krasku 491/30, 020 01 Púchov, Slovakia
The paper deals with static experiments of specific long-fibre composites with steel-cord and elastomer matrix.
These composites are used in the tire as steel-cord belt layers. During usage a combination of various forms of
mechanical loading occurs in the casing of a tire. The most stressed part is the steel-cord belt. Test samples were
prepared from the belt with a given configuration of angles of the cords to the direction of loading. Samples were
prepared with symmetrically and non-symmetrically arranged reinforcement. These traits for non-symmetrical
specimens are described in the paper. From the results of the tensile tests it can be stated that in the case of
problematic production of belt with the angle of cords +-23° a certain replacement for a belt with a better
producible cord angle +-45° can be performed, while the results of tensile tests of carved specimens with nonsymmetrically arranged reinforcement in the given angle of the cords are similar. The results from experiments can
be used as verification data for comparison of results from computational modelling to experimental data.
Článek se zabývá statickými experimenty specifických dlouhovláknových kompozitů s elastomerovou matricí
a ocelokordovou výztuží. Tyto kompozity jsou typické např. pro pláště osobních pneumatik, kde se vyskytují ve formě
tzv. vícevrstvých ocelokordových nárazníků. V plášti pneumatiky při provozování dochází ke kombinaci různých
forem mechanického zatěžování, přičemž nejvíce je namáhán ocelokordový nárazník. Pro pochopení vlivů působení
mechanického zatěžování na nárazníkovou část pláště pneumatiky byly z nárazníku vyrobeny zkušební vzorky
s danou konfigurací úhlu kordů ke směru zatěžování. Byly vyrobeny vzorky se symetricky a nesymetricky
uspořádanou výztuží. V článku je pozornost věnována nesymetrickým zkušebním vzorkům s konfigurací kordů
+22,5°/+67,5°, které byly připraveny z nárazníku +-23° a s konfigurací 67°/+23°, které byly vyřezány z nárazníku
+-45°. V článku jsou zhodnoceny výsledky ze statických zkoušek v tahu vybraných zkušebních vzorků. Z výsledků ze
zkoušek v tahu lze konstatovat, že v případě problematické výroby nárazníku s úhlem kordů +-23° lze provést
určitou náhradu za nárazník s lépe vyrobitelným úhlem kordů +-45°, přičemž výsledky ze zkoušek v tahu vyřezaných
vzorků s nesymetricky uspořádanou výztuží v daném úhlu kordů jsou obdobné. Výsledky z experimentů mohou být
použity jako verifikační údaje pro porovnání výsledků z výpočtového modelování s experimentálními daty. Na
základě výsledků z experimentů zkušebních vzorků, které jsou částí celého souboru výzkumné činnosti autora, jsou
navrhovány nové konstrukční směry plášťů pneumatik např. v oblasti úhlů tažení kordů v náraznících.
The paper deals with the specific composites with
elastomer matrix and steel-cord reinforcement. These
composites are typical, for example: for a passenger
tire-casing where they occur in the form of multi-layer
steel-cord belt.
During usage a combination of various forms of
mechanical loading (tension, bending and shear) occurs
in the tire-casing. The steel-cord belt is extremely
stressed by this loading. Moreover, the temperatures
inside of the tire-casing can be in the range from -40 to
120 °C according to weather conditions and operating
conditions which are often not kept. These include, for
example: the typical overloading of trucks, deflated tires
or the combination of these two factors is also very
frequent.
The interaction of mechanical and thermal effects causes
the degradation processes occurring in the most exposed
parts of the tire. They are manifested by the separation of
layers of belts. It is a delamination of belt layers mostly
in the places of their ends (fig. 1). From the aspect of
durability and the safety indicators of the casing, the
occurrence of separations is unacceptable [1].
7
Materiálové inženýrství
Material Engineering
Experiments are performed for purposefully separated
parts of the tire-casing, such as tire tread with belt layer
[2] and also for test samples from the steel-cord belt
itself because of understanding the effects of
mechanical loading on the belt part of the tire-casing
and creation of the possible proposal for construction
measures in the order to increase the resistance to
rupture and the strength parameters of the belt.
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
arranged under a double angle of +-45°, i.e. the angle
between the cords is 90°. This angle does not
correspond to the configuration of cords commonly
used in tire-casings. The second type of belt was made
for the purpose of analysis how the double values of the
angle between the cords can affect stiffness
characteristics.
First type of belt with the angle of cords +-22.5° was
harder to produce in terms of compliance with the most
accurate angle between cords. Belt with an angle of +-45°,
where the reinforcement between layers clutches an
angle of 90° was easier to produce with regard to
the requested angle. Subsequently, the belt test samples
with the desired orientation of cords were carved using
the water jet. Test samples were made in the shape of a
rectangle with dimensions of 15 mm  125 mm (width 
length) and with symmetrically and non-symmetrically
arranged reinforcement to the direction of loading.
Thickness of the samples was approximately 4 mm.
Samples with a larger width of 25 mm were also
prepared.
Fig. 1 Cross section of a passenger tire-casing at the area of the end
of belts with detail of steel-cord structure
Obr. 1 Příčný řez pláštěm osobní pneumatiky v místě ukončení
nárazníků s detailem struktury ocelokordů
Experiment
The samples with symmetrical configuration of +-22.5°
and non-symmetrical samples with angles of cord
+22.5°/+67 were carved 5° from the belt +-22.5°. From
The samples with symmetrical configuration of +-45°
and non-symmetrical samples with angles of cord
67°/+23° were carved from the belt +-45°. Layout of the
reinforcement in the non-symmetric test samples is
shown on fig. 2.
The static tensile and bending tests are included among
the basic experiments and they are carried out for the
belt test samples with regard to the possibilities of
testing devices because it is very difficult to simulate
the combination of tension and bending loadings at the
simultaneous dynamic and thermal stress under
common laboratory conditions while the given
experimental procedure depends on the available testing
equipment.
Fig.
The results of the static tensile tests for selected belt test
samples with regard to the angle of pulling the cords to
the load direction are evaluated in the paper and
the traits of the behavior of composite samples during
loading are also shown.
Steel-cord belts were prepared from the raw materials
used in the production of tires using a vulcanizing press.
Cords have a wire construction 2+20.30 mm used in
belts tire-casings and the standard alluvial mixture for
steel-cord of passenger tires is used as a matrix. Using
the mentioned technological procedure, two types of
double-layer steel-cord belts were prepared with regard
to the angle of the cords. Their dimensions were
260260 mm. The first type of belt has cords similar to
a real tire-casing with the angle of cords of +-22.5°, i.e.
the cords in layers have an angle of 45° between each
other. The second type of belt has cords which are
2
Obr. 2
Configuration of cords in test samples to the direction of
loading
Konfigurace kordů ve zkušebních vzorcích ke směru
zatěžování
The static test device for tensile tests Hounsfield H20KW was used for tensile tests. Loading rate was
20 mm/min. Clamping of samples in the jaws of the test
device was at 92 mm. When the test samples with the
non-symmetric layout of reinforcement were loaded they
started to twist in the direction of the loading forces. This
occurred mainly in samples with a width of 25 mm. It
should be noted that some twisting occurred immediately
after the cutting of belt samples.
Results and discussion
Results from tensile tests for selected test samples with
a width of 15 mm are presented by dependencies of
tensile force on elongation (deformation) and tensile
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Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
stress on strain (fig. 3). The results show that nonsymmetric specimens +22.5°/+67.5° prepared from belt
+-23° have similar values like samples -67°/+23° cut of
the belt +-45°.
Stiffness of samples with configuration +22.5°/+67.5° is
slightly higher than the stiffness of samples -67°/+23°
(up to 10-15% difference). If the change of the angles
during arrangement of the cords is neglected (real angle
of the belt +-23° could differ because of the harder
production from the desired angle - angle tolerance is
approximately +-2°), because it could be the source of
Materiálové inženýrství
Material Engineering
this stiffness difference, it can be stated that the stiffness
of samples from both configurations of cords is
approximately the same. Another, but less significant
influence on the results could be caused by the
differences of geometrical parameters of samples, such
as the distance of cords in each layers of the belt
between themselves and any other possible inaccuracies
from the production of samples using the water jet
cutting. The samples prepared by the technology of
water jet cutting had on their edges the characteristic
notches (serrations).
Fig. 3 Results from the tensile test for selected configuration of cords
Obr. 3 Výsledky ze zkoušky v tahu pro vybrané konfigurace kordů
An identical experimental conclusion was acquired for
the test samples, the reinforcement of which was formed
by a thin wire with a diameter of 0.89 mm which is
commonly used for the production of bead wires.
If we compare the behavior of test samples with nonsymmetrically
and
symmetrically
arranged
reinforcement, we can talk about certain twisting of
non-symmetrical samples during the experiments.
Simultaneously there are various forms of straying in
the samples. As an example we can use the typical
twisting of test samples with non-symmetrical
reinforcement +23/+67° (Fig. 4).
in the given angle of the cords are similar. That
conclusion applies both for wire reinforcement and also
for reinforcement consisting of a thin wire. Test samples
with non-symmetrically arranged reinforcement start to
twist characteristically when loaded.
The results of the experiments can be used as
verification data for comparison with results from
computational modeling to experimental data.
Based on the results from experiments for belt samples,
which are part of the whole set of research of the author,
new design directions of casing of tires are proposed.
For example: innovation in the angle of arrangement of
the steel cords in the belt of the casing.
Literature
Fig. 4
Obr. 4
Twisting of test sample with non-symmetrical reinforcement
+23/+67° with the width of the sample 25 mm during tensile
test [2]
Nakrucování zkušebního vzorku s nesymetrickou výztuží
+23/+67° se šířkou vzorku 25 mm při zkoušce v tahu [2]
Conclusions
In the case of more difficult production of belts with
angle of cords +-23°, a certain replacement for a belt
with better producible angles of cords +-45° can be
performed, while the results of tensile tests of carved
samples with non-symmetrically arranged reinforcement
[1] KOŠTIAL, P., KRMELA, J., FRYDRÝŠEK, K., RUŽIAK, I.
The Chosen Aspects of Materials and Construction Influence on
the Tire Safety. Composites and Their Properties. Chapter 13.
Ning Hu (Ed.), Croatia: InTech, Rijeka, 2012, p. 265-298. ISBN
978-953-51-0711-8. Open access: <http://www.intechopen.com/
books/composites-and-their-properties/the-chosen-aspects-ofmaterials-and-construction-influence-on-the-tire-safety>
[2] KRMELA, J., PEŠLOVÁ, F., KURAJDOVÁ, K. Macrostructure
and Microstructure Study of Tyre Composites for Computational
Modelling. In International scientific conference Material
Science and Manufacturing Technology – MITECH ’08. Prague,
Czech Republic: 2008, p. 109-112. ISBN 978-80-213-1792-5
Review: prof. Ing. Ján Vavro, PhD.
prof. Dr. Ing. Milan Sága
9
Materiálové inženýrství
Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Selected Mechanical and Photosensitive Properties of HEC/HEC-Cin Blends
Vybrané mechanické a fotochemické vlastnosti zmesí HEC/HEC-Cin
Ing. Vladimíra Krmelová, PhD., Ing. Katarína Kostelanská, PhD., doc. Ing. Jan Krmela, PhD.,
doc. Ing. Iva Sroková, PhD., University of Alexander Dubček in Trenčín, Faculty of Industrial Technologies,
I. Krasku 491/30, 020 01 Púchov, Slovak Republic
This paper deals with preparation of HEC/HEC-Cin polymeric blends and study of their selected mechanical
properties (Young’s modulus) and photosensitive behavior. HEC-Cin derivatives were prepared by chemical
modification of HEC with cinnamic acid and cinnamoyl chloride in different reaction media. The prepared HECcinnamates were characterized by Fourier-transform infrared (FT-IR) spectroscopy and used as additives to blends
with hydroxyethylcellulose (HEC). Mechanical properties of thin films of HEC/HEC-Cin polymeric blends and pure
HEC and HEC-Cin were studied by dynamic mechanical analysis (DMA). The photochemical behavior of HEC-Cin
films under UV irradiation were investigated too.
Príspevok sa zaoberá prípravou HEC/HEC-Cin polymérnych zmesí a štúdiom ich vybraných mechanických
a fotochemických vlastností. Cinamáty hydroxyetylcelulózy (HEC-Cin) sa pripravili chemickou modifikáciou HEC
kyselinou škoricovou a chloridom kyseliny škoricovej v reakčných prostrediach DMSO a DMF/pyridín za katalýzy
4-DMAp a aktivácie kyseliny dicyklohexylkarbodiimidom (DCCI) za rôzných reakčných podmienok. Následne sa
HEC-Cin charakterizovali FT-IR spektroskopiou a použili ako aditíva v polymérnych zmesiach s HEC. Z dvoch
cinamátov HEC-Cin2 a 4 sa pripravili filmy ako polymérne zmesi HEC/HEC-Cin v pomeroch 10:1, 1:1 a 5:1
odliatím z vodných roztokov. Na porovnanie vlastností sa pripravili filmy z čistej HEC a HEC-Cin. U pripravených
filmov z HEC-Cin derivátov ako aj ich zmesí s HEC sa hodnotili ich mechanické vlastnosti DMA metódou. Namerali
sa hodnoty elastického modulu E´ a viskózneho modulu E´´ v závislosti od teploty a z nich sa vypočítali hodnoty
Youngovho modulu. Metódou DMA sa zistilo, že prítomnosť vybraných esterov HEC-Cin 2 a 4 spôsobila nárast
Youngovho modulu pre všetky zmesi s HEC oproti východiskovej HEC a majú pozitívny vplyv na kvalitu filmov, čím
zlepšujú ich mechanické vlastnosti. Taktiež sa hodnotila stabilita HEC-Cin filmov voči UV žiareniu.
In recent years, polysaccharides as biopolymeric
materials have received considerable interest as a source
of renewable materials based on wood biomass and
agricultural residues. These naturally occurring
biodegradable and recyclable materials are regarded as
promising alternatives for the production of biofuels and
replacement of the synthetic polymers, consequently
reducing the global dependence on fossil hydrocarbons
[1]. Hydroxyethylcellulose (HEC) is a nonionic
polysaccharide, commercially produced with a various
degree of substitution (DS). The derivatives with various
properties can be obtained by chemical functionalization
of HEC. The surface-active properties are one of them
where derivates can be used as polymeric surfactants [2]
and others can be additives to polymers [3] or
antioxidative properties can be also mentioned in relation
to chemical functionalisation of HEC [4]. In this study,
prepared and characterized HEC-Cin derivatives were
used for preparation of the polymeric blends. The
polymeric blends composed of HEC- cinnamates and
HEC were prepared as thin films by cutting methods and
their mechanical properties as well as photosensitive
behavior under UV irradiation were investigated.
Experiment
Germany) was used for preparation of HEC cinnamates
(HEC-Cin) and for preparation of polymer blends
HEC/HEC-Cin as a matrix. Prepared HEC-Cin derivatives
were used as additives in blends with HEC and prepared
according reaction conditions in tab. 1.
FT-IR spectroscopy: Fourier-transform infrared (FT-IR)
spectra were obtained on the Nicolet 6700 spectrometer
with an ATR extension piece (Smart orbit diamond)
with using 128 scans at resolution of 4 cm-1 at the
Institute of Chemistry, SAS (Bratislava, Slovakia).
UV spectroscopy: UV spectra of HEC-Cin derivatives
dissolved in water (4 mg/10 ml) were obtained on the
SpectroFlex 6600 (WTW Weilheim, Germany).
Preparation of HEC/HEC-Cin blends from aqueous
solutions: The blends from HEC/HEC-Cin were prepared
from 1.66 % solution of HEC as a matrix and HEC-Cin
solutions in the mass ratio 1:1, 10:1 and 5:1 under stirring
in a magnetic stirrer at room temperature. The prepared
high viscous solution was poured into Petri dish with a
diameter of 4.5 cm. The prepared mixture was allowed to
evaporate freely in the horizontal support from 7 to 10
days approximately. The dry film was peeled from the
Petri dish. The films from pure HEC and HEC-Cin were
prepared analogically.
Materials and methods: Hydroxyethylcellulose (HEC,
MS = 2.5; DS = 1.0) from HOECHST (Frankfurt,
10
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ISSN 0018-8069
Materiálové inženýrství
Material Engineering
Tab. 1 Reaction conditions, yield and characterization of HEC-Cin prepared with cinnamic acid (CA) activated by DCCI in DMSO and with
cinnamoyl chloride (ClCA) in DMF/pyridine under various conditions at 50 °C
Tab. 1 Reakčné podmienky, výťažky a charakteristické spektrálne dáta HEC-Cin derivátov pripravených modifikáciou s kyselinou škoricou
a chloridom kyseliny škoricovej za rôznych reakčných podmienok
HEC-Cin
Mass ratio HEC:CA:DCCI
Time /h
Yield (g/g)a
υ(CO, C=C)/cm-1
λmax /nm
DSc
1
1:1:0.1
0.5
0.94
1700, 1633
281
0.01
2
1:2:2
0.5
0.98
1705, 1635
280
0.08
3
1:3:0.1
0.5
0.86
1707, 1635
280
0.06
b
HEC:ClCA 1:6
3.0
0.86
1716, 1635
280
4
Expressed as g of the recovered derivative per g HEC (on dry mass basis), b Reaction temperature was 90 °C, c Degree of substitution (DS) was
determined as is described in [5].
a
Dynamic-mechanical analysis (DMA) of HEC/HEC-Cin
blends: The dynamic-mechanical properties of the
prepared blends were evaluated by DMA methods using
Perkin Elmer PYRIS Diamond equipment from 25 to
70 °C with a frequency of 0.5 Hz and a heating rate of
3 °C/min. During testing, the dynamic-mechanical
property parameters of storage (E') and loss (E'') moduli
were obtained as a function of temperature. The values
of Young’s modulus (E) were calculated from storage
and loss modulus [6]. The samples for DMA were
prepared by cutting strips from the cast films with
dimension 20 mm  10 mm  0.1 mm.
Irradiation of the HEC-Cin films with UV light: Before
the irradiation of the HEC-Cin films as well as pure HEC
film, the absorbance of films were measured (time = 0).
Subsequently the films were exposed to UV light
(wavelengths from 200 to 350 nm) at a distance of 30 cm
for different time intervals (1-40 min). After each
exposure interval, UV spectra of the films were measured
in the UV region (200-400 nm) and absorbance at
275 nm was recorded. UV spectra of the thin films were
measured on the spectrometer SPEKORD UV-VIS,
equipped with a digital-analog convertor METEX M4650 CR, Carl Zeiss Jena GmbH (Jena, Germany).
Results and discussion
Water-soluble HEC-Cin derivatives were used
as additives to unsubstituted HEC with the aim to
evaluate their mechanical properties. DMA method was
used for the evaluation of the dynamic-mechanical
properties of the prepared HEC/HEC-Cin derivatives
blends as well as films of pure HEC and HEC-Cin
derivatives. The value of Young’s modulus was
calculated from storage and loss modulus as a function
of temperature and results are given in fig. 1 and 2.
From literature it is known, that smaller Young’s
modulus causes the easier material deformation.
Therefore, Young’s modulus is an important indicator
for evaluation of flexibility of material, expressing the
volume toughness of material. The Young’s modulus of
all tested blends (HEC/HEC-Cin2 and HEC/HEC-Cin4)
is higher than HEC matrix. When the amount of HECCin in blend-film increased, the Young’s modulus
increased too. This result can be attributed to
the flexibility of HEC-Cin chain. Fig. 1 shows that
prepared blends with various amount of the HEC-Cin
show strong dependence of the Young’s modulus on the
amounts of the HEC-Cin2 in the blends. The
HEC/HEC-Cin2 (1:1) blend as well as pure HEC-Cin2
film exhibit slightly higher values of Young’s modulus
than HEC/HEC-Cin2 (10:1) blends. From the practical
point of view, the best blend was prepared from mixture
HEC/HEC-Cin2 with ratio10:1.
Fig. 1
Dependence of Young's modulus on temperature of
HEC/HEC-Cin2 blends compared to HEC and pure-HECCin2 films
Obr. 1 Závislosť Youngovho modulu od teploty filmov zmesí
HEC/HEC-Cin2 (1:1 a 10:1) v porovnaní s filmami HEC a
HEC-Cin2
The fig. 2 represents the similar dependence of Young’s
modulus but it is slightly different in comparison to
fig. 1 because the blends HEC/HEC-Cin4 with ratio 1:1
exhibit higher values of Young’s modulus than film
from pure HEC-Cin4 which was used as an additive.
The curve of HEC/HEC-Cin4 (5:1) blend showed a fall
of modulus at 45 °C to minimum and it is probably
caused by higher influence of HEC on the properties of
the blends as well as by lower extent of cinnamoyl
group in used additive HEC-Cin4. In general, the
addition of HEC-Cin caused an increase of Young’s
modulus for all blends with various amount of additives
in comparison to HEC. It means that the HEC-Cin has
a positive effect on the toughness of the HEC films.
In the next part of work the photosensitive behavior of
selected films of HEC-Cin derivatives was studied.
The photosensitive behavior of the synthesized HECCin derivatives with various degree of cinnamoylated
HEC was evaluated after irradiation of the films.
Expected ability to crosslink under UV irradiation was
11
Materiálové inženýrství
Material Engineering
not confirmed for the prepared HEC cinnamates. The
photochemical reaction was carried out using UV light
Fig. 2 Dependence of Young's modulus on temperature of
HEC/HEC-Cin4 blends compared to HEC and pure HECCin4 films
Obr. 2 Závislosť Youngovho modulu od teploty filmov zmesí
HEC/HEC-Cin4 (1:1 a 5:1) v porovnaní s filmami HEC a
HEC-Cin4
with wavelength 200-350 nm (commercially UV lamp).
After each exposure interval UV spectra of the films
were measured. The dependences of absorbance at
275 nm on exposure time are given in fig. 3. As can be
seen, the maximum absorbance of films at wavelength
275 nm degreased during fifth minutes but it was
relatively invariable after 10 min.
In the next part of work the photosensitive behavior of
selected films of HEC-Cin derivatives was studied.
The photosensitive behavior of the synthesized HECCin derivatives with various degree of cinnamoylated
HEC was evaluated after irradiation of the films.
Expected ability to crosslink under UV irradiation was
not confirmed for the prepared HEC cinnamates. The
photochemical reaction was carried out using UV light
with wavelength 200-350 nm (commercially UV lamp).
After each exposure interval UV spectra of the films
were measured. The dependences of absorbance at
275 nm on exposure time are given in fig. 3. As can be
seen, the maximum absorbance of films at wavelength
275 nm degreased during fifth minutes but it was
relatively invariable after 10 min.
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
before and after exposure to UV light during 14 days (not
showed). By comparison of these FT-IR spectral data no
changes have been obtained, any reduced bands have not
been showed as well as there was not creation of new
bands. Namely band at 1633 cm-1 which is attributed to
the C=C bond was without changes. Therefore the
crosslinking of the C=C bonds was not determined as
well as gel suspension or insoluble polymers has not been
arisen. The absorbed wavelength with corresponding
energy was used for the isomerization of the stable trans
form of the C=C bond to the unstable cis form. After
some time, derivate was reversed to the stable trans form.
Nevertheless, it can be assumed that HEC-cinnamate has
the best antioxidant properties, the ability to
„scavenge“free radicals from UV radiation. For
confirmation of this assumption, it is necessary to
determine the activity of the other derivatives.
Conclusions
Partially water-soluble HEC-Cin derivatives were
prepared, characterized by FT-IR and UV spectroscopy
and used as additives to the HEC matrix. The polymer
blends HEC/HEC-Cin as films were prepared and their
mechanical properties were evaluated. Application of
HEC-Cin derivatives into HEC matrix was connected
with enhanced mechanical properties. Even low amounts
of HEC-Cin as additive in polymeric blend led to
improvement of HEC elasticity. All blends have higher
values of Young’s modulus in comparison to HEC film.
The photosensitive behaviour of the HEC-Cin films
with various extent of cinnamoylation of HEC after
irradiation with UV light showed that expected ability to
crosslink under UV irradiation was not confirmed.
Absorbed wavelengths or energy from UV light was
used to trans – cis isomerisation of HEC-Cin.
Acknowledgement
This work was financially supported by the Slovak
Grant Agency VEGA, projects No. 2/0062/09.
Literature
[1] KROCHTA, J.M., BALDWIN, E.A., NISPEROS-CARRIEDO,
M.O. Edible coatings and films to improve food quality.
Technomic Pub. Company, Lancaster, 1994, 379 p.
[2] LANDOLL, L.M. Nonionic polymer surfactants. Journal of Polymer
Science Part A: Polymer Chemistry, 1982, Vol. 20, p. 443-455
[3] MAZÍKOVÁ, V., SROKOVÁ, I., MOŠKOVÁ, D., SASINKOVÁ, V.,
JANIGOVÁ, I., CSOMOROVÁ, K., EBRINGEROVÁ, A. Preparation
and Properties of carboxymethylstarch ester and its blends with
polyethylene. Fibres and Textiles, 2007, Vol. 14, (3-4), p. 22-27
[4] WONDRACZEK, H., KOTIAHO, A., FARDIM, P., HEINZE, T.:
Photoactive polysaccharides. Carbohydrate Polymer, 2011, Vol.
83, p.1048-1061
Fig. 3 Dependency of absorbance (at 275 nm) of HEC-Cin films
with different degree of cinnamoylation on exposition time
Obr. 3 Závislosť absorbancie (pri 275 nm) filmov HEC-Cin s
rôznym DS v závislosti od času expozície UV žiarenia
[5] KOSTELANSKÁ, K. Zámerná funkcionalizácia vybraných
biopolymérov a štúdium ich vlastností, Dissertation work, FPT
TnU AD, Púchov, 2012, 98 p. (in Slovak)
[6] MENARD, K. Dynamic Mechanical Analysis – A Practical
Introduction. CRC Press LLC, Boca Raton, 1999, p. 208, ISBN 08493-8688-8
Review: prof. Dr. Ing. Milan Sága
prof. Ing. Tatiana Liptáková, PhD.
To confirm the assumption that the cinnamoylate groups
in HEC-cinnamates can be used as „traps of free radicals“
the FT-IR spectra of derivate HEC-Cin2 was measured
12
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Materiálové inženýrství
Material Engineering
The Influence of Addition of the Biofuels on the Rubber Seals in Aero Engines
Vplyv prídavku biopalív na gumové tesnenia leteckých motorov
doc. Ing. Milan Olšovský, PhD., Ing. Michal Dubovský, Department of Material Technologies and Environment,
Faculty of Industrial Technologies, University of Alexander Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov,
Slovakia
Nowadays, the airline industry or world-wide companies in the aerospace industry are forced to find new ecological
alternatives of traditional fuels which should substitute aviation fuel and kerosene. In aero turbo engines (ATCE).
The rubber seals on the basis NBR (nitrile- butadiene rubber) with different contents of acrylonitrile are the most
commonly used for production of seals. This NBR is characterized by excellent physical and mechanical properties.
This paper presents the effects of critical operating conditions and the addition of biofuels to aviation fuel in
relation to seals for aircraft engines. These seals were exposed to extremely low and higher temperature as well as
mixture of aviation fuel JET A1 and biofuel (methylester of rapsoil oil - FAME) for 136 days. The results indicate
that addition of 10 and 20 wt. % biofuels into aviation fuel JET A1 causes decrease of the physical and mechanical
properties for these used seals.
V práci autori prezentujú výsledky vplyvu prídavku biozložky metylesterov kyselín repkového oleja (MERO)
k leteckému palivu (JET A1) na gumové tesnenia leteckých motorov. Ako gumové tesnenia sme použili štandardne
používané gumové tesnenia v leteckých turbokompresorových motoroch. Sú tesnenia na báze NBR, ktorý patrí medzi
olejovzdorné kaučuky. Experimenty boli realizované pri kritických podmienkach, v ktorých pracujú letecké motory –
a to zvýšená teplota +100 °C a znížená teplota -20 °C. Pri týchto teplotách boli gumové tesnenia vystavené počas
136 dní (3264 hodín) expozícii zmesného leteckého paliva, ktoré pozostávalo zo zmesi leteckého benzínu a prídavku
biozložky MERO. Na základe doterajších našich výsledkov sme zvoli obsah zložky MERO len 10 a 20 hmot. %
Namerané výsledky boli porovnávané so štandardom, ktorý predstavovalo gumové tesnenie, ktoré nebolo vystavené
vplyvu žiadneho paliva. Pri napučaní vulkanizátov dochádza k zhoršeniu mechanických vlastností (pokles pevnosti
v ťahu a štruktúrnej pevnosti) a tým aj k zhoršeniu funkčných a úžitkových vlastností. Pokles tvrdosti gumových
tesnení bol do 10 %. Tento pokles nebol taký dramatický aby v negatívnom slova zmysle výrazne ovplyvňoval
funkčnosť týchto tesnení.
effective from the point of the cost. According to
obtained results, it was proved that the maximum
addition of MERO into the aviation fuel is up to
30 wt. %.
Addition of biofuels which are commonly used is
closely connected with a specific regulation of the
European Union from 2003. Moreover, there is the
preparation of the regulation including utilisation of
biofuels also in the aviation gasoline and kerosene. The
composition of aviation biofuels is different and
therefore the different seals of engine fuel system have
to be used and the closer characteristics of effect of
biofuel additive has been still at the beginning in
relation to aviation industry. The main disadvantage of
biofuels is based on their limited availability (oils and
lipids) as well as limited sources and high cost.
Nowadays, Biofuel “MERO” of the second generation
is still the only one alternative fuel which can be used in
the common combustion engines. In the aero-turbo
compression engines, there is the contact between
rubber seals and mixture of biofuel MERO and aviation
fuel JET A1. From the aspect of rubbers resistant to
swelling, there are not any special requirements, e.g.
extreme strength and wear resistance and therefore it is
advantageous to use the higher amount of black carbon
which are less active because this technique is more
Results and discussion
Experimental measurements were performed at the
Faculty of Industrial Technology in Púchov in
cooperation with the Faculty of Aeronautics, Technical
University in Košice. The object of this work was to
investigate the influence of two concentrations of added
biofuel FAME into aviation fuel JET A1and monitor the
impact of such fuel on the rubber seals ATCE. The
original seals were immersed into solutions and these
rubber seals were exposed to extremely low and high
temperatures. Fuel composition and conditions of
measurement are shown in tab. 1. These parameters
were measured on rubber seals: relative change of
weight (ISO 1817), relative change of hardness
(ISO 48), tensile strength (ISO 37). We have made two
parallel measurements for each one condition.
13
Materiálové inženýrství
Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Tab. 1 Test conditions
Tab. 1 Podmienky skúšok
Libelling
samples
0
1A, 1B
2A, 2B
3A, 3B
4A, 4B
thus the mobility of macromolecules was probably
increased. Hardness of the samples had decreasing
tendency in dependence on time in relation to impact of
fuel. It occurred because of bigger distances between
individual macromolecules and this problem is closely
connected with plasticizing effect of FAME.
The test conditions
Standard – without fuel action;
Room temperature
Fuel JET A1 : MERO = 90 : 10;
Temperature: - 20 °C
Fuel JET A1 : MERO = 80 : 20;
Temperature: - 20 °C
Fuel JET A1 : MERO = 90 : 10;
Temperature: 100 °C
Fuel JET A1 : MERO = 80 : 20;
Temperature: 100 °C
Tab. 3 Relative change of specific hardness for sample at -20 °C
versus time
Tab. 3 Relatívna zmena tvrdosti vzoriek v závislosti od času pri -20 °C
Influence of
fuel in time
(h)
168
336
480
864
1200
1488
1992
2304
2496
2664
2952
3264
Properties of rubber seals exposed to fuel mixture
at -20 °C
The results of measurements relating to changes of
weight and hardness of the rubber seals, which was
exposed to temperature -20 °C are shown in the tab. 2.
The first stage was connected with absorption of liquid
by rubber and then there was decrease of weight after
1200 hours. The initial increase is related with
solubility of rubbers and it includes increase of the
total volume of samples and after that there was the
occurrence of weight decrease which was connected
with stabilization of dissolution equilibrium a this
decrease of weight was probably caused by solving
and leaching some soluble parts of rubber seals
(mainly non - rubbers additives). Finally, the weight
increased again, and it has been caused by swelling
rubber by liquid, or it could be caused by possible
chemical reaction of rubber with liquid.
1B
9.53
10.43
10.35
10.71
8.59
9.48
10.17
8.95
8.71
-
2A
11.71
12.05
13.08
16.28
11.79
11.64
8.08
7.51
7.19
7.12
7.36
7.31
1B
-1.47
-2.20
-2.93
-5.49
-6.23
-4.76
-7.32
-8.79
-9.22
-
2A
-1.47
-1.83
-3.66
-6.59
-7.69
-4.03
-5.86
-8.42
-8.80
-9.52
-9.61
-9.65
2B
-0.73
-2.93
-3.66
-6.22
-6.59
-5.13
-5.86
-7.32
-7.88
-
Tab. 4 Relative change of specific weights for sample at 100 °C
versus time
Tab. 4 Relatívna zmena hmotnosti vzoriek v závislosti od času pri
100 °C
Influence of
fuel with
time (h)
37
62
86
150
221
282
308
369
409
435
509
553
Relative change of weight (%)
1A
9.31
9.87
9.77
10.00
8.71
10.05
10.15
9.50
9.12
9.03
9.49
9.25
1A
-2.93
-4.39
-4.03
-6.22
-7.32
-8.06
-6.59
-8.06
-9.89
-10.62
-10.52
-10.48
Properties of rubber seals exposed to fuel mixture at
100 °C
Tab. 2 Relative change of specific weights for sample at -20 °C
versus time
Tab. 2 Relatívna zmena hmotnosti vzoriek v závislosti do času pri
-20 °C
Influence of
fuel in time
(h)
168
336
480
864
1200
1488
1992
2304
2496
2664
2952
3264
Relative change of hardness (%)
2B
4.55
5.12
4.23
5.31
2.88
3.59
3.23
2.70
2.51
-
Relative change of weight (%)
3A
7.22
9.46
9.03
10.33
18.47
15.57
12.90
13.12
13.55
12.09
11.98
11.88
3B
8.33
8.33
11.26
11.65
16.63
15.85
15.08
13.54
13.96
-
4A
9.47
10.81
12.10
14.75
23.32
23.52
22.83
22.54
22.79
19.36
17.57
17.66
4B
15.05
13.54
15.88
17.76
35.29
28.82
28.83
28.82
31.27
-
Rubber seals became brittle and shiny (it was easy to
break them) after 400 hours and during the mentioned
time, the rubber seals were exposed to higher
temperature and solution of biofuel with aviation fuel,
rubber seals became brittle and shiny (it was easy to
break them) after 400 hours and during the mentioned
time, the rubber seals were exposed to higher
temperature and solution of biofuel with aviation fuel.
Therefore it was not possible to perform tensile tests for
them. It was probably caused by extraction and partial
Increasing volume of MERO in fuel which has
influence on rubber rings as "plasticizer" caused the
decrease of hardness of rubber seals (tab. 3). MERO has
influence on rubber matrix as an internal plasticizer and
14
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Materiálové inženýrství
Material Engineering
evaporation of plasticizer (and other volatile substances)
from the rubber mixture used to make this seal. Change
of weight of rubber seals was within the range of 20 –
30 wt. % and it is much more than at -20 °C. This
means that increased temperature also accelerates
degradation of the seals. The most significant change of
weight was observed for samples 7 and 8 which have
been exposed to fuel with addition 20 % wt. of MERO,
and it means that mixture of biofuel and aviation fuel
and higher temperature has destruction influence on
these rubber seals. Decrease of hardness was
approximately the same for both test conditions and
there was not any substantial effect on the hardness by
fuel composition.
complex simulation of real conditions of their usage.
The results show that higher temperature accelerates the
destruction of rubber seals when there is the increase
content MERO in fuel.
Tab. 5 Relative change of specific hardness for sample at 100 °C
versus time
Tab. 5 Relatívna zmena tvrdosti vzoriek závislosti od času pri
teplote 100 °C
[3] HOCKO, M. Použitie zmesi biopaliva „MERO“ s leteckým
petrolejom pre pohon leteckých turbokompresorových motorov,
Zborník abstraktov zo 7. Medzinárodnej vedeckej konferencie
„Nové trendy rozvoja letectva“, 6. – 8. 9. 2006, LF TUKE
Influence of
fuel with
time (h)
37
62
86
150
221
282
308
369
409
435
509
553
Literature
[1] ANDOGA, R, MADARÁSZ, L, FÖZÖ, L. Situational modeling
and control of a small turbojet engine, In MPM 20, IEEE
International Conference on Computational Cybernetics, Tallin,
Estonia, 2006, p. 81-85
[2] HOCKO, M. Možnosti využitia netradičných palív pre pohon
leteckých turbokompresorových motorov, In 6. Medzinárodná
konferencia Nové trendy v rozvoji letectva, sekcia 1. letecké
strojárstvo a environmentalistika, VLA Košice 9-10 September.
p. 21 – 25
[4] HOCKO, M, BAJUSZ, P. Possibilities of using the
unconventional fuels to drive aeronauctical turboject engines,
Acta Avionica, 2006, ročník VIII; Košice Letecká fakulta TUKE,
p. 5 – 12.
Relative change of hardness (%)
3A
-1.47
-2.93
-3.29
-4.75
-6.96
-2.56
-4.39
-6.60
-9.89
-9.52
-9.45
3B
-2.20
-3.66
-4.76
-6.59
-6.95
-5.49
-6.23
-7.69
-
4A
-2.19
-3.30
-4.40
-4.76
-6.96
-4.40
-5.86
-8.42
-9.16
-8.79
-8.89
4B
-3.29
-2.93
-4.03
-5.49
-7.69
-4.03
-4.40
-7.32
-
[5] CHRÁSTOVÁ, V, BORSIG, E. Makromolekulová chémia. STU
Bratislava; 1996
[6] LOADMAN, M.J.R. Analysis of Rubber and Rubber-like
Polymers. Dordrecht, Kluwer Academic Publisher, 1999
[7] FRANTA, I. a kol. Zpracování kaučukových směsí a vlastnosti
pryže. Praha, STNL, 1969
[8] BARLOW, F. Rubber Compounding - Principles, Materials and
Techniques (Second Edition). New York, Marcel Dekker, 1993.
[9] MEISSNER, B, ZILVAR, V. Fyzika polymerů. Praha, SNTL,
1987
[10] LAZAR
T.
Inovatívne
výstupy
z transformovaaného
experimentálneho pracoviska s malým prúdovým motorom.
Košice, Elfa, 2011. p. 348
Conclusions
[11] OLŠOVSKÝ, M. a kol. Vplyv obsahu biozložiek v zmesi
biopaliva MERO a leteckého petroleja na vlastnosti gumových
tesnení palivových sústav leteckých motorov. In: Zborník z 8.
medzinárodnej vedeckej konferencie Nové trendy rozvoja
letectva. Košice; 11. – 12. 9. 2008
Previous research on the impact of MERO in aviation
fuel showed that if the maximum amount of MERO was
up to 30 wt. %, the degradation of rubber parts ATCE in
aviation fuel was not observed [10 - 12]. During
operation, all the parts of ATCE are exposed to
significant temperature various changes and it has
noticeable influence on durability relating to utility
properties of all materials. Besides focusing on the
impact of MERO content in fuel, the attention was also
paid to observation of the changes of properties for
rubber seals at lower and higher temperature (+100 °C
and -20 °C) and it was connected with the more
[12] KRAJČI, J. Vplyv prídavku biopaliva na gumové tesnenia
leteckých motorov (diplomová práca). Púchov: FPT TnUAD;
2009, 59 s.
[13] DUBOVSKÝ, M. Vplyv prevádzkových podmienok na gumové
tesnenia palivových sústav s biopalivom (diplomová práca).
Púchov: FPT TnUAD; 2012, 66 s.
Review: prof. Ing. Darina Ondrušová, PhD.
doc. RNDr. Mariana Pajtášová, PhD.
15
Materiálové inženýrství
Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Hydrophobic CMS and its Usage in the Rubber Blend
Hydrofobizovaný KMŠ a jeho využitie v gumárenskej zmesi
doc. Ing. Iva Sroková, CSc., Ing. Jaroslava Janíčková, Ing. Ladislav Janek, Faculty of Industrial Technologies,
Trenčín University of Alexander Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia, RNDr. Vlasta
Sasinková, Institute of Chemistry, Center for Glycomics, Slovak Academy of Sciences, 845 38 Bratislava,
Slovakia, Mgr. Agáta Dujavová-Laurenčíková, PhD., Institute of Electrical Engineering, Slovak Academy of
Sciences, Dúbravská cesta 9, 841 04 Bratislava, Slovakia
This thesis deals with hydrophobization of carboxymethyl starch because the hydrophobization is closely connected
with the preparation of oleate carboxymethyl starch (OCMS) with DS = 2.5 and its used as vulcanisation reagent in
the tread blend based on natural rubber. FT-IR spectroscopy confirmed that esterification of CMS with oleoyl
chloride (OCH) at appropriately selected conditions can be used for preparation of ester - OCMS with a higher
degree of substitution (DS = 2.5). Thermogravimetric analysis (TGA) confirmed the assumption that higher DS
increases the thermal stability of oleate CMS in comparicon to the initial CMS. OCMS is used as vulcanization
reagent with the amount from 0.5 – 1.5 phr in the tread blend to partially replace traditionally used vulcanization
reagent (sulfur in an amount of 1.65 phr). The vulcanization characteristics are determined from the prepared
blends and the samples for the evaluation of mechanical properties of vulcanizates are prepared. In the future,
prepared OCMS could be applied as vulcanization reagent in a suitably chosen vulcanization system.
Táto práca sa zaoberá hydrofobizáciou karboxymetylškrobu, ktorá vedie k príprave oleátu karboxymetylškrobu
(OKMŠ) s DS = 2,5 a jeho využitím vo funkcii vulkanizačného činidla v behúňovej zmesi na báze prírodného
kaučuku. FT-IR spektroskopiou sa potvrdilo, že esterifikáciou KMŠ s oleoyl chloridom (OCH) pri vhodne zvolených
podmienkach sa pripraví ester - OKMŠ s vyšším stupňom substitúcie (DS = 2,5). Termogravimetrická analýza
(TGA) potvrdila predpoklad, že vyšší DS zvyšuje termickú stabilitu oleátu KMŠ v porovnaní s východiskovým KMS.
V behúňovej zmesi sa použil OKMŠ v množstve 0,5 – 1,5 dsk, vo funkcii vulkanizačného činidla s cieľom čiastočne
nahradiť tradične používané vulkanizačné činidlo (síra v množstve 1,65 dsk). Z pripravených zmesí sa stanovili ich
vulkanizačné charakteristiky a z vulkanizátov sa pripravili vzorky pre hodnotenie mechanických vlastností. Zistilo
sa, že použitie OKMŠ ako čiastočná náhrada tradične používaného vulkanizačného činidla ovplyvňuje vulkanizačné
charakteristiky ako aj mechanické vlastnosti. Vulkanizačný proces prebehol, ale hodnoty koeficientu rýchlosti
vulkanizácie (Rv) sa znížili. Naopak, hodnoty optimálneho času vulkanizácie t(c90) sa zvýšili. Mechanické vlastnosti
vulkanizátov (pevnosť v ťahu pri pretrhnutí a ťažnosť), kde sa OKMŠ použil boli podstatne lepšie do obsahu 1 dsk
v porovnaní so štandardnou behúňovou zmesou aj napriek poklesu sieťovej hustoty. Pripravený OKMŠ by
v budúcnosti mohol nájsť uplatnenie aj ako potenciálne vulkanizačné činidlo pri vhodne zvolenom
vulkanizačnom systéme.
Many literature studies describe the application of
polysaccharides and many other biopolymers which are
obtained from the renewable sources. These mentioned
polysacharides and biopolymers can be used as
additives into rubber blends. This fact is closely
connected with their biodegradability to the natural
ecosystems and it also leads to reduction of cost relating
to rubber products. The starch is the cheapest and the
second one wide spread polysaccharide but there are
some limiting factors which cause that it is difficult to
use it as an additive. Due to the enormous number of
hydroxyl groups in the macromolecule of starch it
belongs to hydrophilic polymers as well as its particles
are really large (1000 – 5000 nm). All these mentioned
facts are the reason of insufficient mechanical properties
in the rubber blends filled by starch. Therefore there is
some effort to plasticize the starch and it leads to
reduction of particle size or the given starch could be
even modified to obtain the hydrophobic character or
combination of both these procedures is another
possible solution. Quite interesting modification has
been introduced by Wang et al. [3] where the
esterification can be used for modification of particles.
This esterification was used for preparation of starch
xantate where the size of particles was about 200 nm.
Subsequently, they used the modified starch into the
blends on the basis of the natural rubber (NR) where all
its particles were dispersed homogeneously in the whole
matrix of NR. There was the significant increase of the
thermal stability and better mechanical properties were
observed for blends which contained this modified
starch with its amount up to 20 phr. Modification as
well as utilisation of starch as filler is presented by
Valodkar a Thakore [7, 8] who modified the corn starch
to prepare the starch nanoparticles. Moreover, these
nanoparticles were disperged into the blend when the
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ISSN 0018-8069
Materiálové inženýrství
Material Engineering
methylene bands (2922 cm-1 and 2852 cm-1) and there is
also reduction of bands corresponding to hydroxyl
groups at wave numbers ~ 3305 cm-1. The addition of
substituent - the rest of oleic acid in macromolecules of
CMS leads to gradual increase of thermal stability of
derivatives and it is connected with increasing DS and
in this specific case, the initial decomposition
temperature (Ton1) is 324 °C and the beginning of the
final decomposition temperature (Ton2) is 392 °C.
amount was up to 30 phr and it is closely connected
with better mechanical as well as thermal properties.
This work is focused on the hydrophobization of CMS
with oleoyl chloride and prepared OCMS with DS = 2.5
was utilized as an vulcanization reagent for tread
rubber blends which could gain the specific properties
by this way.
Experiment
During the preparation of tread blends, amount of
OCMS as vulcanization reagent was 0.5, 1, 1.5 phr. The
given mentioned CMS oleate influenced almost all of
the basic vulcanizated parameters. Vulcanization
process was carried out but the values of vulcanization
rate coefficient (Rv) were reduced and the values of
optimum time of vulcanisation t(c90) were increased in
comparison to standard blend.
O-(carboxymethyl)starch (CMS) with DS = 0.3 was
obtained from Friedrich – Schiller – University (Jena,
Germany). Oleoyl chloride (C18H33COCl) was from
Sigma – Aldrich Chemie (Steinheim, Germany). Natural
rubber (SMR-20) – (Malajzia) and carbon black of type
N 121 – producer DGW (Dortmund, Germany).
Methods
Mechanical Properties and network density
FT-IR spectra were measured on spectrophotometer
NICOLET 6700 by ATR Smart Orbit technique
operating at 4 cm-1 resolution and the number of scans
128. TG analysis was performed using a Mettler-Toledo
TGA/SDTA 851e instrument in a nitrogen atmosphere
(30 ml/min) at heating rate of 10 °C/min in a
temperature range from 20 up to 550 °C. Vulcanization
curves for prepared blends were measured by the device
RHEOMETER 100 MONSANTO at 150 °C at Faculty
of Industrial Technologies in Puchov according to STN
62 1416. Mechanical properties of prepared
vulcanizates were evaluated by measuring the tensile
tear strength, and elongation on testing machine
Shopper at room temperature 25 °C while the strain rate
was 50 mm/min. according to STN 62 1436.
The results relating to selected physical and mechanical
properties confirmed the slight increase of tensile tear
strength except for the blend with the highest phr as
well as increase of elongation for treads blends in
comparison to standard blend. The highest value of the
elongation (558 %) was obtained by the tread blend
with 1.5 phr of OCMS in comparison to standard blend.
On the contrary, the values of hardness for blends with
increasing content of OCMS have the slight decreasing
tendency. This decreasing tendency is probably
connected with increasing values for elongation in
relation to increasing amount of OCMS (tab. 2).
Network density for all prepared vulcanizates with
OCMS has the steep decreasing tendency when the
amount of OCMS is increased.
Esterification of CMS with oleoyl chloride (OCH) by
conventional heating
Tab. 1 Tensile, elongation and hardness of tread blends with various
content of OCMS
Tab. 1 Pevnosť, ťažnosť a tvrdosť behúňových zmesí s rôznym
obsahom OKMŠ
OCMS with DS = 2.5 was prepared by conventional
esterification method of CMS with oleoyl chloride
(OCH) in the mass ratio of 1 : 4 and reaction time was
12 h and the procedure is described in ref. [4].
Tensile
(MPa)
25.7
Elongation
(%)
499
Hardness
(IRHD)
70
OCMS – 0.5 phr
33.3
512
67
OCMS – 1 phr
31.1
555
64
OCMS – 1.5 phr
18.8
558
61
Sample
Preparation of rubber blends
STANDARD
Rubber blends were prepared in a laboratory blender of
type BRABENDER where the chamber had a volume of
70 cm3 and the constant number of revolutions was 50
rpm / min. Subsequently, these blends were
homogenized and pressed by two rollers in laboratory.
The exact prescription can not be introduced in this
contribution due to preservation of firm trade secret.
Tab. 2 Network density of tread blends with various content of OCMS
Tab. 2 Sieťová hustota behúňových zmesí s rôznym obsahom OKMŠ
Sample
Results and discussion
Standard
0.5 phr
1 phr
1.5 phr
1.37
0.87
0.68
0.17
-4
ν 10
(mol/cm3)
ν – network density of tread blends
OCMS with DS = 2.5 was prepared at appropriately
selected reaction conditions and environment. FT-IR
spectra confirm the increase of the ester band at 1738
cm-1 as well as increase of band corresponding to
The rearrangement of formed polysulfidic bonds to
monosulfidic and disulfidic forms can occur because
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Materiálové inženýrství
Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
they are much stronger than those polysulfidic and it is
caused by reversion during the vulcanization process of
blends when the amount of OCMS5 is 0.5 and 1 phr.
According to the mentioned facts, it could be concluded
that formed network is stronger although the number of
crosslink bonds is lower. The decrease of the network
density, tensile tear strength as well as hardness is
caused by higher doses of OCMS with its amount
1.5 phr. Behaviour of OCMS in the blend can be
specified as behaviour of plasticizer and it is even
confirmed by the higher values of elongation and the
lower values of hardness in comparison with the
standard blend.
Acknowledgement
This work has been supported by project SK-PL0044/09, VEGA grant No. 1/0006/12, VEGA grant
No. 2/0062/09 and project APVV SUSPP-0006/09
Literature
[1] WANG, Z.F., PENG, Z., LI, D.S., LIN, H., ZHANG, K.X., SHE,
X.D., FU, X. The impact of esterification on the properties of
starch/natural rubber composite. Composites Science and
Technology, 2009, 69, p. 1797-1803
[2] VALODKAR M., THAKORE, S. Organically modified nanosized
starch derivatives as excellent reinforcing agents for
bionanocomposites. Carbohydrate Polymers, 2011, 86, p. 12441251
Conclusions
[3] VALODKAR, M., THAKORE, S. Isocyanate crosslinked reactive
starch nanoparticles for thermo-responsive conducting
applications.
Carbohydrate Research, 2010, 345, p. 2354-2360
The utilisation of CMS oleate with DS = 2.5 in rubber
blends as the vulcanization reagent, the content of
which is (0.5 – 1.5 dsk), confirmed that there is the
influence on some mechanical properties (tensile tear
strength, elongation) as well as vulcanization
characteristics although there are the low amounts. In
the future, the hydrophobized derivatives of CMS with
the high DS could be also applied in the rubber industry
[4] JANÍČKOVÁ,
J.,
SROKOVÁ,
I.,
PAGACZ,
J.,
CHROMČÍKOVÁ, M., PIELICHOWSKI, K. Preparation,
Characterization and Properties of HEC/CMS – esters Blends. In
Machine, Modeling and Simulations, Vrátna / Slovakia, 2011,
p. 299-304, ISBN 978-80-8075-494-5
Review: prof. Ing. Darina Ondrušová, PhD.
prof. Ing. Tatiana Liptáková, PhD.
_____________________________________________________________________________________
18
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ISSN 0018-8069
Materiálo vé inženýrství
Material Engineering
The Embrittlement of Small Steel Components which are Heat Treated in
Continuous Links
Krehnutie malých oceľových súčiastok pri ich tepelnom spracovaní
v kontinuálnych linkách
doc. RNDr. Ján Bezecný, CSc., Ing. Robert Vavrík, Faculty of Industrial Technologies, University of Alexander
Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia
The reliability together with the lifetime is important in the case of components which are used as the transport
means. These mention requirements relating to transport devices are often not fulfilled because of material
embrittlement by no optimum heat treatment (overheating), by rising of austenite grains and its embrittlement in
consequence of increased quenching temperatures and long heating time. Parts which have small dimensions are
very sensitive to the overheating and it is especially connected with the case of mass heat treatment in continuous
links. According to the obtained experimental data we were able to conclude that the modification of regime of heat
treatment (TG I, TG II) markedly improve the brittle fracture properties on contrary to the original damaged pins.
Both new regimes led to the austenite grain refinement from 30 µm to 20 µm and moreover, there was the ratio
decrease of intercrystalline facets form 100% to approximately 40%.
U súčiastok dopravnej techniky je veľmi dôležitá ich spoľahlivosť a dlhá životnosť. Častou príčinou nesplnenia
týchto požiadaviek je skrehnutie materiálu pri neoptimálnom tepelnom spracovaní (prehriatí), spojenom s rastom
austenitických zŕn a ich krehnutím v dôsledku zvýšených kaliacich teplôt a dlhých dobách ohrevu. Veľmi citlivé na
prehriatie sú súčiastky malých rozmerov, hlavne v prípade ich hromadného tepelného spracovania v kontinuálnych
linkách. Preto je nevyhnutné optimalizovať podmienky tepelného spracovania vzhľadom na konkrétnu pec, v ktorej
sa súčiastky tepelne spracovávajú. Hodnotenie mikromorfológie lomových plôch je efektívnou metódou kontroly
kvality tepelného spracovania. Úpravou režimu tepelného spracovania sme dosiahly podstatné zlepšenie
krehkolomových vlastností. Z nameraných výsledkov vyplynulo, že oproti pôvodným havarovaným čapom sa oboma
novými režimami TS I a TS II výrazne zlepšili krehkolomové vlastnosti, čoho prejavom bolo zjemnenie
austenitických zŕn z 30 µm na 20 µm a zníženie podielu interkryštalických faziet zo 100% na cca 40%. Napriek
tomuto zlepšeniu však nebol dosiahnutý úplne optimálny húževnatý stav. Nárast podielu IKŠ lomu po popúšťaní
svedčí o rozvoji popúšťacej krehkosti, prispievajúcej ku zvýšeniu krehkosti ocele 12 071.
The draft of optimum regime for the heat treatment of
small components is technologically demanding problem
over the world. The problems are mainly created by their
mass replacement in continuous links, when the optimum
parameter choosing does not depend on type of material
and dimensions of components. The achievement of
required tensile and brittle fracture properties can be
carried out by help of any refinement. The optimum
regime anomalies of heat treatment may lead to spurious
material embrittlement during refinement process and can
make impossible the safe function of components [1].
Extra hazardous is fact when components are parts of
complicated construction equipments which are
practically in all armament systems. Only one small
broken component can cause that the whole equipment
can not be used and it means that this all component is
out of order. From the practical example, we can use the
– chain pin which is a component of driving chain.
material embrittlement by heat treatment. Analyzed
chain pins were made of 12 071 material. The diameter of
specimen is 5.3 – 0.02 mm a length of 18.2 – 0.1 mm.
The prescribe hardness after the quenching is HV 5 =
620, with a permissible deviations of +80, -50 HV.
Material 12 071 is the noble carbon steel determined for
refinement and it is hardenable in water, oil but it
depends on component size and shape. The chemical
content is introduced in tab. 1.
Tab. 1 Chemical content of material 12 071
Tab. 1 Chemické zloženie materiálu 12 071
Element
Chemical
content [%]
C
0.60 0.70
Mn
0.60 0.80
Si
max.
0.35
P
max.
0.04
S
max.
0.04
In terms of drawing documentation are chain pins
refinements with their final hardness 620 HV. Whole
process of hardening and tempering is realized in fully
automatic continuous furnace. Control of belt speed can
help us to determine heating conditions relating to
hardening temperature and holding time relating to
austeniting temperature. Oil was used as a hardening
medium. Then the chain pins are tempered in tempering
Experimental material and testing results
The experimental materials consist of chain pins of the
driving chains which cracked during the traffic and
laboratory lifetime exams. Main reason was hidden in the
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Materiálové inženýrství
Material Engineering
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ISSN 0018-8069
The size of ICC facets [mm]
- The temperature tendency in furnace is fluent and
relatively gradual.
- Maximum austenite temperature was 848.30 °C.
- The hardening temperature was 832.60 °C.
- The batch size is characterized by furnace performance
which was 225 kg/hour.
- Batch was tempered in oval tempering furnace at
temperature of 260 °C and time duration was 1 hour.
0,045
Veľkosť IKŠ faziet [mm]
furnace. Specific conditions of heat treatment for the
ruptured chain pins were not provided.
The analysis of the reasons relating to the early rupture of
the chain pins was estimated on the basis of the common
in-service conditions:
- Hardness measured in the core of samples has values of
54 HRC.
- Microstructure of samples is created by coarse, high
tempering martensite.
- According to the visual evaluation, all the fractures –
working and laboratory – are glossy, crystalline and
they does not have any character of macroplastic
deformation, fig. 1.
- Micromorphology of working fractures of the both
samples was evaluated by SEM and brittle
intercrystalline cleavage micromechanism of rupture
(ICC) was observed prdominantly and the
intercrystalline facets size was 30 µm.
- Primary technological reason of low lifetime of the
chain pins was connected with material embrittlement
by heat treatment [2].
0,04
0,035
0,03
0,025
0,02
0,015
0,01
0,005
0
0
10
20
30
40
50
60
70
80
90 100 110
Výdrž
kaliacej temperature
teplote [min] [min]
Holding time
on na
hardening
Fig. 2 Dependency of the intercrystalline cleavage (ICC) facets size
versus holding time of hardening temperature the 42CrMo4
material [3]
Obr. 2 Závislosť veľkosti IKŠ faziet ocele 42CrMo4 na čase výdrže
na kaliacej teplote [3]
Hardness measurement
The hardness measurement was estimated with HRC
method by loading of 1471N. The hardness of 65. 5 HRC
was measured after hardening; the hardness of 57 HRC
was estimated after the hardening and tempering. By all
samples was occurred the hardness decrease by cca 6
HRC. The final hardness of 57 HRC equals to 650 HV
and therefore the hardness of component is acceptable in
relation to drawing documentation.
Fig. 1 Intercrystalline cleavage (ICC) fracture
Obr. 1 IKŠ lom
In relation to some materials, especially in the thin-walled
components, there is the occurrence of significant grain
growing with increasing hardening temperature as well as
with holding time on the hardening temperature. For
components which are made of 42CrMo4 it was proved
that grain size growth in dependency on holding time at
specific temperature and the whole holding time of
components in the furnace did not exceed 30 minutes [3].
The average grain size should not be higher than
0.024 mm for given material and it refers to stage 8, fig. 2.
The micrographic fracture properties of steel were
evaluated as unacceptable when the holding time was 50
minutes. According to the findings, the determination of
the heat treatment regime is necessary to optimize because
of achievement of better brittle fracture properties – the
presence of brittle intercrystalline facets decreases to
minimum and the producer put the temperature measuring
probes into hardening furnace (in concrete zones of
furnace). The aim was to decrease the highest austenite
temperature and holding time in opposite to the previous
regime of heat treatment. The applied regime was
signified as TG I.
From recorded course of temperatures in real furnace we
can conclude:
- total time of heating at hardening temperature was
40 minutes;
- the austenite temperature of 820 °C was overcome for
14 minutes in relation to the batch.
Microstructure evaluation
Microstructure of the hardened but non-tempered sample
and non tempering state of sample is uniformly coarsegrained, needle and it is created by martensite and
residual austenite. The martensite needles are relatively
strong, the residual austenite creates bright „islands“
between the martensite needles. Microstructure of the
hardened and tempered sample is uniformly, relatively
coarse – grained, needle, created by low tempering
martensite and residual austenite. The martensite needles
are less strong; however the residual austenite is observed
among the tempering martensite needles.
Fractographic analysis
The laboratory fractures were prepared for fractographic
analysis. The ruptured pins were analyzed after hardening
procedure and after the combination of hardening and
tempering procedure. The fracture of the hardened
sample was soft crystalline, plane and without any
macroplastic deformation. Micromorphology of fracture
area in hardening and non tempering state is created by
mixed transcrystaline quasicleavage (TCQ) and low
energy transcrystaline dimple (TCD) and ICC fracture
where the size of intercrystalline facets was 20 µm.
Surface of intercrystalline facets is mostly smooth
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ISSN 0018-8069
Materiálo vé inženýrství
Material Engineering
From these results we can conclude that in relation to
hardened samples, there was the occurrence of partial
weakness of grain boundaries as well as material
embrittlement and it is connected with presence of the IC
facets. For hardened and tempered samples, the
micromorphology changes to the mixed ICC and TCD,
fig. 6. The size of ICC facets, which correspond to
austenite grains, is fixed, but their ratio is higher and it is
analogous toregime TG I.
without the macroplastic deformation features, fig. 3. The
fracture of hardened and tempered sample shows the
fluctuation of micromorphology to mixed transcrystaline
dimple and intercrystalline cleavage, fig. 4. The size of
ICC facets which refers to initial austenite grains is
practically fixed, but their ratio is larger.
Fig. 3 TCQ+TCD+ICC fracture
Obr. 3 TKQ+TKJ+IKŠ lom
Fig. 4 TCD+ICC fracture
Obr. 4 TKJ+IKŠ lom
The cases of pins rupture have been still observed
although the heat treatment was modified and it led to
creation of regime (TG II) where the belt speed was
increased. Main differences were in:
- Reduction of the whole time of heating from 40 to 30
minutes
- Modification of the whole holding over the 820 °C
from 14 to 10 minutes
- Decreasing the maximum austenite temperature from
848.10°C on 836.70 °C
Fig. 5 TCQ+ICC+TCD fracture
Obr. 5 TKQ+ IKŠ+TKJ lom
Fig. 6 ICC+TCD+ fracture
Obr. 6 IKŠ+TKJ lom
Conclusions
The measure experimental data show that the modified
regime (TG I, TG II) can markedly improve the brittle
fracture properties. Moreover, we achieved the austenite
grain refinement from 30 µm to 20 µm and ratio relating
to intercrystalline facets decreased form 100% to
approximately 40% but the toughness was not in
optimum. The intercrystalline cleavage fracture ratio
increasing after the tempering process gives evidence
about the development of tempering brittleness expansion
and it contributes to steel brittleness rising. It depends on
producer whether if the link parameters for heat treatment
can be used for decrease of austenitizing temperature or
they can be used for decrease of holding time at this
temperature while the prescribed hardness is preserved. It
is also necessary to solve the problem relating to cooling
of pins after tempering. There is the proposal that the
higher attention must be paid to heat treatment as well as
to all thin-walled parts in general.
Hardness measurement – TG II
The measurement was realized in the same way as TS.
Hardened samples exhibited 65 HRC while and hardened
tempered samples exhibited 57 HRC. During the
tempering the decrease of hardness by 6 HRC was
observed.
Microstructure evaluation - TG II
Microstructure of hardened sample is uniform, needle,
created by martensite and residual austenite. Martensite
needles are quite strong, residual austenite creates the
bright „islands“between the martensite needles. The
microstructure of samples which were hardened and
tempered was uniform, needle, created by low tempered
martensite and residual austenite.
Literature
[1] KOUTSKY, J., JANDOŠ, F., KAREL, V. Lomy oceľových častí.
SNTL, Praha, 1976
[2] DUTKOVÁ, K. Metalografická analýza a stanovenie príčiny
zlomenia detailu čap, DP. Trenčianska univerzita A. Dubčeka
v Trenčíne, 2010
Fractographic analysis - TG II
The fracture of hardened samples is soft, crystalline,
plane, without significant macroplastic deformation. The
fracture area of he hardened and tempered samples is
more relief and the macroplastic deformations are
significant. Micromorphology of fracture for hardened
and tempered sample is created by mixed TCQ, low
energy TCD and ICC fracture while the size of IC facets
is 20 µm. The surface of IC facets is mostly smooth
without some marks of microplastic deformation, fig. 5.
[3] BEZECNÝ, J. Vznik trhlín a lomov pri tepelnom spracovaní
ocelí, Trenčianska univerzita A. Dubčeka v Trenčíne, ISBN: 97880-8075-202-6, 2007
[4] HAZLINGER, M. et al. Degradačné procesy a predikcia životnosti
materiálov. STU Bratislava, 2010. ISBN 978-80-227-3334-2
Review: prof. Ing. Františka Pešlová, PhD.
prof. Ing. Tatiana Liptáková, PhD.
21
Materiálové inženýrství
Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Polymer Blends Based on Styrene-Butadiene Rubber
Polymérne zmesi na báze styrén-butadiénoveho kaučuku
doc. Ing. Iva Sroková, CSc., Ing. Ladislav Janek, Ing. Jaroslava Janíčková, Faculty of Industrial Technologies,
Trenčín University of Alexander Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia, Ing. Mária
Chromčíková, Vitrum Laugaricio – Joint Glass Centre of the Inst. of Inorg. Chem., SAS Bratislava and Trenčin
University of Alexander Dubček in Trenčín, 911 50 Trenčín, Slovakia, RNDr. Vlasta Sasinková, Institute of
Chemistry, Center for Glycomics, Slovak Academy of Sciences, 845 38 Bratislava, Slovakia
Organically modified MMT (Nanofil 2, Nanofil 5) were used as the nano-fillers for the preparation of the styrenebutadiene rubber (SBR) blends. The starch oleates were used in the function of compatibilizer. Some better
dispersion of the fillers in the rubber matrix can be achieved through the compatibilizer. The mechanical properties
of the prepared blends were evaluated using classical methods. These properties of the SBR blends filled with
organically modified MMT and starch oleate have been comparable to the blends which were filled with traditional
fillers - carbon black. Curing characteristics of the rubber mixture filled with inorganic nano-fillers and with starch
oleates used in the function of plasticizer or compatibilizer showed positive effect on the optimum cure time.
According to the results relating to mechanical properties, it is clear that a mixture of each one of two tested types
of nano-filler has higher or comparable properties to the standard rubber mixture. In addition, the mechnical
properties were better in the all cases relating to 1-5 wt. % of starch oleates.
Táto práca je zameraná na štúdium vulkanizačných a mechanických vlastnosti polymérnych zmesi na baze styrénbutadiénového kaučuku. Ako náhrada za uhlíkové sadze do týchto zmesi sa použili organicky modifikovane formy
vrstevnatého ílu (Nanofil 2, Nanofil 5) s kombináciou oleátu škrobu S-O. Organicky modifikovane tipy plnív na baze
monmorilonitu sú od firmy Sud Chemie. Oleát škrobu sa použil v zmesi SBR vo funkcii plastifikátora pripadne
kompatibilizatora. Prostredníctvom kompatibilizatora možno dosiahnuť lepšie rozptýlenie plniva v kaučukovej
matrici. Z týchto zmesí sa stanovili ich vulkanizačné charakteristiky z vulkanizátov sa pripravili vzorky pre
hodnotenie mechanických vlastností Mechanické vlastnosti pripravených SBR zmesi plnené ekologicky
modifikovanou formou MMT a oleátu škrobu sa hodnotili podľa STN 62 1436 a porovnali sa so štandardnou
vzorkou plnenou bežnými sadzami. Z výsledkov hodnotenia mechanických vlastnosti je jasne vidieť že obidva druhy
vrstevnatých ílov sú schopne čiastočné nahradiť klasické gumarenské sadze ako plnivo. Z vulkanizacných
charakteristík vyplýva, že oleát škrobu v kombinácii s vrstevnatými ílmi má schopnosť znižovať optimálny čas
vulkanizácie, čo môže mať napokon priaznivý vplyv na šetrenie elektrickou energiou.
Utilization of montmorillonite (bentonite type) in
natural rubber and styrene – butadiene rubber was tested
and studied in [1]. Improvement of mechanical
properties, thermal stability as well as barrier properties
was discovered during testing. The disadvantage of
these layered clays is their hydrophilic character which
causes more difficult disperse to the hydrophobic rubber
matrix. Therefore, it is necessary to modify the fillers
and change the hydrophilic character of MMT to
hydrophobic [2]. Subsequently renewable resources
(corn, starch and lignin) were used as additives to the
preparation of rubber blends based on natural and
styrene butadiene rubber. The effect of these
polysaccharides on curing characteristics, physicalmechanical properties and dynamical-mechanical
properties was studied and compared to the blends with
SiO2 as fillers. The results confirmed that biopolymers
can be used as modifiers to the polymeric rubber blends
[3, 4]. This paper presents the preparation and properties
of the styrene-butadiene rubber (SBR) blends using
organically modified MMT nano fillers (Nanofil 2,
Nanofil 5) and starch oleate as
compatibilizers.
modifiers or
Experiment
Styrene - Butadiene Rubber, Kralex SBR 1500, from
Kralupy (Czech Republic) was used as a matrix. Starch
oleates (S-O) were prepared as it is described in [5] and
they were applied as fillers or compatibilizers. Nanofil 2
and Nanofil 5 were employed as inorganic fillers from
Süd Chemie (Germany). Carbon black (CB) was used as
the commercial filler and it was from Chezacarb Aconducting (Czech Republic).
Methods
Mechanical properties of the prepared blends (tensile
strength, tensibility and hardness) were measured at
room temperature using Monsanto 100 testing machine.
The hardness of vulcanized rubber was determined at
room temperature by a hardness tester IRHD.
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ISSN 0018-8069
Materiálové inženýrství
Material Engineering
of rubber mixtures is reduced and it means that the
compatibilizer S-O affected curing characteristics.
Preparation of the rubber blends
Blends were prepared using Plasti - Corder Brabender
(volume 75 cm3), with constant 50 rpm/min, at
temperature 110 °C in step I and at 100 °C in step II.
Tab. 2 Cure characteristics of SBR blends with nanofillers and
compatibilizer S-O (1% and 5%)
Tab. 2 Vulkanizačné charakteristiky SBR zmesi s nanoplnivom
a kompatibilizátorom S-O (1% a 5%)
Specified vulcanization conditions were 150 °C, 20 MPa
(time depends on reometer curve). Composition of the
classical rubber blends is given in tab. 1.
Tab. 1 Composition of the classical rubber mixture
Tab. 1 Zloženie gumárenskej zmesi
rubber KRALEX SBR 1500
Content in the
mixture [phr]a
100
ZnO
5
stearin - Conti flake
2
sulfur 1% (milling oiled)
2
Component
CBSb accelerator
1
Filler (CB, Nanofil2, Nanofil5)
25
rapeseed oil NKOc
5
5%N2
Min.
torque,
Mmin [Nm]
1%
5%
25.7
27.0
Max.
torque,
Mmax [Nm]
1%
5%
70.8
71.0
Extent of
cure,
M [Nm]
1%
5%
45.1
44.0
Optimum
cure time,
t90 [min]
1%
5%
26.5
25.0
10%N2
28.5
24.5
80.0
67.5
51.5
43.0
27.5
21.5
15%N2
24.0
23.2
68.5
68.5
44.5
45.3
20.5
19.5
5%N5
24.8
27.0
72.0
72.0
47.2
45.0
27.0
25.0
10%N5
27.0
25.0
74.0
71.0
47.0
46.0
22.5
20.5
15%N5
24.0
21.0
68.5
65.0
44.5
44.0
20.5
Samples
32.5
100%CB
91
58.5
16.0
37.5
N2 – Nanofil 2, N5 – Nanofil 5
Mechanical properties of blends
Classical mechanical properties (the tensile strength at
break and tensibility) of the prepared rubber blends
provide general information on the material properties
of rubber mixture. These properties are very important
for each polymer blend and they were evaluated
according to STN 62 1436. Results of these properties
for SBR / Nanofil / SO blends are summarized in tab. 3.
a
Parts hundred parts of rubber), b N-cyclohexyl-2-benzothiazyl sulphenamide
c
Oil fraction from hydrocracking of vacuum distillate of petroleum
Glycerol (GL) acting as plasticizer (20 %) [6] as well as
starch oleate (S-O) in function of compatibilizer (1% or
5%) have been added mechanically into model rubber
mixture during first stage of the mixing.
Tab. 3 Mechanical properties and hardness of the SBR blends with
the various content of nano-fillers (5-15%) and starch oleate
(1-5 %)
Tab. 3 Mechanické vlastnosti a tvrdosť SBR zmesí s rôznym
obsahom nanoplnív (5-15%) a oleátu škrobu (1-5%)
Results and discussion
Organically modified Montmorillonite (Nanofil 2,
Nanofil 5) used as nano-fillers together with
commercial filler carbon black were employed to the
preparation of the Styrene - Butadiene Rubber (SBR)
blends. Starch oleates (S-O) were prepared and applied
as modifiers of fillers to polymeric mixture because they
could improve the compatibility between the filler and
rubber.
Samples with S-oleate
(1 and 5 %) as
compatibilizer
1%
5%
Cure characteristics
Tensile
strenght
[MPa]
1%
5%
Tensibility
[%]
Hardness
[IRHD]
1%
5%
1%
5%
5%N2
D1-1
D1-5
19
20
386
397
75
74
10%N2
D2-1
D2-5
20
19
356
431
75
72
15%N2
D3-1
D3-5
21
18
411
412
74
73
5%N5
E1-1
E1-5
19
20
340
403
76
74
10%N5
E2-1
E2-5
19
17
397
373
70
72
15%N5
E3-1
E3-5
13
17
363
402
73
100%CB (standard)
22
365
70
75
N2 – Nanofil 2, N5 – Nanofil 5
Curing characteristics of the prepared blends with nanofillers and with oleates of starch were determined
according to STN 62 1431 and they are given in tab. 2.
As can be seen from tab. 3, blending two types of nanofillers (Nanofil 2, Nanofil 5) and starch oleate show
higher or comparable properties to the classical rubber
mixture used as standard filler with 100% of carbon
black. The tensibility of the prepared blends compared
to standards increased in all samples with S-O as
a compatibilizer. The hardness estimated according to
STN 62 1431 was comparable to the standard blend
or lower.
In comparison to CB, torque Mmin decreased with
increasing nano-fillers content for all samples including
starch oleate (S-O) as a compatibilizer. The reduction of
torque Mmin was observed for a sample containing 15%
of nano-fillers and compatibilizer S-O. Torque Mmin is
proportional to the viscosity of the rubber mixture
heated at cure temperature and this temperature
characterized its stiffness. Maximum torque M max
showed that increasing content of inorganic filler
increased the shear modulus of the rubber blends.
Maximum torque Mmax characterizes stiffness of rubber
at the end of the vulcanization process. Lower values of
Mmax refer to lower stiffness as well as viscosity of the
mixture at the end of the cure. The optimum cure time
Conclusions
SBR rubber blends filled with nano-fillers, namely
organically modified MMT (Nano 2, Nano 5) in an
amount of 5 – 15 wt. %, and starch oleate modifiers
(1 and 5 wt. %) were prepared and their mechanical
properties were evaluated.
23
Materiálové inženýrství
Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Curing characteristics of the rubber mixture filled with
inorganic nano-fillers and with starch oleates used in the
function of plasticizer or compatibilizer showed positive
effect on the optimum cure time.
[2] LACKO, M., ĎURFINOVÁ, J., POČAROVSKÝ, P.,
JURČIOVÁ, J., MACHO, M. Influence of interphase based on
isocyanates at starch surface and observing the application in
vulcanizates. In Sborník vědeckých prací Vysoké školy báňské –
Technické univerzity Ostrava, 2009, ročník LII, řada hutnická,
číslo 1, p. 94–97
From the results of mechanical properties, it is clear that
the mixture of each of tested two types of nano-filler has
higher or comparable properties to the standard rubber
mixture. These mechanical properties were better in the
all cases relating to 1 – 5 wt. % of starch oleates as
compatibilizer.
[3] ALEXY, P., FERANC, J., KRAMÁROVÁ, Z., HAJŠOVÁ, M.,
ĎURAČKA, M., MOŠKOVÁ, D., CHODÁK, I., ILISCH, S.
Application of lignins in rubber compounds, KGK Kautschuk
Gummi Kunststoffe, 2008, 61 (1-2), p. 26–32
[4] KRAMÁROVÁ, Z., ALEXY, P., CHODÁK, I., ŠPIRK, E.,
HUDEC, B., GREGOROVÁ, A., ŠÚRI, P., FERANC, J., BUGAJ,
P., ĎURAČKA, M.: Biopolymers as fillers for rubber blends,
Polymers for Advanced Technologies 2007, 18 (2), p. 135–140
Acknowledgement
This work has been supported by project SK-PL0044/09, VEGA grant No. 1/0006/12, VEGA grant No.
2/0062/09 and project APVV SUSPP-0006/09.
[5] KEBÍSKOVÁ,
J.,
SROKOVÁ,
I.,
JANEK,
L.,
CHROMČÍKOVÁ, M., CSOMOROVÁ, K.: Preparation,
Characterization and Properties of PLA/Starch Oleates Blends.
In Book of contribution on the 16th International Slovak – Polish
Conference „Maschine, Modeling and Simulations 2011”,
Sept.5-7, 2011, Terchová, Slovak Republic, p. 315–322, ISBN
978- 80-8075-494-5
Literature
[1] ZHENG, G., GUOJUN, S., WEISHENG, L., PEIYAO, L., LI, G.,
HAMHUA, L., XION, H. Preparation and properties of styrene
butadiene rubber / natural rubber / organo-bentonite
nacomposites prepared from latex dispersions, Applied Clay
Science, 2009, 46, p. 241–244
[6] ABURTO, A. Rheological and thermal properties of
thermoplastic starch with high glycerol content. Carbohydr.
Polym. 2005, 58, p.139–147
Review: prof. Ing. Darina Ondrušová, PhD.
prof. Ing. Tatiana Liptáková, PhD.
_____________________________________________________________________________________________
Vyostřený spor mezi ArcelorMittal a Paříží skončil dohodou
Česká televize, mav, ket
30.11.2012
Ocelárny ArcelorMittal nakonec vyřešily spor s francouzskou vládou o ztrátovou provozovnu ve Florange.
Firma sice dvě vysoké pece uzavřela, nyní ale slíbila další investice do ocelárny za 180 mil. eur (4,5 mld.
Kč). Díky investicím rozprostřeným do pěti let Florange nepřijde o žádná pracovní místa. Firma se tak
chce vyhnout zestátnění oceláren, kterým pohrozil francouzský prezident Francois Hollande v případě, že
firma pracovní místa nezachová. Vláda hrozila firmě, že pokud pece uzavře, převezme celou ocelárnu
pod svou správu. "Vláda se rozhodla nejít cestou dočasného zestátnění," řekl francouzský premiér JeanMarc Ayrault tři hodiny před stanovenou uzávěrkou jednání o Florange. "Žádné propouštění z důvodu
nadbytečnosti nenastane," dodal premiér.
ArcelorMittal potřeboval ve Florange uzavřít kvůli dlouhodobé nerentabilnosti dvě vysoké pece, které
zaměstnávají asi 600 lidí z celkového počtu 2 700 pracovníků hutě. Francouzský prezident chtěl pece
zachovat v provozu a hrozil, že pokud je firma nechá zavřít, vláda celou ocelárnu zestátní. Později ale
svá vyjádření zmírnil a říkal, že mu jde hlavně o pracovní místa.
Hrozby zestátnění posílily obavy investorů ze snahy socialistické vlády vměšovat se do podnikání. Záměr
znárodnit ocelárnu tento týden ostře kritizovali přední francouzští podnikatelé.
Francie má historicky nejvyšší nezaměstnanost a znárodnění by mohlo potkat i jiné firmy, které uvažují o
propouštění. Francie chce zachránit především pracovní místa. Ve Francii je bez práce nejvíce lidí za 13
let, a to přes tři miliony. Také proto už vláda nechce dalších 629 míst riskovat. Celý spor přitom znamená
ohrožení pro další podniky. Nevědí totiž, kde by se státní zásahy zastavily.
"Jestli jde o to vyvinout nějaký tlak, nebo vyhrožovat, je to absolutně neakceptovatelné. Je to skandál.
Znárodnění je zkrátka zabavení majetku," argumentuje šéfka federace francouzských zaměstnavatelů
Laurence Parisotová.
Jenže ArcelorMittal potřebuje rozsáhlé změny, protože ve 3. čtvrtletí 2012 celosvětově prodělal v
přepočtu skoro 14 mld. Kč. Působí mimo jiné i v České republice, kde v Ostravě provozuje největší
tuzemský hutní podnik.
SB
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ISSN 0018-8069
Materiálové inženýrství
Material Engineering
Influence of Electron Beam Irradiation on the Dynamic Mechanical
Properties of Non-vulcanized Styrene-butadiene Rubber Blend
Vplyv ožiarenia lúčom urýchlených elektrónov na dynamické mechanické
vlastnosti nevulkanizovanej styrén butadiénovej gumárenskej zmesi
doc. Mgr. Ivan Kopal, PhD., Ing. Karol Kováč, Ing. Mária Bačíková, University of Alexander Dubček in Trenčín,
Faculty of Industrial Technologies, I. Krasku 491/30, 020 01 Púchov, Slovakia, RNDr. Peter Hybler, PhD.,
Ing. Marko Fülöp, CSc., Slovak Medical University in Bratislava, University Centre of Electron Accelerators in
Trenčín, Ku Kyselke 497, 913 06 Trenčín, Slovakia, Ing. Vladimír Rusnák, VŠB-Technical University of Ostrava,
Faculty of Metalurgy and Materials Engineering, 17. listopadu 15, 708 33 Ostrava-Poruba, Czech Republic
The influence of electron beam irradiation on dynamic mechanical properties of non-vulcanized styrene-butadiene
rubber blend has been investigated in this paper. The blend was irradiated in air at room temperature by using
a 5 MeV electron beam accelerator with doses ranging from 0 to 300 kGy and with a maximum beam power of
5 W/m2. The dynamic mechanical analysis was performed by using a Perkin Elmer PYRIS Diamond Dynamic
Mechanical Analyzer in tension clamp mode with a temperature-time scan at a frequency of 0.5 Hz. Measurements
were carried out in a temperature range between 40 °C to 120 °C. It has been shown that the dynamic mechanical
properties of tested rubber blend strongly depend on the radiation dose. An increase in the radiation dose leads to
an increase of the temperature at which the vulcanization process of rubber blend begins.
Práca je venovaná štúdiu vplyvu ožiarenia nevulkanizovanej styrén butadiénovej gumárenskej zmesi elektrónovým
lúčom s vysokou energiou na jej dynamické mechanické vlastnosti. Vzorky vyšetrovanej gumárenskej zmesi boli
ožarované vo vzduchu, pri izbovej teplote, a to vysokoenergetickým lúčom elektrónov v 5MeV urýchľovači častíc
typu UELR 5-1C s maximálnym výkonom lúča 5 W/m2. Aplikované dávky žiarenia boli v intervale od 0 do 300 kGy.
Dynamická mechanická analýza testovacích vzoriek zmesi bola realizovaná analyzérom Perkin Elmer PYRIS
Diamond Dynamic Mechanical Analyzer v móde votknutej svorky, v režime registrácie teploty, ako aj času a pri
konštantnej frekvencii 0,5 Hz. Zisťované boli teplotné závislosti elastického, tiež stratového modulu a stratového
činiteľa pri rozličných dávkach žiarenia v teplotnom intervale od 40°C do 120°C. Dynamická mechanická analýza
nevulkanizovanej styrén butadiénovej gumárenskej zmesi ožiarenej elektrónovým lúčom s vysokou energiou ukázala,
že jej elastický modul, stratový modul, ako aj stratový činiteľ v teplotnom intervale kaučukovitého stavu silne závisia
od veľkosti dávky žiarenia. Dynamická mechanická analýza zároveň ukázala, že s rastúcou dávkou žiarenia rastie aj
teplota začiatku procesu jej vulkanizácie.
The properties of polymers can be tuned for specific use
by various techniques [1 – 4]. In recent years, several
new approaches, such as plasma etching or irradiation
with photons, ions and electrons, are widely used in the
field of polymers properties modifications for a number
of practical applications [5 – 7].
Three fundamental responses of polymers to electron
beam exist: crosslinking, i.e. formation of an insoluble
material, scissioning, thus the lowering of the molecular
weight of a material and neutral, hence there are a very
minimum or no effects on properties of the material.
Modification of the following properties are possible
with electron beam irradiation: mechanical strength,
hardness and strain, Young’s modulus, impact
toughness and resistance to bending, melting index,
swelling as well as dissolution properties like surface
topography, wetting properties, surface reactivity,
coatings adhesion by co-crosslinking organic layer and
substrate, et cetera.
Following the irradiation of polymer materials, reactive
products like excited atoms and molecules, ions as well
as radicals are formed. Accordingly, the process of the
irradiation induces secondary chemical reactions, like
cross-linking, decomposition and modifications, which
result in the structure and properties changing of
polymers. Generally, these changes depend on the type
and energy of incident particles, radiation doses, as well
as internal structures of polymers. At the present time,
the high energy electron beams are frequently used in
this field of polymers research because electron
irradiation is a very variable, fast and relatively
inexpensive method of polymers modifications.
The objective of presented work is to investigate
influence of electron beam irradiation on the dynamic
mechanical properties of non-vulcanized styrenebutadiene rubber blend, namely the effect of a high
energy electron beam irradiation on storage modulus,
loss modulus and loss factor values.
25
Materiálové inženýrství
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ISSN 0018-8069
time. Results are typically provided as a graphical plot
of E', E'' and tan δ versus temperature or time. In this
work, the dynamic mechanical analysis of the test
specimens was performed using Perkin Elmer PYRIS
Diamond Dynamic Mechanical Analyzer in the tension
clamp mode with temperature time scan. Measurements
were carried out at a frequency of 0.5 Hz, at a heating
rate of 3°C per minute and amplitude of 10 μm, in the
temperature range from 40 °C to 120 °C. Film strips for
DMA analysis were 50 mm long, 10 mm wide and
1 mm thick, approximately. The measurements were
done with non-irradiated as well as with irradiated
specimens at doses 100 kGy, 200 kGy, 250 kGy and
300 kGy. The storage modulus, loss modulus and the
damping factor were determined as the function of
temperature for all specimens under identical
experimental conditions. The used Perkin Elmer PYRIS
DMA analyzer can be seen in fig. 2.
Experimental
Materials
The composition of the blend was 23.5 % styrene and
76.5 % butadiene with additives such as ZnO, sulphur,
vulcanization acceleration and deceleration compounds.
Melt blending of the mixture in a Haake Rheomix was
performed at 110 °C and the rotary speed of 50 rpm for
10 minutes. Then the blend was compressed into 1mm
thick sheets under a pressure of 150 kg/cm2 in an
electrically heated hydraulic press at 110 °C. After three
minutes, the sheets were immediately cooled down to
25 °C between two plates.
Irradiation
A linear electron accelerator UELR-5-1S was used for
the irradiation of specimens. Electrons energy was
5 MeV, maximal output current on beam windows was
200 μA. Electron gun was equipped with BaNi indirect
heated cathode. Electrons were accelerated by a high
frequency electromagnetic field produced by magnetron
working in a pulse regime at frequency of 2998 МHz.
The vacuum system provided the high vacuum of 10-6 –
10-7 Torr inside the magnetron and resonator. Duration
of pulse was 3.5 μs, with frequency of pulses 240 Hz.
Irradiation was carried out under air cooling at room
temperature at a conveyor speed of 1 mm/s. The detail
of electron beam accelerator used in presented work can
be seen in fig. 1.
Fig. 2 Perkin Elmer PYRIS Diamond DMA apparatus
Obr. 2 Analyzátor Perkin Elmer PYRIS Diamond DMA
Results and discussion
Dependence of the storage modulus E', loss modulus E''
and damping factor tan δ on temperature in the range
from 40 °C to 120 °C at frequency 0.5 Hz for radiation
doses 0, 100, 200, 250 and 300 kGy can be seen in
fig. 3 to fig. 5. From these figures, it is clear that the
increase in a radiation dose leads to increase in storage
modulus with corresponding decrease in damping factor
in the whole temperature interval from 40 °C to 120 °C,
and it is the result of crosslinking degree rise of the
irradiated rubber blend with the radiation dose rise.
However, the significant increase in the storage
modulus in the whole monitored temperature interval
can be observed only at radiation dose of 300 kGy in
the comparison to the other doses differences between
values of storage modulus which declines with the
temperature rise. The significant differences between
values of damping factor at various temperatures from
monitored interval can be seen at radiation doses of 100
kGy, 200 kGy, 300 kGy. The increase in the radiation
dose leads to the increase in loss modulus. However,
from a certain temperature, which depends on radiation
dose, values of loss modulus are less in comparison to
a non-irradiated rubber blend. This temperature
increases with the increase in the radiation dose.
Fig. 1 The detail of an electron beam accelerator UELR 5-1C
Obr. 1 Detail elektrónového urýchľovača UELR 5-1C
Radiation doses of 50 kGy were applied in phases in
order to avoid the temperature rise at higher radiation
doses. The time elapsed between 2 phases of exposure
was about 20 min. Only one side of each test specimen
was exposed to irradiation as the thickness of specimen,
equal approximately 1 mm, is enough for penetration of
the electron beam. Applied radiation doses were 0 kGy,
100 kGy, 200 kGy, 250 kGy and 300 kGy.
Dynamic mechanical analysis
The Dynamic Mechanical Analysis (DMA) determines
storage modulus E', loss modulus E'' and the damping
factor tan δ, as a function of temperature, frequency or
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Materiálové inženýrství
Material Engineering
Fig. 3
Storage modulus E' as a function of temperature for various
electron beam radiation doses
Obr. 3 Elastický modul E' ako funkcia teploty pre rôzne
dávky žiarenia
Fig. 6
Temperature dependence of complex modulus E* for various
electron beam radiation doses
Obr. 6 Teplotná závislosť komplexného modulu E* pre rôzne
dávky žiarenia
Conclusions
Influence of high energy electron beam irradiation on
the dynamic mechanical properties of non-vulcanized
styrene-butadiene rubber blend in the temperature range
of its rubbery state has been carried out. The dynamic
mechanical analysis of examined rubber blend showed
that the storage and loss moduli as well as the damping
factor strongly depend on the radiation dose. The
increase in the radiation dose leads to the increase in the
temperature at which the vulcanization process of
rubber blend begins.
Fig. 4
Loss modulus E'' as a function of temperature for various
electron radiation doses
Obr. 4 Stratový modul E'' ako funkcia teploty pre rôzne
dávky žiarenia
Literature
[1] GODDARD, J.M., HOTCHKISS, J.H. Polymer surface
modification for the attachment of bioactive compounds. In
Progress in Polymer Science. ISSN 0079-6700, 2007, vol. 32, no.
7, p. 698-725
[2] YONG, Z. et al. Efficient Polymer Solar Cells Based on the
Copolymers of Benzodithiophene and Thienopyrroledione. In
Chemistry of Materials. ISSN 0897-4756, 2010, vol. 22, no. 9, p.
2696-2698
Temperature dependence of damping factor tan δ for various
electron beam radiation doses
Obr. 5 Teplotná závislosť stratového činiteľa tan δ pre rôzne
dávky žiarenia
Fig. 5
[3] ISACSSON, U. Laboratory investigations of polymer modified
bitumens. In Journal of the Asociation of Asphalt Paving
Technologists. ISSN 0270-2932, 2001, vol. 68, p. 35-63
[4] BELOSHENKO, V.A. et al. New methods of solid-phase
modification of polymers by simple-shear deformation. In Physical
Chemistry. ISNN 0012-5016, 2009, vol. 426, no. 1, p. 81-83
The storage modulus for all radiation doses as well as
loss modulus and damping factor started to be measured
in the rubbery state of specimen from temperature of
40 °C. Both, E' and E'' decrease with the increase of
temperature when tan δ increases. It means the decrease
of the stiffness of sample with the increase of
temperature. Subsequently, E' and E'' go through
a minimum value at temperature which depends on the
radiation dose – the higher dose leads to the increase of
the temperature and reaching the minimum value of
both dynamic moduli. On the contrary, tan δ goes
through its maximum. The increase in the radiation
dose leads to a shift of the tan δ maximum to lower
temperatures. Next, the increase in E' and E'' as well as
the decrease in tan δ are observed. This is caused by
crosslinking in a process of beginning of rubber blend
vulcanization. A complex modulus E* for various
electron beam doses as a function of temperature can be
seen in fig. 6.
[5] BURKERT, S. et al. Tuning of surface properties of thin polymer
films by electron beam treatment. In: Applied Surface Science.
ISSN-0169-4332, 2009, no. 255, p. 6256–6261
[6] KULSHRESTHA, V. et al. Microstructure change in
poly(ethersulfone) films by swift heavy ions. In Micron. ISSN:
0968-4328, 2010, no 41, p. 390–394
[7] DIPAK, S. Structural Modifications of Gamma Irradiated
Polymers: An FT-IR Study. In Advances in Applied Science
Research. ISSN: 2252-8814, 2012, vol. 3, no. 3, p. 1365-1371
[8] WON, Y.S. Electron beam treatment of chloroethylenes/air
mixture in a flow reactor. Radiation Physics and Chemistry.
ISSN: 0020-70552002, vol. 63, no. 2, p. 165–175
Review: prof. Ing. Darina Ondrušová, PhD.
prof. Ing. Tatiana Liptáková, PhD.
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Material Engineering
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ISSN 0018-8069
Relationship between the Geometrical Properties of the Fibers and Yarns
Závislosť medzi geometrickými vlastnosťami vlákien a priadzí
doc. Ing. Pavol Lizák, PhD., Ing. Jaroslav Ligas, PhD., Ing. Jela Legerská, PhD., Faculty of Industrial
Technologies, University of Alexander Dubček in Trenčín, I. Krasku 1809/34, 020 01 Púchov, Slovakia
Improving the quality of human way of life is a prerequisite for further development of the knowledge in society,
because economic growth results from human interaction skills and new technologies. Transferred to the fabric
understanding, improving quality in the textile industry is an increase in clothing comfort. The improvement of the
quality depends on necessary findings that should be based on deep knowledge. Therefore, it is important to know
the properties and geometrical arrangement of fibers and yarns. Main aim of this study was to examine the
relationship between the yarn fineness, hairiness of yarn and unevenness in increasing the number of twist.
Furthermore, the subject of this work was to design further analysis of wool yarns in relation to the assessment of
strength and also in relation to inequalities.
K zvyšovaniu kvality sú potrebné poznatky, ktoré by mali ísť do hĺbky. Preto je dôležité poznať štruktúru
a usporiadanie priadzí. Veľa informácií je možné získať z mikroskopických obrazov povrchu štruktúry, ktoré súvisia
s jemnosťou, priemerom, nerovnomernosťou a chlpatosťou. Zákrut vyjadruje zakrútenie vlákien v smere skrutkovice
okolo osy priadze, vyjadrené počtom otáčok na jednotku dĺžky. Je možné ho vypočítať z podielu počtu otáčok n
a odťahovej rýchlosti v alebo iným spôsobom pomocou zákrutových koeficientov. Zaplnenie je podiel vlákien vo
vláknovom útvare. Keďže vlákna sú základné stavebné jednotky všetkých textílií, sú podstatou vzniku priadze, ktorá
je často pojatá ako jednoduchý textilný útvar, ktorý je východiskom pre zložený útvar, konkrétne pre tkaninu. Preto
bolo potrebné analyzovať jednotlivé vlákna zmesi. Vhodným zmesovaním textilných vlákien sa dosiahnu ešte lepšie
vlastnosti textilných výrobkoch Polyamidove vlákna sú vhodne na zmesovanie vlny napr. majú väčšiu pevnosť a tým
zlepšujú pevnostné charakteristiky. K tomuto zisteniu sú potrebné aj poznatky o geometrických vlastnostiach
skúmaných vzoriek. Cieľom tejto práce bolo skúmať závislosť medzi jemnosťou priadze, chlpatosťou priadze a jej
nerovnomernosťou pri zvyšujúcej hodnote počtu zákrutov. Ďalej predmetom tejto práce bolo prevedenie ďalšej
analýzy vlnárskych priadzí vo vzťahu k pevnosti a posúdenie tiež vo vzťahu k hmotnej nerovnomernosti.
Geometric properties by Militký [1] characterize the
shape and dimensions of the fibers. Textile fibers are
generally regarded as very fine cylindrical bodies. On
closer inspection, however, their shape, we find that
only a small part of the fibers corresponds to this
concept. For accurate characterization of fiber geometry
it is therefore necessary to know not only the length and
thickness of the fibers, but also cross-sectional shape,
surface structure of the fibers and elongated shape.
of fiber. The yarns were taken for analysis of individual
fibers. Using a measuring instrument that contains NIS
element their diameter was measured. The fibers were
classified according to the individual composition of
a mixture, where the mean of individual fibers as well
as fiber mixture is detected.
The table 1 and 2 contains a mixture of fiber diameter
and fineness of fibers but also the fiber fineness. These
values from tab. 3 were calculated according to the
equation [7].
Measurement of the geometric and structural
properties
From the aspect of particle and fiber diameter, the image
analysis is used for the measurement of diameters
Tab. 1 The diameter of each fiber and total fiber diameter
Tab. 1 Priemer jednotlivých vlákien a celkový priemer zmesi
Sample No.
1
2
3
4
5
dfibres total [tex]
19.734
20.84
23.17
18.02
21.41
composition
wool
PAD
wool
PAD
wool
wool
PAD
wool
PAD
dfibres total [tex]
20.98
14.75
20.76
21.16
23.17
19.07
13.83
22.07
18.79
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Materiálové inženýrství
Material Engineering
Tab. 2 The fineness of the fiber and the overall fineness of fibers
Tab. 2 Jemnosť jednotlivých vlákien a zmesi
Sample No.
1
2
3
4
5
Tfibres total [tex]
0.404
0.4376
0.556
0.3352
0.467
composition
wool
PAD
wool
PAD
wool
wool
PAD
wool
PAD
Tfibres total [tex]
0.456
0.196
0.446
0.404
0.556
0.376
0.172
0.504
0.319
Tab. 3 Selected geometric characteristics of the fibers
Tab. 3 Vybrané geometrické charakteristiky vlákien
Sample
No.
1
S
[µm2]
314.1
de
[µm]
20
qt
[0..1]
0.0135
Av
[m2.kg-1]
158
2
340.2
20.82
0.042
156
3
421.2
23.16
0.1585
151
4
260.6
18.22
0.099
188
5
362.1
21.48
0.0705
155
Result of measurement
The highest overall average fiber mixture should have
sample No.3, the sample composition is 100% of wool.
The lowest average was observed for mixed sample
No. 4. The analysis of the composition of the wool
fibers and PAD led to interesting information. Fiber
fineness PAD for sample No. 1 and 4 were lower than
the fineness of fibers waves. On the other hand, fiber
fineness PAD for sample No. 1 and 5 have similar
values as the fineness of wool fibers.
The highest total finesse of fiber mixture was observed
for sample No. 3, the sample composition with 100% of
wool. The lowest total fineness of mixed sample was for
No. 4. The sample No. 2 d exhibited the highest fiber
fineness. The lowest fiber fineness PAD was observed
in the case of sample No. 4. According to the analysis of
fineness of fibers of the mixture, the highest grade was
highest grade shown in the case of fiber sample No. 5
and the lowest grade of fineness was found out for
sample No. 4
Fig 1 Correlation between fineness T [tex] and coefficient of yarn
variation CV [%]
Obr. 1 Korelačná závislosť medzi jemnosťou priadze
a nerovnomernosťou priadze CV [%]
Mean of twist yarns varies with different yarns in the
range 454.67 zm-zm 1-826-1. The highest value of the
twist was typical for sample No. 5 while the twist yarn
No. 3 (yarn with 10 0% of wool composition) showed
the lowest value of the twist.
Fig. 2 Correlation between dependency of fineness T [tex]
and hairiness H [-]
Obr. 2 Korelačná závislosť medzi jemnosťou priadze T [tex]
a chlpatosťou [-]
Mean yarn fineness varies with experimental yarns
between 95.15 tex. tex to 124.65. The greatest value of
fineness was observed for sample No.3, and the lowest
value was recognized for yarn No. 4. Longitudinal
views were made for fibers and filaments at PAD
waves. We can see wave characteristic scales on the
surface of the fibers.
Conclusions
Fig. 1 and fig. 2 shows the information on correlation
between fineness and the following characteristics: CV,
hairiness, relative strength and elongation.
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The fineness and CV pulls is valid, according to this
relationship as a general rule, with an increasing number
of fibers, CV decreases. Trend has a similar tendency.
Acknowledgement
We wish to thank the Slovak Grant Agency (KEGA: 002
TnUAD 4/2011) for the financial support.
The plot of correlation between fineness and hairiness
increases with the increase of fineness and roughness.
Generally, the thicker yarn means larger number of
fibers and thus higher hairiness.
Literature
[1] LIZÁK, P., MILITKÝ, J. Technické textilie. Ružomberok, 2002
[2] LIZÁK, P., LIGAS, J. China, s export expansion in the textile
industry. seminár TEXCO´2010. s. 20-21
The expression of level of tightness between the
descriptive characteristics was characterized on the
basis of the correlation coefficients:
[3] LIZÁK, P., LIGAS, J. Základy textilnej a odevnej výroby. 2010
Wlok, 1979. 29 s. ISBN 978-80-969610-8-5
If R = 0.9364 shows that the degree of fineness and
tightness to hairiness is very high. If R = 0.4430 shows
that the rate of leakage to fineness and CV shows
mildness.
[6] MILITKÝ, J. Technické textílie vybrané kapitoly. Liberec: TU,
2002
[5] KOLEKTÍV AUTOROV, ED. KŘEMENÁKOVÁ, D. Seminár
textílie v novom tisícročí II. TU Liberec, 2004
[7] LIGAS, J. Komplexné hodnotenie povrchových, štruktúrnych
a mechanických vlastností vlnených a zmesových priadzí –
dizertačná práca, Púchov 2012
Review: prof. Ing. Tatiana Liptáková, PhD.
doc. Ing. Iva Sroková, CSc.
_____________________________________________________________________________________________
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Materiálové inženýrství
Material Engineering
Comparison of Influence of Silica Fillers on the Rubber Compounds
Processing
Porovnanie vplyvu plnív na báze siliky na spracovateľnosť gumárenských
zmesí
prof. Ing. Darina Ondrušová, PhD., Ing. Slavomíra Domčeková, Ing. Lenka Špániková, Ing. Mária Kopcová,
Ing. Ivan Cehlárik, Ing. Janka Jurčiová, PhD., Faculty of Industrial Technologies in Púchov, University of
Alexander Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia
The presented work deals with the study of influence of prepared monodispersive silica on the elastomer compounds
processing. The compounds were filled with various types of precipitated silica and colloidal silica and they were
combined with carbon black. Used silica filler was Ultrasil VN3 which is one of the most used precipitated silica in
the industry. Besides Ultrasil VN3, colloidal silica was also used and it was stabilized by boiling in conditions of
0 hours, 3 hours and 5 hours. Rheological properties of materials and their deflection in comparison to Newtonian
liquids are used to determine the contribution of colloidal silica in comparison to precipitated silica. From the
obtained results, we can conclude that the rubber compounds which were filled with colloidal silica shows lower
deflection from the Newtonian behaviour than it is in the case of industrially used precipitated silica Ultrasil VN3
and it means that the sample shows better rheological properties. Based on these findings, it is possible to suppose
better processing properties in the case of the colloidal silica in comparison to industrially used precipitated silica.
Práca sa zaoberá skúmaním vplyvu laboratórne pripravenej monodisperznej koloidnej siliky na spracovateľnosť
elastomérnych zmesí v porovnaní s účinkom komerčnej zrážanej siliky a sadzí. Vo funkcii plniva do prírodného
kaučuku sa použili dva druhy siliky (Ultrasil VN3 a monodisperzná koloidná silika) a sadze typu N339.
Monodisperzná koloidná silika bola stabilizovaná pri podmienkach 0, 3 a 5 hodín varu. Porovnávali sa zmesi, ktoré
boli plnené iba samotnou silikou pri dávkovaní 40 dsk a zmesi, do ktorých bola použitá kombinácia sadzí a siliky,
pri dávkovaní 20:20 dsk. Meranie odklonu od newtonovského toku na prístroji RPA 2000 viedlo k určeniu
komplexnej viskozity a šmykovej rýchlosti. Zo závislosti týchto dvoch veličín boli vypracované tokové krivky. Z nich
sa stanovil odklon od ideálneho newtonovského toku „n“. Čím vyžšie hodnoty „n“ skúmaná vzorka dosahovala, tým
bol odklon od newtonovského správania menší, čo znamená, že vzorka dosahuje lepšie tokové vlastnosti a možno
predpokladať jej lepšiu spracovateľnosť. Maximálnu viskozitu, teda najväčší odklon od newtonovského správania
vykazuje zmes plnená Ultrasilom a zmes plnená kombináciou Ultrasilu a sadzí. Zmesi plnené koloidnou silikou
vykazujú odklon od newtonovského správania menší než priemyselne používaná zrážaná silika Ultrasil VN3. Z tohto
dôvodu je možné predpokladať lepšiu spracovateľnosť zmesí plnených monodisperznou koloidnou silikou v prípade
extrúzie alebo vstrekovania.
Utilisation of the rubber products is connected with
increasing application in many branches of industry
including the production of the tires, seals and many
other rubber products. Due to continual increasing
requirements for the products and their performance
under the hard environment conditions lead to the
higher requirements for the construction materials.
precipitated silica because the precipitated silica is the
most used material in the industry and this material
could be substituted by colloidal silica because of its
lower cost.
Compounds which were filled by colloid silica show the
deflection from the Newtonian behaviour and this
deflection is lower than the industrially used
precipitated silica Ultrasil VN3 and it is closely
connected with the fact that the sample shows the better
properties from the aspect of rheological properties and
therefore it is much more suitable in relation to better
processing during extrusion and injection.
Another aspect which must be considered is the cost of
given rubber products because increasing quality has to
be effective from the economical point of view. One of
the most important raw materials used in the rubber
compounds are fillers. These are added to the rubber
compounds because of the improving the properties
while the cost of the final product must be preserved.
This mentioned facts are the reason for investigation of
the influence of the colloidal silica in comparison to
industrially used precipitated silica. Rheological
properties of materials and their deflection in
comparison to Newtonian liquids are used to determine
the contribution of colloidal silica in comparison to
Rheological properties of polymer materials
Rheology is the science which studies changes of the
shape dimensions substances during the action of the
outside forces. In the strict sense of words, it means the
study of liquids flow [1]. The flow is the deformation
which is the function of the time. Ideal liquid is the
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ISSN 0018-8069
and 2 and in figs. 1 and 2. The higher values of „n“ for
investigated sample represented the lower deflection
from Newton’s liquid behaviour and it means that the
sample shows the better properties from the aspect of
rheological properties and therefore it is much more
suitable in relation to better processing during extrusion
and injection. There is the expectation that compounds
with the lower value of „n“ will not be processed easily
due to their higher stiffness as well as higher reinforcing
effect of used fillers.
substance which is the deformed because of the outside
forces action due to the time and it means that the liquid
is being under flowing [2]. In generally, the dependence
of shear stress from the shear rate is called flow curve.
Flow curve in the shape of the straight line is used only
for the materials with ideal viscosity and their viscosity
is not changed in dependence on shear rate. From the
aspect of rheological science, these types of materials
are called Newtonian liquids [3].
Determination of flow curves on RPA 2000
Tab. 1 The values of deflections from the Newton’s liquid behaviour
and the complex viscosity * for compounds with 40 phr of
silica
Tab. 1 Hodnoty odklonu od newtonovského správania a komplexnej
viskozity * pre zmesi s 40 dsk siliky
Flow curves express the functional dependence between
shear stress δ and shear rate γ. Basic rheological
parameters, such as shear stress and shear rate can not
be measured directly but they are proportional to
different variables but it depends on the type of utilized
measuring device. Index „n“ is commonly calculated by
help of the flow curves which were gained by
measuring device RPA. Then, it is necessary to subtract
the value of the complex viscosity η* while the
temperature is constant and the shear rate is different.
After that, the method of the least squares of slope of
the line is used for determination of coefficient „n“ and
the calculation is done by help of following equation:
Compounds
Deformation
(%)
x log  and y log*
then n = the slope of line +1.
Measurements and results of flow properties
The compounds were prepared by two-step of mixing in
laboratory mixer called PLASTOGRAPH-BRABENDER
in the standard way [4].
NRU

NRS0h
NRS3h
NRS5h
η* (Pa.s)
(s-1)
0.111
0.08
106595
37553
34777
38583
0.333
0.24
96656
35970
33667
36794
0.667
0.48
83035
34187
32045
35051
1.000
0.73
72654
32737
30802
33308
3.897
2.29
38920
23098
22152
23228
6.228
4.02
29469
18737
17993
18769
11.456
8.98
19020
13016
12601
12997
29.380
21.46
9831
6799
7153
7137
39.089
28.90
7879
5522
5670
5821
45.063
32.92
6985
4982
5070
5264
0.529
0.664
0.683
0.666
Coefficient "n"
The effect of the addition of the silica in compound was
being watched at dose 40 phr as well as there was the
observation of the influence of silica with carbon black
at dose 20:20 phr.
The compound filled only with Ultrasil and Ultrasil with
carbon black was labelled as NRU and NRSU. NRS0h,
NRS3h and NRS5h for colloidal silica were also
labelled while the given silica was stabilized by boiling
for 0 hours, 3 hours and 5 hours. Compounds in
combination with colloidal silica prepared by boiling for
0 hours, 3 hours and 5 hours and combined with carbon
black were labeled NRSS0h, NRSS3h, NRSS5h.
Fig. 1 Assesment of flow indexes for compounds with 40 phr silica
Obr. 1 Hodnotenie indexov toku pre zmesi s obsahom 40 dsk siliky
The measurement of deflection from o Newton’s flow
which was carried out on the measuring device RPA
2000 led to identification of complex viscosity and
shear rate. The flow curve was determined from
dependences of these two values and these values were
used for determination of ideal Newton’s flow „n“. The
tested samples were investigated at 100 °C and
frequency was 50 Hz as well as the deformation was
being changed in the range of (0.111 – 45.063) %. The
values of „n“ specified on the basis of the slope of the
flow curves. The results of measurements are in tabs. 1
The measurement of the deflection from Newton’s
liquid behaviour for compounds filled with dose of
40 phr of silica shows the highest values of „n“ and it
means that the lower deflection from Newton’s liquid
behaviour was gained in the case of the compounds
NRS0h, NRS3h and NRS5h which were filled with
laboratory prepared colloidal silica. The lowest value of
„n“ was observed in case of the compound NRU filled
with Ultrasil VN3.
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The values of deflections from the Newton’s liquid behaviour
and the complex viscosity * for compounds with 20 phr of
silica and 20 phr of carbon black
Tab. 2 Hodnoty odklonu od newtonovského správania a komplexnej
viskozity * pre zmesi s 20 dsk siliky a 20 dsk sadzí
values to coefficient „n“, only compounds with label
NRSS5h showed slightly worse flow properties. If we
compare the compounds which were filled with silica
with the compounds which were filled by silica
combined with carbon black, we can conclude, that
there was not any fundamental difference in their flow
properties.
Tab. 2
Compounds
Deformation
(%)
NRSU
NRSS0h

NRSS3h
NRSS5h
* (Pa.s)
(s-1)
0.111
0.08
46981
33500
33842
38091
0.333
0.24
44608
32368
32703
36538
0.667
0.48
40554
30627
30889
34121
1.000
0.73
37644
29271
29407
32222
3.897
2.29
24628
21035
21044
22215
6.228
4.02
19374
17068
17079
17825
11.456
8.98
12863
11778
11649
12352
29.380
21.46
7115
6172
6230
6498
39.089
28.90
5723
4925
4957
5186
45.063
32.92
5061
4393
4408
6435
0.599
0.640
0.638
0.625
Coefficient "n"
Conclusions
The maximum viscosity and thus the largest deflection
from Newton’s liquid behaviour was observed for
compound filled with Ultrasil as well as for the
compound which was filled with combination of
Ultrasil and carbon black. Compounds filled only with
silica or with the combination of the silica and carbon
blacks show mutually comparable values of „n”. There
were not any significant differences. It means that in the
case of the measurements of viscosity as a property of
the material flow, the behaviour of these compounds
would be similar. The comparison of the results for
deflection from Newton’s liquid behaviour is closely
connected with the determination of the index of the
flow „n”. Obtained value of index of flow „n”
confirmed that the compounds which were filled with
monodispersive colloidal silica shows better results of
rheological properties than the compounds filled with
commertial precipitated silica. It can be assumed, that
the compounds filled with monodispersive colloidal
silica are much more suitable in relation to better
processing during extrusion and injection.
Acknowledgement
The authors are grateful to the Slovak Grant Agency
VEGA 1/0530/11 for financial support.
Literature
[1] ŠIMEK, I. Fyzika polymérov. Bratislava: SVŠT, 1987. 275 s.
Fig. 2
Assesment of flow index for compounds with 20 dsk of silica
and 20 dsk of carbon black
Obr. 2 Hodnotenie indexov toku pre zmesi s obsahom 20 dsk siliky
a 20 dsk sadzí
[2] ŠPIRK, E.: Reológia polymérnych systémov. FPT Púchov, 2004
[3] LIPTÁKOVÁ, T. a kol. Polymérne technické materiály:
Vysokoškolská učebnica pre technické smery, 2009. 184 s.
[4] Príprava gumárenských zmesí STN 62 1425
The measurement of the deflection from Newton’s
liquid behaviour for compounds filled with 20 phr of
silica and 20 phr of carbon black showed that the lowest
value of „n“ was measured for the sample NRSU which
was filled with Ultrasil VN3. According to the given
mentioned facts, it could be concluded that this
compound has the worst flow properties and it means
the worst processing. Compounds which was filled with
laboratory prepared colloidal silica showed comparable
Review: prof. Ing. Tatiana Liptáková, PhD.
doc. Ing. Iva Sroková, CSc.
33
Materiálové inženýrství
Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Study of the Impact of New Nanofillers Based on Clinoptilolite on the
Properties of Rubber Compounds
Skúmanie vplyvu nových nanoplnív na báze klinoptilolitu na vlastnosti
gumárenských zmesí
prof. Ing. Darina Ondrušová, PhD., Ing. Lenka Špániková, Ing. Mária Kopcová, Ing. Slavomíra Domčeková,
Ing. Michaela Ďurčeková, prof. Ing. Eugen Jóna, Dr.Sc., Faculty of Industrial Technologies in Púchov,
University of Alexander Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia
The presented work deals with the preparation and utilization of modified forms of zeolite - clinoptilolite in function
of alternative nanofillers in the rubber compounds. The zeolites can be considered as environmentally friendly
natural materials applicable in various fields of life. The zeolites are added into rubber compound as replacing
agent of standard filler – carbon black. Two groups of nanofillers were prepared: monoionic form Ni(II) and
organic form – organozeolite (containing organic dithiophosphate accelerator). All prepared nanofillers were
applied into rubber compounds. According to the measured values of vulcanization behaviour of rubber compounds
and physical and mechanical properties of vulcanizates the impact of prepared nanofillers on quality of modified
rubber compounds was evaluated. The found values were compared to the values of standard rubber compounds
containing the commercial filler - carbon black.
Prezentovaná práca je zameraná na využitie pripravených modifikovaných foriem prírodného zeolitu - klinoptilolitu
vo funkcii nanoplnív do gumárenských zmesí. Zeolity predstavujú rozsiahlu skupinu kryštalických
hlinitokremičitanov využiteľných vo funkcii ekologických nanoplnív, pričom požadované vlastnosti gumárenských
zmesí zostávajú zachované. Pripravené modifikované formy možno rozdeliť do dvoch základných skupín:
monoiónová forma Ni(II) a organická forma (s obsahom organického urýchľovača vulkanizácie). Monoiónová
forma zeolitu bola pripravená výmennou reakciou medzi prírodným zeolitom a roztokom s obsahom katiónu Ni(II).
Organická forma zeolitu (organozeolit) sa získal sýtením prírodného zeolitu výparmi organického urýchľovača na
báze ditiofosfátu. Ni(II) zeolit a organozeolit boli do gumárenskej zmesi pridané s cieľom nahradiť štandardné
plnivo - sadze. Modifikované gumárenské zmesi s obsahom modifikovaných foriem zeolitu boli porovnávané so
štandardnou gumárenskou zmesou. Hodnotené boli vulkanizačné charakteristiky gumárenských zmesí a fyzikálnomechanické vlastnosti vulkanizátov. Na základe získaných výsledkov možno odporučiť plnivá na báze prírodného
zeolitu ako ekologickú náhradu štandardne využívaného plniva gumárenských zmesí – sadzí. Využitie týchto nových
nanoplnív môže prispieť k znižovaniu negatívnych vplyvov gumárenskej výroby na okolité prostredie a ľudí
v ňom žijúcich.
Last decades have been characterized by very strict
criteria and requirements for the manufacture of
products. The most highly rated aspects especially
include: improving the quality of manufactured
products, reducing the negative impacts of production
and reducing the negative impacts of the use of products
on the environment and human health. In the rubber
industry, there is also an effort to produce high-class
and environmentally friendly products. On the basis of
the mentioned facts, the replacement of hazardous
substances (carbon black) by more acceptable agents is
needed but it is necessary to respect economy, ecology
and production safety. Carbon black is a hazardous
substance because of its negative impact on
environment and on health of human being.
Replacement of carbon black by some ecological fillers
(e.g. zeolite) is one of the ways to solve this problem.
which intersect at cavities (cages). These cavities
contain exchangeable metal cations (Na+, K+, etc.) and
can hold removable and replaceable guest molecules.
According to their properties they are used as cation
exchangers for water softening, as molecular sieves for
separating molecules of different sizes and shapes (e.g.
as drying agents), and as catalysts in wide variety of
reactions [1].
Organozeolites are crystalline materials that possess
both a zeolite-like inorganic skeleton and organic
moieties covalently bound to the skeleton. We can also
say that organozeolites are zeolites, the surface which
was modified by organic surfactants [2].
Experiment
Natural zeolite was processed by crushing and sieving
to a particle size less than 0.063 mm. Monoionic form
Natural zeolites are a class of crystalline
aluminosilicates based on rigid anionic frameworks with
well-defined pores (channels) running through them,
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ISSN 0018-8069
Materiálové inženýrství
Material Engineering
Ni(II) of zeolite was prepared by the exchange reaction
between natural zeolite - clinoptilolite and the Ni(II)
ionic solution. During the preparation of organo-zeolite,
the powdered natural clinoptilolite was saturated by the
vapors of organic dithiophosphate accelerator. Both this
experiments were made at laboratory temperature.
These prepared forms of zeolite were used in function
of mineral nanofillers of rubber compound as
replacement of standard filler – carbon black. One
reference rubber compound with filler of carbon black
was prepared as a comparative compound. The model
rubber compounds were prepared by two-step mixing in
laboratory
blender
called
PLASTOGRAPHBRABENDER in a standard way [3]. Both steps of
mixing were carried out at the temperature 90 °C and a
rate of rotation blades was 50 rpm/min. In the first step,
activator of vulcanization (ZnO) together with the
mentioned fillers and the natural rubber were mixing for
preparation of rubber compounds. In the second step,
accelerator of vulcanization as well as polymer sulphur
as a vulcanization agent were added and then the
compounds were again mixing. Composition of
modified rubber compounds with standard filler and
with prepared nanofillers is shown in tab. 1.
Results and discussion
Measured and calculated results from determination of
rheology and vulcanization behaviour of prepared
rubber compounds are shown in tab. 2 and in figs. 1 - 3.
Tab. 2 Vulcanization and processing characteristics of the rubber
compounds
Tab. 2 Vulkanizačné a spracovateľské vlastnosti gumárenských
zmesí
R
1
2
3
4
5
6
5
Mmax
t90
t02
[Nm] [min] [min]
94.3
15
1.8
79.8 18.3
1.5
74.9 19.5
1.8
77.5 21.7
2
73.9 16.6
2
69
16
3.2
66.9 13.5
2.1
Rv
[min-1]
7.576
7.042
5.65
5.076
7.353
7.813
8.772
If the maximum torque moment MH (fig. 1) for all
compounds compared with the standard compound have
lower values, so it could be said that all compounds
have lower values of viscosity compared with R at the
end of the measurement.
Tab. 1 Composition of modified rubber compounds (samples 1 - 6)
and standard rubber compound (R)
Tab. 1 Zloženie modifikovaných gumárenských zmesí (1 – 6)
a štandardnej gumárenskej zmesi (R)
R
1
2
3
4
Ingredient
[phr]
I. step
SMR
100 100 100 100 100
ZnO
8
8
8
8
8
Stearic Acid
2
2
2
2
2
Carbon Black 55 50 45 35 50
Ni(II) zeolite
5 10 20 Organozeolite 5
II. step
Sulphur
6
6
6
6
6
Accelerator
1.3 1.3 1.3 1.3 1.3
Mmin
[Nm]
12.8
10.7
10.2
15.9
11.2
16.3
18
6
100 100
8
8
2
2
45 35
10 20
Fig. 1 Maximal torgue moment MH of model rubber compounds
Obr. 1 Maximálny krútiaci moment MH gumárenských zmesí
6
6
1.3 1.3
*phr = parts per hundred rubber
After mixing, rubber compounds were left for 24 hours
at laboratory temperature and then vulcanization curves
were done by vulcameter MONSANTO 100 at the
temperature 150 °C during 60 min. Rheological and
vulcanization properties (ML, MH, tS, t90, RV) of
prepared rubber compounds were investigated [4].
Vulcanization of rubber compound was done in
laboratory vulcanization press called BUZULUK 400 x
400 at a pressure of 20 MPa and at temperature 150 °C
[5]. Values of hardness were founded out by hardness
tester IRHD [6]. Determination of physical and
mechanical properties of vulcanized rubber - tensile
properties (tensile strength, tensibility) was done by
instrument INSTRON [7]. The founded values of
prepared modified rubber compounds were compared
with the values of reference rubber compound with
standard filler.
Fig. 2 Scorch of time t02 of rubber compounds
Obr. 2 Počiatočný čas vulkanizácie t02 gumárenských zmesí
Increasing the scorch of time t02 (fig. 2) represents
a positive aspect of technological process because
represents an increase of the processing safety of rubber
compounds.
35
Materiálové inženýrství
Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Fig. 3 Rate coefficient of vulcanization RV of rubber compounds
Obr. 3 Rýchlostný koeficient vulkanizácie RV gumárenských zmesí
Fig. 6 Hardness of vulcanizates
Obr. 6 Tvrdosť vulkanizátov
The values of the coefficient of vulcanization rate Rv
(fig. 3) confirm the effect of increasing the
vulcanization rate with increasing the addition of
organo-zeolite in contrast with addition of monoionic Ni
(II) form of zeolite. This effect is clear evidence of an
additional accelerating impact of organo-zeolite
containing accelerator in its structure.
Conclusions
The vulcanization characteristics and physical and
mechanical properties of the prepared rubber
compounds with modified composition were studied.
The obtained values of six model rubber compounds
with the addition of new mineral nanofillers based on
zeolite were compared with the characteristics of
standard rubber compound R which contained only
carbon black as an filler.
The results of physical and mechanical properties of
prepared vulcanizates are presented in tab. 3 and in
figs. 4 - 6.
The study of modified rubber compounds with the
addition of natural zeolite as nanofiller confirmed that
natural zeolite – clinoptilolite may be used as
environmentally friendly substituent of carbon black for
application in rubber compounds improving the physical
and mechanical properties.
Tab. 3 Physical and mechanical properties of prepared vulcanizates
Tab. 3 Fyzikálno-mechanické vlastnosti pripravených vulkanizátov
R
1
2
3
4
5
6
Tensile strength
[MPa]
21.33
19.24
16.06
14.74
17.94
16.09
17.85
Tensibility
[%]
355
275
288
299.8
330.2
364.8
457.2
Hardness
[IRHD]
64.6
68.38
67
66.38
65.13
65.13
57.5
Acknowledgement
The authors are grateful to the Slovak Grant Agency
VEGA 1/0530/11 for financial support.
Literature
[1] SMART, L., MOORE, E. Solid state chemistry: an introduction,
3rd edition, CRC Press, 2005. 407s. ISBN 0-7487-7516-1
[2] MAEDA, K., MIZUKAMI, F. Organozeolite materials and their
properties. In Catalysis Surveys from Japan, 1999, Vol. 3, no. 2,
p. 119-126
[3] STN 62 1425: Príprava gumárenských zmesí
[4] STN 62 1416: Gumárenské zmesi. Stanovenie vulkanizačných
charakteristík na vulkametri
Fig. 4 Tensibility of vulcanizates
Obr. 4 Ťažnosť vulkanizátov
[5] STN 62 1425: Kaučuky. Príprava a vulkanizácia kaučukových
zmesí. Zariadenia
A comparison of the measured values of tensile strength
shows lower values for rubber compound with prepared
zeolite nanofillers. Values of tensibility (fig. 4)
represent increasing values of tensibility with increasing
amount of modified zeolite addition. The sample 5
shows the highest value of tensibility.
[6] ISO48: Rubber, vulcanized or termoplastic. Determination of
hardness (hardness between 10 IRHD and 100 IRHD)
[7] STN ISO 37: Guma a termoplastové elastoméry. Určovanie
ťahových vlastností
Review: prof. Ing. Tatiana Liptáková, PhD.
doc. Ing. Iva Sroková, CSc.
The high values of hardness were reached at all samples
except for sample 6. Sample 4 and 5 show comparable
values of hardness to sample R.
36
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Materiálové inženýrství
Material Engineering
Preparation, Characterization and Thermal Properties of
Hydroxyethylcellulose Cinnamates
Príprava, charakterizácia a termické vlastnosti cinamátov HEC
Ing. Vladimíra Krmelová, PhD., Ing. Katarína Kostelanská, PhD., doc. Ing. Iva Sroková, PhD., doc. Ing.
Milan Olšovský, PhD., University of Alexander Dubček in Trenčín, Faculty of Industrial Technologies,
I. Krasku 491/30, 020 01 Púchov, Slovakia, RNDr. Vlasta Sasinková, Slovak Academy of Sciences, Institute of
Chemistry, 845 38 Bratislava, Slovakia
Hydroxyethylcellulose cinnamates (HEC-Cin) were prepared form hydroxyethylcellulose by esterification with
cinnamic acid (CA) and cinnamoyl chloride (ClCA). The chemical modification was performed in different reaction
media DMSO and DMF/pyridine with 4-DMAp as catalyst and dicyclohexylcarbodiimide (DCCI) as activator of
cinnamic acid, at various reaction conditions (mass ratio, time, temperature). The structural properties of the
prepared polysaccharides were characterized by Fourier-transform infrared (FT-IR) and UV spectroscopy, which
confirmed that HEC-Cin derivatives with low degree of substitutions were prepared. Their thermal stability was
evaluated by thermogravimetry (TGA) too.
Cinamáty hydroxyetylcelulózy (HEC-Cin) sa pripravili dvoma metodami esterifikácie. A to chemickou modifikáciou
HEC kyselinou škoricovou (CA)použitím aktivátora karboxylových kyselín dicyklohexylkarbodiimidu (DCCI) a za
katalýzy 4-DMAp v prostredí DMSO. Klasická esterifikácia s chloridom kyseliny škoricovej (ClCA) prebiehala
v reakčnom prostredí DMF/pyridín za katalýzy 4-DMAp. Varirovaním reakčných podmienok a to hmotnostných
pomerov východiskovej HEC:modifikator (CA, ClCA), čas a teplota sa pripravili vodorozpustné deriváty HEC.
Následne sa charakterizovali FT-IR a UV spektrami, ktoré potvrdili prítomnosť esterovej skupiny. V FT-IR
spektrách pripravených HEC-Cin sa sledoval najmä pás pri vlnočte ~ 1703 cm-1, prislúchajúci vibráciám esterových
skupín, ktorý bol nižší v porovnaní s esterovými skupinami (~1732 cm-1) čo súviselo s konjugáciou násobnej väzby
a aromatického jadra zvyšku CA. UV spektrá cinamátov HEC vykazovali absorpčný pás v oblasti vlnových dĺžok od
240-340 nm s absorbčným maximom pri vlnovej dĺžke 280 nm, ktorý zodpovedá π-π* konjugácii C=C väzby
s aromatickým jadrom cinamátovej skupiny. U vybraných derivátov sa študovali termické vlastnosti. Relatívne
najviac esterifikovany derivát HEC-Cin3 mal mierne zvýšenú termickú stabilitu v porovnaní s východiskovou HEC.
The increasing interest in biocompatible and
biodegradable materials makes polysaccharides
attractive as natural and sustainable polymeric resources
which can be modified for special performance in
various commercial applications. The covalent
anchoring of hydrophobic side-chains in water-soluble
polysaccharides affords water-soluble amphiphilic
derivatives which usually exhibit associative, surfaceactive or functional properties with possible application
as polymeric surfactants, surface-active agents and etc.
Non-toxic properties and biodegradability are the
advantages of these amphiphilic polysaccharides. Among
the commercial polysaccharides, the water-soluble,
nonionic cellulose ether hydroxyethylcellulose (HEC)
has been widely used as a source of biopolymers for
further chemical modification. HEC grafted by various
alkyl groups ranging from C12 to C24 was the first one
among amphiphilic polysaccharides characterized by
associative properties [1]. A large variety of HEC
derivatives were prepared by conventional and
microwave assisted modification of the hydroxyl groups
of HEC using acyl chlorides, mixed anhydrides, vinyl
laurate, methyl laurate as well as methyl ester of rape
seed oil [2, 3]. In our previous work, cinnamic acid
esters of various polysaccharides with antioxidative
properties useful as alternative of synthetic antioxidant
were prepared [4]. In this study the preparation of HEC
cinnamates by esterification with cinnamic acid as well
as with cinnamoyl chloride was investigated. Prepared
HEC-Cin derivatives were characterized by FT-IR and
UV spectroscopy and thermogravimetric analysis
(TGA) was used for evaluation of their thermal stability.
Experiment
Materials:
Hydroxyethylcelulose (HEC, MS =2.5; DS = 1.0) was
from HOECHST (Frankfurt, Germany). The cinnamic
acid
(CA),
cinnamoyl
chloride
(ClCA),
dicyclohexylcarbodiimid
(DCCI)
and
4dimethylaminopyridine (4-DMAp) were commercial
products from Sigma-Aldrich Chemie (Steinheim,
Germany). N,N – Dimethylformamide (DMF) and
acetone were from Lachema (Brno, Czech Republic).
Dimethylsulfoxide (DMSO) was from AFT, Ltd.
(Bratislava, Slovak Republic). The reactions were
carried out in the dark environment to avoid
photoreaction as described by Wondraczek [5].
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ISSN 0018-8069
Materiálové inženýrství
Material Engineering
Methods:
Fourier-transform infrared (FT-IR) spectra were
obtained on the Nicolet 6700 spectrometer with an ATR
extension piece (Smart orbit diamond) with using 128
scans at resolution of 4 cm-1 at the Institute of
Chemistry, SAS (Bratislava, Slovak Republic).
UV spectra of HEC-Cin derivatives dissolved in water
(4 mg/10 ml) were obtained on the SpectroFlex 6600
(WTW Weilheim, Germany).
TGA measurements were performed on a Thermobalance
Mettter Toledo TGA/SDTA 851e thermogravimetric
analyzer. Measurements were performed under nitrogen
atmosphere using a heating rate of 10 °C/min, from 25
to 550 °C.
Synthesis of HEC- cinnamates (HEC-Cin)
(i) Synthesis with cinnamic acid: Esterification of HEC
with cinnamic acids was carried out analogically as the
methods used for esterification of dextran [5] as well as
for esterification of HEC with higher fatty acids [2].
HEC (0.5 g) was dissolved in 25 ml dry DMSO under
stirring at room temperature for 2 h. Cinnamic acid (0.52 g) dissolved in DMSO (10 ml) was added to the
reaction mixture under permanent stirring. Then DCCI
(1.3 g) as activator of carboxylic acid and 4-DMAp as
catalyst (0.05 g) were added to the mixture and the
reaction continued at 50 °C for 0.5 h. After reaction, the
product was poured into 4-6 volumes of acetone and the
precipitated derivative was separated by filtration,
thoroughly washed with acetone (3 times), and extracted
in a Soxhlet apparatus with acetone for 20 h to remove
the unreacted acylation agent and degradation products.
(ii) Synthesis with cinnamoyl chloride: Esterification of
HEC with cinnamoyl chloride (ClCA) was carried out
analogously to esterification with cinnamic acid at
90° C and time 3 hours. The reaction was performed in
DMF (15 ml), pyridine (2-4 ml) and 4-DMAp (0.05 g).
The mass ratio of HEC to ClCA was 1:6. The recovery
and purification of the ester was the same as described
in the method (i).
Results and discussion
The HEC cinnamates were prepared by esterification of
HEC with cinnamic acid (CA) via in situ activation of
the carboxylic groups with DCCI as well as by classical
esterification method with cinnamoyl chloride (ClCA).
Prepared cinnamic esters under various reaction
conditions were dissolved in water and characterized by
FT-IR and UV spectroscopy. The reaction conditions
and yield of HEC-Cin derivatives are summarized
in tab. 1.
As can be seen from fig. 1 and tab. 1, FT-IR and UV
spectroscopy confirmed the preparation of HECcinnamates.
Tab. 1 Reaction conditions, yield and characteristic of HEC cinnamates prepared with CA activated by DCCI and with ClCA under
various reaction conditions
Tab. 1 Reakčné podmienky, výťažky a vybrané spektrálne dáta HEC-Cin derivátov pripravených modifikáciou s kyselinou škoricou
aktivovanou DCCI a s chloridom kyseliny škoricovej za rôznych reakčných podmienok
a
HEC:CA:DCCI 1:1:0.1
Reaction
medium
DMSO
Time
(h)
0.5
Temperature
(°C)
50
Yield
(g/g)a
0.94
Soluble in
H2O 0,1%
+
λmax
(nm)
281
HEC-Cin2
HEC:CA:DCCI 1:2:2
DMSO
0.5
50
0.98
+
280
HEC-Cin3
HEC:CA:DCCI 1:3:0.1
DMSO
0.5
50
0.86
+
280
HEC-Cin4
HEC:ClCA 1:6
DMF/pyridine
3
90
0.86
+
280
Sample
Mass ratio
HEC-Cin1
Expressed as g of the recovered derivative per g HEC (on dry mass basis).
The FT-IR spectra of HEC-Cin derivatives displayed
the absorption bands at ~1700 – 1716 cm-1 attributed to
the υ(C=O) vibration of the ester function (fig. 1). The
shift from a more typical absorbance at 1730 cm-1 is
attributed to the double bond conjugated with the
aromatic ring structure. FT-IR spectra showed bands at
1635 cm-1 which belongs to the C=C bonds as well as
bands at ~ 770 cm-1 attributed to the aromatic rings and
it is in accordance with literature [5]. The spectra also
showed increased intensities of the absorption band at
~ 2973 cm-1 and 2873 cm-1, respectively, attributed to
the νas(CH2) and νs(CH2) vibrations of the introduced
substituents. For further characterization and confirmation
of HEC functionalization by cinnamic acid or
cinnamoyl chloride the UV spectroscopy was used. The
spectra of the HEC esters exhibit the same absorbance
characteristic as the cinnamic acid (not shown). An
intense absorbance at ~ 280 nm is characteristic for the
vinylene C=C absorbance of the cinnamate group [6].
However the unmodified HEC does not show any
distinct absorbance in the UV region. FT-IR and UV
spectra date indicated that derivative HEC-Cin3 gives
higher extend of substitution than HEC-Cin4.
Some of the objectives of this work were connected
with the evaluation of the thermal properties for the
prepared HEC-Cin derivatives by TGA method. Results
from TGA analysis of selected HEC-Cin derivatives and
HEC are showed in tab. 2.
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Materiálové inženýrství
Material Engineering
higher substituted HEC-Cin with the aim to confirm
supposed higher thermal stability.
Conclusions
New water-soluble cinnamates of hydroxyethylcellulose
(HEC-Cin) were prepared by esterification of
hydroxyethylcellulose with cinnamic acid activated by
DCCI in DMSO and with cinamoyl chloride in
DMF/pyridine at various reaction conditions.
The obtained HEC-Cin derivatives were characterized
by FT-IR and UV spectroscopy. FT-IR and UV spectra
confirmed that HEC-Cin derivatives with low degree of
substitutions were prepared.
Fig. 1 FT-IR spectra of selected HEC-Cin derivatives and
unmodified HEC
Obr. 1 FT-IR spectra vybraných HEC-Cin derivátov
a nemodifikovanej HEC
Tab. 2 Results of thermal analysis of HEC cinnamates compared to HEC
Tab. 2 Výsledky termickej analýzy HEC-Cin v porovnaní s HEC
HEC-Cin2
Ton1
(°C)
257
Ton2
(°C)
385
HEC-Cin3
279
393
102.5
85
HEC
257.5
385
75.5
88
Sample
T10% weight Weight loss at
550 °C (%)
loss (°C)
76.0
88
HEC-Cin esters with smaller extent of esterification
have comparable thermal stability to HEC. Only
derivative HEC-Cin3 with higher degree of substitution
has a slightly higher thermal stability than HEC.
Derivative HEC-Cin3 and derivatives with higher
degree of substitution, which will be prepared in the
future, can be used in applied research in different areas
as antioxidants (e.g. in cosmetics, pharmaceutical).
Ton1 = onset of decomposition, Ton2 = onset of end decomposition.
Acknowledgement
This work was financially supported by the Slovak
Grant Agency VEGA, projects No. 2/0062/09.
Literature
[1] LANDOLL, L.M.: Nonionic polymer surfactants. Journal of Polymer
Science Part A: Polymer Chemistry, 1982, Vol. 20, p. 443-455
[2] SROKOVÁ, I., MINIKOVÁ, S., EBRINGEROVÁ, A.,
SASINKOVÁ, V., HEINZE, T.: Novel o-(2-hydroxyethyl)
cellulose - based Biosurfactants, Tenside Surfactants Detergents,
Vol. 40, 2003, p. 73-76
Fig. 2 TGA thermograms of HEC-Cin derivatives and unmodified HEC
Obr. 2 TGA krivky vybraných cinamátov HEC a HEC
The thermogravimetric plots of selected HEC-Cin
derivatives and HEC are given in fig. 2. Nevertheless,
the prepared esters showed small substitution with
cinnamoyl groups and some difference can be seen in
TGA curve. As observed, unmodified HEC has two
weight loss stages. The first at ~ 75.5 °C with weight
loss ~ 10 % is due to desorption of water and second
stage, appearing at higher temperature 257.5-385 is due
to HEC decomposition. The HEC-Cin derivatives show
two decomposition stages too. HEC-Cin2 with very low
extent of esterification exhibited Ton1 and Ton2
comparable to the unmodified HEC. However the HECCin3 exposed onset of the decomposition as well as
onset of the end decomposition at significantly higher
temperature. It is necessary to solve the preparation of
[3] MINIKOVÁ, S., SROKOVÁ, I., SASINKOVÁ, V.,
MALOVÍKOVÁ, A., EBRINGEROVÁ, A.: O-(2-Hydroxyethyl)
Cellulose-dervived Surfactants Prepared by Microwave -assisted
Transesterification, Tenside Surfactants Detergents, Vol. 46, No.
3, 2009, p. 163-168
[4] SROKOVÁ, I., KOSTELANSKÁ, K., RYCHLÁ, L.,
EBRINGEROVÁ, A., CSOMOROVÁ, A.: New Cinnamic Acid
Estres of Various Polysaccharides and Their Solutions and
Antioxidative properties. Modern Polymeric Materials for
Environmental Applications, Vol. 4, 2010, p. 141-146
[5] WONDRACZEK, H., KOTIAHO, A., FARDIM, P., HEINZE, T.:
Photoactive polysaccharides. Carbohydrate Polymer, 2011, Vol.
83, p.1048-1061
[6] GUPTA, P., TRENOR, S.R., LOMG T.E., WILKES, G.L.: In Situ
Photo-Cross-Linking
of
Cinnamate
Functionalized
Poly(methylmethacrylate-co-2-hydroxyethyl acrylate) Fibers during
Electrospinning, Macromolecules, 2004, Vol. 37, p. 9211-9218
Review: doc. Mgr. Ivan Kopal, PhD.
doc. Ing. Iva Sroková, CSc.
39
Materiálové inženýrství
Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Effect of Surfactant on Mechanical Properties of Polymer Blends
Vplyv povrchovo aktívnej látky na mechanické vlastnosti polymérnych zmesí
Ing. Petra Skalková, PhD., Faculty of Industrial Technologies, University of Alexander Dubček in Trenčín,
I. Krasku 491/30, 020 01 Púchov, Slovakia, Ing. Jaroslava Michálková, Vitrum Laugaricio – Joint Glass Center of
IIC SAS, TnU AD, FCHPT STU and RONA, j.s.c., Študentská 2, 911 50 Trenčín, Slovakia
Immiscible polymers are often blended together in the melt state to obtain a material with a desired set of
properties. The properties of such a blend depend on the properties of the constituents, as well as on the
morphology of the multiphase structure; generally the desired properties are achieved only by specific
morphologies. The interaction between sodium dodecyl sulfate (SDS) and blends of low density polyetylene (LDPE)
with galactomannane Locust Bean Gum (LBG) is discussed. The mixtures of polymer with surfactant have important
properties for a wide range of industrial application fields such as floatation processes, foaming control,
detergency, and enhanced oil recovery. Among all the mixed systems of polymer with surfactant, sodium dodecyl
sulfate (C12H25SO4Na) is the most used anionic surfactant.
Biodegradovateľné plastové materiály predstavujú novú generáciu materiálov, ktorých hlavnou prednosťou je
skutočnosť, že ich celý životný cyklus sa orientuje na ochranu životného prostredia a zdravia obyvateľstva. Cieľom
je postupne nahradiť v niektorých aplikáciách doteraz hromadne vyrábané a používané produkty z plastov,
predovšetkým z polyolefínov. Problémom je však odlišná štruktúra syntetických a prírodných polymérov, ktorá
spôsobuje vzájomnú nemiešateľnosť a s tým súvisiace nedostatočné úžitkové vlastnosti konečných výrobkov. Tento
negatívny fakt je možné odstrániť pridaním tretej zložky s vhodnými vlastnosťami, akými sú napr. tenzidy
a kompatibilizátory. Práca sa zaoberá prípravou a štúdiom zmesí nízkohustotného polyetylénu a galaktomanánu
Locust Bean Gum(LBG) s DS 0,28 v štyroch rozdielnych množstvách (5, 10, 15, 25 hm. %) za a bez prítomnosti
tenzidu- dodecyl sulfát sodný (SDS). Tenzid SDS sa použil v troch rôznych množstvách (10, 25, 50 hm. %) vzhľadom
na obsah LBG. Kompatibilita pripravených filmov sa študovala ATR spektroskopiou. Sledoval sa vplyv biopolyméru
LBG a tenzidu SDS na mechanické vlastnosti pripravených zmesí. Trojzložkové zmesi LDPE/LBG a SDS sa
vyznačovali lepšími mechanickými vlastnostmi ako nekompatibilizované zmesi.
polysaccharide in synthetic polymer blends, is to use
a compatibilizer (or surfactant) containing groups
capable of hydrogen bonding with polysaccharide
hydroxyls.
The field of synthetic polymer blends, has experi-enced
an enormous growth in size and sophistication over the
past three decades in terms of both the scientific base
and application, summarized in several publications
[1-5]. A thorough review of biopolymeric blends and
composites and thein applications in various industries
is also available [6]. The aim of bioartificial blending is
to produce man-made blends that confer unique structural
and mechanical properties on the base of the specific
properties of natural polymers and synthetic polymers. In
general biopolymers are more expensive than synthetic
polymers, but natural polymers are abundant and some
may be obtained at a relatively low cost.
Experiment
Materials
The low density polyethylene (LDPE) was used from
Slovnaft Petrochemicals, appropriate for packing
application. Sodium dodecyl sulfate (SDS) was supplied
from Aldrich. Galactomannan - Locust Bean Gum
(LBG) with DS = 0.28 was supplied from Aldrich.
Polymer blending is a convenient and attractive route
for obtaining new polymeric materials. Comparing with
the development of a novel homopolymer via the
synthesis of a newmonomer, making blends of currently
available homopolymers offers significant savings in
time and cost, and the blend properties may be tuned by
changing the composition [7]. However, this approach
is complicated by the fact that polymer blends are
generally thermodynamically immiscible [8]. Thus,
achieving compatibilization of immiscible polymer
blends has been a long-standing academic and
technological challenge. One approach to increase
compatibility, and thus the incorporated amount of
Melt-blending
Polysaccharide LBG was melt-blended with LDPE in
Brabender Plasti – Corder PLE 331. Mixing was
performed at 140 °C and 80 rpm for 15 min. For
LDPE/LBG blends, four different levels of
polysaccharide were used, namely 5, 10, 15 and 25 wt.
%. SDS was used as compatibilizer at three different
amounts, namely 10, 25 and 50 wt. % based upon
polysaccharide.
40
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Ma teriálové inženýrství
Material Engineering
ATR Measurements
ATR spectra were acquired in NICOLET 6700, with
DTGS detector and OMNIC 3.2 software (Thermo
Fisher Scientific, Madison, U.S.A) 128 with 4 cm-1
resolution.
Mechanical Properties of Blends
Measurements of the mechanical properties such as
tensile strength and elongation at break were performed
according to the Instron Corporation Material Testing
System 1.04. Measurements were done using
a 5 mm/min crosshead speed. Five measurements were
conducted for each sample, and the results were
averaged to obtain a mean value.
Fig. 2 ATR spectra of LDPE/LBG blends with different amount
of LBG and 50 wt. % of SDS
Obr. 2 ATR spektrá LDPE/LBG zmesí s rôznym obsahom LBG
a 50 hm. % tenzidu SDS
Results and discussion
SDS is an anionic surfactant used in many cleaning and
hygiene products. The salt is of an organosulfate
consisting of a 12 carbon tail attached to a sulfate group,
giving the material the amphiphilic properties required
of a detergent.
Fig. 1 Structure of SDS [9]
Obr. 1 Štruktúrny vzorec SDS [9]
Presence of surfactant SDS in blends of polyolefine and
polysacharide is showed on changes in spectra (fig. 2).
Band at 1466 cm-1 appears to δ vibrations of C-H etheric
bond, band at 721 cm-1 appears to ρ vibrations of methyl
groups. A both confirm presence of surfactant SDS in
LDPE/LBG blends. The presence of surfactant SDS is
confirmed by area around 1078 to 989 cm-1, that appears
ṽsym and ṽasym vibrations of S-O groups and ṽsym of
carboxylic groups, too.
Fig. 3 Tensile strength of SDS compatibilized LDPE/LBG blends
in dependence on LBG content
Obr. 3 Pevnosť v ťahu SDS kompatibilizovaných LDPE/LBG zmesí
v závislosti od obsahu LBG
Degree of compatibility of polymer blends is monitored
in a range from totally miscible systems to phase
separation. Compatibility is a function of polymeric
molecules interactions in blend and can be studied by
means of various methods including mechanical and
interfacial measurements [11]. In compatible blends,
mechanical properties such as tensile strength and
Young’s modulus show linear functionality vs. blend
composition.
SDS surfactant is able to form stable complex with
polysaccharide and polyethylene as a result of bonds
between alkyl groups of surfactant and hydroxyl groups
of polysaccharide [10].
Fig. 4 shows elongation at break of measured
LDPE/LBG blends with varying amount of surfactant
SDS. Addition of surfactant has positive effect,
especially in case of blends with 5 and 10 wt. % of
LBG. The highs improvement was recorded in case of
blend with 50 wt. % of SDS.
Fig. 3 shows tensile strength of SDS compatibilized
LDPE/LBG blends. It is obvious that with increasing
amount of LBG tensile strength decreases. Addition
of surfactant SDS 10 wt. % has positive effect on
tensile strength.
Similar as tensile strength, elongation at break decreases
with increasing content of LBG.
41
Materiálové inženýrství
Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
To improve compatibility between two immiscible
polymers, SDS surfactant was used. Addition of
10 wt. % of SDS has positive effect on tensile strength.
In synthetic blends, addition of another immiscible
phase into tough matrix causes sharp decrease of
elongation at break. Addition of surfactant has positive
effect in case of blends with 5 and 10 wt. % of LBG and
50 wt. % of surfactant SDS.
Young’s modulus of LDPE/LBG blends without
surfactant decreases moderately with increasing amount
of LBG. On the contrary, in case of presence of
surfactant SDS in blends Young’s modulus rises.
Literature
[1] COOMBES, A.G.A., VERDERIO, E., SHAW, B., LI, X.,
GRIFFIN, M., DOWNES, S. Biocomposites of non-crosslinked
natural and synthetic polymers, Biomaterials 23, 2002, p. 2113–
2118
Fig. 4
Elongation at break of SDS compatibilized LDPE/LBG
blends in dependence on LBG content
Obr. 4 Závislosť ťažnosti od množstva LBG v zmesi s LDPE
s meniacim sa množstvom tenzidu SDS
[2] MARSANO, E., VICINI, S., SKOPINSKA, J., SIONKOWSKA, A.
Chitosan and poly(vinylpyrrolidone): kompatibility and miscibility of
blends, Macromolecular Symposia 218, 2004, p. 251–260.
Generally, Young’s modulus is closely associated with
material rigidity. Blending of natural polymer into
polyethylene leads to higher standard deviations of
Young’s modulus compared to monodispersive systems.
This is caused either by surfactant SDS or by the
presence of filler (LBG). Blends with 0, 10 wt. % and
25 wt. % of surfactant and above 10 wt. % of LBG filler
show decreasing tendency of Young’s modulus.
[3] KOŠTIAL, P., RUŽIAK, I., JONŠTA, Z., TVRDÝ, M.
Experimental Method for Complex Thermo-mechanical Material
Analysis, International Journal of Thermophysics 31, 2010,
p. 630-636
[4] SIONKOWSKA, A. Interaction of collagen and poly(vinyl
pyrrolidone) in blends, European Polymer Journal 39, 2003,
p. 2135–2140
[5] SKALKOVÁ, P., ČÍŽOVÁ, A., JOCHEC-MOŠKOVÁ, D.,
JANIGOVÁ, I. LDPE/glukuronoxylan blends: Preparation and
study of thermal and mechanical properties, Cellulose Chemistry
and Technology 46, 2012, p. 69–77
[6] SIONKOWSKA, A., WISNIEWSKI, M., SKOPINSKA, J.,
KENNEDY, C.J., WESS, T.J. The photochemical stability of
collagen-chitosan blends, Journal of Photochemistry and
Photobiology A 162, 2004, p.545–554
[7] ADEDEJI, A., LYU, S., MACOSKO, C.W. Block copolymers in
homopolymer blends: Interface vs. micelles, Macromolecules 34,
2001, p. 8663–8668
[8] ANDERSON, K.S., HILLMYER, M.A. The influence of block
kopolymer Microstructure on the Toughness of Compatibilized
Polylactide/polyetylene Blends, Polymer 45, 2004, p. 8809–8823
[9] BRUCE, CH.D., SENAPATI, S., BERKOWITZ, M.L., PERERA,
L. Molecular Dynamics Simulation of Sodium Dodecyl Sulfate
Micelle in Water: Micellar Structural Characteristics and
Counterion Distribution, Journal of Physical Chemistry B 106,
2002, p. 10902–10907
Fig. 5 Young’s modulus of SDS compatibilized LDPE/LBG blends
in dependence on LBG content
Obr. 5 Závislosť Youngovho modulu od množstva plniva v zmesi
LDPE/LBG za a bez prítomnosti tenzidu SDS
[10] RODRIGUEZ-GONZALES, F.J., RAMSAY, B.A., FAVIS, B.D.
High
performance
LDPE/thermoplastic
starch
blends:
A sustanaible alternative to pure polyetylene, Polymer 44, 2003,
p. 1517–1526
Conclusions
[11] PAUL, D.R., BUCKNALL, C.B. Polymer Blends, Vol. 1, New
York: Wiley Interscience, 1–14, 2000
Tensile strength and elongation at break of blends
without surfactant decrease with increasing content of
filler (LBG). This decrease is caused by inhomogenity
of prepared blends.
Review: prof. Ing. Darina Ondrušová, PhD.
doc. RNDr. Mariana Pajtášová, PhD.
42
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ISSN 0018-8069
Materiálové inženýrství
Material Engineering
The Influence of Non-aromatic Oils on the Properties of Winter Tread
Compounds
Vplyv nearomatických olejov na vlastnosti zimných behúňových zmesí
doc. RNDr. Mariana Pajtášová, PhD., Ing. Jana Paliesková, Ing. Andrea Feriancová, Ing. Zuzana Jankurová,
prof. Ing. Eugen Jóna, DrSc., Faculty of Industrial Technologies, University of Alexander Dubček in Trenčín,
I. Krasku 1809/34, 020 01 Púchov, Slovakia
The subject of this work was to ivestigate the effect of enviromental plasticizer on tyre tread compounds for winter
application. Plasticizers are very important for rubber compounds. These are the ingredients decreasingf stiffness of
the rubber compounds and thus regulating its workability. In rubber industry the most commonly used plasticizer is
based on oil origin. These oils are dividend into high-aromatic oils, relatively aromatic, naphtenic, relatively
naphtenic and paraffinic oils. Use of high aromatic oils in rubber industry is criticized because they contain polycyclis
aromatics (PCA), most of which are carcinogenic. The influence of ecological plasticizers is investigated in this paper.
Using ecological plasticizers TDAE, MES and RAE the rubber compounds were prepared and they were compared to
the compound with DAE. The following rubber compounds were tested from the aspekt of physical-mechanical
properties and vulcanization characteristics. The measured results led to conclusion that some of properties of winter
tread compounds were improved by application of ecological and commercial available plasticizers.
Práca sa zaoberá skúmaním vplyvu nearomatických olejov na fyzikálno-mechanické vlastnosti vulkanizátov, ako aj
na vulkanizačné charakteristiky behúňovej zmesi určenej na zimné použitie. Jednalo sa o oleje typu TDAE,
MES, RAE. Vlastnosti pripravených zmesí s obsahom uvedených zmäkčovadiel boli porovnávané so štandardnou
behúňovou zmesou, v ktorej bol ako zmäkčovadlo použitý vysokoaromatický olej typu DAE. Z nameraných výsledkov
pre zimné behúňové zmesi vyplýva, že pri stanovení vulkanizačných charakteristík pri teplote 150 °C, všetky zmesi
dosiahli požadované hodnoty optimálnej doby vulkanizácie. Pri stanovení fyzikálno-mechanických vlastností
a hodnotenia výsledkov ťažnosti, pevnosti, modulov pri 100%, 200%, 300%-nom predĺžení a tvrdosti pri 23 °C
vyplýva, že namerané hodnoty sú porovnateľné so štandardnou zmesou. Najvyššie hodnoty pevnosti dosahovala
zmes, v ktorej bol aplikovaný ekologický olej TDAE. Vysoké hodnoty tvrdosti vulkanizátov pri nízkych teplotách
znižujú trakciu plášťov na ľade a zasneženej vozovke. Je dôležité sledovať nárast tvrdosti pri 7 °C, pretože sa pri nej
začínajú výrazne meniť vlastnosti vulkanizátov. U štandardnej zmesi s použitím oleja DAE sa zaznamenal najväčší
nárast hodnôt tvrdosti pri 7°C. Pri variante s použitím parafinického oleja MES boli namerané najnižšie hodnoty
tvrdosti pri 7 °C, čo je dôležitý parameter pre zimné behúňové zmesi. Na základe získaných výsledkov možno
konštatovať, že s aplikáciou ekologických a komerčne vyrábaných zmäkčovadiel typu TDAE, MES, RAE do
behúňových zmesí určených na zimnú prevádzku sa zlepšili niektoré sledované vlastnosti vulkanizátov.
Plasticizers are an integral part of the rubber
compounds. These are the ingredients for dwindling
strength of the rubber compounds, in addition to
adjusting the processing characteristics of rubber
compounds and they also affect the properties of
vulcanizates for which it is mainly connected with the to
improvement of the physical-mechanical and dynamicmechanical properties [1].
friendly replacement high-aromatic oils. There are
different criteria for replacement of high-aromatic oils,
mainly includes a defined chemical structure, physicalchemical properties identical to DAE, the same
compatibility with the rubber compound and economic
aspects of production and sales [3].
The current trend towards to use of ecologic or
naphthenic type oils. The category of ecological oils
seem like the best replacement type TDAE oil-treated
distillate aromatic oils, MES-refined oil extraction and
RAE-residual aromatic oils [5]. The main benefits of
using organic type plasticizers TDAE, MES and RAE
are mainly connected with the fact that they meet safety
criteria as well as they are non-carcinogenic and their
manufacturability is easy in refineries. Physicalmechanical,
dynamic-mechanical
properties
of
vulcanizates and curing characteristics are very useful
means of assessing the properties of the rubber
compounds.
From the technological point of view, in the rubber
industry they are proved to be very high aromatic oils
[2]. High-aromatic oils falls under the name of the DAE
- distillate aromatic extract and dissolution are formed
as products of extraction, which is a step in refining the
standard neutral lubricating oil [3]. The use of higharomatic oils in the rubber industry is increasingly
criticized, particularly because of health risks, because
these oils contain polycyclic aromatics (PCA), most of
which are carcinogenic [4]. It is therefore necessary to
replace these types of plasticizers and look for new eco43
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Materiálové inženýrství
Material Engineering
The aim of the present study was to investigate the
effects of environmental plasticizers on curing
characteristics of tread compounds and physicalmechanical and dynamic-mechanical properties of
vulcanizates. In all measurements the tested mixtures
compared were with standard comparative mixture,
which was applied as a type of plasticizer of higharomatic oils DAE.
Curing period for each test mixture was determined
according to the value (ts) and it the highest for mixture
(B) with oil RAE. All of the blends have the lower value
of torque (MH) than the model mixture (M) with higharomatic oil DAE. All mixtures had approximately the
same value of the optimum cure time (t90) as a model
compound (M).
Physical-mechanical properties
Experiment
The values of the physical-mechanical properties of
vulcanizates are necessary for determination of the
processing properties of finished rubber products. Test
specimens are carved from plates of vulcanized mixture.
The results of measurements are given in tab. 2 and
figures 1 and 2.
Individual rubber mixtures were prepared according to
precise formulas. The high-aromatic plasticizer of type
DAE and ecological plasticizers of type: RAE, MES,
TDAE t were blended with the model compound.
All mixtures were prepared by mixing in multistage
laboratory blender Farrel BR Banbury 1600 [7]. Curing
characteristics of the mixtures were measured by
Rheometer MDR 2000E from Monsanto at 150 °C [8].
Physical-mechanical properties (tensibility, tensile
strenght, modulus 100, 200, 300) were investigated on
TESTOMETER 10 MONSANTO. Used test specimens
had the shape of two-sided blades with a thickness of
2 mm [9]. Hardness was measured by HARDNESS
SHORE A and test specimens are shaped ring and must
have a thickness of 6 mm [10]. Dynamic-mechanical
properties (temperature embrittlement of rubber) are
measured on the device, the main parts of which are:
clamping mechanism, bumper, cooling chamber with
stirrer and glass thermometer. Test specimens had the
shape of a strip with a thickness of 2 mm [11].
Tab. 2 Physical-mechanical properties of vulkanizates
Tab. 2 Fyzikálno-mechanické vlastnosti vulkanizátov
Tensibility[%]
Tensile strength
[MPa]
M300 [MPa]
Hardness 23°C
[ShA]
Hardness 7°C
[ShA]
16,5
16
14,5
Model compound was prepared on the basis of natural
rubber (SMR 20) and synthetic rubbers (BR, S-SBR)
and high-aromatic oil of type DAE (M) was used as
a platicizer. Into the base compound, each type of
ecological plasticizers of type TDAE (A), RAE (B),
MES (C) is used in varying amounts. Curing
characteristics of all compounds were measured at
150 °C. The curing characteristics were measured from
the course of vulcanization curves and they are:
maximum torque (MH), minimum torque (ML), starting
time (ts) and optimum cure time (t90) of rubber. Their
values are given in tab. 1.
C
(MES)
617
15.19
16.06
15.71
15.32
6.15
6.19
5.97
5.76
62.5
61.2
59.6
58.9
63.4
63.1
62.7
61.4
TDAE
B
(RAE)
15.60
2.47
7.99
24.88
5.92
DAE
RAE
MES
14
M
A
B
C
Fig. 1 Tensile strength of vulkanizates
Obr. 1 Pevnosť v ťahu vulkanizátov
Determination of physical-mechanical properties and
performance assessment of tensibility, strength,
modulus 100, 200, 300 and hardness 23 °C, led to the
achievement of comparable values with the standard
mixture.
Tab. 1 The individual values of vulcanization characteristics
Tab. 1 Hodnoty vulkanizačných charakteristík
MH[N.m]
ML[N.m]
tS [min]
t90 [min]
RV [min-1]
B
(RAE)
626
Tensile strength
15
Curing characteristics
A
(TDAE)
16.19
2.59
9
23.59
6.85
A
(TDAE)
627
15,5
Results and discussion
M
(DAE)
17.1
2.96
7.93
23.80
6.30
M
(DAE)
584
The carrier truck mixtures for use at low temperatures
must be monitored from the aspect of hardness at 7 °C.
Temperature around 7 °C is important because this is the
temperature when the properties of vulcanizates start to be
modified substantially. Variants using ecological oil MES
had the lowest measured value of hardness s at 7 °C.
C
(MES)
14.36
2.23
8.71
24.72
6.25
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Material Engineering
Acknowledgement
This work was supported by a grant VEGA
1/0530/11.
Hardness 7°C
Literature
DAE
TDAE
RAE
M
A
B
[1] PREKOP, Š., VÁRKOLY, L., KUČMA, A., ĎURIŠ, Š.,
FEDOROVÁ, E., MATUŠČINOVÁ, A., MICHÁLEK , J.
Gumárska technológia I., University of Žilina, 1998
MES
[2] MEJSTŘÍK, V., DRŽKOVÁ, L., SÁGNER, Z., MATRKA, M.,
KAMPERA, F. Chemické listy 81, 357, 1987
C
[3] API Publication 1509, 14. Edition, American Petroleum institute
Fig. 2 Hardness 7 °C of vulkanizates
Obr. 2 Tvrdosť vulkanizátov pri 7 °C
[4] International Agency for Research on Cancer: Mineral oils. In:
IARC Monographs on the Evaluation of the Carcinogenic Risk of
Chemicals to Humans, Vol. 33, 1984, p. 148
Conclusions
[5] NULL, V. Safe Process Oils for Tires with Low Environmental
Impact, Kautchuk Gummi Kunststoffe, 52, no.12, 1999
The objective of this work was to investigate the effect
of ecological plasticizers of type TDAE, MES and RAE
as replacing agents of high-aromatic oils DAE on the
processing properties of tread compound. It was also
connected with investigation of their influence on the
curing characteristics of compounds and physicalmechanical properties of the vulcanizates.
[6] GAM Matador a.s. Púchov 2006. [CD-Rom]
[7] STN 62 1425 - Preparation and curing of rubber mixtures
[8] STN 62 1416 – Determination of curing characteristics
[9] STN 62 1436 – Determination of tensile properties
[10] STN 62 1431 – Determination of hardness
Review: prof. Ing. Darina Ondrušová, PhD.
prof. Ing. Tatiana Liptáková, PhD.
Based on the obtained results it can be concluded that
the application of a commercially produced organic
plasticizers of type TDAE, MES, RAE to tread
compound for winter application improved some of
properties of vulcanizates.
_____________________________________________________________________________________________
Ostravské hutě vyrábějí potrubí pro polský plynovod
Infoprostor.cz
3.12.2012
Potrubí pro polský plynovod budou ostravské hutě vyrábět v následujících 3 letech. ArcelorMittal Tubular
Products Ostrava (AMTPO), dceřiná společnost ArcelorMittal Ostrava, uzavřela významnou zakázku s
polským distributorem plynu GAZ System. Jedná se o konstrukci páteřní sítě plynovodů v Polsku, na
které se AMTPO bude podílet minimálně jednou třetinou objemu dodávek spirálově svařovaných trubek.
„Jsem rád, že naše výrobky svou kvalitou obstály ve velké konkurenci. V rámci tohoto projetu jsme již
dodali do Polska celkem 27 kt spirálně svařovaných trubek o průměru 711 mm ve speciální jakosti. Jedná
se o technicky náročný sortiment s množstvím požadavků na kvalitu nad rámec obvyklé normy,“ uvedl
Otto Mischinger, generální ředitel společnosti AMTPO.
Před předložením nabídky do výběrového řízení AMTPO úspěšně prošla náročným předkvalifikačním
procesem, kde nakonec z důvodu vysokých požadavků na kvalitu uspěla jen tři konsorcia firem. AMTPO
je spolu s dalšími dvěma polskými partnery členem konsorcia, které garantuje splnění všech náročných
finančních, komerčních i technických podmínek dodávek do polského plynárenství. Na celkovém
množství 694 km plynovodního potrubí (132 kt) se bude AMTPO podílet svými dodávkami v rozmezí tří
let. Do současné doby už bylo dodáno 145 km (27 kt) potrubí.
Za výstavbu a provozování terminálu na zkapalněný zemní plyn v polském přístavu Świnoujście
zodpovídá polská společnost GAZ System.
Jistě není bez zajímavosti, že v loňském roce se AMTPO podílela na výstavbě plynovodu STORK,
vedoucího od podzemního zásobníku v Třanovicích k česko-polské hranici.
SB
45
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Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Influence of Various Fillers on Physical and Mechanical Properties of Model
Rubber Compounds
Vplyv rôznych plnív na fyzikálno–mechanické vlastnosti modelových
gumárenských zmesí
doc. RNDr. Mariana Pajtášová, PhD., Ing. Zuzana Jankurová, prof. Ing. Eugen Jóna, DrSc., Ing. Katarína
Holcová, Ing. Jana Paliesková, Ing. Mária Kopcová, Faculty of Industrial Technologies, University of Alexander
Dubček in Trenčín, I. Krasku 1809/34, 020 01 Púchov, Slovakia
The given paper deals with study and preparation of various non-conventional fillers which were selected in the
order to substitute specific amount of conventional active filler in model rubber compounds. The four different types
of fillers were examined. These investigated non-conventional fillers included dry matter from coffee waste, fabric
from waste degradation of tire, monoionic Ca2+ form and monoionic Co2+ form of clay mineral – montmorillonite.
The paper is closely connected with measurement of vulcanization characteristics (minimum torque ML, maximum
torque MH, time of start of vulcanization ts, optimum time of vulcanization tc90, rate coefficient of vulcanization Rv)
and evaluation of the measured data in relation to non-vulcanized model rubber compounds. Moreover, the physical
and mechanical properties (tensile strength, modulus 300, tensibility) of resultant vulcanizate were investigated. All
these properties were compared to properties of standard filler used in the rubber industry while this standard filler
was highly reinforcing carbon black of type N660.
Práca sa zoberá skúmaním možnosti zapracovania rôznych látok vo funkcii plniva do gumárenských modelových
zmesí. Pre funkciu plniva do modelových gumárenských zmesí boli zvolené 4 rôzne typy látok (sušina z kávového
odpadu, tkanina z odpadov degradácie pneumatík, monoiónová Ca2+ a Co2+ forma ílového minerálu –
montmorillonitu), ktoré boli pridávané v množstve 1 dsk a 5 dsk. Vo všetkých modelových gumárenských zmesiach
bol použitý typ plniva kombinovaný so štandardne používaným aktívnym plnivom (sadze typu N660). Pre funkciu
porovnávacej zmesi bola zvolená štandardná gumárenská zmes s obsahom sadzí, pripravená za rovnakých
podmienok ako všetky modelové gumárenské zmesi. U výsledných vulkanizátov, pripravených v tvare obojstranných
lopatiek boli hodnotené vulkanizačné charakteristiky (minimálny krútiaci moment ML, maximálny krútiaci moment
MH, začiatok vulkanizácie ts, optimálny čas vulkanizácie tc90, koeficient rýchlosti vulkanizácie Rv) a fyzikálnomechanické vlastnosti (pevnosť v ťahu, modul 300, ťažnosť, tvrdosť) v zmysle platných noriem. Z výsledkov vyplýva,
že je možné použitie vybraných odpadových a prírodných látok do gumárenských zmesí, aj vo funkcii plniva,
nakoľko sú schopné pozivívne ovplyvňovať fyzikálno-mechanické vlastnosti študovaných vulkanizátov.
Fillers are important ingredients in rubber compounds
that have significant affect on properties of compounds
and product and there is possibility to modify or adjust
the quality as well as quantity of these fillers in an
extensive way. Mostly they are solid substances used in
form of powder or short fibers. Fillers help to improve
the mechanical properties (such as strength, abrasion
resistance, toughness, stiffness) and they also improve
the resistance to heat, fire, corrosion, aging as well as
they affect the appearance of products [1]. Efficiency of
fillers depends on the various parameters including the
size of the filler particles, their shape, dispersion and
surface, surface reactivity, structure of filler, ability
of filler to form bonds with the rubber matrix [2].
model rubber compounds were prepared of two-step
mixing in laboratory mixer of type Brabender, and the
procedure was done according to STN (Slovak
Technical Standard) [3]. The first step is connected with
the preparation of base compounds and following
addition of different fillers while the temperature was
120°C. Base compounds included natural rubber SMR20, carbon black of type N660, dry matter from waste of
coffee SC (particle size is less than 0.2 mm), fabric from
waste of degradation tire CH, monoionic Ca2+ form CaI
(particle size is less than 0.063 mm) and monoionic
Co2+ form CoI (particle size is less than 0.063 mm)
of clay mineral – montmorillonite, activator of sulfur
vulcanization – ZnO, stearic acid. Mixing relating to the
first step took 12 minutes. In the second step, it was at
the temperature 90°C, components of vulcanization –
accelerator
N-cyklohexyl-2-benzothiazolsulfenamid
(CBS) and vulcanization agent sulfur were added to the
base compounds. The mixed model rubber compounds
were homogenized in first and second steps in
Experiment
Preparation and mixing of rubber compounds is one of
the most important processes of rubber technology. The
46
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Materiálové inženýrství
Material Engineering
laboratory double-rolled device. Determination of
vulcanization characteristics was done by vulcameter
MONSANTO at the temperature 150°C during 60 min
recording of vulcanization curve, according to STN [4].
Tensile properties were determined by help of shredder
INSTRON, according to STN [5]. The evaluated
properties were tensile strength, modulus 300,
tensibility. Hardness of vulcanizate was measured by
hardness tester IRHD, according by STN [6]. The
measured values of model rubber compounds were
compared to standard rubber compounds.
Fig. 1 Maximum torque of resultant vulcanizate
Obr. 1 Maximálny krútiaci moment výsledných vulkanizátov
Results and discussions
The vulcanization characteristics of the model
rubber compounds
Effect of fillers (SK, CH, CaI, CoI ) on the course of
sulfur vulcanization of model rubber compounds was
evaluated on the basis of vulcanization characteristics
(minimum torque ML, maximum torque MH, time of
start of vulcanization ts, optimum time of vulcanization
tc90, rate coefficient of vulcanization Rv). Vulcanization
characteristics of the evaluated rheometric results of
vulcanization curves are summarized in tab. 1.
Graphical presentation of the results of determination of
vulcanization characteristics are shown in fig. 1, 2.
Fig. 2 Optimum time of resultant vulcanizate
Obr. 2 Optimálny čas výsledných vulkanizátov
During the measurement of optimum time (fig. 2) of
vulcanization of model rubber compound SK with
amount 5 phr, the highest value was observed in
comparison to standard compound and it which could
have a positive impact on the quality of the resulting
vulcanizate.
Tab. 1 Vulcanization characteristics of rubber compounds
Tab. 1 Vulkanizačné charakteristiky výsledných vulkanizátov
compound
SK
CH
CaI
CoI
S
1 [phr]
5 [phr]
1 [phr]
5 [phr]
1 [phr]
5 [phr]
1 [phr]
5 [phr]
ML
MH
ts
tc90
[N.M] [N.M] [min] [min]
10.7
75.4 5.8 9.7
11.2
75.8 5.6 9.6
10.9
74.6
7 11.1
11.5
77.1
6
9.6
13.7
77.3 5.9 9.3
11.8
76.3 6.7 10.9
14.9
76.7 6.6 10.4
13
78.3 6.3 10.4
12.1
73.9 6.3 9.6
Rv
[min-1]
25.6
25
24.4
27.8
29.4
23.8
26.3
24.4
30.3
The physical and mechanical properties of the model
rubber compounds
The selected physical and mechanical properties
(strength, modulus 300, tensibility) were tested and
evaluated in the case of the standard vulcanizate and
vulcanizates with content of fillers (SK, CH, CaI, CoI).
Effect of type and amount of filler on selected physical
and mechanical properties is presented in tab. 2.
Graphic image of the results for important physicalmechanical properties of vulcanizates are shown
in fig. 3, 4.
The values of maximum torque (fig. 1) for model rubber
compounds are higher in comparison to standard rubber
compound, except for compounds SK and CoI with
addition of 5 phr, which are lower significantly.
Tab. 2 Physical and mechanical properties of rubber compounds
Tab. 2 Fyzikálno-mechanické vlastnosti gumárenských zmesí
compound
The decrease of values of the maximum torque shows
lower stiffness as well as the viscosity of the
compounds at the end of vulcanization and it is
probably due to incompatibility of rubber matrix
with filler.
SK
CH
CaI
CoI
47
S
1 [phr]
5 [phr]
1 [phr]
5 [phr]
1 [phr]
5 [phr]
1 [phr]
5 [phr]
TS
[MPa]
27.47
24.55
20.88
24.13
20.57
27.40
26.84
26.59
25.20
M 300 Tensibility Hardness
[MPa]
[%]
[IRHD]
19.49
422.8
57.42
17.87
408.2
58.67
15.69
398.4
56.92
18.13
399.2
58.96
16.41
375.8
61.67
19.70
420.8
58.42
16.63
484.2
56.29
18.82
424
57.88
16.68
452.6
56.54
Materiálové inženýrství
Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Evaluation of measured tensile properties showed that
tensile strength (fig. 3) of added filler SK, CH with
amount 5 phr was lower significantly in comparison to
standard rubber compound.
Fig. 5 Tensibility of resultant vulcanizate
Obr. 5 Ťažnosť výsledných vulkanizátov
Conclusions
Fig. 3 Tensile strength of resultant vulcanizate
Obr. 3 Pevnosť v ťahu výsledných vulkanizátov
Vulcanization characteristics (minimum torque M L,
maximum torque MH, time of start of vulcanization ts,
optimum time of vulcanization tc90, rate coefficient
of vulcanization Rv) and physical mechanical properties
(tensile strength, modulus 300, tensibility) were
evaluated for resulting vulcanizates according to STN
and all the obtained results were compared to the
standard rubber compound.
The lower values of hardness (fig. 4) were measured for
model rubber compounds CaI and CoI with amounts
5 phr in comparison with standard compound and they
show good integration of filler into the compound and
good compatibility with the rubber matrix. The highest
hardness value was observed in the case of a model
rubber compound CH with amounts 5 phr.
According to the results, it could be concluded that
carbon black of type N660 can be replaced partially by
waste and natural materials, which can be used as fillers
in rubber compounds.
Acknowledgement
The authors are grateful to the Slovak Grant Agency
VEGA 1/0185/12 for financial support.
Literature
[1] DUCHÁČEK, V. Polymery - výroba, vlastnosti, zpracování,
použití, 2. vyd. VŠCHT Praha , 2006
[2] ČÍČEL B., NOVÁK I., HORVÁTH I.: Mineralógia
a kryštalochémia ílov. Veda Bratislava, 1981
[3] Príprava a vulkanizácia gumárenských zmesí STN 62 1425
[4] Stanovenie vulkanizačných charakteristík STN 62 1416
[5] Stanovenie ťahových vlastností STN 62 1436
[6] Stanovenie tvrdosti STN 62 143
Fig. 4 Hardness of resultant vulcanizate
Obr. 4 Tvrdosť výsledných vulkanizátov
The highest value of the tensibility (fig. 5)
in comparison with standard compound was observed
for model rubber compound CaI with amount 5 phr and
this compound has advantageous properties from the
aspect of elastic applications.
Review: prof. Ing. Darina Ondrušová, PhD.
prof. Ing. Tatiana Liptáková, PhD.
48
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Materiálové inženýrství
Material Engineering
Thermal and XRD Analysis of Intercalation Process of Kaoline with Dimetyl
Sulfoxide and CuII Ions
Termická a Rtg analýza kaolínu interkalovaného dimetylsulfoxidom
a iónmi CuII
doc. RNDr. Mariana Pajtášová, PhD., Ing. Andrea Feriancová, Ing. Jana Paliesková, prof. Ing. Eugen Jóna,
DrSc., Department of Material technologies and Environment, Faculty of Industrial Technologies, University of
Alexander Dubček in Trenčín, I. Krasku 1809/34, 020 01 Púchov, Slovakia.
In the present study natural kaoline from Kaznejov have been modified by intercalation with dimethyl sulfoxide and
treated by copper ions CuII. Intercalation is reversible process and may involve exchange of cations from interlayer,
adsorbtion of polar molecules through ion-dipole interactions, hydrogen bonding, and protonation. XRD analysis
demonstrated the formation of intercalate DMSO-kaoline due to increasing its basal spacing from 7.20 Å to
11.27 Å. The second step was the adjustment of CuII ions. Intercalated Cu-kaoline showed two new peaks 6.97 Å and
3.53 Å which are attributed to the compound containing CuII ions. This conclusion is confirmed also by thermal
analysis where an intense endothermic effect was observed at ~271 °C.
Kaolín je významná prírodná surovina používaná v rôznych odvetviach priemyslu. Jeho modifikáciou organickými
alebo anorganickými molekulami je možné získať nanomateriál s požadovanými vlastnosťami. Práca sa zaoberá
interkaláciou kaolínu dimetylsulfoxidom, ktorý môže byť dobrým vstupným agentom pre iné zlúčeniny, napr.
s obsahom ťažkých kovov. Interkalácia je vratný proces, ktorý môže prebiehať ako výmena katiónov z medzivrstvia
alebo ako adsorbcia polárnych molekúl cez ión-dipólové reakcie, vodíkový mostík a pod. Výsledky rtg a termickej
analýzy potvrdili naviazanie DMSO do štruktúry ílu. Interkaláciu potvrdil nárast hodnoty d001, kde u interkalátu
Kdmso došlo k zväčšeniu medzirovinnej vzdialenosti z 7,20 Å na 11,27 Å. Pri termickej analýze bol pozorovaný
výrazný termický efekt v rozpätí hodnôt 150 – 200 °C, ktorý zodpovedá rozpadu DMSO. Na modifikáciu interkalátu
Kdmso bol použitý Cu(NO3)·2H2O. Z nameraných výsledkov vyplýva, že pri reakcii interkalátu Kdmso s CuII iónmi
dochádza ku vzniku novej zlúčeniny s obsahom CuII iónov, ktorá je naviazaná do štruktúry kaolínu. Dva nové píky
6,97 Å a 3,53 Å potvrdzujú prítomnosť tejto zlúčeniny, resp. komplexu. Tento záver potvrdzuje aj termická analýza,
kde sa na DTA krivke prejavil intenzívny endotermický pík pri 271 °C.
Kaolin is a hydrated aluminum silicate from a group of
natural kaolinite – serpentine clays which have at least
one dimension in range of 1-100 nm. The layered
structure of kaolin consists of silica tetrahedral (SiO4)
units stacked together with gibbside octahedral (AlO6)
units. The layers are held together by hydrogen bonds
between the oxygens in one of the alumina octahedral
bonds between the oxygens on one layer and the
hydroxyl groups on the next layer [1-10]. The hydrogen
bonding between the adjacent layers prevents expansion
(swelling) of kaolin beyond its basal spacing of 7.20 Å.
This basal spacing can be expanded by incorporating
(intercalation)
organic/inorganic
compounds.
Intercalation is a reversible process and may involve
exchange of cations from interlayer, adsorbtion of polar
molecules through ion-dipole interactions, hydrogen
bonding, and protonation [2, 3]. The conditions employed
in the preparation of these materials depend on the
inorganic matrix. Advances in the preparation of hybrid
organic-inorganic materials by intercalation of organic
molecules into kaoline represented the possibility for
developing new and interesting materials [2-5].
DMSO may be used as an entraining agent for
intercalation of other compounds which cannot
otherwise be easily intercalated into kaolin for example
metal ions. The adsorbtion of metal ion onto clay
minerals in natural or chemically modified form is an
important process not only in soil chemistry but also in
rubber industry [6].
In the present study, natural kaoline from Kaznejov
have been modified by intercalation with dimethyl
sulfoxide and treated by copper nitrate. The clay
characteristic and the effect of the treatments were
examined by techniques of X-ray diffraction and by
thermogravimetry/differential
thermal
analysis
(DTA/TG).
Experiment
The kaolin sample used in this investigation was from a
natural deposit Kaznejov, and was used without further
treatment. Its chemical composition was 44.9 % SiO2,
47.49 % Al2O3, 3.34 % K2O, 1.45 % Fe2O3, 1.61 %
TiO2 and LOI (lost of ignition) 9.24 %. Chemicals for
chemical treatmen such as dimethyl sulfoxide (DMSO),
Cu(NO3)·2H2O, sodium hydroxide (NaOH) were
Organophillic cation such a dimethyl sulfoxide DMSO
can be used for modification of kaoline. Simultaneously
49
Materiálové inženýrství
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Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
purchased from local supplier (Centralchem) and used
without further purification.
105
The intercalates were characterized with X-ray powder
diffraction (XRD) by Philips PW 1050 diffractometer
using Cu Kα (0,154 nm) radiation in the region between
2° and 40° (2Θ) at a spead of 2°min-1. The
thermogravimetry/differential thermal analysis was
carried out on Derivatograph MOM Hungary from room
temperature up to 800 °C in an air atmosphere at a
heating rate of 10 °C.min-1.
95
weight lost (%)
100
K_dmso_1
K_dmso_2
K-dmso_3
3%
11 %
90
85
22 %
80
75
70
0
At first the intercalation with DMSO, there were 3
samples prepared, 15.0 g of kaoline natural samples
were mixed in 150.0 ml of DMSO with different
solution concentration: 10%, 50% and 100%
respectively at room temperature under wigorous
stirring for 40 hours. The suspension was centrifuged
(4000 rpm, for 40 min) and washed three times with
etanole to remove excess DMSO. The samples Kdmso-1,
Kdmso-2, Kdmso-3 were dried at 323 K for 12 h and
analyzed by thermogravimetric method and X-ray
analysis. This precursor (Kdmso-3) was then employed for
CuII treated kaoline using the following procedure: 5.0 g
of Kdmso was dispersed in 100.0 ml 0.1 M
Cu(NO3)·2H2O. The mixture was mixed for 30 min. and
then NaOH was added to the dispersion. The mixture
was mixed for 6 hours. After this procedure we obtained
CuII-intercalated kaoline [8]. Excess salts were removed
by washing three times with deionized water followed
by two washings with etanole. The resulting samples
were designated K-CuII.
100
200
300
400
500
Temperature (°C)
600
700
Fig. 1 TG curves of intercalates Kdmso-1, Kdmso-2, Kdmso-3
performed in air atmosphere
Obr. 1 TG krivky intekalovaného kaolínu Kdmso-1, Kdmso-2,
Kdmso-3 namerané pri normálnej atmosfére
The X-ray diffraction (XRD) results on the intercalated
kaolin–dimethyl sulfoxide (Kdmso-3) presented patterns,
together with the corresponding basal spacings obtained
after intercalation, are shown in fig. 2. The 001
reflection of original kaoline appears at 7.20 Å. This
reflection shifts to a higher spacing, 11.30 Å, after
DMSO addition to this clay mineral, confirming the
insertion of this molecule between the clay layers due to
the large dipole moment of DMSO. The weak peak in
8.9° 2Ө corresponds to presence of illite traces [2-4].
K_DMSO_3
KAOLINE
11.27 Å
Intensity (c.p.s.)
7.2 Å
Results and discussion
Thermal analysis of kaoline is in accordance with
literature data [4-10]. Weight reduction is observed in
two steps. The water adsorbed by sample was released
up to 125°C. Drying process leads to reduction of mass
of sample about 0.5 wt. %. The second mass lost is
centered at 560 °C and belongs to endothermal
dehydroxylation of kaoline [10]. Mass of sample was
reduced about 9.24 wt. % during this process.
3
8
13
18
23
28
33
2Ө (degrees)
Fig. 2 X-ray powder diffraction patterns of kaoline and Kdmso-3
Obr. 2 Rtg difrakčné záznamy kaolínu a interkalovaného Kdmso-3
The second step was the treatment of Cu(NO3)·2H2O on
Kdmso-3. This method was reported by Ravindranathan et
al. [8] and it was connected with Na-montmorillonite
using copper acetate. The XRD patterns of CuIIintercalated kaoline, natural kaoline and Kdmso-3 are
given in fig. 3. CuII-intercalated kaoline showed two
new peaks 6.97 Å and 3.53 Å which are attributed to the
compound containing copper CuII , hydroxy and nitrate
ions [12]. After intercalation the color of kaoline
changed from cream to bluish-green. The absence of the
peak at 11.27 Å leads to the suggestion of the complete
removal of the DMSO molecules and their substitution
by new compounds with CuII ions.
Kdmso-1, Kdmso-2, Kdmso-3 thermogravimetric curves are
shown on fig. 1. An intense effect is observed at
~200 °C, attributed to the removal of DMSO. At higher
temperatures, no more effects attributable to DMSO are
observed, finding only the effects characteristic of
kaoline [2]. The amount of DMSO incorporated to
kaoline is about 3%, 11% and 22% of the total mass of
intercalated solid for samples with 10%, 50% and 100%
of DMSO solution. It can be concluded that a higher
solution concentration results an easier intercalation
for kaoline.
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Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Materiálové inženýrství
Material Engineering
7.20 Å
Intensity (c.p.s.)
Acknowledgement
The authors wish to thank the Slovak Grant Agency
VEGA for financial support (Grant VEGA: 1/0530/11
and 1/0185/12).
K_Cu II
Kaoline
K-DMSO_3
11.27 Å
3.53 Å
Literature
6.97 Å
[1] MELO, J., COSTA, T.C., MEDEIROS, A.M., PASKOCIMAS,
C.A. Effects of thermal and chemical treatments on physical
properties of kaolinite, Ceramics International, 36, 2010, p. 33–38
3
8
13
18
23
[2] LOPES, P.C., DAMASCENO da Silva, L.R., Decomposition
kinetics by thermogravimetry for the intercalation of kaolin with
dimethylsulphoxide, Materials Letters, 57, 2003, p. 3397–3401
28
2Ө (degrees)
Fig. 3 X-ray patterns of K-CuII, Kdmso-3 and natural kaoline
Obr. 3 Rtg difrakčné záznamy K-CuII, Kdmso-3 a prírodného kaolínu
[3] AVILA, R.A., FARIA, E.H., CIUFFI, K.J., NASSAR, E.J., New
synthesis strategies for effective functionalization of kaoline and
saponite with lily lating agents, Journal of Colloid and Interface
science, 341, 2010, p. 186–193
K-CuII thermogravimetric curve is shown in the fig. 4.
An intense endothermic effect (mass lost ~ 15 wt. %) is
observed at ~271 °C, attributed to the decomposition of
copper salts. This value corresponds with literature
data [11].
[4] PTÁČEK, P., KUBÁTOVÁ, D., HAVLICA, J., BRANŠTETR,
J., ŠOUKAL, F., OPRAVIL, T. Isothermal kinetic analysis of
the thermal decomposition of kaolinite. Thermochimica Acta
501, 2010, p. 24–29
[5] HONGFEI, CH., QINFU, L., JING, Y., XIAOMAN, D., RAY, L.F.
Influencing factors on kaolinite potassium acetate intercalation
complexes, Applied Clay Science 50, 2010, p. 476–480
100
K-Cu
II
[6] GUERRA, D.L., AIROLDI, C., KALINE, S. Adsorption and
thermodynamic studies of Cu(II) and Zn(II) on
organofunctionalized-kaolinite, Applied Surface Science 254,
2008, p. 5157–5163
Heat flow (µV)
weight lost (%)
95
90
85
80
[7] SIDEHESWARAN, P., BHAT, A.N., GANGULI, P.
Intercalation of salts of fatty acids into kaolinite, Clays and Clay
Minerals 38, 1990, p. 29–32
TG
DTA
271°C
[8] RAVINDRANATHAN, P., MALLA, P.B., KOMARNENI, S.,
ROY, S. Preparation of metal supported montmorillonite
catalyst: a new approach, Catalysis Letters 6 (1990) p. 401–408
75
0
200
400
Temperature (°C)
600
800
Fig. 4 DTA/TG curves of K-CuII performed in air atmosphere
Obr. 4 DTA/TG krivky interkalátu K-CuII namerané
pri normálnej atmosfére
[9] BHATTACHARYYA, K.G., GUPTA, S.S., Calcined
tetrabutylammonium kaolinite and montmorillonite and
adsorption of Fe(II), Co(II), Ni(II) from solution, Applied Clay
Science 46, 2009, p. 216–221
Conclusions
[10] BHATTACHARYYA, K.G., GUPTA, S.S., Adsorption of a few
heavy metals on natural and modified kaolinite and
montmorillonite: A review, Adv. in Coll. and Int. Sc. 140, 2008,
p. 114–131
Organophillic dimethyl sulfoxide DMSO was used for
the modification of kaoline, and may be used as an
entraining agent for the intercalation of other
compounds, such as metal ions CuII. XRD analysis
demonstrated the formation of DMSO-kaoline due to
increasing its basal spacing from 7.20 Å to 11.27 Å. The
second step was adjustment of Cu(NO3)·2H2O.
Intercalated K-CuII showed two new peaks 6.97 Å and
3.53 Å which are attributed to the new compound
containing CuII ions. This conclusion is confirmed also
by thermal analysis. An intense endothermic effect
observed at ~271 °C is attributed to the decomposition
of copper (II) compound.
[11] BISWICK, T., JONES, W., PACULA, A., SERVICKA, E.
Synthesis, characterisation and anion exchange properties of
copper, magnesium, zinc and nickel hydroxy nitrates, Journal of
Solid State Chemistry 179, 2006, p. 49–55
Review: prof. Ing. Darina Ondrušová, PhD.
prof. Ing. Tatiana Liptáková, PhD.
51
Materiálové inženýrství
Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Fibrous Materials Based on Polypropylene and Other Fibers
Vláknité materiály na báze polypropylénových a iných vlákien
doc. RNDr. Mariana Pajtášová, PhD., Ing. Katarína Holcová, prof. Ing. Martin Jambrich, DrSc., Ing. Zuzana
Jankurová, Faculty of Industrial Technologies, University of Alexander Dubček in Trenčín, I. Krasku 1809/34,
020 01 Púchov, Slovakia
The paper deals with the preparation and thermal properties of fibrous materials based on fibers, especially
polypropylene, polyester and polyamide fibers. The fibers were processed in a different way into the filaments (fiber
of an indefinite or extreme length). Fibers with altered transverse and longitudinal geometry provide a wide range
of applications in textiles, especially in terms of performance, particularly transport of heat and moisture. Chemical
structure of textile fibers influences the technical textiles and their application in various industrial fields including
the textile industry, transport, rubber products, construction, agriculture, engineering, food industry and others.
DSC analysis was used to study the course of degradation as well as synthesis processes of materials at elevated
temperatures up to 2000 °C. The DSC curves allowed us to make conclusions for phase transformations, for
desorption, chemical stability and kinetics of reactions. FTIR is an appropriate testing method for determining the
chemical structure, the substance study and identification of organic compounds.
Práca sa zaoberá prípravou a štúdiom vlastností vláknitých materiálov na báze chemických vlákien, a to
polypropylénových, polyesterových a polyamidových. Vlákna boli pripravené vo forme nekonečného vlákna. Meral
sa index kryštalinity metódou infračervenej absorpčnej spektrometrie (FTIR) a kryštalický podiel metódou
diferenčnej skenovacej kalorimetrie (DSC). Meranie základných termických vlastností vzoriek vlákien bolo robené
metódou DSC s využitím meracieho zariadenia DSC- 4 f. Perkin Elmer. Teploty tavenia a kryštalizácie zodpovedajú
endotermickým a exotermickým vrcholom príslušných píkov. Prevažná časť vláknotvorných polymérov a chemických
vlákien má charakter polymorfného polymérneho systému. To znamená, že vzájomné usporiadanie reťazcov resp.
segmentov netvorí jednofázový systém, ale môže prechádzať od čisto amorfných stavov cez rôzne stupne plošného
(mezomorfného) a priestorového (kryštalického) usporiadania. Na základe nameraných výsledkov, sa zistilo, že
index kryštalinity zistený metódou FTIR zodpovedá nameraným hodnotám zistených metódou DSC až na vzorku
PP(1) kde je index kryštalinity menší ako kryštalický podiel.
One of the oldest manufacturing branches of industry
deals with textiles which are closely connected with the
human development as well as the textile industry is one
of the basic requirements of social needs. Nowadays,
development of the textiles relates not only to clothing
applications (garment), but also includes production of
various fabrics applied for industrial products which can
be seen in household and technical spheres [1].
Experiment
List and basic characteristics of the used sample fibres
in relation to investigation:
Polypropylene fiber - 56/43x2 - hollow - PP (1)
Polypropylene fiber - 50/50x2 - micro-ring - PP (2)
Polypropylene fiber - 84/33x1 - Circle - PP (3)
Polypropylene fiber - 56/43x2 - cross - PP (4)
Polyester fiber - 150/48x1 - PES (1)
Polyester fiber - 150/144x1 - PES (2)
Polyester fiber - 100/36x1 - PES (3)
Polyamide fiber - 100/24x1 - PA (2)
Polyamide fiber - 70/24x2 - PA (3)
Polyamide fiber - 72/17x1 - PA (4)
The tested sample fibers were prepared in Chemosvit
Fibrochem Svit, Inc. and the thermal evaluations were
carried out in cooperation with Scientific Institute of
Chemical Fibres Svit.
Broader understanding of social and work activity,
increasing demands on product quality are subjected to
the source of raw materials - fibers. This function of
the broadest understanding is fulfilled by natural
fibers, metallurgical and chemical fibers, fibers of
polymers [2, 3].
The development and growth of new fibrous materials
based on renewable raw materials as well as the
development of biodegradable fibrous materials from
biopolymers of microbial types are considered to be
materials of the future. The development of the multicomponent and hybrid materials (integrated fabric)
seems to be very important because of their good
physiological properties, uniform stability, high
chemical, thermal and audio resistance for application in
technical textiles [4].
Determination of the proportion of crystalline by
DSC method
Measurement of fundamental thermal properties of
samples of fibers was done using DSC method on
measuring device DSC-4 comp. Perkin Elmer [5 – 7].
The measurement procedure includes these steps:
52
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Materiálové inženýrství
Material Engineering
The first one step is connected with the heating
procedure. The fine short fibers (initial sample fibers)
were compressed in standard aluminum pans and heated
from an initial temperature of 60 °C to the final
temperature of 260 °C while constant rate for heating
was 10 °C/min, but the pan could be even heated up to
290 °C.
Structural evaluation of fiber properties by FTIR
method
Infrared
absorption
spectroscopy
method
is
electromagnetic radiation absorption of molecules. The
most of the fiber-forming polymers and fibers can be
understood as polymorphic and polymer system and it
means that mutual arrangement of the chains or
segments does not form one-phase system but it can
transfer to pure amorphous states through the different
stages of mesomorphic and crystalline arrangement.
The second step represents the cooling sample where
the molten sample fibers were held at 260 °C or 290 °C
for 6 minutes and after that these sample fibers were
cooled while temperature was decreased by 10 °C per
minute until the temperature gained 60 °C.
To determine the crystallinity of fibers by means of
infrared absorption spectroscopy is used KBr pellet
technology [6].
The last one step is closely connected with DSC record
and evaluation of obtained results. DSC record –
thermogram was obtained by the evaluation of
measured data where the course of cooling is
represented by a crystallization exotherm of original
sample and this exotherm is characterized by the
temperature of crystallization Tc, approx. crystallization
enthalpy ΔHc of the given sample.
Individual fibers were finely cut and pressed by help of
KBr technology into tablets and FTIR spectrometer IFS
88 was used for measurement of FTIR spectra. All the
obtained values of measurement are shown in the
following tables 2-4.
Tab. 2 Index of crystallinity of polypropylene fibers
Tab. 2 Index kryštalinity polypropylénových vlákien
The values of enthalpy and crystallization of the
samples were obtained from areas endotherm or
exotherm in relation to the selected temperature ranges the limiting values of integration. Melting and
crystallization correspond to endothermic and
exothermic peak of the appropriate peaks.
Sample
PP (1)
PP (2)
PP (3)
PP (4)
To calculate the proportion of crystalline, the given
equation was used [6]:
Kp 
H 
 100
H
IK
1.18
1.47
1.42
1.51
Index of crystallinity of polypropylene fibers was
calculated according
(1)
IK = A997 / A2723
(2)
where A997 is an absolute absorbance of the absorption
band at wavenumber of sample PP 997 cm-1 influencing
crystallinity and A2723 is absolute absorbance of the
absorption band at wavenumber of sample PP 2723 cm-1.
The given bands are neutral as well as they represent an
internal standard.
where Kp - crystalline portion [%], H  - enthalpy for
melting of the sample, H - enthalpy for melting of
total crystalline polymer fibers, H = 198,11 [J/g].
Measured values of crystalline portion are shown in the
tab. 1.
Tab. 3 Index of crystallinity of polyester fibers
Tab. 3 Index kryštalinity polyesterových vlákien
Tab. 1 Crystalline portion of fibers
Tab. 1 Podiel kryštalinity vlákien
Sample
PP (1)
PP (2)
PP (3)
PP (4)
PES (1)
PES (2)
PES (3)
PA (2)
PA (3)
PA (4)
Crystalline portion
[%]
37.3
43.9
44.3
40.7
35.6
33.2
33.8
32.9
36.6
34.3
Sample
A971 / A792
A1342/ A1371
PES(1)
1.12
1.18
PES (2)
1.61
1.56
PES (3)
1.24
1.25
The ratio of A971/A792 is the ratio of absorbencies which
are proportional to amount of trans-conformations and
ratio of A14342/A1371 is trans index.
Tab. 4 Index of crystallinity of polyamide fiber
Tab. 4 ndex kryštalinity polyamidových vlákien
53
Sample
PA (2) (PA 6)
A927 / A1118
0.56
A960 / A975
0.91
PA (3) (PA 6)
0.68
1.01
PA (4) (PA 6)
0.69
1.09
Materiálové inženýrství
Material Engineering
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
The ratio of A927/A1118 is the ratio of the absolute
absorbance at wave numbers 927 cm-1 (affects the
crystallinity) and it is proportional to the amount of
crystalline structural modifications at 1118 cm-1
(internal standard). The A960/A975 is proportional
to α form.
Acknowledgement
The authors are grateful to the Slovak Grant Agency
VEGA 1/0530/11 for financial support.
Literature
[1] JAMBRICH, M., SROKOVÁ, I., STARIGAZDA, J., ŠIARNIK,
M. The structure and properties of fibre materials on basis of
synthetic and polylactide polymers. In 2nd International material
conference TEXTO 2006, 17th–18th August 2006, Ružomberok
Slovak republic, p. 7-12
0,9
Abs
0,75
[2] SÝKOROVÁ, J. Štruktúra a vlastnosti bytových textílií
z chemických vlákien, dizertačná práca, FPT TnU AD, Púchov
2006. 123 s.
0,6
[3] JAMBRICH, M., et al. História rozvoja výroby chemických
vlákien na Slovenskú a v Čechách, KP CHTF STU, Bratislava
1996
0,45
0,3
[4] JAMBRICH, M., BUDZÁK, D., KOCHAN, J. „Aspekty rozvoja
vláknitých materiálov vo svete a u nás.“ In CHemZi 3/1,. 2007,
256 s.
0,15
0
4000
3500
PP2A
[5]
3000
2500
2000
1750
1500
1250
1000
750
500
1/cm
Fig. 1 FTIR spectrum of polypropylene fiber
Obr. 1 FTIR spectrum polypropylenového vlákna
STN EN ISO 11 357-1, Plasty snímacia kalorimetria (DSC),
časť 1:Všeobecné princípy.1997.
[6] JAMBRICH, M., PIKLER, A., DIAČIK, I. Fyzika vlákien, Alfa
Bratislava, 1987, 539 s.
[7] STN EN ISO 3146 Plasty, Hodnotenie procesu tavenia (teplota
tavenia alebo rozsah teplôt tavenia) semikryštalických
polymérov kapilárnou rúrkou a polarizačným mikroskopom.
2000
Conclusions
According to the measurement results which are
presented in the experimental part, it was found that the
index of crystallinity index measured by the FTIR
method corresponds to the measured values which were
obtained by DSC PP(1) where the crystallinity index is
lower than crystalline portion. It can be caused on the
basis of 5% error which occurred during measurement
by DSC method.
Review: prof. Ing. Darina Ondrušová, PhD.
prof. Ing. Tatiana Liptáková, PhD.
_____________________________________________________________________________________________
Kovárna v Betlehem rozšířuje výrobu
Největší americká volná kovárna Lehigh Heavy Forge Corporation (LHF), která několikrát změnila název,
dříve byla známa jako Betlehem Steel Corp., a dnes je se svými lisy 100 MN a 20 MN nejvýznamnější
volnou kovárnou na západní polokouli, připravuje výrazné zvýšení výroby. V prvém kroku počítá se
zvýšením výroby kovářských ingotů o 40 % a ve druhém kroku o 100 %. Nadále počítá s dodávkami
výkovků pro energetiku, stavbu lodí, zbrojní průmysl a další oblasti. Například dodává válce o hmotnosti
přes 150 t pro válcovny tlustých plechů. Zvýšení výroby ingotů by mělo vést ke zkrácení dodacích
termínů [1].
Kovárna již zahájila výrobu výkovků pro firmu Babcock & Wilcox Co, která z nich bude vyrábět malý
modulární reaktor (SMR) B&W mPower. Jde o lehkovodní reaktor, jehož výkon bude možné volit ve
stupních po 180 MWe. Bližší údaje zatím nebyly zveřejněny. Objednané výkovky však naplní kapacitu
kovárny na jeden rok. Bude využívat lis 100 MN a zpracovávat ingoty o průměru až 3300 mm z vlastní
ocelárny [2]. Tento typ jaderné elektrárny nabízí Americká firma Westingouse i pro dostavbu jaderné
elektrárny Temelín v ČR.
Literatura
[1] http://www.forgemag.com/Articles/Feature_Article/BNP_GUID_9-5-2006_A_10000000000001153561
[2] http://forgingmagazine.com/forming/lehigh-heavy-forge-supply-bw-reactor-forgings?page=1
54
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Materiálové inženýrství
Material Engineering
Investigation of Thermostable Esters from O-(carboxymethylstarch)
Štúdium termostabilných esterov z O-(karboxymetylškrobu)
RNDr. Viera Mazíková, PhD., doc. Ing. Milan Olšovský, PhD., Faculty of Industrial Technologies in Púchov,
University of Alexander Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia
The fatty acid esters of O-(carboxymethyl) starch (CMS) were prepared by esterification with fatty acid (C18)
chlorides under various reaction conditions. When the molar ratio CMS: RCOCl was 1:3 and higher, they were
obtained of CMS esters with DSE > 2 and were soluble in organics solvents (DMSO, chloroform). The structural
properties of the prepared polysaccharides were characterized by Fourier-transform infrared (FT-IR) spectroscopy.
Degree of esterification (DSE ) was estimated from FT-IR spectroscopy. Thermal stability of the prepared esters was
studied by TGA and DSC methods. The esters of CMS with higher DSE may be used at preparation of plastic
materials or blends with synthetic polymers.
StearátyO-(karboxymetylškrobu)(StCMS) sa pripravili klasickou esterifikáciou so stearoylchloridom za rôznych
podmienok reakcie zmenou mólového pomeru, teploty a času reakcie s cieľom propraviť vyššiesubstituované deriváty
(najvyššie dosiahnuteľné DS =3). Od mólového pomeru CMS : StCOCl = 1 : 3 a vyššom boli vo vode nerozpustné,
ale bola sledovaná ich rozpustnosť v rôznych organických rozpúšťadlách. Následne sa charakterizovali infračervenou
spekroskopiou s Fouriérovou transformáciou (FT-IR), ktorá potvrdiai prítomnosť esterovej skupiny a umožnila
výpočet DS podľa ubúdajúcej plochy pásov prislúchajúcich hydroxylovým skupinámpri vlnočte ~3500 cm-1 v mm2.
Vo FT-IR spektrách pripravených StCOCl sa sledoval najmä pás pri vlnočte ~1740 cm-1, prislúchajúci vibráciám
esterových skupín, ktorý sa s pribúdajúcim DS zvyšoval a ubúdajúci pás hydroxylových skupín na výpočet DS.. U
vybraných derivátov sa študovali termické vlastnosti pomocou termickej analýzy (TGA) a diferenčnej kompenzačnej
kalorimetrie (DSC). Relatívne najviac esterifikovany derivát StCOCl-IV s DS = 2,46 mal zvýšenú termickú stabilitu v
porovnaní s východiskovým CMS. Optimálnymi reakčnými podmienkami možno vyhodnotiť teplotu 70 °C, reakčný
čas 3 až 5 h a mólový pomer 1 : 5. Vyššiesubstituované deriváty vzhľadom k svojim termickým vlastnostiam môžu
byť použité pri príprave rôznych polymérnych zmesí.
Chemically modified starches in the past few decades
have played a major role in the food, pharmaceutical
industry [1] and in other industrial applications such as
medicine [2], cosmetic fields [3], plastic materials and/or
blends with synthetic polymers [4] because they are,
analogous to starch, low cost and biodegradable [5].
They possess some unique properties, not found in
natural starches, for example solublity in unheated water,
changes in reological properties, lower gelanization
temperature, less retrogradation, pH stability [5], etc.
Water-soluble carboxymethyl starch (CMS) with DS
~ 0.25 – 0.3 is industrially produced in large quantities
and has been rarely studied. It can be used as drilling
fluids [6], components of cross-linking formulation in
easy-care finishing of textile fabrics [7], hydrogels after
crosslinking by radiation [8], etc. Chemical modification
(etherification, esterification) of CMS leads to
preparation of water-soluble amphiphilic polymers with
low degree of substitution and with adaptive and tensionactive properties, which might find applications as
emulsifiers, surface active agents [9], etc. Continuing in
the project concerning the chemical modification of
polysaccharides, we gives report on esterification of
CMS with fatty stearoyl halides in this paper. The CMS
–fatty acid ester with DS = 0.6 – 2.5 were obtained and
their thermal properties were evaluated.
Experiment
Materials: The O-(carboxymethyl)starch (CMS) with
DS = 0.3 used in study was gift from Prof. Th. Heinze,
Friedrich- Schiller University (Jena, Germany).
N,N-dimethylformamide
(DMF),
Pyridine,
4Dimethylaminopyridine (4-DMAP), Stearoyl chloride
(StCOCl), dimethylsulfoxide (DMSO), chloroform were
commercial product from Sigma-Aldrich Chemical Co.
(Steinheim, Germany).
Methods: Fourier-transform infrared (FT-IR) spectra
were obtained on the Nicolet 6700 spectrometer with an
ATR extension piece (Smart orbit diamond) with using
128 scans at a resolution of 4 cm-1 at the Institute of
Chemistry, SAS (Bratislava, Slovak Republic). The
spectra were normalized using the band at 1165 cm-1 for
CMS. The band area of the ν (OH) vibrations was
calculated from the region 3865-3005 cm-1 and that of
the ν(CO) vibrations from the region 1770-1720 cm-1.
Thermogravimetric analysis (TGA) was used to
evaluate the thermal stability. The measurements were
performed on the thermobalance Mettler Toledo
TGA/SDTA 851e in temperature range 25°C - 550°C in
nitrogen atmosphere with a heating rate 10°C/min.
Triplicates of about 2 mg of sample were run in each
55
Materiálové inženýrství
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Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
experiment and the presented data consist of average
values of the temperature at which there is 20 % weight
loss and standard deviations. The thermal behaviour
some of the CMS – esters was evaluated using
differential scanning calorimeter Mettler Toledo DSC
821e with heating and cooling rates 10°C/min in the
temperature range from –30 °C to 500 °C in nitrogen
atmosphere. Before analysis, the CMS samples were
dried at 45 °C in vacuum.
Solubility: The solubility of the esterified CMS samples
in chloroform, dimethylsulfoxide and deionised water
was estimated. 10 mg of sample was mixed with 10 mL
of solvent under magnetic stirring for 5 h. Chloroform,
DMSO and water was kept at ambient temperature.
Esterification: 1.0 g of CMS was introduced into 30 cm3
of DMF and the mixture was stirred at room
temperature for 2 h. Subsequently the fatty acid chloride
StCOCl in various molar ratios was added and the
mixture with or without addition of catalysts (DMAP)
was stirred at different reaction conditions (tab. 1). The
reaction product was precipitated into ethanol, filtered
and then purified by Soxhlet extraction with ethanol for
8 h yielding samples StCMS -III-V.
FTIR analyses of the derivatives were transformed into
COO- form using the potentiometric titration at
controlling pH – value.
Results and discussion
In to order to study the effect of hydrophobization of the
CMS on the structure and properties on a series of
StCMS derivatives with different degrees of
esterification, the reaction of the CMS dissolved in
DMF with stearoyl chlorid in presence of pyridine, and
with or without DMAP as catalyst was used. Prepared
stearoyl esters under various reaction conditions were
insoluble in water and characterized by FT-IR
spectroscopy. Results are given in tab. 1. The yields of
the StCMS derivatives showed large variations, very
probably, due to losses by degradation at high
temperatures and long reaction times of the esterified
polysaccharide, which is non-precipitable by ethanol.
The solubility of CMS esters were estimated in various
solvents with different polarity (in chloroform, DMSO,
water) (tab. 1). The DSE has strong affect on the
solubility of the CMS derivatives in solvents, shifting
from the non-esterified CMS and the esters with DSE up
to 0.13 that are soluble in water, to the fully esterified
CMS that is partially soluble in nonpolar solvents such
as chloroform. The samples with higher DSE (1.4) are
partially dissolved in the polar aprotic solvent DMSO.
However, the presence of the anionic carboxymethyl
substituent affects the solubility of CMS and its
derivatives. In aqueous media up to DSE = 1.4 they are
soluble only in the salt (Na+) form. In aprotic and
organic solvents, the modified polymers need the
protonated form so that they are solublized.
Tab. 1 Reaction conditions and yield for preparation of the esters of CMS and their solubility
Tab. 1 Reakčné podmienky a výťažky pripravených esterov CMS a ich rozpustnosť vo vode a organických rozpúšťadlách
Sample
StCMS-III
StCMS-IV
StCMS-V
Mole ratio
CMS:St COCl
Time
(h)
Temperature
(°C)
Yield
(g/g)c
1 : 3 a,*
1:5a
1 : 4 b,*
3
70
3
70
6
100
Soluble in
H2O DMSO CHCl3
DSE from
FTIRd
0.90
CO- bands
(ν-1)
1747
0.65
is
sw
is
0.98
1739
2.46
is
t
sw
0.86
1739
1.66
is
is
sw
a) DMF/py + DMAP; b) DMF/py; s, soluble; sw, swellable; g, gel; t - turbid solution; is- insoluble* - Na+ for c Expressed as g of the recovered
derivative per g HEC (on dry mass basis);d Calculated from the (OH) band area diminution in relation to DSmax=3 (DSCM=0.3).
%
FT-IR spectroscopy of the StCMS (tab. 1) confirmed
the esterification of CMS. The absorbtion band at 35003400 cm-1 (νOH) of the starting CMS decreases due to
the substitution of the OH groups by the ester which
showed characteristic bands at 2926-2852 cm-1 (νCH2)
and 1747 cm-1 (νCO esters).
100
80
60
III, DSE=0.65
CMS
40
The DSE-values were calculated from the relation
between diminish of (OH) absorption band area with
increasing esterification degree.
IV, DSE=2.46
V, DSÉ=1.37
20
50
0
min
100
5
150
10
200
15
250
20
300
25
350
30
400
35
450
40
500
C
o
45
Fig. 1 TGA thermograms of StCMS derivatives and unmodified CMS
Obr. 1 TGA krivky stearátov CMS a CMS
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Materiálové inženýrství
Material Engineering
The results are as follows:
^exo
- DS increased with increasing of the mole ratio; almost
completely substituted derivatives (VIII) were
prepared with the mole ratio of CMS : StCOCl =
1 : 5;
CMS
III, DSE=0.65
Wg^-12
- the optimum reaction temperature was 70 °C and the
optimum reaction time ranged between 3 and 5 h;
IV, DSE=2.46
- the selected derivatives with higher DS showed
excellent thermal stability with the onset of
decomposition in the range from 260 °C to 397 °C.
V, DSÉ=1.37
0
0
50
5
100
10
150
15
200
20
250
25
IV
300
30
350
35
40
400
45
450 °C
min
Fig. 2 DSC curves some of the CMS-esters(III-V) and started CMS
Obr. 2 DSC krivky stearátov CMS a CMS
The thermal stability of the CMS, investigated using
TGA, was measured as the total weight loss of the
sample as the temperature was increased (fig. 1 and
tab. 2). The CMS and CMS esters with low DS showed
two stage weight loss, the first one minor corresponding
to the loss of water around 100 °C and the second
corresponding to its decomposition. Water is the main
product of decomposition at temperatures below 300 °C
(i.e. water formed by inter and intra-molecular
condensation of the starch hydroxyls). CMS underwent
total weight loss at 321.9 °C while, in the case of CMS
esters (III-V with DSE from 0.65 up to 2.46) the
temperature increased from 335.3 °C to 397.3 °C
(tab. 2).
Tab. 2 TGA and DSC results analyses of the CMS-esters and CMS
Tab. 2 Výsledky termickej analýzy StCMS v porovnaní s CMS
StCMS-III
Ton1
(°C)
262.5
Ton2
(°C)
335.3
Tm
(°C)
87.6
Weight loss at
550 °C (%)
88
StCMS-V
319.6
397.3
41.6
85
CMS
259.7
321.9
99.8
88
Sample
Ton1 = onset of decomposition, Ton2 = onset of end decomposition.
The DSC curves of the measured CMS esters are
characterized by multipeak (fig. 2). CMS showed
gelanization endotherm about 76 °C according to the
literature. The first peak near temperature of 100 °C
corresponding to evaporation of free water which is also
seen in fig. 2. In the case of the high substituted
derivative IV and V the endotherms between 40 – 50 °C
correspond to melting of structure, formed by ordering
of the fatty acid substituents. This indicated the L - C
properties of the derivatives.
It is possible to use higher substituted esters of CMS as
additives to different synthetic polymers with the aim to
improve the thermal stability, mechanical properties and
biodegradability of the composites.
Acknowledgement
This work has been supported by the Slovak grant
agency APVV, project No. SK-PL-0044/09.
Literature
[1] KITTIPONGPATANA,
O.S.,
SIRITHUNYALUG,
J.,
LANGER, R. Preparation and physicochemical properties of
sodium carboxymethyl mungbean starches. Carbohydrate
Polymers 63, 2006, p. 105–112
[2] THEVIS, M., OPFERMAN, G., SCHÄNZER, W. Detection of
the plasma volume expander hydroxyethyl starch in human
urine. Journal of Chromatography B 744, 2000, p. 345–350
[3] CHOI, S.G., KERR, W.L. Water mobility and textural properties
of native and hydroxypropylated wheat starch gels.
Carbohydrate Polymers 51, 2003, p. 1–8
[4] SWANSON, C.L., SHOGREN, R.L., FANTA, G.F., IMAN, S.H.
Starch-plastic materials preparation, physical properties, and
biodegradability (a review of recent USDA research). J. Environ.
Polym. Degrad. 1, 1993, p. 155–166
[5] ABURTO, J., ALRIC, I., THIEBAUD, S., BORREDON, E.,
BIAKIARIS, D., PRINOS, J., PANAYIOTOU, C.J. Synthesis,
characterization and biodegradability of fatty-acid esters of
amylose and starch. J. Appl. Polym. Sci. 74, 1999, p. 1440–1451
[6] WU, D.H., ZHANG, J.W. Preparation of carboxymethyl starch
for drilling muds. Oilfield Chem. 10, 1993, p. 209–213
[7] MOSTAFA, K.H.M., MORSY, M.S. Utilization of newly
tailored modified starch products in easy-care finishing.
Carbohydr. Polym. 55, 2004, p. 323–331
[8] YOSHII, F., ZHAO, L. WACH, N., NAGASAWA, H.,
MITOMO, KUME, T. Hydrogels of polysaccharide derivatives
crosslinked with irradiation at paste-like condition. Nucl. Instr.
and Meth. Phys. Res. B, 208, 2003, p. 320–324
[9] SROKOVÁ, I., EBRINGEROVÁ, A., HEINZE T.H.
Emulsifying agents based on O-(carboxymethyl) starch. Tenside
Surf. Det. 38, 2001, p. 277–281
Conclusions
Review: prof. Ing. Darina Ondrušová, PhD.
doc. Ing. Mariana Pajtášová, PhD.
Higher substituted derivatives of CMS were prepared by
the classical reaction with higher fatty acids chlorides
using DMF/Py as reaction medium without and with
DMAP as a catalyst.
57
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Material Engineering
Hutnické listy č.7/2012, roč. LXV
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Methods of Ageing and Characterization of LDPE/CMS Blends
Metódy starnutia a charakterizácia LDPE/CMS zmesí
Ing. Petra Skalková, PhD., Ing. Jana Pagáčová, PhD., Faculty of Industrial Technologies, University of
Alexander Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia, Ing. Martin Březina, CSc., Ing. Michal
Kapusňák, VUJE a.s. Okružná 5, 918 64 Trnava, Slovakia
Synthetic plastics, such as polystyrene, polypropylene and polyethylene, are used widely in daily life, in food
industry, biomedical field and agriculture. A heavy environmental pollution accompanies their uses, because
they need hundreds of years to degrade, and the disposal of waste plastics has become a serious problem.
Therefore, in the past two decades, the attention have been paid to biodegradable materials as alternatives to the
petroleum-derived plastics. Natural biopolymers including starch, cellulose and chitosan were tested, independently
or in combination with synthetic polymers, for the possibility to form a fully or partially biodegradable film. From
these materials, starch is the most attractive candidate because of its low cost, easy availability and high production
from annually renewable resources.
Syntetické a polosyntetické polymérne materiály boli pôvodne vyvinuté pre ich trvanlivosť a odolnosť voči všetkým
formám degradácie, vrátane biodegradácie. Obľubu si získali okrem iného aj pre ich ľahkú spracovateľnosť
a možnosť výroby veľmi rozmanitých a cenovo výhodných výrobkov. To, čo robí polymérne materiály výhodnými
a užitočnými, prispieva na druhej strane k tvorbe vážnych problémov vo vzťahu k životnému prostrediu. Hromadenie
odpadov z plastov a s tým súvisiace problémy vedú k stále dôslednejšiemu uvedomovaniu si skutočnosti, že
používanie plastov s dlhodobou životnosťou pre krátkodobé použitie nie je v súlade s celkovým úsilím ľudstva
o ochranu životného prostredia. V poslednom období sa vyvíja tlak na znižovanie produkcie obalových materiálov.
Dôvodom sú aj problémy spojené s recykláciou a výrobou, na ktorú sú potrebné suroviny z neobnoviteľných zdrojov.
Aby sa zabránilo ich hromadeniu na skládkach odpadu a znečisťovaniu životného prostredia, vyvíjajú sa materiály,
ktoré sú biodegradovateľné. Práca sa zaoberá charakterizáciou zmesí nízkohustotného polyetylénu (LDPE)
s rôznym obsahom karboxymetylškrobu (CMS) metódami REM a AFM. Na vybraných LDPE/CMS zmesiach sa
uskutočnil NaOH test.
of surface growth [6, 7]. The surface growth may not
result in the degradation of the body of the polymer if
the starch is confined to the surface. Characterization of
unhydrolyzed and hydrolyzed composite was performed using tapping mode atomic force microscopy to
ascertain the pore size, surface roughness of the film.
A majority of widely used polymeric materials developed
in the past 50 years is characteristically durable [1]. For
many applications such as packaging and fil-tration, the
long-lasting properties of polymeric material are not
desired; instead a short-term performance from the
polymer is required. Degradable composites are
considered as alternatives to the conventional plastics.
During the last three decades, native starch and its
derivatives have been incorporated into synthetic plastics
in formulating degradable composites [2–5]. Starch is
cheap, annually the cropis harvested, and the use of
starch contributes to saving of the scarce petroleum
resources. In addition, starch has adequate thermal
stability for melt blending with synthetic plastics to
produce unique degradable plastics. Although the
incorporation of starch as an additive in synthetic plastic
is highly attractive, the overall degradability of the final
composite has been called into question.
Experiment
Materials
Blends consist of the low density polyethylene (LDPE)
from Slovnaft Petrochemicals, appropriate for packing
application and O-(carboxymethyl) starch (CMS) with
degree of substitution DS = 0.3 was prepared by
reaction of potato starch (Jena) suspended in methanol
with monochloracetic acid after the activation with
40 % aqueous sodium hydroxide. Ethylene/acrylic acid
copolymer containing 15 wt. % of acrylic acid was
supplied from Aldrich [8].
One way to enhance the degradability of the overall
composite is to increase the degradable starch
component in the composite. The enhancement in
degradability of the composite by starch addition is
often obtained at the expense of other mechanical
properties. When the starch compatibilized synthetic
polymer composite is placed in a biologically active
environment, the microbes show considerable amount
Method of ageing - NaOH test
The samples were treated with 10% aqueous NAOH
solution during 5 days at room temperature [9]. Then,
they were washed with water and acetone, dried to
constant mass and weighed. The actual content of CMS
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Materiálové inženýrství
Material Engineering
in blend after NaOH test was calculated from the
expression:
X  X
(1)
X 0
1  X
between CMS and moisture than compatibilized blends;
as a result, they can absorb more moisture.
where X - weight fraction of CMS in blend after the test;
X0 - weight fraction of CMS in blend before the test;
X - relative weight loss during the test.
AFM measurements
Contact mode AFM was used to characterize LDPE/CMS
blends before and after NaOH test. All AFM images were
recorded with an atomic force microscope NT-206 (Co.
Micro test Machines Belarus) operated under ambient
conditions. The cantilever of MikroMasch NSC36/AIBS
with spring force constant of 0.95 N/m was used. The
surface morphology was evaluated on the base of 2D
AFM images and surface roughness as statistical
characteristics [10]. Images were evaluated by
SurfaceXplorer 1.0.8.65 program.
Fig. 2 SEM photograph of LDPE/20 wt. % CMS blend without of
compatibilizer EAA
Obr. 2 REM snímka zmesi LDPE/20 hm. % CMS bez
kompatibilizátora EAA
Whereas, the EAA in the compatibilized blends can
react to form hydrogen bonds with the hydroxyl groups
of carboxymethyl starch, or to form a physical
interaction between ethylene segments in EAA and in
LDPE. Hence, the amount of hydroxyl groups in CMS
for absorption or forming of hydrogen bonds with
moisture was reduced.
SEM
Before documentation all specimens were broken at the
temperature of liquid nitrogen and fracture surfaces
were coated by ultrathin layer of gold using highvacuum evaporation. Micrographs of specimens were
taken by the scanning electron microscope (Tescan
VEGA TS 5130 MM) at the accelerating voltage of
20 kV. All micrographs are backscattered electrons
(BSE) images.
Results and discussion
Fig. 3
SEM photograph of LDPE/20 wt. % CMS blend with 50 wt.
% of compatibilizer EAA
Obr. 3 REM snímka zmesi LDPE/20 hm. % CMS s 50 hm. %
kompatibilizátora EAA
Tab. 1 Results of NaOH test for LDPE/CMS blends with and
without EAA
Tab. 1 Výsledky NaOH testu zmesí LDPE/CMS s a bez EAA
Fig. 1 Structural unit of carboxymethyl starch
Obr. 1 Štruktúrna jednotka karboxymetylškrobu
The morphological characteristics of LDPE/CMS
blends were determined by SEM. Fig. 2 reveals that the
surface of the carboxymethyl starch granules is very
smooth. In fact, it is quite similar to native potato starch.
Its shape is ranging from oval to irregular with the size
being varied from 6 to 55 µm. However, the average
size is in the range of 24-31µm.
Sample
Weight loss (g)
LDPE/20 wt. % CMS/10 wt. % EAA
0.024±0.015
LDPE/20 wt. % CMS/50 wt. % EAA
0.021±0.021
LDPE/20 wt. % CMS/0 wt. % EAA
0,024±0,007
After chemical degradation of LDPE/CMS blend by
means of NaOH the various values were found (tab. 1).
Increasing value of the weight loss in LDPE/CMS
blends is probably connected with the increasing
amount of CMS amorphous phase.
As seen in fig. 2, there is a gap between the CMS
particle and the LDPE matrix. As opposed to the
compatibilized blend film there is a co-continuous phase
between the two phases as shown in fig. 3. This is
because EAA helps to promote the interfacial adhesion
between the LDPE phase and the CMS phase. In other
words, uncompatibilized blends have more surface area
59
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a)
Hutnické listy č.7/2012, roč. LXV
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the shape of CMS granules ranged from oval to
irregular. Its size varied from 6 - 55 µm in diameter
with an average size of about 24 - 31µm. Presence of
EAA helps to promote the interfacial adhesion between
the LDPE phase and the CMS phase. Chemical
degradation NaOH solution of LDPE/CMS blends (with
or without of EAA) influence the molecular structure of
polymer matrix. The observed changes can be due to the
action of the aquous NaOH solution at the amorphous
part of polyolefin – carboxymethyl starch interphase.
Such a possibility was confirmed by the analysis of the
data from AFM. The changes of the surface of
LDPE/CMS blends caused by chemical degradation
processes can lead to visible changes of the mechanical
behaviour of blends.
b)
Fig. 4 AFM image of LDPE/20 wt. % CMS blend with 0 wt. % of
compatibilizer EAA: a) before and b) after NaOH test
Obr. 4 AFM snímka zmesi LDPE/20 hm. % CMS s 0 hm. %
kompatibilizátora EAA: a) pred a b) po teste s NaOH
Literature
[1] ALBERTSSON, A.C., KARLSSON, S. The three stages in
degradation of polymers-polyethylene as a model substance,
Journal of Applied Polymer Science 35 (5), 1988, p. 1289-1302
[2] GRIFFIN, G.J.L., INTERNATIONAL PATENT APPLICATION
PCT WO88/09354, 1988
a)
[3] KOŠTIAL, P., JANČÍKOVÁ, Z., STÝSKALA, V., KUBLIHA,
M., MADAJ, R., RUŽIAK, I., DEDIČOVÁ, J., HREHUŠ, R.,
JONŠTA, P. The Influence of Carbon Fillers on Thermal
Transport in Polyurethane, Defect and Diffusion Forum 326-328,
2012, p. 69-74
b)
Fig. 5 AFM image of LDPE/20 wt. % CMS blend with 10 wt. % of
compatibilizer EAA: a) before and b) after NaOH test
Obr. 5 AFM snímka zmesi LDPE/20 hm. % CMS s 10 hm. %
kompatibilizátora EAA: a) pred a b) po teste s NaOH
[4] DANJAJI, I.D., NAWANG, R., ISHIAKU, U.S., ISMAIL, H.,
MOHD ISHAK, Z.A. Degradation Studies and Moisture Uptake
of Sago-Starch Filled Linear Low-Density Polyethylene
Composites, Polymer Test 21, 2002, p. 75-81
[5] PEDROSA, A. G., ROSA, D.S. Mechanical, Thermal and
Morphological Characterization of Recycled LDPE/Corn Starch
Blends, Carbohydrate Polymers 59, 2005, p. 1-9
[6] MALI, S., SAKANAKA, L.S., YAMASHITA, F., GROSSMAN,
M.V.E. Water Sorption and Mechanical Properties of Cassava
Starch Films and Their Relation to Plastisizing Effect.
Carbohydrate Polymer 60(3), 2005, 283-289
a)
[7] AVELLA, M., ERRICO, M.E. Preparation and characterisation of
compatibilized polycaprolactone/starch composites, Polymer 41,
2000, p. 3875-3881
b)
Fig. 6 AFM image of LDPE/20 wt. % CMS blend with 50 wt. % of
compatibilizer EAA: a) before and b) after NaOH test
Obr. 6 AFM snímka zmesi LDPE/20 hm. % CMS s 50 hm. %
kompatibilizátora EAA: a) pred a b) po teste s NaOH
[8] SKALKOVÁ, P., JAKUBÍKOVÁ, Z., JOCHEC-MOŠKOVÁ, D.
LDPE/glukuronoxylan blends: Preparation and study of thermal
and mechanical properties, Cellulose Chemistry and Technology
42 (4-6), 2008, p. 189-196
Figs. 5 - 6 represent the 2D surface morphologies of
LDPE/20 wt. % CMS blends with various amount of
compatibilizer EAA before and after chemical
degradation by NaOH. The surface morphology of
blend without compatibilizer after NaOH test is
different (fig. 4). The surface roughness of blend after
test slightly increases from value ~30 nm to ~40 nm.
There are not any significant differences between
roughnesses of blends with compatibilizer EAA. Before
and after NaOH test, the roughness of LDPE/20 wt. %
CMS blend with 10 and 50 wt. % of compatibilizer
EAA is about 30 nm and 20 nm, respectively.
[9] ZUCHOWSKA, D., HLAVATA, D., STELLER, R., ADAMIAK,
W., MEISSNER, W. Physical structure of polyolefín-starch blends
after ageing, Polymer Degradation and Stability 64, 1999, p. 339-346
[10] PAGÁČOVÁ, J., PLŠKO, A., MICHALKOVÁ, K.
Functionalization of glass surface by nanocomposite TiO2 films,
Physics and Chemistry of Glasses: European Journal of Glass
Science and Technology Part B(in press)
Review: prof. Ing. Darina Ondrušová, PhD.
doc. Ing. Mariana Pajtášová, PhD.
Conclusions
Carboxymethyl starch is a material that can be used to
make biodegradable plastics. By SEM, it was found that
60
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Materiálové inženýrství
Material Engineering
Thermal Stability of Glasses of the Li2O - 2SiO2 System
Termická stabilita skiel systému Li2O - 2SiO2
prof. Ing. Eugen Jóna, DrSc., Ing. Simona Lendvayová, Ing. Stanislava Uherková, doc. RNDr. Mariana
Pajtášová, PhD., prof. Ing. Darina Ondrušová, PhD., Department of Material Technologies and Environment,
Faculty of Industrial Technologies, University of Alexander Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov,
Slovakia, Ing. Jozef Kraxner, PhD., Vitrum Laugaricio – Joint Glass Center of Institute of Inorganic Chemistry
SAS, Alexander Dubček University of Trenčín and RONA Lednické Rovne, Študentská 2, 911 50 Trenčín, Slovakia
To evaluate the thermal stability of oxide glasses against crystallization, a criterion based on the length of induction
period of crystallization was used. Two glasses with the composition of Li 2O - 2SiO2 (a) and Li2O - 2SiO2 - 0.1NiO
(b) were prepared and validity of this criterion was tested by applying it to there glasses. It was found that the
thermal stability of studied glasses against crystallization is in order (a) < (b), i.e. the system Li2O - 2SiO2 - 0.1NiO
is more stable against crystallization than Li2O - 2SiO2 system. The addition of NiO to Li2O - 2SiO2 system increases
its thermal stability. The results indicate that the sequence thermal stability of the studied system of glasses vs.
crystallization depends not only on their composition but also on the used criteria.
V tejto publikácii sa skúmala termická stabilita skiel patriacich do základneého system Li 2O - 2SiO2. Na
vyhodnotenie termickej stability oxidových skiel voči kryštalizácii bolo použité kritérium založené na dĺžke indukčnej
periódy kryštalizácie. Platnosť tohto kritéria bola vyšetrená u sústav skiel Li2O - 2SiO2 a Li2O - 2SiO2 - 0,1NiO.
Zistilo sa, že systém Li2O - 2SiO2 - 0,1NiO je stabilnejší ako Li2O - 2SiO2. Mnohí autori hodnotili stabilitu skla na
základe charakteristických teplôt DTA a DSC kriviek, kryštalizačnej aktivačnej energie alebo kryštalizačnej
rýchlostnej konštanty. V tejto publikácii kritérium pre hodnotenie termickej stability vychádza z indukčnej periódy
kryštalizácie a bolo aplikované na skúmané systémy. Ako základ bol použitý Li2O - 2SiO2, pretože mechanizmus
kryštalizácie môže byť relatívne jednoduchý. Termická stabilita študovaných skiel je v poradí Li 2O - 2SiO2 < Li2O 2SiO2 - 0,1NiO. Je to v súlade s poriadkom určujúcim stabilitu kritéria založeného na charakteristických teplotách.
Výsledky ukazujú, že postupnosť termickej stability systému študovaných skiel voči kryštalizácii závisí nielen na ich
zložení ale aj na použitom kritériu.
The critical issue for the existing or potencial
applications of glasses is their thermal stability
towards crystallization. They should be stable
towards thermal aging during their application. On
the other hand, those glasses that serve as
intermediate products for fabricating glass – ceramics
are expected to possess an appropriate thermal
stability [1, 2]. Therefore, it is very important to
evaluate the thermal stability of glasses vs.
crystallization.
Experiment
Preparation of glasses
Analytical grade reagents Li2CO3, SiO2 and NiO in a mole
ratio Li2O - 2SiO2 and Li2O - 2SiO2 - 0.1NiO were mixed
by ball – milling and then melted in a platinum crucible at
~ 1400 °C for 2h. The melts were quenched by pouring
into a cold steel mold.
Instruments
Many authors based the evaluation of glass stability
employing the characteristic temperatures of DTA
and DSC curves, crystallization activation energy or
crystallization rate constant [3, 4]. These stability
criteria are not fixed physical parameters, since they
depend on the heating rate and temperature.
In this paper, a criterion for evaluating the thermal
stability based on the induction period of
crystallization was applied [5] to the Li2O - 2SiO2 (a)
and Li2O - 2SiO2 - 0.1NiO (b) glasses. Lithium
disilicate system was chosen as a base because the
crystallization mechanism may be relative simple.
Thermal stability of glasses was studied using
computerized Derivatograph OD 102 (MOM Budapest).
DTA curves were measured in air using a platinum
crucible, about 150 mg of powdered samples with
a particle size 0.10 – 0.16 nm and heating rates of 10, 15,
20 and 25 °C were used.
Results and discussion
The values of induction period (τi) are given by Eq.(1) and
the parameters A and B by Eq.(2):
(1)
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Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
and
(2)
where the conversion αi corresponds to the end of
induction period, F(αi) is the conversion function, AK
is the pre-exponential factor, Ea is the activation
energy [2, 5].
In the fig. 1 we can see the DTA curves of investigated
glass systems. The resulting values of induction period
(τi), parameters A, B are listed in tab. 1 and the
temperature dependence of the lengths of induction
period for individual glasses is shown in fig. 2.
It can be seen that the thermal stability of the studied
systems is in order (a) < (b), i.e. the addition of NiO to
Li2O - 2SiO2 glass system increase its thermal stability.
Conclusions
In this paper the influence of added NiO oxide on the
thermal stability of Li2O - 2SiO2 glass system has been
studied by means of the induction period of
crystallization. The thermal stability of the studied glasses
is in order: Li2O - 2SiO2 < Li2O - 2SiO2 - 0.1 NiO. It is in
agreement with the order determined by the stability
criteria based on the characteristic temperatures.
Literature
The lenght of induction period τi and parameters A and B
for studied systems
Tab. 1 Dĺžka indukčnej periódy a parametre A a B študovaných
systémov
Tab. 1
System
A/min
B/K
τi/min-1
Li2O - 2SiO2
(a)
8.07.10-22
41150
5
Li2O - 2SiO2 –
0.1NiO (b)
6.30.10-21
40490
17.5
[1] TRICOT, G., REVEL, B., WEGNER, S. Thermal stability of a low
Tg phosphate glass investigated by DSC, XRD and solid state
NMR. J. Non – Crystal. Sol. 357, 2011, p. 2708–2712
[2] LENDVAYOVÁ, S., MORICOVÁ, K., JÓNA, E., KRAXNER, J.,
LODUHOVÁ, M., PAVLÍK, V., PAGÁČOVÁ, J., MOJUMDAR,
S.C. Thermal properties of oxide glasses. Part IV. Induction period
of crystallization as a criterion of thermal stability of M2O.SiO2 (M
= Li, Na) glass systems against crystallization. J. Therm. Anal. Cal.
108, 2012, p. 901–904
[3] CHENG, A., Criterion for evaluating the thermal stability of
glasses, J. Therm. Anal. Cal. 103, 1999, p. 8272–8276
[4] JÓNA, E., ŠIMON, P., NEMČEKOVÁ, K., PAVLÍK, V.,
RUDINSKÁ, G., RUDINSKÁ, E. Thermal properties of oxide
glasses. Part II. Activation energy as a criterion of thermal stability
of Li2O.2SiO2.nTiO2 glass systems against crystallization, J. Therm.
Anal. Cal. 84, 2006, p. 673–677
[5] ŠIMON, P., NEMČEKOVÁ, K., JÓNA, E., PLŠKO, A.,
ONDRUŠOVÁ, D. Thermal stability of glass evaluated by the
induction period of crystallization, Thermochim. Acta 428, 2005,
p. 11–14
Temperature/°C
Review: prof. Ing. Darina Ondrušová, PhD.
doc. Ing. Mariana Pajtášová, PhD.
Fig. 1 DTA curves of Li2O - 2SiO2 (a), Li2O - 2SiO - 0,1 NiO (b)
Obr. 1 DTA krivky of Li2O - 2SiO2 (a), Li2O - 2SiO - 0,1 NiO (b)
Temperature/°C
Fig. 2
The temperature dependence of the lengths of induction
period for studied glasses: Li2O - 2SiO2 (a), Li2O - 2SiO - 0.1 NiO
(b)
Obr. 2 Teplotná závislosť dĺžky indukčnej periódy pre študované
sklá: Li2O - 2SiO2 (a), Li2O - 2SiO - 0,1 NiO (b)
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Neželezné kovy a slitiny
Non-ferrous Metals and Alloys
neželezné kovy
a slitiny
Study of Copper Alloys by Atomic Force Microscopy
Štúdium zliatín medi použitím atómovej silovej mikroskopie
doc. Ing. Marta Kianicová, PhD., Ing. Dana Bakošová, PhD., Faculty of Industrial Technologies, University of
Alexander Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia
This work deals with the investigation of the surface of copper alloys by atomic force microscope (AFM). There is
the description of the samples as well as the description of constituent methods which were used in measurement.
AFM can be used for scanning the curves that show the dependence of interaction of the probe force and surface
of the sample in relation to distance between them – they are curves of approach/moving off. By using of
spectroscopic curve from the presented measurements, the homogeneity and ratio of Young modulus for copper
alloys were evaluated. For each sample, the creation of the curve was done by using of five different places – points.
We employed the general approximation and Sneddon's formula for analysis of data and calculation of Young’s
modulus of complete rake curve. The Sneddon’s model shows the relationship between load gradient, dP/dh, and
Young’s modulus E. Spectroscopy curves and following calculations revealed that the Young modulus of CuZn37 is
the 0.8693 times lower than Cu99,9E and the Young modulus of CuAl9Mn2 is the 0.7898 times lower than Cu99,9E.
Práca sa zaoberá štúdiom vlastností zliatin medi použitím atómového silového mikroskopu NT-206, ktorý spolu
s riadiacim programovým zabezpečením a prostriedkami spracovania AFM zobrazení je určený na meranie mikro
a submikroreliéfu povrchov, objektov mikro a nanometrových rozsahov s vysokým rozlíšením. Oblasti použitia AFM
NT-206 sú fyzika pevných materiálov, tenkovrstvové technológie, nanotechnológie, mikroelektronika, optika, výskum
precíznej mechaniky, vákuová technika, atď. Použitím AFM NT-206 je možné snímať krivky zobrazujúce závislosť
sily spolupôsobenia sondy a povrchu vzorky od vzdialenosti medzi nimi – sú to krivky priblíženia / oddialenia. Tieto
krivky sú dôležité na meranie vertikálnej sily prikladanej k povrchu zo strany hrotu v procese skenovania. Z krivky
môžeme okrem sily vyhodnotiť viskozitu zašpineného povrchu, hrúbku vrstvy pokrytia a tiež miestne variácie
pružných vlastností povrchu. Krivka priblíženia/oddialenia je grafickou závislosťou odklonu meracej konzolky od
predĺženia skenovacieho zariadenia. V práci sme použili všeobecnú aproximáciu používanú pre analýzu dát
a výpočet Youngovho modulu z celkového sklonu spektroskopickej krivky použitím Snedonnovho vzťahu, ktorú sme
vykonali na rôznych miestach vzoriek skúmaných zliatin medi. Sneddonov model dáva závislosť medzi záťažovým
gradientom dP/dh a Youngovým modulom E. Z porovnania údajov získaných zo spektroskopických kriviek sme
zistili, že modul pružnosti v ťahu zliatiny CuZn37 je 0,8693 násobok hodnoty modulu zliatiny Cu99,9E a modul
CuAl9Mn2 je 0,7898 násobok hodnoty modulu zliatiny Cu99,9E. Zliatina Cu99,9E má najväčšiu tuhosť.
Copper alloys have unique combinations of mechanical
and physical properties and excellent corrosion and
wear resistance and these attributes means that copper
and its alloys are the quite a good material choice for
building constructions, but it is also connected with the
use of copper in many demanding engineering
applications in the marine, automotive, chemical and
electronics industries. Continuing development trends
relating to superconductors, electric vehicles, solar
heating and large-scale desalination of water ensure that
copper could be still the essential material of the future.
Atomic-force microscope
Atomic-force microscope AFM NT-206 in a complex
with control and image processing software is intended
for measurement and analysis of surface micro and
submicro relief, objects of the micro and nanometer
range with high resolution [1].
The image of a surface in the AFM is obtained at
scanning a sample in a horizontal plane by a tip with the
curvature radius about tens–hundreds of nanometers
attached to the cantilever. A control system traces the
probe position in relation to the sample surface in every
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Neželezné kovy a slitiny
Non-ferrous Metals and Alloys
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
is known as “leap to contact”. Except of Van der Waals
attractive forces and electrostatic forces, there is a
compound influence of the surface moisture capillarity
as well as impurities and grease on the tip during the
working in air environment. Change of the force in the
part B–C of the curve can be related to the tip shrinkage
in accordance with the Hook law (F = -kΔx) what
allows to evaluate the thickness of absorbed layer on the
sample surface.
measurement point and it keeps the tip to sample
separation at constant level set by the operator. The
changes of the probe vertical position in every point
make an AFM data matrix which is recorded in a file
and then it can be used for further processing,
visualization and analysis [2].
Possibility of atomic-force microscope
Using AFM it is possible to scan curves that show
dependence of interaction of the probe composite force
and surface of the sample relating to distance between
them – they are curves of approach /moving off. These
curves are very important for measurements of vertical
force attached to the surface from the side of the tip in
the process of scanning. Besides the force it is also
possible to evaluate viscosity of dirty surface, thickness
of the covering layer and also local variations of elastic
properties of the surface from the curve.
Section C–D: This part characterizes further approach
of the probe to the sample and it is accompanied by
driving needle tip to the surface and moreover there is
nearly linear curve of the cantilever towards the surface.
From the shape of the C–D section we can evaluate
modulus of elasticity of the system probe–surface. In
the case that, for example, the measuring probe is much
softer than the surface of the sample, the curve
inclination presents mostly elastic constant of the
cantilever itself. Contrariwise, if the hardness of the
cantilever is much harder than the surface of the sample,
inclination of the section C–D allows us to study elastic
features of the sample. Section C–D does not have to be
straight line at all, the inclination change of this curve
part shows differences in surface reactions to different
attached force [3, 4].
The curves of approach / moving off that are obtained
seem to be specific for each sample enough and at the
same time we can separate general characteristic
sections in them, as shown in fig. 1.
Section D–E: Point D refers to the end of the
approaching phase and the beginning of moving-off
phase from the surface. If there is no hysteresis of the
scanning device the section D–E is practically the same
as the section of the curve C–D, which we obtained
during the approach. In the case that both of these
sections are straight and parallel they do not give us any
additional information (besides above mentioned). In
the case that they are unparallel it allows us to
determine plastic and elastic deformation of the sample
(if the speed of recovery of surface geometrical features
is slower than moving-off of the probe).
Section E–F: Point E refers to the neutral divergence of
the cantilever. During further moving-off of the probe
from the surface, the cantilever starts to incline to the
sample because adhesive or gravity force affects the tip.
The shape of the section E–F is influenced by presence
of absorbing layers on the sample surface. In the case of
the work in vacuum, Van der Waals and electrostatic
forces affect the tip of the needle. If we work at the air
conditions, quite strong capillary force of moisture on
surface layer, grease and impurities are added to these
forces. Thickness of the surface layer influences the
length of the section E–F and its inclination, which is
different to inclination caused by hardness of the
sample, and points to moving up absorbing layers
together with the moving-off probe. When the elastic
response of the cantilever outruns gravity forces of the
surface side and its layers, the probe separates from the
sample surface. Point F, known as the point of
separation, refers to this action in the curve of
approach/moving off.
Fig. 1 Nomograph of the curves – approach / moving off. The solid
lines are schematic presentation of curves obtained in
vacuum. Dashed lines show variations of curves of
approach/moving off subjected to elastic features of the
sample and by presence of surface layers of moisture and
impurities
Obr. 1 Kriky priblíženie / oddialenie. Plnou čiarou sú schematický
zobrazené krivky získané vo vákuu. Čiarkované čiary
ukazujú variácie kriviek priblíženia/oddialenia podmienené
pružnými vlastnosťami vzorky a prítomnosťou povrchových
vrstiev vlhkosti a šmúh (nečistôt)
Section A–B: In the left part of the curve there is
a scanning device completely moved off and the
cantilever is not bent because the tip is not in the contact
with the sample. By approaching the surface the
cantilever is not bent until the Van der Waals forces
start to act (point B). In this part the curve does not
contain any useful information.
Section B–C: In point B the cantilever suddenly starts
to move towards the surface and the tip starts to be in a
contact with the surface (point C). This part of the curve
64
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Neželezné kovy a slitiny
Non-ferrous Metals and Alloys
Section F–G: When the elastic response of the
cantilever outruns the gravity force of the surface and its
layers, the probe separates from the sample. In the curve
of approach/moving-off there is a point F, known as the
point of separation, referring to this mentioned above.
The size of straining in the point F is equal to the total
maximum adhesive force between the probe and sample
and provides key information on observation of
adhesion. If the moisture layer is covered enough with
grease layer or other impurities, it is the case when we
can observe not only one point of separation (F1 and F2).

(8)
The equations of line were obtained from spectroscopic
curves by approximation and their values and they are
presented in the tab. 1.
Tab. 1 The values of k1 and k2 obtained by approximation of
spectroscopic curves by assignment of line
Tab. 1 Hodnoty k1 a k3 z aproximácie spektroskopických kriviek
na priamku
k1-1
k1-2
k1-3
k1-4
k1-5
k1
-2.2747 -2.2753 -2.2698 -2.2787 -2.2688 -2.2735
k2-1
k2-2
k2-3
k2-4
k2-5
k2
-1.9802 -1.9742 -1.9713 -1.9811 -1.9752 -1.9764
k3-1
k3-2
k3-3
k3-4
k3-5
k3
-1.7996 -1.7945 -1.7912 -1.7925 -1.7998 -1.7955
Position of the points F1 and F2 depends on viscosity
and thickness of these layers. Transition between the
sections E–F and F–G does not necessarily have to have
steep ascent. In the case that the absorbing layer has
equal viscosity, the probe can move off from the surface
gradually and the transition E–F - F–G will have round
shapes.
By using of average values
k1 = -2.2735
k2 = -1.9764
k3 = -1.7955
Experiment
By using of spectroscopic curve from presented
measurements, the homogeneity and ratio of Young
modulus on copper alloys were evaluated. For each
sample was creation of the curve was done by using of
five different places – points.
k 2 E1 ,
k1
k3 E1 ,
E3 
k1
E2 
 
E2 
(1)

(2)
where E  1   m2  / Em  1   c2  / Ec  ,
is the compound elastic modulus, (E m, Ec, m, c
Young’s modulus and Poisson’s ratio of a material and
a cantilever, respectively), P - normal load, A - contact
area, h - the indentation depth.
(10)
E3 
k 3 E1  1.7955

E1
k1
 2.2735
E3  0.7898E1
Conclusions
Spectroscopy curves and following calculations
revealed that the Young modulus of CuZn37 is the
0,8693 times lower than Cu99,9E and
the Young
modulus of CuAl9Mn2 is the 0,7898 times lower than
Cu99,9E. From these surface topography and
spectroscopic curve it could be concluded that all used
samples are homogeneous.
The following formula 1 represents the modulus of two
different samples
dP1 2 A1 / 2
dP  1 / 2 ,
(3)
 1 / 2 E1  E1  1
dh1

dh1 2 A1 / 2
(4)
Literature
[1] WIESENDANGER, R. Probe Microscopy and Spectroscopy:
Methods and Applications, Cambridge, University Press, 1994
[2] WEISENHORN, A.L., HANSMA, P.K., ALBRECHT, T.R.,
QUATE, C.F. Forces in Atomic Force Microscopy in Air and
Water, Appl. Phys. Lett., 1989, 54(26), p. 2651–2653
[3] HUTTER, J.L., BECHHOEFER, J. Measurement and
manipulation of Van der Waals forces in atomic force
microscopy, Journal of Vacuum Science and Technology B, 1994,
12, p. 2251–2253
(5)
(6)
dh
dP1
 k1 and dP2  k 2 ,
dh1
dh2
k 2 E1  1.9764

E1
k1
 2.2735
E2  0.8693E1
1
dP2 2 A1 / 2
dP  1 / 2 .
 1 / 2 E2  E2  2
dh2 
dh2 2 A1 / 2
The relation of modulus of elasticity:
dP1  1/ 2
dP1
1/ 2
E1 dh1 2 A
E
dh

 1  1
E2 dP2  1/ 2
E2 dP2
dh2
dh2 2 A1/ 2
.
The linear equation is: y  kx  q , k  dP ,
(9)
where E1 – Young’s modulus of Cu99,9E, E2 – Young’s
modulus of CuZn37, E3 – Young’s modulus of
CuAl9Mn2
1

Cu99,9E
CuZn37
CuAl9Mn2
They are held for the comparison of samples modulus
We employed the general approximation and Sneddon's
formula for analysis of dates and calculation of Young’s
modulus of complete rake curve. The Sneddon’s model
gives the relationship between load gradient, dP/dh, and
Young’s modulus, E, in the form [3, 4]:
dP 2 A 2

E
dh  1 2
E1 k1

E2 k 2
[4] СУСЛОВ, А.А., ЧИЖИК, С.А.: Cканирующие зондовые
Микроскопы, Mатериалы технологии, инструменты, 1997,
№3, 78–79
(7)
Review: prof. Ing. Františka Pešlová, PhD.
doc. Ing. Ján Bezecný, CSc.
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Ekologie, recyklace, druhotné zpracování materiálu
Environmental Protection, Recycling, Secondary Material Processing
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
ekologie, recyklace,
druhotné zpracování
materiálu
Application of Textile Recycling in the Clothing Design
Aplikácia recyklovaných textílií v odevnom dizajne
doc. Ing. Pavol Lizák, PhD., University of Alexander Dubcek of Trencin, Faculty of Industrial Technology,
Department of Industry design, Ruzomberok, Slovakia
The process of backward utilization of materials, whether it is paper, glass, plastic or textiles it is nowadays very
actual topic for many art and design projects. The question is whether in this time when we have enough new and
good quality of textile materials actual process of using has determined throw away? The answers are the following
facts, which basically were created term works of the second year class students from Department of Industrial
Design in Ruzomberok, which abetted them to think about the acute issues of nowadays, but not only in the art. The
use of recycling materials, whether it is paper, glass, plastic, textiles is nowadays a very actual. This is a topic for
a number of art and design projects.
Proces spätného využitie materiálov, či už je to papiera, skla, plastov alebo textílií je dnes veľmi aktuálnou témou
pre viaceré umelecké a dizajnérske projekty. Otázkou je, či v tejto dobe, keď máme dostatok nových a kvalitných
textilných materiálov v súčasnom technologickom procese je potrebné využívať aj druhotné suroviny. Odpoveďou sú
nasledujúce odevy, ktoré boli vytvorené študentmi z katedry priemyselného dizajnu v Ružomberku a zároveň
pomáhali študentom premýšľať nielen v umení o akútnych problémoch súčasnosti. V období, keď snáď každý z nás
sa zaujíma o našu budúcnosť, rezonujú problémy zaplavenia našej planéty odpadom a preto je naliehavou
záležitosťou pre výrobcov vybrať ekologický vhodný materiál pre ich výrobok. Proces spätného využívanie
materiálov, či je to papier, sklo, plast, textil je v dnešnej dobe veľmi aktuálny. Je to témou aj pre viacerých
umeleckých a dizajnérskych projektov. Druhotné využitie textílií je teraz v súčasnosti známe pod názvom "second
hand" obchodmi a nostalgicky spomíname nie len na minulosť, keď vtedajšia generácia v čase keď podnikala
nemala rovnaké možnosti z pohľadu technológie a recyklácie ako dnes, keď napr. kvalitné oblečenie pre dnešnú
populáciu je možné z pohľadu odevného dizajnu vytvárať aj z recyklovaných materiálov.
In period, when perhaps every person who cares least
about our future, resonates the problems of flooded of
the planet's with waste of variable characters is an
urgent issue for the designer to choose what material to
their product. The process of backward exploitation
materials, whether is it paper, glass, plastic, textile it is
nowadays actual topic for many art and design projects.
Secondary utilization of the textile is now popularly
known perhaps as "second hand" shops and
nostalgically can remember no only one mother, as a
representative of the older generation at the time when
business did not offer as much as today, when they
quilted nightly clothing for their children and prepared
the actual models. The exemplary ecological attitude
had our ascendants. The used and discarded textiles they
used for the handcrafted indoor accessories. Our
grandmothers had in back side of rooms looms in which
they textured a carpets. Into the texture they
interweaved strips cut from an old clothing and housing
textiles. Quantity of beautifully patterned carpet, where
the patterns inherited and passed on to future
generations is still the treasury of the Slovak folk art.
Also, patch-work technique has it’s origins in
environmentally thinking of American settlers. The
inaccessibility of the new materials, and not only the
least difficult financial situation, and tendency to use
every piece of old textile wed with beauty and
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Ekologie, recyklace, druhotné zpracování materiálu
Environmental Protection, Recycling, Secondary Material Processing
imaginativeness of patterns, which had became the
inspiration of apparel and textile production for decades.
The utilization of recycling in the creative
process in creation of clothes
The issue of recycling textiles
The question is how can we do, each of individual,
whether consumer or producer influence the fact that the
planet's pollution and the accumulation of used textiles.
The responsible attitude is the reflection of educational,
cultural and moral maturity. It is important to incinerate
textiles since burning releases large amounts of
dangerous gases. Another of the principle is that we do
not accumulate unnecessarily used clothing and worn
clothing do not put into the containers, but for recycling
or give to charity.
Can it be in the time when we have enough of the
quality and new textile materials actual the current
treatment of textile materials already used and intended
for the scrap heap? As answers are term works of
students, which abetted them to think about the acute
issues of nowadays, but not only in the art.
At the beginning of this reflection we offer a few facts:
In Slovakia, yearly is produced more than 1.5 million
tones of household waste. It is the source of many
problems - polluting the environment, for its destruction
it is necessary to spend considerable funds. Municipal
waste is also a source of raw materials. The amount of
municipal waste in Slovakia is 463.2 kg per capita in an
year. Only 0.4 percent of the waste is used as secondary
raw material, 0.8 percent is processed as compost and
the rest 98.8 percent is unused, 7.4 percent is disposed
of by incineration and by land filling 91.4 percent.
Recycling prevents the waste of resources, reduces
energy consumption, in this way it contributing to
reducing greenhouse gas emissions. It is the trend of the
future, if we would not want to literally "get drowned"
in the waste and unnecessary wasted energy spent on
the disposal and subsequent production of new products
from new sources. They are not infinite.
We also pay attention to the problem of recycling when
we enter the topic term papers for the students of the
Department of Industrial Design. This experience were
preceding of teaching atelier creation of clothing, where
some students used to create models from older, already
retired pieces, they can take experiments with materials,
they did not afraid they spoil it. They used different
technologies from decolonization, dyeing and bleaching
with chlorine, cutting into small pieces and subsequent
pooling weaving, sewing and stitching. The finishing
was often pushing and hand painting, or needlework and
claiming. In the early development of each model or
collection is a reflection about a particular area of life
and human existence. Before the part of the design is
very important to sink into the visionary realm of
inspiration and finding incentives and resources which
then - an artist is transformed into another, uncommon
and original position. Currently this part of the
suspension and insight is captured in the notes and texts
that students connect to their work. They serve us to
better understanding of their purpose and main idea of
the whole collection. If the collection form has the
harmonious whole, each part of the work for all to
pursue this line of warp, drawing and modeling of
patterns from a choice of finishing materials
Nowadays are many of communities and organizations
in Slovakia which are connected to separate collection
of waste. Despite of the increasing generated amount of
waste, in our country separate collection are stagnated.
The paper accounts is for about 20 percent, 26.5 percent
is of glass, plastics is 8 percent, 5 percent is of metals of
the total and hazardous wastes constitute approximately
1 percent. Textiles of the waste consists only 4 percent,
but it can be secondarily processed in different ways.
Applications recycling materials in the
clothing design
One of the best knows of disposing of organic waste is
textile processing into new fibers and materials. In the
past graded wool and hemp cloth were used in the
manufacture of air letter pads, to the production of paper
for banknotes and stamps. The share of the harvest and
the quality of rags in the manufacture of special types of
paper also affects the final product quality. Nowadays
manufactured specialty papers containing textile fibers
are made of a textile, which comes directly from the
production, as technological waste (different cuts, poor
quality of products and etc.) Textiles recovered from the
population will be diversified because of pollution and
unusable. Secondarily textile is also used for the
production of the nonwovens, which can be used in
construction, agriculture and in the industry. Except
this, the textile fibers are added as a substitute for wood
pulp cardboard into the particle board. Textile scrap tore
into the small pieces we can also pressed with the
addition of cement for sound insulation and sound
absorption products.
Around us are many old things, which we can take and
prepare them new face. Forgotten material of blueprints
in the fig. 1 on beautiful coats of chest grandmother was
an impulse for the creation of collections. In which the
main principle is the game. The game because part of
clothing can be combined and create still generate new
variants. The author connected blueprint with the
contrasting white cotton and red parts of the old clothes
which were sentenced to the suspension and added red
ribbons.
67
Ekologie, recyklace, druhotné zpracování materiálu
Environmental Protection, Recycling, Secondary Material Processing
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Fig. 1 Blueprints recycling clothing
Obr. 1 Odev z recyklovanej modrotlače
In the fig. 2 is model of this collection became as the
reaction to unattractive synthetic material - perforated
PVC, which is used in bathrooms. His subsequent
recovery was very interesting. It is very good to
attainment pretty big and solid shapes. This contrast was
the main impulse – prefer ugly material for an
interesting and attractive object, which would fall and
covered the body, but could not be the traditional
clothing. The author has used contrasting materials for
the other models, especially soft tulle, which painted
with flowers template. They appear with the structure of
PVC painted holes in the stockings, belts, and unusually
for the men's jacket. Flower, the symbol of beauty,
nature and finiteness is in the contrast of the artificial,
often indelible and nature onerous with synthetic
materials from which is the most of the collection.
Fig. 3 Transformation recycling material in the clothing
Obr. 3 Transformácia recyklovaného materiálu v odeve
residential interiors. As the basic element he choose
curtain, it was chosen for its softness, and decorative
patterns, combined with a braid and decorative
materials. Curtains drape, pleat and composed to the
gentle hint of more to reach a large volume of dominant
elements, such as a collar, ruffle and "spur", which
continue to shape the patterns of garments. Since he
would not create a big contrast, paint these accessories
such as shades of base clothes.
Conclusions
Inconsiderable part of the selection creates the choice of
appropriate accessories and footwear, which may
further reinforce this intention. Initially uncertain vision
is gradually becoming the reality, the concrete shape.
The resulting object is a visual artifact, which operates
on our senses and feelings, but must answer the primary
function, which is protection and envelopment of the
body. From this derives we have another specifications
for clothing, like as functionality and comfort. From this
point of view, those clothes did not explore because it
was not the aim of this work.
Acknowledgement
We wish to thank the Slovak Grant Agency (KEGA: 002
TnUAD 4/2011) for the financial support.
Literature
Fig. 2 Clothing and the recycling synthetic material
Obr. 2 Odev a recyklovaný syntetický materiál
[1] BHASKARAN, B.: Podoby moderního designu, Slovart, s.r.o.,
Praha, 2007, ISBN 80-7209-864-0
All three concepts Renaissance - recycling – reflection
are pointed more or less show a single feature and that
is the author of "transformation" (fig. 3). Whether it's
reshaping the material transformation of society or even
yourself, based on the change. It can be aware of, or
derive from our mind. In this case, was a "random" or
rather subconscious choice of material and it inspired
further works with him. For the realization of the work
he used a large proportion of textiles which are used in
[2] LIZÁK, P.: Textilný dizajn, Dizajn n.o. Ružomberok, 2006, ISBN
80-969610-0-4, EAN 9788096961009
[3] Available from: www.enviro.gov.sk, 18.12.2012
Review: prof. Ing. Darina Ondrušová, PhD.
doc. Ing. Iva Sroková, CSc.
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Hutnické listy č.7/2012, roč. LXV
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Removal of Toxic Phenol Derivatives from Water Solutions by Using
Co-montmorillonite
Odstraňovanie toxických derivátov fenolu z vodných roztokov použitím
Co-montmorillonitu
prof. Ing. Eugen Jóna, DrSc., Ing. Róbert Janík, PhD., prof. Ing. Darina Ondrušová, PhD., doc. RNDr.
Mariana Pajtášová, PhD., Ing. Martina Loduhová, Ing. Zuzana Harmatová, Department of Material
Technologies and Environment, Faculty of Industrial Technologies, University of Alexander Dubček in Trenčín,
I. Krasku 491/30, 020 01 Púchov, Slovakia
Montmorillonite is a member of the smectic clays with layered structure and negatively charged surfaces. The
layered structure is formed by two tetrahedral sheets linked to an octahedral sheet. The removal of 2,4- and 3,5dimethylphenols (2,4- and 3,5-DMP) from water solutions by using Co-exchanged montmorillonite (Co-MMT) and
type of interactions between Co(II) and 2,4- or 3,5-DMP have been study. The results of RTG diffraction and IRspectra shows, that organic species are intercalated into the interlayer space of montmorillonite. The presence of
protonated or coordinated phenol derivatives is connected with different steric and electronic properties of phenol
derivatives (2,4-dimethylphenol or 3,5-dimethylphenol).
Výskum v oblasti využitia ílov na odstraňovanie škodlivých látok z vodných roztokov je aj v súčasnej dobe
intenzívny. Prírodný ílový minerál montmorillonit, vďaka svojej unikátnej vrstevnatej štrukúre, dokáže prijímať do
štruktúry rôzne organické látky. Štruktúru montmorillonitu tvoria vrstvy tetraédrov kremíka medzi ktorými sa
nachádza vrstva oktaédrov hliníka, zatiaľ čo v medzivrstovom priestore sa nachádzajú vymeniteľné katióny. Existuje
niekoľko spôsobov odstraňovania znečisťujúcich organických látok z vodných roztokov, pričom jeden zo spôsobov
odstraňovania je práve absorpcia. Táto práca sa preto zaoberá možnosťami Co 2+-montmorillonitu (Co-MMT),
eliminovať vybrané toxické deriváty fenolu z vodných roztokov. 2,4-dimetylfenol (2,4-DMP) a 3,5-dimetylfenol (3,5DMP) sú organické látky používané ako antioxidanty plastov a gumy, nachádzajú sa v čistiacich a dezinfekčných
prostriedkoch, farbách, mazacích olejoch atď. Eliminácia uvedených derivátov fenolu z vodných roztokov a vstup
týchto látok do štruktúry montmorillonitu bol pozorovaný pomocou RTG práškovej difrakčnej analýzy, kedy ako
dôkaz slúži nárast parametra medzivrstvovej vzialenosti montmorillonitu d 001. Podľa výsledkov IČ spektoskopie
a posunu jednotlivých absorpčných pásov v spektre možno predpokladať, že 2,4-DMP existuje v Co-montmorillonite
v protonizovanej forme, pričom 3,5-DMP môže existovať aj priamo koordinovaný ku katiónom Co 2+.
During the last years much study of the interactions
between clays and organic compounds was carried out
with the purpose of determing the extent of intercalation
and the type of bond between metal cations and the
adsorbed organic species [1, 2]. The principal
interactions between these compounds are of the acidbase type. Depending on the polarizing power of the
metal cations and the basic strength of the organic
species, these adsorbed components (e.g. phenol
derivatives) may be protonated, thus gaining a positive
charge, or may be coordinated directly to the cations [3].
Experiment
Less than 2µm fraction of bentonite from Jelšový Potok
was separated from a bulk sample and converted into
the monoionic Ca-form using standard method. The
crystalochemical formula of Ca-MMT is as follows:
Ca0,48[Si7,59Al0,41][Al3,06Fe0,34Mg0,63] (OH)4O20.
The monoionic form Co2+-MMT was prepared from the
Ca-MMT in a way that 10 g of Ca-MMT were added to
450 cm3 of a CoCl2 solution (c = 1 mol.dm-3). The
mixture was stirred for a short time and left to stand for
24 h. After decantation CoCl2 solution was added again
to the solid phase, stirred and left to stand as previously.
This procedure was repeated five times. The solid
product was then washed by water in order to remove
the Cl- anions and finally dried at 60 oC.
Phenol and substituted phenols are important chemicals
in the manufacture of synthetic resins, dyes,
pharmaceuticals and agrochemicals [4]. Phenolic
compounds are very harmful to organisms even at very
low concentration due to its toxicity, foul odour and
carcinogenic properties [5].
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Ekologie, recyklace, druhotné zpracování materiálu
Environmental Protection, Recycling, Secondary Material Processing
The interlayer distances from the X-ray diffraction
patterns and colour of studied samples are summarized
in table 1.
Tab. 1 Representative diffraction data and colour of Co-MMT and
adsorption products
Tab. 1 Dáta získané z RTG difrakčnej analýzy a farba čistého a
modifikovaného Co-MMT
Sample
Co-MMT
Co-MMT + 2,4-DMP
Co-MMT + 3,5-DMP
Fig. 1 Montmorillonite (author)
Obr. 1 Montorillonit (autor)
o
d001 / nm 2theta /
colour
1.49
5.95
weak blue
1.54
5.75
dark brown
1.56
5.7
yellow
After the interactions with phenol derivatives the basal
spacing (d001) increased from 1.49 (Co-MMT) to 1.54
nm (Co-MMT + 2,4-DMP) an 1.56 nm (Co-MMT +
3,5-DMP). The observed changes of (d001) and changes
in colour of prepared samples indicated, that phenol
derivatives are intercalated into the interlayer spaces of
montmorillonite [4 – 6].
The monoionic form Co2+-MMT was added to the water
solution of 2,4-DMP respectively 3,5-DMP and this
mixture were stirred for a 48 h at pH 6. Concentration of
3,5-DMP in water solution was exactly the half of their
maximum solubility.
Analytical methods and equipments
Co-MMT
Co-MMT + 3,5-DMP
11600
The X-ray diffraction profiles for pressed powder
samples were recorded on a Philips PW 1050
diffractometer using CuKα radiation.
10100
Intensity
8600
The infrared absorption spectra were recorded with
Nicolet Magna 750 Fourier Transform IR spectrometer
in the range of 4000 – 400cm-1.
Co-MMT + 2,4-DMP
7100
5600
4100
2600
Results and discussion
1100
4
4,5
5
5,5
6
6,5
7
7,5
8
8,5
9
2θ/o
A precious information about the type of interaction
between the adsorbed phenol derivatives and Co-MMT
can provide X-ray analysis combined with IR-spectra.
In this paper we directed the attention of the
dimethylderivatives of phenol:
Fig. 4 Changes in XRD diffraction data of prepared samples
Obr. 4 Zmeny v RTG difrakčných záznamoch pripravených vzoriek
In infrared spectra of pure Co-MMT several peaks can
be observed that were attributed to the stretching
vibration of O-H groups (~ 3628 – 3629 cm-1) and water
(~ 3376 – 3418 cm-1), stretching vibration of Si-O
groups (~ 1035 – 1036 cm-1), AlAlOH (~ 914 – 916 cm1
), AlMgOH (~ 835 – 843 cm-1), deformation vibrations
of Al–O–Si groups (~ 521 – 522 cm-1) and Si–O–Si (~
465 – 466 cm-1) [6, 7] .
From infrared (IR) spectra follow [4 – 7] that the ring
vibrations of pure phenol derivatives (2,4-DMP: 1724
cm-1, 1614 cm-1 1512 cm-1; 3,5-DMP: 1620 cm-1, 1598
cm-1) shift to lower and higher frequencies when
accept a proton from the acid species (water molecules
serve as proton donors). The shift of these peaks of the
Co-MMT + 2,4-DMP (1722 cm-1, 1643 cm-1 or 1515
cm-1) supports the assumption that 2,4-DMP exist in
protonated form. The two bands at ~ 1620 cm -1 and
1598 cm-1 in the 3,5-DMP, which are not change after
intercalation, indicate the possibility of coordination of
3,5-DMP to Co2+ cations [3].
Fig. 2 2,4-dimethylphenol (2,4-DMP)
Obr. 2 2,4-dimetylfenol (2,4-DMP)
Fig. 3 3,5-dimethylphenol (3,5-DMP)
Obr. 3 3,5-dimetylfenol (3,5-DMP)
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Conclusions
Transmittance / %
X-ray powder diffraction and IR-spectra shown that 2,4DMP and 3,5-DMP are successfully intercalated into the
interlayer space of Co2+-MMT. The different
interactions of phenol derivatives may be connected
with different position of methyl groups on the phenol
ring (different steric and electronic properties of
individual DMP).
Literature
[1] LIU, R., FROST, R.L., MARTENS, W.N., YUAN, Y. Synthesis,
characterization of mono, di and tri alkyl surfactant intercalated
Wyoming montmorillonite for the removal of phenol from
aqueous systems. J. Colloid Interface Sci., 2008, 327, p. 287–
294
3,5-DMP
[2] JÓNA, E., SAPIETOVÁ, M., ŠNIRCOVÁ, S., PAJTÁŠOVÁ,
M., ONDRUŠOVÁ, D., PAVLÍK, V., LAJDOVÁ, Ľ.,
MOJUMDAR, S.C. Characterization and thermal properties of
Ni-exchanged montmorillonite with benzimidazole. J. Therm.
Anal. Calorim. 2008, 94(1), p. 69–73
2,4-DMP
1900 1800 1700 1600 1500 1400 1300 1200 1100
Wavelength / cm-1
[3] YARIV, S. Thermo – IR spectroscopy analysis of the
interactions between organic pollutants and clay minerals.
Thermochim. Acta 1996, 274, p. 1–35
Fig. 5 Infrared spectra of pure 2,4- and 3,5-DMP
Obr. 5 Infračervené spektrá čistého 2,4- a 3,5-DMP
[4] OVADYAHU, D., YARIV, S., LAPIDES, I., DEUTCH, Y.
Mechanochemical adsorption of phenol by TOT swelling clayminerals I. – thermo-IR-spectroscopy and X-ray study. J. Therm.
Anal. Calorim. 1998, 51(2) , p. 415–430
Transmittance / %
[5] AGHAV, R.M., KUMAR, S., MUKHERJEE, S.N. Artificial
neural network modeling in competitive adsorption of phenol and
resorcinol from water environment using some carbonaceous
adsorbents. J. of Hazardous Materials. 2011, 188, p. 67–77
[6] JÓNA, E., RUDINSKÁ, G., SAPIETOVÁ, M., PAVLÍK, V.,
DRÁBIK, M., MOJUMDAR, S.C. Interactions of different
heterocyclic compounds with monoionic forms of
montmorillonite. J. Therm. Anal. Calorim. 2007, 90(3) , p. 687–
691
Co-MMT
[7] JANÍK, R., JÓNA, E., PAJTÁŠOVÁ, M., ONDRUŠOVÁ, D.,
LIZÁK, P., PAVLÍK, V., DURNÝ, R., MOJUMDAR, S.C.
Thermal spectral, and diffraction properties of Co-exchanged
montmorillonite with 2-, 3-, and 4-hydroxyphenol. J. Therm.
Anal. Calorim. 2012, 108( 3), p. 915–919
Co-MMT + 2,4-DMP
Co-MMT + 3,5-DMP
3100
2950
2800
[8] OGAWA, M., KURODA, K., KATO, CH. Preparation of
montmorillonite – organic intercalation compounds by solidsolid reactions. Chem. Letters. 1989, 18(9), p. 1659
2650
Wavelength / cm-1
Fig. 6 Changes in infrared spectra of Co-MMT after interaction
with 2,4-DMP and 3,5-DMP
Obr. 6 Zmeny v infračervených spektrách Co-MMT pred
a po interakcii s 2,4 a 3,5-DMP
Review: prof. Ing. Tatiana Liptáková, PhD.
doc. Ing. Iva Sroková, CSc.
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Hutnické listy č.7/2012, roč. LXV
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Removal of Iron from Aqueous Solutions Using a Modified Zeolite
Odstraňovanie železa z vodných roztokov pomocou modifikovaného zeolitu
prof. Ing. Darina Ondrušová, PhD., Ing. Michaela Ďurčeková, Ing. Lenka Špániková, Ing. Slavomíra
Domčeková, Ing. Martina Čechová, Faculty of Industrial Technologies in Púchov, University of Alexander
Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia
The presented work deals with the preparation of modified forms of natural zeolite and their environmental
application in the process of removing Fe from water solutions. The environment including water is exposed to
heavy metals for the long term. Typically, industrial activities are the source of heavy metals penetrating to the
environment. One of the possibilities of partial solutions of the problem is the use of natural minerals based on
zeolite. Due to their physico-chemical properties arising from their unique three-dimensional cavity structure, these
natural nanomaterials are suitable for all partial detoxification of the environment. Enriching the zeolite surface
with particles, for example Fe3O4-magnetit, can improve its adsorption capacity, and allow its use for the wide
spectrum of substances. Natural zeolite was modified by magnetic particles of magnetit for the level sufficient for
their removal from water solutions by magnetic separation.
Práca je zameraná na prípravu modifikovaných foriem prírodného zeolitu obohatených časticami magnetitu a ich
využitie v procese odstraňovania železa z vodných roztokov. Prírodné a syntetické zeolity majú unikátne štruktúrne,
fyzikálne a chemické vlastnosti, ktoré ich predurčujú pre využitie v mnohých technologických, poľnohospodárskych
a ekologických procesoch. Zeolity patria do skupiny hlinitokremičitanov s trojrozmernou dutinovou štruktúrou
tvorenou tetraédrami SiO4 a AlO4, vzájomne pospájanými atómami kyslíka. Vyznačujú sa výbornými adsorpčnými
a katióno-výmennými vlastnosťami. V mnohých prípadoch je výhodné obohatiť povrch zeolitu iónmi a časticami,
ktoré zvýšia jeho adsorpčnú kapacitu, resp. umožnia jeho použitie aj pre látky, ktoré sa na neupravený zeolit
neadsorbujú. Modifikácia pomocou magnetických častíc, okrem zvýšenej kapacity pre adsorpciu, obohatí zeolit aj
o magnetické vlastnosti. Takto modifikovaný zeolit ponúka výhodu jednoduchej separácie v magnetickom poli, čo
má veľký význam z hľadiska regenerácie adsorbentu. Výhodou použitia oxidov železa, magnetitu (Fe3O4), alebo
maghemitu (γ-Fe2O3), ako magnetického modifikačného prvku je okrem magnetických vlastností aj ich termická
a chemická stabilita.
Zeolites are widespread and their wealth of crystal
shapes, colors one mineral type and occurrence are very
diverse group of minerals. Zeolites form a group of
hydrated silicates with a spatial structure. They belong
to a group of tectosilicates [1]. The basis of crystal
structure is formed by tetrahedrons [SiO4]4-, which are
interconnected by a common oxygen ions. Silicon in
tetrahedron can be partially replaced by aluminum ion
(fig. 1).
Fig. 1 Structure of zeolite
Obr. 1 Rámcová štruktúra zeolitov [2]
The general chemical formula of zeolites can be
expressed as follows:
The voids may be given only those substances whose
molecules have a diameter smaller or equal to the
diameter of duct inlet openings. Molecules which are
larger than the diameter of the channels do not pass
cavities [3].
MxDy[Alx+2ySin-(x+2y)O2n] . mH2O
where Mx and Dy are important cations of monovalent
[Mx] and divalent [Dy] elements, offsetting negative
charge, which arises due to substitution Si4+ and Al3+.
The monovalent elements are frequently present Na,
occasionally also K, from divalent Ca, rarely Ba a Sr,
occasionally Mg and Mn too.
Natural zeolite channel diameters vary from 0.2 nm to
0.7 nm.
Quantity and selectivity cations bound to zeolite,
dependent on a number of factors, the most important
are pH, the structure of zeolite, electrolyte, the presence
of other ions and the time of adsorption.
In many cases it is advantageous to enrich the surface of
the zeolite particles and the ions to increase the
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Environmental Protection, Recycling, Secondary Material Processing
adsorption capacity or they are used for substances that
are unadjusted for non-adsorbing zeolite. Modification
with magnetic particles increases capacity of adsorption
and zeolite acquires the magnetic properties. Thus, the
modified zeolite offers the advantage of easy separation
in a magnetic field and this is very important for
regeneration of adsorbent.
One of the most popular ways of modification of
magnetic particles, zeolites are zeolite surface treatment
using magnetic metal nanoparticles (Fe, Co, Ni). The
advantage of using iron oxide, magnetite (Fe3O4), or
maghemite (γ-Fe2O3), to magnetic element in addition
to modify the magnetic properties of their thermal and
chemical stability [4].
Fig. 2 The time change of final Fe concentration in aqueous solution
after sorption using modified zeolite (grain size 0.25 - 0.4
mm)
Obr. 2 Časová zmena výslednej koncentrácie Fe vo vode po sorpcii
s použitím modifikovaného zeolitu (zrnitosť 0,25 - 0,4 mm)
Experiment
For the experiment we used the natural zeolite
clinoptilolite from site of Nižný Hrabovec. Crushing
and sieve analysis was used, we have prepared the
following fractions of clinoptilolite:
 0.25 – 0.40 mm
 0.40 – 0.63 mm
 0.63 – 1.00 mm
We modified natural zeolite particles of magnetite
Fe3O4. The natural zeolite were added to water solutions
FeCl3 and FeSO4 with the reaction ratio Fe3+ : Fe2+ = 2.
After heating the mixture to 70 °C is magnetite
precipitated solution NH4OH with equation:
Fig. 3 The time change of final Fe concentration in aqueous solution
after sorption using modified zeolite (grain size 0.4 - 0.63
mm)
Obr. 3 Časová zmena výslednej koncentrácie Fe vo vodnom roztoku
po sorpcii s použitím modifikovaného zeolitu (zrnitosť 0,4 0,63 mm)
FeSO4.7H2O + 2FeCl3.6H2O + 8NH4OH →
Fe3O4 + (NH4)2SO4+ 6NH4Cl + 23H2O
The mixture was decanted into pH = 6.5, then filtered
and dried. The procedure was applied to all three
particle sizes of zeolite.
Samples prepared by modified zeolite were used for the
removal of iron ions from the aqueous solution by
adsorption. The concentration of iron in aqueous solution
before and after sorption on zeolite was determined by
spectrophotometric method of calibration lines.
Results and discussion
Fig. 4 The time change of final Fe concentration in aqueous solution
after sorption using modified zeolite (grain size 0.63 - 1 mm)
Obr. 4 Časová zmena výslednej koncentrácie Fe vo vodnom roztoku
po sorpcii s použitím modifikovaného zeolitu (zrnitosť 0,63 1 mm)
Zeolite modified by magnetite particles was used for
removal of iron cations from aqueous solution. Aqueous
solution of iron was mixed with factions modified and
the natural zeolite for the sorption of iron ions in the
structure of zeolite. In some intervals: ½, 1, 2, 3, 5, 8
and 24 hours they were sampled and the aqueous
solution was determined by the concentration of iron
sorption of the zeolite. The original Fe concentration in
aqueous solution was 10.7181.10-5 mol.dm-3. The final
iron concentration in aqueous solutions for each sorption
time and three fractions of modified zeolite described in
graphic addictions can be seen in figs. 2 – 4.
The graphical relationships above show that the sorptive
capacity of modified zeolite decreases with increasing
particle size of zeolite, which is caused by reducing the
specific surface of the zeolite. The highest sorption
efficiency showed a modified zeolite with grain size
0.25 - 0.4 mm. The measurement results show that the
concentration of Fe with increasing sorption time
initially decreases. After eight hours of sorption
concentration of Fe in solution transiently increases and
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then decreases again to a value of 1.3444.10 -5 mol.dm-3
after 24 hours by sorption. The results confirmed the
ability of zeolite-containing magnetite Fe ions sorption
from aqueous solutions.
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From the graphical dependences in figs. 5 – 7 it follows
that natural zeolite in relation to modified zeolite
showed a higher sorption capacity for all assessed
sorption times in the case of grain size from 0.25 to
0.4 mm. In the cases of larger grain size of both
evaluated forms of zeolite (0.4 - 0.63 mm and 0.63 1 mm), after 24 hours of sorption the modified zeolite
showed increased sorption efficiency compared to the
natural zeolite.
In the next part of experiment the sorption efficiency of
modified zeolite with magnetite particles was compared
with efficiency of natural zeolite - clinoptilolite.
Comparison of the Fe concentration in aqueous
solutions after the sorption on natural and modified
zeolite, for different zeolite grain size show graphical
dependencies in figs. 5 – 7.
Conclusions
Three samples of modified zeolite were enriched by
magnetite particles with different grain size, and they
were used for removal of iron from aqueous solution.
Sorption capacity of modified zeolite was compared
with the sorption capacity of natural zeolite clinoptilolite. From the results of measurements follows
that the possibility of application of the modified
zeolite with particles of magnetite in the process of
removing iron ions from aqueous solutions has the
highest efficiency after 24 hours of sorption, with the
grain size from 0.25 to 0.4 mm. It can be concluded that
modified zeolite at timed intervals kept sorption
properties comparable with natural zeolite. Modified
zeolite also has the magnetic properties that allow its
easier separation from aqueous solutions by means of
magnetic field.
Fig. 5 Comparison of Fe concentration in aqueous solution after
sorption using natural and modified zeolite (grain size 0.25 0.4 mm)
Obr. 5 Porovnanie výslednej koncentrácie Fe vo vodnom roztoku po
sorpcii s využitím prírodného a modifikovaného zeolitu
(zrnitosť 0,25 - 0,4 mm)
Acknowledgement
The authors are grateful to the Slovak Grant Agency
VEGA 1/0530/11 for financial support.
Literature
[1] BRYCH, P. Zeolity. 2005.
http://www.zeolity.brych.cz
[online]
Dostupné
na:
[2] BELL, R.G. What are Zeolites?. [online] Dostupné na:
http://www.bza.org/zeolites.html
[3] DOMARACKÝ, D., RYBÁROVÁ, L. Obohatené prírodné
zeolity – minerálne hnojivo. Acta Montanistica Slovaca. Roč. 6,
č.5, 2001, s. 52-55
Fig. 6 Comparison of Fe concentration in aqueous solution after
sorption using natural and modified zeolite (grain size 0.4 0.63 mm)
Obr. 6 Porovnanie výslednej koncentrácie Fe vo vodnom roztoku po
sorpcii s využitím prírodného a modifikovaného zeolitu
(zrnitosť 0,4 - 0,63 mm)
[4] MATIK M. Možnosti modifikácie zeolitu oxidmi železa a jeho
využitia pri odstraňovaní Pb(II) z vodných roztokov. Acta
Montanistica Slovaca. Roč. 9, č.4, 2004, s. 418-422
Review: doc. Ing. Mariana Pajtášová, PhD.
prof. Ing. Tatiana Liptáková, PhD.
Fig. 7 Comparison of Fe concentration in aqueous solution after
sorption using natural and modified zeolite (grain size 0.63 1 mm)
Obr. 7 Porovnanie výslednej koncentrácie Fe vo vodnom roztoku po
sorpcii s využitím prírodného a modifikovaného zeolitu
(zrnitosť 0,63-1 mm)
74
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Koroze
Corrosion
koroze
__________________________________________________________________
Changes in Microstructure of Selected Diffusion Coatings after Hot Corrosion
Zmeny mikroštruktúry po vysokoteplotnej korózii vybraných difúznych
povlakov
doc. Ing. Marta Kianicová, PhD., Ing. Ján Kafrík, Ing. Jaroslav Trník, Faculty of Industrial Technologies,
University of Alexander Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia, Ing. Ondřej Dvořáček,
PBS Velká Bíteš, a.s., Vlkovská 279, 595 12 Velká Bíteš, Czech Republic.
Corrosion characteristics of aluminide and Cr modified aluminide diffusion coatings are compared in the paper.
Aluminide coatings are often applied on nickel superalloy in the order to increase the high temperature oxidation
resistance created by a protective heat-activated Al2O3 layer which acts as a protective barrier separating superalloy
from aggressive factors in the environment. Cr additions to β – NiAl compounds improve the coating resistance to hot
corrosion. Since in the chromaluminide coatings Cr occurs not only in the form of precipitates, but it is also in the
solid solution with nickel and aluminium in β – NiAl and it should be used as prevention of martensitic transformation
of nickel rich β – NiAl. Hot corrosion is the accelerated oxidation of a material at elevated temperature induced by
a thin film of fused salt deposit. Coatings were deposited on samples of superalloy IN 713 LC by method out –of –
pack and tested in Na2SO4 corrosive environments at temperature 920 °C at Silesian University of Technology in
Katowice, Poland. Macro and microstructure of the samples were evaluated by SEM with EDX microanalysis.
V článku sú porovnané korózne charakteristiky aluminidných Al a modifikovaných Al+Cr difúznych povlakov.
Aluminidné povlaky sú často aplikované na niklové superzliatiny z dôvodu zvýšenia vysokoteplotnej oxidačnej
odolnosti, vytvorením ochrannej tepelne aktivovanej vrstvy Al2O3, ktorá pôsobí ako ochranná bariéra oddeľujúca
superzliatinu od agresívnych činiteľov v prostredí. Prísada Cr umožňuje zvýšiť odolnosť aluminidných povlakov
voči korózii za teplôt v rozmedzí 815 až 920 °C. Skúmané povlaky boli deponované na vzorky zo superzliatiny IN
713 LC metódou out-of-pack a otestované v koróznom prostredí Na2SO4 za teplôt 920 °C na Polytechnike Slazskej
v Katowiciach, Polsko. Makro a mikroštruktúrne analýzy z povrchov a rezov jednotlivých vzoriek boli hodnotené na
SEM Hitachi a pomocou EDX mikroanalýzy. Makroskopickou analýzou všetkých vzoriek sa ukázalo, že Inconel
713 LC bez povlaku vykazuje najväčšie korózne napadnutie. Porovnaním povrchu vzoriek s Al a (Al+Cr) povlakom
vyplýva, že sú makroskopicky vzhľadovo podobné a korózne zlúčeniny nezasahujú do takej hĺbky ako u vzorky bez
povlaku. Vzorka s (Al+Cr) povlakom mala najrovnomernejšie rozloženie koróznych zlúčenín Na a S. Na základe
získaných výsledkovmôžeme skonštatovať, že pri porovnaní koróznych charakteristík vzorky bez povlaku, s Al povlakom a (Al+Cr) povlakom, výsledky hovoria v prospech (Al+Cr) povlaku. Výsledky práce môžu slúžiť ako
podklad pre ďalší vývoj povlakov na turbínové lopatky leteckých motorov pre firmu První Brnenská Strojírna a.s.,
ktorá vyrába prúdové a turbovrtuľové motory pre bezpilotné lietadlá, ľahké športové lietadlá a ultralighty.
Hot corrosion is the accelerated oxidation of a material
at elevated temperature induced by a thin film of fused
salt deposit. Fused Na2SO4, which is the dominant salt
involved in hot corrosion, is an ionic conductor, so that
the corrosion mechanism is electrochemical in nature.
Al2O3 layer acts as a protective barrier separating
superalloy from aggressive factors in the environment
[1]. Since Cr increased Al activity in Ni – Al system,
the β – NiAl phase containing Cr should tolerate greater
Al depletion before NiO begins to form on the surface
[2 – 4]. The acid/base nature of this oxyanion salt offers
the possibility for the dissolution of the normally
protective oxide scale [5]. The hot corrosion
morphology is typically characterized by a thick, porous
layer of oxides with the underlying alloy matrix
depleted in chromium and followed by creating of
internal rich chromium sulphides [6]. Because of its
high thermodynamic stability, Na2SO4 is found to be the
common or dominant component of the salt deposit.
Sulphur is a principal impurity in fossil fuels, and
sodium is introduced into the combustion air, usually in
an aerosol originating from seawater.
75
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Koroze
Corrosion
Tab. 1 Process of the test
Tab. 1 Priebeh testu
Experiment of the hot corrosion test
Characteristic of samples
IN 713 LC
Three types of samples were used for the hot corrosion
test. Substrates for all samples were made of Ni –
superalloy IN 713 LC. First sample was superalloy
without coating. Second kind of sample was composed
from superalloy substrate with aluminide NiAl coating
and third type was substrate by Cr modified
aluminide coating.
IN 713 LC +
Al + HT
IN 713 LC +
(Al+Cr) +
HT
start
Before deposition the samples with coatings were sand
blasted from reason of better adherence of coating to the
substrate. Deposition of coatings was performed by the
out of pack method, at 1050 °C, for 6 hours and
thickness of coatings was in the range (55 ± 5) μm. Heat
treatment (HT) was made after coating deposition for 4
hours at temperature 950 °C and the samples were
cooled in furnace. The tablets of Na2SO4 were used as
corrosion salts because they are the dominant salts
involved in hot corrosion.
1h
4h
55 h
Technique of the test and next evaluation
The aim of test was to compare hot corrosion behaviour
of three types of samples. Tablets of Na2SO4 (0.3 g)
were inserted into the samples (see tab. 1) and their
function was to create corrosive environment. Six pieces
(two samples of each type were used) were placed in the
furnace and heated at 920 °C. During heating the pieces
were taken from furnace after repetitive time cycles,
photographed and placed back. Total time of the test
takes 101 hours (tab. 1). After ending of the test, the
samples were cut (fig. 1) and electron microanalysis
was used for evaluation of the surface and cross sections
of samples.
101 h
Discussion
Microphotograph of cross-section of all samples (fig. 2 4) with indicated rectangles for EDS analysis give us
information about chemical contents of the elements
(tab. 2 - 4).
a)
Fig. 2a) Decohesion of sublayers
Obr. 2a) Dekohézia podvrstiev
b)
c)
Fig. 1 Cross – sections of samples after test, a) IN 713 LC, b)
IN713 LC + Al coating, c) IN 713 LC + (Al+Cr) coating
Obr. 1 Prierezy vzoriek po teste, a) IN 713 LC, b) IN713 LC + Al
povlak, c) IN 713 LC + (Al+Cr) povlak
Fig. 2b) Cross – section of sample without coating
Obr. 2b) Prierez vzorky bez povlaku
76
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ISSN 0018-8069
Koroze
Corrosion
Tab. 2 Wt. % of elements in areas indicated on fig. 2
Tab. 2 Hm. % prvkov v plochách podľa obr. 2
wt. % Al-K S-K
Cr-K Ni-K
Evaluation plane analysis of cross - sections of samples
for Na and S compounds was carried out in this way:
Sample with Al coating has the most wt. % of corrosion
Na and S compounds under surface. Sample with
(Al+Cr) coating has more steady distribution of Na and
S compounds in comparison to Al coating. Substrate
plane analysis of sample with (Al+Cr) coating did not
showed the presence of corrosion compounds Na and S
near the interface substrate/corrosion compounds, but
the sample with Al coating showed the presence of both.
S and Na penetrate deep under the surface and fix the
elements from substrate. This represents the form of
decohesion which lead to micromechanism of following
spalling. The best cohesion characteristics were
observed for samples with modified (Al+Cr) coating.
Nb-L Mo-L
1
7.2
-
8.3
81.6
2.8
-
2
9.3
10.1
17.8
62.8
-
-
3
8.8
18.1
17.6
55.6
-
-
4
3.1
-
2.1
88.1
-
6.7
Conclusions
On the basis of results we can conclude that corrosion
characteristics of samples with (Al+Cr) coatings are
better than samples with Al coating. Results show
benefits of Cr to aluminide coating.
Fig. 3 Cross – section of sample with Al – coating
Obr. 3 Prierez vzorky s Al – povlakom
Tab. 3 Wt. % of elements in areas indicated on fig. 3
Tab. 3 Hm. % prvkov v plochách podľa obr. 3
wt. %
Na-K
Al-K
S-K
Cr-K
Ni-K
1
8.9
2.8
2.5
11.4
74.4
2
32.8
6.1
17.2
16.0
25.4
3
7.1
4.2
2.0
11.7
74.8
16.6
79.1
4
5
4.3
2.2
6
Literature
Mo-L
[1] TONG, L., DENGZUNG, Y., CHUNGEN, Z. Low - temperature
Fomation of Aluminide Coating on Ni – base Superalloys by
Pack Cementation Process. Chinese Journal of Aeronautics.
2010, no. 23, p. 381-385. ISSN 1000-9361
[2] BOSE, S. High temperature Coatings. Elsevier Science &
Technology Books, 2007. 299 p. ISBN 0750682523
9.4
2.0
23.2
56.3
5.7
4.2
3.5
5.3
85.7
1.3
[3] GODLEWSKA, E., GODLEWSKI, K. Chromaluminizing of
Nickel and Its Alloys. Oxidation of Metals. 1984, vol. 22, no.3/4.
p. 117 – 131
[4] RAPP, R.A. Pack cementation aluminide Coatings on
Superalloys. Codeposition of Cr and Reactive Elements, Grant
No. N0001 4-90-J-1 765, 1992
[5] RAPP, R.A. Hot corrosion of materials: a fluxing mechanism?
Corrosion Sciencie. 2002. vol.44. no.2, p. 209 – 221
[6] LAI, G.Y. High – Temperature Corrosion And Materials
Applications. ASM Interanational. 2007, 455 p. ISBN 0-87170853-1
Review: prof. Ing. Františka Pešlová, PhD.
doc. Ing. Ján Bezecný, CSc.
Fig. 4 Cross – section of sample with (Al + Cr) coating
Obr. 4 Prierez vzorky s (Al + Cr) povlakom
Tab. 4 Wt. % of elements in areas indicated on fig. 4
Tab. 4 Hm. % prvkov v plochách podľa obr. 4
wt. %
Na-K
Al-K
S-K
Cr-K
Ni-K
1
1.6
11.2
0.3
31.2
55.0
2
2.0
3
8.8
7.0
3.1
16.1
63.7
4
9.8
6.7
3.0
25.8
54.4
5
4.2
11.3
4.3
37.6
34.7
6
13.4
10.1
7.4
34.5
26.0
1.2
88.4
7
97.3
3.0
Mo-L
0.7
7.4
77
Povrchová úprava
Surface Treatment
Hutnic ké listy č.7/2012, roč. LXV
ISSN 0018-8069
povrchová
úprava
_____________________________________________________________________________________________
Influence of Endurance Time Test on Microstructure Characteristics of CVD
Coating
Vplyv vytrvalostnej skúšky na mikroštruktúrne charakteristiky CVD povlaku
doc. Ing. Marta Kianicová, PhD., Ing. Ján Kafrík, Ing. Jaroslav Trník, Ing. Dana Bakošová PhD., Faculty of
Industrial Technologies, University of Alexander Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia,
Ing. Ondřej Dvořáček, PBS Velká Bíteš, a.s., Vlkovská 279, 595 12 Velká Bíteš, Czech Republic
The main aim of the experimental work is closely connected with the investigation of the effect of endurance time
test on microstructure characteristics of the CVD coating which was deposited as a protective coating on turbine
blades in the aero engine TJ 100. The experimental part includes endurance time test of the blades which were
exposed to thermo-mechanical fatigue. After the mentioned test, the surface and slices of blades were investigated
and analyzed in the order to find the fatigue cracks and damage and it was observed by REM (scanning electron
microscopy) and energy-dispersion system microanalysis (EDS). One surface crack and two fatigue cracks were
found out on the investigated blades and all these cracks were stopped by layer of protective coating and they was
not allowed to be distributed into the substrate. From the aspect of the thermo-mechanical fatigue which was
simulated by help of the endurance time test, it can be concluded that the protective coating is not degraded
markedly and from the practical aspect it can be used for determined lifetime and conditions of exploitation.
Hlavným cieľom experimentálnej práce bolo zistiť vplyv vytrvalostnej skúšky na mikroštruktúrne charakteristiky
CVD povlaku, ktorý bol aplikovaný ako ochranný povlak na turbínových lopatkách v leteckom motore TJ 100,
vyrábaným PBS Velká Bíteš, a.s. v Českej republike. V článku sú stručne charakterizované základné poznatky
o superzliatinách a ich ochranných povlakoch, ako materiáloch vyvinutých pre prostredie vysokých teplôt
a agresívnych oxidačno-koróznych činiteľov; degradačných módoch konštrukčných materiálov a lopatkách
leteckých motorov. Článok sa zaoberá mikroštruktúrnymi zmenami, ktorým sú vystavené turbínové lopatky,
podrobené vytrvalostnej skúške, ktorá odpovedá letovým prevádzkovým režimom a svojimi znakmi pôsobeniu
termomechanickej únavy. Po skončení skúšky bol analyzovaný povrch a rezy lopatiek vo vyznačených miestach
nábežných a odtokových hrán na prítomnosť únavových trhlín a poškodení pomocou rastrovacej elektrónovej
mikroskopie - REM. Energo-disperzná mikroanalýza – EDS- poskytla informácie o chemických a fázových zmenách
v povlaku a lopatkách po vytrvalostnej skúške. Na skúmaných lopatkách bola objavená iba jedna povrchová trhlina
a dve trhliny únavového charakteru, ktoré boli zabrzdené vnútornou podvrstvou ochranného povlaku a neprenikli
ďalej do substrátu. Lopatky nevykazovali výraznejšie poškodenie. 50 hodinový vytrvalostný test so striedaním
tepelných a napäťových charakteristík zaťaženia turbínových lopatiek ukázal, že CVD povlak zabezpečuje ochrannú
funkciu pred agresívnym pôsobením horúcich plynov a zvyšuje tým životnosť substrátu zo superzliatiny IN 713 LC.
Many industrial machines and their parts are used in
very aggressive environments, such as high
temperatures, increased temperature gradients, high
pressures or stresses on individual parts. Construction
materials are often exposed to oxidizing and corroding
atmosphere too and it causes their erosion and damage
and the component loses functional and usage
properties. Aircraft turbine engines belong among these
components. In present, they are developed with accent
to improve to the flying safety. During combustion
process engine parts are exposed to cyclic mechanical
strain and thermal strain too. This leads to initiation of
cracks and crack growth in material. Thermomechanical fatigue (TMF) is a degradation mode, which
78
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Povrchová úprava
Surface Treatment
involves current existence of both thermal and
mechanical strain (1). This damage is characterized as
long-time creation and crack propagation because there
is an action of external mechanical and thermal strains
as well as residual stresses from different thermal
expansion between substrate and coating (1).
Microstructure analysis of turbine blades
after endurance test
After endurance time test, turbine stator and rotor
turbine blades were analyzed to find fatigue cracks and
other damage. Samples, cut from turbine blades, were
analysed by scanning electron microscopy (SEM). One
crack (fig. 2) was observed on leading edge of stator.
Description of test experiment
Engine TJ 100 (fig. 1) is small turbine engine designed
for sports ultralight planes, gliders equipped with
additional engine and other pilotless jets. Advantages of
engine are compact design; perfect weight/thrust ratio;
low fuel consumption and low exhaust fumes
production. Turbine blades and other parts of engine TJ
100 are created from nickel-basesuperalloys Inconel 713
LC. The protective diffusion Al coating was deposited
on turbine blades.
Fig. 2 Surface crack on leading edge of stator blades
Obr. 2 Trhlina na povrchu nábežnej hrany statorovej lopatky
Microstructure analysis of stator blade
The top sublayer and bottom sublayer of coating (fig. 3)
with average thickness 34 µm was observed on the
leading edge of stator blade in cross section
Fig. 1 Trubine engine TJ 100
Obr. 1 Turbínový motor TJ 100
50-hour’s time test is composed of 50 cycles by 66
minute engine running. One cycle (tab. 1) was repeated
50 times and total time of test took 55 hours.
Tab. 1 One cycle of endurance time test
Tab. 1 Jeden cyklus vytrvalostnej skúšky
1.
Holding
time
1 min
2.
10 min
3.
5 min
4.
1 min
5.
5 min
6.
1 min
7.
30 min
8.
1 min
9.
Overall
10 min
10.
11.
2 min
12 min
Pt
Operating condition
Engine start and idle
Maximum take-off mode (100%
thrust)
Maximum permanent mode (97%
of revolutions)
Idle run (50% of revolutions)
Maximum soaring mode (100%
thrust)
Idle run
Maximum permanent mode (97%
of revolutions)
Idle run
Fig. 3 Microstructure in the cross section of stator blade
Obr. 3 Mikroštruktúra v reze statorovej lopatky
One micro crack (fig. 4) was found out on the leading
edge of stator blade too. We supposed that crack was
created by different coefficients of thermal expansion.
This crack was stopped by diffusion sublayer of coating
which did not allow crack propagating.
6 cycles of acceleration
and deceleration from idle to
maximum take off and back
Idle + engine stop +cooling
break
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Povrchová úprava
Surface Treatment
Hutnic ké listy č.7/2012, roč. LXV
ISSN 0018-8069
Conclusions
Stator and rotor turbine blades were tested by 50-hours
endurance time test under the thermo-mechanical
loading. After the mentioned test, the surface and crosssections of blades were investigated and analysed to
find the fatigue cracks and other damages. Aluminide
protective coating was deposited by CVD technology
and played roll of barrier between base material of
turbine blades and aggressive environment in engine
turbine. Detailed observation of stator and rotor blades
showed that turbine blades withstand endurance test
without significant damages.
Fig. 4 Crack on leading edge of stator blade
Obr. 4 Trhlina na nábežnej hrane statorovej lopatky
Two types of cracks were found out on stator blade. The
first surface crack was on leading edge (fig. 2), second
crack on leading edge too and it was created by different
coefficients of thermal expansion.
Microstructure analysis of rotor blades
The visible phase changes (fig. 5) were observed on
leading edge.
These cracks were stopped by inner sublayer of
protective coating and did not permit crack propagating
into the substrate.
Rotor blades were without cracks and other damages.
From the aspect of the thermo-mechanical fatigue which
was simulated by help of the endurance time test, it can
be concluded that the protective coating is not degraded
markedly and from the practical aspect it can be used
for determined lifetime and conditions of exploitation.
Literature
[1] BOSE, S. High temperature Coatings. Elsevier Science &
Technology Books, 2007.232 p. ISBN 0750682523
[2] ASM Handbook: Failure Analysis and Prevention, 2002. Vol. 11,
ISBN: 0- 87170-704-7
[3] TAMARIN, Y. Protective Coatings for Turbine Blades. Ohio:
ASM International, 2002. 217 p. ISBN 0-87170-759-4
Fig. 5 Comparison of damage of leading edges
Obr. 5 Porovnanie poškodenia nábežných hrán
[4] STEKOVIC, S. Low Cycle Fatiuge and Thermo-Mechanical
Fatigue of Uncoated and Coated Nickel-Base Superalloys.
Doctoral thesis. Department of Management and Engineering
Linkoping University, Sweden. 2007. 57 p. ISSN 0345-7524
These phase changes indicate process of spalling.
Trailing edge was without significant damages. Average
thickness of coating on trailing edge was measured and
it was 59.5 μm (fig. 6).
[5] HUANG, Z.W., WANG, Z.G., ZHU, S.J., JUAN, F.H., WANG,
F.G. Thermomechanical fatigue behavior and life prediction of
a cast nickel-based superalloy. Materials Science and Engineering
A. 2006, vol. 432,no. 1-2, pp. 308–316. ISSN 0921-5093
Review: prof. Ing. Františka Pešlová, PhD.
doc. Ing. Ján Bezecný, CSc.
Fig. 6 Average thickness of coating
Obr. 6 Priemerná hrúbka povlaku
80
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Zkušebnictví, měřictví, laboratorní metody
Testing, Measurement, Laboratory Methods
zkušebnictví, měřictví,
laboratorní metody
_____________________________________________________________________________________________
Determination of Radial Stiffness of Tire from Experiments on the Static Test
Device Called Static Adhesor
Stanovení radiální tuhosti pneumatiky z experimentů na statickém zkušebním
zařízení nazývaném statický adhezor
doc. Ing. Jan Krmela, PhD., Ing. Michal Pastorek, University of Alexander Dubček in Trenčín, Faculty of
Industrial Technologies, I. Krasku 491/30, 020 01 Púchov, Slovakia
The paper deals with static experiments on special test machine for tires – static adhesor. The radial stiffness of
tires is possible to be obtained on the basis of the radial deformation characteristics from experiments on statical
adhesor. The radial stiffness is different for the same tire when the tire inflation pressures are different. The
modified formula presented by the author Krmela was used for calculation of the values of radial stiffness from
experimental data. In this paper, the results of experiments on static adhesor for a tire casing 215/40 R17 are
presented. The tire was loaded from zero to about 680 kg. Values of the radial tire stiffnes were obtained by
measuring. Simultaneously the contact areas between the tire casing and the surface plate were evaluated. The
contact have been obtained using the "ink print", and also by application of pressure indicating films. From the
prints on the pressure indicating films, the distribution of the contact pressure in the contact area can be obtained
by analysis. Knowledge on contact areas and contact pressures is necessary for the verification analyses including
comparison of experimental results to computational modeling relating to tires.
Článek se zabývá statickými experimenty na speciálním statickém zkušebním zařízení nazývaném statický adhezor.
Experimenty lze získat radiální deformační charakteristiku. Z této charakteristiky lze výpočtem získat radiální
tuhost, která je důležitým parametrem vstupujícím do výpočtů celých automobilů tím, že tento parametr nahrazuje
tuhostně celou pneumatiku. Pro stejnou pneumatiku ale pro různé hodnoty tlaku huštění je radiální tuhost rozdílná.
Autorem Krmela byl normou uvedený výpočtový vztah upraven modifikovaným výpočtovým vztahem, který bere
v úvahu reálnější provozní podmínky zatěžování pneumatik. V tomto článku jsou uvedeny výsledky z experimentů na
statickém adhezoru vybrané pneumatiky s pláštěm 215/40 R17, která byla nahuštěna na tlak 2,5 bar. Pneumatika
byla zatěžována od nuly po cca 680 kg, což odpovídá 125% maximálního zatížení. Měřením byla získána hodnota
radiální tuhostní pneumatiky, která pro konkrétní tlak huštění činí cca. 260 N/mm. Zároveň byly hodnoceny styčné
plochy ve styku pláště s podložkou. Styčné plochy byly získány metodou “otisk inkoustem” (alternativně lze použít
průklepový papír) a také s aplikací tlakocitlivých fólií. Z otisků na tlakocitlivých fólií lze analýzou získat rozložení
kontaktního tlaku v dotykové ploše. Na statickém adhezoru lze pneumatiky s rozměrem pláště od R13 do R18 a max.
šířkou pláště 245 mm zatěžovat až do hodnoty 1,2 t. Znalosti o kontaktní ploše a distribuci kontaktního tlaku v dotykové
ploše jsou potřebné pro verifikační analýzy mezi výsledky z výpočtového modelování a experimentálními údaji.
Experimental data from tire deformation characteristics are
needed as the verification criteria for computational
modeling of tire casings. The basic characteristic for the
initial comparative analysis is the radial deformation
characteristic of the tire and it can be obtained from static
experiments on the test device called static adhesor.
the casing. The vertical force can be understood as the
pressure of the inflated tire against a rigid surface which is
perpendicular to the direction of loading and the vertical
deformation of the casing is generated from
the loading between the wheel rim and the surface in place
of the tire and surface contact.
Radial deformation characteristic is the dependence
between the vertical force and the vertical deformation of
On the basis of the name of the test device which is called
static adhesor, the slip characteristics of the tire can also be
81
Zkušebnictví, měřictví, laboratorní metody
Testing, Measurement, Laboratory Methods
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
measured because it is necessary to point out that the slip
characteristic is also one of the important characteristics of
the tires.
The radial deformation characteristic can be used for
calculation of the radial stiffness which is another
important parameter for the precise calculation relating to
the of cars as the whole because the stiffness parameter
replaces the whole tire.
Experiment
The standard ČSN 63 1511 [1] defines the radial
stiffness from the radial deformation characteristic by
using a computational relationship which is determined
by points corresponding to 75% and 125% of load
inflation index (LI index).
Fig. 1 The tire in the static adhesor prepared for measurement
Obr. 1 Pneumatika na statickém adhezoru připravená k měření
Based on long-term experimental testing, the author
Krmela adjusted the given computational relationship
used in standards and it was adjusted by modified
computational relation [2]. This modified equation (1)
takes into account more real operating conditions during
the loading of tires.
S
F(0.75 x125% load ) - F(0.75 x 75% load )
x (0.75 x125% load ) - x (0.75 x 75% load )
[N/mm]
where S [N/mm] – radial stiffness,
F(0.75x125%load) [N] – vertical force for 125%
0.75xmaximum load,
F(0.75x75%load) [N] – vertical force for 75%
0.75xmaximum load,
X(0.75x125%load) [mm] – radial deformation for 125%
0.75xmaximum load (F(0.75x125%load)),
X(0.75x75%load) [mm] – radial deformation for 75%
0.75xmaximum load (F(0.75x75%load)).
(1)
of
of
of
of
In this paper, there are the results of experiments of
a selected tire casing 215/40 R17 where the static
adhesor was used as the testing device. The casing has a
maximum load capacity index which is specified for
maximum load at approx. 550 kg. Maximum
permissible inflation pressure is 3.4 bars. Measurements
were made at the inflation pressure of 2.5 bar (fig. 1),
which is determined by the usage of the given tire on
a specific vehicle. The pressure corresponds to about
75% of the maximum inflation pressure.
The tire was loaded from zero to about 680 kg and it
corresponds to 125% of LI. According to standards, the
load speed of tire during experiments must be
approximately between 0.8 and 2.5 mm/s [1].
Deformation of the tire casing in contact with the surface
plate was recorded during the experiment and is shown in
fig. 2. All of the three measurements were performed at
different locations around the perimeter of the tire.
Fig. 2 Deformation of the casing for individual loading steps
Obr. 2 Deformace pláště pro jednotlivé zátěžové kroky
The results from the measurements are:
 the radial deformational characteristic,
 radial stiffness,
 analysis of contact area in the site of contact between
the tire casing and the surface plate,
 distribution of the contact pressure in the contact area.
Results and discussion
A radial deformation characteristic for the pressure
2.5 bars is shown in fig. 3. At the tire load of 100% of
LI, the deformation was 20.0 mm during contact with
the surface plate. Under the load 125% of LI
the deformation was 25.1 mm. Based on data provided
by the tire manufacturer, the deformation at 100% of LI
should be about 18 mm, but this value is set for the
maximum inflation pressure of the casing.
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ISSN 0018-8069
Zkušebnictví, měřictví, laboratorní metody
Testing, Measurement, Laboratory Methods
Fig. 3 Radial deformation characteristic
Obr. 3 Radiální deformační charakteristika
On the basis of the equation (1) the radial stiffness of
the individual measurements was determined. Average
value from all measurements of the radial stiffness was
258 N/mm. This value is applied for the loading tires.
Stiffness values obtained on the basis of unloading of
the tire casing were approx. 300-310 N/mm.
It is fact that with the increasing inflation pressure, the
radial stiffness increases.
Fig. 4 The print of the contact areas for two loading states of a tire
Obr. 4 Otisk styčné plochy pro dva zatěžující stavy pneumatiky
Simultaneously the contact areas referring to contact of
the casing with the surface plate were evaluated. The
results from this evaluation give the information about
the size of the contact area as well as about the
distribution of the contact pressure in the contact area in
relation to usage of special pressure indicating films.
The contact areas obtained by the "ink print" method (or
alternatively by carbon paper) for the selected load
values are shown in fig. 4. Size of the contact area for
545 kg load is 12170 mm2.
Simultaneously, prints were made by using pressure
indicating films FUJI Prescale® (fig. 5). The used type
of film was 28-85 psi (2-6 kg/cm2) Ultra Low Film
LLLW. The film was exposed to loading for 2 minutes
and 30 seconds. Pressure indicating films are strongly
sensitive to moisture. Specific measurements were
carried out at 21 °C and humidity was 31%. From the
print, the analysis of the distribution of the contact
pressure in the contact patch can be provided.
Fig. 5 The print of the contact area for 100% of LI (for 545 kg)
acquired from pressure indicating films
Obr. 5 Otisk styčné plochy pro 100% LI (pro 545 kg) získaný
tlakocitlivou fólií
Conclusions
On the static adhesor, it is possible to load the tires up to
the value of approximately 1.2 tons.
Nowadays, on the static adhesor, it is possible to test the
tires with the tire radius from R13 to R18 and with the
maximum width of tire-carcass c. 235-245 mm.
83
Zkušebnictví, měřictví, laboratorní metody
Testing, Measurement, Laboratory Methods
Knowledge about contact areas and contact pressures is
necessary for the verification analyses relating to the
experiments and computation modeling of the tires.
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
[2]
KRMELA, J.,
BENEŠ, L.,
KRMELOVÁ, V.
Statical
Experiments of Tire as Complex Long-Fibre Composite for Obtaining
Material Parameters and deformation Characteristics. Material
engineering (Materiálové inžinierstvo). Žilina, Slovakia: 2012, 19, (3),
p. 124-135. ISSN (print): 1335-0803, ISSN (online) 1338-6174
Literature
Review: prof. Dr. Ing. Milan Sága
prof. Ing. Ján Vavro, PhD.
[1] ČSN 63 1511 – Standard: Testing of Tyres. Determination of
Static Radial Stiffness and Static Tyre Radius, 1983 (in Czech)
_____________________________________________________________________________________________
Vážení kolegovia,
dovoľujeme si Vás pozvať na 5. Medzinárodnú konferenciu Odpady – Druhotné suroviny 5,
ktorá sa uskutoční v dňoch 4. – 7. júna 2013 v Liptovskom Jáne, Slovensko.
Rokovací jazyk: slovenčina, čeština, angličtina - simultánny preklad je zabezpečený.
Všetky ďalší potrebné informácie a dôležité termíny nájdete na
www.tuke.sk/waste.
Tešíme sa na Vašu účasť na konferencii.
Organizačný výbor
Dear colleagues,
It is our great honour and pleasure to invite you to attend the 5th International Conference Waste
– Secondary
Raw Materials 5, which will take place since the 4th to 7th June 2013 in
Liptovský Ján, Slovakia.
Conference language: Slovak, Czech, English - simultaneous translation is prepared.
All next information and milestones are available on
www.tuke.sk/waste.
We look forward to your participation at the conference.
Organizing committee
84
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ISSN 0018-8069
Zkušebnictví, měřictví, laboratorní metody
Testing, Measurement, Laboratory Methods
Simulation of Brittle Rupture of Thin-walled Steel Components
Modelovanie krehkého porušovania tenkostenných oceľových súčiastok
doc. RNDr. Ján Bezecný, CSc., Ing. Ján Mičic, Faculty of Industrial Technologies, University of Alexander
Dubček in Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia
This paper contains several cases of formation of brittle intergranular cleavage fracture relating to thin-walled
components. The occurrence of this brittle intergranular cleavage fracture was connected with their long-lasting inservice loading of various types but in all cases, the bending stress is a dominant stress. Components were made of steels
with higher content of carbon and the properties of steels were modified by heat treatment. In all cases, the content of
residual austenite, the increase of which was above 10% was observed. Moreover, the change of the size of the original
austenite grains was also discovered – the grains were larger. We decided to make up the simple testing device and
specify the testing procedures for simulation of real in-service conditions of loading for thin metal plates because we have
not found any evidence about mechanism relating to occurrence of brittle intergranular fracture in material which is
commonly tested from aspect of and this material is ruptured on the basis of the during the common tests of transgranular
ductile fracture. The proposed tests should lead to intergranular fracture of samples, which exhibit transgranular ductile
fracture at the fast impact fracture. Obtained results could be used for explanation of occurrence of this phenomenon.
Príspevok obsahuje viaceré príklady vzniku krehkého interkryštalického štiepneho lomu u tenkostenných súčiastok,
ktorý vzniká pri ich dlhodobom prevádzkovom namáhaní rôzneho typu. Vo všetkých prípadoch prevládala ohybová
zložka napätia. Súčiastky boli vyrobené z ocelí s vyšším obsahom uhlíka a tepelne spracované zušľachtením. Vo
všetkých prípadoch bol nameraný zvýšený obsah zvyškového austenitu nad 10 % a nárast veľkosti pôvodných
austenitických zŕn. Nakoľko nebol doteraz v nám dostupnej literatúre popísaný a vysvetlený mechanizmus vzniku
krehkého interkryštalického lomu v materiáli, ktorý sa pri bežných lomových skúškach porušuje tvárne
transkryštalicky jamkovo, navrhli sme jednoduché skúšobné zariadenie a postup skúšok, ktorými by sme simulovali
reálne podmienky namáhania tenkých plechov v prevádzke. Vzorky z plechov sme zakalili z kaliacich teplôt 1000
a 1030 °C s výdržami na teplote 5 a 10 min. a popustili pri teplote 140 °C / 2 hod. Dosiahnuté obsahy zvyškového
austenitu sa pohybovali v rozmedzí 10,4 – 21,0 %. Navrhnuté skúšky by mali viesť k interkryštalickému štiepnemu
porušeniu vzoriek, ktoré pri rýchlom rázovom lome vykazujú transkryštalický jamkový lom. Získané výsledky by mali
pomôcť vysvetliť vznik uvedeného javu.
After a few hours of exploitation (the attention was not
paid to time), the results referring to real cases of
untypical rupture of thin-walled components could be
described in some our papers and studies. In the most
cases, the components were made of thin plate metal but
some of the cylindrical thin-walled components were
also included there. The in-service cracks were
propagated in an intergranular way although the final
fractures as well as laboratory fractures exhibited the
transgranular ductile mechanism and it was quite
untypical feature (fig. 1).
a)
b)
Fig. 1 Fracture areasof the broken collet: a) in-service fracture,
b) area of final fracture
Obr. 1 Lomové plochy prasknutej klieštiny: a) prevádzkový lom,
b) dolomenie
We conclude that it is closely connected with the heat
treatment, according to the fact that the occurrence of
the brittle fracture was always related to increased or
high content of residual austenite and increased size of
the original austenitic grains.
Practical examples of crashed components
Ribs of grape picker
The rib of grape picker was the first part for which the
mentioned rupture was observed and it can be seen in
the fig. 2. The rib is as a part of the grape picker is made
of a material DOMEX 044 which is alloyed by element
B. It consists of two thin sheets, the joint of which was
done by pressing-in.
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ISSN 0018-8069
After the discovery of the occurrence of cracks in the
components, joint welding was proposed to be used for
joining. After that, the spot-weld for given components
was proposed to be used because the cracks at the
exploitation or after the long periods of storage, were
still detected. After the steps which minimized internal
stresses in the material, there was not any occurrence of
crack. In relation to these components, the modification
of the regime of the heat treatment was also proposed on
the basis of the evaluation of the microstructure and
fracture. Ribs with crack had significantly
heterogeneous, coarse, acicular structure consisting of
tempered martensite or bainite. Austenite grain size was
evaluated by degree 5 or even 6. The microstructure
relating to suitable ribs with modified regime of heat
treatment was fine-grained, homogeneous and it
consisted of lower-tempered martensite and austenite
grain had size 10.
Pressure plate, fig. 3 has a thickness of 1 mm as ell as
inner hole and outer undercut for security pin. This
component has been hardened and tempered to the
hardness of 61-64 HRC.
The analysis of the accident led to discovery that the
plate was not board installed horizontally. Due to
dimensional inaccuracies of assembly, it was installed
under a slight unspecified inclination. Component was
exposed not only to stress of the pressure, as determined
by the designer, but also to bend. Component has been
broken through the whole diameter.
Microstructure had the appearance of fine, acicular
lower-tempered martensite and residual austenite.
Micromorphology of fracture surface was mainly
composed of IGC fracture. According to these findings,
laboratory fractures were prepared on the basis of the
impact bend fracture relating to samples without notch.
In the case of these samples, we band observed with only
IGC facets in the subsurface areas (areas of the pressure
stress) and it was along the all width of the sample, fig.
2. The mechanism of fracture suddenly changed towards
the core and it was TGD up to the opposite surface.
Radiographic method was used for determination of
residual austenite which was 13.0 ± 1.5 %.
Micromorphology of the fracture surfaces for the
original cracks was created by intergranular cleavage
(IGC) fracture. The laboratory fractures prepared on the
basis of breakage of defective ribs showed the presence
of coarse IGC facets in subsurface areas and it was in
those sites where there was the occurrence of the
pressure stress during breaking. The rest part of the
fracture was composed of a mixed transgranular
quasicleavage (TGQ) and transgranular ductile (TGD)
fracture. The ribs with the modified regime of heattreatment showed only TGD fracture. The content of
residual austenite was measured by X-ray diffraction
method for the planes (200) of austenite and martensite.
The content for samples with cracks was 9.94% and
content for samples without cracks was only 3.25 and
4.97%. In this case the cracks occurred on the basis of the
stress effect which was caused by squeezing or welding
and in the case of welding the deformation was caused by
thermal cycle of welding. It can be assumed that the
cracks occurred later or they did not occur in the same
time when the installation or welding was provided.
Fig. 2 Rupture rib
Obr. 2 Prasknuté rebro
Collet
Another case of the above-mentioned untypical cracking
is connected with collets of a dental drill. Collet is made
of material 1.4034 which is characterized as chromium
martensitic stainless steel. Collet has the shape of
a hollow cylinder with a wall thickness of 0.4475 mm
where two undercut by a 2 ° chamfer of so called legs,
fig. 4. Component has been hardened and tempered to
a hardness of 640 HV but high toughness was preserved.
Fig. 4 Collet and draw of collet with specified sites of fracture and
crack
Obr. 4 Klieština a nákres klieštiny s naznačenými miestami lomu
a trhliny
Fig. 3 Damaged pressure plate
Obr. 3 Havarovaná tlaková doska
Pressure plate
The collet rupture has occurred in after short in-service
time. After removal of collet from casing, it was found
that one of so-called legs was broken off. The microscopic
observation revealed intergranular crack propagating from
outside of the collet in relation to the leg.
The pressure plate was made of a material 16270. The
material is characterized as a steel alloy with a high
trough-hardenability, high hardness and high toughness
in the quenched and tempered state. Tempered
susceptibility to brittle in relation to tempered state of
material is not known.
The microstructure component is formed by lowertempered martensite and fine globular carbides.
Micromorphology of in-service fracture was mainly IGC,
fig. 1a). The laboratory fractures were prepared for the
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Zkušebnictví, měřictví, laboratorní metody
Testing, Measurement, Laboratory Methods
rest of collet and the occurrence of low-energetic TGD
fracture was observed, fig. 1b) but IGC facets were not
revealed. Using the finite element analysis (FEM) we
were able to confirm that the collet is loaded by bending
after inserting borer. The comparison of the location of
the fracture and crack by help of the FEM model
confirmed that the fracture and crack are located in areas
with the greatest stresses during exploitation, fig. 5.
bending stress or bending strength was done according
to the formula:
RP0   o 
M MAX
6.F .l

W
4.b.h 2
(1)
where: δ0 - bending stress, Mmax – the highest moment
of bending, W - cross-section modulus, F - acting force,
l – support span, b - dimension of rectangular crosssection, perpendicular to the direction of load (width), h
- dimension of rectangular cross-section parallel to the
load (thickness).
The bending modulus was calculated from the
relationship:
E
F .l 3
48.I . y
(2)
where: I - is the moment of inertia of the loaded crosssection, l - support span, y – deflection of sample.
Fig. 5 FEM model of collet under stress conditions
Obr. 5 MKP model klieštiny s napäťovými stavmi
The sample is bent gradually in three steps to obtain the
desired stress. In the first step, the sample is bent to
obtain the stress 80% of the yield stress, in a second
step, it is bent to gain stress 90% of the yield stress and
the third step it is bent to the value of the yield stress.
Each one step took 24 or 48 hours. Holding time on the
yield stress should ensure sufficient time to initiate
cracks in the sample under constant bending stress. The
test can be successful only if there is the formation of
crack of IGC in the area of bend relating to the thin
plate. The main objective is to assess the stress
conditions leading to fracture initiation of IGC fracture.
Draft test equipment
The proposed device or equipment, fig. 6, 7 is designed
for static bending test. Static bending test is mainly used
for testing brittle materials. This test can not be applied
for tough materials due to the fact that there is not any
rupture of the samples. Therefore this mentioned test is
mainly applied as technology test and test for finished
parts. Due to the specific conditions relating to
occurrence of the brittle rupture described above, the
tested samples were quenched under in relation to
transgranular ductile rupture and subsequently, they
were heat-treated from higher temperature to the
temperature at which we assume the occurrence of
intergranular facets. The role of testing in this case is to
bring the brittle intergranular rupture for thin-walled
quenched steel components.
Literature
[1] BEZECNÝ, J. Príspevok k problematike krehnutia materiálu
16 270 po kalení a popustení, In: Přínos metalografie pro řešení
výrobních problémů, ČVUT Praha, Mar. Lázně, 1996
[2] BEZECNÝ, J. Metalografická analýza atypického praskania
zvarencov tenkých plechov, In: Přínos metalografie pro řešení
výrobních problémů, Lázně Libverda, 2005
[3] MIČIC, J. Krehnutie tenkostenných zušlachtených ocelí vplyvom
ohybového namáhania, Projekt dizertačnej práce, FPT Púchov,
2010/2011
[4] BEZECNÝ, J. Vznik trhlín a lomov pri tepelnom spracovaní
ocelí, Trenčianska univerzita A. Dubčeka v Trenčíne, ISBN:
978-80-8075-202-6, 2007
Fig. 6 Design of the model test
equipment in
SolidWorks
Obr. 6 Návrh modelu
skúšobného zariadenia
v SolidWorks
[5] MIČIC, J., BEZECNÝ, J., PALIESEK, J. Localization of action
area of maximal stresses in collet during her exploitation, In
Machine Modeling and Simulations 2011. Trenčín : TnUAD,
2011. ISBN 978-80-8075-494-5. p.99-104
Fig. 7 Equipment designed for
static bending test
Obr. 7 Zostrojené zariadenie na
statickú skúšku ohybom
[6] MIČIC, J. Praktické príklady netypického praskania
tenkostenných oceľových súčiastok pri exploatácii, In Letná
škola únavy materiálov, Oščadnica, Žilinská univerzita, 2010.
ISBN 978-80-554-0235-2. p.190-193
[7] MIČIC, J., BEZECNÝ, J. Modelling of the Bending Stress for
Thin-walled Component, In Hutnické listy. ISSN 0018-8069.
Roč. LXIV, č.7(2011), p.125-128
The test procedure consists of the gradual loading of thin
steel plate with dimensions 100 x 20 x 2 mm up to the
yield stress. Achieving the required stresses up to yield
stress is obtained by bending of the thin plate to a pecified
deflection. Deflection of the sample is calculated from the
relationship for a three-point symmetrical bending and
modulus of elasticity for bending. Calculation of the
Review: prof. Ing. Františka Pešlová, PhD.
prof. Ing. Ján Vavro, PhD.
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Zkušebnictví, měřictví, laboratorní metody
Testing, Measurement, Laboratory Methods
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Modification of Equipment EDYSCAN for Accurate Measurement
Modifikácia zariadenia EDDYSCAN na presné meranie
doc. RNDr. Ján Bezecný, CSc., Faculty of Industrial Technologies, University of Alexander Dubček in Trenčín,
I. Krasku 491/30, 020 01 Púchov, Slovakia, Ing. Annamária Petráňová, Welding Research Institute - Industrial
Institute SR, Račianská 3, 832 59 Bratislava 3, Slovakia
The given paper gives information on the experience which was gained by control and monitoring of radiation tubes
by EDDYSCAN equipment in refineries and chemical industries. The paper describes the evaluation of centrifugally
cast tubes of reforming furnaces by help of climbing semi-automatic diagnostic crawler tractor which was
developed and constructed by Welding Research Industrial Institute of Slovakia in Bratislava. Developed semiautomatic EDDYSCAN works on the principle of Eddy current and allows inspectors to control the construction of
the tubes as well as any cylindrical bodies. The diameter change, internal and external defects are able to be
recorded by help of developed software EDDY which is commonly utilized together with EDDYSCAN device
consisting of the eight measuring probes (with 4 channels “S, I, O, W) which are uniformly placed on the
circumference of the tubes. On the basis of utilized device together with the given software, we have found out that
the measured signals relating to ‘S’ channel shows the sensitivity especially to changes of material properties.
Predmetom príspevku sú skúsenosti nadobudnuté kontrolou a sledovaním radiačných rúr, zariadením EDDYSCAN,
v rafinérií a v chemickom priemysle. Vyvinutý a skonštruovaný poloautomat EDDYSCAN, firmou VÚZ- PI SR,
pracuje na princípe vírivých prúdov a umožňuje svojím konštrukčným riešením kontrolovať rúry a valcové telesá.
Zariadenie EDDYSCAN obsahuje 8 univerzálnych meracích sond (so 4 kanálmi ‘S,I,O,W’), ktoré sú rozložené
rovnomerne po obvode rúr. Spolu s vyvinutými softvérom EDDY umožňuje zaznamenať zmenu priemeru, vonkajšie
a vnútorné defekty. V príspevku sú popísané viaceré skúšky, uskutočnené počas vývoja automatu, zamerané na
citlivosť sond a presnosti merania zariadenia, zhodu meraní pri pohybe zariadenia smerom hore a smerom dole,
zmeny indikácií kanálov ‘I a W’ (vnútorné chyby, zmena hrúbky steny) vplyvom vnútorných defektov a zmeny
vlastností povrchu, vyhodnotenie zmien priemeru rúr a zmeny výsledkov merania priemeru rúr kanálom ’DIA’
vplyvom nánosov a opalov. Porovnanie záznamov z meraní smerom hore a smerom dole sme poskytli dôkaz vysokej
zhody meraní v oboch smeroch na všetkých kanáloch, čo dokazuje, že lokalizácia a veľkosť nameraných odchýlok je
reálna. Indikácia odchýlky kanálom ‘I’ a ‘W’ je korektná iba vtedy, keď signál týchto kanálov je výrazný, a naopak
signál ‘S’ a‘O’ je takmer žiadny, alebo len slabý. Vývojom zariadenia a softvéru sme zistili, že namerané signály
z kanálu ‘S’ sú citlivé predovšetkým na zmeny materiálových vlastností a nie, ako sa predpokladalo, na zmeny
priemeru rúr.
Equipment (automatic crawler) for NDT
examination of CCT
The problem of reliability and safety is very important
in plants of refineries and chemical industry. The inservice equipment and devices as well as their
individual parts (Centrifugally Cast Tubes - CCT) lose
their utility properties in these mentioned branches
meanwhile over the world – they are subject to aging
therefore the continuous control of them is very
important and if it is needed they have to be replaced
after some time. Recently, enormous effort has been
made to develop some diagnostic methods and systems
which would be utilized for inspection and control of
tubes during their operation as well as during their
production and reparation. EDDYSCAN equipment
operating on the principle of eddy current method
represents a very perspective alternative for the
identification of size changes as well as inner and outer
defects of CCT.
The crawler (fig. 1) consists of three basic parts: front
part, rear part and head. The head is the platform for
eddy current probes which are used for the identification
and making records of defects.
Fig. 1 Diagnostic EDDYSCAN equipment
Obr. 1 Zariadenie EDDYSCAN
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Zkušebnictví, měřictví, laboratorní metody
Testing, Measurement, Laboratory Methods
Measurement
downwards
Sensor
The EDDYSCAN equipment consists of 8 universal
measuring probes which are uniformly distributed on the
circumference of tubes. Each probe has 4 channels (S –
surface properties of tubes, O – identification of surface
defects, surface properties of tube, W – change of wall
thickness, I – identification of inner defects) the signal of
which is recorded by computer in the independent
graphical records of the developed EDDY software. The
capacity transducer (DIA channel) which measures tube
diameter from its metallic surface, is integrated in
probes, i.e. the effect of non-metallic deposits on the
diameter change is eliminated. The automatic
equipment allows measurements in two directions
during movement which is upwards and downwards.
The travel speed represents max. 25 cm/min.
conformity
test
upwards
and
To evaluate the measurement conformity in both
directions (upwards and downwards) the measurements
recorded by EDDY software were carried out. The
measured deviation relating to control upwards
through ‘S, O, W, I’ channels is real only if it is
proved on the same area and the same fact is also
valid during the control of the tube downwards. The
measurement upwards is shown in the fig. 2a and the
measurement downwards is illustrated in fig. 2b. The
comparison of records from measurements upwards and
downwards (fig. 2a and fig. 2b) provides the proof of
high conformity of measurements upwards and
downwards for all channels. The conformity of
measurements recorded upwards/ downwards proves that
the locality and size of measured deviations are real.
Results of experiments
In order to improve the measurement method (by eddy
currents),
the
sensitivity
and
precision
of
(EDDYSCAN) measuring equipment, the automatic
equipment was tested on operating CCT in reforming
ammonia and hydrogen furnace. During testing of
EDDYSCAN equipment, several sensitivity tests of
probes and measurement precision of the equipment
were carried out, namely:
 conformity measurement test upwards and downwards,
 identification of inner defects (I signal) and wall
thickness (W signal),
 identification of diameter change (S signal),
 test of diameter change of tubes due to the effect of
deposits and scorches.
The measurement in operating conditions stemmed from
the assumptions gained from laboratory measurements –
calibrations described in the paper [1].
Fig. 3 Example of affection of ‘I’ and ‘W’ signals by surface
inhomogeneities (probably microstructure change) detected
by ‘O’ channel from measurement in hydrogen furnace
Obr. 3 Ovplyvnenie „I“ a „W“ signálu povrchovými detekovanými
kanálom „O“ z merania v peci na výrobu vodíka
Identification of inner defects (I signal) and wall
thickness (W signal)
The records from ‘I’ and ‘W’ channels are used to
evaluate the inner defects and the wall thickness. Both
signals are affected by tube surface properties. The
surface of tube can exhibit different magnetic and
conduction properties as the remaining inner material of
tube. These differences of magnetic and conduction
properties can be induced by surface failures as well as
different microstructure which can be manifested on the
surface by coarsening of carbidic networks in
comparison to the remaining material thickness. The
deviation indication by ‘I’ and ‘W’ channels is correct
only in that case when the signal of these channels is
significant and on the contrary, the ‘S’ and ‘O’ signals
are almost none or only weak, as it is shown in fig. 3.
Fig. 2a Rapid diameter change identified in tube during
measurement upwards in the hydrogen furnace
Obr. 2a Meranie smerom nahor v peci na výrobu vodíka
Identification of diameter change (S signal)
If the deviation is indicated in the same tube height by
several probes simultaneously, it means an inner defect of
material distributed on the tube circumference but it is
improbable in the case of tube initial material, because
the cracks in initial material are oriented in a parallel way
with the tube axis and not transversely. It is known that
25Cr35Ni material fails at 5 – 7 % strain. As the
measurements were carried out in operated tubes, it is
necessary to consider the actual diameter of tube which
can differ from the diameter of newly fabricated tube. An
Fig. 2b Rapid diameter change identified in tube during measurement
downwards in the hydrogen furnace
Obr. 2b Meranie smerom nadol v peci na výrobu vodíka
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example of identification of tube diameter recorded by
‘S’ signal is illustrated in fig. 4. The diameter of tubes is
possible to be evaluated by ‘S’ channel only if the
magnetic properties in the tube are not changed. It is
especially connected with the trouble-free conditions
relating to tubes. With respect to the development of the
method in relation to Welding Research Industrial
Institute, the innovations of the automatic crawler as well
as the innovations of the evaluating software and
measuring probes have taken place. The development of
eddy current method has proved that the measured
deviation of tube diameter by ‘S’ channel was not
induced in some tubes by the change of tube diameter but
by the change of magnetic properties of material in max
thickness 1.5 mm under the tube surface. The curves
relating to the deviation of ‘S’ channel can be used for
mutual differentiation of the diameter change and the
microstructure change. The curves of individual signals
of ‘S’ channel exhibit the wave shape with almost
identical height of wave amplitude and repetition
frequency. This description corresponds to the so-called
noise of detected signal. The standard proof of diameter
increase is the fact that this change occurred in all
signals continuously and not stepwise. The diameter
change was evaluated according to the deviation of the
mean curve (red curve) which with its smooth shape
eliminates both the noise and sudden diameter changes.
It means that the change of diameter is classified by ‘S’
channel if the deviations exhibit a continuous course.
The effect of the change of material magnetic properties
induced by microstructural changes or by the presence of
cracks is recorded by ‘S’ channel stepwise – a stepwise
signal change. For its detection the function of this
channel was preset to microstructural changes of material.
Test of tube diameter change due to the effect of
deposits and scorches
After putting the ‘DIA’ channel into the operation the
measurements for the assessment of the effect of
deposits and scorches were carried out. It has been
found out that the surface roughness, deposits and
combustion products affect the value of measured
deviation of ‘DIA’ diameter. The effect of the abovementioned statement is shown in fig. 5 where a slight
inflation of tube below the first weld was indicated. The
first measurement was performed on the not cleaned
tube (dark blue curve in fig. 5). The second
measurement was carried out on the tube cleaned in the
section at about 2 m from the first weld downwards (red
curve in fig. 5). With simple cleaning of the surface
(manually with abrasive paper) the diameter deviation
decreased by 0.5 %. This grinding did not cause
smoothing of tube surface, only the dust and deposits of
combustion products, which easily were released from
the tube surface in contact with emery paper, were
removed. During testing of the above-mentioned
diameter measurement method we could identify the
diameter change with high sensitivity of 0+0.1 mm.
Conclusions
The comparison of records from measurements carried
out upwards and downwards provides the proof of high
conformity of measurements in both directions in all
channels and it means that the localization and size of
measured deviations are real. The indication of the
deviation by ‘I’ and ‘W’ channels is correct only in the
case when the signal of these channels is significant and
on the contrary, the ‘S’ and ‘O’ signals are almost none
or only weak. During the development of the equipment
we have found out that the measured signals of ‘S’
channel are sensitive especially to changes of material
properties on contrary to our assumptions including its
sensitivity to the diameter changes of tubes. With
respect to this fact the measurements of tube diameter
with ‘S’ channel were replaced by measurement of
signals gained with addition of new ‘DIA’ capacity
transducers. The attained summary of measurement
results on reforming tubes assists in the evaluation of
CCT condition and their correct shutdown timing or
exchange.
Fig. 4 Damaged reforming tube 5F
Obr. 4 Poškodená reformingová rúra
Literature
[1] PETRÁŇOVÁ, A., ZIFČÁK, P., BRZIAK, P., BEZECNÝ, J.
Operation cabality of centrifugally cast tubes serviced by
chemical and petrochemical industry. In 22nd Internation
Conference. May 2012. Košice. ISBE 978-80-553-0912-5
[2] ZIFČÁK, P., PINCEŠ, B. Technická správa VÚZ PI SR 222/2000
ME 175: Kontrola reformingových rúr. Bratislava 2010
Fig. 5 Effect of surface roughness on the size of the measured
deviation "DIA"
Obr. 5 Vplyv povrchovej drsnosti na veľkosť nameranej odchýlky
„DIA“
[3] ZIFČÁK, P., PETRÁŇOVÁ, A., PINCEŠ, B. Technická správa
VÚZ PI SR : 222/2000 ME 091: Kontrola radiačných rúr v peci
17H301. Bratislava 2011
Review: prof. Ing. Františka Pešlová, PhD.
doc. Mgr. Ivan Kopal, PhD.
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Zkušebnictví, měřictví, laboratorní metody
Testing, Measurement, Laboratory Methods
Coefficient of Variation Measurements of Yarns
Meranie hmotnej nerovnomernosti priadzí
doc. Ing. Pavol Lizák, PhD., Ing. Jaroslav Ligas, PhD., University of Alexander Dubcek of Trencin, Faculty of
Industrial Technology, Department of Industry design, Ruzomberok, Slovakia
The non-uniformity is the fluctuation of properties of linear fabric from one measurement to the nth. Variation in
performance is reflected in the quality of linear fabric which affects other processing capabilities and quality of
surface fabrics made of it. From this perspective, it is necessary to evaluate the inequalities that have been
transferred to different units that were created to establish this important characteristic. This work has the task to
penetrate the problem of measured material inequalities and create a comprehensive overview of the principles and
instruments by which it is evaluated. The output, by which we detect unevenness may be taken in the graphic form
(signal from the device), which can be used for observation of the profile of yarn or figures.
Nerovnomernosť je kolísanie vlastností dĺžkovej textílie od jedného merania k n-tému. Kolísanie vlastností sa
prejavuje na kvalite dĺžkovej textílie, ktorá tým ovplyvňuje ďalšie možnosti spracovania, aj kvalitu plošnej textílie
z nej vyrobenej. Z tohto pohľadu je potrebné hodnotenie nerovnomernosti, ktoré bolo prevedené na rôznych
prístrojov, ktoré boli vyvinuté na stanovenie tejto dôležitej charakteristiky. Tieto prístroje pracujú na rôznych
princípoch merania, napr. meranie nerovnomernosti na prístroji Uster Tester 4 pracuje na tzv. kapacitnom
princípe, naproti tomu meranie na prístrojoch CTT a QQM pracujú na optickom princípe. Taktiež aj výsledky na
týchto prístrojoch ktoré sa dosiahli sú rôzne. Štúdium tohoto fenoménu sa budú zaoberať ďalšie výsledky ktoré budú
publikované. Táto práca ma za úlohu vniknúť do problematiky merania hmotnej nerovnomernosti a vytvoriť ucelený
prehľad princípov a prístrojoch pomocou ktorej je hodnotená. Ako výstup, pomocou ktorého detekujeme
nerovnomernosť može byť grafický (signál z prístroja), kde je možný vidieť profil priadze alebo čiselný údaj (CV,
index nerovnomernosti). Hodnotenie nerovnomernosti je dôležité nielen pri hodnotení kvality priadze ale taktiež aj
pri zistovaní chýb ktoré sa stali pri výrobe.

Variation matter fibers section or certain sections of
length for length fibrous formation may be caused by:

random distribution of fibers in the cross section of
the fiber unit for measuring length. (fig. 1)
imperfections in manufacturing (fig. 3)
Fig. 3 Fault in yarns
Obr. 3 Chyby v priadzi
Coefficient of variation affects a number of features of
the yarn (fineness, twist) and the flat fabric (surface...).
Therefore, there is the effort to produce yarns with the
lowest CV.
Quadratic uneven material
Fig. 1 Variable number of fibers in the yarn cross-section
Obr. 1 Premenlivý počet vlákien v priečnom reze priadzí

The coefficient of variation of length segments of fiber
weight unit
random nature of the fiber (fig. 2)
L
CV 
100 1
(m  m ) 2 .dl
m L 0
(1)
Linear material unevenness
It expresses the mean linear deviation from the mean
weight of the long span section of the fiber department.
Fig. 2 Different fiber diameter
Obr. 2 Rozdielny priemer vlákien
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Testing, Measurement, Laboratory Methods
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
L
U
100
m  m .dl
m .L 0
(2)
QQM - It is a portable device for rapid quality control
of yarn. The system consists of a measuring head
(optical sensors) for self-sensing surface unevenness
and yarn PSION terminal that communicates over the
measurement of sensor data captured and recorded.
Special software ensures the preservation of these
values and on - line analysis direct to the terminal.
Limit uneven
Limit non-uniformity is the smallest possible nonuniformity and its ultimate relationship:
2
Methods of material inequalities measuring
CTT - Manufactured by Lawson Hemphill, this device
is used for the analysis of yarn. CTT in the fig. 1 is
continue tension transport, which means that the device
is working under constant tension. It is used for such
measurements CV, hairiness and yarn diameter [2].
Fig. 4 Device Uster tester
Obr. 4 Aparatúra Uster tester
Fig. 7 CTT tester
Obr. 7 Tester CTT
Uster tester 4 - The principle is based on indirect
measurements of fluctuating weight of linear fabric that
passes between the capacitor plates. Linear fabric
replaces the capacitor dielectric, as shown in fig. 5.
Conclusions
CVlim
 v 
100

. 1   p 
n
 100 
(3)
Material yarn unevenness is an important component of
the overall evaluation of the quality of the yarn and it is
measured by help of standard (fig. 8 and fig. 9).
Fig. 5 Equipment for material inequalities measuring
Obr. 5 Zariadenie pre meranie nerovnosti materiálu USTER 4
Fig. 8 CV of tested samples
Obr. 8 Nerovnomernosť CV testovaných vzoriek
Linear variation of thickness of textiles in constant
motion oscillates between the capacitor plates as well as
capacity capacitor measuring, which is part of the
measuring oscillator (fig. 6). Capacitance change means
also change the frequency of the oscillator. This rate is
compared with the comparative frequency oscillator [1].
Fig. 9 Index of variation
Obr. 9 Index nerovnomernosti
Fig. 6 QQM System
Obr. 6 Systém QQM
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Zkušebnictví, měřictví, laboratorní metody
Testing, Measurement, Laboratory Methods
Fig. 10 Evaluation of parameter comparison with Uster statistics
Obr. 10 Porovnávanie vyhodnotených parametrov s Uster štatistik
Fig. 11 Sort of nops (left), thin (in the middle), and coarse (on the right), the size of places
Obr. 11 Druhy nopiek (vľavo), tenkých miest (v strede) a hrubých miest (vpravo)
Limit uneven and fancy uneven affected delicacy of
length fabric. To determine how big the place was
uneven index volatility, which it puts into a real
relationship measurment and uneven limit. The deal
case would be if the disparity index was equal first. In
fact, it is always greater than 1. For an even consider a
product with lower index of disparity.
getting 25% of the manufacturers who produce yarn
with low uneven material. Production of high quality
yarn but this is a lot of effort requires good material and
well-set technology. With Uster Statistics was found
that the examined yarn had a mean quality due to
achieved avalue of 50% of the schools, which is for the
parameters, the yarn achieved and such indicator is
suitable for export.
Index refers to the degree disparity measuring length
product and the actual product deviates from the ideal
product. Using this index can be compared with other
yarn manufacturers using Uster statistics.
Acknowledgement
We wish to thank the Slovak Grant Agency (KEGA: 002
TnUAD 4/2011) for the financial support.
Zellweger Uster Company collects worldwide data on
inequalities of produced yarns and parses the data
statistically [3]. Company issues at regular intervals of
information in graphs of an example of which can be
seen in fig. 10.
Literature
[1] Uster manual
[2] CTT manual
[3] LIZÁK, P., LIGAS, J. Základy textilnej a odevnej výroby. 2010
Wlok, 1979. 29 s. ISBN 978-80-969610-8-5
The graph fig. 11 can be read, or what to produce yarn
evenness average, above average or below-average. In
other words, if you get to a certain unevenness of our
yarn fineness [tex] at 50%, this means that the same
results achieved by 50% of producers in the world,
produced an average yarn. When we get to our yarn to
75%, manufactures 75% of this yarn manufacturers. It's
below average yarn. The effort of every manufacturer is
[4] MILITKÝ, J., IBRAHIM, S. Yarn hairiness complex
characterization. Proc. Annual fiber soc. conf. St Galen, 2004
Review: prof. Ing. Tatiana Liptáková, PhD.
doc. Ing. Iva Sroková, CSc.
93
Tepelná technika, pece, žárovzdorný materiál
Thermal Engineering, Reheating Furnaces, Refractory Material
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
tepelná technika, pece,
žárovzdorný materiál
Estimation of Specific Heat by Parametrical Fitting of Cooling Curves
Odhad tepelnej kapacity použitím parametrického fitovania kriviek chladnutia
doc. Mgr. Ivan Kopal, PhD., Ing. Karol Kováč, University of Alexander Dubček in Trenčín, Faculty of Industrial
Technologies, I. Krasku 491/30, 020 01 Púchov, Slovakia, Ing. Richard Puchký, VŠB-Technical University of
Ostrava, Faculty of Metalurgy and Materials Engineering, 17. listopadu 15, 708 33 Ostrava-Poruba, Czech Republic
This article deals with the study of the first order exponential model of the cooled solid body. Using this model, we
can estimate specific heat from experimental measured cooling curves of solid body. Our researched material is the
hardened polyurethane, which will be filled with single - walled carbon nanotubes in the future. This material is
developed in order to replace expensive titanium alloys. Cooling curves were recorded during the time of 6000
seconds and the maximum temperature difference was smaller than 0.5 K. Experimental data were measured on the
professional Thermophysical Transient Tester 1.02. We had to use the comparison method to determine specific
heat. The study of experimental data measured by pulse transient method showed that the experimental data
measured by this way fulfill the conditions of the first order exponential model including the radiation heat transfer.
V práci sa zaoberáme problematikou experimentálneho merania hmotnostnej tepelnej kapacity konštrukčných
materiálov aplikáciou exponenciálneho modelu prvého poriadku chladnúceho tuhého telesa. Analyzovali sme
dynamické teplotné polia vzorky tvrdeného polyuretánu, ktoré boli zaregistrované počas merania jeho základných
termofyzikálnych parametrov pulznou prechodovou metódou. Materiálom skúmaným v našej práci je tvrdený
polyuretán, ktorý má byť v budúcnosti plnený uhlíkovými nanorúrkami, a ktorý je vyvíjaný pre potreby náhrady za
drahé titánové zliatiny. Experimentálne získané krivky chladnutia boli zaznamenávané presne 6000 sekúnd, pričom
teplotný rozdiel bol menší ako 0,5 K a vzorka chladla v prostredí stáleho podtlaku. Metódou najmenších štvorcov
s aplikáciou nelineárnej robustnej iteračnej fitovacej procedúry s algoritmom tzv. dvojštvorcového váhovania sme
parametrickým fitovaním experimentálnej krivky chladnutia tuhého telesa odhadli relaxačný čas. Aby sme dokázali
vierohodne odhadnúť hmotnostnú tepelnú kapacitu, museli sme namerať polymér s tabelarizovanými parametrami –
polymetylmetakrylát. Pomocou porovnania relaxačných časov sme určili neznámu hmotnostnú tepelnú kapacitu.
Štúdia experimentálnych dát meraných pulznou prechodovou metódou uvedených v práci nám preukázala, že
experimentálne dáta namerané takýmto spôsobom spĺňajú podmienky exponenciálneho modelu prvého poriadku
rozšíreného aj o radiačný prestup tepla. Nami použitá metóda sa ukázala ako dostatočne efektívna pri zisťovaní
hmotnostnej tepelnej kapacity aj pri takomto type nízkovodivých materiálov.
The study of transition of material from nonequilibrium
state into a equilibrium state and understanding of this
process is a fundamental prerequisite for the production
of certain long term constructions, machines or another
devices. Coefficient of mass specific heat capacity and
also coefficient of thermal conductivity can be
considered as the main characteristics of the process of
degradation of the material, or of the process of its
ageing. Utility properties of these materials then depend
beside the chemical compound on the level of targeting
relaxation to equilibrium state. We can classify basic
thermophysical parameters as the important criteria for
the optimalization of material production. Materials
which are characterized by application as markedly
nonequilibrium states are for example polymers and
nanocomposites, concretes, glasses, steels, eventually
ceramics. Among these materials we can also assign the
new developed carbon nanocomposite with the
polyurethane matrix that is the subject of interest in our
investigation work. Measuring
thermophysical
parameters leads to filling important function at the
point of study of physical effects, which are for example
phase transitions or structural transformations [1-2].
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ISSN 0018-8069
Tepelná technika, pece, žárovzdorný materiál
Thermal Engineering, Reheating Furnaces, Refractory Material
First order exponential model
Simple first order exponential model is analytical
model, which can be used for describing the cooling of
non-moving solid body in non-moving incompressible
liquid. This model is valid under following conditions:
the first condition of validity of exponential model is
that solid body cannot be in contact with other
surrounding solid bodies; geometrical dimensions of
solid body, material properties and its thermophysical
parameters are not in dependency on temperature and
three-dimensional space; the solid body cannot contain
any internal heat sources inside and cooling must be
must at the constant coefficient of heat transfer of
diffusivity. Before the start of cooling process the
temperature in all volume of solid body must be the
same and surrounding background must have constant
temperature during the process of cooling. The
temperature difference between the solid body and
surrounding backgrounds must be very small, because
we ignore the radiation mechanism of heat transfer.
After that we can describe process of cooling of solid
object by Fourier’s partial differential equation of nonstationary heat transfer and it deals with the fact that
heat accumulated in the volume of matter takes out only
through surface of matter.

 
T r , t 
(1)

c
V p t dV   S n  q dS
The symbols represent the following variables: ρ –
density of material of solid body, cp – specific heat
capacity of material of solid body at constant pressure,
V – volume of solid body, S – surface of full heat
transfer surface of solid body with surrounding
background, T – time and spatial dependent temperature
of solid body (dynamic temperature field), t – time of

cooling of solid body, q – vector of density of thermal
flow which flows out from volume of solid body

through full heat transfer surface, n – unit normal
vector, which directs out from volume of solid body.
When we resolve equation according to mentioned
conditions we can get analytical solution in form of
simple temperature function.
t

τ
(2)
T t   T   T0  T  e
The value tau is very interesting because it centers all
materials constants to one [3-4].
 Vc p  c p L
(3)


hc S
hc
data belongs to estimated techniques and it is analogous
to the prevalent majority of estimated techniques
because it utilizes statistical method of the smallest
squares and it uses minimization of sums of squares
residues and it is defined as
n
min SSE  min   Ti  Tim  .
2
(4)
i 1
Thermal function of exponential model is, of course,
non-linear relative to parameter of relaxation time.
Therefore, for its trustworthy statistical estimation, it is
necessary to apply some of the available algorithms of
non-linear method of the smallest squares [5].
Results and discussion
Polyurethane matrix of future nanocomposite, which
was tested by pulse transient method at the professional
Thermophysical Transient Tester 1.02 with length of
exciting thermal impulse 13 seconds at the feeding
voltage of area source impulse approximately 1.8 V and
supply current 1.4 A and it was used in our analyses for
the application of first order exponential model. Process
of cooling of specimen after its thermal stimulation was
monitored during the following 6000 seconds
approximately.
The fig. 1 shows adjusted experimental curves of
cooling of investigated polyurethane specimen for eight
measurements. From the process of the next data
processing, we excluded those thermal functions which
obviously do not show the character of exponential
temperature drop in dependency on time.
Fig. 1 Adjusted curves of polyurethane cooling for eight measurements
Obr. 1 Upravené krivky chladnutia poyuretánu pre osem meraní
Parametric fitting of experimental data
Identification of constant relaxation time in the process
of parametric fitting of experimental time dependency
of temperature of solid body is based on its statistical
estimation. Experimental data are compared with their
analytical model and from this comparison, there can be
done the estimation of the correct value of unknown
parameters of model – in our case it is the correct value
of relaxation time. Parametric fitting of experimental
Fig. 2 Arithmetical average of selected thermal functions for
polyurethane and its fit1
Obr. 2 Aritmetický priemer vybraných teplotných funkcií pre
polyuretán a ich fit1
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Thermal Engineering, Reheating Furnaces, Refractory Material
We designed the thermal function from experimental
data which were chosen for the next analysis which
introduces its arithmetical average. From fig. 2, it is
evident, that the average time history of temperature for
specimen cooling is relatively too little rustled and it
makes good assumption for its next analysis which was
carried out by help of the specialized software working
tool Curve Fitting Toolbox of the system Matlab®. We
subdued our thermal function to the introduced tool for
parametrical fitting of experimental data by thermal
function of first order exponential model for solid body
which is cooled with constant relaxation time in form of
Eq. (2). In the tab. 1, we present the results of the
process of parametrical fitting of experimental data,
which enabled us to identify relaxation time of the
process of specimen cooling.
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Fig. 3
Adjusted curves of polymethylmethacrylate cooling
for eight measurements
Obr. 3 Upravené krivky chladnutia polymetylmetakrylátu pre
osem meraní
Tab. 1 Relaxation time and monitored statistical index SSE of
parametric fitting for polyurethane
Tab. 1 Relaxačný čas a sledovaný štatistický ukazovateľ SSE
parametrického fitovania dát pre polyuretán
Sample
Polyurethane
τ [s]
527.3
CI [s]
526.5-528.2
SSE
0.00445
We used the comparative method for resolution of our
introduced problem which consists of the comparison of
relaxation times of specimen of the material which is
well-known tabulated material and thermo-physical
parameters. These two different materials were cooled at
equivalent laboratory conditions and both specimens have
equivalent geometrical configuration. Presentation of the
equation from this comparison of two relaxation times
 E E c p L  e


e
 cp L
The relation in form
 E
cp 
cp ,
E 
(5)
E
(6)
E
is the result for the weight specific heat of our material
where the index E belongs to specimen of the material
with well-known parameters or it can also be called the
reference standard. We chose polymethylmethacrylate as
areference standard because it belongs to heat lowconductive polymeric materials as well as polyurethane.
In fig. 3, we present the experimental cooling curves of
PMMA and the results of parametrical fitting of
experimental data and its average are shown in the fig. 4.
The results of fitting of PMMA and monitored statistical
index of experimental data are presented in the tab. 2.
Fig. 4
Arithmetical average of selected thermal functions for
polymethylmethacrylate and its fit
Obr. 4 Aritmetický priemer vybraných teplotných funkcií pre
polymetylmetakrylát a if fit
The values of parameters of reference standard for
calculation of specific heat are introduced in the tab. 3.
According to relation Eq. (6), we inducted values from
tab. 3 and we calculated weight specific heat which has
value cp = 1439.6 J.K-1.kg-1.
Tab. 3 Calculation parameters used for for polyurethane and
polymethylmethacrylate
Tab. 3 Výpočtové parametre použité pre polyuretán
a polymetylmetakrylát
Sample
Polyurethane
PMMA
cp [J.K-1.kg-1]
?
1470
Ρ [kg.m-3]
1120
1200
τ [s]
527.3
576.9
Conclusions
Using two consecutive independent measurements, our
analysis of experimental data shows that the specimen
of hardened polyurethane tested by pulse transient
method is cooled in accordance with first order
exponential model.
Literature
[1] KOPAL, I., HUTYRA, J., MOKRYŠOVÁ, M. Automated Image
Tab. 2 Relaxation time and monitored statistic index of parametric
fitting for polymethylmethacrylate
Tab. 2 Relaxačný čas a sledovaný štatistický ukazovateľ SSE
parametrického fitovania pre polymetylmetakrylát
Sample
PMMA
τ [s]
576.9
CI [s]
575.8-578
SSE
0.00795
Analysis for Defects Detection in Polymer Materials. In:
TRANSCOM 2005, Section 6, Žilina: Žilinská univerzita, 2005.
ISBN 80-8070-418-X, p. 149-152
[2] KOPAL, I. Thermal data analysis in pulsed phase thermography
by infrared scanned detector camera. In: 22nd Danubia-Adria
Symposium on experimental Methods in Solid Mechanics, Parma:
University of Parma, 2005, p. 14-15
[3] KOPAL, I., MOKRYŠOVÁ, M., ŠVECOVÁ-MOŠKOVÁ, Z.
The specific heat of rubber blends measurement. In: Trends in the
development of machinery and associated technology TMT 2007,
96
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Tepelná technika, pece, žárovzdorný materiál
Thermal Engineering, Reheating Furnaces, Refractory Material
11th International research/expert conference Proceedings,
Hammamet, Turkey, september 5-9, 2007. 8, p. 543-546. ISBN
978-9958-617-34-8
[4] RUŽIAK, I., VALÁŠEK, R., SUCHÁ, D., VAVRO, J.
Thermovision Inspection of Rubber heating in Process of Tension.
In: The 12th International Conference on Problems of Material
Engineering, Mechanics and Design, Trenčín: TnUAD, 2007.
ISBN 978-80-969728-0-7
[5] KOPAL, I., KOŠTIAL, P. Vyšetrovanie termofyzikálnych
parametrov materiálov I: Exponenciálny model chladnúceho
telesa [CD-ROM]. Ostrava: Vysoká škola báňská-Technická
univerzita Ostrava, Fakulta metalurgie a materiálového
inženýrství, Katedra materiálového inženýrství, 2010. ISBN 97880-248-2203-7
Review: prof. Dr. Ing. Milan Sága
prof. Ing. Milan Žmindák, PhD.
_____________________________________________________________________________________________
Dohoda Mittalu s Paříží? Francouzské odbory viní Hollanda ze zrady
Denik.cz
1.12.2012
Francouzským odborům se nelíbí dohoda tamní vlády a největší světové ocelářské skupiny ArcelorMittal
o řešení sporu o ocelárnu Florange v severovýchodní Francii. Dohoda odvrátila propouštění poté, co
firma v ocelárně uzavřela dvě vysoké pece. Odbory však obvinily francouzského prezidenta Françoise
Hollanda ze zrady, napsala agentura Reuters.
Stěžovali jsme si na bývalého prezidenta Nicolase Sarkozyho, ale Francois Hollande si nevede lépe,"
uvedl odborář Frederic Maris ze svazu CGT. V budoucnosti očekáváme to nejhorší," dodal. Společnost v
rámci dohody slíbila další investice do ocelárny za 180 mil. eur (4,5 mld. Kč). Podle serveru france24.com
ale odbory pociťují zklamání a pochybují o slibech, které skupina dala. „Jsme ve válečném stavu," uvedl
představitel odborového svazu CFDT Edouard Martin. „Viděli jsme dřívější sliby šéfa podniku Lakšmího
Mittala, ze kterých nic nevzešlo. Takže nenecháme nic projít bez boje," dodal.
ArcelorMittal potřebovala ve Florange uzavřít kvůli dlouhodobé nerentabilnosti dvě vysoké pece, které
zaměstnávají asi 630 lidí z celkového počtu 2700 pracovníků ocelárny. Vláda hrozila firmě, že pokud
pece uzavře, ocelárnu zestátní. Francouzská podnikatelská organizace MEDEF tuto hrozbu označila za
skandální a varovala, že postoj vlády by mohl ohrozit zahraniční investice ve Franci.
Investice společnosti ArcelorMittal do ocelárny, které v pátek oznámil premiér Jean-Marc Ayrault, mají být
rozloženy do pěti let. Žádné propouštění z důvodu nadbytečnosti nenastane, jak prohlásil předseda vlády.
Podle Eduarda Martina však ocelárna potřebuje renovace nyní, ne až za pět let. Někteří dělníci jsou prý
zklamaní, že podnik nebyl znárodněn, jak dříve hrozil prezident Hollande. Že se tak stane a podnik
dočasně přejde pod správu státu, byli zaměstnanci přesvědčováni až do poslední chvíle, řekl Martin.
Vládu podle webu lemonde.fr obvinil, že po celou dobu diskusí o budoucnosti podniku lhala. Paříž tvrdí,
že prostředky nátlaku s oznámením dohody nezmizí. Pokud ArcelorMittal nebude držet slovo, jsou vždy
připraveny jiné alternativy k intervenci, jak řekl podle france24.com ministr práce Michel Sapin.
ArcelorMittal se podle Le Monde k dohodě vyjádřila pozitivně: „V rámci aktuálního ekonomického
prostředí je to dobrá dohoda," uvedl podle webu zástupce skupiny Henri Blaffart v prohlášení. Firma
rovněž odmítla obvinění, že ve Francii porušila své sliby. ArcelorMittal zaměstnává ve francouzských
závodech kolem 20.000 lidí.
SB
97
Tepelná technika, pece, žárovzdorný materiál
Thermal Engineering, Reheating Furnaces, Refractory Material
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
The Thermophysical Parameters Study of Car Seat Covers with Different Thickness
Štúdium termofyzikálnych parametrov autopoťahov rôznej hrúbky
doc. Mgr. Ivan Kopal, PhD., Ing. Karol Kováč, Ing. Silvia Uríčová, Ing. Mária Bačíková, University of
Alexander Dubček in Trenčín, Faculty of Industrial Technologies, I. Krasku 491/30, 020 01 Púchov, Slovakia,
In this article we present the termophysical parameters study of car seat covers which have different thickness. Our
specimens consist of three layers of textiles. For measurement of thermophysical parameters we used pulse transient
method. By this method we can measure three basic thermophysical parameters, such as thermal conductivity,
thermal diffusivity and specific heat and all these parameters can be obtained only from one measurement. We
measured six specimens with different thickness under the constant pressure at two different temperatures which
were 293.15 K and 305.15 K. All measured thermophysical parameters have quite low increasing tendency at
increasing temperature. Presented graphs and figures show that thermal diffusivity, thermal conductivity and
specific heat have increasing character which is similar to the increasing character of specimen thickness.
V tomto článku sa venujeme štúdiu termofyzikálnych parametrov viacerých vzoriek poťahov pre autosedačky, ktoré
majú rôznu hrúbku. Skúmané materiály sú zložené z troch vrstiev. Prvú vrstvu predstavuje tkanina vyrobená z PES
vlákien, druhú tvorí PUR pena a tretiu, spodnú vrstvu PES pletenina. Jednotlivé vzorky sa líšia druhom použitej
väzby, dostavou osnovy a útku, plošnej a objemovej hmotnosti a hrúbkou PUR peny. Na meranie termofyzikálnych
parametrov sme použili pulznú prechodovú metódu. Touto metódou dokážeme určiť tri základné termofyzikálne
parametre z jediného merania, a to teplotnú vodivosť, tepelnú vodivosť aj hmotnostnú tepelnú kapacitu z maxima
krivky teplotnej odozvy. Prezentované výsledky sú pri dvoch rôznych teplotách 293,15 K, čo je typická laboratórna
teplota a 305,15 K, čo je odhadovaná teplota ľudského oblečenia pri kontakte s autopoťahom. Tepelný impulz
použitý pri meraniach bol generovaný stálym prúdom 1 A pri časovom účinku 1 s pre tenšie vzorky, ktoré majú
hrúbku do 3 mm a pre hrubšie vzorky bol časový účinok zvýšený na 1,5 s kvôli dosiahnutiu vyššej teplotnej odozvy. Z
výsledkov meraní môžeme usúdiť, že všetky merané termofyzikálne parametre zaznamenali relatívne malý nárast
hodnôt pri vyššej teplote. Prezentované grafy dokazujú, že teplotná vodivosť, tepelná vodivosť a hmotnostná tepelná
kapacita vykazujú vzrastajúcu tendenciu v závislosti od hrúbky. Tento vzrastajúci charakter pri všetkých troch
termofyzikálnych parametroch sa však nedá považovať za lineárny, pretože rôzna hrúbka vzoriek sa mení len
vplyvom rôznej hrúbky strednej vrstvy, ktorou je polyuretánová pena.
Nowadays, increased attention is paid to the study of
composite materials properties in a wide range of
applications. The paper deals with covers for car seats
with different thickness. These materials, usually
represented by three-layer composites are the subject of
research especially in terms of thermal properties.
Therefore, we focused on the study of basic
thermophysical parameters that can be used for perfect
description of heat transfer in solids. In the world, the
research has been carried out in various ways, but it
mainly deals with providing comfort to passengers who
spend long hours driving a car [1].
Composition of car seat covers
Understanding the dependence of thermophysical
parameters on the thickness of used materials or
different types of materials can indicate a lot about
further development of these complex textiles. When it
comes to passengers it is important to achieve appropriate
conditions in two very different situations. In winter
good heat transfer is required through the car seat covers
from the heated car seats to the passenger and in summer
we need to achieve exactly opposite effect and it means
that we need to provide sufficient diversion of heat from
the passenger to the car seat [2].
Using the pulse transient method, one measurement is
sufficient for measuring three basic thermophysical
parameters - thermal conductivity, thermal diffusivity
and specific heat. This method is included in the
dynamic group, i.e. transition methods that are used to
measure solids. The basic principle of this method is to
supply heat pulse through the planar heat source to the
sample, which had the temperature stabilized before the
measurement. Using a thermocouple, located on the
opposite side of the sample, as a heat source, we record
the dynamic thermal response. Subsequently, using the
schemes and the curve of the recorded temperature
The samples used in our work are three-layer textiles.
The top of the car seat cover is solid polyester fabric.
The lower part of this composite is polyester knitted
fabric, but this layer is significantly weaker. The layer
between these two mentioned layers of textiles is
polyurethane foam. Different thickness of polyurethane
foam produces various thick samples. The layers were
connected to three- layer textiles by using flame.
Pulse transient method
98
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ISSN 0018-8069
Tepelná technika, pece, žárovzdorný materiál
Thermal Engineering, Reheating Furnaces, Refractory Material
response we can calculate three thermophysical
parameters. Fig. 1 shows the principle of pulse transient
method [3].
Fig. 1 The principle scheme of the pulse transient method [4]
Obr. 1 Principiálna schéma pulznej prechodovej metódy [4]
The model is characterized by a temperature function
T h, t  
 h2 
Q
,
exp 
c p  t
 4t 
(1)
where Q=RI2t0 is the amount of heat generated by a heat
pulse through the unit area, R is the electrical resistance
of the heat source, I is the current supplied at time t0, ρ
is the density and cp and α are unknown thermophysical
parameters (heat capacity and thermal conductivity).
Temperature function (1) is a solution of the equation of
heat with respect to the appropriate boundary and initial
conditions. To determine the thermophysical properties
we use maximum temperature response as an input.
Equations used for calculation of the thermophysical
parameters:
Heat capacity cp
c p  Q / Tm h 2e
(2)
Thermal diffusivity α
  h 2 / 2tm
(3)
Tm is the maximum temperature response at the time tm
and e is Euler's number. Third thermophysical
parameter, thermal conductivity λ is defined by wellknown relationship
(4)
  c p
Experimental procedure
For study of thermophysical parameters of car seat
covers we used the professional Thermophysical
Transient Tester 1.02 developed at the Physics Institute
of Slovak Academy of Science. This tester consists of
vacuum chamber, vacuum pump, isothermal chamber,
programmable thermostat, personal computer with
specialized software and electronic unit. In the vacuum
chamber, there is specimen holder and specimen set
including measuring probes. Any temperature gradient
along the specimen set is suppressed by isothermal
shield. The temperature of the specimen holder controls
the thermostat. Low heating rates are used to keep
quasi-isotherm measurement conditions and to reduce
radiative heat losses. We can measure in vacuum up to
0.1 Pa by using vacuum cover [5]. Fig. 2 presents fully
automated measurement equipment.
Fig. 2 The experimental equipment, isotermal chamber, vacuum
chamber, specimen holder, specimen set with measuring
probes
Obr. 2 Experimentálna aparatúra, izotermická komora, vákuová
komora, držiak vzorky, vzorková sada
Our specimen set has five pieces of cylindrical shape,
because we need to simulate a geometrically unbounded
specimen set which was placed in the isothermal
vacuum chamber. The nickel folium 20 μm thick, heat
source with radius of 0.015 m has the same specimen
radius that is placed between the second and the third
part. The Chromel-Alumel thermocouple was placed
between the third and the fourth part of the specimen
set. The second connection of thermocouple was placed
on heat exchanger. There the constant temperature was
kept by thermostat and measured by 100 Ω platinum
resistance. All parameters of the specimen required for
fully automatic data analysis by specialized software of
the used experimental equipment are presented in the
tab. 1. The symbols represent the following variables:
d – specimen diameter, h – thickness of the middle part
of the specimen set, ρ – density of material.
Tab. 1 The parameters of the specimens
Tab. 1 Parametre vzorky
specimen d [mm] h [mm]
ρ [kg.m-3]
30
2.4
183.75
T03
30
2.1
206.19
T04
30
4.4
115.39
T06
30
6.4
90.28
T07
30
4.6
93.33
T09
30
7.5
82.47
T13
Heating up the sample was provided by a current pulse
of the 1 s duration at driving voltage of 1.4 V and
a supply current of 1 A for specimens the thickness of
which was less than 3 mm and 1.5 s long current pulse
was used for other specimens for better temperature
response. The temperature response of specimen was
measured during 600 s. The time of temperature
stabilization of specimen at each temperature was
100 minutes.
Results and discussion
Fig. 3 shows different thickness of measured specimens.
Different thickness of developed specimens is caused by
99
Tepelná technika, pece, žárovzdorný materiál
Thermal Engineering, Reheating Furnaces, Refractory Material
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
using different thick center layer in three-layer textiles.
This polyurethane foam changes the values of
thermophysical parameters, because top and bottom
layer are similar in each specimen.
Fig. 6
Specific heat capacity of car seat covers for two temperatures
293.15 K and 305.15 K
Obr. 6 Hmotnostná tepelná kapacita poťahov pre teploty 293,15 K
a 305,15 K
Fig. 3 Values of thickness of six specimens
Obr. 3 Hodnoty hrúbky pre šesť vzoriek
The values of three-layer textiles, which were measured
by pulse transient method, can be considered only to
effective values of thermophysical parameters. At the
fig. 4 is shown that thermal diffusivity has a significant
increase in the last two types T07 and T13.
Conclusions
In this article we present the study of thermophysical
parameters of car seat covers. Presented figures
demonstrate that thermal diffusivity, thermal
conductivity and specific heat capacity have increasing
character in dependency on increasing thickness. This
increasing character of all the three thermophysical
parameters cannot be considered as linear dependence,
because different thickness of specimens is changed
only by using different thickness of center layer of
composite - polyurethane foam. All presented values
have relative deviation smaller than 2 percent.
Literature
[1] WIGGINS, K.G., ALLARD, J.E. The evidential value of fabric
car seats and car seat covers. In: Journal of the Forensic Science
Society. ISSN: 0379-0738, 1987, vol. 27, no 2, p. 93-102
Fig. 4
Thermal diffusivity of car seat covers for two temperatures
293.15 K and 305.15 K
Obr. 4 Teplotná vodivosť poťahov pre 293,15 K a 305,15 K
Thermal conductivity has almost same increasing
character as increase thickness of specimens. This
dependency is presented at the fig. 5. At the all figures
are presented values at two temperatures 293.15 K and
305.15 K. Thermophysical parameters have always
small increase with increasing of temperature. At the
Fig. 6 we present values of specific heat capacity. This
parameter has the same dependency as thermal
diffusivity.
[2] TÜLIN G.C., FATIH C., BABALIK K. The effects of ramie
blended car seat covers on thermal comfort during road trials. In:
International Journal of Industrial Ergonomics. ISSN: 0169-8141,
2009, vol. 39, no. 2, p. 287 – 294
[3] KUBIČÁR, Ľ. Pulse Method of Measuring Basic Thermophysical
Parameters. In: Comprehensive Analytical Chemistry. ISSN
0069-8024, 1990, vol. XII, p. 350
[4] KUBIČÁR, Ľ et al. Thermophysical parameters measurement by
classic and transient methods. Nitra: CPU Nitra, 2000, ISBN 808050-361-3
[5] BOHÁČ, V., DIEŠKA, P., KUBIČÁR, Ľ. The Heat Loss Effect at
the Measurements by Transient Pulse Method. In: Measurement
Science Review. ISSN 1335-8871, 2007, vol. 7, no. 2, p. 24-27
Review: prof. Dr. Ing. Milan Sága
prof. Ing. Milan Žmindák, PhD.
Fig. 5
Thermal conductivity of car seat covers for two temperatures
293.15 K and 305.15 K
Obr. 5 Teplotná vodivosť poťahov pre 293,15 K a 305,15 K
100
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ISSN 0018-8069
Tepelná technika, pece, žárovzdorný materiál
Thermal Engineering, Reheating Furnaces, Refractory Material
Influence of Electrical Properties on the Thermal-insulation Properties of the
Textile Fabrics
Vplyv elektrických vlastností na tepelno-izolačné vlastnosti tkanín
doc. Ing. Pavol Lizák, PhD., Ing. Jela Legerská, PhD., Ing. Jaroslav Ligas, PhD., University of Alexander
Dubcek of Trencin, Faculty of Industrial Technology, Department of Industry design, Ruzomberok, Slovakia
This paper presents and compares the evaluated electrical and thermal properties of fabrics. The results obtained
from two types of nonconductive fabrics for different material composition were discussed. Measurements were
made by electrical methods that have satisfactory predication about conductance and transferring the electrostatic
charge and heat from the surface. The aim was to compare each non-homogeneous textile materials and evaluate
the effect of electrical properties on thermal insulation properties. Measurement results showed significant
dependence on the measured properties. Known fact confirmed better electrical properties compared to
polypropylene with cotton fabrics. On the other hand, the polypropylene fabric shows better thermal insulation.
Cieľom príspevku bolo hodnotenie elektrických a tepelných vlastností tkanín. Diskutované boli výsledky získané
z dvoch druhov nevodivých tkanín o rozdielnom materiálovom zložení. Porovnávali sa tkaniny vyrobené zo 100%
bavlny s tkaninami vyrobenými zo 100% polypropylénu. Merania boli robené elektrickými metódami, ktoré majú
dostatočnú vypovedajúcu schopnosť o vedení a odvádzaní elektrostatického náboje a tepla z povrchu tkaniny.
Elektrické vlastnosti boli merané pomocou trojelektródového systému. Výsledkom meraní boli hodnoty plošného
odporu tkanín ρs [Ώ.m]. Tepelné vlastnosti boli merané konduktívnou metódou prestupu tepla cez tkaninu priamo do
prostredia. Výsledkom meraní boli hodnoty tepelného odporu R [W-1.m2.K1] a tepelnej vodivosti tkanín K [W.m-1.K-1].
Cieľom bolo vzájomne porovnať tieto nehomogénne textilné materiály a ohodnotiť vplyv elektrických vlastností na
tepelnoizolačné vlastnosti. Výsledky meraní ukázali na bezvýznamnú závislosť medzi sledovanými vlastnosťami.
Meraniami sa potvrdila známa skutočnosť lepších elektrických vlastností bavlnených tkanín oproti
polypropylénovým tkaninám. Polypropylénové tkaniny naopak vykazujú lepšie tepelno-izolačné vlastnosti.
Zaujímavým záverom bola anizotropia elektrických vlastností v smere osnovy a útku nameraná u polypropylénových
tkanín. Ukázalo sa tiež, že odporová metóda merania elektrických vlastností je nedostačujúca a je potrebné
elektrické vlastnosti hodnotiť aj metódami určujúcimi schopnosť tkaniny prijímať a odvádzať elektrostatický náboj
po indukčnom a triboelektrickom nabíjaní.
Non-metallic textile materials located in an electric field
behave as insulators, because most of the compounds
consist mainly of carbon, hydrogen, nitrogen and
oxygen and have electrons as charge carriers hard bound
to the atom core (shared covalent bonds with them) as
well as they are stationary [1]. Textiles are more
conductive which has been caused by moving electrons.
The energy (such as thermal) is needed for movement of
the electrons. Thus also content of the moisture to
influence increase the conductivity of the fibers. It is
known that non-metallic textile with synthetic fibers can
generate electrostatic charge during use. Potential spark
discharge especially in work clothes creates a significant
security risk. Equally unpleasant effects evoke an
electrostatic charge when wearing the clothes stick, spark
and have an increased ability to dirty. Evaluation of
electrical properties from the measurement indicates that
the size of electrostatic charges is directly related to the
size of the electrical resistance and thermal resistance
of textiles.
mechanisms of heat transfer are known: conduction,
convection and radiation. Heat is often transmitted by
a combination of all three mechanisms. Alternatively it
combines well with the change of water vapor and gases
[2]. Under the second law of thermodynamics, heat
spontaneously spreads a higher temperature to lower
temperature from place to place, thus the skin releases
the heat through clothing to the environment (the skin
when the temperature of skin is higher than the
environment temperature). It expresses the value of
thermal
conductivity
or
thermal
resistance.
Characteristics of textile insulators are that the electrical
resistance decreases with temperature (however, in the
case of the metal fibers, the electrical resistance
increases with temperature). The moisture content and
additives on fibers also reduce the electrical and thermal
resistance.
Experiment
Methods of the evaluation of electrical and thermal
properties of textiles include relatively large number of
today used methods for assessing electrical properties of
various materials and can be divided into two groups:
101
Textile materials transmit or receive (exchange) energy
through heat and thus perform the work. This energy
exchange process is called heat transfer [2]. Three basic
Tepelná technika, pece, žárovzdorný materiál
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Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
• method for measurement of electrical resistance
• measurement of capabilities of materials and products
levying an electrostatic charge as speed of decrease
electrostatic charge after charging corona discharge [3].
parameters, but from a different material composition.
Fig. 3 shows samples of fabric and they were evaluated
by the image analysis Nis Element [6]. Fabrics were
made of the same thread interrelated plain weave.
The fabric samples can be used for measurement of the
surface resistivity and vertical resistivity on the device
which consists of three circular electrodes (fig. 1).
Surface resistivity ρs [Ώ.m] was measured between
electrodes 1 and 2. For measuring surface resistivity of
fabric it is necessary to know the value of secondary
circuit electrodes and electrode distance [4].
Results
Fig. 1 Three electrodes system
Obr. 1 Systém 3 elektród
Fig. 2 Device Alambeta
Obr. 2 Prístroj Alambeta
Fig. 3 Samples of cotton and polypropylene fabrics
Obr. 3 Vzorky bavlnenej a POP tkaniny
The measurement of the thermal resistance was done on
the device Alambeta. It is an indirect measurement
method, which simulates and objectively evaluates the
thermal contact between the skin moisture and dry cloth
to short contact [5]. Model wet human skin is simulated
by textile knitwear COOLMAX FX-205 with
moistening of 1 ml solution with addition of detergent
of 1:50 (fig. 2). Results of measurements were: thermal
conductivity K [W.m-1. K-1] and the thermal resistance
R [W-1.m2.K1]. Measurements of electrical properties
were performed on samples of fabrics with similar
Measurement of electrical resistivity was made on
a device under the following conditions: test voltage
100 V, relative humidity 35%, temperature 21 °C
(samples were air-conditioned matured in the
conditioned environment for 24 hours.). Measurement of
thermal properties was made on the device Alambeta
under the following conditions: relative humidity 35%,
temperature 21 °C (samples were air-conditioned
matured in the conditioned environment for 24 hours.
The measured value was tested by program QC expert,
whether it is a normal distribution of data, homogeneous
and independent [7]. All measured data correspond to
these parameters. Correlation between electrical
resistivity and thermal resistance was calculated for both
types of fabrics and shows a simple linear correlation
(fig. 4, 5). The positive regression coefficient r reflects
a direct relationship between monitored properties.
However, if the approaching r = 0 we can say that the
measurements of thermal and electrical resistance is
independent. In this paper we evaluated the electrical
properties of the two types of materials.The cotton fabric
was based on knowledge of literary values of the
electrical resistance R for this range: from 106 to
1010 Ώ.m. Measured electrical resistance, averaged from
3.463.1011 to 4.275.1011 Ώ.m approaching this material
characteristics of synthetic fabrics.This fact suggests that
even in natural materials it is necessary to know the
value of electrical properties. The polypropylene fabric
was measured in relation to mean electrical resistance
from 6.286.1012 to 10.5.1012 Ώ.m Theoretical values of
electrical resistance of synthetic fibers is from 1012 to
1014 Ώ.m [9]. It was considered that electrical resistance
is closely related to thermal resistance. However the
results of the measurements did not show it.
Tab. 1 Results of measurements for parameters of fabrics
Tab. 1 Výsledné hodnoty meraných parametrov u sledovaných tkanín
Measurement values
K [Wm .K-1] mean value
K [Wm-1.K-1] standard deviation
K [Wm-1.K-1] confidence interval
R [W-1.m2.K1] mean value
ρs (Ωm) mean value - warp
ρs (Ωm) mean value - weft
ρs (Ωm) standard devation -warp
ρs (Ωm) standard devation -weft
-1
Cotton fabric
0.0633
0.008
0.0596-0.0670
0.0087
4.275.1011
3.463.1011
1.053.1011
0.3929.1011
102
Polypropylene fabric
0.0691
0.005
0.06740-0.0699
0.0115
6.286.1012
10.5.1012
2.500.1012
8.374.1012
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Tepelná technika, pece, žárovzdorný materiál
Thermal Engineering, Reheating Furnaces, Refractory Material
5. It has been proven that the thermal and electrical
resistance is in the direct correlation dependence
with insignificant low tightness.
6. Anisotropy of measurements of both properties
shows the importance of porosity fabric, which
influenced the monitored measurements. Therefore
it would be appropriate in the following research
work monitor the impact of porosity on these
properties.
Fig. 4 Regression dependence of polypropylene fabric
Obr. 4 Regresná závislosť POP tkaniny
Acknowledgement
We wish to thank the Slovak Grant Agency (KEGA: 002
TnUAD 4/2011) for the financial support.
Literature
[1] JAMBRICH, M., PIKLER, A., DIAČIK, I. Physics fibers, Alpha
1988, p. 513-515
[2] MURÁROVÁ, A., MURÁROVÁ, Z., Physiology and comfort
clothing, Bratislava 2011, ISBN 978-80-970966-3-2
[3] MARCIÁN, V., LEDROVÁ, Z., ŠANDA, K., FIŠÁROVÁ, H.,
Methods for characterization of electrical properties of textiles,
National professional conference, Textiles in the future, 2010
VÚTCH-Chemitex Žilina
Fig. 5 Regression dependence of cotton fabric
Obr. 5 Regresná závislosť bavlnenej tkaniny
[4] STN EN 31 092, Determination of physiological properties,
ÚNMS SR 1998
Conclusions
[5] VRBOVÁ, V., IN 23-304-02 01, Measurement of the thermal
properties of the device Alambeta, TU Liberec 2002
This study evaluation of the electrical and thermal
properties of fabrics was made for cotton and
polypropylene fibers.
[6] KŔEMENÁKOVÁ D., Image analysis in textiles, Textile
Science, TU Liberec 2004, p. 26-33
The conclusions of measurements are as follows:
1. Significant variability and anisotropy of electrical
properties is reflected in the measurements for
polypropylene fabric. It is possible that the
variability of measurements is caused by different
set in the direction of the warp and weft.
2. It was confirmed that electrical properties of the
natural material - cotton were partially better
confirmed in comparison to the synthetic
polypropylene fabric.
[7] MELON, M., MILITKÝ, J., Statistical analysis of experimental
data, Prague 1998, p .571-578, ISBN 80-7219-003-2
[8] MARŠÁLKOVÁ, M., Electrical behavior of fabrics with
antistatic properties and methods of their evaluation, Grants
Projects, TU Liberec 2009
[9] HALLIDAY, D., RESNICK, R., WALKER, J., Electricity and
magnetism , physics, part 3, Prague 2003, ISBN 80-214-1868-0
[10] LIZÁK, P., Technical textiles, FPT Púchov 2002, ISBN 80968674-0-7
[11] LIZÁK, P., LEGERSKÁ, J., KOJŠ, V., Thermal characteristics
of textile fabrics, International conference on problems of
materials enginering, mechanics and desing, Rajecké Teplice
2008
3. Resistance method has been proven that it has no
predictive value of the electrical properties of
fabrics.
4. Thermal properties were measured for fabrics
which were worse heat insulators than the
polypropylene fabric.
103
Review: prof. Ing. Darina Ondrušová, PhD.
doc. Ing. Iva Sroková, CSc.
Počítačová simulace, výpočetní metody
Computer Simulation, Computing Methods
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
počítačová simulace,
výpočetní metody
Determination of Mooney-Rivlin Parameters of Rubber Used for Rubberizing
of Steel cords as an Input for FEA Models of Tire
Stanovenie Mooney-Rivlinových parametrov nánosových zmesí oceľokordov
pre vstupy do MKP výpočtových modelov pneumatík
doc. Ing. Jan Krmela, PhD., Ing. Jozefína Drdáková, Ing. Ivan Kováč, Ing. Peter Vido, Ing. Michal Pastorek,
Ing. Monika Struharňanská, University of Alexander Dubček in Trenčín, Faculty of Industrial Technologies,
I. Krasku 491/30, 020 01 Púchov, Slovakia
The article deals with the determination of Mooney-Rivlin parameters of rubber used for rubberizing of steel cords
because the given parameters can be used as input parameters for computational models of tires. Important factors
that could significantly affect the accuracy of computational models of tires are closely connected with the critical and
initial conditions that have to be taken into account. The load, the geometry of the casing and also the material
parameters of individual parts of the tire casing can be included here. From the experimental aspect, it is very
important to determine the correct individual material parameters for each elastomeric part of the tire casing. Finite
element method (FEM) is commonly used for analysis (FEA) in the order to obtain the accurate results for tires. The
elastomeric parts are commonly modeled by using the Mooney-Rivlin material model that is described by MooneyRivlin material parameters. These parameters are calculated from the experimentally obtained dependencies of stress on
the strain and it is especially connected with the static tensile tests. The given mentioned parameters can also be used as
input data for the material description of the elastomeric matrix of steel cord belt in a computational model of a tire.
Článok sa zaoberá stanovením Mooney-Rivlinových parametrov nánosových zmesí oceľokordov ako vstupných
materiálových parametrov do výpočtových modelov pneumatík. V súčasnej dobe je jednou z najčastejšie
využívaných metód schopných riešiť nelineárne úlohy metóda konečných prvkov (MKP). Dôležitými faktormi, ktoré
môžu výrazne ovplyvniť presnosť výpočtu pneumatík, sú okrajové a počiatočné podmienky zohľadňujúce zaťaženie,
geometriu plášťa a tiež materiálové parametre jednotlivých materiálových oblastí plášťa. Z dôvodu čo
najpresnejších výsledkov z MKP analýz pneumatík je dôležité správne experimentálne stanoviť jednotlivé
materiálové parametre aj pre elastomérové časti plášťa, ktorým sa článok zaoberá. Záleží aj na zvolenom
materiálovom modeli správania sa materiálu. Pre elastomérové časti plášťa pneumatiky sa najčastejšie používa
Mooney-Rivlinov model správania sa materiálu, ktorý je popísaný Mooney-Rivlinovými materiálovými
parametrami. Tieto parametre sa vypočítajú z experimentálne získaných závislostí napätia od pomerného predĺženia
najmä zo statickej skúšky v ťahu. V článku sú uvedené vypočítané hodnoty Mooney-Rivlinových parametrov pre
vybraný elastomér – nánosovú zmes pre oceľokordy. Tieto parametre sú použité ako vstupné dáta pre materiálový
popis elastomérovej matrice v oceľokordových nárazníkoch vo výpočtovom modeli pneumatiky.
For computational modeling of tires it is important to
experimentally determine the material parameters used
for the description of each individual part of the
casing [1]. Several material models of the viscoelastic
behavior of the material are used for the description of
elastomer parts which also include the rubber for
rubberizing of steel cords. Mooney-Rivlin model which
is described by the Mooney-Rivlin parameters is most
often used for computational modeling of tires. These
mentioned parameters describe the strain-stress
behavior of elastomer parts of the tire casing and the
Mooney-Rivlin model can be well applied for the range
of strain up to 150%.
104
Hutnické listy č.7/2012, roč. LXV
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Počítačová simulace, výpočetní metody
Computer Simulation, Computing Methods
The tire casings reach the strain about 10-15%. Most of
it is in the top and bottom tread layer, in the sidewall of
the casing and at the point of contact with the ground.
For the description of the behavior of elastomers in the
tire casing is most commonly used the two-parameter
Mooney-Rivlin material model, which is sufficient.
   1
(6)
The dependency is obtained from the derived relations
of Mooney-Rivlin equation and on the basis of this
dependency, Mooney Rivlin parameters C10 and C01
(fig. 1) can be obtained by help of linear regression.
In this article the authors focus on the determination of
Mooney-Rivlin parameters C10 and C01 of selected
elastomers of drift rubber for steel cord belts.
Application of elastomer especially for steel cord
reinforcements has several purposes. Individual steel
cords must be insulated from each other which prevents
their mutual friction also it reduces the heat generation
while driving thus increasing the service life of the tire.
Experiment
To determine the basic Mooney-Rivlin parameters it is
necessary to carry out the mechanical tensile test for
a sample from the given elastomer. The tensile curve for
the elastomer has a specific course of sigmoid shape
with a relatively significant inflexion point.
As the result of the tensile test, the dependency of
tensile stress on strain was evaluated on the basis of the
graphical dependency of tensile force on the elongation.
Consequently, according to Mooney Rivlin twoparameter equation (1), the relationships for the
calculation of the material parameters C10 and C01 were
derived.
The Mooney-Rivlin two-parameter equation has the
form [2]:




F
 2C01    2  2C10 1   3
A0

(1)
where:
σ – stress acting in the sample [MPa],
F – loading force [N],
A0 – cross section of test sample [mm2],
C10 and C01 – Mooney-Rivlin parameters [MPa],
α – relative length [-].
Fig. 1 Determination of Mooney-Rivlin parameters according
to the derived equation
Obr. 1 Stanovenie Mooney-Rivlin parametrov podľa odvodenej
R rovnice
Results and discussion
Acquired Mooney-Rivlin parameters for deposited
rubber on steel cord belts are shown in the tab. 1.
The tables show the values for each deposited rubber
used for rubberizing. The values of the deposited rubber
for new steel cord belts are shown in tab. 1. The tab. 2
represents the values for deposited rubber on steel cord
belts but it is after its degradation. Samples were
degraded by the effect of aging. The values appear to be
different depending on the time of exposure to ozone.
This was the significant influencing factor of the course
of characteristics in comparison to the new elastomers.
Tab. 1 Values for deposited rubber of steel cord belts for a new
tire casing
Tab. 1 Hodnoty pre nánosové zmesi oceľokordových nárazníkov pre
nový plášť pneumatiky
Measured values
The simple modifying of the equation (1) is connected
with the linearization into form (2):
i
(2)
 C01  C10

1
21  3 
 i 
where:
λi – relative deformation for individual values of λ [-].
The equation for straight line:
y  ax  b
leads to this result:
y
i

1
21  3 
 i 
x
1A
F
[N]
167.3
Δl
[mm]
125.9
A0
[mm2]
12.89
l
[mm]
80.0
2A
169.3
114.1
13.99
80.0
3A
218.0
177.6
13.87
80.0
4A
134.0
219.3
12.84
80.0
5A
246.0
191.2
12.91
80.0
sample
Calculated values
sample
σ
[MPa]
ε
[%]
C10
[MPa]
C01
[MPa]
1A
12.983
157.3
0.037
0.813
2A
12.106
142.7
0.037
0.863
3A
15.721
222.1
0.035
0.136
4A
10.440
274.1
0.019
0.231
5A
19.062
238.9
0.038
0.379
(3)
(4)
(5)
105
Počítačová simulace, výpočetní metody
Computer Simulation, Computing Methods
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Tab. 2
Values for deposited rubber on steel cords after
degradation by aging
Tab. 2 Hodnoty pre nánosové zmesi oceľokordov
po degradácii starnutím
Conclusions
Measured values
sample
F
[N]
Δl
[mm]
A0
[mm2]
l
[mm]
1B
168.7
112.7
13.87
80.0
2B
152.0
203.6
12.84
80.0
3B
259.3
180.1
12.91
80.0
Calculated values
sample
σ
[MPa]
ε
[%]
C10
[MPa]
C01
[MPa]
1B
12.163
141.0
0.040
0.187
2B
11.843
254.5
0.025
0.597
3B
20.095
225.1
0.046
1.040
Mooney-Rivlin parameters for each sample of deposited
rubber on steel cords belts will be used for
computational modeling of a radial tire as and it can be
seen in the fig. 2.
For computational modeling of tires, it is also necessary
to know the other material parameters of each individual
elastomeric and reinforcing part of the tire casing. These
parameters include Mooney-Rivlin parameters of the
tread, the deposited rubber layer of carcass, the inner
rubber, the sidewalls, the core, the bead, lateral wedge
and moduli of elasticity relating to reinforcing materials
(bead wire, steel cord and textile cords). Experimental
determination and specification of these material
parameters is constantly being solved within the works
of authors [3].
The specified Mooney-Rivlin material parameters will
be used for creation of the computational models of tire
casings and the response to the change of the material
parameters will be monitored. The computational model
of the tire will be subjected to strain-stress analysis at
first and subsequently, the results of experiments will be
verified by help of the test device called the static
adhesor.
The material parameters of the elastomers after a certain
form of degradation (for example: corrosion influence)
are very important inputs for the calculations.
Specified material parameters of elastomers will be
included into the computational model of a steel cord
belt where the objective is connected with the
simulation of the degradation of the belt of the tire
casing.
Literature
[1] KRMELA, J. Computational Modeling of Tyres Considering
Operating and Safety Requirements. Communications, Vol. 10,
Nr. 3, 2008, p. 61-65, ISSN 1335-4205
[2] ŠIMEK, I. Fyzika polymérov. Bratislava: CHTF-SVŠT, 1987,
230 p., (in Slovak)
[3] KOVÁČ, I., KRMELA, J. Determination of Modulus of
Elasticity of Tire Steel-cord Belts for Use in Tire FEA Models.
In The 16th International Slovak-Polish Conference Machine
Modeling and Simulations, 2011, Slovakia, pp. 73-78, ISBN
978-80-8075-494-5
Review: prof. Dr. Ing. Milan Sága
prof. Ing. Ján Vavro, PhD.
Fig. 2 Spatial computational model of a tire casing
Obr. 2 Priestorový výpočtový model plášťa pneumatiky
106
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Počítačová simulace, výpočetní metody
Computer Simulation, Computing Methods
Dynamic Analysis of Winding Mechanism during the Manufacturing Process
of Passenger and Freight Raw Car Tyres
Dynamická analýza ovíjacieho mechanizmu
a nákladných surových autoplášťov
pri
výrobe
osobných
prof. Ing, Ján Vavro, PhD., Ing. Ján Vavro, PhD., jr., Ing. Alena Vavrová, PhD., Ing. Petra Kováčiková,
Ing. Robert Vanc, Department of Material technologies and Environment, Faculty of Industrial Technologies,
University of Alexander Dubček in Trenčín, I. Krasku 1809/34, 020 01 Púchov, Slovakia
The given paper is closely connected with the dynamic analysis relating to the winding mechanism referring to
production or manufacturing of raw tyres for passenger as well as freight cars. The attention is mainly paid to the
calculation of normal force during the manufacturing process when the individual constituents of raw tyre are
pressed-in. The dynamic analysis as well as the calculation of the given normal force was done for raw passenger
car tyre which has 14 inches and 22.5 inches of wheel car diameter. The dynamic analysis of the lever mechanism
of winding arms has been done by relaxation method in the computer program Matlab. The desired stiffness for
individual elastic constituent parts, adhesion properties as well as any other important values were determined in
an experimental way and the whole analysis for the one lever of the winding mechanism was done in program
environment Working Model 3D.
Článok sa zaoberá dynamickou analýzou ovíjacieho mechanizmu pri výrobe osobných a nákladných surových
autoplášťov. Pozornosť je predovšedkým zameraná na výpočet normálovej sily pri zalisovavaní jednotlivých
komponentov pri výrobe 14“ osobného surového autoplášťa a 22,5“ nákladného surového autoplášťa. V článku je
stručne opísaná technológia procesu výroby zalisovania jednotlivých komponentov pomocou pákového ovíjacieho
mechanizmu. Dynamická analýza pákového mechanizmu ovíjacích ramien sa robila metódou uvoľnenia v programe
Matlab. Všetky potrebné tuhosti jednotlivých pružných členov, adhézne vlastnosti ako aj iné potrebné hodnoty sa
určili experimentálnym spôsobom. Celá analýza bola urobená pre jednu páku ovíjacieho mechanizmu
v programovom prostredí Working Model 3D. Zo simulácie pohybu mechanizmu pre reálne vstupné hodnoty boli
určené normálové sily valčekov prvej a druhej sady ovíjacieho mechanizmu. Správne zalisovanie jednotlivých
komponentov surového autoplášťa je dôležité pre ďalšiu technológiu spracovania autoplášťa z pohľadu takých
vnútorných vád, ako sú vzduchové bubliny a separácie v rôznych častiach autoplášťa, ktoré ovplyvňujú celkovú
spoľahlivosť a životnosť autoplášťa.
The technological process of raw tyre production is
closely connected with the utilization of tyre building
drum where it is also necessary to wind the given
constituent parts of tyre around its bead plies and then,
the given constituent parts must be forced-in or pressedin mutually in the area which is determined by bead ply
and constituent part which is called crown of tyre. (The
crown can be found at sidewalls of tyre. It can be seen
in the fig. 1.
The mentioned procedure has been done by usage of
tyre building drums and there is also utilisation of the
specific or special mechanism which is called winding
mechanism. The tyre lever building drum, mentioned
hereinbefore, contains one winding mechanism in its
each one half. From the construction or the operating
aspect, the given and specific mechanism can be
designed in two different ways. The one construction
design consists of one (the first one) set of winding arms
at which the rollers are mounted and another
construction design consists of two (the first one and the
second one) sets of winding arms with mounted-in
rollers while these mounted-in rollers follow each other
in a stagger way.
Fig. 1 The technological process of mutual pressing-in of constituent
parts of tyre
Obr. 1 Technologický proces vzájomného zalisovania jednotlivých
komponentov autoplášťa
The dynamic analysis of the lever mechanism of
winding arms has been done by relaxation method in the
computer program Matlab. The basic position means
that the lever is in a horizontal plane. The operation
position means that the roller traces the profile of the
107
Počítačová simulace, výpočetní metody
Computer Simulation, Computing Methods
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
tyre. The shifting or movement of lever is performed in
the interval x <0-255 mm> and at the same time when
there is the shift or movement of the lever, there is also
the performance of another operation at which the lever
is turned in the direction from the axis y and moreover,
the shifting or movement of lever is given by specific
angle φ<0-30°>. The required stiffness for individual
flexible components or constituents as well as some of
the other required values were obtained in an
experimental way. The principle of relaxation can be
seen in the fig. 2 where there is the relaxation of
individual bodies which are subjected to motion
equation (1) and the given motion equation can be used
for determination of kinematic parameters or values for
movement of individual bodies in the system and in
addition, the appropriate reactions can be also found out
by this way.
flexible
constituents
Fig. 2 Relaxation of individual bodies
Obr. 2 Relaxácia jednotlivých telies
Motion equations:
Body 2:
m2 xT   Fi x   Ax  Bx  Fh  ( Fk1  Fk 2  Fk3 ) sin 
m2 yT   Fi y  Ay  By  G2  ( Fk1  Fk 2  Fk3 ) cos 
I A2   M i A  Bx (446. sin   58,5. cos  )  B y (446. cos   58,5. sin  ) 
 Fk1 .219,5  Fk 2 .169,5  Fk 3 .119,5
Fig. 3 The computational model of the mechanism
Obr. 3 Výpočtový model mechanizmu
(1)
Body 3:
m3 x   Fi x  Bx  N . cos   T . cos(90   )
m3 y   Fi y  By  G3  N . sin   T . sin(90   )
I B3   M i B  T .r  N .e
The fig. 3 shows the computational model of one of
winding
mechanism
which
was
used
for
accomplishment of dynamic analysis for the given
kinematic ratios of movement and corresponding input
values. The simulation of the movement of the
mentioned mechanism can be seen in the fig. 4.
Fig. 4 The simulation of the movement of mechanism
Obr. 4 Simulácia pohybu mechanizmu
The finite element method (FEM) was used for creation
of finite element model which is shown in the fig. 5.
The given model can be used for determination of
appropriate loading as well as distribution of stress for
individual constituents or components of mechanism.
108
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Počítačová simulace, výpočetní metody
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The fig. 6 and fig. 7 show the values of normal forces in
dependency on the position of the lever.
The tyre building drum for freight tyre w ith
22.5 inches of w heel car diam eter. The
norm al force of the first one set relating to
w inding arm s
Normal Force [N]
3000
2500
2000
1500
1000
500
0
0
50
100
150
200
250
Position of Lev er [mm]
The tyre building drum for freight tyre w ith
22.5 inches of w heel car diam eter. The
norm al force of the second one set relating
to w inding arm s
Fig. 5 The finite element model with the distribution of stress
in the lever
Obr. 5 Model na základe metódy konečných prvkov s pridaním
pákového napätia
Normal Force [N]
1400
The tyre building drum for passenger car tyre
w ith 14 inches of w heel car diam eter. The
norm al force of the second one set relating to
w inding arm s
1200
1000
800
600
400
200
0
65
Normal Force [N]
90
115
140
165
190
215
240
Position of Lev er [mm]
80
Fig. 7 The course of normal force in dependency on the position
of the lever
Obr. 7 Priebeh normálovej sily v závislosti od pozície páky
70
60
50
30
40
50
60
70
80
90
100
110
Acknowledgement
The work presented in this paper was supported by
VEGA grant No. 1/0530/11.
120
Position of Lev er [mm]
The tyre building drum for passenger car tyre
w ith 14 inches of w heel car diam eter. The
norm al force of the first one set relating to
w inding arm s
Literature
[1] AZAR, J.J. Matrix Structural Analysis, Pergamon Press, New
York, 1972
375
Normal Force [N]
90
[2] BATHE, K., J.: Finite element procedures in engineering
analysis. Englewod Cliffs 1982.
350
325
[3] BATHE, K.J., WILSON, E.L., PETERSON, F.E.: SAP-IV,
A Structural Analysis Program for Static and Dynamic Response
of Linear Systems, Berkeley, 1973
300
275
250
225
[4] TEPLÝ, B. Metóda konečných prvkov. VUT, 1990
200
0
25
50
75
100
125
150
Position of Lev er [mm]
[5] VAVRO, J., KOPECKÝ, M., SÁGA, M., FANDÁKOVÁ, M.
Nové prostriedky a metódy riešenia sústav tellies II, ISBN 809683337-9-0, Trenčín 2004
Fig. 6
The course of normal force in dependency on the position
of the lever
Obr. 6 Priebeh normálovej sily v závislosti od pozície páky
Review: prof. Dr. Ing. Milan Sága
prof. Ing. Milan Žmindák, PhD.
109
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ISSN 0018-8069
Numeric Analysis of the Eigenfrequencies of the Ductile Cast Iron with the
Spheroidal Shape of Graphite and Grey Cast Iron with the Lamellar Shape of
Graphite
Numerická analýza vlastných frekvencií tvárnej liatiny s guľôčkovým tvarom
grafitu a sivej liatiny s lupienkovým tvarom grafitu
prof. Ing, Ján Vavro, PhD., Ing. Ján Vavro, PhD., jr., Ing. Alena Vavrová, PhD., Ing. Petra Kováčiková,
Ing. Robert Vanc, Department of Material technologies and Environment, Faculty of Industrial Technologies,
University of Alexander Dubček in Trenčín, I. Krasku 1809/34, 020 01 Púchov, Slovakia
The given work is focused on the analysis of the eigenfrequencies and natural shapes as well as it is concerned with
stress distribution in the frequency area referring to the ductile cast iron with the spheroidal shape of
graphite(SGCI) and grey cast iron with the lamellar shape of graphite(LGCI). The analysis was made with help of
finite element method in the software system ADINA.v.8.6.2. On the basis of the real structure, the finite element
method was used for creation of the model which was subsequently used for calculation of the eigenfrquencies and
specific natural shapes which are closely connected with the vibrations of the structure of material. The he input
data for numeric analysis were obtained on the basis of evaluation of the structure by help of image analysis. The
numeric analysis proved that the graphetic particles in the matrix cause the concentration of the stress and the
extension of the given stress depends on the shape of the graphetic particles.
Práca sa zaoberá numerickou analýzou vlastných frekvencii a vlastných tvarov, ako aj rozložením zaťaženia vo
frekvenčnej oblasti u tvárnej liatiny s guľôčkovým tvarom grafitu a sivej liatiny s lupienkovým tvarom grafitu.
Analýza bola vykonaná metódou konečných prvkov v softvérovom prostredí ADINA.v. 8.6.2. V článku je stručne
popísaná štruktúra tvárnej liatiny s goľôčkovým tvarom grafitu a štruktúra sivej liatiny s lupienkovým tvarom
grafitu. Vstupné hodnoty pre numerickú analýzu metódou konečných prvkov sa získali z hodnotenia štruktúry
obrazovou analýzou. Na základe reálnej štruktúry materiálu bol vytvorený konečno-prvkový model, z ktorého sa
vypočítali vlastné frekvencie a vlastné tvary kmitania štruktúry materiálu. Z numerickej analýzy vyplýva, že
grafitické častice svojou existenciou v matrici spôsobujú koncentráciu napätia a veľkosť koncentrácie napätia bude
závisieť od tvaru grafitických častíc. Koncentrácia napätia sa zväčšuje nepravideľnosťou grafitickej častice.
Najpriaznivejšie rozdelenie je pri ovalite tvaru gule. Ukazuje sa tu nová oblasť využitia výpočtových prostriedkov
pre analýzu stavu štruktúry materiálu v oblasti frekvenčných, tlmiacich a napäťových.
The progress of the numeric processes is closely
concerned with the new possibilities and new
opportunities of materials engineering including
modelling of structures of materials and their
simulations for various types of loading. The process of
deformation is connected with the foreseeability and
understanding of microstructure properties because it is
really important for knowledge and specification of
defect formations of castings during the process of their
production or during the moulding processes [1, 2]. In
the recent years, the microstructure modelling and its
simulation has played quite important role because of
finding out of properties and suitability of usage of the
given material before its production.
The finite element method allows us to operate with
atypical parameters of microstructure. Nowadays, this
method is commonly used in the various scientific fields
and spheres. In addition, the most common usage can be
found
in
mechanics,
materials
engineering,
thermodynamics and biomechanics etc. [3, 4]. All types
of simulations reduce the given specific construction
process and there is also opportunity to test or investigate
the model at various working conditions and loadings.
Structure of cast iron with the spheroidal
shape of graphite (SGCI)
The structure of the basic metallic microstructure of
SGCI influences many factors. Two of these many
factors are very important because they are connected
with the differences of characteristics of austenite
transformation which is carried out at unchanged
conditions. Influence of chemical composition and
influence of cooling speed are the given and important
two factors which are mentioned hereinbefore.
According to this mentioned fact, there can be the
occurrence of ferritic, ferritic-pearlitic or pearlitic
structure for cast irons fig. 1.
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Fig. 1 Microstructure of SGCI , etched by Nital, zoomed 100 x
Obr. 1 Mikroštruktúra tvárnej liatiny s guľôčkovým grafitom,
naleptaná Nitalom, zv. 100 x
Moreover, structure as well as properties of SGCI can
be influenced by alloying process and thermal treatment
in some particular limiting cases. SGCI belongs to iron
carbon alloys and there are also other elements. Its
structure consists of basic metallic substance – matrix
and the graphite can be found in this matrix. This
graphite has a specific shape. It is sort of the regular
granular grains. From the aspect of the shapes, this
shape of graphite has the least notch or impact effect.
Doe to this fact, SGCI has very good mechanical
properties and therefore SGCI can be included among
the most common materials which are suitable for
manufacturing of castings [5, 6].
Structure of the grey cast iron with the
lamellar shape of graphite (LGCI)
The grey cast iron with the lamellar shape of graphite
(LGCI) is one of the most used cast irons. When there is
the fracture of LGCI, the colour of the area of fracture is
grey and therefore, this cast iron is also commonly
called the grey cast iron. LGCI contains from 2.5 to
3.5 wt. % of carbon as well as the silicon, the content of
which is up to 3 wt. %. This grey cast iron is the
cheapest cast metal and because of its properties, it is
also one of the most used cast materials. The lamellar
graphite is contained in its structure, while the given
structure consists of the pearlitic, pearlitic-ferritic or
ferritic metallic matrix together with the lamellar
graphite (fig. 2).
Počítačová simulace, výpočetní metody
Computer Simulation, Computing Methods
that is identical with real state of cast iron. The image
analyse was used for evaluation of number of graphetic
particles, content of graphite and shape of graphite (via
shape factor) and the content of ferrite in basic material
was evaluated for etched samples. Shape factor K
represents the circularity and if the value equals to
number one, it means that it is circle but if the value
equals to number zero, it means that it is straight line.
According to the mentioned facts, the circularity can be
calculated by help of equation:
K
4π A
P2
(1)
where A is an area of the particle and P is
a circumference of particles. The shape factor can
acquire values:
- for lamellar graphite: K < 0.27;
- for vermicular graphite: K = 0.27 ÷ 0.60;
- for spheroidal graphite: K > 0.65 [7].
a)
b)
Fig. 3 Microstructure: a) SGCI b) LGCI at zoom 100 x
Obr. 3 Mikroštruktúra: a) SGCI – tvárna liatina s guľočkovým
tvarom grafitu; b) LGCI – sivá liatina s lupienkovým tvarom
grafitu pri zv. 100 x
Selection of type of finite elements and size
of element
The designed model of SGCI and LGCI material
structure was concerned with doing of sensitivity
analysis tab. 1 relating to change of intensity of stress
distribution around the graphetic particles. The
graphetic particles are designed as cavities without
finite element mesh. On the base of the sensitivity
analysis, the determined size of elements was
0.0005 mm. This mentioned size of elements ensures
good uniformity and accuracy of resolution and the
error is not higher than 2.5%. Linear triangular elements
(fig. 4) are used for solution. Geometric model was
made up for 10% graphetic proportion in structure, the
number of particles was 200 ks/mm2 and size was
chosen in the interval from 30 μm to 60 μm.
a)
b)
Fig. 2 Microstructure of grey cast iron:, a) etched by Nital, zoom
100 x; b) etched by Nital, zoom 500 x
Obr. 2 Mikroštruktúra sivej liatiny:, a- lept. Nital, zv. 100 x; b) lept.
Nital, zv. 500 x
Evaluation of the microstructure by image
analysis
Image analysis of the microstructure (SGCI and LGCI Fig. 4 The types of elements for 2-D areas
fig. 3) is carried out for the purpose of obtaining of Obr. 4 Typy elementov pre 2-D oblasti
basic data which are needed for formation of the model
111
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ISSN 0018-8069
Tab. 1 Sensitivity analysis toward the size of elements
Tab. 1 Analýza citlivosti voči veľkosti zŕn
Size of
elements
0.01
σyy
σzz
1.215
0.009
1.209
0.008
0.007
σyz
σHMH
0.0516
0.012
1.042
0.0461
0.0033
1.038
1.208
0.0464
0.0055
1.036
1.225
0.0371
0.0185
1.059
0.006
1.489
0.146
0.048
1.211
0.005
1.501
0.16
0.028
1.206
0.004
1.780
0.246
0.0011
1.388
0.003
1.947
0.271
0.0060
1.510
0.002
2.385
0.384
0.013
1.819
0.001
2.800
0.310
0.0069
2.247
0.0009
2.780
0.285
0.164
2.270
0.0008
2.904
0.266
0.048
2.369
0.0007
2.861
0.237
0.0821
2.358
0.0006
2.925
0.215
0.0864
2.436
0.0005
2.931
0.180
0.0089
2.467
0.0004
2.918
0.146
0.013
2.479
From the point of view of materials engineering, the
preparation of geometric model is closely connected
with the utilization of characteristic data of SGCI (for
purpose of definition of input data). The mentioned
characteristic data were obtained on the base of visual
image analysis of the experimental material:
 number of graphetic grains for 1 mm2: 100 ÷ 300 units,
 average diameter of graphetic grain: 0.01 ÷ 0.08 mm,
 area proportion of graphite in the structure: 4 ÷ 12 %.
0.0003
2.916
0.107
0.007
2.507
Where σyy – stress in the direction of loading, [MPa]; σzz – stress which
is perpendicular to direction of loading, [MPa]; σyz – shear stress,
[MPa];σHMH – equivalent stress with reference to HMH theory, [MPa]
Geometric model of SGCI and LGCI
The shape of the graphetic particle has a significant
influence on size of eigenfrequences as well as there is
the influence on state of surrounding stress. If we want
to evaluate the quality of graphetic particle, we have to
determine some geometric characterizations which
describe the mentioned particle. The given
determination is also closely connected with the method
of measurement of these characterizations [8]. The
precise description of boundary relating to graphetic
particles can only be obtained during the process of
evaluation of results of FEM analysis. This partial
restriction is caused by impossibility to obtain any other
description of boundary. It can be done only by help of
mesh of finite elements.
The first phase of preparation of models is concerned
with determination of basic model properties. Matrix
could be considered to be a homogenous structure with
the linear dependency deformation – stress. Graphetic
particle could be the cavity which could be designed in
a specific way and it means that the mesh of the finite
elements would not be created in the area of this cavity.
This type relating to modelling of graphetic particles is
possible because of their properties: low tension and
frequent decohesion from matrix. Calculation as well as
statistic evaluation of results could be done only after
generation of large number of geometric models and in
this case, the generation should be done for
approximately 750 models. During the solving of given
task, we decided to create the automatic model
generator which operates on the base of generating of
random numbers [8].
The portion of graphetic skeleton depends on
crystallization rate (growth is subjected to diffusion of
carbon) and amount (proportion and number) of eutectic
units especially depends on number of nuclei in molten
mass (treating agents). These two mentioned factors
have significant influence therefore they are the
determinative factors for area proportion of graphite in
the structure. On the base of the given mentioned fact
hereinbefore, we generated the mesh from points which
were connected together and these points can be also
understood as representatives of potential centres of
graphetic particles. The auxiliary parameter was used
for their generation. This auxiliary factor specifies
minimal distance between particular graphetic particles.
For determination of the given diameter of graphetic
particle, we have to generate the auxiliary mesh of
points with the sufficient density, for example 100 x 100
points and then we can specify the number of points
which belong to individual centres of graphetic
particles. The mentioned process is the principle for
determination of area proportion for graphite and it is in
relation to the individual graphetic particles with the
respect to number and size. According to this fact, it is
possible to determine the diameter of the individual
graphetic particles. This type of change relating to
generation of models is connected with the elimination
of many problems including size, distribution and
number of graphetic particles. On the other side, the
diameter of particle can be understood as function of
mutual position of graphetic particles and it means that
there is not any possibility of occurrence of such
particles which would be disproportional from the
aspect of “largeness” or size and it also means that there
is the elimination of occurrence of too “small” particles
of spheroidal graphite. According to these properties,
the algorithm was supplemented by control of scattering
relating to size of graphetic particles. In case that the
given scattering runs over the determined values, the
selection relating to centres of graphetic particles is not
suitable for any other analysis and therefore these
unsuitable particles are not utilized for any other
analysis. The algorithm which was made in this way
fulfils all qualitative as well as quantitative parameters.
This given algorithm is also supplemented by ability of
shape variation for graphetic particles.
Software solution of algorithm is connected with
software Octave (share-ware version of Matlab) which
is able to generate input file for software GID where
spline curves are used for solutions in the area relating
to individual graphetic particles. End points of spline
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Počítačová simulace, výpočetní metody
Computer Simulation, Computing Methods
are identical but they are not continuous. The post
editing of spline curves can help us to obtain continuous
areas which represent graphetic particles. Subtraction of
the area for graphetic particles from the whole area of
investigated model is used for obtaining of resultant
geometric model without graphetic particles whereby
the boundaries of the model are continuous. This
obtained geometric model is saved in IGES format.
FEM in software ADINA is used for consecutive
analysis because this software allows downloading of
geometric data in IGES format. The results of generated
“graphetic particles” in software Octave can be found in
the fig. 5 and fig. 7. Arbitrary structure of material can
be represented by graphetic particles which are
randomly generated for creation of the model of various
size and shape.
Fig. 7 The process of generation of shapes of graphetic particles in
the analyzed areas of LGCI
Obr. 7 Proces tvorby tvarov grafitických častíc v analyzovaných
oblastiach sivej liatiny s lupienkovým tvarom grafitu
Fig. 8 The first shape of the eigenfrequency of SGCI
Obr. 8 Prvý tvar vlastnej frekvencie liatiny s guľôčkovým
tvarom grafitu
Fig. 5 The process of generation
Fig. 6 The generated mesh of
of shapes of graphetic particles
finite elements for more particles
in the analyzed areas of SGCI
Obr. 6 Vytvorená sieť konečných
Obr. 5 Proces tvorby tvarov
prvkov pre viaceré častice
grafitických častíc pre analyzované
oblasti tvárnej liatiny s guľôčkovým grafitom
As it has been said, graphetic particle can be understood
as a cavity in the structure of material with its various
size and shape. The whole problem is based on the
solution of the two-dimensional system. The limiting
conditions can be represented by taking of degrees of
freedom from the whole circumference relating to
model. The linear material model with the respect to
Young’s modulus, also known as tensile modulus E =
2.1.105 [MPa], Poisson’s ratio ν = 0.3 and mass density
ρ = 7850 [kg/m3] is used. The area of the resolving is
determined for one or more graphetic particles with the
size 0.5 0.5 mm, while graphetic particles are
generated in the area 0.45  0.45 mm. This chosen ratio
for area of resolution, where graphetic particles are
generated, means elimination of influence including
eigenfrequences which can be connected with the
closeness of boundary for area of resolution. The
generated mesh of finite elements is shown in the fig. 6.
Fig. 9
The first shape of eigenfrequency of SGCI with the respect to
distribution of stress around graphetic particles
Obr. 9 Prvý tvar vlastnej frekvencie liatiny s guľôčkovým tvarom
grafitu s ohľadom koncentrácie napätia okolo grafitických
častíc
Fig. 10 The first shape of the eigenfrequency of LGCI
Obr. 10 Prvý tvar vlastnej frekvencie liatiny s lupienkovým
tvarom grafitu
The Fig. 8 represent only the first shape of
eigenfrequency SGCI but Fig. 9 represent the first shape
of eigenfrequency with the respect to distribution of
stress around the graphetic particles.
Fig. 11 The first shape of eigenfrequency LGCI with the respect to
distribution of stress around graphetic particles
Obr. 11 Prvý tvar vlastnej frekvencie liatiny s guľôčkovým tvarom
grafitu s ohľadom koncentrácie napätia okolo grafitických
častíc
The fig. 10 represents only the first shape of
eigenfrequency of LGCI but fig. 11 represents the first
113
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ISSN 0018-8069
shape of eigenfrequency with the respect to distribution
of stress around the graphetic particles.
Conclusions
Existence of graphetic particles in matrix causes
concentration of stress and the intensity of the given
stress depends on the shape of graphetic particles. The
concentration of stress is increased by irregularity of
graphetic particle. The most perfect distribution is found
out for spheroidal shape relating to sphere. The
mentioned process relating to investigation can be used
for any other types of cast structures. The results which
are obtained on the base of analyses represent the first
information about loading and properties of the whole
system or structure of material and the most important
fact is that this given information is known.
Acknowledgement
The work presented in this paper was supported by
VEGA grant No. 1/0530/11.
Literature
[1] SHEN, G., ROLLINS, J., FURRER, D. Microstructure Modeling
of Forged Waspaloy Discs. Superalloys 1996, KISSINGER, R.D.
et al. (Ed.). TMS, 1996, p. 613–620
[2] DOBRZAŃSKI, L.A., ŚLIWA, A., TAŃSKI, T. Finite Element
Method application for modelling of mechanical properties. In
Computational Materials Science and Surface Engineering.2009,
vol. 1, p. 25–28 [cit.2010-9-3]
[3] DUARTE, C.A., BABUŠKA, I., ODEN, J.T. Generalized finite
element methods for three-dimensional structural mechanics
problems. In Computers & Structures [online]. 2000, vol. 77, p.
215–232 [cit. 2010-9-3]
[4] CHAWLA, N., GANESH, V.V., WUNSCH, B. Threedimensional (3D) microstructure visualization and finite element
modeling of the mechanical behavior of SiC particle reinforced
aluminum composites. In Scripta Materialia 2004, vol. 51, p.
161–165 [cit. 2010-9-3]
[5] DEKAZINCZY, F. Effect of Small Defects on the Fatigue
Properties of Medium-Strength Cast Steel, Iron Steel Inst., 208,
1970, p.851-855
[6] MURAKAMI, Y. Metal Fatigue : Effcts of Small Defects and
Nonmetalic Inclusions, First edition, Elsevier Science, 2002
[7] NELDER, J.A., MEAD, R. A Simplex Method for Function
Minimization, Computer Journal, 7, 1965, p.308-313
[8] HANDRIK, M. Algoritmizácia modelovania stavu napätosti
v mikroštruktúra LGG liatin, DP, ŽU v Žiline, 2008
Review: prof. Dr. Ing. Milan Sága
prof. Ing. Milan Žmindák, PhD.
_____________________________________________________________________________________________
Užití hliníku se stále rozšiřuje
http://www.umformtechnikmagazin.de/umformtechnik-fachartikel/vorteile-von-aluminium-nutzen_21555_de/
Hliník je nejrozšířenější kov na zemi, s jeho využíváním se začalo až velmi pozdě. Byl totiž izolován až
v r. 1825 a s jeho průmyslovým využíváním se začalo ve větší míře až ve 20. století. Jeho spotřeba však
neustále roste a dnes je to po železe nejčastěji používaný kov. Ročně se vyrobí okolo 45 mil. t hliníku a
téměř třetina se vyrobí v Číně. Polovina z vyrobeného hliníku se spotřebuje v potravinářském průmyslu a
to na plechovky pro nápoje a na fólie pro balení potravin. Na druhém místě ve spotřebě hliníku je
stavebnictví, kde se uplatňují hliníkové lišty na oknech a dveřích, krytina na střechách a na fasádách a
další produkty.
Nejčastěji se při zpracování hliníku používá válcování. V leteckém průmyslu i v mnohých dalších
odvětvích se mnoho součástí vyrábí z tyčí třískovým obráběním, i když přitom je ztráta kovu velká.
V široké míře se uplatňuje kování a další metody tváření, což jsou beztřískové technologie. Používá se
tváření za tepla i za studena. Některé postupy tváření za studena jsou vysoce produktivní, umožňují
výrobu až 300 součástek za minutu. Výroba součástek tvářením za studena často umožňuje ušetřit
několik operací. Pokud se použijí leštěné nástroje, dosahuje se drsnost povrchu 0,04 až 0,08 Ra. Navíc
mají vyrobené součástky ve struktuře příznivý průběh vláken.
LJ
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Počítačová simulace, výpočetní metody
Computer Simulation, Computing Methods
Some Remarks on Carleman's Inequality
Niekoľko poznámok na Carlemanovu nerovnosť
doc. RNDr. Ladislav Matejíčka, CSc., Faculty of Industrial Technologies, University of Alexander Dubček in
Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia
In this paper, we give a method how to get sharpened versions of Carleman's inequality of a certain type. We obtain
a class of refined Carleman's inequalities. An open problem is proposed.
Carlemanova nerovnosť je veľmi známa nerovnosť. Má široké použitie a stále je predmetom záujmu mnohých
matematikov. V tejto práci je zostrojená metóda ako vylepšiť Carlemanovu nerovnosť istého typu a zároveň sú
uvedené niektoré príklady takýchto vylepšených Carlemanových nerovností. V práci je predložený istý otvorený
problém.
,
b1  1 , b 2  1 , b3  1 , b 4  73
2
24
48
5760
, b  1945
b5  11
1280 6
580608
The following Carleman's inequality is well known: Let
a n n1 be a sequence such that a n  0 , n  N and

a
n 1
  then, we have
n

 (a ...a
1
n
n 1
1
n
by Xiaojing Yang (see [8]) with
6


k
(a 1 ...a n )  e 1  
 an

k 
n 1
n 1 
k 1 (1  2n ) 

where a n n 1 satisfy a certain recursion formula,
)  e a n , where the coefficient e is
n 1
the best possible. Though the coefficient e is optimal,
we can decrease its weight coefficient with the
arithmetic-geometric mean inequality (see [10])

1

n
(
a
...
a
)

e
1   a n .


1
n
n
n 1
n 1 
2

 1 
e a
(a 1 ...a n )  e 1 

n
n 
n 1
n 1 




1

 2

2
1


 
 
1
1 
 a n   1 
 a
(a 1 ...a n ) n  e 1 

1
6  n where
n 1
n 1 
n 1 
n 

 n 
5
5


by Xie and Zhong (see [9]) with

 (a ...a
1
n 1
n
1
n

0    1 2 e,
0    1 ln 2  1, e  21  e.
(1  1 n) n  e , n  N .
Many of the refinements are in the following form:
and with the better approximation
(1  1 n) n  e(1  (1 n)) , n  N
6

bk 
(a 1 ...a n )  e 1  
 an

k 
n 1
n 1 
k 1 (1  n ) 

1
n
For more details about the Carleman's inequality, we
refer to ([1]). A basic tool in mentioned papers is a
refinement of the elementary inequality

6


)  e  1 
 an
12n  11 
n 1 
1
n
 
1  
n
(a 1 ...a n )  e 
an


1
n 1
n 1 
1  
n


by Yan Ping and Sun Guozheng (see [7]) with
1

and with
1

1 

n
(
a
...
a
)

e
1 
 an


1
n
2n  2 
n 1
n 1 

1
n

The Carleman's inequality has been improved by many
authors, for example: by Yang Bicheng and L. Debnath
(see [3]) with


by Bao-Quan Yuan (see [10])
with
n
1

1
n



where
( x ) , x  0,1  is a suitable non-negative
continuous function such that ( x )  0 , x  (0,1) .
where
In this paper we show how to improve such
inequalities.
115
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ISSN 0018-8069
Počítačová simulace, výpočetní metody
Computer Simulation, Computing Methods
Main Results
Lemma 2.1
Let ( x ) , x 
that
1 

 1  
e1  
  1 

 
1  l 
1  l  


 
 1 
ep 
 
1 l 
0,1  be a continuous function such
1 l
(12)
,
1
(1  x ) x  e(1  ( x )) for x  (0,1 k ) , k   N , (1)
i
 

1  1
e
1



1



  

 



 i   i 
   min  
; i  1,..., l  , p(1 i)  0, (13)
1


ep 


i





j

 1
 1
if k  1 then 1    e1     for


j

 j 

j  1,..., k  ,



(2)
Proof. Put
(0)  0 , ( x )  0 , ( x ) is a continuous
function for
1
x  (0,1 k ) ,
e1  x   1  x x
for x  (0,1 l ) . Since
h( x ) 
px 
(3)
h( x )  0 for x  (0,1 l ) we have
1


if k  1 then    0 for j  1,..., k  1. (4)
 j
Let p(x), x  0,1  be a continuous function such
1 l 

1 
 1  
e1   
  1 
 
 
1 l   1 l 


 
 1 
ep
 
1 l 
that p(0) = 0, p(x) > 0, p( x ) is continuous function



x  (0,1 l ) , l  N , l  k
if there is m  N ,

(5)
1
m  l such that    0
m
1
0
m
1

if l* > 1 then p   0 for j  1,..., l  1
j
 
then p



 e(1  ( x ))  (1  x )
lim 
x 1 l
ep( x )


Then there is


  0.


1
(6)
(7)
i
 

 1  1
e
1



1









i


 i  
  min  
; i  1,..., l  , p(1 i)  0,
1


ep 


i



(9)



and a 0  min  ,  . Then
a 0 is the best possible
and

1 

n
1

1
 1 
  e1     a 0 p   for n  N .
n
n
 n 

The proof is complete.
Lemma 2.2
Let ( x ) ,
that
a 0  0 such that
n
1


1
 1 
1    e1     a 0 p   for n  N (10)
n

n
 n 

a 0 is the best constant and a 0  min ,   where (11)
x  0,1  be a continuous function such
1
x
(1  x )  e(1  ( x )) for x  (0,1 k ) ,
k  N ,
j
(14)

 1
 1
k   1 then 1    e1     for
j

 j 

j  1,..., k   1,
(15)

( x ) is continuous function for x  (0,1 k ) , (17)
if
(0)  0 , ( x )  0 for x  (0,1 k ) ,

e1   x   1  x  x
,
ep x 

for x  (0,1 l  1  . Put
1

 1
1 
 e ( x)  (1  x) x  2 ln(1  x) 
  p ( x) 

x( x  1)  
x

1


 e(1   ( x))  (1  x) x  p( x)  0 , x  (0,1 l ) (8)




1
x

(16)
116
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ISSN 0018-8069
( x )  0 for x  (0,1 k )
(18)
1
k   1 then    0 for j  1,..., k   1. (19)
 j
Let p(x), x  0,1  be a continuous function such
if
1


 e1   x   1  x  x 
  inf 
,
0 x 1 /( m 1)
ep x 





that
(20)
x  (0, 1 l) , l  k 
p( x )  0 , p( x ) is a continuous function for
(21)
x  (0,1 l)
1
if there is m  N , m  l such that    0
m
1
(22)
then p   0
m
1
if l > 1 then p   0 for j  1,..., l  1
(23)
 j
p(0) = 0, p(x) > 0,
there is m  N ,
and
i
 

1  1
e

1




1





 




 i   i 
   min  
; i  1,..., m  1, p(1 / i)  0
1




ep 


i




.
It implies a0  min
such that
(24)
The proof is complete.
Lemma 2.3 For n  N , the inequality
n
1


1
 1 
1    e1     a 0 p   for n  N . (25)
n

n
 n 

2
10


1
4


 1
 1 
e
e


1    e 1 
1  
n

n2  n 
 n




10
holds, where the constant 4 
is the best possible.
e
Proof. Put  (x)  (1  2 / e) x ,
p(x)  x 2 (1  x) for x  0, l  . From p( x)  0
for x  (0,1 / 3) and Lemma 2, we have there is the
best  0  0 such that
n
a 0 is the best constant and a0  min   ,    where
(26)

 e1   x   1  x 

0 x 1 /( m 1)
ep x 


inf

,   is the best constant
n
m
 

1


1
 1 
1    e1     a 0 p  
n

n
 n 

for n  N .
m  l such that:

1
 1  
e1       1    0.
 m   m 

Then there is a 0  0 such that

1
x


,


(27)
i
 

1  1
e

1




1

  

 



 i   i 
   min  
; i  1,..., m  1, p(1 / i)  0
1




ep 


i




1
(1  x) x  e(1   ( x))   0 p( x)
(28)
for x  0,1 3  . We show that  (x) and p(x)
fulfil the assumption (8) of Lemma 2.1. (8) is
equivalent to
Proof. Put
h ( x)  e1   x   ep( x)  1  x  x for
x  0, l ,   0 ,   R . The assumption (24)
implies there is a1  0 such that
1
1
{2e  4) x 2  (4e  2) x  2e  (1  x) x 
1  x
1  3x 2

ln(1  x) 
1 x
 x

1
 1 
1 
e1       e 1 p   1    0.
 m 
m  m

From h1 ( x)  0 for x  (0,1 m) and h1 (0)  0 ,
m
 .
.

(29)
 x2 
(1  x) x  e
 we
 2x  2 
1
Using the inequality
obtain
h1 (1 / m)  0 , we have h1 ( x)  0 for
x  0,1 / m , . Denote
{4e  8) x5  (3e  4) x 4  (8  2e) x3  (4  e) x 2 
117
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Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
2ex  e(2  x  2 x 2  x3 ) ln(1  x).
Using the inequality
ln(1  x)  x 
n
 m1
1
1 
 1
1    j p j    p m   
1


e



 n
n
 n  
j 1

for n  N .
(30)
x 2 x3
we get

2
3
For k = 1 the best constant is
2
 0, 264241117 .
e
2ex  (25e  48) x  (4e  24) x  (48  e) x 
1  1 
24  6e  0
For k = 2 the best constants are
4
3
2
(31)
2
 0, 264241117 ,
e
10
 2  4   0, 321205588.
e
1  1 
Denote
g ( x)  2ex  (25e  48) x  (4e  24) x 
(48  e) x  24  6e  0 for x  0,1  .
It is evident that g ( x)  7e . It implies (31) holds and
4
3
2
For k = 3 the best constants are
so (8) holds. It is easy to see, that the other assumptions
of Lemma 1 are fulfilled.
Lemma 2.1 implies
2
 0, 264241117 ,
e
10
 2  4   0, 321205588. ,
e
702
 3  270 
 11, 7486323 23.
e
1  1 
2

 1  1  1 
1       1  
10
 2  e  2 
0  
 4
e
1
p 
2
Lemma 2.5 Let p k x   x
The prof is complete.
0
where
a
j 1
j



x  0,1 , k  N k  1 and p1 ( x)  x. Then
(a)
pk ( x)  0. for x  (0,1 / k )
(b)
pk ( x)  0. for x  (0,1 /( k  2))
such that

n
k

1
 1
1    e1    i k 2 k  2
 n
i 1

n 2

for n  N
1
  j  x 
j 1
Lemma 2.4 Let. k  N . Then there exist positive
1 ,  2 ,...,  k
k 2  k  2 k 1
2

 1 1 
   

n 
j 1  j

k 1
Proof. We use the mathematical induction. It is evident
p2 ( x)  0. for x  (0,1 / 2) , p2 ( x)  0. for
x  (0,1 / 4) .Suppose that pj ( x)  0. for
that
 1 . The constants 1 ,  2 ,...,  k are
x  (0,1 / j ) , pj ( x)  0. for x  (0,1 /( j  2)) ,
the best possible.
Proof. It follows follows from Lemma 2.2 and Lemma
2.5.
j  2,..., k . It follows from
pk 1 ( x)  x k (1 / k  x) pk ( x) that
Remark 2.1. The constants 1 ,  2 ,...,  k are the best
pk 1 ( x)  (1, (k  1) x) pk ( x)  x k (1 / k  x) pk ( x)
possible constants in the following sense
  1  0 is the best possible constant such that
pk1 ( x)  x
and
k 2
(k  1  k (k  1) x) pk ( x)  2 x k 1 
(1  (k  1) x) pk ( x)  xk (1/ k  x) pk( x).

 1
 1 
1    e1  p1    , . n  N .
 n
 n 

If 1 ,  2 ,...,  i are the best possible constants such
n
pk 1 ( x)  0. for x  (0,1 /( k  1)) and
pk1 ( x)  0. for x  (0,1 /( k  3)) . Setting
 ( x)  0 for x  0,1 , in Lemma 2.1 or Lemma
It implies
that
2.2 we can obtain new refinements of the elementary
inequality
n
i

 1
 1 
1    e1    j p j   
 n
 n 
j 1

for n  N for all i such that i  m  k , i, m  N
then    m 0 is the best possible constant such that
n
 1
1    e , n  N
 n
1 1 1
Lemma 2.6 For x  1 and  
   we
ln 2  2 e 
have
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2
1   1   
 e   1  1  1 ,



p1
ln 2  2 e 

 1
 1   1 
1    e1   1   ln 1    .
x
x 
x 



1 1 1
The constant
   is the best possible.
ln 2  2 e 
x
The prof is complete.
Lemma 2.7 Let a n n 1 be a sequence such that
Proof.
Put  ( x)  0 ;

p( x)  ( x  1) ln(1  x) for
x  0,1  . From p( x)  0 for x  (0,1), and
Lemma 2.2, we have there is the best
1  x  x
1

a n  0 , n  N , k  N and  a n   , then, we
 0  0 such that
n 1
have
 e1   x   a0 px 
  e  2  1   1  
 a1...an n  e 1   1   ln1   an

x  0,1  .
We show that  (x) and p(x)fulfil the assumption (8) of
for
n 1
Lemma 2.1. (8) is equivalent to
1
1 x 2

 2 ln (1  x)  ln(1  x)  ln(1  x)  1 
x
 x

(32)
eln(1  x)  1 ´.
1  x
Using known inequalities
1  x  x
1
 x2 
 e
 , ln 1  x   x , x  0
 2x  2 
in (32) it is sufficient to show that
 x2 
2
2
2
e
 (1  x) ln (1  x)  ( x  x) ln(1  x)  x 
 2x  2 


exln(1  x)  1 .
n 1
 k 1
( x 2  3x  2) ln 2 (1  x)  ( x 3  x 2  2x) ln(1  x)  x 3 . (34)
Denote
h( x)  ( x 2  3x  2) ln 2 (1  x)  ( x 3  x 2  2x) ln(1  x)  x 3 ,
x  (0,1),
Differentiation yields
1
h( x) 
(2 x 2  5 x  3) ln 2 (1  x) 
1 x
3
2
(3x  3x  2 x  2) ln(1  x)  4 x3  4 x2  2 x) . (35)
Denote
g ( x)  (2 x 2  5x  3) ln 2 (1  x)  (3x3  3x 2  2 x  2) 
n 
n 
(a)
 i ik1 is given by
k
1
 

 e1    j p j x   1  x  x
j 1


 inf  
0 x 1 /( k 1)
ep k 1 x 






,



i
 k

 1    1 

e
1


p

1

   j j    

 i   i 
  j 1


 k 1  min 
; i  k  1, k  2, k  3 ,
1


ep k 1  


i




ln(1  x)  4 x3  4 x 2  2 x



ak 1  min  k 1 ,  k 1 ,
Differentiation yields
g ( x) 
 e ln 4 

1
n
possible,
(33)
Overwriting (33) we obtain

2
10


4
 1

1
e
e 1   a (b)



a
...
a

e
1


 n


1
n
n
n2  n 
n 1
n 1 




 k



1

1 k 1  1 1  
a1...an n  e 1   i k 2 k 2     an (c)

n 
n 1
n 1 
i 1
j 1  j
n 2


where the constants e, 1 ,  2 ,...,  k are the best

1
x

1
Proof. It follows from Lemma 2.3, Lemma 2.4, Lemma
1
((4 x 2  9 x  5) ln 2 (1  x) 
1 x
2.6 and the formula (2.7)(see [10]).
It is easy to see that the best possible constants
1 ,  2 ,  3 in Remark 2.1 are solutions of the
(9 x3  11x 2  6 x  8) ln(1  x)  15x3  32 x 2  8x .
equations.
From
5x2 + 17x + 12 > 0 for
x  (0, 1) and ln(1 + x) < x we
have g(x) < 0 , x  (0, 1) . Since g(0) = 0 we get
i
i

 1
 1  

1


e
1


p


  , i  1,2,3.

j
j

 i
 i 
j

1

g(x) < 0, x . (0, 1). It implies h(x) < 0 and so the
assumption (8) of Lemma 2.1 holds. It is easy to see
that the other assumptions of Lemma 2.1 are fulfilled.
Lemma 2.1 implies
Hence we propose the following open problem:
Open Problem.
119
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Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Let k  N ,  i i 1 be a sequence the best possible
constants from Lemma 7. Then we have
[2] H. ALZER, A refinement of Carlemans inequality, Journal.
Approx.Theory, 95 , (1998), 497-499.
k
[3] Y. BICHENG, On Hardys Inequality, J. Math. Anal. Appl., 234,
2, (1999), 717{722, http://www.idealibrary.com.
2
1  1  ,
e
i 1
k
1 
 1  1
1   j p j 
  1 

 i 1 e  i 1
j 1
 i 1 
; i  1,..., k  1
 1 
pi 1 

 i 1
if k  1,
[4] . BICHENG and L. DEBNATH, Some inequalities involving the
constant e and an application to Carlemans inequality, J. Math.
Anal. Appl., 223, 1, (1998), 347{353.
[5] Jian-Lin Li, Notes on an Inequality Involving the Constant e, J.
Math.Anal.
Appl.,
250,
2,
(2000),
722{725,
http://www.idealibrary.com.
[6] HAIPING LIU and LING ZHU, New Strengthened Carlemans
Inequality and Hardys Inequality, Journal of Inequalities and
Applications, 2007, Article ID 84104, 7 pages.
where
p1 x   x, p m x   x
m 2  m  2 m 1
2
1



[7] J. PECARIC and K. B. STOLARSKY, Carlemans inequality:
history and new generalizations, Aequationes Math. , 61, (2001),
49-62.
  j  x 
j 1
[8] Y. PING and S. GUOZHENG, A strengthened Carleman
inequality, J. Math.Anal. Appl., 240, (1999), 290-293.
x  0,1 , m  N .
[9] XIAOJING YAN, On Approximations for Constant e and Their
Applications, J. Math. Anal. Appl., 262, (2001), 651-659,
http://www.idealibrary.com.
Conclusions
[10] Z. XIE and Y. ZHONG, A best approximation for constant e and
an improvement to Hardys inequality, J. Math. Anal. Appl., 252
(2000), 994998.
In this paper we proved some new Carleman's
inequalities.
[11] BAO-QUAN YUAN, ReŻnements of Carlemans inequality,
Journal of Inequalities in Pure and Applied Mathematics, 2,
Issue 2, Article 21, (2001), http://jipam.vu.edu.au/.
Acknowledgement
The work presented in this paper was supported by
VEGA grant No. 1/0530/11.
Review: RNDr. Klement Hrkota, PhD.
Ing. Lenka Rybičková
Literature
[1] P. CERONE and C.T. LENARD; On Integral Forms of
Generalised Mathieu Series, Journal of Inequalities in Pure and
Applied Mathematics 4, (2003), no. 5, Article 100.
_____________________________________________________________________________________________
Disky z kovaných hliníkových slitin i pro nákladní auta
http://forgingmagazine.com/materialsmro/study-forged-aluminum-wheels-cut-co2-commercial-vehicles?NL=FORG01&Issue=FORG-01_20121003
Americká firma Alcoa Wheel & Transportation Products zveřejnila studii zaměřenou na hodnocení disků
pro nákladní vozy z kovaných slitin hliníku. Je v ní uvedeno, že americký kamion s 18 kovanými disky z
hliníkové slitiny za dobu své životnosti vyprodukuje o 16,3 t méně kysličníku uhličitého, evropský kamion
s 12 hliníkovými koly vyprodukuje o 13,3 t těchto exhalací méně. Při výpočtu se uvažovalo s celým
výrobním a uživatelským cyklem. To znamená, že se do výpočtu zahrnuly exhalace vzniklé při výrobě
výchozí slitiny, při výrobě vlastního kola i při jeho recyklaci ve srovnání s dosavadním kolem, přičemž se
využívala nejnovější data, která jsou k dispozici. Na výrobu výchozí slitiny a tváření disku se spotřebuje
více energie, ovšem úspory vzniklé při provozu a recyklaci to vyváží.
LJ
120
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Computer Simulation, Computing Methods
Note On Open Problem of Infinite Series
Poznámka k jednému otvorenému problému nekonečných rad
doc. RNDr. Ladislav Matejíčka, CSc., Faculty of Industrial Technologies, University of Alexander Dubček in
Trenčín, I. Krasku 491/30, 020 01 Púchov, Slovakia

V práci sú nájdené uzavreté integrálne formuly pre nekonečné rady
 j exp(  j2 x ) ,
j1
a n n1 je postupnosť kladných reálnych čísel.

 exp( a
n
x ) , kde
n 1
Closed integral forms expressions posed as open problems in [1] for


 j exp(  j x ) and for  exp( a
2
j1
x ) where a n n 1 is positive sequence of real numbers, x>0 are given.

n
n 1
In the paper [1] "On Integral Forms of Generalised
Mathieu Series” authors posed the open problems: find
number t, i.e such integer [t] which fulfills [t] = t < [t]+
1, i   1 imaginary unit, R(p) real part of complex
number p.

a closed form expression for
a n n1
 exp( a
n
x ) where
n 1
is a positive sequence of real numbers, x > 0,
Main Results
authors mentioned another open problem: find a closed

form expression for
Lemma 2.1. Let x > 0. Then
 j exp(  j x ) , x > 0. By using
2
j1
Euleur's integral formula [3], Laplace transform we
obtain closed integral formulas of the expressions. We
denote N  1,2,3,..., [t] the whole part of real

 j exp(  j2 x) 
j1
 si
exp( x )
1
exp( pt)  exp( p)
1

  exp(  t 2 x )(1  2t 2 x )dpdt.



2x
2i 1 si p  1  exp( p) p 
Proof. We use Euleur's integral formula [3] page 148
n
n 1
n 1
j1
1
1
 f ( j) 
where f,
 f ( t )dt 
f  are continuous functions on < 1, n + 1 >, n  N . Put f ( t )  t exp( t 2 x )
for x > 0, then
If we make


n 1
j1
1
 j exp(  j2 x) 
2
 t exp( t x)dt 
n 1
 ( t  [t]  1) exp( t x)(1  2t x)dt.
2
1
lim in the equation we get
n 
 j exp(  j2 x) 
j1
 ( t  [t]  1)f ( t)dt,

exp( x )
  ( t  [ t ]  1) exp(  t 2 x )(1  2t 2 x )dt.
2x
1
Using Laplace transform of periodic function t - [t] - 1 we get
121
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Hutnické listy č.7/2012, roč. LXV
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1
L( t  [ t ]  1) 
1
1
exp( p)
exp( pt)( t  1)dt  2 
.

1  exp( p) 0
p
p(1  exp( p))
Inverse Laplace transformation implies
si
t  [t]  1 
1
exp( pt)  exp( p)
1
 dp.


2i si p  1  exp( p) p 
s  i
where s =R(p), and

 lim
s i
Lemma 2.2. Let x> 0,

 exp( a
n
s  ih
h 

. The proof is complete.
s ih
a n n1 be a positive sequence of real numbers such that
x ) be a convergent series. Let ( t ) be a continuous function with
n 1
n=1
continuous its derivative

exist
( t ) on  1, ) such that ( n)  a n for n  N . Let there

 exp( ( t )x )dt ,  ( t  [t ]  1) exp( ( t)x)( t)dt . Then
1
1


j 1
1
 exp(a j x)   exp( (t ) x)dt 
 s i
x
exp( pt )

2i 1 s i
p
 exp( p)
1

  exp(  (t ) x) (t )dpdt.
1

exp(
p
)
p

Proof. Proof is the same as in the previous lemma.
The two lemmas are answer on open problems posed in [1]: finding a closed

form expression for
 j exp(  j x ) , x>0 and finding a closed form expression for
2
j1

F(a )   exp( a j x ) , x > 0 where a n is a positive sequence.
j1
Acknowledgement
The work presented in this paper was supported by
VEGA grant No. 1/0530/11.
Literature
[1] P. CERONE and C.T. LENARD, On Integral Forms of
Generalised Mathieu Series, Journal of Inequalities in Pure and
Applied Mathematics 4, (2003), no. 5, Article 100.
[2] F. QI, An integral expression and some inequalities of Mathieu
type series, Rostock Math. Kolloq, (2003 p. 389 392).
[3] T. ŠALÁT, Nekonečné rady ACADEMIA nakladatelství
Československé akademie ved Praha, 1974.
Review: RNDr. Klement Hrkota, PhD.
Ing. Lenka Rybičková
122
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ISSN 0018-8069
Řízení jakosti
Duality Management
řízení jakosti
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The Experimental and Theoretical Analysis of the Defects in Tyres for Freight
Vehicles at the Dynamic Loading
Experimentálna a teoretická analýza vád pneumatík nákladných vozidiel pri
dynamickom zaťažení
prof. Ing, Ján Vavro, PhD., Ing. Ján Vavro, PhD., jr., Ing. Alena Vavrová, PhD., Ing. Petra Kováčiková,
Department of Material technologies and Environment, Faculty of Industrial Technologies, University of Alexander
Dubček in Trenčín, I. Krasku 1809/34, 020 01 Púchov, Slovakia
The paper deals with propagation of defects as well as separations in tyres which are under dynamic loading. Main
reason for detection of the separations extension is to recognize an influence of closed air, small bubbles in tyre and
it is mainly connected with its quality during its service in vehicle in the term of road safety. This analysis should
help designers to solve serious problems in relation to tyre casing while the solution includes the material selection
and determination whether the individual components proportions are suitable and applicable or even whether the
construction of tyre casing is suitable. The reason for detection of internal separations in tyre casing is to avoid
usage of those tyres, which already contain some internal separation propagated during the movement of vehicles.
This is closely connected with occurrence of tyre destruction and therefore, the main purpose of this analysis is to
prevent critical conditions and subsequent vehicle crash and human life menace. In the paper, there is the proposal
of the process of the measurement as well as evaluation by the method of the active factor experiment.
Článok sa zaoberá skúmaním šírenia vád a separácií u autoplášťov nákladných vozidiel pri dynamickom zaťažení.
Veľká pozornosť sa venuje vzniku rôznych defektov a chybám materiálu ako sú separácie, bubliny, uzavretý vzduch
a pod. a tiež súdržnosti medzi jednotlivými materiálmi, z ktorých sa pneumatika skladá. Zisťovanie chýb a separácií
v plášti sa môže robiť viacerými spôsobmi. Môžu byť použité deštruktívne alebo nedeštruktívne metódy pomocou
ktorých dokážeme odhaliť chyby u nových, protektorovaných a ojazdených pneumatík. V práci bola použitá
nedeštruktívna metóda testovania autoplášťa. Výsledkom merania bolo určenie pohybu vady v závislosti od
hodinového zaťaženia autoplášťa. Aktívny faktorový experiment bol realizovaný pri zmene troch faktorov a to:
rýchlosti, zaťaženia a času prevádzky, pri konštantnom tlaku pneumatiky. Skúmaním šírenia vád dostanú vývojoví
pracovníci prehľad o najlepšom variante a zároveň o miestach, kde vada vzniká, ktorým smerom sa šíri. Na základe
týchto poznatkov sa môžu ľahšie riešiť kritické oblasti plášťa a dá sa jednoznačne rozhodnúť, ktorý variant je
vhodný pre použitie vo výrobe.
The increase of safety on the roads leads to more
enhancements of the tyres. The producers make
enormous effort to develop and design the tyres with
respect to their high reliability, easy mounting and
handling, high service life as well as high wear
resistance and of course cost effectiveness. From the
aspect of tyre production, all the mentioned facts are
closely connected with the fact that the higher attention
must be paid to precise testing. The various tyre
parameters, hold-off of the specified velocity, applied
load, inflation and defects by the fatigue, speed or
working benchmarks have been the subject of
investigation because of the enhancement of the tyre
production. Many of the tests are done under the
laboratory conditions because they help to recognize
many of critical states. Moreover, the high attention
must be also paid to investigation of the various defects
formation, disruptions extension and material defect as
separation, bubbles, retired air and so on. The article
deals with the distribution and measurement of the
separations in various tyre parts at the dynamic
benchmarks with non-destructive laser interferometric
measurement.
123
Řízení jakosti
Duality Management
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Start
The number of the single factors varying in this plan is
five; starry item distance from the planned centre is
useful to choose because the factor levels are equally
distant from the centre of plane. Then the rotary centre
plan of the experiment arises. The dispersion forecast of
the regression equation is calculated from the specific
number of repeated measurements relating to centre
composition plan.  constant is calculated by help of the
rotary centre plan while equation  = 2k/4. In the case if
k = 3 factors,  is 1.682 and complete matrix planning
scheme for the rotary centre plan of the class II is in the
tab. 1.
Yes
Linear model creation
Full factor
experiment
Linear model adequacy
End
No
Nonlinear model creation of the second
place value
Yes
Nonlinear model
adequacy
Composition plan
No
End
Model place value increase
Fig. 1 Creation of the appropriate model
Obr. 1 Vytvorenie príslušného modelu
 H1  ( ,0,0) 

 H 2  (0, ,0) starry factor items
 H 3  (0,0, ) 
Creation of the appropriate model
The active factor experiment is one of the opportunities
how to obtain maximum information at minimum costs.
Creation of the appropriate model for describing
relevant parameter response can be described on the
basis of the two-stage experiment expressed by the
scheme in the fig. 1.
Experimental plan
Graphic scheme of the composition plan of class II for k
= 3 factors is in the fig. 2, where C (0,0,0) – is a centre
of plan and (-V1V1), (-V2V2), (-V3V3) is variation factor
interval x1, x2, x3.
Fig. 2 The scheme of the centre composition plan
Obr. 2 Schéma centrálneho kompozičného plánu
Tab. 1 Complete matrix planning scheme for the rotary centre plan of the class II
Tab.1 Úplná schéma matice pre rotačný centrálny kompozičný plán typu 2
Exper. no.
FACTOR VALUES IN NON-DIMENSIONAL COORDINATE SYSTEM
Exit value
i
x1
x2
x3
x1 x2
x1 x3
x2 x3
x12
x22
x32
Y
1
-1
-1
-1
1
1
1
1
1
1
y1
2
-1
-1
1
1
-1
-1
1
1
1
y2
3
-1
1
-1
-1
1
-1
1
1
1
y3
4
-1
1
1
-1
-1
1
1
1
1
y4
5
1
-1
-1
-1
-1
1
1
1
1
y5
6
1
-1
1
-1
1
-1
1
1
1
y6
7
1
1
-1
1
-1
-1
1
1
1
y7
8
1
1
1
1
1
1
1
1
1
y8
9
-1.682
0
0
0
0
0
2.82
0
0
y9
10
1.682
0
0
0
0
0
2.82
0
0
y10
11
0
-1.682
0
0
0
0
0
2.82
0
y11
12
0
1.682
0
0
0
0
0
2.82
0
y12
13
0
0
-1.682
0
0
0
0
0
2.82
y13
14
0
0
1.682
0
0
0
0
0
2.82
y14
15
0
0
0
0
0
0
0
0
0
y15
16
0
0
0
0
0
0
0
0
0
y16
17
0
0
0
0
0
0
0
0
0
y17
18
0
0
0
0
0
0
0
0
0
y18
19
0
0
0
0
0
0
0
0
0
y19
20
0
0
0
0
0
0
0
0
0
y20
124
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
We consider making experimental plan for the
following endurance mode:
different testing tyre velocities (from 40 km/hour to
80 km/hour) - factor x1
- different tyre loading (from 20 kN to 50 kN) factor x2
- different time of experimental distance (from
20 hour to 200 hour) - factor x3
The other factors we consider as constant values for
example tyre inflation 380 kPa, tyre temperature and so
on. Spotted exit value is the motion of the impurity in
dependency on factors change (x1), (x2) a (x3).
Řízení jakosti
Duality Management
typical arrangement for the tyre control where the simple
cycle for tyre is utilized to recognise the inclusion.
-
Fig. 7 Image of separation on monitor Fig. 8 Testing arrangement
Obr. 7 Zobrazenie separácie na
at the simple cycle
monitore
Obr. 8 Skúšobné usporiadanie
pri jednoduchom cykle
Regression equation in general state is for planned three
factors of experiment of the class II with individual
factors on three levels:
For observing propagation of the tyre separations, the
specific tyre was selected, in which as can be seen in
fig. 9, the separations in the site of shoulder as well as in
k
k
the crown area of tyre casing were revealed and The
2
y  b   b x   b x b x x b x x b x x
0
i i
ii i
12 1 2 13 1 3 23 2 3 testing analyser ITT-1 was used during the process of
i 1
i 1
(1) measurement. After 20 hours of the dynamic test we
registered only small changes in separations extension
The examples of the tyre separations
therefore we introduce only display after 200 hours of
determined by laser interferometric
the dynamic test (fig. 10)
measurement
As it is seen in these examples, the tyre separations or
disruptions can be detected in various places. Disruption
propagation or separation is stochastic and depends on
more factors while the statistic method of probability for
the dispersion analysis is the optimum selection for
investigation and evaluation.
Fig. 9 First measurement before the dynamic test
Obr. 9 Prvé meranie pred dynamickou skúškou
Fig. 3 Longitudinal separation
in the site between the first
and second buffer lining
Obr. 3 Pozdĺžna separácia
medzi prvým a druhým
nárazníkom
Fig. 4 Longitudinal separation
in side of shoulder where the
the first buffer lining ends
Obr. 4 Pozdĺžna separácia v
mieste ramene ukončenia prvého
nárazníka
Fig. 10 11th measurement after 200 hours of the dynamic test
Obr. 10 Jedenáste meranie po odbehnutí 200 hodín dynamickej skúšky
Conclusions
Fig. 5 Local separations in tyre
Fig. 6 Local separation in the
sidewall
bead area of the tyre
Obr. 5 Lokálne separácie v bočnici Obr. 6 Lokálna separácia v
plášťa
oblasti pätky plášťa
Process measurement on non-destructive analyser
As can be seen in the individual figures, the separations
on the tyre periphery are spread and connect each other.
On the figure 10, we can observe separations created
almost in the whole periphery. If you pay attention to
figure 10 scan 1, you ca recognise that separations in the
shoulder can be also seen in external part of the tyre.
The Separations in the crown of tyre casing were not
changed after 16000 km of its running. . After the
detection on the ITT-1 machine, we cut the tyre and
studied if there were any separations on the places
which we saw in the scans are really separations.
Non-destructive analyser enables us to recognize tyre
structure defects quickly and easily – it is connected with
closed separations (fig. 7), the propagation of which we
will observe by the dynamic test. The fig. 8 shows the
125
Řízení jakosti
Duality Management
Hutnické listy č.7/2012, roč. LXV
ISSN 0018-8069
Separations were really confirmed, small separations
were detected in both shoulders in area, where there was
the end of the buffer lining and it was observed for the
whole tyre periphery (fig. 11) and propagation of defect
in tyre at the dynamic loading is shown in fig. 12.
% of error surface
16
14
12
10
8
6
4
2
0
0
20
40
60
80
100
120
hour efficiency
Fig. 12 Propagation of defect in tyre at the dynamic loading
Obr. 12 Šírenie vady v pneumatike pri dynamickom zaťažení
Fig. 11 Image of tyre section after 200 hours of the dynamic test
Obr. 11 Obrázok rezu pneumatiky po 200 hodinách
dynamickej skúšky
[3] BATHE, K.J., WILSON, E.L., PETERSON, F.E.: SAP-IV,
A Structural Analysis Program for Static and Dynamic Response
of Linear Systems, Berkeley, 1973
[4] TEPLÝ, B. Metóda konečných prvkov. VUT, 1990
[5] VAVRO, J., KOPECKÝ, M., SÁGA, M., FANDÁKOVÁ, M.
Nové prostriedky a metódy riešenia sústav tellies II,ISBN 809683337-9-0, Trenčín 2004
Acknowledgement
The work presented in this paper was supported by
VEGA grant No. 1/0530/11.
Literature
[1] AZAR, J.J. Matrix Structural Analysis, Pergamon Press, New
York, 1972
[2] BATHE, K.J. Finite element procedures in engineering analysis.
Englewod Cliffs 1982
Review: prof. Dr. Ing. Milan Sága
prof. Ing. Milan Žmindák, PhD.
_____________________________________________________________________________________________
2 THETA ASE, s.r.o. Český Těšín, CZ
Instytut Metalurgii Ż elaza w Gliwicach, PL
Komisja Śladowej Analizy Nieorganicznej PAN, PL
VILLA LABECO, s.r.o. Spišská Nová Ves, SK
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P.S. 103, 737 01 Český Těšín
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