Woven Fabric Engineering Part 1 doc

Mechanical Properties EngineeringAnisotropy in Woven Fabric Stress and Elongation at Break 1 Radko Kovar Mechanical Properties of Fabrics from Cotton and Biodegradable Yarns Bamboo, SPF

Woven Fabric Engineering

edited by

Prof Dr Polona Dobnik Dubrovski

SCIYO

Woven Fabric Engineering

Edited by Prof Dr Polona Dobnik Dubrovski

Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher No responsibility is accepted for the accuracy of information contained in the published articles The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods

or ideas contained in the book

Publishing Process Manager Jelena Marusic

Technical Editor Teodora Smiljanic

Cover Designer Martina Sirotic

Image Copyright Roman Sigaev, 2010 Used under license from Shutterstock.com

First published November 2010

Printed in India

A free online edition of this book is available at www.sciyo.com

Additional hard copies can be obtained from publication@sciyo.com

Woven Fabric Engineering, Edited by Prof Dr Polona Dobnik Dubrovski

p cm

ISBN 978-953-307-194-7

WHERE KNOWLEDGE IS FREE

free online editions of Sciyo

Books, Journals and Videos can

be found at www.sciyo.com

Mechanical Properties Engineering

Anisotropy in Woven Fabric Stress and Elongation at Break 1

Radko Kovar

Mechanical Properties of Fabrics from Cotton

and Biodegradable Yarns Bamboo, SPF, PLA in Weft 25

Živa Zupin and Krste Dimitrovski

Wing Tear: Identifi cation of Stages of Static Process 47

Beata Witkowska and Iwona Frydrych

Effects of Topographic Structure on Wettability of Woven Fabrics 71

Alfredo Calvimontes, M.M Badrul Hasan and Victoria Dutschk

Importance of the Cloth Fell Position and Its Specifi cation Methods 93

Elham Vatankhah

Artifi cial Neural Networks and Their Applications

in the Engineering of Fabrics 111

Savvas Vassiliadis, Maria Rangoussi, Ahmet Cay and Christopher Provatidis

Porous Properties Engineering

Prediction of Elastic Properties of Plain Weave Fabric

Using Geometrical Modeling 135

Jeng-Jong Lin

Prediction of Fabric Tensile Strength

by Modelling the Woven Fabric 155

Mithat Zeydan

Data Base System on the Fabric Structural Design

and Mechanical Property of Woven Fabric 169

Seung Jin Kim and Hyun Ah Kim

Contents

Surface Properties Engineering

Surface Unevenness of Fabrics 195

Eva Moučková, Petra Jirásková and Petr Ursíny

Detection of Defects in Fabric by Morphological Image Processing 217

Asit K Datta and Jayanta K Chandra

Investigation of Wear and Surface Roughness of Different Woven Glass Fabrics and Aramid Fibre-Reinforced Composites 233

Haşim Pihtili

Textile Production Engineering

Coated Textile Materials 241

Stana Kovačević, Darko Ujević and Snježana Brnada

Porosity of the Flat Textiles 255

Danilo Jakšić and Nikola Jakšić

Woven Fabrics and Ultraviolet Protection 273

Polona Dobnik Dubrovski

Textile Composite Engineering

Microwaves Solution for Improving Woven Fabric 297

Drago Katovic

Composites Based on Natural Fibre Fabrics 317

Giuseppe Cristaldi, Alberta Latteri, Giuseppe Recca and Gianluca Cicala

Crashworthiness Investigation and Optimization

of Empty and Foam Filled Composite Crash Box 343

Dr Hamidreza Zarei and Prof Dr.-Ing Matthias Kröger

Effects of the Long-Time Immersion on the Mechanical Behaviour

in Case of Some E-glass / Resin Composite Materials 363

Assoc.prof.dr.eng Camelia CERBU

Simulations of Woven Composite Reinforcement Forming 387

Philippe Boisse

VI

Woven Fabrics are fl exible, porous materials used for clothing, interior and technical applications Regarding their construction they posses different properties which are achieved to satisfy project demands for specifi c end-use If woven fabrics are to be engineered

to fi t desired properties with minimum production costs, then the relationship between their constructional parameters and their properties must be fi rst quantitatively established So a great attention should be focused on woven fabric engineering, which is an important phase

by a new fabric development predominantly based on the research work and also experiences For the fabric producer’s competitiveness fabric engineering is the important key for success

or at least better market position

Nowadays, a great attention is focused on the fastest growing sector of textile industry, e.g technical textiles, which are manufactured primary for their technical performance and functional properties rather than their aesthetic or decorative characteristics Technical woven fabrics are used in a large number of diverse applications such as protective clothing,

in agriculture, horticulture, fi nishing, building and construction, fi ltration, belting, hygiene, automobiles, packaging, etc Woven technical fabrics are also the reinforcement component

in engineering material no.1, e.g composites, which offer signifi cant opportunities for new applications of textile materials in the area of aerospace, defence, construction and power generation, land transportation, marine

The main goal in preparing this book was to publish contemporary concepts, new discoveries and innovative ideas in the fi eld of woven fabric engineering, predominantly for the technical applications, as well as in the fi eld of production engineering and to stress some problems connected with the use of woven fabrics in composites

The book is organized in fi ve main topics and 20 chapters First topic deals with the Mechanical Properties Engineering For technical applications the mechanical properties of woven fabrics are one of the most important properties Many attempts have been made

to develop predictive models for mechanical properties of woven fabrics using different modelling tools and to defi ne the infl uence of woven fabric structure on some mechanical properties This topic includes six chapters dealing with: prediction of woven fabric tensile strength using design experiment, artifi cial neural network and multiple regression (chapter 1), prediction of plain fabric elastic properties using fi nite element method (chapter 2), woven fabrics tensile properties modelling and measuring (chapter 3), the infl uence of biodegradable yarns (bamboo, polylactic acid, soybean protein) on mechanical properties of woven fabrics (chapter 4), experimentally verifi ed theory of identifi cation of stages of cotton fabric by static tearing process (chapter 5), and the data base system of the fabric structure design and mechanical properties (chapter 6)

The second topic is focused on Porous Properties Engineering Woven fabrics are porous materials which allow the transmission of energy (electromagnetic radiations: UV, IR,

Preface

light,etc.) and substances (liquid, gas, particle) and are, therefore, interesting materials for different applications The chapters involved within this topics cover: the theory of fl at textiles porosity and the description of a new method for porosity parameters assessment based on the air fl ow through the fl at fabrics (chapter 7), the modelling of air permeability behaviour

of woven fabrics using artifi cial neural network method (chapter 8), and the theory of the UV protective properties of woven fabrics with the emphasis on the infl uence of woven fabric geometry on ultraviolet protection factor (chapter 9)

The woven fabric surface unevenness prediction and evaluation (chapter 10), detection of woven fabric faults by morphological image processing (chapter 11), and the research dealing with the surface properties of PES fabrics on the basis of chromatic aberration and dynamic wetting measurements (chapter 12) are discussed within the third topic Surface Properties Engineering

The forth topic of the book deals with the Textile Production Engineering, where the use of microwaves by fi nishing processes (chapter 13), basic properties and advantages of coated fabrics with woven component as substrate (chapter 14), and the importance of the cloth-fell position (chapter 15) are discussed

The last topic Textile Composites Engineering involves the contributions dealing with mostly woven fabrics as reinforcement phase in polymer composites It comprehends the characteristics of natural fabrics in composite ranging from mat to woven fabrics (chapter 16), crashworthiness investigation of polyamid composite crash boxes with glass woven fabric reinforcement (chapter 17), the infl uence of the immersion time in different environments (water, natural seawater, detergent/water liquid) on some mechanical properties of E-glass woven fabric reinforced polymer composites (chapter 18), the investigation of weight loss of composites with glass woven fabric reinforcement as well as with aramid fi bres reinforcement (chapter 19), and simulations of composite reinforcement forming (chapter 20)

The advantage of book Woven Fabric Engineering is its open access fully searchable by anyone anywhere, and in this way it provides the forum for dissemination and exchange of the latest scientifi c information on theoretical as well as applied areas of knowledge in the

fi eld of woven fabric engineering It is strongly recommended for all those who are connected with woven fabrics, for industrial engineers, researches and graduate students

a Mechanical Properties Engineering

Although weave anisotropy is well known, tensile properties are usually theoretically and experimentally investigated namely for principal directions; the main reason is probably complexity of deformation and stress distribution when the load is put at non-principal direction In this section we shall try to make a step to describe and perhaps to overcome some of these problems

In practical use, the fabrics are often imposed load in arbitrary direction, bi-axial load or complex load composed of elongation, bend, shear and lateral compression To predict tensile properties becomes more and more important with development of technical textiles Now only main difficulties, connected with the topic of this section, will be outlined:

a At diagonal load great lateral contraction occurs It causes complex distribution of stresses It results in stress concentration at jaws when experiment in accordance with

EN ISO 13934-1 is used

b There are yarns cut ends in the sample where tensile stress starts from zero

c Shear deformation causes jamming of yarns, what can change yarn properties Strength

of the yarn in the fabric can be higher than the strength of free yarn

There are not available many publications, based on real fabric structure and solving the problem of woven fabric tensile properties in different directions The reason is mentioned long range of problems and difficulties Monographs (Hearle et al., 1969 and Postle et al., 1988) are involved in problems of bias fabric load only marginally (Hu, 2004) is oriented on influence of direction on properties such as tensile work, tensile extension, tensile linearity etc and uses another approach Fabric shear at bias extension is investigated in (Du & Yu, 2008) Model of all stress-strain curve of fabric, imposed bias load, is introduced for example

in (King, M J et al., 2005) with the respect to boundary conditions (stress concentration at

Woven Fabric Engineering

2

jaws) In (Peng & Cao, 2004) is area of fabric sample separated into 3 zones with different characteristics of bias deformation Experimental models of woven fabric deformation in different directions are presented by (Zouari et al., 2008) Often the mechanics of continuum approach, coming out of prediction of Hook’s law validity, is used, for example, in (Du &

Yu, 2008; Hu, 2004; Peng & Cao, 2004 and Zheng et al., 2008) A new method of anisotropy measuring is proposed by (Zheng, 2008) etc

This section is oriented first of all on anisotropy of rupture properties of weaves, imposed uniaxial load in different directions The main goal is to develop algorithm for calculation of plain weave fabric breaking strain and stress under conditions of simulated idealized experiment There are two ways of ideal uni-axial woven fabric loading (details are in section 2): (a) Keeping stable lateral (i.e perpendicular to direction of load) dimension, (b) Keeping lateral tension on zero (i.e allowing free lateral contraction)

In this chapter rupture properties will be analyzed for plane weave structure

2 Nomenclature

β0, β – angle of warp yarns orientation to the load direction before and after load [rad]

γ – shear angle [rad]

ε – relative elongation or strain [1]

μ – yarn packing density, a share of volume of fibrous material and volume of yarn [1]

h0, h – length of the fabric, taken for calculation, before and after fabric elongation [m]

l0, l – length of the yarn in a crimp wave [m]

L0, L – projection of the length of the yarn in fabric plane before and after load [m]

s0, s – component of yarn length L into direction perpendicular to load [m]

p – spacing of yarns (pitch) [m]

S – fabric sett (yarn density) [m-1]

t – fabric thickness [m-1]

T – yarn linear density [Mtex]

Main subscripts: y – yarn, f – fabric, 1 – warp yarn or direction of warp yarns, 2 – weft yarn

or direction of weft yarns, 1,2 – warp or weft yarns, 0 – status before load (relaxed fabric), b – status at break, d – diagonal direction (45 º), n – not-broken yarn, h – horizontal or weft direction, v – vertical or warp direction

3 Models of woven fabrics rupture properties

Modelling always means simplification of reality and, in our case, idealizing the form of the load When we wish to simulate experimental investigation of similar property, we should start with brief description of standard fabric rupture properties measuring with the use of

EN ISO 13934-1 (strip test) standard Fast jaws keep the sample in original width (width before load) what results in tension concentration at these jaws Break usually occurs near the sample grip sooner then real fabric strength is reached In Fig 1 a, b are these critical points of the sample marked by circles

Anisotropy in Woven Fabric Stress and Elongation at Break 3

Fig 1 Tension concentration at jaws and methods of its elimination

There are two main ways how to avoid the problem of tension concentration that occurs when using standard method; sample dimensions are in Fig 1 c First is reduction of fabric tension at jaws by narrowing the sample in central part, Fig 1 d (Zborilova & Kovar, 2004) and 1 e (CSN standard 80 0810) This solution improves the results but some places with tension concentration stay Till now the best results provides a new method (Kovar & Dolatabadi, 2010), Fig 1 g; details of the method will be described in section 4.1

When we wish to model fabric rupture properties and to avoid the problems with uneven tension distribution, we need to analyze a part of the fabric imposed constant load Virtually there are two idealized situations:

a To prevent sample from lateral contraction, i.e to keep the fabric at original width b0 This can simulate an experiment with infinite fabric width, when the influence of the sample margins becomes negligible Restriction of lateral contraction must be, in practical experiments, connected with biaxial load, because some complementary load arises in the direction perpendicular to the direction of main load

b To allow free lateral contraction of the fabric This model can simulate an experiment with flexible jaws that change the width simultaneously with fabric lateral contraction,

or partly infinite fabric length, where the effect of fast jaws will not change sample relative elongation at break This model is more complicated owing to fabric jamming and cut ends of yarns under load Tensile stress in yarn at the cut end is zero and increases gradually due to yarn-to-yarn friction

Yarn parameters and properties

From parameters and properties of yarn are, for fabric tensile properties investigation, most important: (a) Yarn cross-section as variable parameter For simplification we can use yarn

diameter d For rough estimation of d can be used well known formula (1), where ρ is density of fibrous material and μ is average yarn packing density, the most problematic parameter Its average value in free yarn used to be around μ0 ≈ 0.5 This could be used for fabric with low packing density (lose fabric) At tight fabric yarn cross-section becomes flat

and packing density increases Here can be used effective yarn diameter def It is variable parameter, described as distance of yarns neutral axes in cross-over elements In tight fabric

can packing density reach, near warp and weft yarn contact, approximately μef ≈ 0.8 In fabric near the break, mainly at diagonal load, yarn packing density reaches maximum

possible value μb ≈ 0.9 (b) Yarn stress-strain curve, which can be for some purposes

replaced by yarn breaking stress Fyb (strength) and strain εyb Due to yarn jamming breaking