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Table of Contents
                            preface_Advances in Modern Woven Fabrics Technology
part 1
01_Electro-Conductive Sensors and Heating
Elements Based on Conductive Polymer
Composites in Woven Fabric Structures
02_Smart Woven Fabrics in Renewable Energy Generation
part 2
03_Mechanical Analysis of Woven Fabrics:
The State of the Art
04_Finite Element Modeling
of Woven Fabric Composites at Meso-Level
Under Combined Loading Modes
05_Multiaxis Three Dimensional (3D) Woven Fabric
part 3
06_Functional Design of the Woven Filters
07_Color and Weave Relationship in Woven Fabrics
part 4
08_Sensory and Physiological Issue
09_Superhydrophobic Superoleophobic Woven Fabrics
10_The Flame Retardant Nomex/cotton
and Nylon/Cotton Blend Fabrics for Protective Clothing
11_Liquid Transport in Nylon 6.6. Woven Fabrics
Used for Outdoor Performance Clothing
                        
Document Text Contents
Page 1

logo1.eps


ADVANCES IN MODERN
WOVEN FABRICS

TECHNOLOGY


Edited by Savvas Vassiliadis

Page 2

Advances in Modern Woven Fabrics Technology
Edited by Savvas Vassiliadis


Published by InTech
Janeza Trdine 9, 51000 Rijeka, Croatia

Copyright © 2011 InTech
All chapters are Open Access articles distributed under the Creative Commons
Non Commercial Share Alike Attribution 3.0 license, which permits to copy,
distribute, transmit, and adapt the work in any medium, so long as the original
work is properly cited. After this work has been published by InTech, authors
have the right to republish it, in whole or part, in any publication of which they
are the author, and to make other personal use of the work. Any republication,
referencing or personal use of the work must explicitly identify the original source.

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 Niksa Mandic
Technical Editor Teodora Smiljanic
Cover Designer Jan Hyrat
Image Copyright meirion matthias, 2010. Used under license from Shutterstock.com

First published July, 2011
Printed in Croatia

A free online edition of this book is available at www.intechopen.com
Additional hard copies can be obtained from [email protected]



Advances in Modern Woven Fabrics Technology, Edited by Savvas Vassiliadis
p. cm.
ISBN 978-953-307-337-8

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Advances in Modern Woven Fabrics Technology



114

I importance factor for each sample is calculated function the relationship:


N

I
D

 (2)

where: N is the sum of points awarded;
D - total number of decisions.
The filter media 12 functions obtained by weaving defined in Table 2 were divided into two
groups: 6 primary and 6 secondary functions. Apply for group relationship of the main
functions, which will be used to design, to establish the number of decisions as follows:


 6 6 12 15

6 2
D C

 
   (3)



Func-
tion

Decisions N I
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

F1 0.5 0.5 1 1 0.5 3.5 0.233
F2 0.5 0.5 1 1 0.5 3.5 0.233
F3 0.5 0.5 0.5 0.5 0.5 2.5 0.166
F4 0 0 0.5 0.5 0 1 0.066
F5 0 0 0.5 0.5 0 1 0.066
F6 0.5 0.5 0.5 1 1 3.5 0.233

Table 3. Coefficient calculation Ranking



The name of the function
Specific technical

dimension

Structural characteristics
of fabric

to separate the phases of a
heterogeneous mixture

pore size
fineness and density of
yarns

to ensure filtration fineness
pore shape and
distribution, filter
medium fineness

fineness and density of
yarns, weave

to ensure filtering velocity
adequate filtering active
area

fineness and density of
yarns

to be dimensionally stable
during operation

structural and mechanical
characteristics of yarn
and fabric

the mechanical
characteristics of the of
yarns

to withstand the action of
mechanical factors during
operation

tensile strength
burst resistance

the mechanical
characteristics of the of
yarns

to withstand the erosive effects
of the environment

chemical resistance
the nature of raw
material

Table 4. Priority functions of the filter media and their assessment criteria

In Table 3 are comparative analysis, two by two principal functions. The last column of the
table are shown the importance scores and values of each corresponding functions. Based on

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Functional Design of the Woven Filter



115

the values of the coefficients of importance to obtain the hierarchy of the main functions in
the following sequence: F1, F2, F6, F3, F4, F5.
Priority functions set out in this way are taken into consideration when designing or
redesigning filter media weaved in accordance with functionality criteria. In this respect the
assessing criteria of woven filter media priority functions are summarized in Table 4.
The parameters specific to the woven filter with simple structure that will provide
functional design criteria are: the relative porosity, pore shape and size, the pore
distribution, the active filtering surface.
The structural characteristics of woven fabric,which determine the parameters of filter fabric
are: yarns count, thread density and weave.

3. Structural and functional characteristics of the fabric filters with simple
structure

Characterization and use of the fabric estimating filters with simple structure can be made
by means of specific structural and functional characteristics (Behera, 2010; Cioară, 2002).
Among these characteristics are mentioned: porosity, pore size and architecture, active
filtering surface environment and filter fineness.

3.1 Porosity
Porosity, feature size filter material is the property of having pores in their structure
(Medar&Ionescu, 1986; Cay et al., 2005). In connection with the porosity are two distinct
notions:
- relative porosity, apparent or open, when taking into account only pores that

communicate with each other;
- absolute porosity, effective or real, if we take into account all the pores, i.e. those who

are isolated.
Fluid flow through uniform or uneven spaces created by the filter medium, while
maintaining the quality of filtration, filtration efficiency and smoothness and filtering
capacity are issues directly related to the porosity of filter media.
Fluid movement across the filter medium is described by the filtration rate, defined as
the maximum volume of fluid passing per unit time through unit area of filter. Porosity
refers to the filter media pore volume per unit volume and is typically seen in relative
units. Generally, the textile filtering media are inhomogeneous because the filter
permeability changes during the exploitation. The medium in homogeneity can be
bigger or smaller, depending on the structure of woven filter.

3.2 Pore dimensions and architecture
An important feature of each filter surfaces is the existence of pores which penetrate the
entire thickness of the filter and retain solid particles larger than the pores in the cross
section of their most narrow, but allow passage of fluid that carried them. Small pore is a
void within a solid body. After dimensions are distinguished (Medar&Ionescu, 1986) : fine
pores with a diameter greater than 20 μm (invisible to the naked eye) and coarse pore
diameter greater than 20 μm (visible to the naked eye). The way of communication with the
outside pores can be:
- open, when communication with the outside;
- closed, when no communication with the outside.

Page 251

Liquid Transport in Nylon 6.6. Woven Fabrics Used
for Outdoor Performance Clothing



239

8. Conclusion
Miller and Tyomkin21 state that when a porous material such as a fabric is placed in contact
with a liquid, spontaneous uptake of liquid may occur. Law9 observed that if the wicking
distance is plotted against time, the graph is expected to have an initial rapid rate of change
which decreases subsequently because water is first sucked into wider capillary channels by
the action of surface tension. As the wicking process proceeds further, the total viscous
resistance to the flow increases and the rate of flow decreases. In the case of the vertical strip
test, the height and the mass of the water absorbed in the sample strip will gradually reach a
quasi-equilibrium state when they are balanced by the hydrostatic head of water. In the case
of the horizontal strip test, if the supply water is unlimited, the rate of penetration will
gradually become constant.9 In thick fabrics vertical wicking would continue with little
effect of evaporation until a quasi-equilibrium state is reached when the wicking level in the
fabric is balanced by gravity.10
In this work vertical and horizontal wicking of samples S1F and S2F did not continue
indefinitely indicating that due to the combination of low fabric weight and thickness the
maximum wicking height was not only influenced by gravity but also by evaporation. The
rate of evaporation of liquid therefore determined the equilibrium point for both vertical
and horizontal wicking of samples S1F and S2F indicating good properties required for
eliminating perspiration discomfort which would cause fabric wetness with resulting
problems of freezing in winter or clamminess22 in summer. In most cases, the leading front
of the water rise observed at the end of each test period felt dry to the touch which can be
attributed to the rapid liquid evaporation of the fabrics.
In textured yarns, the manner in which the liquid is transported through the fabric is
determined by the minute loops or coils that characterize air –textured yarns which act as
pores that vary in shape and distribution and may or may not be interconnected. Hsieh6
noted that pore variation and distribution leads to preferential liquid movement towards
smaller pores, resulting in partial draining of previously filled pores in the fibrous structure.
In all cases studied in this work, tests showed that there is a good linear relationship
between the logarithm of the wicked liquid ( l ) and the logarithm of the wicking time ( t )
indicating that the wetting liquid follows diffusive capillary dynamics20 even though for
sample S1F in most cases the exponential values were high compared to sample S2F due to
evaporation from the parallel packed filaments of the yarn structures.
The high k values of fabrics containing textured weft yarns indicate the characteristics of a
non-homogenous capillary system where wicking is a discontinuous process due to the
irregular capillary spaces of varying dimensions.11 Rapid wicking is retarded by the
‘absorber’ textured weft yarns which are more bulky and act as temporary liquid reservoirs
as all the voids are filled up. On the other hand, the inter-filament wicking rate is increased
once the liquid is transferred to the flat ‘runner’continuous filament warp yarn due to
capillary sorption11 resulting in spiked wicking behaviour observed.
Wicking is also affected by fabric construction. Fabric sample S2F wicked more rapid in the
warp than in the weft direction due to the high density of ends in the fabric. If the filament
packing in the yarn is assumed to be an idealized or closely packed assembly23 there will be
more capillaries in the warp than in the weft direction due to the distribution in the number
of ends and picks.
Outdoor active wear such as jackets are infrequently washed and research24 results have
shown that a standard 5 washes of vests used for mountaineering resulted in a significant

Page 252

Advances in Modern Woven Fabrics Technology



240

increase in their wicking performance. Even though a spin finish was applied to fabrics S1F
and S2F during finishing to give surface properties which can allow liquid flow, the
durability of the spin finish to washing was insignificant since laundering of fabrics resulted
in a significant increase in their wicking performance. Washing therefore did not lead to the
collapse of the capillary system of the fabric but results in the re-arrangement of the
capillaries between filaments due to the washing liquid movements and the relaxation of the
textile structure during drying.24

9. References
[1] Barnes J.C and Holcombe B.V., Textile Res. J., 66(12), 777-786, 1996
[2] Brownless N.J., Anand S.C., Holmes D.A. and Rowe T., J. Text. Inst., 87 Part 1, No.1, 172-

182, 1996.
[3] Brownless N.J., Anand S.C., Holmes D.A. and Rowe T., Textile Asia, August 1996, 77-80.
[4] Slater K.,Comfort Properties of Textiles, Textile Progress, Volume 9, Number 4, 1-91,

Textile Institute 1977.
[5] Yoon H.N. and Buckley A., Text. Res. J., 54, 289-298, 1984.
[6] You-Lo Hsieh, Text. Res. J., 65(5), 299-307, 1995
[7] Brownless N.J., S.c. Anand, D.A. Holmes and T. Rowe, World Sports Activewear,

Volume 2, No.2, 36-38, 1996
[8] A.B. Nyoni and D. Brook, J. Text. Inst., Vol.97, No.2, 2006, 119-128.
[9] Law Y.M.M., Ph.D Thesis, University of Leeds, 1988.
[10] Zhuang Q., Ph.D. Thesis, University of Leeds, 2001.
[11] Kissa E., Text. Res. J., 66 (10), 660-668, 1998
[12] Miller B., International Nonwovens Journal, Volume 9, No.1, Spring 2000.
[13] Pronoy K. Chatterjee and Hien V. Nguyen., Mechanism of Liquid Flow and Structure

Property Relationships., Absorbency, Chapter II., Edited by Pronoy K. Chatterjee,
Elsevier Scientific Publishers; Amsterdam; New York, NY: 1985.

[14] Harnett P.R. and Mehta P.N., Tex. Res. J., 54, 471-478, 1984
[15] A.B Nyoni., (2003), PhD Thesis, University of Leeds.
[16] Hepburn C.D., PhD. Thesis, University of Leeds 1998
[17] Leijala A and Hautojarvi. J, Text. Res. J.,68(3), 193-202, 1998.
[18] Blyth G.T., Ph.D. Thesis, University of Leeds, 1984.
[19] Laughlin R.D. and Davies J.E., Text. Res. J., 31,904-910, 1961.
[20] Anne Perwuelz, Mthilde Casetta and Claude Caze, Polymer Testing, Volume 20, Issue

5, 553-561, 2001.
[21] Miller B. and Tyomkin. I., Text. Res. J., Volume 54, 706-712, Nov. 1984
[22] Rees W.H., Text. Month, 59-61, August 1969
[23] Hearle J.W.S., Grosberg P., and Backer S., Structural Mechanics of Fibres, Yarns, and

Fabrics. Volume 1, 1969, John Wiley; New York, NY, USA.
[24] A.B Nyoni and D.Brook, Textile Research Journal ,Vol.80(8), 2010, 720-725.

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