Table Of ContentTEXTILE SPINNING,
WEAVING AND
DESIGNING
Textile Spinning,
Weaving and Designing
M. G. Mahadevan
ABHISHEK PUBLICATIONS
CHANDIGARH-17
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ISBN: 81·8247·107·9
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CONTENTS
1. Basic Aspects ofT extile Fibers 1
2. Structure and Properties ofT extile Fiber 19
3. Spinning Diagnosis 30
4. Theoretical Basis ofS pinning 53
5. Spinning Methodology 65
6. Textile Weaving 163
7. Braiding Processes 201
8. Designing Mechatronics 231
9. TextileIndustryinIndia 269
One
Basic Aspects of
Textile Fibres
The word fibre creates a mental picture of a long, thin. hair
like objects and indeed textile fibres are like that in general
physical shape.Not all fibres though are suitable for textile
purposes because a textile fibre must possess sufficient
length. fineness, strength and flexibility to be suitable for
manufacture into fabrics. It will be seen later on now they
vary in these respects and how the variations are responsible
for the differing character of materials. It will be seen also
that this definition can apply both to natural and to man-made
fibres.
Filament and staple
'Filament' and 'staple' are two terms represent the two basic
forms of textile fibres. Filament is the name given to a fibre
of continuous length, that is to say it is long enough to be
used in a fabric without increasing its length by adding other
fibres on to it. An example of a natural filament is silk; the
cocoon of a silk-worm can contain about two miles of
continuous twin filaments. Man-made filaments produced by
spinning machines can be many miles long. Staple is the
name given to fibres of limited length. To make a continuous
length of yarn, staple fibres have to be twisted together.
2 Textile Spinning, Weaving and Designing
Staple fibres can range from about one-quarter of an
inch to many inches in length, but in no case do they ever
become long enough to be classed as filament, so the two
terms are quite separate except for the fact that man-made
filaments can be converted into staple fibres by deliberately
cutting them into short lengths. This is a very common way
of processing man-made fibres, but the reverse process is
never carried out. An example of a natural staple fibre is
cotton.
Yarn
A yarn can consist of either staple fibres, or of filaments put
together. Filaments merely need grouping in order to produce
the thickness of yarn required, the length is already there in
the individual filaments. Grouping of filaments is achieved by
twisting them together. The twist, usually quite a small
amount, merely serves to keep to filaments reasonably
together. Staple fibres have to be twisted to make them cohere
into a continuous length of yarn.
The action of twisting forces the fibre surfaces into
contact with each other setting up friction between them
which enables a lengthwise tension of the yarn to be resisted.
In this way a continuous length of yarn can be made even
from very short fibres.
The type of yarn exerts a strong influence on the texture
and appearance of the fabric. In general. filament yarns are
thin, smooth and lustrous and staple fibre yarns are thicker,
fibrous and non-lustrous. An excellent example of these
different characteristics can be seen by comparing the fibrous
nature of the outer wool fabric of a coat or suit jacket with the
smooth lustrous surface of the lining of the garment.
Basic Aspects of Textile Fibres 3
Fabrics
Most fabrics are made from yarns.
Woven fabrics
In their simple form these consist of two series of threads,
warp and weft, interlaced at right angles to each other. The
warp threads run the length of the fabric and the weft threads
run across the width of the fabric. The edge at each long side
of a woven fabric is called the selvedge and it is commonly
of a different construction or appearance, to the rest of the rest
of the fabric because its function is not only to provide a firm
neat edge 'finish to the fabric for the sake of appearance. but
also to provide a secure grip for finishing machinery. For this
latter reason, small regular groups of pin-holes can often be
seen in a fabric selvedge showing where it was held by the
machine pine. Other types of machine use clips which do not
mark the selvedges. The section drawings at the side and the
bottom of the plan show that warp and waft interlace with
each other in a similar manner.
If the threads are closely spaced it can be seen that this
form of interlacing gives a very tight structure because the
alternate interlacings give no room for sideways movement of
the threads. The draping properties of such a structure would
depend entirely on the flexibility of the fibres and yarns. For
example, a square of wire gauze, as used in a laboratory, is
formed by interlacing steel wire in plain weave. As a result a
fairly rigid piece of fabric is produced which is the intention.
This fabric is too rigid to be used for any normal fabric
purpose because steel wire is far less flexible than any textile
fibre or yarn.
A fine cotton calico can be made by interlacing cotton
yarns in plain weave much more closely than the wire gauze,
but because of the softness and flexibility of the cotton, the
resulting fabric is quite supple and is flexible enough for
