CONTENTS
Chapter Title Page
1. INTRODUCTION OF TEXTILE FIBRES
1. 1. Development ………………………………….. 1
1.2. Fibre and its characteristics ……………… 2
1.3. Classification of fibres ……………………… 4
1.4. Polymerisation ………. …………………. …… 8
1.5. Properties of textile fibres ………………. 15
1.6. Importance of textiles ……………………. 21
2. NATURAL FIBRES
2. 1. Introduction …………………………………. 27
2.2. Cotton …………………………………………. 30
2.3. Miscellaneous Seed and Fruit Fibres .. 50
2.4. Jute ………………………… ……………… …. 51
2.5. Flax ……………………. ……………………… 57
2.6. Hemp ………………… 0 .. …………………….. 62
2.7. Ramie or China grass …………………….. 65
2.8. Miscellaneous bast fibres ……………….. 67
2.9. Leaf fibres ……………………………………. 68
2.10. Asbestos …………….. ………………………. 70
2. 11. Wool ……………………………………………. 71
2.12. Other hair fibres ………………. ………….. 98
2.13. Silk ……………………………….. …………. 100
3. REGENERATED FIBRES
3.1. Introduction ……………. …….. …………. 119
3.2. Viscose rayon ………… ……… ….. ………. 120
3.3. Cuprammonium rayon …….. o •••••••••• • •• 127
3.4. Polynosic rayon ……….. …………………. 129
3.5. Nitro cellulose …………………….. …. ….. 130
3.60 Cellulose acetate ……. …………. … … ….. 131
3.7. Staple rayon ……… …………….. ………… 136
3.8. Lyocell ………………………………………. 137
3.9. Minor regenerated fibres ………………. 138
4. SYNTHETIC FIBRES
4.1. Introcluction ……………………………….. 145
4.2. Nylon ………………………………………… 146
4.3. Aramid ………………………………………. 158
4.4. Polyester ……………………………………. 161
4.5. Acrylic ……………………………………….. 168
4.6. Polypropylene …………………………….. 176
4.7. Miscellaneous fibres ……………………. 178
5. SPECIALITY FIBRES
5.1. Glass and carbon ………………………… 186
5.2. Spandex …………………………………….. 187
5.3. Metallic fibres …………………………….. 188
5.4. Reflective materials ……………………… 191
5.5. Silicate fibres ……………………………… 195
6. IDENTIFICATION OF TEXTILE FIBRES
6.1. Introduction ……………………………….. 197
6.2. Burning test ……………………………….. 198
6.3. Staining tests ……………………………… 199
6.4. Chemical solubility test ……………….. 204
6.5. Microscopical tests ……………………… 204
6.6. Elemental analysis for fibres …………. 209
6.7. Melting point of fibres ………………….. 210
6.8. Infrared spectroscopy of fibres ………. 212
References ………………………………………………. 217
Appendices ………………………………………………. 218
(A) Important dimensional, physical, mechanical
and chemical properties of fibres ………………………………………… 219
(B) Physical and mechanical properties of
textile fibres ……………………………….. 220
(C) Composition of vegetable fibres ……… 222
(D) HOW TO BUY COTTON? ………………. 223
Glossary ………………………………………………….. 232
CHAPTER 1
INTRODUCTION OF TEXTILE FIBRES
1.1. Development
Fibres abound in nature. Since ages human beings have been increasingly dependent on fibres and fibrous materials for shelter and housing, coverage, packaging, protection and warmth. In ancient times, for protection and warmth, man depended on animal hides, skins and furs. As he looked around for more practical, elegant and comfortable fibres, man found fibres produced by plants, insects and animals. Using his brain, he developed methods by which each of these fibres could be twisted or spun together to form a thread or yarn. The threads and yarns were then put through mechanical processing such as weaving or interlacing for obtaining flexible,’ warm and highly comfortable, stable, durable and useful material known as cloth or fabric.
Till about the turn oftlle nineteenth century, only natural fibres existed. Even today cotton, wool, jute, flax and silk are the most important natural fibres used for making elegant textiles.
In recent years, this list has been supplemented by invention of variety of new fibres called ‘man-made’ fibres (which include ‘regenerated’ and ‘synthetic’ types). These materials have complemented the properties of the important natural fibres and have made possible many of the major advances in product performance. The world wide production and consumption of textile fibres have increased considerably. The increase in total fibre production is mainly due to growth in population whereas the trend from naturally occurring fibres to man-made fibres reflects many factors inc1uding their desirable physical properties, uniformity, stability of supply and in many cases comparatively low price tag. The man-made fibres become particularly effective and desirable when they are blended with other fibres (mainly cotton or wool).
This chapter is concerned with general description of fibres that in most cases from the raw-materials from which yarns and fabrics are produced.
1.2. Fibre and its characteristics
A fibre is a fine single filament which is used in making of yarns and thread which comprise of the basic component of all textile items- such as fabrics, mats, strings, cords, twines and ropes. It is defined as a fine strand of tissue of plant, animal or any synthetic material drawn out into filament and subsequently cut into required length.
1.2.1. Characteristics of a fibre
(i) Length to diameter ratio
For a fibre to be suitable for textile purposes, its length to diameter ratio must be at least in the range of hundreds. This physical structure enables fibres to be twisted together to form yarns and threads. Larger items having bigger diameters such as cords and ropes are made by first assembling fibres into yarns and in turn assembling them into cords and further into ropes through twists and turns.
(ii) Strength
A fibre for textiles must be strong, Its inherent high strength enables it to withstand the rigours of the spinning (yarn or thread-making) and weaving processes and to provide the desired strength in the woven cloth.
(iii) Flexibility
A fibre should be essentially flexible. Flexibility permits the fibres to be duly spun and woven and gives to the textile fabric its unique folding and draping characteristics.
(iv) Fibre-length
Fibre-length is an important physical parameter. Fibres can be infinitely long, but they must not be shorter than 6-12 mm (1/4-1/2 in) in length, so as to ensure that they are held together by the imparted twists during spinning.
(v) Elasticity and resilience
Besides having good strength and flexibility, a textile fibre should also have a good degree of elasticity and resilience without detrimental brittleness. For fibres for clothing, garment, a good degree of moisture absorption is desirable for good feel and comfort.
(vi) Density
The density of the fibre largely influences its draping qualities when it is made into a fabric. Smaller density and lower diameter make a finer fibre. Fabrics made from very light fibres may not drape well; if the fibre is too dense.