II. Reading.

Exercise 2. Read the text.

The Characteristics of Textile Fibers Part I

All the materials used in the manufacture of clothing are called textiles and are made of either long or short fibers. The whole process of textile manufacture consists of the combination of fiber with fiber.

From the masses of fibrous substances the textile workers of all lands have selected those materials which seem to them most suitable. To be suitable for textile purposes a fiber must possess certain properties and qualities such as length, strength, cohesiveness, elasticity and many others. Principal fibers now in use – wool, silk, cotton, flax are natural fibers. These fibers have come to us from prehistoric times. Throughout past centuries a few simple fibers, particularly cotton, linen, wool and silk have been used mainly for clothing purposes. But today these fibers with the exception of silk, are being widely used for industrial purposes. Actually there is hardly any other fiber which can compete in usefulness with cotton, flax, wool and silk. It is surprisig that only these four fibers are suitable for modern textile purposes.

For a textile fiber to be really important and useful it must be available in a large quantity and cheap. Further a fiber must be reasonable durable under everyday conditions and be capable of being dyed in a wide variety of fast shades.

Considering the individual fibers the following properties are of importance:

1. shape, length, thickness, shape of cross section,

2. strength

3. extensibility and elasticity

4. softness

5. plasticity

6. solubility in aqueous and organic solvents

7. general durability

8. lustre. Useful properties of another kind are below:

9. behaviour towards dyes

10. resistance to influences, including a) light, sunlight; b) heat; c) bacteria, mildew, various insects;

d) wet or damp conditions; e) abrasion and wear; f) corrosive chemicals; g) creasing.

Cotton and Flax Part II

We will look at some properties of cotton and flax. Cotton is the most important vegetable fiber used in the textile industry. The ease with which cotton fiber can be transformed into yarn and its cheapness of production have caused it to take the leading place among textiles.

The strength of cotton fibers is relatively high compared with their fineness. It’s strength increases when wet. However cotton fibers are not very elastic, that is why cotton fabrics crease easily. They can also be easily dyed absorbing moisture well. As cotton fibers are good conductors of heat they have a cooling effect when worn in hot weather.

Cotton is used for clothes of all kinds, for shoe uppers, for household textiles, for canvas and sail clothes, which must be very strong through rather thin.

Cotton is also used for radio insulations and wire insulation in the industrial electrical would and in many other branches of industry.

Cotton linters are used in the manufacture of chemical fibers as well.

Flax fibers are vegetable fibers. The flax fiber is recovered (obtained) from the inner stem of the plant. To get the flax fibers are much more difficult and involves greater expense. The commonest form of obtaining these fibers is known as “retting”. The harvested plants are steeped in water for some time. Then through the action of fermentation the fibers can be easily separated from the woody stem and outer bark. The vegetable gum is dissolved by the action of moisture and heat.

All unwanted parts of the plant are mechanically removed, leaving only the flax fibers. These fibers are made up of numerous filaments, which are separated and constitute the raw fibers for manufacture. The length of these fibers ranges from an inch (2,54 cm) upwared and are comapatively fine and strong. The colour of the fibers at this stage is not white.

Linen is used where strength, lustre and absorbing power and stiffness are desired. Flax is considered to be the best natural fiber possessing tensile strength and durability. It is used in towelling, decorative coverings (table cloths), household.

Linen is more expensive than cotton because of a great deal of care is required in producing the fiber from the stalk and in bleaching the fabric.