11. Textile fibres

New words and word-combinations to be remembered:

fibre волокно

thread нитка

to investigate досліджувати according to відповідно до chemical composition хімічний склад artificially штучно man-made fibres штучні волокна property властивість

resistance to outdoor exposure стійкість до атмосферної дії

rayon fibres штучний шовк

organic compound органічна сполука

raw material сировина

in order to для того щоб

solid state твердий стан

liquid state рідкий стан

strength міцність

application застосування

spuming solution прядильний розчин

breaking strength міцність проти розриву

resistance to abrasion стійкість до тертя

thermal ageing термічне старіння

consumer goods товари широкого вжитку

haberdashery галантерейні вироби

tyre шина

knitted fabrics трикотажні тканини

The fibres and threads which are supplied at present to the textile industry are very diverse. A special classification is established for the convenience of investigating them. This classification is based on the division of fibres and threads according to the method of production and their chemical composition.

According to their origin textile fibres and filaments can be subdivided into natural and man-made. Fibres which are made by man artificially with the aid of chemical and physical processes are named man-made fibres.

All fibres used nowadays may be divided into two classes: natural and chemical or man-made fibres. The former includes the traditional fibres: cotton, linen, wool and silk, the latter includes all the artificial fibres made by man, the so-called chemical or man-made fibres.

Man-made fibres are not only substitutes for natural fibres. Many properties of man-made fibres excel those of natural fibres: breaking, landing strength, friction resistance, resistance to chemical action, to outdoor exposure, and ultraviolet rays, to water and microorganisms and very high temperatures.

Man-made fibres are divided into rayon fibres and synthetic fibres, (li|>ending on the raw material.

Natural high-molecular organic compounds serve as raw material bl rayon fibres. This is chiefly plant cellulose: wood, cotton, acetylcel-lulose.

Rayon fibres consist of the same natural molecules as the raw material. The chemical processes, which take place during rayon fibre pioduction, change the arrangement of the molecules, the chemical eities and physical form of the substance.

In order to obtain continuous filaments (threads) it is necessary to leparate the molecules which are located in the cellulose, impart mobility to them, i.e., to transform them from solid to liquid state, to make the molecules move, disposing parallel to each other in one direction. Only by this arrangement of the molecules the rayon fibres will assume sufficient strength.

There are three methods for obtaining cellulose solutions: viscose, acetate and cuprammonium.

The basis of all chemical fibre production is to take substance which can be brought into a viscous or plastic state and to form from it the Ю oiled spinning solution. This solution is forced by mechanical me miis through small holes or spinnerets and then solidifies and turns Into very fine, continuous filaments.

Synthetic fibres include such fibres whose molecules are synthe-lized, built anew chemically from simple substances. Low-molecular compounds serve as the raw material for deriving synthetic fibres such U phenol, benzol, ethylene, chlorine, acetylene, carbon and other мЬ.lances which are mostly products of processing coal, petroleum and natural gases.

Synthetic fibre producing factories receive monomers and convert thorn into polymers.

According to their chemical structure the synthetic fibres are divided into two groups: heterochain fibres and carbochain fibres.

Heterochain fibres are derived from polymers whose macromole-cules contain in the main chain not only carbon atoms, but also atoms of oxygen, nitrogen, sulphur and other elements.

The group of heterochain fibres is in its turn divided into two subgroups: polyamide fibres and polyester fibres.

Carbochain fibres are fibres derived from polymers whose macro-molecules contain only carbon atoms in the main chain.

The carbochain group includes fibres of polyacrylonitril and copoly­mers.

Wide application of synthetic fibres is due to their high properties, such as: high indices of breaking strength, elastic recovery, great resilience, light weight, resistance to abrasion, acids, oxidants, alkali, biological effects, outdoor exposure, thermal ageing, high temperatures. They possess a sufficient length, fineness, extensibility, elasticity, pliability and cohesiveness. They are not susceptible to ultraviolet rays, to mould and microorganisms.

Synthetic fibres are used for making consumer goods: cloth, knitted fabrics, nonwoven textile material, haberdashery (ribbon, lace, tulle, braiding), carpets, fur, underwear; as well as in many branches of national economy as for making tyres, conveyor belts, ropes, fishing tackles, filter fabrics, insulation and industrial material.

Answer the following questions:

1. What classes may all fibres be divided into?

2. What is the classification of fibres based on?

3. What properties do man-made fibre possess?

4. Where are man-made fibres used?

5. What groups are man-made fibres divided into?

6. What serves as raw material for rayon fibres?

7. What serves as raw material for deriving synthetic fibres?

8. What properties do synthetic fibre possess?

9. Where are synthetic fibres used?

Speak on textile fibres and filaments using the following word-com­binations:

— classification: according to origin, to the method of production, chemical composition;

— properties of man-made fibres;

— raw material for rayon fibres;

— the chemical processes which take place during rayon fibre production;

— the basis of all chemical fibre production;

— raw material for deriving synthetic fibres;

— two groups of synthetic fibres, heterochain fibres, carbochain fibres;

— application of synthetic fibres, their properties.