Technology ("science of craft", from Greek τέχνη, techne, "art, skill, cunning of hand"; and -λογία, -logia[2]) is the sum of techniques, skills, methods

Cotton fibres
M. Dochia, ... Z. Roskwitalski, in Handbook of Natural Fibres: Types, Properties and Factors Affecting Breeding and Cultivation
Cotton fibre structure
Cotton fibres have a multilayered structure that has been studied for nearly a century. The structure of the primary cell wall of the cotton fibre, and particularly the outer surface layer has a major influence on fibre properties, processing and use. Cotton fibre has a fibrillar structure which consists of a primary wall, a secondary wall and a lumen The typical components of dry mature cotton fibres are shown in Figs 2.2 and 2.3. Most of the non-cellulosic materials are present in the outer layers of cotton fibre.

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2.1. Structure of cotton^9,10

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 A schematic representation of mature cotton fibre showing its various layer. Cross section of cotton fibre. Typical components in dry, mature cotton fibres and compositions of each layer. Morphological model of cotton fibre.

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 A schematic representation of the cellulosic and non-cellulosic materials in the cotton fibre.
Under a microscope a cotton fibre looks like a twisted ribbon or a collapsed and twisted tube These twists are called convolutions: there are about 60 convolutions per centimetre. The convolutions give cotton an uneven fibre surface, which increases inter-fibre friction and enables fine cotton yarns of adequate strength to be spun. The cross-section of a cotton fibre is often described as being kidney-shaped. Figure 2.5 shows scanning electron microscopy images of different layers in the figure. The outermost layer, the cuticle is a thin film of mostly fats and waxes. Figure 2.5b shows the waxy layer surface with some smooth grooves. The waxy layer forms a thin sheet over the primary wall that forms grooves on the cotton surface. The primary wall Fig. 2.5c comprises non-cellulosic materials and amorphous cellulose in which the fibrils are arranged in a criss-cross pattern. Owing to the non-structured orientation of cellulose and non-cellulosic materials, the primary wall surface is unorganized and open. This gives flexibility to the primary wall, which is required during cell growth. The basic ingredients responsible for the complicated interconnections in the primary wall are cellulose, hemicelluloses, pectins, proteins and ions. The secondary wall, in which only crystalline cellulose is present, is highly ordered and has a compact structure with the cellulose fibrils lying parallel to one another Fig. 2.5d

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2.4. The appearance of cotton fibre under the microscope. Cotton fibre looking like a twisted ribbon; the cotton fibre’s cross section is referred to as being kidney-shaped cotton fibre looking like a collapsed and twisted tube and bundle of cotton fibres.

QUESTIONS:
1.What is cotton fiber?
2.What fibers are in cotton?
3.What are the main properties of cotton Fibers?
4.What are the five properties of cotton?

5.Why is cotton fiber a polymer?

6.How cotton goes from a plant to fiber?
7.Do people want to dig a little dipper?
Tests
1. Is there anything in that new magazine worth ... ?
A. to read
B. reading
2. Although I was in a hurry, I stopped... to him.
A. to talk
B. talking
3. I really must stop ... .
A. to smoke
B. smoking
4. Would you mind... the front door?
A. to close
B. closing
5. You should remember ... him. He’ll be at home.
A. to phone
B. phoning
6. All parts of London seem... to different towns and epochs.
A. to belong
B. belonging
7. Do you enjoy ... ?
A. to teach
B. teaching
8. Why have you stopped? Go on ... .
A. to read
B .reading