Processing and uses of cotton

Cotton Industry
Several operations are necessary in order to prepare the raw cotton fibre, as it comes from the field, for use in the textile industry. In brief these operations are as follows: ginning, baling, transporting to the mills, picking, a process in which a removes any foreign matter and delivers the cotton in a uniform layer; overlaping, an operation whereby three layers are combined into one; carding, combing, the drawing during which the short fibres are extracted and the others are straightened and evenly distributed; and finally twisting the fibres into thread. 

Harvest and yield:
The cotton crop is usually harvested in three or four pickings, taken at suitable intervals. Picking is carried out by hand, mostly by women, the amount of cotton collected ranging from 20-50 lb per day per person. Cotton should be picked only when the bolls are fully mature, fully open and the floss has puffed up consequently on exposure to sun. Now a days a machinery are using to pick the cotton. 

Cotton marketing:
The bulk of cotton produced in India is sold as Kapas, or unginned cotton. Kapas is transported to the local markets or ginneries mainly in carts or, sometimes, on pack animals. The cultivator sells his cotton in the village market. The purchasers are village merchants, or agents of ginneries, spinning mills or exporting films. In some states, cooperative societies organized by cultivators have taken up the purchase and sale of the cotton. 

Ginning: 
Kapas Or seed cotton collected from the field contains both lint and seed. For use in Industry, cotton should be cleaned and the lint separated from seed. A small amount of seed cotton is ginned in village by the use of charka gin. The bulk of it, however, is ginned in factories by power driven machinery. The yield and quality of lint depend on the type of cotton and the machinery used for ginning. 

Baling:
Cotton is packed for trade purposes both in loose and compressed bales. Loose packing is adopted for inland transit of ginned cotton to a pressing factory, while compressed packing is adopted for transporting ginned cotton to the market and for storing in the godowns. Each loose bale contains 200 to 300 lb of cotton. The usual weight of compressed bale is 392 lb net with a density of 40 lb per cubic foot. 

Uses of cotton:
The bulk of cotton production is consumed in the manufacture of woven goods, alone or in combination with other fibres. The principal types of woven fabrics are print cloths, yarn fabrics, sheetings, fine cotton goods, napped fabrics, duck, tyre fabrics and towels. Products in the form of yarn or cord include inwoven tyre cord, thread, cordage and twine and crochet yarns. Unspun cotton finds use in mattresses, pads and upholstreries. Cotton constitutes, one of the basic raw materials for cellulose industries including plastics, rayon and explosives. Sterilized absorbent cotton finds use in medical and surgical practice. 

Yarn of varying size and fineness are needed in the production of fabrics. Coarse yarns are spun from short staple cottons and fine ones from medium and long staple types. Long and uniform staples are utilised for yarns of high counts required for fine fabrics. 

Cotton waste is a by product of the spinning and weaving mills and consists principally of short fibres rejected by combing and carding, machines, floor sweepings, odds and ends from weaving and various scraps. The amount of waste given by cotton is an important factor in its quality evaluation. Cotton waste of good grade is employed in making cotton blanket, sheets, towels and flannelettes. Cotton waste of good grade is employed in making cotton blanket, sheets, towels and flannelettes. Cylindrical strips from carding machines, which are constiruted of fibres ofz good strength, are used for warps, twines, ropes and nets; they are also useful for warps, padding, for upholstrey, bed quilts, etc. Strips from Egyptian cottons are mixed with wool for making mixed woollen goods. Floor sweepings and fibres unfit for spinning are bleached and used for gun cotton, cellulose and artificial silk. Short remnants and thread waste that cannot be respun are used as wiping and polishing materials. 

The stalks of plant contain a fibre that can be used in paper making or for fuel, and the roots possess a crude drug. The seeds are of the greatest importance and every portion is utilised. The hills are used for stock feed; as fertilizer; for lining oil wells; as a source of xylose, a sugar that can be converted into alcohol and for many other purposes. The kernals yield one of the most important fatty oils, cottonseed oil and cake and meal which are used for fertilizer, stock feed, flour, and as a dyestuff. 
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