Table of Contents
Chapter 1 – Textile Manufacturing
Chapter 2 – Dref Friction Spinning
Chapter 3 – Textile
Chapter 4 – Units of Textile Measurement
Chapter 5 – Textile Manufacture during the Industrial Revolution
Chapter 6 – Spinning (Textiles)
Chapter 7 – Weaving
Chapter 8 – Textile Bleaching and Dyeing
Chapter 9 – Textile Printing
Textile manufacturing is a major industry. It is based in the conversion of three types of fibre into yarn, then fabric, then textiles. These are then fabricated into clothes or other artifacts. Cotton remains the most important natural fibre, so is treated in depth. There are many variable processes available at the spinning and fabric-forming stages coupled with the complexities of the finishing and colouration processes to the production of a wide ranges of products. There remains a large industry that uses hand techniques to achieve the same results.
Cotton is the world’s most important natural fibre. In the year 2007, the global yield was 25 million tons from 35 million hectares cultivated in more than 50 countries.
There are five stages
- Cultivating and Harvesting
- Preparatory Processes
Cultivating and harvesting
Cotton is grown anywhere with long, hot dry summers with plenty of sunshine and low humidity. Indian cotton, gossypium arboreum, is finer but the staple is only suitable for hand processing. American cotton, gossypium hirsutum, produces the longer staple needed for machine production. Planting is from September to mid November and the crop is harvested between March and May. The cotton bolls are harvested by stripper harvesters and spindle pickers, that remove the entire boll from the plant. The cotton boll is the seed pod of the cotton plant, attached to each of the thousands of seeds are fibres about 2.5 cm long.
The seed cotton goes in to a Cotton gin. The cotton gin separates seeds and removes the “trash” (dirt, stems and leaves) from the fibre. In a saw gin, circular saws grab the fibre and pull it through a grating that is too narrow for the seeds to pass. A roller gin is used with longer staple cotton. Here a leather roller captures the cotton. A knife blade, set close to the roller, detaches the seeds by drawing them through teeth in circular saws and revolving brushes which clean them away.
The ginned cotton fibre, known as lint, is then compressed into bales which are about 1.5 m tall and weigh almost 220 kg. Only 33% of the crop is usable lint. Commercial cotton is priced by quality, and that broadly relates to the average length of the staple, and the variety of the plant. Longer staple cotton (2½ in to 1¼ in) is called Egyptian, medium staple (1¼ in to ¾ in) is called American upland and short staple (less than ¾ in) is called Indian.
The cotton seed is pressed into a cooking oil. The husks and meal are processed into animal feed, and the stems into paper.
Cotton is farmed intensively and uses large amounts of fertiliser and 25% of the worlds insecticide. Native Indian variety were rainwater fed, but modern hybrids used for the mills need irrigation, which spreads pests. The 5% of cotton-bearing land in India uses 55% of all pesticides used in India. Before mechanisation, cotton was harvested manually and this unpleasant task was done by the lower castes, and in the United States by slaves of African origin.
Preparatory processes- preparation of yarn
- Ginning, bale-making and transportation is done in the country of origin.
- Opening and cleaning
Cotton mills get the cotton shipped to them in large, 500 pound bales. When the cotton comes out of a bale, it is all packed together and still contains vegetable matter. The bale is broken open using a machine with large spikes. It is called an Opener.In order to fluff up the cotton and remove the vegetable matter, the cotton is sent through a picker, or similar machines. A picker looks similar to the carding machine and the cotton gin, but is slightly different. The cotton is fed into the machine and gets beaten with a beater bar, to loosen it up. It is fed through various rollers, which serve to remove the vegetable matter. The cotton, aided by fans, then collects on a screen and gets fed through more rollers till it emerges as a continuous soft fleecy sheet, known as a lap.
Blending, Mixing & Scutching
Scutching refers to the process of cleaning cotton of its seeds and other impurities. A scutching machine for cotton was first invented in 1797, but didn’t get much attention until it was introduced in Manchester in 1808 or 1809. By 1816 it had been generally adopted. The scutching machne worked by passing the cotton through a pair of rollers, and then striking it with iron or steel bars called beaters. The beaters, which turn very quickly, strike the cotton hard and knock the seeds out. This process is done over a series of parallel bars so as to allow the seeds to fall through. At the same time a breeze is blown across the bars, which carries the cotton into a cotton chamber.