Saw gins

FIGURE 1.6 Cotton gin stand, saw-ginning process. (Courtesy of the National Cotton Council of America, Memphis, TN.)... 

Saw-ginned cottons (Upland cottons) are classed on a different system than roller-ginned cottons (longer-staple fibers and the very short Asiatic desi cottons). 

After the harvest, the seeded cotton is ginned. The number of cleaning stages necessary depends on the condition of the raw cotton still containing the seeds. The cleaning is done with regular beaters, like those used by spinning preparation machinery. There are two kinds of machines the saw gin and the roller gin. 

The saw gin is more economical because its mechanization and automation is more advanced. Thus, it is the preferred processing method at present. 

It is said that Alexander the Great introduced Indian cotton into Egypt in the fourth century BC, and from there it spread to Greece, Italy, and Spain. During the year AD 700, China began growing cotton as a decorative plant, and AD 798 saw its introduction into Japan. Early explorers in Pern found cotton cloth on exhumed mummies that dated to 200 BC. Cotton was found in North America by Columbus in 1492. About 300 years later, the first cotton mill was built in Beverly, Massachusetts, and in 1794 EH Whitney was granted a patent for the invention of the cotton gin. 

After cotton has been harvested, the seeds must be removed. Essentially the same method devised by Whitney in 1793 is used. The seed cotton is fed into a gin consisting of a series of circular saws that separate the fiber from the seeds. The fiber is then compressed into bales weighing about 478 lb (217 kg). A second ginning separates out the short fibers leaving the more desirable longer fibers. 

Rotary Ki 1 n Non-Catalytic Low Pressure No Oxygen Required 0.5 ODT/D laboratory unit at Fayettevilie 28 ODT/D PDU at Jonesboro Arkansas Wood Chips, Saw Dust, Rice Hulls, Cotton Gin Thrash, Nut Hulls, and Other Agricultural Resi dues Low BTU gas and char Small industrial and agricultural applications Operational... 

Af ter I had been given some gin to quiet my nerves, my fellow-prisoners were also told the news. By the end of a long evening of discussion, attempts at explanation, and self-reproaches I was so agitated that Max von Laue and the others became seriously concerned on my behalf. They ceased worrying only at two o clock in the morning, when they saw that I was asleep. 

Mechanical harvesting systems were made possible by the invention of saw-type lint-cleaning systems in the early 1950s. Lint cleaners enabled gins to remove from the cotton the additional trash that resulted from mechanical harvesting. The mechanical systems reduced the harvesting period from 4-5 months to 6-8 weeks of intensive operation. Severe congestion problems at the gin were eased... 

The seed hairs, called lint, are removed by saw-like machines (gins). Slots in the machine allow lint to pass and keep the seed back. Modem gins are multifunctional that also dry, blend and clean the lint and the seed. Packing of the long cotton fibers into bales of 220 kg follows. The seed, 65% by weight and 15% by value, is source of ->cottonseed oil and cotton linters (->cellulose). 

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