Editing Cotton gin (section)

==Modern cotton gins==
[[Image:ginplant.jpg|thumb|left|Diagram of a modern cotton gin plant, displaying numerous stages of production]]
[[File:Cotton jins in use.jpg|thumb|right|Modern cotton gins]]
In modern cotton production, cotton arrives at industrial cotton gins either in trailers, in compressed rectangular "[[cotton module builder|modules]]" weighing up to 10 [[metric ton]]s each or in polyethylene wrapped round modules similar to a bale of hay produced during the picking process by the most recent generation of cotton pickers. Trailer cotton (i.e. cotton not compressed into modules) arriving at the gin is sucked in via a pipe, approximately {{convert|16|in|cm}} in diameter, that is swung over the cotton. This pipe is usually manually operated but is increasingly automated in modern cotton plants. The need for trailers to haul the product to the gin has been drastically reduced since the introduction of modules. If the cotton is shipped in modules, the module feeder breaks the modules apart using spiked rollers and extracts the largest pieces of foreign material from the cotton. The module feeder's loose cotton is then sucked into the same starting point as the trailer cotton.

The cotton then enters a dryer, which removes excess moisture. The cylinder cleaner uses six or seven rotating, spiked cylinders to break up large clumps of cotton.  Finer foreign material, such as soil and leaves, passes through rods or screens for removal.  The stick machine uses [[centrifugal force]] to remove larger foreign matter, such as sticks and burrs, while the cotton is held by rapidly rotating saw cylinders.

[[image:Ginstand.jpg |thumb |300px |The internals of a cotton gin]]

The gin stand uses the teeth of rotating saws to pull the cotton through a series of "ginning ribs", which pull the fibers from the seeds which are too large to pass through the ribs. The cleaned seed is then removed from the gin via an [[auger conveyor]] system. The seed is reused for planting or is sent to an [[oil mill]] to be further processed into [[cottonseed oil]] and [[cottonseed meal]]. The lint cleaners again use saws and grid bars, this time to separate immature seeds and any remaining foreign matter from the fibers. The bale press then compresses the cotton into bales for storage and shipping. Modern gins can process up to {{convert|15|t|lb}} of cotton per hour.<ref>{{Cite web|title=Page 3 : USDA ARS|url=https://www.ars.usda.gov/southeast-area/stoneville-ms/cotton-ginning-research/docs/overview-of-a-cotton-gin/page-3/|access-date=2021-11-25|website=www.ars.usda.gov}}</ref>

Modern cotton gins create a substantial amount of cotton gin residue (CGR) consisting of sticks, leaves, dirt, immature bolls, and cottonseed. Research is currently under way to investigate the use of this waste in producing [[ethanol]]. Due to fluctuations in the chemical composition in processing, there is difficulty in creating a consistent ethanol process, but there is potential to further maximize the utilization of waste in cotton production.<ref>{{cite book|title=Biotechnology for Fuels and Chemicals|first1=Foster A.|last1=Agblevor|first2=Sandra|last2=Batz|first3=Jessica|last3=Trumbo|date=February 3, 2018|publisher=Humana Press, Totowa, NJ|pages=219–230|doi=10.1007/978-1-4612-0057-4_17|chapter = Composition and Ethanol Production Potential of Cotton Gin Residues|isbn = 978-1-4612-6592-4}}</ref><ref name=AboutGin/>