Cotton Ginning

Cotton gins are machines used to separate cotton fibers from cotton seeds, a process that must be done before cotton fibers can be used for textiles. High quality cotton is the combined result of the original characteristics of the fiber and the degree of cleaning and drying it receives. The amount of trash and moisture in the cotton helps to determine the efficiency of the overall ginning process.

In 2009, cotton gins in the United States produced about 12.2 million bales of cotton, compared to 12.8 million bales in 2008 and 14.4 million bales in 2002. Low labor costs in countries such as China and Brazil allowed global cotton producers to flood the U.S. market with inexpensive cotton in the early years of the first decade of the 2000s. U.S. imports of cotton grew by 5 million bales between 1997 and 2001. By the early 2010s, however, U.S. exports of cotton, especially to China and other Asian countries, were on the rise. For example, in June 2010, the United States exported 624,000 bales of cotton in one week; China accounted for 85 percent of the exports. The same year, however, trade with Brazil was disrupted when the country won a case filed with the World Trade Organization that claimed that U.S. cotton subsidies had negatively affected Brazilian cotton growers. As of mid-2010, the two countries were working on an agreement that would rectify the situation through measures written into the 2012 Farm Bill.

In the first decade of the 2000s, some establishments operated a single gin, while larger companies had several. Texas and Georgia were the leading cotton-producing states, with 4.7 million bales and 1.8 million bales, respectively, in 2009. Arkansas and North Carolina were also important states in this industry, with about 820,000 bales and 780,000 bales, respectively. Together these four states accounted for approximately 67 percent of all cotton ginned in the United States in the late years of the first decade of the 2000s. Other states that contributed less significantly included California (608,000 bales), Missouri (535,000 bales), Tennessee (498,000 bales), Arizona (438,000 bales), and Mississippi (406,000 bales). The average net weight per bale remained fairly steady late into the decade at about 493 pounds.

Industry leaders in the early 2010s included Anderson Clayton Corporation of Fresno, California. Owned by Australia-based Queensland Cotton Holdings Ltd., Anderson Clayton operated 13 gins in the United States. Lyford Gin Association of Lyford, Texas, operated two gins that together produced up to 1,000 bales a day during the cotton season.

Eli Whitney, a schoolteacher from Massachusetts, is generally given credit for inventing the first cotton gin in 1773. Whitney's gin, which he patented in 1774, was actually an improvement on an earlier invention known as the Churka gin. The Churka gin used rollers to loosen the cotton fibers, but it was almost useless on the tight, fuzzy variety of cotton that was grown in the Southern states. Whitney replaced the rollers with revolving wooden spikes that pulled the fibers down narrow slots, through which the seeds could not fall. A brush would then clean the cotton from the spikes. The hand-cranked Whitney gin drastically improved the pace of cotton cleaning and made cotton a profitable crop for Southern farmers.

Hodgen Holmes, a mechanic who had worked for Whitney, further improved the cotton gin by replacing the spikes with saw-toothed metal cylinders, which were more effective in grabbing hold of the cotton fibers. Holmes, who received a patent on his gin in 1776, also opened up the bottom of his gin so cotton could be fed into the top of the machine in a continuous process. Mechanical cleaners were added to the basic cotton gin in the 1840s to remove the leaves and stems left by harvesting. The first drier to reduce the moisture content of the cotton before ginning was patented in 1929.

Although the basic technology developed by Whitney and Holmes has remained in use, modern gins have become much more complex. In the early 1960s, cotton ginners developed an improved version of the Churka roller gin for use on long-fiber Pima cotton grown in the Southwest. These roller gins used two knife blades, one revolving and one stationary, to separate the cotton from the seeds. Pima cotton accounted for about 5 percent of the cotton grown in the United States.

Many ginners also sold or processed cottonseed for additional revenue. According to the National Cotton Council of America, more than 5 billion pounds of cottonseed and cottonseed meal were used annually for feeding livestock. Another 100 million gallons of cottonseed oil were used in food products. In the late 1980s, more ginners also began to offer compressing and warehouse services.

Until the 1990s, all ginned cotton received the same treatment, without regard to its trash content or its quality. Cotton ginning is a voluminous and complex procedure, which makes it impossible for humans to visually measure or decipher the amount of trash in the cotton or the quality of it; however, new technological advances have improved this situation.

Computerized advancements, for example, now make it possible to monitor and evaluate the ginning process online, as well as evaluate the response of cotton fiber during the process. These new technological advances accurately measure each component of the ginning process and allow the ginner to process various types of cotton through the minimum machinery necessary to obtain maximum returns while keeping the fiber quality intact.

In 1929, the Department of Agriculture (USDA) established the U.S. Cotton Ginning Research Laboratory in Stoneville, Mississippi. The research laboratory has received several public service patents for developments that have improved cotton ginning. Other research facilities established by the USDA include the Cotton Production and Processing Research Unit in Lubbock, Texas, and the Southwestern Cotton Ginning Research Lab in Mesilla Park, New Mexico. In 1938, the National Cotton Ginners' Association, located in Memphis, Tennessee, was chartered to provide a national voice for several state and regional associations. The association conducts a gin safety program, disseminates information on technology, and acts as a liaison between the ginning industry and machinery manufacturers. It also tracks federal legislation that affects the industry, including proposals affecting occupational health and safety, migrant workers, and clean-air regulations.

The effects of cotton processing on human health have been well documented by the National Cotton Ginners' Association and the U.S. Department of Labor. The evidence indicates that the dust from cotton processing may be hazardous to a person's health. Many contaminants have been identified that could cause serious respiratory diseases. Because of these dangers, employers are required to limit the level of breathable cotton dust in the air and take other safety measures, such as supplying employees with respirators, periodic medical examinations, and training programs. In the early years of the first decade of the 2000s, the USDA began studying new uses for cotton gin waste, such as a mulch product that combined ryegrass seed with cotton waste. Research efforts in the early 2010s continued to focus on reducing cotton ginning's "environmental footprint" as well as improving efficiency and quality.