Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 13, 2007
Publication Date: October 1, 2007
Citation: Whitelock, D.P., Armijo, C.B., Gamble, G.R., Hughs, S.E. 2007. Survey of seed-cotton and lint cleaning equipment in US roller gins. Journal of Cotton Science. 11:128-140. Interpretive Summary: Pima cotton, an extra-long-staple cotton, is roller ginned to preserve its high quality. The US roller ginning industry has changed since 1989. The majority of gins have shifted from Arizona to California. The number of gins in the US has also fallen by nearly 50%, but those operating today process cotton at nearly twice the rate. A survey of the US roller gins was conducted to document current roller ginning practices, identify the types and sequences of cotton cleaning equipment, and assess the effectiveness of the cleaning equipment. There were very few similarities among gins in machinery set-ups for cleaning seed-cotton before ginning. There were more similarities among gins in machinery for cleaning ginned fiber. The trend in roller ginning today is toward aggressive cleaning before ginning and gentler cleaning after ginning to preserve cotton quality. Cotton property measurements showed that, in general, cleaning machines are doing the job they are intended to do. Cleaning after ginning increased cotton lint value by about $12.50 per bale. No definite recommendations for foreign matter removal at US roller gins could be made. The need for evaluations of individual cleaning machines in a laboratory gin plant was revealed. This information will aid researchers in planning and focusing future work to improve Pima cotton quality coming from US gins.
Technical Abstract: Pima cotton is roller ginned to minimize damage to the fiber. The US roller ginning industry has changed since 1989. The majority of gins have shifted from Arizona to California. The number of gins in the US has also fallen by nearly 50%, but those operating today have more gin stands and process cotton at nearly twice the rate. A survey was conducted to better understand how current foreign matter removal practices affect Pima cotton quality. There were very few similarities in machinery set-up for seed-cotton cleaning among gins. Most gins use one or two cylinder cleaners and an air-type lint cleaner for lint cleaning. The trend in roller ginning today is toward aggressive seed-cotton cleaning and gentle lint cleaning to limit fiber damage. Cotton property measurements taken before and after cleaning showed that, in general, cleaning machinery reduced foreign matter content in seed cotton and lint. Also, cleaning machines tended to reduce fiber length and increase neps. There was an average increase in lint value from 1.66 to 1.72 $/kg (75.5 to 78.1 ¢/lb) due to lint cleaning. This increase could not be attributed to any one type of lint-cleaning machine. No definite recommendations for foreign matter removal at US roller gins could be made, but the results emphasized the need for controlled evaluations of individual cleaning machines.