Submitted to: Cotton Gin and Oil Mill Press
Publication Type: Trade Journal
Publication Acceptance Date: August 20, 2004
Publication Date: September 4, 2004
Citation: Valco, T.D., Anthony, W.S., Byler, R.K., Pelletier, M.G., Hughs, S.E., Norman, W.M. Moisture restoration of cotton. Cotton Gin and Oil Mill Press, September 4, 2004 pp5-8.
Cotton moisture content is a critical factor affecting cotton cleaning, handling, and fiber quality preservation at the gin. Cotton with too high a moisture content will not easily separate into single locks, but will form wads that may choke and damage gin machinery or entirely stop the ginning process. Cotton with too low a moisture content may stick to metal surfaces as a result of static electricity generated on the fibers and cause machinery to choke and stop. Fiber dried and processed at low moisture content is more brittle and easily damaged by the mechanical actions required for cleaning and ginning. When pressing and baling low moisture cotton, hydraulic pressure dramatically increases causing excessive equipment wear and problems with bale tie breakage escalate.
The effort required to measure and control moisture will pay dividends in gin operation efficiency and market value of the cotton. Research has shown moisture contents for seed cotton cleaning and ginning cotton is best at 6 to 7 percent moisture content (wet basis), which allows for sufficient cleaning with minimal fiber damage. Bale packaging at these moisture contents minimizes press force, static, and bale-tie breakage. Cotton with fiber moisture greater than 8 percent will not clean and/or smooth out properly when processed through the lint cleaners and bale storage at moisture contents greater than 8 percent can cause degradation to the fiber color during long term storage. The National Cotton Council recommends 7.5 percent (wet basis) as the maximum moisture level for cotton bales, until such time as more research further refines this number.