|Griffin Jr, A. - RETIRED ARS USDA|
Submitted to: Cotton Gin and Oil Mill Press
Publication Type: Popular Publication
Publication Acceptance Date: November 17, 2001
Publication Date: November 17, 2001
Citation: Anthony, W.S., Griffin Jr, A.C. 2001. Fiber breakage at gins: moisture and heat. Cotton Gin and Oil Mill Press. Vol. 102(23): 10-15 and 102(24): 6-9 Interpretive Summary: Fiber breakage during the ginning (fiber-seed separation) process has historically been a problem at cotton gins. One of the possible causatives is fiber drying that results in molecular and fibrillar reorientation that distorts the fiber. Eight studies were conducted to better understand the nature and causes of fiber breakage at gins. The studies considered the force to remove single fibers from the seed, the force required to break single fibers, the impact of temperature and moisture on ginning, the addition of moisture before ginning, and the impact of several pre-cleaning machines. The results showed that fibers must not be exposed to temperatures above 300 degrees F and should be separated from the seed at moisture between 6.5 and 8%. Adherence to these two principles will increase fiber length and length uniformity, and improve the competitiveness of cotton in the global textile market.
Technical Abstract: The causatives and potential solutions to fiber breakage at cotton gins was considered in eight studies which included both single fiber and bulk fiber evaluations. The following findings were the most important across the studies: 1)the force required to break the fiber averaged 1.8 times greater than the force to extract it from the seedcoat but this difference was non-linear and was less at low moisture and more at high moisture contents, 2)during field exposure, fiber breaking strength declines more rapidly than fiber separation force, 3)fiber exposure to temperature above 350 degrees F causes irreversible fiber damage, 4)the adverse effect of fiber exposure to temperatures less than 300 degrees F can be mitigated by the addition of moisture before ginning, 5)when fiber moisture increases one percentage point, fiber breakage decreases 0.5 percentage points, and 6)fiber breakage is much greater at 350 degrees F than at 300 degrees F, and 7)fiber length is reduced at a particular moisture content as drying temperature increases.