Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: January 13, 2005
Publication Date: January 13, 2005
Citation: Boykin Jr, J.C. 2005. A review of the structure of the cotton fiber and its base and potential processes to weaken the fiber-seed bond. National Cotton Council Beltwide Cotton Conference. CD ROM pp. 2690-2700. Interpretive Summary: The United States produces over 15 million bales of cotton annually. Research is continually underway to improve properties of the cotton fiber by creating higher quality cotton varieties, improving cultivation and harvesting practices, and preserving the quality of cotton as it is ginned, packaged, and transported to mills. The most important machine in the cotton gin which often causes the most damage to the cotton, is the gin stand which removes the cotton fibers from seed. Fiber length and other properties can be affected by the gin stand. In mechanically removing the fiber, the attachment force between the fiber and the seed must be overcome, and the result is often fiber breakage at less than full length. Fiber damage can be reduced by weakening the bond between the fiber and the seed with enzymes before removing the fiber. This paper reviews the structure and components of the fiber and seed important to fiber-seed attachment force, and discusses the action of enzymes that would likely alter or degrade the structure or components. The layers of the cotton fiber are the cuticle, primary wall, and secondary wall. The cuticle layer covers the entire fiber and seed and is very important in fiber processing. Weakening the fiber-seed bond will involve degrading the primary wall of the fiber in the fiber base without removing the cuticle or attacking the secondary wall, which is composed of cellulose. Enzymes such as pectinases and hemicellulases degrade components of the primary wall, but not the cuticle or secondary wall. Thus, future research will involve treating cotton with these enzymes to determine their effect on attachment force and fiber strength.
Technical Abstract: Significant cotton fiber damage can occur when overcoming the bond between the cottonseed and fiber at the gin stand. Even though the fiber-seed attachment force is typically lower than the tensile strength of the fiber, many fibers still break at less than full length. Presently available cotton physiology literature is unclear on differences in the cell wall material in the length of the fiber and in its base, especially with respect to secondary cell wall deposition in the fiber base. Any differences could be useful in understanding how to reduce fiber-seed attachment force. There was evidence that elevated moisture content may decrease fiber-seed attachment force, but contradictory reports were also found. Enzymes have been used experimentally in the past to decrease the attachment force, but they reduced the strength of the fiber. Enzymes that remove portions of the cotton fiber wall or impurities are successfully used in cotton textile research for desizing, scouring, finishing, and depilling cotton products; therefore, there is a great deal of information on the methods of treating the fiber and the effects on the fiber structure. Further research is needed to clarify the structure of the fiber related to fiber-seed attachment force and effects of enzymes, chemicals and moisture on the attachment force and fiber quality parameters.