Cotton—A Versatile Textile Fiber

Certain recent researches on cotton are reviewed, together with further data on natural variations of it as found on the cottonseed and modifications of the fiber by chemical and physical treatments. No attempt has been made to present a general review. A more extensive over-all treatment of cotton quality may be found in a report by the Bureau of Plant Industry [11]. Cotton fibers grow first in length, then in thickness. The physical properties of the fiber and, therefore, its use value are determined by its length, fineness, and cell-wall construc tion, all of which are genetically controlled but are also sub ject to modifications by weather conditions during growth. Since fiber length is established before the cell walls thicken, length and cell-wall structure may be influenced independ ently. As growth proceeds there is a general trend toward compensation of loss of fiber length by added strength and vice versa; however, the failure of weather conditions to remain the same throughout the growing period of the fiber may result, for example, in short, weak fiber or long, strong fiber. Cotton fibers may be modified by swelling treatments while tension is applied. Such treatments may increase the fiber strength at the expense of other properties. The spinning quality of cotton is dependent upon a com bination of fiber properties and upon the spinning technique used. In general, however, the size of yarn or thread made from cotton is dependent upon its fiber length. For a given length, fiber fineness, and even strength, may influence the maximum count to be expected. Strong yarns require relatively strong fiber for any given fiber length and fineness. Uniformity of fiber length undoubtedly influences the ease of manufacture and the percentage of waste to be expected from a given cotton, but it is indicated that well-bred mod ern varieties have sufficient length uniformity to give good results. Within a variety, however, growth conditions, gin ning, and baling may affect the fiber-length uniformity enough to influence fiber property-yarn strength relationships. Since variety characteristics may be influenced by growth conditions, causing positive varietal relationships to reverse and become negative for environment, the analyses of data consisting of fiber properties and yarn strengths, except for very general treatments, will give more information if variety and environmental effects can be segregated. It is indicated that if good certified seed of suitable varie ties for each type of environment are planted, cotton of ac ceptable quality can be produced throughout the Cotton Belt. In selecting a cotton for specialized uses, variety and growth conditions as well as grade and staple should be considered for best results.