Cotton Quality and Fiber Properties

Abstract

The purpose of this research was to evaluate the use of single-fiber testing methods for the determination of cotton fiber properties and for the prediction of yarn quality. Samples of unprocessed cotton, finisher drawing sliver, and 36's carded yarn were ob tained for 21 domestic cotton varieties representing extremes in length, fineness, and strength. Single fibers from all three processing stations were tested for their fineness and mechanical properties: crimp, Hookean slope, breaking load, elongation, elastic modulus, breaking stress, and energy to rupture. Ranges for each of these properties were established. The results were compared with the mechanical properties of the fiber bundles, slivers, and yarns. Correlation studies of the results show that all of the mechanical properties measured on fibers are related to fiber fineness and, among the varieties, to fiber length. Bundle strengths and elongations at clamp spacings greater than 1.5 mm. relate well to fiber breaking strengths and elongations. Sliver force-extension slope is dependent on fiber fineness and fiber elastic modulus. Yarn strength depends strongly on fiber length, fine ness, and elastic modulus, and only weakly on fiber strength; yarn elongation depends greatly on fiber elongation and elastic modulus. These observations suggest that yarn strength and elongation are related to the single fiber properties and can be predicted from them fully as well as from bulk measurements of fineness and bundle strength data. They also indicate that elastic modulus is an im portant parameter for predicting fiber assembly behavior.