Heating, Cleaning, and Mechanical Processing Effects on Cotton: Part II: Equilibrium Moisture and Density

Abstract

Several series of cottons were dried by gin and laboratory methods to secure ranges in levels of drying. Moisture regain and density were determined after drying and after several types of mechanical working. The lower moisture regains for cottons excessively dried at the gin persist for long periods following drying but storage for several years essentially eliminates the influences of initial drying. Repeated exposure to high and low relative humidities at normal temperatures reduces but does not eliminate the drying effects. Cellulose density increases as lint moisture is reduced by gin drying. The changes in moisture and density suggest changes in cellulose structure but their direct influences on spinning behavior are inconclusive. Gin drying has a greater influence on moisture of cotton lint at opening and carding than in the second drawing sliver. By the latter stage, moisture differences caused by drying have been essentially eliminated, but the initial stages of mechanical processing take place when the maximum differences exist in moisture level of the lint.