The Effect of Relative Humidity on the Crease Recovery of Some Modified Rayon and Cotton Fabrics

Abstract

The changes in crease recovery and water absorption of untreated and modified rayon and cotton fabrics have been studied as a function of relative humidity at 25° C. The crease recovery of rayon was found to be very dependent on relative humidity and water content whereas that of cotton was almost independent. The effects of "dry"-state and "wet"-state cross-linking and other special treatments on the crease-recovery-water- content relationships were studied. All of the modified fabrics exhibited a deep minimum in crease recovery, which is attributed to the glass transition of the fibers. The minimum occurs at the water content which lowers the T, of cellulose to 25° C, the temperature of the experiment. This water content is also marked by a minimum in fiber resiliency. The change in the crease-recovery-humidity relationship produced by cross-linking gen erally parallels the change produced in the corresponding fiber resiliency relation, thereby supporting the interdependency of fiber resiliency and fabric crease recovery. The rate of crease recovery up to 5-min recovery time was determined for all the fabrics at different humidities. Over this time range, the recovery data were linearly related to log time. Although no minimum in crease recovery could be discerned for untreated rayon and cotton fabrics, the glass transition point was marked by a maximum in recovery rate.