Properties of Wool Fibers Heated to Temperatures Above 100°C

Abstract

The heating of wool fibers in. the presence of water vapor induces changes in the physical properties of the fibers. For thermal treatments over relatively short periods degradation is minimized and the observed properties indicate a strength ening of the fibers. Continued heating causes degradation, which becomes more severe with increasing water content, and a concomitant weakening of the fibers. The data obtained on thermal stability, tensile properties, and moisture relations of heat-treated wool indicate a simultaneous degradation and reorganization of the keratin structure. The reorganization causing strengthening is predominantly associated with the matrix regions of the fibers, and some of the change is stable to saturation with water. A network of secondary bonds, which is not stable to wetting out in water, is also formed. The presence or absence of air during heating leads to significant differences in fiber properties which become more pro nounced at higher temperatures.