Set/Supercontraction Characteristics and Longitudinal Swelling of Keratin Fibers

Abstract

The longitudinal swelling of three different sorts of wools, when permanently set, has been studied. It has been observed that, when progressively set, Mohair fibers, which acquire a set much more readily, show retarded swelling, compared to Blackface wool fibers. The effect of setting time reveals that the structure of Mohair fiber opens up at a much faster rate, but the swelling is high in the case of Blackface wool fiber which exhibits poor settability. Moreover, in each case, fibers, on acquiring a certain set, show a decrease in longitudinal swelling due to bond re-formation. It appears that the increase in longitudinal swelling, which is due to changes in the cortical regions, is influenced not only by the setting strain or the setting time; the number of strained bonds initially present and the ease of bond re-formation also determine the extent of swelling.