The Theory of Shrinkproofing of Wool

Abstract

Lincoln 36's top and Merino fabric were subjected to eight different chemical treat ments, each at several levels, which included three well-known shrinkproofing treatments. The shrinkage of the treated material was compared with surface modification observed microscopically and frictional coefficients measured by the capstan method. Shrinkproofing can be brought about by a variety of chemical and physical surface treatments. The chemical composition of the surface of the treated fiber and its topography (as observed microscopically) vary according to the type of surface treat ment. There is good correlation between the amount of surface modification and the change in frictional coefficients. In agreement with the generally accepted theory of shrinkproofing, it is considered that the latter is the basic cause of shrinkproofing. This theory is adequate for most treatments but may have to be modified to account for anomalous cases such as occur on treatment with permanganate in water or on ethanol extraction.