Shrink-Resist Treatment and Laundering of Wool Fabrics

Abstract

Commercial wool fabrics may shrink on wetting, due to the relaxation of strains imparted in processing, in washing, due to felting, an inherent property of wool fiber. and in the tumble drying- of wet fabrics, due to a reversible relaxation of structure. The common industrial methods for reducing felting by chemical reactions are described. Many factors affect the rates of these reactions, and it is essential to control the proc esses adequately if shrink resistance of the required level is to be consistently obtained. The types of machines used for treatment and the importance of efficient scouring and of obtaining level treatments are discussed. The properties of wool treated by the various methods are described. It is often better to dye or bleach after shrink-resist treatment, but it is shown that prolonged boiling must be avoided since shrink resistance and strength may be adversely affected and relatively high weight losses obtained. Machine laundering of woven and knitted fabrics is discussed in terms of type of machine action, load in the machine, fabric structure, and degree of shrink-resist treat ment. All these factors must be considered simultaneously in the commercial production and sale of washable wool goods.