Relaxation Shrinkage of Worsted Yarns

Abstract

This account provides information about the cause of relaxation shrinkage in worsted yams, and in particular it examines the contribution which cohesive set in single fibers makes to yarn shrinkage.It is shown that yam shrinkage can be a significant factor in the relaxation shrinkage exhibited by both woven and knitted fabrics. It can give rise to such problems as "bubbling" in checks and variability of dimensions of knitteds. There is also good evidence to show that yam shrinkage can be the cause of fabric expansion during washing.The conditions which should be used for measurement of yam shrinkage are discussed, and it appears that a tension of 0.2 gf/tex is appropriate in many cases. '