Relaxation Shrinkage of Worsted Yarns

Abstract

The relaxation shrinkage of yarns spun on the Ambler Super Draft and double-apron systems has been examined. The effects of spinning-frame settings, fiber diameter, additives, and treatments have all been assessed, as well as the contribution made by folding and winding. With the Ambler Super Draft system it was found that all of the factors had some effect upon yarn shrinkage, these effects being approximately additive. Tension-roller weighting had by far the greatest effects; it alone could give a variation in yarn shrinkage of 10%. With the double-apron system the effect of all of the factors was much less, a consistently low shrinkage being obtained. Autoclaving as a method of stabilizing yarn shrinkage was found to be effective only for low-shrinkage yarns.