Hygral Expansion of Woven Wool Fabrics

Abstract

An experimental study is reported of the hygral expansion behavior of a wide range of laboratory produced and some commercially produced wool woven outerwear fabrics. A fabric hygral expansion apparatus simultaneously measures changes in fabric length and fabric moisture regain which occur when the relative humidity of the ambient environment is altered. Fabric and yam hygral expansion curves are analyzed and discussed in terms of the following parameters: hygral expansion coefficient (slope of the initial linear part of the hygral expansion versus moisture regain curve), hygral expansion at 25% regain, and hygral expansion at 30% moisture regain. F bric hygral expansion behavior depends largely on the magnitude of the weave crimp. The effect of weave construction on the fabric hygral expansion is very small at high moisture regains; at low regains, plain-weave fabrics tend to show slightly higher expansion than the corresponding twill structures of similar crimp magnitude. The effect of fiber properties on hygral expansion behavior has been examined for a series of wool plain-weave fabrics produced from yams of the same linear density.