Bending Rigidity and Hysteresis of Wool Worsted Yarn

Abstract

The bending rigidity of wool worsted yams was estimated from the mean fiber diameter together with four correction factors due to fiber diameter distribution, yam twist, fiber ellipticity, and mean fiber length. The first two correction factors were the most important. The bending hysteresis (the coercive couple) increases as the maximum curvature attained in a cyclic bending test increases. This is only partly due to the viscoelasticity of wool fibers. It is possible that the frictional couple has a viscoelastic component as well.