The Torsional Rigidity of Wool Fibers Extended in Water

Abstract

When a wool fiber is extended in water, the concomitant values of the torsional modulus of the fiber remain relatively constant up to around 30% extension. Beyond this 30% longitudinal extension the torsional modulus of the wet wool fiber progressively increases with extension. This latter behavior, together with the observed relationship between the torsional modulus of the unextended wool fiber and the slope of the post-yield region of its longitudinal stress-strain curve, have been explained in terms of the series-zone model for keratin libers.