48—A Helical Spring Model for the Uncrimping of Wool Fibres

Abstract

A helical spring is proposed as a model to represent the load vs. extension behaviour of a wool fibre in uncrimping. The theoretical relationship deduced is similar in form to an approximate expression derived by G. W. Walls for the high load region of decrimping, based on a detailed study of actual crimp forms. Moreover, it is found to be in good agreement with the form of relationship found experimentally for a range from low to high decrimping loads. The theoretical relationship can be represented with reasonable accuracy by a much simpler empirical equation previously determined experimentally, and permits a physical interpretation to be given to the empirical parameters.