43—The Extension of Wool Fibres under Constant Stress

Abstract

The present investigation has confirmed the views expressed in a previous paper concerning the gel structure of the wool fibre. The existence of a definite yield point has been demonstrated and the occurrence of a second point of inflexion on the stressstrain diagram for wool shown to be independent of the rate of loading. Andrade’s expression for the rate of extension of metal wires under constant stress has been shown to apply equally well to wool fibres, and data have been given enabling one to calculate the extension and rate of extension of English Cotswold wool at 15° C. in saturated air under any stress. Finally, the existence of a gelatinous phase in the wool fibre has been confirmed. It has been shown to vary in composition from one wool to another and to change in viscosity with temperature. The investigations are being continued on the lines suggested.