Influence of the gradient in orientation on the compressive elastic modulus and yield strength of oriented polypropylene

Abstract

The deliberate orientation of polymers is sometimes induced by the propagation of a stable neck due to uniaxial tensile loading; this has been called cold drawing. This highly anisotropic material is often used for various types of experiments. In this paper it is shown that the necked material can be quite non-uniform over the full cross section of the neck and any assumption of uniformity, as it influences subsequent findings, can be quite erroneous.