The effect of hot and cold rolling on the properties of poly(oxymethylene)

Abstract

Poly(oxymethylene) was rolled uniaxially and biaxially to varying thickness reductions at ambient and 77 and 127°C. The tensile properties of the rolled and unrolled materials were measured both in the longitudinal and transverse directions under room temperature conditions. It is found that, as a result of rolling, the tensile strength and percent elongation of the material are considerably increased in the rolling direction, with little or no appreciable effect in the transverse direction. Wide-angle X-ray diffraction studies revealed that the preferred orientation of material during rolling takes place largely in the rolling direction and partially in the transverse direction. The rolling temperature does not seem to have any significant effect upon the preferred orientation and mechanical properties, but it affects slightly the limiting thickness reduction due to rolling. The changes in the density and mechanical properties resulting from rolling seem to be related to the morphological changes occurring in the material during the rolling process. © 1975 The Society of Polymer Science, Japan.