Stress relaxation behavior of binary mixtures of waxes.

Abstract

Stress relaxation contributes greatly to the restriction of shrinkage of the pattern at the male portion of the die. In this study, three types of binary mixtures consisting of paraffin and another ingredient were formulated, and the effects of ingredients on stress relaxation of these mixtures were investigated.By the application of the time-temperature superposition principle for each material, relaxation curves at various temperatures were superimposed to a single master curve with good overlapping. Addition of carnauba wax to paraffin resulted in a high restriction of stress relaxation in the high temperature range. Addition of beeswax to paraffin decreased the modulus of mixtures in the low temperature range. Dammar caused no appreciable change in stress relaxation of mixtures.