Measuring the Residual Stress of the Injection Moulded Polymeric Parts

Abstract

The residual stresses are usually introduced during manufacturing, and are caused by processes such as molding. This paper presents how the authors determine the residual stresses for the flat plates from ABS, PP and PS for an optimum injection process. In order to optimize injection molding process with polymeric material, it is important to predict the internal stress development during molding. The authors determine it with the most widely used practical technique for measuring residual stresses, the hole-drilling strain gauge method described in ASTM Standard E837. With this method, a specially configured electrical resistance strain gauge rosette is bonded to the surface of the test object.