Calculation of shrinkage rate for injection molding based on moldflow

Abstract

During the process of injection molding, shrinkage rate varies on plastic type, product structure, processing parameter, flow gate size and location. Traditional shrinkage rate estimated from mold designer's experience makes it quite difficult to meet the accuracy requirements on products, especially in terms of big size items like automotive interior and exterior. This paper introduces the accurate calculation of shrinkage rate for injection molding by computer simulation via MOLDFLOW software, and researches the factors influencing shrinkage rate, which holds guiding significance on improving the pass rate of big size injection molded items. © Springer-Verlag 2013.