随着塑料工业的不断发展,塑料制品应用面愈来愈广,制品尺寸的精度要求也愈来愈高。影响制品精度的因素很多。在热塑性塑料成型中,注塑的收缩现象和挤出的膨胀效应是影响制品精度的主要因素。本文根据流变学的原理,对收缩现象和膨胀效应进行了分析,得出计算收缩值 With the continuous development of the plastics industry, plastic products more and more widely used, product size accuracy requirements are getting higher and higher. Many factors affect product accuracy. In thermoforming, the shrinkage of injection molding and the expansion effect of extrusion are the main factors affecting the accuracy of the product. According to the theory of rheology, this paper analyzes the shrinkage phenomenon and the expansion effect, and draws the conclusion of calculating the shrinkage value