微孔发泡注射成型与传统注射成型的对比分析

通过微孔发泡注射成型和传统注射成型定量对比分析，系统分析了两种成型在翘曲变形、体积收缩、残余应力、温度场分布等方面的本质区别，并基于流变学理论，揭示了微孔发泡注射成型的成型机理。结果表明，微孔发泡注射成型的翘曲变形、残余应力、成型压力和成型时间明显小于传统注射成型的，且微孔发泡注射成型的翘曲变形和残余应力随着开始发泡的熔体预填充体积分数减小而减小，微孔发泡注射成型的熔体温度在浇口附近低于传统注射成型熔体温度，而在远离浇口处则要高。

Comparison of Microcellular Injection Molding Process and Conventional Injection Molding Process

The warpage, residual stress, molding pressure, and temperature field in microcellular injection molding were compared with those in conventional process. Based on rheology theory, the microcellular injection molding mechanism was disclosed. It showed all the warpage, residual stress, molding pressure, and molding time of the microcellular injection molding were obviously smaller than those of conventional molding. The warpage and residual stress decreased with decreasing initial filling volume fraction of the foaming melt. For microcellular injection molding, a lower melt temperature near the gate and a higher melt temperature were needed than those for conventional injection molding.