气体辅助注射成型充填过程的数值模拟

描述了气体辅助注射成型的工艺过程及熔体充填和气体穿入的数学模型，采用有限元/有限差分/控制体积法计算充填阶段的压力场和温度场，确定熔体前沿和熔体/气体界面两类移动边界，并对典型制件充模过程进行了模拟.

PROCESS AND NUMERICAL SIMULATION IN FILLING STAGE OF GAS-ASSISTED INJECTION MOLDING

The gas-assisted injection molding(GAIM)process, as an in no vative technology, is being increasingly used in the plastics industry. It is d erived from the conventional injection molding process. GAIM provides benefits in material saving and improved processing capabilities, but it is a more comple x manufacturing process than conventional injection molding of plastic because i t involves a greater number of manufacturing stages and process variables. The flow is also made more complex by the combination of low and high viscosity fluids. So CAE(computer-aided engineering)simulation software is expected t o become an important and required tool to assist in parts design, mold design, and process evaluation in the coming age. This paper presents the process of gas-assisted injection molding and a mathema tical model to describe the mold filling and the gas penetration during the gas -assisted injection molding. A hybrid Finite element/finite difference/control volume method is used to calculate the pressure field, to trace the moving boun daries, one for melt front, the other for gas/melt interface. A typ ical part is simulated to demonstrate the applicability of the model.