气体辅助注射成型过程的数值模拟技术

本文描述了气体辅助注射成型过程中熔体充填及气体穿入的数学模型,采用有限元／控制体积法计算充填阶段的压力场,确定两类移动边界,熔体前沿和熔体－气体边界。并对典型制件进行模拟验证了模型的可行性。对不同成型参数如熔体充填百分比及气道直径的影响进行了研究,结果表明熔体充填百分比不够,使气体吹入薄壁,较高的充填比又会阻止气体进入气道;较大直径的气道较小直径的气体不易进入薄壁处。

Numerical Simulation of Gas assisted Injection Molding Process

s This paper presents a mathematical model to describe the mold filling and gas penetration during gas assisted injection molding.A hybride finite element/control volume method was employed to calculate the pressure field,to trace the moving boundaries,one for melt front,the other for gas melt interface.A typical part was simulated to demonstrate the applicabilities of the model.Studies on different molding parameters,such as the effect of melt filling rate and gas channel diameter,were also made.The results showed the gas would penetrate into the skin polymer when melt filling rate was not high enough,but the gas would be prevented to get into gas channel when the melt filling rate was too high;when the gas channel diameter was big,the gas would penetrate into the skin polymer more or less than the case when the diameter was small.