气体辅助注射成型过程动力学分析

基于气体穿透机理和Hele-Shaw流动模型,对管状模腔中气体冲破熔体前沿形成中空制品气辅成型过程进行了研究,推导出反映充模流动压力梯度比、非牛顿幂率指数等影响因素与计算表层熔体厚度比之间关系的数学公式,建立了熔体前沿和气体前沿速度与位移演化关系的数学模型,分别得出了牛顿流体和非牛顿流体选取不同影响参数时熔体前沿和气体前沿速度、位移的演化曲线.模拟结果表明,所建数学模型能较好的反映熔体前沿和气体前沿速度、位移演化关系.在气体冲破熔体前沿以前,气体接近匀加速运动,前沿位移梯度逐渐增加;熔体前沿的速度几乎保持不变,位移随时间接近线性增长.当气体冲破熔体前沿时,熔体和气体前沿的速度和位移均急速上升.

Dynamic Analysis on Gas-Assisted Injection Molding Process

A theoretical study was carried out on the hollow plastic in gas-assisted injection molding(GAIM) process based on Hele-Shaw approximation.The mathematic model,which can describe skin-melt thickness formation,was presented via providing reasonably assumptions.On the base of the above,a mathematic model was provided to describe the displacement and velocity of gas front and melt front on hollow plastic in GAIM process.The implementation and analysis of numerical simulation of displacement and velocity of gas front and melt front at various time are fulfilled of Newtonian and non-Newtonian fluid.The results indicate that the mathematic model can well describes the displacement and velocity of gas front and melt front,and during the whole process except close to the blow-out time,the velocity of the gas front accelerates,while the velocity of melt front remains constant.When the blow-out happens,the velocity and displacement of gas front and melt front increase dramatically.