聚丙烯微阵列结构制品熔体充填行为

根据微阵列结构制品熔体的充填特性,设计直径为500 μm的微圆柱阵列结构制品模型,并加工注射成型模具,对微圆柱结构制品熔体的充填规律进行实验和模拟研究。结果表明:微结构制品熔体的充填过程和流动前沿形态的实验结果与模拟分析虽然在趋势上比较一致,但在微圆柱成型过程中,流动前沿的形成过程和充填高度的模拟变化规律与实验结果有一定偏差;实验还发现,前期充填阶段对微圆柱成型的贡献较小,微圆柱内流动前沿的形成受到熔体流动速度、微圆柱模壁、熔体流动惯性影响较大,熔体流经微圆柱结构时产生向上的流动涡流,流动前沿形状呈偏心椭球冠状并逐渐发展成球冠状。

Filling behavior of iPP micro-array structure product by micro injection molding

Filling behavior of micro-array structure product of iPP was investigated by numerical analysis and injection molding experiments.An injection mold was designed to produce products with micro-cylinder structure 500 μm in diameter.The filling process of flow front of micro-cylinders of numerical simulation and injection molding experiment was relatively consistent in the general trend.However,formation of flow front and varying patterns of the height of micro-cylinder in the filling process in the numerical simulation deviated from the experiment.Injection molding experiment showed that micro-cylinder mold wall,melt flow rate,and melt flow inertia played an important role in the formation of flow front.Early filling contributed little to the micro-cylinder molding.Turbulence appeared on the melt flow directly below the micro-cylinder.The flow front was like the shape of acentric ellipsoid crown and gradually developed into the shape of spherical crown.