板厚对夹芯注射成型芯层物料填充能力的影响

Effect of Plate Thickness on Filling Capacity of Core Material for Sandwich Injection Molding

基于Cross-WLF黏度控制方程,构建了3种典型夹芯注射成型芯/壳层物料组合,并研究了不同物料组合时板厚对芯层物料填充能力的影响。研究表明,调整板厚将使芯、壳层熔体流动状态和黏度发生变化,但上述变化因物料组合不同而呈现显著的差异性:当芯层熔体流动指数相对壳层熔体更大时,随板厚增大,芯/壳层熔体黏度比(R)减小,芯层物料填充能力降低;当芯层熔体流动指数相对壳层熔体更小时,随板厚增大,R增大,芯层物料填充能力升高;当芯、壳层熔体流动指数相当时,上述现象均不明显。

Based on Cross-WLF viscosity control equation,three typical core/skin material combinations for sandwich injection moulding were constructed,and the effect of plate thickness on the filling capacity of core material under different material combinations were studied. The results show that the flow state and viscosity of core and shell melt would be changed by the adjustment of plate thickness,however the above changes could show significant differences due to different material combinations. When the flow index of core melt is larger than the skin melt,with the increase of plate thickness,the viscosity ratio of core/shell melt( R) could decrease,and the filling capacity of core material would decrease. When the flow index of core melt is smaller than the skin melt,with the increase of plate thickness,R could increase,and the filling capacity of core material would increase. When the flow index of core and skin melt is equal,the above phenomena are not obvious.