工艺参数与气肋设计对气辅注射成型的影响

以实例研究了欠料注射量、延迟时间、气体注射压力和熔体温度等气辅注塑工艺参数，以及气肋是否设计倒角对气辅注射成型的影响，包括对气腔长度、制件弯曲强度和翘曲度、手指效应的影响。结果表明，欠料注射量和延迟时间是影响气腔长度、手指效应和弯曲强度的主要工艺参数。气肋的几何形状对气辅注射成型也有重要的影响，设计倒角不仅提高了制件弯曲强度，还减弱了手指效应。

INFLUENCE OF PROCESSING PARAMETERS AND RIB DESIGN ON THE GAS-ASSISTED INJECTION MOLDING

Some of the processing parameters about gas-assisted injection molding is studied. They include shot size, gas delay time, gas pressure, and melt temperature. The responses evaluated include gas penetration length, bending strength, warpage and fingering. The result showed that shot size and gas delay time were the primary factors influencing gas penetration length, bending strength and fingering. Increasing shot size results in enhancing bending and weakening fingering. At the same time it reduces gas penetration length. Delay time is one of the important factors that GAIM is sensitive to. However gas pressure and melt temperature have little effects on them. The influence of rib geometry is also looked into. It is proved that the part with a fillet will enhance bending strength, in this regard, raising the strength/weight rate. The fillet added can also weaken fingering, and shorten gas penetration length. Comparison of parts with various gas channel geometries indicated that the addition of a fillet improved the limits of the molding conditions.