浇口尺寸对注塑制品性能的影响

Effect of Gate Size on Injection Molded Products′Performance

采用实验方法研究了浇口尺寸及注射压力、注射速度等工艺参数对于熔体填充行为和聚丙烯(PP)注塑件拉伸性能的影响。以3个不同大小的矩形浇口的拉伸样条作为模型,通过动态可视化实验平台对充填过程进行了观察,并对不同条件下熔体充模过程进行比对分析。此外,实验还对试件进行了拉伸测试。结果表明,浇口尺寸、注射速度和熔体温度均显著影响了熔体的充模速度;浇口尺寸的变化对制品弹性模量和拉伸强度会产生不同的影响,适当增大注射速度、注射压力均有利于提高PP注塑件的拉伸性能。

Experiments were carried out to study the effect of gate size and process parameters （eg. injection pressure and rate） on melt filling behavior and tensile properties of PP injection molded parts. Three standard samples with rectangular gate of different size were taken as models, the filling process was observed by dynamic visualization experiment platform. By comparing and analyzing melt filling behavior under different conditions, the conclusion was drawn that the gate size, injection rate and melt temperature significantly affected the filling speed of melt. The tensile test showed that the changes in the size of the gates would produce different influence on modulus and tensile strength of products. A suitable increase in the injection speed and pressure may improve the tensile properties of PP injection molded parts.