Abstract:

For the injection-molded plastic part with more than one injection gate and the part with an insert，there would be a welding stage of the melt fronts in the whole filling process. How the melt fronts welded along the thickness direction is one of the key factors affecting the quality of the part，especially the mechanical properties and fiber orientation. In this paper the velocity and pressure of the melt plastic in the welding stage were simulated with the finite element method（FEM）of the T6P3 triangular element（quadratic velocity and linear pressure）.Two examples were used for the comparison of the velocity and pressure of the melt plastic in the thickness direction in the welding stage. One had an even thickness while the other not. For the given examples，the simulation results illustrated that the plastic welding process would be influenced by the thickness uniformity of the region where weld lines existed. The results of this paper could be the input data for other simulation of plastic injection molding，such as mechanical properties and fiber orientation，etc.

摘要：

在多浇口和带嵌件注塑制品的成型过程中必然存在熔体的熔接过程，从而形成熔接线。熔接线沿厚度方向的熔接过程是影响该区域的力学强度以及纤维取向等制品性能的重要因素。本文采用有限元法针对注塑制品的典型截面建立数学模型，采用T6P3单元（速度二次插值，压力线性插值），数值模拟了注塑制品熔接线的截面熔接过程。通过等厚度截面和非等厚度截面两个算例，给出了两股熔体熔接过程中的截面速度场和压力场分布。讨论了熔接线区域的壁厚均匀程度对熔接过程的影响。该计算结果可以为制品力学性能以及纤维取向等数值模拟提供数据支持。