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.