There are a lot of new injection molding technology in the injection molding factory, and in the injection molding process, the cause of the welding mark, the plastic product welding mark is the injection process from different directions of the molten resin in the joint failed to fully fusion. The two streams of resin do not mix with each other in the process of glue shooting. Therefore, the lower the temperature, the more obvious the fusion mark, and the strength will be reduced. On the contrary, the higher the temperature, the stronger the adhesive force will be. The bonding condition at the fusion point also depends on the pressure applied there. The lower the holding pressure, the worse the fusion and the lower the strength. Fusion is the resin junction point, but also may be the flow end, plastic products in the weld line, if not in this position to set a good vent to vent gas, will make the appearance of fusion and strength deterioration.
Improvement measures:
L) increase resin temperature, mold temperature, injection pressure and speed; Turn up the heat
2) pay attention to the exhaust of the parting surface. It is also beneficial to add inserts and thimbles at the place where the weld mark is generated.
3) choose a reasonable position of the glue, plastic products before mold flow analysis is best;
4) add process overflow and discharge cold material, cut off and remove after molding.
5) shorten and thicken the runner system as far as possible to improve the rubber running;
6) the rough surface can be selected as far as possible, which is also conducive to improving the weld mark.
|
