In the injection processing plant, there are many new techniques for injection molding, and the cause of the weld marks in the injection processing. The weld marks of the plastic products are produced by the failure to complete the fusion of the melt resin from different directions at the bonding process. The two resin flow at the fusion point does not mix with each other during the gelatinization process; therefore, the lower the temperature, the more obvious the fusion mark is, and the strength will also decrease. The higher the temperature, the stronger the adhesion. The bonding state at the fusion point also depends on the pressure exerted on it. The lower the holding pressure, the worse the fusion and the lower the strength. Fusion is the confluent point of the resin, and it may also be the end of the flow. In the weld mark of the plastic products, the appearance and strength of the fusion will be deteriorated if a vent is not set well at this position.

Improvement measures:

L) increasing resin temperature, increasing mold temperature, increasing injection pressure and speed.

2) pay attention to the exhaust of the parting surface and increase the insert and thimble in the production of weld marks.

3) choose a reasonable glue position and make the best mold flow analysis before the plastic products are opened.

4) increase the process of overflow material, and then cut off after molding.

5) as far as possible, coarse and shorten the runner system to improve walking glue.

6) the rough surface can be selected as far as possible. This will also help improve the weld line.

Technology is developing and technology is improving. Here is not a list of the better technologies.