In the manufacturing process of plastic injection mold, there is always the problem of determining the parting surface. It is a very complex problem, restricted by many factors, and it is often missing one from the other. So when choosing parting surface, we should grasp the main contradiction and give up the secondary factors. Different designers sometimes have different understanding of the main factors, which is related to their own work experience. Some parts have a simple, clear and unique selection of parting surface; some parts have many options. Based on my work experience, the following principles can be adopted:

 

 

 

a) Ensure that plastic products can be demoulded

 

 

 

This is the first principle, because we set the parting surface to be able to smoothly remove the product from the cavity. According to this principle, the parting surface should preferably be on the largest contour line of plastic products, preferably on a plane which is perpendicular to the opening direction. The overall profile of the parting should be reduced, and there should be no concave convex shape that affects the stripping, so as to avoid affecting the stripping.