1、 Mold opening direction and parting line

When designing each injection product, the first step is to determine its mold opening direction and parting line. In the design, the use of a core pulling slider mechanism should be minimized to simplify the mold structure, and attention should be paid to eliminating the influence of parting lines on the appearance.

After determining the mold opening direction, the reinforcement ribs, buckles, and other structures of the product should be designed to be consistent with the mold opening direction as much as possible, avoiding core pulling, reducing splicing gaps, and extending the service life of the mold. In addition, appropriate parting lines should also be selected to avoid reverse stitching in the direction of mold opening, thereby improving the appearance and performance of the mold.

2、 Choose the appropriate draft angle when customizing mold opening

1. Choosing the appropriate draft angle when customizing the mold can avoid product embossing. The demolding angle of the smooth surface should be less than 0.5 degrees, the fine grain surface (sand surface) should be greater than 1 degree, and the coarse grain surface should be greater than 1.5 degrees.

2. An appropriate demolding angle can prevent top damage to the product, such as whitening, cracking, deformation, etc.

3. When customizing the mold for deep cavity structure products, the outer surface slope should be as much as possible greater than the inner surface slope to ensure that the mold core does not shift during injection molding, the product wall thickness is uniform, and the material strength at the product opening should be guaranteed.

3、 Product wall thickness

Each type of plastic has a certain wall thickness range, generally ranging from 0.5 to 4mm. When the wall thickness exceeds 4mm, it will prolong the cooling time and cause problems such as shrinkage printing. Therefore, it is necessary to consider changing the product structure for improvement. Uneven wall thickness will lead to surface shrinkage, as well as porosity and weld marks.