Which key points should be paid attention to in the design of Injection mold construction?

Which key points should be paid attention to in the design of Injection mold construction?

1. Product wall thickness

(1) All types of plastics have a certain wall thickness range, generally ranging from 0.5 to 4mm. When the wall thickness exceeds 4mm, it will cause excessive cooling time and problems such as shrinkage printing. Therefore, it is necessary to consider changing the product structure.

(2) Uneven wall thickness can cause surface shrinkage.

(3) Uneven wall thickness can cause pores and weld marks.

2. Mold opening direction and parting line

At the beginning of the design of each injection molding product, it is necessary to first determine its mold opening direction and parting line to ensure that the core pulling slider mechanism is minimized and the impact of parting line on the appearance is eliminated as much as possible.

(1) After the mold opening direction is determined, the reinforcement ribs, buckles, protrusions, and other structures of the product should be designed as consistent as possible with the mold opening direction to avoid core pulling, reduce seam lines, and extend the mold life.

(2) After determining the mold opening direction, an appropriate parting line can be selected to avoid undercutting in the mold opening direction, in order to improve appearance and performance.

3. Demolding slope

(1) An appropriate demolding angle can prevent product galling (embossing). The demolding slope of a smooth surface should be ≥ 0.5 degrees, with fine grain (sand surface) surfaces greater than 1 degree, and coarse grain surfaces greater than 1.5 degrees.

(2) Appropriate demolding angle can avoid product top damage, such as top whitening, top deformation, and top breakage.

(3) When designing deep cavity structure products, the outer surface slope should be greater than the inner surface slope as much as possible to ensure that the mold core is not misaligned during injection molding, obtain uniform product wall thickness, and ensure the material strength of the product opening.

4. Reinforcing rib

(1) The reasonable application of reinforcing ribs can increase product rigidity and reduce deformation.

(2) The thickness of the reinforcing rib must be ≤ (0.5-0.7) T, which is the wall thickness of the product, otherwise it will cause surface shrinkage.

(3) The single slope of the reinforcing rib (Shanghai Mold Design Training School) should be greater than 1.5 ° to avoid top injury.