Considerations in the Design of Precision

The market prospect for precision molds is promising. Below are key considerations for the design of precision molds:

1. The shape and dimensional accuracy of the molded product, resin flow direction, transfer of injection pressure, and solidification status of the filled resin. As a mold designer, you must fully understand product requirements, which is the starting point of precision mold design. A thorough grasp of product specifications is essential.

2. Properties of the molded product. Systematically list the characteristics of the molded part, especially material properties and product geometry, which serve as the basis for detailed mold design.

3. Mold structure. The structural scheme of precision molds differs from that of ordinary plastic molds. Multiple feasible structural options may be available for conventional plastic molds, while certain structures may exert adverse effects on precision molds. Therefore, structural requirements for some precision molds are stringent, mainly to avoid impacts of mold movements on finished products.

4. Mold rigidity and strength. Based on practical experience, mold rigidity is critical. It is common to see molds with thin mold bases and cavity inserts. Such molds may be functional for production, yet some product defects are closely related to insufficient mold strength and can be hard to identify.

5. Gates and runners are vital factors for product quality. Precision molds have specific requirements for gating methods. Optimizing gate marks can bring unexpected improvements to finished products.

6. Mold temperature control circuit. The mold temperature must be kept uniform. Temperature gradients matching the resin flow direction should be set, and targeted solutions shall be arranged for sections with varying wall thickness. The mold surface temperature at the product area must be consistent the moment the molded part is ejected, which requires a well-designed cooling system.

7. Precision molds have high tolerance requirements, so the machining method adopted for mold fabrication matters greatly. The product cavity is divided according to the molded part shape, and wire electrical discharge machining (WEDM) is widely used. Machining processes should be taken into account during the design phase.

8. The mold structure shall be reasonably designed to facilitate additional modifications. For example, if a certain position performs unsatisfactorily after mold trial, remedial solutions need to be implemented.