Six requirements for injection mold selection
Injection mold is a tool for the production of plastic products. In order to allow parts to be formed smoothly, we need to pay attention to some problems when choosing injection mold.
1. Many resins and additives with high corrosion resistance have corrosion effects on the surface of the mold cavity. This corrosion causes metal corrosion and peeling on the surface of the mold cavity.Therefore, corrosion resistant steel should be used as far as possible, or the surface of the cavity should be treated with chromium plating and nickel cymbals.
2, good abrasion resistance, gloss on the surface of the injection molded parts and precision and injection mold cavity surface wear resistance has a direct relationship, especially some plastic adding glass fiber, inorganic filler and some paint, they and the plastic melt in the runner and cavity with high flow velocity, friction on the surface of cavity is very big, if material not wear-resisting, will soon wear and damage to parts quality.
3, good dimensional stability during injection molding, injection mold cavity temperature to reach above 300 ℃.For this purpose, use tool steel (heat treatment steel) that has been properly tempered as far as possible.Otherwise, the material microstructure will be changed, resulting in the injection mold size changes.
4. In order to shorten production cycle and improve efficiency, mold materials are required to be easily processed into shapes and precision required in drawings.
5. Good polishing performance of injection molded parts usually requires good glossiness and surface condition, so the roughness of the cavity surface is required to be very small. In this way, the cavity surface must be processed, such as polished and ground.Therefore, the selected steel should not contain rough impurities and pores.
6.In order to improve the hardness and wear resistance, generally the injection mold should be heat treated. However, this treatment should make the size change very small.Therefore, try to use pre-hardened steel that can be machined.