What are the requirements for purchasing plastic molds?


1. High corrosion resistance Many resins and additives […]

1. High corrosion resistance Many resins and additives have a corrosive effect on the surface of the cavity. This corrosion causes the metal on the surface of the cavity to be corroded and peeled off, the surface condition is deteriorated, and the quality of the plastic parts is deteriorated. Therefore, use corrosion-resistant steel, or perform chromium plating and cymbal nickel treatment on the surface of the cavity.

2. Good abrasion resistance. The gloss and accuracy of the surface of plastic parts are directly related to the abrasion resistance of the surface of the plastic mold cavity, especially when glass fiber, inorganic fillers and certain pigments are added to some plastics. Together with the plastic melt, it flows quickly in the runner and mold cavity, and has great friction on the surface of the cavity. If the material is not wear-resistant, it will wear out quickly, which will damage the quality of the plastic part.

3. Good dimensional stability. During plastic molding, the temperature of the plastic mold cavity must reach 300°C or more. For this reason, it is best to choose tool steel (heat-treated steel) that has been properly tempered. Otherwise, it will cause changes in the microstructure of the material, resulting in changes in the size of the plastic mold.

4. Easy to process Mold parts are mostly made of metal materials, and some structural shapes are still very complex. In order to shorten the production cycle and improve efficiency, the mold materials are required to be easy to process into the shape and accuracy required by the drawings.

5. Good polishing performance. Plastic plastic parts usually require good gloss and surface condition. Therefore, the roughness of the cavity surface is required to be very small. In this way, the surface of the cavity must be surface processed, such as polishing, grinding, etc. Therefore, the selected steel should not contain rough impurities and pores.

6. Less affected by heat treatment In order to improve the hardness and wear resistance, the plastic mold is generally heat treated, but this treatment should make the size change small. Therefore, pre-hardened steel that can be machined is used.