The choice of material for injection moulds directly determines the quality of the mould, so what are the basic requirements in the selection of materials?
1) Good mechanical processing performance
The production of injection mold parts, most of which are completed by mechanical processing. Good mechanical processing performance is necessary to achieve high-speed processing. Can extend the life of the processing tool, improve cutting performance, reduce surface roughness, in order to obtain high-precision mold parts.
2) Adequate surface hardness and wear resistance
The surface roughness and dimensional accuracy of plastic products and the service life of injection mold are directly related to the roughness， hardness and wear resistance of the surface of the injection mold. Therefore, it is required that the molding surface of the injection mold has sufficient hardness, and its quenching hardness should be not less than 55 HRC, in order to obtain high wear resistance and prolong the service life of the mold.
3) Sufficient strength and toughness
Because the injection mold is repeatedly subjected to clamping force and injection pressure of the mold cavity in the molding process, especially for large and medium-sized and complex-shaped injection molds, the mold parts material must have high strength and good toughness to meet the requirements of use.
4) Have good polishing performance
In order to obtain high glossy surface of plastic products, the surface roughness of molded parts is required to be small, thus requiring the surface of molded parts to be polished to reduce its surface roughness. To ensure polishability, the material selected must not have defects such as porosity rough impurities.
5) Have good heat treatment process
Mold materials often rely on heat treatment to achieve the necessary hardness, which requires good hardenability of the material. Plastic injection mold parts are often more complex shape, quenching for processing is more difficult, or even simply can not be processed, so mold parts should try to choose heat treatment deformation of small materials, in order to reduce the amount of processing after heat treatment.
6) Good corrosion resistance
Some plastics and their additives in the molding will produce corrosive gases, so the choice of injection mold materials should have a certain degree of corrosion resistance. In addition, nickel, chromium and other methods can be used to improve the corrosion resistance of the mold cavity surface.
7) Good surface processing performance
Plastic products require beautiful appearance.Pattern decoration requires chemical etching pattern on the surface of the mold cavity, so the mold material is required to etch pattern easily, pattern clear, wear-resistant.
Post time: Aug-10-2022
