Precautions when choosing plastic molds


Plastic mold ( is an abbre […]

Plastic mold ( is an abbreviation for a combined mold used for compression molding, extrusion molding, injection, blow molding and low foam molding. The coordinated changes of the convex and concave molds and the auxiliary molding system can process a series of plastic parts with different shapes and different sizes. In order to meet the needs of molded parts, we need to pay attention to some things when selecting plastic molds, and put forward corresponding requirements.

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 dissolve and fall off, and the appearance condition becomes worse and the quality of plastic parts deteriorates. Therefore, it is best to use corrosion-resistant steel, or chromium plating, cymbal nickel treatment on the cavity surface.

2. Good wear resistance. The gloss and precision of the appearance of plastic parts are directly related to the wear resistance of the plastic mold cavity, especially when glass fiber, inorganic fillers and certain pigments are added to some plastics. It flows at high speed in the runner and mold cavity together with the plastic melt, which has a great impact on the appearance 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. Outstanding dimensional stability. During plastic molding, the temperature of the plastic mold cavity must reach above 300°C. For this reason, it is best to select tool steel (heat-treated steel) that has been properly tempered. Otherwise it will cause changes in the microstructure of the data, and then change the dimensions of the plastic mold.

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

5. Good polishing performance. Plastic parts usually require outstanding gloss and appearance. Therefore, the surface roughness of the cavity is required to be very small. In this way, it is necessary to perform surface processing on the appearance of the cavity, such as polishing and grinding. Therefore, the selected steel should not contain rough impurities and pores.


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