Author: MULAN -Plastic Molding Manufacturer
What conditions should we pay attention to when purchasing plastic molds? Let's take a look with Mulan Precision, an injection mold processing manufacturer! 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 cavity surface to dissolve, peel off, deteriorate the surface condition, and deteriorate the quality of the plastic part. Therefore, mold injection molding manufacturers recommend that you use corrosion-resistant steel, or chrome-plated or cymbal-nickel-plated on the surface of the cavity.
2. Good wear resistance The gloss and precision of the surface of plastic parts are directly related to the wear resistance of the plastic cavity surface. Especially when glass fibers, inorganic fillers, and some pigments are added to some plastics, they flow together with the plastic melt in the runners and cavities at high speed, causing great friction on the cavity surface. If the materials are not wear-resistant, they will wear out quickly, compromising the quality of the plastic part.
3. Good dimensional stability When plastic is molded, the temperature of the plastic cavity should be above 300°C. For this reason, injection mold manufacturers recommend that you choose tool steel (heat-treated steel) that has been properly tempered. Otherwise, the material microstructure will change, resulting in dimensional changes in the plastic mold.
4. Most of the mold parts that are easy to process are made of metal materials, and some structural shapes are very complicated. In order to shorten the production cycle and improve efficiency, the mold material is required to be easily processed into the shape and precision required by the drawings. 5. Plastic parts with good polishing properties usually require good gloss and surface state, so the roughness of the cavity surface is required to be very small.
In this way, the surface of the cavity must be treated, such as polishing, grinding, etc. Therefore, the selected steel should not contain rough impurities and pores. 6. In order to improve hardness and wear resistance, plastic molds are usually subjected to heat treatment, but this treatment should cause little change in size.
Therefore, machinable pre-hardened steels are used.