1, high corrosion resistance Many resins and additives have corrosive effects on the cavity surface, causing the metal on the cavity surface to dissolve and peel off, making the surface condition worse and the quality of plastic parts worse. Therefore, it is best to use corrosion-resistant steel, or chromium plating and samarium-nickel treatment.
2. Good wear resistance The glossiness and accuracy of the surface of injection molded parts are directly related to the wear resistance of the cavity surface of injection mold. Especially, after some plastics are added with glass fiber, inorganic filler and some pigments, they flow rapidly in the runner and cavity together with the plastic melt, which produces great friction on the surface of the cavity. If the material is not wear-resistant, it will soon wear out and damage the quality of plastic parts.
3。 The dimensional stability of injection molding is good, and the cavity temperature of injection mold should reach above 300℃. Therefore, it is best to choose tool steel (heat-treated steel) after proper tempering. Otherwise, the microstructure of the material will be changed, which will lead to the change of the size of the injection mold.
Extended data:
Mold maintenance:
1. Processing enterprises should first equip each pair of molds with a history card to record and count their use, maintenance (lubrication, cleaning and rust prevention) and damage in detail, so as to find out which parts have been damaged and worn, provide information for finding and solving problems, as well as molding process parameters of molds and materials used in products, thus shortening the trial run time of molds and improving production efficiency.
2. The processing enterprise should test the performance of the mold under the normal operation of the injection molding machine and mold, and measure the size of the final molded plastic parts. Through this information, the existing state of the mold can be determined and the damage of the cavity, core, cooling system and parting surface can be found. According to the information provided by the plastic parts, the damage state and maintenance measures of the mold can be judged.
3. It is necessary to focus on tracking and testing several important parts of the mold: ejector and guide parts to ensure the opening and closing movement of the mold and the ejection of plastic parts. If any part of the mold is stuck due to damage, it will lead to production stoppage, so the ejector pin and guide post of the mold should be lubricated regularly (choose the most suitable lubricant).
And regularly check whether the surface of thimble and guide post is deformed and damaged. Once found, replace it in time. After completing a production cycle, professional antirust oil should be coated on the working surface, moving and guiding parts of the mold, especially to protect the elastic strength of the rack and pinion of the mold and the bearing parts of the spring mold to ensure that they are always in the best working condition.
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