The shrinkage rate of the molding material in the injection mold factory has a great influence on the dimensional accuracy of the plastic parts. Generally, the greater the shrinkage rate of the molding material, the more difficult it is to ensure the accuracy. Therefore, the influence of the shrinkage rate of the raw material after molding on the dimensional accuracy of the plastic part must be considered when selecting the molding resin. PTJ has its own understanding of how to balance the two.
Injection molds usually have a larger shrinkage rate of crystalline and semi-crystalline resins than non-crystalline resins, and the range of shrinkage rate changes is also larger. Correspondingly, the shrinkage rate fluctuations of plastic parts after molding are also relatively large. In addition, the particle size of the molding raw materials is not uniform, and the mixing of poorly dried recycled materials and new materials is not uniform. The different properties of each batch of raw materials will also cause fluctuations in the molding size of plastic parts.
Any product injection mold factory should control the incoming materials and have a detailed understanding of the problems that may arise during the use of plastic materials, so as to be able to do better in the production of plastic mold products, and to produce better and smoothly, and to provide quality to customers .