The characteristics of plastic part mold manufacturers are determined by the characteristics of the raw materials. There are two main points: one is the filling flow characteristics of the plastic melt during injection, and the other is the shrinkage position of the plastic in the mold cavity when it is cooled and solidified. The point determines the particularity of the injection mold and the difficulty of injection mold design.
Since the plastic melt is a viscoelastic body, the viscosity of the melt changes with the shear stress and the shear rate when the melt flows. During the flow process, the macromolecules are oriented along the flow direction. After the cavity is filled, the melt is partially compressed, and the process is cooled and solidified. The shrinkage of plastics is very complicated. The shrinkage rates of plastics in various parts and directions in the mold cavity are different. The shrinkage rates of different types and grades of plastics are very different. When the resin or plastic of the same grade is processed, due to the different formulations, its filling flow Sex and shrinkage are also different.
Based on the above characteristics, plastic part mold manufacturers must fully understand the characteristics of the processed plastic raw materials when designing, so that the designed injection mold can be used rationally, and the characteristics of the plastic can be effectively used in the design process. Therefore, the issues that need to be considered in the injection mold design process are as follows.
1. In-depth analysis of the structure of plastic parts and their technical requirements. The structure of the plastic part determines the complexity of the injection mold structure. The technical requirements of the plastic part (dimensional accuracy, surface roughness, etc.) determine the difficulty of the injection mold manufacturing and molding process, so there is no special requirement for plastic injection molding. , Unreasonable structural shapes, etc., plastic part mold manufacturers should propose improved design solutions for injection molded parts, otherwise, it will increase the difficulty of injection mold design and manufacturing and injection molding process;
2. Familiar with the technical specifications of injection molding machines. The technical specifications of the injection molding machine restrict the size of the injection mold and the range of injection products that can be molded;
3. Plastic part mould manufacturers should understand the processing performance and process performance of plastics. Including the flow position of the plastic melt, the larger the flow distance ratio that the melt can achieve: the injection mold manufacturer analyzes the flow resistance of the runner and the cavity, the original air in the mold cavity is discharged, and the plastic is in the injection mold Possible crystallization, orientation and internal stress caused by it, plastic cooling shrinkage and compensation problems, plastic's requirements for injection mold temperature, etc.