What Are the Requirements for Injection Molding Mold Design?

The characteristics of injection molding mold are determined by the characteristics of the raw materials, mainly in two aspects

The first is the filling and flow characteristics of the plastic melt during the injection process, and the second is the shrinkage position of the plastic during the cooling and solidification process in the mold cavity. These two points determine the special nature of plastic molds and the difficulty of injection molding mold design.

Since plastic melt belongs to a viscoelastic body, the viscosity changes with shear stress and shear rate when the melt flows. During the flow process, the large molecules are oriented along the flow direction. After the mold cavity is filled, the melt is partially compressed, and the shrinkage of the plastic during cooling and solidification is extremely complex.

The shrinkage rate of plastics in different parts and directions of the mold cavity is different, and the shrinkage rate of different types and brands of plastics is also greatly different. When processing the same brand of resin or plastic, due to different formula, their filling flow and shrinkage rate are also different.

Based on the above characteristics, it is necessary to fully understand the characteristics of processed plastic raw materials in the design of injection molding mold, so that the designed injection molding mold can be used reasonably and the plastic characteristics can be effectively utilized in the design process.

The following issues should be considered in the design of injection molding mold

• The structure of plastic parts determines the complexity of the plastic mold structure and the technical requirements of the plastic parts (dimensional accuracy, surface roughness, etc.), thereby determining the difficulty of manufacturing and forming of plastic injection tooling. Therefore, for those special requirements that do not meet the characteristics of plastic injection molding, and unreasonable structural shapes, injection molding parts design schemes should be proposed for improvement, otherwise it will increase the difficulty of injection mold design, manufacturing and injection molding process.

• Familiar with the technical specifications of the injection molding machine. The technical specifications of the injection molding machine limit the size of plastic molds and the range of injection molded products that can be formed.

• Understand the processing and processing characteristics of plastic injection tooling, including the flow position of plastic melt, the maximum flow distance ratio that the melt can reach, the flow resistance analysis of the flow channel and cavity, the discharge of original air in the cavity, the crystallization and orientation that plastic may cause in the plastic injection tooling and its internal stress, the cooling shrinkage and compensation of plastic, and the temperature requirements for plastic injection tooling.

HanKing Mold designs and manufactures plastic injection tooling in China, provides our global customers with large factories, and provides injection molding production services for customers, including secondary processing and assembly. Our global customers come from the United States, Germany and other parts of the world, Switzerland, France, Italy, Austria, Israel, etc. Welcome to inquire.