How to choose parts for the structural principles of injection plastic parts
First: When designing plastic parts, the molding processability of raw materials, such as flowability and shrinkage, should be considered.
Second: When designing plastic parts, the overall structure of the mold should be considered, so that the mold cavity is easy to manufacture, and the core and the ejection mechanism of the mold are simple.
Third: On the premise of ensuring the use performance, physical and chemical properties, electrical properties, chemical resistance and heat resistance of plastic parts, we strive to have a simple structure, uniform wall thickness, and easy use.
Fourth: When the appearance requirements of plastic parts with injection molding meters are high, the model should be adopted first, and then the drawings should be drawn gradually.
The structural and technological design of plastic parts mainly includes: size, accuracy, surface roughness, shape of plastic parts, wall thickness, slope, stiffeners, support surfaces, fillets, holes, threads, gears, inserts, text, Symbols and marks.
Injection molding mold is a tool for producing plastic products, and it is also a tool that gives plastic products a complete structure and accurate dimensions. High-pressure injection from the injection molding machine into the mold cavity, after cooling and solidification, to obtain a molded product.
Injection molding mold is a tool for producing plastic products, and it is also a tool that gives plastic products a complete structure and precise dimensions. The high-pressure plastic is injected into the mold cavity by an injection molding machine, and after cooling and solidification, a molded product is obtained.
1. Molded parts refer to mold parts that are directly in contact with plastic to form products, such as cavities, cores, sliders, inserts, inclined tops, side draws, etc.
2. The material of the molded parts is directly related to the quality and life of the mold, which determines the appearance and intrinsic quality of the molded plastic product. It must be very careful. Generally, it must be based on the contract and customer requirements, and according to the requirements of the product and mold. And characteristics.
3. The selection principles of molding parts materials are: according to the type of plastic molded, product shape, dimensional accuracy, product appearance quality and use requirements, production batch size, etc., taking into account material cutting, polishing, welding, etching, Deformation, abrasion resistance and other properties, while considering the economy and the manufacturing conditions and processing methods of the mold to choose different types of steel.
4. For molds for forming transparent plastic products, both the cavity and the core of the mold need to have high mirror polishing performance.
5. For molds with high appearance quality requirements, long life, and mass-produced molds, the material selection of the molding parts is as follows :.
a) The cavity needs to be made of ** imported steel with high mirror polishing performance, such as 718 (P20 + Ni), NAK80 (P21), etc., all are pre-hardened, and no further heat treatment is required.
b) The core can be selected from low-grade imported P20 or P20 + Ni steel, such as 618, 738, 2738, 638, 318, etc., all are pre-hardened. For molds with small production batches, domestic plastic mold steel can also be selected. Or S50C, S55C and other imported high-quality carbon steel, injection processing.