The temperature difference between the mold cavities, attention must be paid to the design of the temperature control to the cooling circuit.

The shrinkage rate of plastic refers to the percentage difference between the size of the plastic part at the molding temperature and the size after being taken out of the mold and cooled to room temperature. It reflects the degree of reduction in size of the plastic part after being taken out of the mold and Molded Automotive Parts cooled. Any plastic products have certain size requirements. Plastic products with matching requirements during use or installation have higher dimensional accuracy requirements.

The difference between the plastic shrinkage rate estimated by the design mold and the actual shrinkage rate and the fluctuation value of the shrinkage rate during the production of the product will affect the dimensional accuracy of the plastic product. Secondly, the shrinkage rate of plastic has a great relationship with the shape of the plastic part, the complexity of the internal structure, whether there are inserts, etc.

In addition, the mold cavity is constantly worn out during use, which makes the size of the products produced by the same mold different when it is new and when it is old. Variations in the installation dimensions and fitting clearances of mold forming parts will affect the tolerances of plastic parts.

For this reason, it is recommended that relevant export companies: If it is the shrinkage problem of extrusion or injection molding products, the corresponding margin should be increased from the mold; if the shrinkage of the raw material is large, glass fiber modification can be used to reduce the raw material's own The problem of large shrinkage rate; if the uneven shrinkage of the product affects the appearance, it should be considered in the thickness distribution structure of the product. In the mold design, temperature control measures must be taken to heat or cool the mold, and in order to minimize the temperature difference between the mold cavities, attention must be paid to the design of the temperature control to the cooling circuit.

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