The design of injection molded parts generally requires the design of the number and arrangement of mold cavities. The cavity of the mold cannot simply apply the dimensional tolerance of the mechanical parts. The dimensional accuracy of the plastic parts will be affected by many factors such as the structure of the plastic parts, the raw materials of the plastic parts and the shrinkage rate of the plastic parts during production. Therefore, the positioning of the mold cavity It is necessary to follow certain principles to meet the requirements of mold manufacturing.

The principle requirements for the positioning of the mold cavity are as follows:

1. The principle of the shortest flow channel: to prevent the pouring material of the pouring system, it can also save the manufacturing cost of steel and molds, and improve the qualification rate of products in the injection molding process.

3. The principle of pressure balance: make the combined force of the mold subjected to the expansion force close to the center of the mold during injection, and be on the same straight line as the clamping force of the injection molding machine, to avoid the uneven molecular orientation caused by unbalanced flow, resulting in inconsistent shrinkage.

2. The principle of temperature balance: make the temperature of the mold cavity roughly equal, and ensure that the shrinkage of the plastic parts of each cavity is equal.

4. Feeding balance principle: For a mold with multiple cavities, the same plastic part should be fed from the same position to ensure the interchangeability of the plastic parts; the size and length of the runner and gate should be compatible with the size of the plastic parts Try to ensure that all cavities are fed at the same time, and at the same time be filled to ensure that each cavity is fed uniformly.

Reasonably design and manufacture the cavity of the molded parts of the injection mold to ensure the molding quality of the plastic parts and improve the production efficiency of the mold.

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