In the design of injection mold parts, the number and arrangement of mold cavities should be designed first. Mold cavity design can not simply apply the dimensional tolerance of mechanical parts, the dimensional accuracy of plastic parts will be affected by many factors such as the structure of plastic parts, plastic materials and the shrinkage rate of plastic parts in production. Therefore, the arrangement of injection mold cavity should follow certain principles to meet the requirements of mold manufacturing.
The approximate requirements for the arrangement of injection mold cavities are as follows:
- Keep the flow channel as short as possible: prevent solidification of the pouring system, save steel and mold manufacturing costs, and improve the qualification rate of injection molded products.
- Pressure balance: Make the resultant force that the injection mold bears during injection and the locking force of the injection molding machine on the same straight line, avoiding uneven flow that leads to irregular molecular orientation and inconsistent shrinkage rate.
- Temperature balance: Make the temperature in each cavity of the injection mold roughly equal, ensuring that the shrinkage rate of the plastic parts in each cavity is equal.
- Feeding balance: for the the first mock examination with multiple cavities, the same plastic part should be fed from the same location to ensure the interchangeability of plastic parts; The size and length of the runner and sprue should be adapted to the size of the plastic part, and efforts should be made to ensure that each cavity is fed simultaneously and evenly filled.
Reasonably designing injection molds to form parts and ensuring the quality of plastic parts is the basic principle for improving the production efficiency of injection molds.
