Control of shrinkage rate of injection molded parts

Injection molding process:

1. The mold temperature should not be too high. 2. The barrel temperature should not be too high. . ​ plastic injection moulding     ，3. The injection pressure can be increased appropriately. 4. Properly increase the injection speed. 5. The holding time should be set longer. 6. Properly increase the cooling time. 7. Control the cooling speed of the mold.


Material:

Select materials with uniform particles, so that the particles are heated evenly, the temperature is uniform everywhere, and the cooling rate is uniform. It is necessary to select the appropriate molecular weight and melt index, so that the process conditions are easy to control, the filling flow is stable, and the shrinkage rate is reduced.


On the mold side:

According to the mold shrinkage rate, the mold cavity size tolerance should be reasonably designed, and the mold material with the small expansion coefficient should be selected.

1. The gate cross-sectional area is appropriately increased to help reduce shrinkage.

2. Shorten the inner flow channel and reduce the flow length ratio, which is beneficial to feeding.



like：

​Factors of discoloration of injection molded products  

​Technical properties of thermosetting plastics  

​Reasons for excessive burrs in injection molded products   




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