How to grasp the shrinkage rate for high-precision plastic part mould?

For high-precision plastic parts, when it is difficult to grasp the shrinkage rate, the following methods are usually used to design the mold:

1. Use a smaller shrinkage rate for the outer diameter of the plastic parts, and a larger shrinkage rate for the inner diameter, so as to leave room for correction after the test.

2. The mold test determines the form, size and molding conditions of the gate system.

3. The plastic parts to be post-processed should be post-processed to determine the dimensional changes (must be measured within 24 hours after demolding).

4. Correct the mold according to the actual shrinkage rate.

5. Retry the mold and appropriately change the processing conditions to slightly change the shrinkage value to meet the requirements of plastic parts.