Ejector mark is the phenomenon of stress whitening and stress elevation where appears on the opposite side of the nozzle facing the product, or where the ejector rod is located on the ejecting side of the tool.

Why will it cause the ejector marks?
The physical reason is when the demoulding force is too high or the surface of the ejector rod is relatively small, the surface pressure will be very high, and the deformation will eventually cause the ejector marks.

How to improve this defect?

If it is related to processing parameters, it can be improved through:
1. Lower pressure retention
2. Shorten the pressure holding time
3. Advance switching of pressure holding time
4. Extending cooling time

If it is related to the design, it can be improved throght:
1. Selection of demoulding draft angle according to specification
2. Polishing the mold in the direction of demoulding
3. Equip air valve