Some Ways To Prevent Ejector Pin Marks

The most common culprits of ejector pin mark include:

Over-high injection pressure, over-fast dwell time, overflow mold temperature accompanied by an over-fast or unbalanced cooling speed, which altogether increase the internal stress of products.

Over-small draft, incorrect or insufficient spraying of the mold-release agent or an over-large ejection resistance.

Improper design of the ejector unit and over-fast ejection speeds can result in large ejection stress among the plastic and ejector parts.

To mitigate the presence of ejector pin marks, consider the following approaches:

1.Reduce both the injection pressure and dwell time.

2.Limit the amount of melt injected into the mold.

3.Optimize the design of the feed system to ensure quality mold filling while slowing down the injection rate.

4.Control the mold temperature and extend the cooling time to allow uniform cooling of the entire part in the mold.

5.Increase the draft angle to facilitate easier part ejection from the mold.

6.Choose an ejection mold design that incorporates carefully positioned ejector pins.

7.Ensure the mold cavity surface is as smooth as possible.sign of structure for the products.