Protomold Plastic Part Ejection Process

Protomold uses pins to eject parts from the mould during production. Designers should be aware of the need to accommodate such pins.

The Protomold Rapid Injection Moulding process uses ejector pins of various sizes to push the plastic part out of the mould after it has solidified. The sizes and arrangement of these pins are selected to minimise the impact on your part design.

Figure 1 is an example of the illustration Protomold provides early in the process of designing the mould so that the location and size of both the gate(s) and ejector pins can be approved.
Figure 1: A typical Protomold-supplied gate and ejector pin layout submitted for customer approval.