Rapid Injection Moulding, an Overview

Fig. 1: The Injection Moulding Process

Over the last several years, these emails have addressed many details of design for rapid injection moulding, but we've never really looked at the overall process. In its simplest form, the injection moulding process works as follows:

1.       Injection moulding resin in pellet form, is loaded into the hopper.

2.       The pellets flow into the heated barrel, where the material is melted.

3.       A ram-driven screw injects the molten material into the closed mould.

4.       After the material cools and solidifies, the mould opens and the part is ejected.

Fig. 2: Protomold's Demo Mould

Add side-actions and the process gets a little more complicated. If you've already received one of our free demo moulds, you've seen how a two-part mould with a side-action cam works. If you haven't received one yet, go to our web site to order one. Meanwhile, here's a 2D version: