Injection Overmolding Process of Thermoplastic Composites

Looking for a low-cost process to add functionality to its semi-finished composite profiles and tubing and reduce the use of adhesives in its products, Epsilon Composite, together with its injection molding partner Somocap, developed a thermoplastic composite injection overmolding process and Obtained a patent. All images (including those consistent with title): Epsilon Composite

According to a US patent application filed in 2021, the process involves several steps: First, a hollow tubular thermoset composite profile is produced by drawing or pultrusion. The ends of the profiles are then machined to allow the shape of the end fittings to be joined, which provides a rough surface area for the profile to join. Next, the tooling/plug is placed inside the profile of the injection machine, and thermoplastic is injected under specified heat and pressure around the profile and end fittings, bonding them together.

Ultimately, this method could be used as a way to join traditional metal end fittings to pultruded profiles or tubing, or it could replace metal entirely, and thermoplastic composite tips could be added via overmolding.