Low-Pressure Overmolding

Low-pressure overmolding involves molding a component directly into a polyurethane part under relatively low temperatures and pressures. Depending on the desired appearance and application of the final product, the molded-in component can be fully or partially enclosed by the molded part. This method obviates the necessity for primers or adhesives for bonding, as the component chemically adheres to the polyurethane part, resulting in an exceptionally robust bond.

This process owes its feasibility to reaction injection molding. The blend of polyol and isocyanate used in reaction injection molding generates a low-viscosity substance akin to motor oil. This motor oil-like material can be easily injected into a tool without requiring high temperatures or pressures to ensure it fills every nook and cranny.