Silicone Over-Moulding - Silicone bonded to plastics by injection moulding

Silicone over-moulding is a two-step process in which a thermoplastic part is injection moulded and then transferred manually or automatically to a second mould, where a liquid silicone rubber (LSR) is injected.

Used for:
The process is used to add a grip surface to smooth plastic handles, to make integral flexible hinges, and to add soft gaskets for waterproofing on plastic housings.

Details:
Liquid silicone rubber has excellent adhesion to polycarbonate (PC), PBT, Polyamide (PA, Nylon), PET, and PEEK. Silicone offers high elasticity, resilience, and temperature and chemical resistance. The silicone is made from two components that are mixed right before the injection. It is possible to over-mould silicones with different durometers (hardnesses) onto each other.

Idea:
Create a toy that can shoot projectiles with an integrated silicone bungee.

The sample:
The sample is made from glass fibre-reinforced polybutylene terephthalate (PBT). The silicone on the sample can be stretched up to 580 percent before breaking.

All samples come with a laminated information card, which includes contact details for the supplier.