Reaction Injection Moulding or RIM involves bringing together two highly reactive liquid monomers into a mixhead and immediately injecting them into a heated mould under low pressure. The monomers react and cure in the mould. This process is used largely for prototyping and low volume production runs where the tooling costs of a conventional hot melt injection moulding system would not be cost effective. ALH Systems have a range of polyurethane and polyurea based resins that are ideal for this application.