Plastic parts are vacuum cast by placing a silicone tool in a vacuum chamber with a polyurethane resin.

The two-part resin is mixed and de-gassed before being poured into the silicone cavity. After pouring, the vacuum is released and the tool is removed to a post-curing oven for up to two hours depending on tool size. Following an exothermic reaction of the two-part resin, the cavity is opened and a polyurethane part removed. The silicone cavity is then closed and the process repeated.