Vacuum Casting



Vacuum casting is used in the casting of jewelry or similar small metal parts that have fine detail. The process involves pouring a liquid (usually a polyurethane plastic) into a molded form that is pieced together along a parting line. It consists of three production phases: mold making, part pouring, and the curing process that includes the post cure finishing.

To produce the casting, the liquid mixture is poured into the mold cavity under a vacuum. This vacuum, created by the casting machine’s pump, eliminates air from both the liquid plastic and the mold cavity. Once fully mixed, the mixture is carried from a material chamber to mold chamber through tubing by gravity. Mixing time, mixing speed and temperature of the polyurethane are all factors in the cure time and shrink rate of the cure part.