Vacuum casting is a process of model making in which liquid urethane resin is drawn into a silicone mold using vacuum pressure.
Vacuum casting allows us to create prototypes with the appearance of production injected molded quality. The vacuum to pressure process fills molds with intricate details and geometry that are too complex for bench casting.
Our casting lab is equipped with over eight vacuum to pressure capable vessels. With our largest tank, we can fill a mold up to five feet long with over 15 pounds of resin allowing us to make large-scale models. With this process, we specialize in making vac-pressure parts that are water-clear and look as good, if not better, than production.
The process starts with a two-piece silicone mold placed into a vacuum chamber. Liquid urethane resin is mixed and degassed before filling the mold. After the liquid is poured into the mold, we immediately fill the pressure vessel with compressed air up to 80 psi. This combination of vacuum to pressure allows even the most complicated of molds to be completely filled with little or no trapped bubbles. By adding heat to the process, we can eliminate the need for post-curing to speed up the path to final prototype. Once set, the mold is removed from the chamber and the part is carefully released from the silicone.