Vacuum casting is a casting process for elastomers using a vacuum to draw the liquid material into the mold. This process is opted when air entrapment become an issue. Such issue is being seen in intricate details or undercuts, and when the material fiber or wire is reinforced. Vacuum casting is the precision alternative to injection molding, RIA, foam molding, or machining. Especially effective in low volume applications, it provides an economical and fast way of making accurate multiple prototypes.
The process starts by placing a silicone mold in a vacuum chamber. The raw material is mixed, degassed and poured into the mold. The vacuum is then released and the mold can be removed from the chamber. Finally, the casting is cured in an oven and the mold is removed to release the completed casting. The silicone mold can be reused.