The vacuum casting process
Vacuum casting components can be used in applications from automotive under-bonnet, high quality mouldings for trim and consumer products, through to high performance structural parts in vacuum cast glass filled nylon. All possible without the need for hard steel tooling.
The vacuum casting process involves encapsulating a master model in liquid silicon rubber; a vacuum is then applied to the mould. The mould is then cured in an oven at around 70ºC.
Once cured, the mould can be cut open, at which point the master mould is removed leaving a mould cavity perfectly replicating the master model. Master models are typically made from Stereolithgraphy models, which are painted and textured to give the desired finishes.
The quality of the master model dictates part quality, and complexity can be accommodated through multi-segmented moulds. The polyurethane resin materials are mixed and poured into the silicon mould under a vacuum to avoid voids and bubbles before being cured in an oven. For higher production rates, multiple parts can be moulded simultaneously in one silicon rubber mould.