Vacuum casting machine	Part with silicon mold

Applications

Frequently, one prototype alone is not enough to meet the needs of the whole design team (designer, developer, toolmaker, marketing specialist, etc.). Starting from a single prototype, typically a Stereolithography master, this method allows one to build small series from the master, economically mould. The available materials are thermoplastic or elastomer-like duroplastic materials with customised properties.

Infrastructure

Several vacuum casting installations from MCP HEK, maximal mould size (in house) approximately 580 x 500 x 450 mm³

Materials (selection)

A very broad range of materials are available to us. Please find below a coarse classification:

Polyurethanes: mainly thermoplastic properties
Polyurea: mainly elastomer-like properties
Wax
Silicon

The process

The finalised Stereolithography master together with a special overflow system is cast into a silicon mould. After hardening, the mould is split and the master is removed. The interior sides of the mould are coated with a silicon spray which prevents the prototypes from adhering to the mold. The mould is closed and placed in the lower chamer of the casting machine. Simultaneously, in the upper chamber, the two components of the resin are evacuated. Those two components are now blended and cast into the mould. The part is finished manually and may be sandblasted or treated with an antistatic spray.