Vacuum Casting

Vacuum casting process used for producing accurate silicone rubber moulds for casting of parts (short run prototypes and functional parts) with fine details and very thin walls.

The Vacuum casting process includes the following steps:

  • Step 1 : Production of a pattern using any of the Rapid Prototyping Process like SLA, SLS, FDM etc.
  • Step 2 :The pattern is fit with a casting gate and set up on the parting line and later suspended in a mould casting frame
  • Step 3 :After de-aeration two-part-silicone rubber it is mixed and poured into the mould casting 
                  frame around the pattern.
  • Step 4 :Inside a heating chamber the mould is cured
  • Step 5 :By cutting along the parting line the pattern is removed from the silicone mould.
  • Step 6 :Polyurethane resin (PU) is measured, dye is added for coloured parts and casting funnel is  placed,and then the mould is closed.
  • Step 7 :Vacuum Casting machine which is computer controlled mixes and pour the resin inside the  vacuum chamber. As the process takes in a vacuum, the mould is filled completely without  leaving any air pockets.
  • Step 8 :Then the mould is kept inside the heating chamber for 2 -4 hours to cure the urethane part.
  • Step 9 :After hardening, casting is removed from the silicone rubber mould and finished.