The Vacuum Casting Process
Vacuum Casting Process
Vacuum Casting process, or Urethane Casting process as it is also known is suitable for the production of a small quantity of injection moulded components with the quality of injection moulded parts without the level of financial investment required for tooling development.
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The Vacuum Casting process refers to the production under vacuum of plastic or rubber components from silicone moulds. Parts produced using the vacuum casting process are dimensionally accurate, precise replicas of the master pattern with profiles and texture faithfully reproduced.
Unsure if the vacuum casting process is right for your current project? View the process comparison table.
Vacuum Casting Process
- The Vacuum Casting process begins with the creation of a master pattern using the Sterelithography process. The SLA model is then finished/painted to meet customer specified surface texture is achieved. Where the customer has supplied an existing component for casting, any part clean up is carried out at this stage.
- The master pattern is then fitted with a casting gate and suspended upon the parting line in a mould casting frame
- Silicone rubber is mixed, de-aerated and poured under vacuum into the mould casting frame, where it will flow around the master pattern, to create a silicon mould.
- The mould is then cured within a heating chamber, and once set the mould is removed and cut along the parting line. The master pattern is removed before a casting funnel is placed and the mould sealed closed.
- Customer specified casting resin is then measured and any colour pigment mixed, where specific colour requirements have been outlined. The mould is returned to the casting chamber and the resin is pour into the mould under vacuum to avoid any air pockets or voids.
- When the resin has been cast, the mould is then placed in heating chamber to cure. Once cured the casting is removed from the mould, and any subsequent castings are produced (each mould can be reused with the number of castings greatly dependent on individual part complexity and casting resin selected).
- At this stage the gate and risers are removed from the casting and any additional finishing is carried out.
“We had been using CNC to produce highly accurate models. But Rapid Prototyping produced parts 4 times faster at half the cost”