Vacuum casting

Vacuum casting

An advantageous and fast technique

Vacuum casting is an advantageous and fast technique for producing small series or prototypes where the right material properties are important for functional testing.

A soft silicone tool is made from a 3D-printed SLA master. In the cavity that the SLA master creates is the silicone, 20-25 components can be cast with the desired material properties, color and finish.

The materials used are polyurethane-based with different properties and several different thermoplastics can be simulated, including glass fiber reinforced. The picture shows a customer project on a 2k-molded electronics enclosure with smooth surfaces, the materials simulate PP and a soft TPE, respectively. About twenty components were cast to test so that

The sealing principle worked as intended and the microswitches under the TPE buttons gave the correct response.

When you want to perform functional testing of your prototype

In development projects, there is often a need to undertake functional testing of the final design early on, using materials that simulate the plastic of the final construction. By producing casting moulds from silicon, parts can be cast in polyurethane (PUR) with the required properties.

Small series production

Vacuum casting is advantageous where small series production of plastic parts is required. The time required to produce a die is normally very short. The die is usually cast in silicon from a 3D printer master. The method does not require much post-processing, and the parts are like ordinary thermoplastics in their properties, e.g. hard, soft, rigid, flexible, heat-resistant and transparent.

To bear in mind

  • Parts cast in PUR that simulate various thermoplastics, from rubber grades in Shore 30 to 95A to glass-reinforced rigid materials.
  • V0 fire-rated material is also available.
  • The parts can be dyed the required colour; specify e.g. NCS or RAL colours.
  • Glass fibre can be added for greater torsional stiffness.
  • Around 20 to 25 parts can be cast in each mould cavity. More mould cavities can be created for larger quantities.
  • There is no problem adding metal parts or electronics to the cast.
  • Allowance should be made for release angles.
  • If you want stronger threads, we can include thread inserts in the cast or fit them afterwards.