Vacuum Casting
 
SPG-ARRK's vacuum casting service provide high quality, low volume reproductions of SteroLithography prototypes in a variety of polyurethane resins.
 
These may be textured, polished and/or coloured according to customer requirements. Latest additions to the range of finishes include leather-look and walnut finish. This method provides prototypes which resemble the final product not only in shape, but also in appearance and feel, so providing for visual as well as practical appraisal. In turn, these prototypes can prove extremely valuable for early market testing.
 
An increased range of material properties is now available following the introduction on new resins at SPG-ARRK. Examples include fire retardant prototypes, cast in UL94V0 rated polyurathane, and semi-rigid prototypes which emulate the properties of filled polypropylene. The latter is particulary suited for prototypes of auomotive trim and casings for hand tools.
 
The resins can be coloured to a wide range of shades, and ARRK will match pigments for Pantones, RAL and BS classifications or customers swatches on request.
 
 
 Vacuum Casting
 How does it work?
Starting from a model obtained through stereolithography or CNC machining, we duplicate a small series of parts in polyurethanes by vacuum casting in silicone moulds.
 Applications
1-20 parts per silicone tool.
Variable sizes, from small up to 2000x1000x1000 mm.
Insert moulding.
Over-moulding.
 Lead time
Typical lead time is ±14 days (depending on size and complexity).
 Advantages
Parts can be build from a vast array of rigid, elastomeric or transparent polyurethane resins with mechanical and thermal characteristics emulating those of production plastics.
Excellent finishing.
 Disadvantages
Maximum of 20 parts per silicone tool.
Life time of a silicone tools restricted till 3 months.
Polyurethane resin is NOT the true production material.
 
 
 
 
 
 
 
 
 
 
 
 Materials
 ABS simulant
 PA GF simulant
 PC simulant
 PP simulants
A wide choice of Polypropylene simulants is availabe ranging from flexible to rigid and filled with talcum or glass fibers.
 Elastomers
 Silicones