About vacuum casting
Besides additive techniques, Materialise offers another type of RP: manufacture of components and small series in silicone moulds. Stereolithography masters are used to build these moulds. Vacuum casting lead times are a bit longer than with 3D printing technology but the result is astounding. Products made in silicone moulds have a quality comparable to the final product, which makes them especially suitable for fit and function testing and marketing purposes.
The method uses cast silicone moulds, made as follows: a master model (that typically originates from stereolithography or selective laser sintering) is carefully prepared, to ensure a high quality finish to the surface and the definition of the parting planes. Silicone is cast around the master, partially under vacuum in order to avoid air bubbles being trapped in between master and silicone. After curing, the mould is cut according to the parting planes and the master is removed, leaving a cavity to make copies. The flexibility of the silicone allows limited undercuts, which might avoid slides or additional parting planes.
Two-component polyurethanes are typically used as copying material. This allows fast production of high quality parts. Vacuum casting is a copying technique typically used for the production of small series (10 to 20) of functional plastic prototypes.
In the summer of 2004, Materialise opened a new plant in Velke Brezno in the Czech Republic. The new plant gives us the capability to produce over 45000 high quality vacuum cast parts per year. The new facility makes Materialise the biggest single supplier of vacuum castings in Europe. This expansion into Central Europe gives us the infrastructure to meet the ever-increasing demands of our customers without compromising our high quality standards and reducing our current lead times.