Technology: Selective Laser Sintering Windform® PS is a new polystyrene based material, developed specifically to produce complex investment casting patterns. The sintered patterns are ideal for conventional wax infiltration, and become easy to handle and finish. Windform® PS patterns are designed to work within regular rapid casting procedures, including autoclave and flash firing steps, low-temperature furnaces and vacuum plaster casting methods. Improved properties, compared to other polystyrene materials already available on the market, and that make the difference, are: - Improved surface quality and fine feature preservation - Reduced "curling" effect on the first layers - Very low ash content, therefore well suited for highly reactive alloys, such as Titanium, Aluminium, Magnesium, Steel and Nickel based alloys. Applications: - Complex investment casting patterns - Casting with highly reactive alloys, as well as conventional cast alloys The casting structure is formed from an aggregate of grains or polyhedral crystallites which produce isotropic compensation: it is obvious that isotropy has great advantages, for instance, FEM calculations are very close to the real behaviour of the part. Moreover, Rapid Casting with laser sintered patterns allows complete design freedom (no support structures are needed): thus reducing undercut and tool path problems during CNC machining. It's therefore possible to create the product along its mechanical stress axes, and to obtain a perfect reproduction of all details of the RP pattern, with tolerances and surface finishing of a very high quality (such as fully machined parts).