Method for casting precision castings

摘要

This method relates to an improvement of the hot-wax casting method, which is widely used especially in the jewellery industry. The improvement consists in that (a) as the moulding composition for the production of the negative mould in which, in turn, the wax pattern is cast, use is made of a pourable silicone rubber which can be hardened to give a silicone elastomer and that (b) the silicone-rubber mould halves are pretreated by being dipped in a hot water bath containing a surface-active agent and that (c) the hot spray wax of the pattern is injected into the negative mould using a vacuum. The precision castings cast in accordance with this variant of the method can have increased accuracy in reproducing the shape of the mould and require less intensive finishing. As the positive moulding composition, it is also possible to use plastics and low-melting metal alloys instead of wax.