METHOD FOR MANUFACTURE OF VACUUM FILM MOLDS Russian patent published in 1994 - IPC

FIELD: foundry. SUBSTANCE: frames of two adjacent molds have their side walls joined and removed with the sand simultaneously substituting them due to partial collapse of the sand layers next to the side walls to be removed from the two nearby molds. The alternative is to arrange the subsequent molds so that they have a gap between them which is later filler up with sand. Opposite perforated side walls have a thinned sand layer of increased gas permeability interposed between them through the whole width of the frames. The layer performs the function of vacuum line used to improve conditions of exhausting the gases from the mold. To keep the walls of the mold cavities from deforming the sand layer to be thinned can have the thickness approximating 30 - 70% minimum cavity spacing. This is due to the proper thickness characteristic to the detachable side walls of the frames. EFFECT: control of cooling the castings in a single sand flow with keeping their quality on a stable level, improved durability of molds. 3 cl, 5 dwg