IMPROVEMENT OF MOLDING SURFACE OF CASTING MOLD

PURPOSE:To fill the voids on the surface of a casting mold with pulverous refractory powder and to obtain the mold having high surface density by putting the molded mold into a fluidized bed in which the pulverous refractory powder is fluidized and sucking the mold. CONSTITUTION:A titled method is applicable to a casting mold such as a green sand mold, CO2 sand mold, shell mold or the like consisting of pulverous refractory particles. A cover which seals hermetically and covers a part of the casting mold and a vacuum pump connected to the cover are used as evacuating means. The pulverous refractory powder is required to be smaller than the refractory particles to form the casting mold. The suction force is determined by the size of the voids of the casting mold. The larger suction force is required for the mold having the smaller voids. The mold of which the surface to delineate the product cavity of the mold is made into high density in the above-mentioned way is obtd. The smooth coated surface is obtd. by applying a mold coating material 3 to the mold in the stage of casting.