Abstract: A method for avoiding cracking of the molded body during the decompression step in an isostatic pressing method of molding. The powders to be molded are housed in a shaping rubber mold, are molded under pressure, and the improvement is characterized by supplying forcibly gas between the outer peripheral surface of a molded body or a shaping thin rubber bag where the molded body is housed and the inner peripheral surface of the shaping rubber mold, the gas having a pressure higher than the isostatic pressure applied to the shaping rubber mold at the time when the shaping rubber mold begins to restore to its original state during the decompression step of the method. An apparatus for the said compression molding which is equipped with a specially designed pressure gas inletting device.

Abstract: A method for avoiding cracking of the molded body during the decompression step in an isostatic pressing method of molding. The powders to be molded are housed in a shaping rubber mold, are molded under pressure, and the improvement is characterized by supplying forcibly gas between the outer peripheral surface of a molded body or a shaping thin rubber bag where the molded body is housed and the inner peripheral surface of the shaping rubber mold, the gas having a pressure higher than the isostatic pressure applied to the shaping rubber mold at the time when the shaping rubber mold begins to restore to its original state during the decompression step of the method. An apparatus for the said compression molding which is equipped with a specially designed pressure gas inletting device.