Method of production of precision casting moulds by plaster moulding, casting and use of plaster moulds

摘要

Process for the production of casting parts with well-defined reproduction of detail and a great accuracy of measurement using the gypsum-form process. The pattern to be copied is equipped with a drainage apparatus, having at least one channel extending outside the molding box, and the molding material is poured into the mold and solidified. After the pattern is removed from the solidified mold by the introduction of compressed gas, the water of the solidified material is removed from, and after drying the mold is connected to a vacuum line and evacuated. The molten mass is then poured into the mold while the vacuum is maintained and solidified.