US Patent 7096919 Sublimation pattern casting method

An evaporative pattern casting process in which a casting process plan capable of attaining the optimal discharge of generated gas can easily be decided. The evaporative pattern casting process can cast a product, and includes pouring a molten metal in a mold in which a pattern made of an expanded synthetic resin is embedded in molding sand, and evaporating the pattern with the molten metal, while gas generated by evaporation of the pattern is discharged outside the mold through a discharging passage including discharged gas suppressing device. The ventilation of the discharging passage is controlled on the basis of the material, the shape of the pattern, the kind of the molten metal, and the temperature of the molten metal.