CASTING METHOD USING LOST FOAM PATTERN

PURPOSE:To prevent the development of surface defect in a product by supplying solvent through communicating passage at a part of lost foam pattern corresponding to place, at where the surface defect is easily developed, dissolving and losting a part of the pattern and successively executing casting. CONSTITUTION:The lost foam pattern 2 is set on sand mold 8 in a flask 1 and also pipes 7 are set on facing agent film 6 on the final molten metal running surface 3 in the pattern 2, which the carbon residue is easily developed. Successively, the sand is packed to the upper end of a flask 1 and the sand is sammed by executing the vibration and hardened under reducing the pressure. The solvent for dissolving the pattern 2 is supplied to the final molten metal running surface 3 from the pipes 7 and a part of the pattern 2 is dissolved and vaporized. At the time of pouring the molten metal 9, as a part of the pattern 2 is lost near the molten metal running surface 3, the development of the carbon residue is eliminated and a part of gas is exhausted from the pipes 7. Therefore, the development of the surface defect in the product caused by the carbon residue can be prevented.