METHOD FOR FORMING SHELL MOLDING MATERIAL

PURPOSE:To uniformly ram molding material over the whole forming face and to enable the forming by using mold member providing elastic member and the forming face, making negative pressure between the both members, bending the elastic member under condition of along the forming face and forming the molding material under inter-pressing. CONSTITUTION:The mold member 1 is descended and the lower end of the outer flask 6 thereof is abutted on margin part 20 of vinyl sheet 2 spread out of the molding material 3 and by sucking from an air suction hole 4a, the pressure in a suction box 4 is reduced. The margin part 2a of the sheet 2 by suction force acting to suction groove 9a through venting holes 9b, 9b... is stuck to the lower face of the outer flask 6, and the part surrounded with the sheet 2 and the mold member 1 is made to the negative pressure and the sheet 2 is bent along the forming face 5b of the mold member 1. Then, the molding material 3 is formed under inter-pressing with the sheet 2 and the forming face 5b as shell-state along the forming face 5b. Successively, the mold member 1 is overturned and by penetrating carbon dioxide gas into the molding material 3, hardened shell is formed. After that, the shell is separated from the mold and the sheet 2 is stripped, to obtain the mold 3'.