Method and apparatus for deformation of a thermoplastic plate in a deep hollow body by low pressure and under aussschaltung of the non-woven fabric lines on the outside

摘要

PURPOSE:To finish the surface of a molded sheet article to be smooth by transferring the drag line formed on the outside surface of the preliminarily formed sheet to the inside surface of the molded sheet article. CONSTITUTION:A female die 1 provided with a concave molding die 2 containing a concave part 2a with a deep narrow cross section is opposed to the a preliminary molding plug 6 whereby a convex surface containing a projection 7a fitting in the female die 1 and corresponding to the concave part 2a is made fit in and approach the concave part 2. The resin sheet softened by heat is formed preliminarily on the surface of the convex die 7 of the molding plug 6 by vacuum suction and fitted in the female die 1, and the pressure air is sent from the inside of the molding plug 6 into the inside of the preliminarily formed sheet 13a, thereby the sheet 13a is pressed down on the surface of the concave die 2 and thus the drag line 15a formed on the upper end of the projection 7a is transferred fitly on the inside surface of the sheet 13a. By this method, the surface of the molded sheet article can be finished to be smooth.