| 摘要 |
PURPOSE:To manufacture a foam having no wave and high quality continuously by successively passing an expansible thermoplastic resin sheet-shaped molding in a heating tank using a heating medium consisting of a low melting-point metal. CONSTITUTION:A thermoplastic resin sheet-shaped molding S having foamed capability fed from feed rolls 1 is introduced into a preheating tank 7, in which a liquefied heating medium N composed of a low melting-point metal, specific gravity thereof is larger than the molding S, is stored, through a guide roll 2. The molding is immersed in the heating medium N, and preheated to approximately 100-200 deg.C until it reaches to a foaming heating tank 8 side end in a belt conveyor 5. When the molding S passes through the foaming heating tank 9 side end in the belt conveyor 5, the molding floats on the surface of the heating medium N in the preheating tank 7 by the buoyancy of the heating medium N, and enters into a foaming heating tank 8. The molding S is heated by heat transfer from the heating medium N and thermal projection from a far infrared heater 20 from the surface side and foamed, thus manufacturing a foam Sa having predetermined density. The foam Sa is cooled by a cooling device 21 and cooling rolls 22, and wound as a product. |
