| 摘要 |
PURPOSE: To provide heat-insulating and/or structural use dual wall moldings without the use of chlorofluorocarbons as a foaming agent by inserting a foamed preform between two heated thermoplastic resin sheets, then pressurizing it in a mold and binding the sheets on a rim. CONSTITUTION: A foamed preform 7 is preferably of a foamed polystyrol, impact-resistant foamed polystyrol, foamed polypropylene or impact-resistant foamed polypropylene. Two thermoplastic sheets 1, 2 which are miscible with the foamed preform 7 and preferably with 0.5-20 mm average thickness are deposited on hinges 3, 4 and are heated to a temperature level above a softening point. These sheets 1, 2 are transferred to a molding zone to arrange the foamed preform 7 between the sheets 1, 2 by a support 6. Next, a mold 8 is closed to softly press the sheets 1, 2. Consequently, the sheets 1, 2, on the rim, are adhered to each other to form a single heat-insulating hard structure. |
