| 摘要 |
PURPOSE:A mold in which the resin is freely foamed except at the part of side wall is employed, thus lowering the height in the pile of foamed vessels of a thermoplastic resin to make the storage advantageous and prevent the warpage at the neck part of the vessels. CONSTITUTION:A thermoplastic foaming sheet 1 is laid between molds 2 and 3 and formed by drawing. Then, the mold is tightly closed at the part near the neck and evacuated through fine holes 4 by vacuum pipe 5. Thus, the side wall part, which decides the height of the vessel when the vessels are piled for storage, is partially foamed and the other parts, as the surround of the neck, bottom and the rising part of the bottom, are freely foamed. The free foaming is shape regulated in the one surface of either mold 2 or 3 and the foamed products are always made to remain near the one mold, either 2 or 3. |
