| 摘要 |
PURPOSE:To make it possible to heat uniformly by providing the first preheating chamber and the second preheating chamber with a low temp. zone between them. CONSTITUTION:An intermediate part between the first preheating chamber 1 and the second preheating chamber 2 is made to be a low temp. zone 3 being open to atmosphere. A sheet-like molding 4 made of a thermoplastic resin with foamability is passed through an inlet 12 below the first preheating chamber 1 and is continuously transferred in the first preheating chamber 1 while it is elevated vertically under supported condition and after it is preheated up to the softening temp. by means of a heater 11, it is sent out in the low temp. zone 3 from an upper outlet 13. After both end parts are cooled down to a temp. lower than that of the central part in the atmosphere, it is transferred continuously in the second preheating chamber 2 through an inlet 23 while it is supported horizontally by means of a supporting body 21 and after it is perheated uniformly up to a temp. just before the foaming temp., it is transferred to a foaming oven. |
