| 摘要 |
PURPOSE:To allow a planar body to expand freely so as to obtain a foamed body inexpensively without creasing it and without allowing a heating medium to adhere to it, by floating floats in a heating liquid medium tank, and putting on them a thermoplastic resin planar body capable of being foamed by heating, and foaming the planar body by heating. CONSTITUTION:The thermoplastic resin planar body 2 (hereinafter referred to as a parent plate) capable of being foamed by heating is continuously payed out from a drum 1, is put on a plurality of the floats 5 such as hollow glass balls floated on the liquid surface of the liquid heating medium heated to a temperature >= the foaming temperature of the parent plate 2 and contained in the tank 4, and is delivered in a direction shown by an arrow. The parent plate 2 is heated from below and also is heated from above by a surface heater 6 or the like positioned above the medium tank 4 so that the parent plate 2 is foamed to be expanded in all directions. The lateral expansion of the parent plate 2 takes place readily as the floats 5 can move freely on the liquid surface. When the expansion of the parent plate 2 is completed, the resulting foamed sheet 8 is passed between a pair of feed-off rolls 7, 7' and is reeled by a take-up machine 9. |
