| 摘要 |
PURPOSE:To continuously obtain a foamed body wherein the foamed cells are uniform and the foaming rate is high, by allowing a thermoplastic resin molded body to foam while it is being lowered vertically in a high temperature zone followed by heating by high frequency to complete the foaming. CONSTITUTION:A thermoplastic resin molded body 5 capable of foaming is fed into a foaming chamber 1 at a temperature at which the molded body 5 can be continuously extruded from an extruder 6, and while the molded body 5 is being vertically lowered through a high temperature zone in the foaming chamber 1 whose temperature is higher than the extrusion temperature, the molded body 5 is allowed to foam to obtain a foamed body 7. Then the foamed body 7 is fed into a heating chamber 2, where it is passed between plates 4 of a high frequency apparatus so as to complete the foaming thereby forming a stable foamed body 8. Then it is passed through support rolls 10, 11 to be cooled and solidified and then is taken up by take-up rolls 9 to obtain the intended foamed body. |
