| 摘要 |
PROBLEM TO BE SOLVED: To realize the efficient film making of a thermoplastic resin sheet, which is free from surface defect and has no difference between the physical properties at a drum contacting surface and at an air contacting surface, by a method wherein cooling waters having the specified temperatures are jetted against the air contacting surface of a sheet-like thermoplastic resin matter. SOLUTION: Water jetting from flat spraying nozzles 17-19 are started under the condition that the temperature of the air contacting surface of a sheet is lower than the melting point of resin by 25 deg.C or higher. At the same time, the difference between the temperature of the jetting water and that of the air contacting surface of the sheet is 125 deg.C or lower, preferably 100 deg.C or lower, further preferably 75 deg.C or lower. In response to the lowering of the surface temperature of the air contacting surface of the sheet, the difference between the temperature of the water to jet and that of the air contacting surface of the sheet at the respective nozzles is set to be 125 deg.C or lower so as to obtain a sheet having less surface defect. The temperature of the air contacting surface of the sheet at the separation from a rotary cooling drum 3 is set to be 110 deg.C or lower. |
