| 摘要 |
<p>PROBLEM TO BE SOLVED: To uniformly control the thickness of a resin film by spraying the air before an extrusion molded resin sheet arrives at a frost line, and controlling the pressure of the air and/or the spraying area in this case. SOLUTION: Since a resin sheet S is still at the temperature higher than the softening point immediately after the sheet S is extruded, it is brought into contact with a chill roll 14 to be quickly cooled, and the air is brought into contact with the sheet S before the sheet S is at the temperature higher than the softening temperature, thereby regulating the thickness of the resin film. To this end, the air is sprayed to the sheet S from the air nozzle 20 provided at the upstream side from the frost line. A thicknessmeter 17 is provided before a winding roll 18, and the pressure of the air injected from the nozzle 20 and/or spraying interval are regulated in response to the difference (measured value of film thickness-object value of film thickness) by a feedback system. As a result, it makes it possible to easily control the film to a desired thickness.</p> |
