| 摘要 |
Extruded plastic strip(2) passes between first(4) and second(5) polishing rolls, followed by a cooling roll. Cooling chambers(6,6') located opposite the surface of the cooled roll at the area where the plastic strip passes over the roll direct cooling air at the film strip. The first(4) and/or second(5) polishing rolls may be cooled and the second may simultaneously act as a cooling roll. Air inlets(7) and outlets(8) of the cooling chambers(6,6') ensure that incoming air is directed at the film surface and then flows to the outlet. Air reaches the film strip through an opening(10) in the cooling chamber which extends around part of the cooled roll periphery. An adjustable gap(11) between the chamber and film on the roll surface enables incoming air to flow along the strip surface. Cooling air at the air inlet is 10-50[deg]C, preferably 10-45[deg]C. Two or more cooling air chambers may be located one behind the other. Air in the first chamber is at 5-40[deg]C, preferably 10-35[deg]C and in the second chamber is at 10-50[deg]C, preferably 15-45[deg]C. |
