| 摘要 |
PURPOSE:To obtain a crystalline polyolefin resin sheet or film, excellent in transparency, by a method wherein a sheet type material, extruded out of a T-die, is contacted closely onto a cooling roll and is cooled by cooling at from non-contacting surface side between the cooling roll during a period of time until generating a frost line. CONSTITUTION:Molten sheet, extruded out of a T-die, is contacted closely onto a first cooling roll 3 by an air knife 2 and is taken up to a take-up machine through a second cooling roll 4. The resin sheet, contacted with closely the first cooling roll 3, is cooled by cooling water 10 through a wide width slit 9 at a place before generating a frost line 5. The used cooling water is collected into a water reservoir 11 and is circulated by a refrigerating pump 12. In this case, a roll 13 is provided as an interfering and preventing device for preventing the cooling water from being blown off by the air of the air knife 2. A crystalline polyolefin resin sheet, manufactured by this method, is excellent in transparency and may be utilized as a transparent packing material. |
