| 摘要 |
PURPOSE:To extrude film of large cooling effect and good quality at a high speed by a method wherein the 1st, the 2nd cooling air are blown about the tubular resin and in the 2nd blowing, the cooling air is discharged toward the opposite direction of the resin extruding direction. CONSTITUTION:The 1st air ring 6 is located at the neighborhood of the upper surface of the extrusion die 1 so that the 1st cooling air is blown from the air outlet 6A. Then, the 2nd air ring 7 is located at the neighborhood of this film expansion completion point and the air outlet 7A faces the opposite side of the extruding direction of resin. The cooling air discharged from the 1st air ring 6 is blown against the tubular resin 4 of a high temperature, heat-exchanged, and heated. However, this cooling air collides with the downward cooling air from the 2nd air ring 7, is discharged from the periphery of the tubular resin 4, while the tubular resin 4 is always exposed to cooling air of a low temperature. Therefore, film of large cooling effect and good quality can be extruded at a high speed. |
