| 摘要 |
A tubular film process wherein molten resin is extruded from an extrusion die into a tubular resin, blown by an internal pressure, cooling air is discharged at least at a point between the vicinity of the extrusion die and the vicinity of a bubble expansion ending point in a direction of the extrusion of the resin and in a direction opposite to the extrusion of the resin to, thereby cool the tubular resin, and the tubular resin is continuously taken up upon being cooled and solidified. The cooling air has higher flow rate in the extrusion direction. The cooling air is discharged not only in the direction of the extrusion of the resin but also in the direction opposite to the extrusion of the resin, whereby hot air stream is prevented from accompanying the flow of the resin, thus enabling to effectively cool the tubular resin. |
