| 摘要 |
PURPOSE:To obtain the titled homogeneous film whose haze is low and gloss is high, by blowing, to a bulb heat has been obtained by melting and extruding a tubular body from an annular die, an air current within a chamber having a guide plate parallel to the die surface. CONSTITUTION:A tubular body that has been melted and extruded from the annular die 1 is inflated by applying internal pressure by forced air into the bulb 4, and after the bulb 4 is preliminarily cooled by a cooling air current blown via an air ring 2, the bulb is again exposed to a cooling air current within the chamber 3 having the guide plate 3a generally parallel to the die surface so that a solidifying line 5 is formed in the tubular bulb 4 at a position near the guide plate 3a. As the solidifying line 5 can be recognized as a line which lies between the opaque section and the transparent section of the bulb, the cooled and solidified bulb 4 is collapsed by guide plates 6 and is taken up by nip rolls 7 to obtain the intended film. |
