| 摘要 |
Film in the extruded bubble (1) is cooled by sprays (16, 33) in a cooling zone (30) using water, preferably at 0 to 25 [deg]C. Just downstream of the cooling zone (30) is a heat treatment zone (40) with sprays (43) using water at least 20 [deg] hotter than in the cooling zone, e.g. at 50 to 70 [deg]C. The treatment zones (30, 40) include sizing rings (31, 41) and the pressure in the interior of the bubble is greater than on the outside, e.g. by 10 to 30 mbar. An independent claim is included for the process of blow molding film by this method followed by squeezing (24) or folding it flat and drawing the resultant tube. |
