Apparatus for flattening a blown foil tube of thermoplastic synthetic resin

摘要

In a foil blowing apparatus, the distribution of singularity in the flattened foil tube over the length of a roll in which the tube is coiled are distributed by a fold shifting device above the squeezing rollers at the top of the foil blowing unit. The fold shifting device has three sets of pivotal planes each formed by a deflecting roller and a turning bar and oriented so that the maximum angle between each approaching stretch of the flattened tube and a perpendicular to the turning bar is 30 DEG and the maximum angle of each departing stretch and the perpendicular to the turning bar is 30 DEG .