Blown plastic film tubing prodn. appts. - has turning rods system with reflector points between lay-flat device and reeling station, diverting rollers with axially moving guides, etc.

摘要

Appts. has turning rods system with several deflector points, located between the lay-flat device and the reeling station. One deflector point has a stationary rod and/or a rotating roller to divert the oblique laid-flat film tubing. The diverting rollers used have guides parallel to their axes and the guides can move axially through the laid-flat tubing and be moved back to their starting position by devices at the end not enveloped by the tubing. A one diverting/guide point one turning rod or roller is replaced by a number of parallel rods or rollers which break up the total wrap-round of the film. In the lay-flat and traction area of a blown film machine film tubing flattened by rollers passes a parallel, but sideways displaced, guide roller to prevent escape of air from inside the tubing. The film then passes to a 1st deflector guide of two rollers where it is turned through 180 deg. in one plane. The rollers are each set at 45 deg., pref. 90 deg. The tubing next passes to a guide roller and a 2nd similar to turn the film through 180 deg., Again the film now meets turning guides set at 45 deg., to produce a similar direction change as before. ADVANTAGE - The layer out eliminates the substantial displacements which tend to arise in the guides.