GB1320552A - Method and apparatus for flattening and taking off tubular plastics film made by the blowing process - Google Patents

Abstract

1320552 Flattening and forwarding tubular film WINDMOLLER & HOLSCHER 25 Sept 1970 [27 Sept 1969 18 March 1970 17 July 1970] 45831/70 Heading B5B Tubular film 1 from a stationary flowhead is flattened and forwarded for treatment in another stationary location using apparatus comprising flattening plates 2, squeeze rolls 11, 12 and a laterally offset film deflecting roller or rod 13 arranged parallel to the squeeze rolls all of which are mounted on a plate 3 which oscilates through 360 degrees about the tubular film axis on a shaft 5. At least three further deflecting rollers or rods 14, 17 and 20, located in planes parallel to that containing the first deflecting roller, are provided further downstream and are alternately spaced near to and remote from shaft 5. These rollers are arranged for independent oscillation about the film axis' In use, each rod oscillates with an angle which decreases with increase in distance from the flattening plates, the film being finally taken off by stationary rolls 23, 24. Shaft 5 is oscillated by a motor and oscillation of the other rollers may be derived directly from the movement of the film. Such oscillation may be positively intercoupled, e.g. by gears 25, 26, 28 or by a lever mechanism, e.g. spherically movable lazy tongs (Figs. 5 and 6, not shown). Variations in the length of film, contained in the apparatus caused by the oscillation (due to rollers 14 and 17 being offset by distance A from the shaft 5) may be compensated for by arranging a cam 40 on shaft 5, which cam is followed by the end 18<SP>1</SP> of mounting 18 of roller 17, whereby the lateral position of this roller is cyclically varied. The rollers or rods may be stationary rods having an anti-friction coating on the rotatable rollers having optionally, rotatable outer coverings e.g. as disclosed in Specification 1,281,478. When shaft 5 is in the central position of its oscillatory movement, as in Fig. 2, the rollers 13, 14, 17 and 20 may all be parallel. Figs. 2-4 are views along shaft 5, Fig. 3 being at 90 degrees displacement and Fig. 4 at 180 degrees displacement, relative to Fig. 2. Rollers 14 and 20 may also be arranged so that their axis intersect the axis of oscillation (Figs. 8-12, not shown).