GB1260367A - Method and apparatus for applying shrink-wrap sleeves about articles - Google Patents

Abstract

1,260,367. Packaging machines. UNILEVER Ltd. 20 March, 1969 [20 March, 1968], No. 14573/69. Headings B8A and B8C. A method of applying sleeves 21 to tapering plastics tubs 1 comprises supporting the tubs above a conveyer belt 3 and between two vertical films 5, 6 so that the lower edges of the films project below the tubs, welding and separating the films intermittently between a pair of tubs and then heat-shrinking the sleeve thus formed on each tub. The tubs are supported on carriers 2 slidably mounted on the conveyer belt 3 which takes them to a sleeve applying station having swingable stops 19b, 19, l9a. The stops 19 hold a tub whilst the sleeve is being laid around it by the welding and separating device, the stops 19a hold stationary the tub which has just passed the welding and separating device so that the newly formed seam is not under load, and the stops 19b hold back the fourth tub whilst the third tub is moving into the welding and separating device. The welding and separating device comprises retaining means 27 for compressing the film and a heated resistance welding thread lying on a flat non-stick surface. The device may form two welds and two cuts which follow the profiles of the tubs. The material between the cuts is removed by a pair of pliers 22 mounted on a shaft 30 having an eccentric disc for opening and closing the pliers. The films are pulled from reels 9, 10 by driven rollers 7, 8 and a loose loop A is formed after the rollers 7, 8 by an elastic thread. The films are prevented from collapsing by air jets 23, 24. Photo-electric cells 11, 12 responsive to printing or registration marks on the film control the length of film taken each time from the reels 9, 10.