Patent GB-1191295-A (GB)
Title: Improvements in and relating to Packaging Containers, and a Method of Making Them
IPC: B65D5/06
Filed: 1967-10-26
Abstract: 1,191,295. Packaging. TETRA PAK A.B. 26 Oct., 1967 [3 Nov., 1966], No. 48802/67. Heading B8C. An enclosure containing liquid is formed from a length of tube of flexible material, such as plastics film, sealed at one end and has the internal surfaces of the length of tube at its other end brought together and sealed along a narrow zone extending across the full width of the tube and the ends of the sealed zone at the corners of the enclosure folded back into tucks or pleats formed in the sides of the enclosure. The enclosure is preferably accommodated in an outer sleeve or casing of comparatively stiff packaging material. In the arrangement shown a tube 1 of polyethylene foil is filled with a liquid to the level 3 (having previously been transversely sealed at 6) and is transversely sealed at 4 and 5 to produce a cushion-shaped completely closed and filled bag 7 suspended from the remainder of the tube. In this position the bag 7 is surrounded by four flaps 8, 9, 10, 11 so that the body of the bag is somewhat flattened. Two fingers 40, 41 are moved inwards to form tucks 50, 51 of W formation in the bag as shown in Fig. 3 and also to support the bag whilst it is severed from the rest of the tube 1. The fingers 40, 41 are then lowered so that the bag 7 is fed via a hopper 43 into a sleeve 12 positioned therebelow, the hopper 43 having slots 44, 45 to receive the fingers 40, 41. The sleeve 12 is of square cross-section with sides 13, 14, 15, 16 and base flaps 17, 18, 19, 20. The top of the sleeve 12 is to form a " striptop " by means of a concertina-fold construction formed of fold areas 25, 26, 27 separated by fold lines 23, 24 and having rib-shaped portions 28, 30. There are also ribs 32, 34 which extend above roof areas 21 and also further ribs 33, 35 which extend higher than ribs 28, 30, and which form the " strip-top " seal of the closed package. During lowering of the bag 7 into sleeve 12 the fingers 40, 41 come into contact with ribs 28, 30 and the latter glide along the fingers inwardly towards the central axis of sleeve 12 so that the folded ribs 28, 30 are inserted into the tucks 50, 51 of the bag 7. The remainder of fold areas follow the ribs 28, 30 and finally the ribs 32, 33 and 34, 35 are moved towards one another with the aid of a pair of blocks (not shown). During formation of the top the fingers 40, 41 are withdrawn leaving the bag 7 suspended on the folded-in portions of the top of sleeve 12. Prior to the formation of the top the ribs 28, 30; 32, 33 and 34, 35 have adhesive applied to their internal surfaces so that in the final formation of the package top the inside of ribs 28, 30 are affixed to portions of the bag 7 within the tucks 50, 51 and the ribs 32, 33 are affixed to ribs 34, 35. Also in conjunction with the final folding operation base flaps 17-20 are folded up and sealed. The package is opened by using the thumb and forefinger to fold outwards the fold areas 25, 27 and pressing together the edges which have been folded out. The straightening out of the rib 28 opens the sealing zone 5, which may have been previously weakened, of the bag 7 since the rib 28 is affixed to the outside of the sealed zone. Thus when the package is finally opened by pulling apart the rib portions (Fig. 7) the opening 60 will be surrounded by portions of the former sealing zone that adhere tightly to the sleeve.