Patent GB-1488000-A (GB)
Title: Package for a stack of sheet materials
IPC: B65B25/14
Filed: 1973-12-07
Abstract: 1488000 A package for a stack of sheet materials AGFA-GEVAERT 29 Nov 1974 [7 Dec 1973] 56848/73 Heading B8C A package for packaging a stack of materials 11 in sheet form, e.g. photographic sheet films, comprises a first strip of sealable material 25, Fig. 6, wrapping a first part of the stack; a second strip of sealable material 26 wrapping the other part of the stack, the first and second strips 25, 26 being sealed together at 27, 28 in partly overlapping relationship so that edges of the strips are overlappingly sealed to each other strip in order to form a tube enclosing the stack and having loosely overlying edges; and a seal 24 (Fig. 7) at each other edge in order to close the tube hermetically. The stack of sheet material 11 has a pair of covers 12, 13 the two strips 25, 26 being made, e.g. of paperaluminium polyethylene laminate, and sealed together at 27, 28 in overlapping relationship to form loose marginal tear flaps. One of the protective covers 12, 13 may have either a row of perforations (22), Fig. 3a, not shown, or an incision (23), Fig. 3b, not shown. In the arrangement shown in Figs. 1, 2 the two strips of packaging material are formed of composite strips 14, 15 and 16, 17 and have seals at 18, 20 formed, e.g. by glueing or heat sealing, and which provide loose tear flaps. The strip 14, 15 extends over the front face of the stack 11 the strip 16, 17 sealed at 21 to the strip 14, 15, being wrapped around the bottom edge, the rear face, and the top edge of the stack, and the strip portion 16 being sealed at 19 in overlapping relationship to the strip portion 15. The side edges of the strips 14, 15 and 16, 17 are sealed at 24 to form an air-tight, moistureproof package. The seal 18 may be extended, Fig. 2, to secure the strips 14, 15 to the protective cover 12. In a modification of the last-described embodiment, Fig. 5, not shown, the narrow strip portion (15) extends over the narrow strip portion (16). The package may be placed in a box or enveloped in a supplementary wrapper. A combined package, Fig. 4, not shown, comprises a corrugated cardboard box (30) having a-slot (35) sealed by an adhesive tape (35). In a machine for forming the package, Fig. 6, a stack of sheets 11, Fig. 8a, is placed on sealed-together strip portions 25, 26 resting upon a flexible metal sheet 42 having openings 58 connected to a pipe 43 which is axially movable in a concave member 59 yieldably supported, by springs 51, 53, the pipe 43 being connected by a flexible conduit 44 to a vacuum source. Side supports 56, 57, mounted at 49, for lateral, sliding, movement, carry hinged folding leaves 40, 41. A pressure member 45 is urged downwardly to flex the stack 11 and plate 42 and press them into the concave member 59 which is then lowered to the position shown in Fig. 8b. The leaves 40, 41 are then rotated towards each other through an angle of 180 degrees to fold the strips 25, 26 around the stack 11 and the member 45 while simultaneously, the supports 56, 57 are moved against the sides of the stack 11, the seal 27 then being formed by lowering a sealing electrode 47 after the leaves 40, 41 have been retracted. The supports 56, 57 are then moved further inwardly so that the strips 25, 26 no longer closely fit around the stack 11 and the pressure member 45 can be retracted, the supports 56, 57 then being retracted so that the sides of the strips 25, 26 can be sealed together.