ES349172A1 - Improvements in or relating to the Sealing of Cartons - Google Patents

Abstract

Apparatus for preheating adhesive on carton closure surfaces and then sealing the closure, comprises means to support a carton with adhesive coated sealing areas spaced from each other and to blow hot air into those areas, the support then moving the carton to a sealing position. In one embodiment for closing a filled carton having a hinged lid with front and side closure flaps, Fig. 2, the carton, as shown chain dotted, is fed between guides 20 to abut a detector 21. The latter causes a pusher to forward the carton against a further detector 23, initiating operation of a further pusher 10. The pusher 10 moves the carton on to the support 11, the lid having been previously folded down. During movement on to the support, guides 13 fold the side flaps so that they are finally in close proximity to the outside surfaces of wing portions of a triangular section duct 14. The leading closure flap is folded down to be close to the outside surface of the transverse duct section by means (not shown) and hot air is blown through apertures 15 to melt the adhesive. The support 11 then raises the carton into a close fitting cooled collar 16 which folds down and secures the flaps. The support descends and the next carton it raises ejects the completed one. Alternatively cartons may join a stack passing through vertical guides (not shown). In another embodiment, Figs. 4, 9, for closing flaps at both ends of tubular cartons, the latter are opened out into pockets formed by notches 40, 41 in discs 36, 37 of an intermittently moving turntable. During subsequent movements, all bottom flaps, except the outermost 32, are folded in and at one station 4 a wedge.shaped duct 44 is pivoted by arms 54, 55 and bell crank supports (51), Figs. 5, 6 (not shown), into position between the flap 23 and the underlying flap 30. Hot air is blown via a heater 49 and the duct through apertures 47 to melt the adhesive. During further movement, the flap 32 is folded down and secured and the carton passes to a filling station. It may be vibrated to settle the contents. The top is then closed by means identical with that forming the bottom closure. The carton opening and flap folding devices are conventional and not described. A coding device, also not described, may be provided. The apertures through which hot air is blown may be located to form a seal pattern and may produce a break in the seal to facilitate opening.