GB1480970A - Apparatus and method for applying lids to containers - Google Patents

Abstract

1480970 Applying lids to containers R S CAWRSE 14 May 1975 20374/75 Heading B8C To apply lids 20 having a layer of heatactivated sealing material to containers A, the containers are moved stepwise on a conveyer B to a position below a polygonal-section mandrel C which rotates stepwise about a horizontal axis and around which lid-forming material 76, e.g. aluminium foil, is wound with the heatactivated layer outermost, the material 76 being held by vacuum to the mandrel and being heated by a heater 246 to soften the heat-activated material, a knife 88 cuts the material 76 to form separate lids, each container A is lifted in turn e.g. by reciprocating plates 98 so that its open end engages the heated lid on the bottom face of the mandrel, and then the heated lid is forced against the open end by air at superatmospheric pressure so that the lid adheres to the container as it is lowered, the air also serving to cool the heat-activated material. As shown containers A are fed from a magazine 50-54 four-abreast past a filling hopper 58 before arrival at the lidding position, additional knives 90 in this case being provided to cut the material 76 lengthwise into four strips. Depending on the rotary position of the mandrel faces, a manifold either connects passages 206, 212 in the mandrel C to a vacuum source, to maintain the material 76 on the mandrel, or to air at superatmospheric pressure to subsequently force the lids on to the containers. The sealed containers are subsequently extracted from the conveyer B on to a discharge table 108 by reciprocating extractor plates 102 and a pusher plate 106. Drive means for synchronizing operation of the apparatus is described, the drive means also controlling a slide valve (Fig. 10, not shown) for controlling the supply of vacuum and superatmospheric pressure to the passages 206, 212 via the manifold D. As shown in Fig. 1 the container A may have rounded corners 14 such that when a square or rectangular lid is applied, four pull tabs 24 are defined at the corners of the lid. The container A may be of paper, metal or plastics, e.g. polyurethane, PVC or polystyrene, and the lid 20 is preferably aluminium foil coated with a thermoplastic adhesive such as polyvinyl acetate, polyvinyl alcohol, acrylic or polyamide.