GB1224393A - Improvements in or relating to a method and apparatus for forming a pocketed web - Google Patents

Abstract

1,224,393. Moulding containers. C.W.VOGT. 7 May, 1968, No. 21446/68. Heading B5A. [Also in Division B8] An apparatus for forming sealed packages comprises a rotating drum 19 having a plurality of pocket-defining recesses 27 in its peripheral surface, means for supplying web-forming liquid to the periphery of said drum, means connected to the drum for sequentially drawing a vacuum in each recess to draw the liquid against the drum's peripheral surface and into the recesses, forming pockets in the web, and then venting the recesses to release the web. In one embodiment, Fig. 1, the web is formed from a curtain 59 of liquid falling from a tank 52. The drum 19 has one or more rows of recesses 27, Fig. 2, in step with which are apertures 48, Fig. 1, of a belt 47 which carries the newly-formed pocketed web between a belt of vacuum-producing units 67 and a set of orbiting filling units 75 preferably of the gaseous pressure differential type, after which the pockets are sealed with a web 85. Unused liquid is caught in a trough 55 and re-circulated, and the tank itself may be pressurized and thermostatically heated. The base of each drum recess 27 comprises a filter block 30, Fig. 2, connected via pipes 34 to orifices in the disc 24 supporting the drum. A valve plate 38 has two arcuate passages 42, 44, with which the apertures 37 communicate, the passage 42 being connected to a vacuum line and the passage 44 being connected either to a pressurized line or to the atmosphere. The belt 47 is preferably of metal, e.g. stainless steel, and may be coated with a sealing material, e.g. rubber. Holes 50 in the belt are engaged by pins 49 on the drum. The orifice (62) of the tank 52 is enlarged at points (63), Fig. 3 (not shown), above the ends of the recesses 27. Each filling unit 76, which may incorporate weighing means, comprises a vertically movable filling head connected to a hopper 81 by an extensible duct 82. As the filling units preferably create a partial vacuum in the web pockets, a similar vacuum is introduced beneath the web through filter blocks 70, Fig. 7, in the units 67, which are engaged with the aid of pin-and-slots 79, 80 with the filling units, and evacuated through channels 71, 72, and 83, therefrom. The cover web 85 may be pressure or heat sealed to the web 60. Individual packages may be severed from the web, or groups of four, which may be folded to form a square package. In another embodiment, Fig. 8, the endless belt 47 is replaced by a roll 91 of material 90, e.g. cardboard, of similar construction, and the drum 93 has notches 95 instead of pins. The web 90 is positioned on the drum by star wheels 96. The web 60 bonds itself to the web 90. In a further embodiment, Fig. 9, articles 109 to be packaged are conveyed on a web 108 beneath a newly-formed pocketed web 104, and on an endless belt 106. The webs are sealed by adhesives or heat, and the pockets 105 are shrunk beneath a heater 111. Individual packages are severed from the web.