Patent GB-1393277-A (GB)
Title: Food package and method of making same
IPC: B65B31/00
Filed: 1972-05-05
Abstract: 1393277 Food packages OSCAR MAYER & CO Inc 5 May 1972 [9 June 1971] 21100/72 Heading B8C A method of packaging a plurality of linktype meat product integers in side-by-side relationship between first and second layers of packaging material includes the steps of preforming at least said first layer of packaging material beyond the elastic limit thereof to the general contour of each said link-type meat product integers to be packaged and to an extent sufficient to engage said meat product integers without exerting forces there-against in the finished package so as to at least minimize syneresis of juices, placing meat product integers on said first layer of packaging material, placing the second layer of packaging material in overlying relationship, bringing said first and second layers of packaging material into engagement with each other and about said meat product integers, evacuating gases by suction from the area surrounding the meat product integers between the first and second layers of packaging material thereby drawing said layers into product conforming relationship with said meat product integers, and forming a hermetic seal which completely encloses the meat product integers between the first and second layers of packaging material. Apparatus for carrying out the method, Figs. 1A, 1B, comprises a plurality of film extruders 27-29 and 30-32 which extrude laminae 33-35 and 36-38 respectively which pass through associated pairs of rollers 42, 43 in a bath 41 which contains water at a temperature approximately of between 35‹ and 60‹F. to supercool the films, before they pass successively to a package forming component 24, a heater 25, and a combination labelling and trimming mechanism 26. The laminae 33, 35 of the lower layer 39 and the lamina 38 of the upper layer 40 are formed of vinylidene chloride-vinyl chloride copolymer and the laminae 34 and 36, 37 of the layers 39, 40 respectively are formed of E.V.A. When supercooled in the bath 41 the vinylidene chloride-vinyl chloride copolymer films conform, without tension, to the shape of the product and co-operate readily with a film of E.V.A. to form a peelable, or break-away, seal. Series of lower and upper die platens 50, 51, mounted respectively on lower and upper continuous conveyers 49, 50 mate with each other and form a chain of product-containing packages 53 which, before being labelled and separated at 26, are heated, at 25, to a temperature of approximately 160‹F. to effect crystallization of the polyvinylidene chloride laminae 33, 35, 38. At least one of the die platens such as 50a, Fig. 2, is grooved at 59 to conform to the shape of the product so that the corresponding layer of material 39a is similarly preformed beyond its elastic limit by vacuum and so that, when it is subsequently combined with the upper layer 40a by the application of an associated upper platen 52a, having a single recess 60, to form a package, the material of the latter will not exert a compression force upon the product. A vacuum is then drawn on the inside of the package and maintained while the exterior of the package is vented to atmosphere. A completed package, Fig. 7, has insert pull tabs 84, 86. In another embodiment, Figs. 4, 5 not shown, both upper and lower platens of each package are configured to the shape of the product to be packaged, the latter comprising wieners in side-toside, spaced-apart, relationship. In this manner both of the packaging layers are preformed beyond their elastic limits and the weiners in each package are individually sealed, and have separation perforations therebetween.