Base board for packaging of food products

Abstract: A backing or carrier plate for noble food items such as salmon parts is traditionally a thin, stiff cardboard plate laminated with aluminium foil, which is imprinted with a noble colour lacquer such as "gold". There are serious problems connected with this layout, and the invention solves these problems in providing for the cardboard plates to be laminated with food grade plastic sheets on both sides, these sheets being left with their surfaces uncoated or unimprinted so as to still be food grade. The important colouring is arranged inside of the surface, e.g. by using an imprint in the negative on the sheet surface facing the cardboard plate or by using a coloured lamination glue.

Description: The present invention relates to a backing board to be employed at the packing of food products, preferably sides of salmon, fillets and whole salmon, whereby the product is placed on the backing board and thereafter vacuum packed in a plastic sheet, the backing board being made of cardboard laminated with sheet material at both sides. As food, salmon is regarded a noble kind of fish of high quality, and therefore, it is marketed in a package which correspondingly presents the product and also meets the sanitary demands. Thus, smoked sides of salmon and sliced fillets are typically packed fully stretched or spread on a so-called salmon board and are vacuum packed in a transparent plastic sheet printed with information and ornamentation, preferably multicoloured, but placed such that at least most of the salmon will be visible on the background of the salmon board. The salmon board is rectangular and a little larger than the salmon side and it is basically a piece of cardboard laminated with a lacquered aluminium foil. The quality demands to such salmon boards are high, but, on the other hand they are also required to be non-expensive. The upper surface of the aluminium foil layer is lacquered with a background colour which displays the salmon; typically a golden or black colour is chosen for the side carrying the salmon and a silver colour is used for the rear side. The salmon is laid directly on the lacquer, which is not particularly suitable. However, a main objection is raised against the aluminium foil itself, as such a foil is not approved for food packing purposes. Furthermore, it is difficult to print on aluminium foil due to poor adhesion, which may result in unwanted voids in the lacquer, whereby the salmon may come in direct contact with the aluminium, resulting in miscolouring of the salmon. Furthermore, the lacquer easily cracks by the subsequent freezing of the packed product as well as by bending of the cardboard. The salmon boards are cut out from larger sheets, and by the cutting and rounding of the edges aluminium dust will appear on the cardboard members, this being unfortunate due to a miscolouring of the salmon as mentioned above. According to GB-A-2,231,322 it is known to use a relatively thick core or base plate made of expanded polystyrene. At least one side of this plate, viz. the carrier side, is covered by a thin piece of carton, while this entire unit is mounted in a surrounding plastic sheet, preferably of polyethylene. The food product may thus be placed on a clean and food grade carrier surface, subject to a final wrapping in an exterior plastic film. Imprint such as a noble colour on the piece of carton will be visible through this wrapping film. The present invention seeks to provide an analogous carrier plate in a substantially cheaper and easier manner, still based on the use of a thin and stiff cardboard plate. The carrier plate according to the invention is defined as stated in claim 1. The plastic sheet first of all eliminates the problems connected with the use of aluminium foil. Furthermore, by the invention it is also possible to avoid that the food products get in touch with the lacquer, this being achievable without the presence of special carton pieces, viz. in connection with the lamination itself. Thus, the plate product is ready for use merely after lamination by the two plastic sheets, this conditioning an easy and cheap production. The colour imprint may be present on the inner side of at least the plastic sheet covering the carrier side of the cardboard plate, i.e. printed thereon in the negative. Such an imprint is easy to provide as a grouped print on a wide plastic web which can then be laminated to a corresponding cardboard web prior to the final products being stamped or cut out therefrom. Alternatively, in order to provide for a desired colouring, it is possible to make use of a dyed glue for the very lamination. Compared with the colouring by lacquering the upper surface of the plastic sheet a small difference in the hue of the colours may be experienced, but this is fully acceptable as the advantage is achieved that the food product can now be laid on an approved plastic film and not on a lacquer surface. The detailed choice of material for the plastic sheets will depend on the practical use of the invention; as examples can be mentioned polyethylene, polyester, polypropylene and polystyrene. The cardboard plate itself may be a stratified or laminated product. It will be appreciated that it may still be based on natural fibres (cellulose), as the plastic film coating will provide protection against intrusion of moisture into the surfaces.

Claims: A backing plate for the packing of food products, preferably salmon parts, and comprising a core plate having both opposed sides covered with food grade plastic sheet material and exhibiting a presentable colour, originating from dyestuff inside of the outer surface of the cover sheets, these outer surfaces being uncoated and unim-printed, characterized in that the core plate is of the cardboard type and in that the food grade plastic sheets are laminated directly onto the surfaces of the core plate such that the resulting surfaces still exhibit the colour of the said dyestuff. A backing plate according to claim 1, in which at least one of the opposed plastic sheets is colour imprinted in the negative on its surface facing the cardboard plate. A backing plate according to claim 1, in which at least one of the two plastic sheets are secured to the cardboard plate by means of a coloured lamination glue visible from the outside of this cover sheet. A method of manufacturing a backing plate according to claim 2, characterized in providing a wide plastic sheet web with grouped imprint for the coverage of a plurality of cardboard blanks, laminating this web to a side of a corresponding cardboard web with the imprint facing this web, and cutting the resulting web into individual backing plates.

Inventors: LARSEN STEEN, LARSEN, STEEN
Applicants: LARSEN STEEN, LARSEN, STEEN
Application year: 1993
Main classification: B65D65
IPC codes: B32B27, B65D65, B32B33, B32B29, B31F5, B32B7