Gas-proof packaging.

p0001The invention relates to a gas-tight packaging for particular photosensitive and heatable in packaging foods, consisting of a closable at least in a marginal region by welding or sealing bag made of a plastic film which is laminated on its outer side with an aluminum foil or coated with a metallized plastic film ,

p0002Food with high sensitivity, the same shall by means of the packaging material to be protected for a longer storage period from the influence of external oxygen, hydrogen, flavorings or of losing, are packaged using aluminum foils or metallized plastic films that have excellent product protection qualities. The packaging usually consists of a bag with a rectangular base, which is closed on at least three side edges by welding or sealing.

p0003The packaging or the bag consists for example of a two-layer laminated film, for example, polyethylene and aluminum, which are firmly and inextricably by a laminating adhesive. In the formation of the bag or packaging is the two polyethylene layers face each other, as have the same good sealing properties. The outer surface of the two-layer laminated film, so umfolie the aluminum layer bzw.-, is laminated with a PETP or polypropylene film which also bzw.- layer to the aluminum foil fixed by a laminating adhesive and is inextricably linked.

p0004Such a package with an aluminum foil, however, when they are used for foods which are heated prior to consumption in the package, the disadvantage that a heating of food by microwaves is not possible. Although there are microwave ovenable packaging known which consist of material combinations without aluminum foil. Such packages, however, as already stated above, is not needed for some food protection.

p0005The invention is therefore based on the object to provide a gas-tight packaging for particularly sensitive and heatable in packaging food, on the one hand reaches the required protective function, but on the other hand offers the possibility that the food can be heated by microwaves in the packaging.

p0006To achieve this object it is proposed according to the invention in a package of the type described above, that the aluminum foil or metallized plastic film extends at least in a part of the closed border area on the plastic film and releasably connected to the same by a peelable adhesive lamina. In this case, then, the inner plastic film for example, a polyethylene-polypropylene duplex layer, the polypropylene layer of the aluminum foil and the metallised plastic film facing.

p0007In a packaging such, it is possible the entire surface, the aluminum foil prior to heating by Mirko waves - without the actual packaging is damaged or destroyed - to remove, and then to heat the food in the package by microwaves. In the over the plastic protruding or projecting region, the aluminum foil can be easily detected and abgepeelt entire surface of the inner plastic film or the internal network.

p0008Other features of a packaging according to the invention are described in claims 2 - disclosed. 6

p0009The invention is explained in more detail with reference to an embodiment shown in a drawing. show case<ul><li>Fig. 1 is a plan view of the packaging according to the invention,</li><li>Fig. 2 is an enlarged, not to scale, sectional view of a multilayer film of the packaging of FIG. 1 and</li><li>Fig. 3 is not to scale a section through the head region of the packaging in FIG. 1.</li></ul>

p0010In Fig. 1 of the drawings a package for photosensitive and heatable food in the packaging shown, which consists of a bag 1. Here, the pouch 1 2 (Fig. 2) is formed in this embodiment of two multilayer films, which have a rectangular base.

p0011Each multilayer film 2 consists in this embodiment of a polyethylene layer 3, which is fixed via a lamination adhesive layer 4 and permanently connected to a polypropylene layer. 5 On the free surface of polyproplen layer 5, an aluminum foil 7 is arranged by means of a special laminating adhesive 6, which in turn is permanently connected and a laminating adhesive layer 8 with a polyester layer. 9 In this embodiment, the aluminum foil 7 and the firmly bonded polyester layers 9 have a larger footprint than the from the polyethylene layer 3 and the polypropylene layer 5 existing plastic 3.5. How can the Figures 1 and 3 clearly shows the protruding aluminum foil 7 with the polyester layers 9 at one edge on the plastic film 3.5 out.

p0012To form the bag 1, two such multilayer films 2 now be superposed so that the polyethylene layers 5 of the two multilayer films 2 are opposite and - after filling or loading food - at its entire edge 10 by sealing are interconnected such that the closed bag 1 is formed. The FIG. 3 shows clearly that the aluminum foils are 7 completely free, so do not interconnected with the polyester layer 9 both multilayer films 2 in the region of the upper edge 11 of the bag 1. To link the polypropylene layer 5 with the aluminum foil 7 a special laminating adhesive 6, as mentioned above, is used which is peelable, ie, that laminating adhesive 6 is the possibility that the aluminum foil 7 with the polyester layer 9 full area of the group consisting of polyethylene-polypropylene layer 3 and layer 5 plastic film can be peeled off or removed. To this end, the two aluminum foils 7 are detected and removed with the polyester layer 9 in its free edge region 11th

p0013The above-described packaging process ensures that the food contained therein are protected from light and on the other hand after removal of the aluminum foil 7 can be easily heated by microwaves.

p0014Amendment of the illustrated embodiment Bespieles it is possible to use other plastic layers. However, it must also be ensured that the laminating adhesive 6 between a plastic film and the aluminum foil 7 and the metallized plastic film is peelable and removal or removal of the aluminum foil 7 and the metallized plastic film permits. However, the facing layers of the multilayer film 2 must be made of such a plastic, which allows the formation of a package or a bag 1 by welding or sealing.