EP0481996B1 - Dish for sales packaging of foodstuffs - Google Patents

Abstract

Described is a dish for use in the sales packaging of food such as uncooked meat or fruit. The dish has a bottom with a side-wall extending round the edge plus, on the bottom, an absorbent layer of hygienic cellulose tissue. The dish is made up of three layers (20, 24, 26), an underneath layer (20), made of fibrous material, in particular wood pulp, paper material or half stuff and preferably cardboard, which forms the outside surface and defines the shape of the dish, a minimum-thickness intermediate layer (24) made of greaseproof water-repellent material, e.g. a film of polyethylene or varnish, and an absorbent uppermost layer (26) made of cellulose tissue which forms the inside surface of the dish.

Description

The invention relates to a tray for food sales packages, e.g. B. fresh meat or fruit, with a bottom and a peripheral edge and with an absorbent layer on the floor made of food-hygienic cellulose tissue.

Different trays are known for the packaging of foodstuffs, in particular in the self-service area of the trade. The shell of the type mentioned consists of closed-cell plastic foam, for. B. Styrofoam (registered trademark), the absorbent layer of cellulose tissue is placed on its bottom without a separate connection. After filling with a food that is placed on the absorbent layer, a thin, stretchable film is generally placed over the food and, for example, welded below, under the floor. This film holds the absorbent layer in place. The absorbent layer has the task of absorbing and retaining moisture originating from the foodstuff, so that, for example, when fresh meat or fruit is packaged, it does not happen that liquid (visible) can accumulate on the top of the waterproof floor. Since the absorbent layer is in direct contact with the food, it must be made from a food-hygienic material.

The disadvantage of this previously known foam shell with cellulose cut as an insert is the disposal. Stypopor or other foam cannot be removed without problems. For reasons of stability, the foam tray must have a certain thickness of several millimeters in order to prevent it from breaking when packaging foodstuffs that can weigh up to a few kilograms. This means that each individual foam shell has a certain volume. In addition, since the number of trays to be shredded is extremely large, the use of foam trays for sales packages results in a relatively large amount of waste, for which problem-free disposal has so far not been satisfactory.

In addition to the foam shell, a so-called groundwood bowl is known, it is in one piece. The shell is absorbent due to the wood pulp material. This in turn has the disadvantage that the moisture can penetrate through the entire material thickness, so that the shell can soak through, and it then loses its mechanical stability. For reasons of hygiene, the wood pulp used must be treated properly in terms of food hygiene, which in practice can only be achieved by using pure wood polishing over the entire thickness. For this reason, the wood pulp bowl is generally more expensive than the foam bowl with an insert in the form of a cellulose blank.

Finally, coated boxes are known as trays for the use of sales packages. They are not absorbent; metal foils, in particular aluminum foils, are often used as a coating. Under these circumstances, there is no problem with disposal.

Proceeding from this, the object of the invention is to provide a tray for sales packs which, on the one hand, can be disposed of without environmental problems, in particular can be burned, and on the other hand maintains its mechanical stability even when there is a large amount of moisture from the packaged food and can finally be produced inexpensively.

This object is achieved on the basis of the shell of the type mentioned at the outset in that it is composed of three layers, namely a lower, shaping layer of fibrous material which forms the outer surface, in particular wood pulp, paper or semi-pulp and preferably cardboard, one in comparison to the other layers thinly formed intermediate layer made of a fat-tight, water-repellent material, for. B. a polyethylene or lacquer layer and an upper, absorbent layer of cellulose tissue forming the inner surface.

The lower, shaping layer is both protected from moisture and hygienically separated by the intermediate layer. The lower layer can therefore be made of relatively inexpensive, not hygienically pretreated Fiber material exist; for example, waste paper can be used. Due to the intermediate layer, the product to be packaged does not come into contact with the lower, load-bearing layer, so that the latter can only be designed for optimal carrying properties and dimensional stability with the least possible use of material, without taking into account weakening stability when moistened or requirements for food required sterility of the material must be provided.

The intermediate layer is made as thin as possible, it has no mechanical tasks to perform, so that it can be designed with regard to its blocking effect on fat and water on the one hand and germs on the other. The intermediate layer should be stretchable, so that no cracks or perforations occur when the shell is deformed, as occurs when handling, for example during the purchase, when placed in a sales car, etc. Furthermore, in the case of a stretchable film, the shell can be shaped from the three-layer blank without this problem giving rise to sealing problems.

The upper cellulose tissue film, which comes into contact with the packaged food, on the one hand conveys a visually appealing image of the inner surface that is generally visible when purchased. Its thickness is dimensioned sufficiently so that the quantities of liquid obtained in the typical foods to be packaged can be safely absorbed. The layer of cellulose tissue consists of long-fiber, glued cellulose (airlight tissue), which is bleached using the dry process. Such material is also used for paper handkerchiefs, serviettes and the like. This upper layer is preferably shaped, for example by fine embossing, so that the food comes into contact with the surface only in places.

The tray according to the invention, created from a three-layer blank, can be disposed of without any problems. The two outer layers, the upper and the lower layer, are made from natural products and can therefore be removed without damaging the environment. The intermediate layer is thin on the one hand, so that it is not very important in terms of volume, on the other hand it can be made of a material, for example polyethylene, which enables environmentally friendly disposal. As a result, the entire shell is inexpensive to dispose of.

Trays for sales packs of the type in question are basically only suitable for single use. Multiple use stands in the way of the high expenditure for a food hygiene-perfect cleaning and restoration of the upper layer which comes into contact with food. This applies generally to all of the shells described here.

In general, the lower layer is significantly thicker than the other two layers. The thickness of the intermediate layer is generally less than 10 micrometers, the material thickness of the layer of cellulose tissue is usually between 20 and 200 micrometers and is only a little thicker for special applications, namely foods to be packaged with a high level of liquid. The thickness of the lower layer is typically several tenths of a millimeter.

In a preferred development, the base consists of over 50%, preferably up to 100%, of waste paper. Waste paper is produced in relatively large quantities. Its lower quality compared to fresh material can be compensated for by greater material thickness of the lower layer, sufficient binder addition, etc. In this respect, the invention enables a new area of application for refurbished waste paper.

In a preferred development of the invention, the adjacent layers are either glued to one another, preference being given to point gluing, or connected to one another by means of embossing. Sufficient cohesion of the three layers is achieved in each case. Sufficient cohesion is a connection of the layers, in which they do not separate from each other during normal use of the shell, at most gently diverge at the common edge. This means that in the shell according to the invention two adjacent layers can in general be separated from one another with suitable aids without the two layers losing their function, in particular being damaged. Embossing has the advantage that no additional adhesive is required.

In the case of spot bonding, the amount of adhesive to be used is as small as possible. A material that has no environmentally harmful properties is used as the adhesive.

In the manufacture of the shell, the three layers are first connected to one another and the blanks for the shells are punched out from the web-like material thus obtained, which can be wound up in roll form. The shells are produced from these blanks in a manner known per se either by embossing or by folding up the edges and gluing or plugging in tabs provided on the edges.

In the shells according to the invention, the lower layer forms the entire outer surface of the shell, the inner layer made of cellulose tissue forms the entire inner surface. The layer structure can only be seen on the cut edges of the blank. The intermediate layer is practically not visible, at most you can recognize it by the punched edges (cut edges).

Finally, in an advantageous development, a closed container can be produced from two shells according to the invention, which are integrally connected to one another and can be moved around a kink region between an open and a closed position. Such containers can replace sales packs in the fast food sector, which at the moment consist almost entirely of foam.

• Fig. 1 ein Schnittbild durch eine formgeprägte Schale gemäß der Erfindung,
• Fig. 2 das Detail II aus Fig. 1 in erheblich vergrößerter Darstellung und
• Fig. 3 eine Darstellung entsprechend Figur 2 eines zweiten Ausführungsbeispiels

Further advantages and features of the invention emerge from the remaining claims and the following description of a non-restrictive embodiment of the invention, which is explained in more detail with reference to the drawing. In this show:

• 1 is a sectional view through a molded shell according to the invention,
• Fig. 2 shows the detail II of FIG. 1 in a significantly enlarged representation and
• Fig. 3 is an illustration corresponding to Figure 2 of a second embodiment

1 shows a shell, which is embossed in one piece from a blank and is known per se, which according to the invention is produced in a three-layer structure, as can be seen from FIG. 2.

A lower layer 20, with its outer surface visible downward, forms an outer surface of the shell. This layer is constructed from the least expensive fiber material so that it determines the stability of the entire shell. A fibrous material, for example wood pulp, paper or semi-pulp, wrapping paper or cardboard, is used as the fiber material, generally papers containing wood pulp or waste paper. Natural materials are preferred, although synthetic fibers can also be used. The adhesives known for pulp and in the paper industry, in particular resins, are used for sizing. The thickness of the lower layer 20 is a few tenths of a millimeter and is selected in accordance with the material properties, the size and the load-bearing capacity of the shell. The lower layer can also consist of corrugated cardboard.

In the exemplary embodiment shown, an intermediate layer 24 and an upper layer 26 are connected to one another as a preliminary product. The top layer 26 consists of fluffy paper, a so-called air light tissue, as is known as tissue, tissue and napkin paper made of cellulose. Long-fiber pulp is used, which gives the upper layer 26 a matt appearance. The thickness of the top layer 26 is typically between 20 and 200 microns. The upper layer 26 is made of hygienically perfect material (cellulose and adhesive), it comes into contact with the food to be packaged in the practical use of the tray according to the invention. Their absorbency is dimensioned so that the amounts of liquid typically produced in the packaged food can be sucked up safely and without problems.

The intermediate layer acts as a barrier layer between the upper layer 26 and the lower layer 20, it is neither fat nor water nor germs let through. Like the other layers, the material is selected in such a way that environmentally friendly disposal of the entire shell is possible. Although it is fundamentally possible to produce the three-layer web from which the cuts for the shell are made from three individual, separate layers in one work step, it is preferred to initially change the intermediate layer, preferably with the upper layer 26, in a modified (here (not shown) but also to be connected first to the lower layer 20 and then to glue on the missing layer or to connect it to the created double layer by embossing.

In the exemplary embodiment discussed here, a very thin polyethylene film is applied as an intermediate layer 24 on one side to a web of smooth cellulose tissue. The double layer created in this way is mechanically embossed, as can be seen from FIG. 2. However, such an embossing is not necessary, it can also be omitted. By means of point gluing, an adhesive is applied point by point to the outer surface of the intermediate film (or alternatively to the upper side of the lower layer 20) and the three layers 20, 24, 26 are thereby connected to one another. It has proven to be advantageous to connect the intermediate layer 24 so permanently to the upper layer 26 of cellulose tissue that it is possible to separate the two layers, but it is basically difficult to accomplish. In contrast, the connection (corresponding to the exemplary embodiment shown) between this two-layer structure 24, 26 and the lower layer 20 is only so weak that no separation occurs during normal handling. This saves glue, which on the one hand leads to a cost reduction, but on the other hand also leads to fewer problems in waste disposal.

In the exemplary embodiment shown (see FIG. 2) there is a distance between this and the lower layer 20 due to the shape embossing of the combined layer 24, 26; the connection is made only in the region of pronounced humps. On the one hand, this facilitates punctiform gluing, on the other hand the soft, fluffy structure of the top is improved.

Instead of an intermediate layer made of polyethylene, other materials that ensure sufficient grease and water tightness can also be used. In principle, an intermediate layer 24 made of wax, a suitable lacquer or the like is possible.

It has proven to be very advantageous to cut out not only one shell, but two blanks for shells connected in the area of a folding line. In this way, foldable containers can be created, as are currently frequently used in the fast food sector, but the known containers are made of foam plastic. As with the previously known foam plastic containers, a closing flap can be provided on the side of the one shell opposite the crease line and a corresponding receiving device on the other shell. In fast food packaging of this type, the lower layer 20 is also designed with regard to optimal thermal insulation, for example corrugated cardboard is suitable here, which offers good thermal insulation due to the high, stored air volume.

In the exemplary embodiment according to FIG. 3, the upper layer 26 is covered by a thin, water-permeable and moisture-repellent covering 28 in the form of a PE or latex film (or a film made of a suitable other material). The thickness of this pad 28 is between five and twenty microns. The pad 28 avoids direct contact of the food with the absorbent material of the top layer, it prevents it from sticking to it or entraining fibers when food is removed therefrom. The absorbency of the upper layer 26 is maintained due to the water permeability of the pad 28. The permeability of the pad 28 is matched to the respective product to be packaged in such a way that no amount of liquid can accumulate on the pad 28. Rather, the product always remains dry on the pad 28. Furthermore, the pad 28 is water-repellent and does not swell itself, it has as little liability as possible to the products to be packed. This ensures that the product to be packaged does not stick to the support. The support 28 is preferably embossed, for example with a micro corrugation, which can also be designed crosswise or with small projections (see Figure 3). This will make the Contact area with the product to be packaged is reduced and extensive contact of the product to be packaged with the support 28 is avoided, so that small openings 30 or micro-grooves for draining liquid always remain free.

The overlay can be applied as a perforated PE film to the upper layer 26 in a suitable manner, for example glued, embossed or the like. In an alternative, latex is sprayed onto the top layer 26 so that the layer obtained adheres and is still permeable (perforated). Finally, a PE film can be applied to the top layer 26 through a slot die; the water permeability is brought about by suitable additives in the film that burst open after the casting process.

The openings 30 in the support 28 are so small that they cannot be recognized by the eye. The openings 30 can be formed by needle perforation, as capillary openings, as micro-slits, through the molding or the like. However, this does not preclude major training. The layers 20, 24, 26 and the support 28 are connected to one another over the entire surface.

The term cellulose tissue is understood to mean a fibrous layer of cellulose. The pulp can be long-fiber, such as in the case of napkins, but it can also be short-fiber, such as in the case of toilet paper.

Claims (9)

1. Sales tray packaging for foods, e.g. fresh meat or fruit, with a floor and peripheral edge and an absorbent layer, made of hygienic wood pulp suitable for contact with foodstuffs, which is located on the floor of the tray,
   characterised by the fact that the tray is composed of three layers (20, 24, 26), namely a layer forming the exterior surface and bottom of the tray (20); this layer gives the tray its shape and is made of fibrous material, in particular of mechanical pulp, paper or semichemical pulp, and preferably cardboard, a second intermediate layer (24) which is thin compared with the other layers and is composed of a greasetight, water-repellent material, e.g. a polyethylene or coating filmand a third layer which forms the top surface and is composed of absorbent wood pulp tissue (26).
2. Tray in accordance with claim 1, characterised by the fact that up to 50%, and preferably up to 100%, of the bottom layer (20) is made of recycled paper.
3. Tray in accordance with claim 1, characterised by the fact that the top layer (26) and the intermediate layer (24) is a preliminary product in rolled form with a wood pulp tissue layer coated with polyethylene.
4. Tray in accordance with claim 1, characterised by the fact that at least two adjacent layers (e.g. 20, 24) are glued together, in particular by pointwise bonding.
5. Tray in accordance with claim 1, characterised by the fact that at least two adjacent layers (e.g. 24, 26) are bonded to each other by embossing.
6. Tray in accordance with claim 1, characterised by the fact that the intermediate layer (24) is a few micrometres thick, e.g. 6 to 8 micrometres.
7. Tray in accordance with claim 1, characterised by the fact that the intermediate layer is expandable, in particular can be extended by 10% without becoming untight.
8. Tray in accordance with claim 1, characterised by the fact that it is connected with another tray via a fold made of the three-layered material according to the invention to create one piece whereby in one blank two trays are connected to each other via a fold line.
9. Tray in accordance with claim 1, characterised by the fact that the uppermost layer (20) has a water-permeable, perforated, moisture-repellent coating (28) made of plastic, in particular of polyethylene or latex.

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