WO1991000835A1

WO1991000835A1 - Dish for sales packaging of foodstuffs

Info

Publication number: WO1991000835A1
Application number: PCT/DE1990/000132
Authority: WO
Inventors: Reinhold Pietrek
Original assignee: Reinhold Pietrek Gmbh
Priority date: 1989-07-10
Filing date: 1990-02-26
Publication date: 1991-01-24
Also published as: EP0481996A1; EP0481996B1; DE3922644A1; ES2041175T3; ATE87580T1; DE59001138D1; CA2064038A1; JPH05500198A; DK0481996T3

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

Name: Tray for food sales packages

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.

Various trays are known for packaging food, particularly 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 function of the absorbent layer is to absorb and retain moisture originating from the foodstuff, so that, for example, when fresh meat or fruit is packaged, it does not happen that liquid can (visibly) 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.

Disposal is a disadvantage of this known foam tray with cellulose cut as an insert. 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 every single foam shell has a certain volume. Since, moreover, the number of trays to be destroyed 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 not hitherto been satisfactory. In addition to the foam shell, a so-called groundwood shell 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 thickness of the material, that is to say it can soak through, and it then loses its mechanical stability. For hygienic reasons, the wood sanding used must be treated properly in terms of food hygiene, which in practice can only be achieved by using pure wood sanding over the entire thickness. For this reason, the groundwood shell is generally more expensive than the foam shell 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 the coating. Under these circumstances, there is no problem with disposal.

Proceeding from this, the object of the invention is to provide a shell for sales packages which, on the one hand, can be disposed of, in particular burned, without environmental problems, 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 at low cost is.

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 forming the outer surface, in particular wood pulp, paper or semi-pulp and preferably cardboard, one as thin as possible 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 There is fiber material, 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 optimum carrying properties and dimensional stability with the least possible use of material, without taking into account weakening stability in the event of moisture penetration or demands on the the sterility of the material required for food 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 entirely with regard to its blocking effect on fat and water on the one hand and germs on the other hand. The intermediate layer should be stretchable, so that no cracks or perforations occur when the shell is deformed, as occurs in handling, for example during the purchase, when inserted into a sales car, etc. Furthermore, in the case of a stretchable film, the shell can be embossed 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. It is dimensioned sufficiently in its thickness that the amounts 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, napkins and the like. This upper layer is preferably embossed, 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 of 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 on the one 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.

Rails for sales packages of the type in question are basically only suitable for single use. Multiple use stands in the way of the high effort required 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 somewhat thicker for special applications, namely foods to be packaged with a high volume 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. The invention thus opens up 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 embossing. Sufficient cohesion of the three layers is achieved in each case. A sufficient cohesion is a connection of the layers, in which they do not separate independently from one another during normal use of the shell, at most gently diverge at the common edge. This means that, in the shell according to the invention, generally two adjacent layers can 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 point gluing, the amount of glue 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 plug-in connections of 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 invisible, at best only to be recognized by the punched edges (cut edges).

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

Further advantages and features of the invention result 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 - 6 -

3 shows a representation corresponding to FIG. 2 of a second exemplary embodiment

1 shows a shell, known in one piece, from a blank and of known shape, 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 cheapest possible 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 coordination 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 during practical use of the tray according to the invention. Their absorbency is such that the amounts of liquid typically obtained 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 so that environmentally friendly disposal of the entire shell is possible. Although it is fundamentally possible to produce the three-layer web from which the blanks for the shell are made from three individual, separate layers in one operation, it is preferred to first change the intermediate layer, preferably with the upper layer 26, in a modified one (Not shown here) 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 interposed on one side of a web of smooth cellulose tissue as the intermediate layer 24. 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 top 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 which ensure sufficient grease and water tightness can also be used. Basically, an intermediate layer 24 made of wax, a suitable lacquer or the like is possible.

It has proven to be very advantageous to punch out not only one shell but two blanks for shells which are connected in the region of a folding line when cutting. In this way, foldable containers can be produced, 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 fold 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; corrugated cardboard, for example, which offers good thermal insulation due to the high, stored air volume, is suitable here.

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 upper layer, it prevents it from sticking to it or entraining fibers when food is removed therefrom. The absorbency of the upper layer 26 is retained due to the water permeability of the layer 28. The permeability of the support 28 is matched to the respective product to be packaged in such a way that no amount of liquid can accumulate on the support 28. Rather, the product always remains dry on the pad 28. Furthermore, the pad 28 is water-repellent and not swelling itself, and has as little liability as possible to the products to be packaged. This ensures that the product to be packaged does not stick to the support. The support 28 is preferably shaped, 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 the drainage of 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, and the water permeability is brought about by suitable additives in the film which spring open after the casting process.

The openings 30 in the support 28 are so small that they cannot be seen by the eye. The openings 30 can be formed by needle perforation, as capillary openings, as micro-slits, through the molding or the like. A larger education is not excluded. The layers 20, 24, 26 and the support 28 are connected to one another over the entire area.

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

Expectations

1. 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, characterized in that the shell consists of three layers (20, 24 , 26), namely a lower, shaping layer (20) which forms the outer surface and is made of fibrous material, in particular wood pulp, paper or semi-pulp and preferably cardboard, and an intermediate layer (24) of a fat-tight type which is as thin as possible ten, water-repellent material, e.g. B. a polyethylene or Lack¬ layer and an inner surface forming, absorbent, upper layer (26) made of cellulose tissue.

2. Shell according to claim 1, characterized in that the lower layer (20) consists of over 50%, preferably up to 100% of waste paper.

3. Shell according to claim 1, characterized in that the upper layer (26), the intermediate layer (24) is a web-shaped preliminary product made of a cellulose tissue layer coated with a polyethylene layer.

4. Shell according to claim 1, characterized in that at least two adjacent layers (z. B. 20, 24) are glued together, in particular glued by point gluing.

5. Shell according to claim 1, characterized in that at least two adjacent layers (z. B. 24, 26) are interconnected by embossing. 6. Shell according to claim 1, characterized in that the intermediate layer (24) is a few micrometers thick, for. B.

6 to 8 microns thick.

7. Shell according to claim 1, characterized in that the intermediate layer is elastically stretchable, in particular 10% can be stretched without becoming leaky.

8. Shell according to Anspiruch 1, characterized in that it is integrally connected to a further shell via a joint region made of the three-layer material according to the invention, with two shells being connected to each other via a joint region in a one-piece cut.

9. Shell according to claim 1, characterized in that the top layer (20) is covered with a water-permeable, moisture-repellent pad (28) made of plastic, in particular polyethylene or latex.