Technical field:

The present invention relates to a packaging container and a method for the production of the same. The packaging container according to the invention is particularly suitable for storing food and it is of such a type that advantageously can be put directly on a breakfast-table or the like.

Prior art:

Packaging containers for food such as butter and the like and which can be placed on a table ready laid are known earlier and they are shaped differently. They all have a cover by which they can be closed. A common feature with packaging containers of said kind is that they are all made of more than one material. They consist of a stiffer outer material which can be pasteboard, paper, thick plastics or the like and an inner somewhat thinner but air and water impermeable material for example a suitable type of a plastic foil. These materials which separately contribute to the good function of the packaging container are joined to each other in different ways. The most common way is however that they are welded to each other either at the edges or over the whole surface or they can be joined by glueing or the like. The packaging container will therethrough get an even appearance and its function will be troublefree.

Technical problem:

One problem with the above mentioned packaging containers which has grown continuously stronger during recent years

is that they consist of two or more materials. This is not a problem per se of the packaging container itself, but it contains a great hindrance when the packaging container has been used and one intends to recover materials from which it has been made. Due to the good joint between the different materials it is very difficult to separate these materials in a simple way. This is however necessary if the materials shall be recovered. One cannot melt plastics together with cellulosic fibres and recover either plastics or the cellulosic fibres in the paper material and these parts or different kinds of plastic materials have to be separated before recovering using known techniques can be started.

The invention:

To make recovering of different materials possible which are part of the packaging containers, one has according to the invention solved the problem with the above said articles and brought about a packaging container consisting of layers of two or more like or different materials such as plastics and cardboard and which is characterized in that the layers are kept together substantially by means of mechanical attachment with each other and can be separated without using a tool.

It is according to the invention advantageous if the mechanical attachment comprises wartlike protrusions in one of the parts which are pressed into holes in the second part. These protrusions can suitably extend out through the holes in the other part and form skulls on the outer side thereof.

It is further according to the invention suitable that the mechanical attachment comprises overhangs at the upper part of the inner part forming a groove in which the upper part

of the outer part fits. Both these measures can be combined.

It is advantageous that the overhang with a groove is arranged at each corner of the packaging container if it has four corners and that the wartlike protrusions are arranged in one or more horizontal rows.

The outer part of the packaging container according to the invention can suitably comprise two or more overlapping materials which are kept together substantially by means of the wartlike protrusions and grooves.

The invention also comprises a method for the production of a packaging container according to the above, which is characterized in that the outer part for example in the shape of a punched carton blank is placed in a mould whereupon the inner part for example in the shape of a plastic blank is applied through vacuum forming, thermo forming, pressure forming or extrusion.

The inner part can suitably be shaped over the edge of the outer part.

According to a modification of the method the inner part can first be preformed and thereafter joined with the outer part through snapping.

Detailed description of the invention: The invention will in the following be described more in detail with connection to the drawings where

Fig. 1 shows a perspective view of a packaging container according to the invention, where

Fig. 2 shows a section according to the line A-A in Fig. 1, where

Fig. 3 shows a section according to the line B-B in Fig. 1, and where

Fig. 4 shows a section through the wall in the packaging container according to another embodiment of the invention.

Fig. 1 shows a packaging container for food having an outer part 1 and an inner part 2. The outer part 1 consists in the present embodiment of paste board which has been punched out and folded in a mould. In this paste board blank holes 3 have been punched out. In the inner part 2 one has instead arranged wartlike protrusions 4 which fit in the holes 3 and which are arranged directly opposite these and finally have been pressed into the holes 3. The holes 3 and the protrusions 4 are suitably arranged in horizontal rows. On the figure one row is shown, but even a plurality of such rows can be arranged.

At the four corners of the packaging container an overhang 5 has been arranged in the inner part of the plastic box. In these overhangs grooves have been made in which the outer part fits. This is further described in connection with Fig. 3.

Fig. 2 which is a section along the line A-A in Fig. 1 shows the inner part 2 of the packaging container and the outer part 1. As appears from the figure wartlike protrusions 4 are made in the inner part 2 which have been pressed into the holes 3 in the outer stiffer part. In this way the inner part is locked with the outer part so that no movement upwardly or downwardly can occur of one or the other part in relation to the other one. The protrusions 4

according to the figure have been made somewhat deeper than the holes so that they protrude outside the outer surface of the outer wall 1 and form skulls outside the surface. The bottom of the protrusions can however be flush with the outer wall of the outer part 1.

Fig. 3 which is a section along the line B-B in Fig. 1 shows that the inner part 2 has been made with an overhang which forms a groove 7 in the inner part 2. In this groove 7 the outer part 1 fits. This overhang 6 is close to the upper part of the inner part 2 and one has therefore made a recess in the outer part 1 so that it shall fit in the groove 7.

At another embodiment of the invention according to Fig. 4 the outer part has been made in two materials of the same kind which overlap each other. They are kept together by the wartlike protrusions 4 with or without skulls and of the grooves 7 in the inner part. The holes 3 can be equal or the inner one can be made somewhat larger than the outer one.

By locking the inner part 2 mechanically to the outer part 1 by means of the protrusions 4 and the overhang 6 with grooves 7 one has obtained a very stable arrangement, but which nevertheless is easy to separate. When the packaging container has been emptied one can easily separate the two parts without using any tool and put them into different compartments when sorting out. Herethrough one gains of course great environmental advantages as the two parts in their entirety can be recovered by known methods.

If one so wishes one may strengthen the attachment by means of a suitable adhesive at some place, but one has then to observe that the adhesive completely at the separation will

remain on only one of the parts where it does not make any pollution.

The packaging container according to the present invention can be manufactured by first punching out a carton blank which shall be the outer part 1 of the packaging container and place this in a mould. In the mould one can thereafter by means of known techniques apply a plastic foil which will be the inner part 2 and either press this one or suck it in by means of vacuum forming, thermoforming, pressure forming or extrusion.

Another way of producing the packaging container according to the invention is that one first makes the inner part 2 and then snaps this on the folded outerpart 1.

The invention is not limited to the embodiment shown and it can be modified in different ways within the scope of the claims. The materials in the packaging container does accordingly not have to be different, but they can be made of the same material which one nevertheless wants to separate after use. One of the materials may for example be provided with printing colours and should therefore not be mixed with the other.