WO2003031282A1

WO2003031282A1 - Packaging container for receiving foodstuffs and method for producing same

Info

Publication number: WO2003031282A1
Application number: PCT/EP2002/011308
Authority: WO
Inventors: Stephan Halstrick; Joachim Kögler
Original assignee: Linpac Plastics Gmbh
Priority date: 2001-10-10
Filing date: 2002-10-09
Publication date: 2003-04-17
Also published as: EP1434722A1

Abstract

The invention relates to a packaging container for the in particular gas- and/or liquid-tight reception of preferably liquid-exuding foodstuffs, such as meat (10), fish or the like. An open side of a tray can be sealed with a cover (12) in a gas- and/or liquid-tight manner, thus making it possible to manufacture in particular a MAP package. In addition, the walls of the tray (11) are configured as having at least two plies. According to the invention, an open-cell foam plastic inner ply (17) of a circumferential side wall (15) of the tray (11) is reduced at least in its thickness. In this manner, a minimum concentration of the modified gas is maintained in the packaging container over an extended period of time so that perishable foodstuffs can be stored over an extended period of time and still remain fresh.

Description

Packaging container for receiving foodstuffs and method for producing same

Description

The invention relates to a packaging container for the gas- and/or liquid-tight reception of in particular liquid-exuding foodstuffs pursuant to the preamble of Claim 1 , and a method for producing a packaging container pursuant to the generic part of Claim 12.

Packages for liquid-exuding foodstuffs should be capable of absorbing liquids exuded by the foodstuffs during transport and storage, for example blood, meat juices or the like, so that these liquids are not visible from outside the pack, as they present an unappealing sight to consumers and may have a negative influence on the consumer's purchase. Furthermore, packaging containers, particularly those of the aforementioned type, should meet requirements concerning air tightness.

In order to meet the requirements for ensuring an air-tight package as well, packaging containers of the described kind are made in many cases from a tray to form a relatively stabile or rigid bottom part of the packaging container and from a cover made preferably of film, in particular a transparent film, to close the open side of the tray. The tray generally comprises a two-ply foam plastic material. The cover is usually joined to the entire surface of an upper edge of the tray in a gas- or air-tight manner. For receiving the liquid exuding from the foodstuffs there is an inner ply facing the foodstuffs made of a material which can absorb the liquids, such as an open-cell foam plastic material.

To insure that the perishable foodstuffs inside the package remain fresh over a sufficient period of time, the inside of the packaging container has a modified atmosphere. Such packages, are also known under the term MAP (modified atmosphere packaging). During the packaging process, the foodstuffs are first put into the tray, with the ambient air then being evacuated from the tray and replaced by a modified gas such as pure oxygen (0₂) or the like. Finally, the cover is attached to the tray in an air-tight manner. However, one disadvantage of such packages is that even after the tray has been sealed, the modified gas may leak out of the package, above all through the inner ply made of open-cell foam plastic. This reduces the concentration of the modified gas in the package, with the possible result that the foodstuffs in the package will not stay fresh over a sufficient period of time.

The object of the present invention is therefore to affect a further development of known packaging containers of the type named at the outset such that they ensure that perishable foodstuffs remain fresh over a sufficient period of time, and to provide a method for producing a packaging container that ensures sufficient freshness.

A packaging container according to the invention exhibits the features of Claim 1. In that the inner ply of the tray is at least partially profiled and/or has a groove in such a way that the inner ply is reduced at least in its thickness, the escape of the modified gas is at least reduced. Consequently, the modified gas concentration in the packaging container remains constant to a sufficient degree over an extended period of time.

Pursuant to an advantageous further development of the invention, it is provided that the inner ply is interrupted or divided in the region of the profile, preferably in multiple successive stages of the profile. In this manner, the escape of the modified gas through the open-cell foam plastic of the inner ply can be further reduced.

The at least one groove issuing from the inner side of the tray is configured such that it results in a reduction in the thickness of the inner ply to the extent that its cell structure is completely or at least essentially removed. In this manner, the open-cell foam plastic of the inner ply is compacted in the region of the groove so that a barrier is created which prevents a gas from passing through the inner ply which is compacted on the bottom of the respective groove. Alternatively, the inner ply can also be interrupted by the respective groove.

The profile or the at least one groove in the inner ply of open-cell foam plastic prevents modified gas from passing through the inner ply to a collar which runs around the side wall of the tray and which serves to connect the tray to the cover. Therefore, it is possible to retain the original thickness and cell structure of the inner play as well as the outer ply in this region. In the packaging container according to the invention it is therefore not necessary to reduce the thickness of the foam plastic of the inner and outer ply in the region of the collar.

Pursuant to a preferred design of the invention, a collar is provided whose thickness is to be reduced on the whole or at least in part. This results in a compacting of the foam plastic in both plies in the collar region. This compacting is preferably carried out to the extent that the foam structure of both plies is eliminated, i.e. at least to the extent that the collar, at least in part, then only consists of compacted foam plastic, thus making the collar impervious to gas.

Pursuant to a preferred further development of the invention, it is provided that a gas- and/or liquid-tight cover film is arranged on the walls of the packaging container facing the foodstuff. This cover film can cover the inner side of the tray completely or be merely arranged over specific surfaces, for example in the region of the bottom wall. The cover film can preferably be arranged directly on the open- cell foam plastic layer. The cover film is meant to minimize further the escape of the modified gas from the packaging. Furthermore, this creates a smooth, attractive surface in the inner portion of the tray. Inasmuch as the cover film extends into the region of the collar, it also promotes the connection between the collar and the cover. To make sure that liquids exuded by the foodstuffs continue to be absorbed, provisions are made such that at least one bottom wall of the packaging container has a perforation on the side facing the foodstuffs. The perforation admits the liquid through the cover film to the inner liquid-absorbent ply which absorbs the liquid. However, the openings accessible to the modified gas are relatively small so that only a slight amount of modified gas can reach the inner open-cell ply in the first place, whereas, due to the profiled design or isolation of this inner ply or, either alternatively or additionally, at least one groove, the escape of modified gas from the package container can be at least reduced. The perforation can also be arranged in the region of the side walls. Preferably, however, the perforation is arranged in the region of the side wall below the profiled section. If the bottom wall provided with a circumferential groove, which extends expediently into the margin areas of the bottom wall, the perforation is located within the area bounded by this groove. This also ensures that the modified gas entering the open-cell inner ply through the perforation is unable to flow at all, or to no appreciable degree, outwardly to the side walls of the tray due to the barrier effect of the circumferential groove.

Furthermore, a gas- or liquid-tight cover film can be arranged on the walls of the packaging container not facing the foodstuffs. The cover film can be arranged on the entire outer side of the tray, for example.

Further to a preferred further development of the packaging container pursuant to the invention, in the region of its collar the inner, liquid-absorbent foam plastic ply and the outer foam plastic ply are compressed. This compression is preferably carried out to such an extent that the foam structure of both plies is eliminated. Accordingly, the compressed collar region then consists, either completely or in part, of completely compressed plastic in both plies. The fact that compression or compacting of the collar 16 occurs along its perimeter, i.e. uninterrupted in the circumferential direction of the collar, it is therefore impossible for any gas to escape from the tray through the collar, in particular through its outer cut edge.

A method for solving the object stated above exhibits the measures disclosed in Claim 12. Accordingly it is provided that both plies are compressed by ultrasonic means. This type of compression can be executed quite rapidly and completely eliminates the foam structure of both plies, with the result that the collar region compressed or compacted by ultrasonic means is gas-tight. The compression of at least parts of the collar can be done by using ultrasound without any additional application of heat, preferably by exploiting the heat applied to the tray during deep-drawing. In this manner, the compression of at least part of the collar can not only be executed rapidly but also without any adverse effects to the synthetic material.

Further sub-claims relate to advantageous further embodiments of the packaging container and to the method for producing same.

Preferred exemplary embodiments of the invention will be described in more detail in the following as based on the drawing, in which is shown: Fig. 1 perspective view of a cross-section through a packaging container,

Fig. 2 an enlarged section of the view in Fig. 1 in the region of an upper edge of the packaging container, and

Fig. 3 an enlarged section of the view in Fig. 1 in the region of a bottom wall of the packaging container. Fig. 4 a cross-section through a margin area of a packaging container according to a second exemplary embodiment of the invention,

Fig. 5 a third exemplary embodiment of the invention in a view analogous to Fig. 4, and

Fig. 6 a fourth exemplary embodiment of the invention in a view analogous to Fig. 4.

Fig. 7 a fifth exemplary embodiment in a view analogous to Fig. 2.

The packaging containers shown here are employed to receive liquids (such as blood) exuded from foodstuffs. This may involve meat, fish, poultry or the like.

Fig. 1 shows in schematic view a foodstuff portion, namely a piece of meat (10) (for example), which is packed in a gas- and/or air-tight packaging container. The packaging container, however, can also be employed to receive a plurality of meat portions or of other kinds of foodstuffs, even those of different or mixed types. The packaging container has a (lower) tray 11 and cover 12, which closes the complete surface of an upper open side of the tray 11. The entire packaging container, that is to say, the tray 11 as well as the cover 12, is designed to be not only liquid-tight but also gas-tight, in particular air-tight. With the cover 12 connected to the tray 11 , the meat 10 packed in this manner is completely sealed in the packaging container in a liquid- and gas-tight manner.

The cover 12 is made from a gas- and liquid-tight film of preferably plastic. The plastic film used to make the cover 12 is clear or transparent. It thus provides a view into the packaging container and thus the inspection of the meat 10 or^' other foodstuff contained therein. The cover 12 completely spans the entire top open side of the tray.

The tray 11 is designed so that it represents a relatively rigid structure with a depression surrounded on all sides by an edge to form a receiving space 13 for the meat 10 or other foodstuff. The tray 11 has a basic tray member with a preferably square or rectangular, flat base wall 14 and a circumferential side wall 15 projecting obliquely upwards with respect to the base wall 14. However, the tray may also exhibit any number of differently designed base surfaces. The basic tray member of the base wall 14 and the circumferential side wall 15 also has a circumferential collar 16 which adjoins and surrounds the top edge of the side wall 15. The collar 16, which runs approximately parallel to the base wall 14, projects outwardly with respect to the side wall 15. The collar 16 thus runs completely around the top open side of the tray 11.

The full-surface cover 12 in the exemplary embodiment shown lies on the top side of the collar 16 which runs around the tray 11. The transparent plastic film of the cover 12 thereby makes a connection with the tray 11 which is not only liquid-tight but also gas-tight, specifically in the region of the circumferential collar 16. This gas- and liquid-tight connection is brought about in that a margin area of the cover 12 is permanently connected all around the top side of the collar 16. The walls of the tray in the shown exemplary embodiment, side wall 14, collar 16 and bottom wall 14, are configured as being essentially two-plied. A first, inner ply 17, which faces the meat 10 or foodstuff, comprises an open-cell foam plastic, for example a liquid-absorbent polystyrene foam. The ply 17 of the tray 11 thus serves to soak up the liquid exuded by the meat 10, i.e. the meat juices. Located adjacent thereto, namely below the inner ply 17, is a second, outer ply 18 which is turned away from the meat 10 or foodstuff. This outer ply 18 if formed from a closed-cell foam plastic and is essentially gas- and liquid-tight. This ply 18 can be made from recycled plastic. The two plies 17, 18 extend completely across the entire tray 11, i.e. in the region of the bottom wall 14 and side walls 15 as well as in the region of the collar 16. The two plies are permanently joined to one another by means of sealing, plastic-welding, gluing or the like.

The tray 11 is filled in such a way that the meat 10 or another foodstuff is first put into the tray and the tray 11 is then closed with the cover 12. However, prior to the sealing of the tray 11 , the atmosphere of the tray 11 or of the receiving space 13 is exchanged, namely by a modified atmosphere. The modified atmosphere is intended to ensure that the meat 10 or other foodstuff is preserved, in particular that it remains fresh for a relatively long time. Thus the atmosphere in the receiving space 13 is exchanged with a modified gas, for example, or a sufficient quantity of modified gas is delivered until a certain concentration of the modified gas is attained. Appropriate for the modified gas are, for example, O₂ or CO₂ in high concentrations, such as 70 - 75%.

One special feature of the invention is that the side wall 15 of the tray 11 has a profile 19. The profile 19 is configured such that the thickness of the inner ply 17 is at least reduced. Fig. 2 shows the profile 19 on an enlarged scale. The profile 19 ensures that, after the tray 11 has been closed with the cover 12, the modified gas cannot escape from the closed tray 11, or if at all, only to a very slight degree. Some of the modified gas flows through the open-cell foam plastic of the inner ply 17. Said gas flow through the inner ply 17 is stopped at the profile 19, which interrupts the inner ply or which at least reduces its thickness. The profile 19 if preferably configured so that the inner ply 17 of open-cell foam plastic is interrupted or divided. In the shown exemplary embodiment , the inner ply 17 is interrupted a number of times by the profile 19. To this end, the profile is configured in a somewhat stepped or staged form at the inner side of the inner ply 17, whereby at the inner side of the circumferential side wall 15 a likewise circumferential recess is created between each adjacent step of the profile 19. Each of the spaced recesses extends in a different plane, with these planes always running parallel to the bottom wall 14. Located in the region between every two steps of the profile 19 are indentations 20 which divide the inner ply 17. The edges of the respective steps meet at the indentation at an approximately right angle. In the shown exemplary embodiment with an oblique side wall 15 of the tray 11 , each step has a vertical edge and a shorter horizontal edge. An indentation 20 is located between the short horizontal edge of each step and the following longer vertical edge of the next step. Due to the steps and the circumferential recesses created by them, the indentations 20 follow one another at short intervals.

The extent of the profile 19 is limited preferably to an upper region of the side walls 15, namely proceeding from the top edge, in particular the collar 16, of same and ending at still some distance before the transition of the side wall 15 to the bottom wall 14. Accordingly, a lower level of the side wall 15 in the shown exemplary embodiment is free of profiles 19. Preferably the profile 19 extends all around the inner side of the tray 11.

Profiles 19 having a different form are also conceivable, for example with a grooved or "wavy" contour. But as is the case in the shown exemplary embodiment , the main point is that the inner ply 17 of open-cell foam plastic is reduced in its thickness or separated.

The two plies 17 and 18 outside the areas of the profile 19 are essentially unaltered in their thickness, in particular in their cell structure. As a result, each ply 17 and 18 (in itself) in the shown exemplary embodiment has approximately the same thickness in the region of the bottom wall 14, the collar 16 and that part of the side wall 15 which has no profile 19. Among each other, the plies 17 and 18 can have different thickness as well as the same thickness. In the shown exemplary embodiment the outer ply 18 is somewhat thicker than the inner ply 17.

As a further special feature a cover film 21 is provided on the inner side of the tray 11 , i.e. on the walls facing the meat 10. The cover film 21 is gas-tight for the most part and extends preferably across the entire inner side of the tray 11 , thus continuously across the entire region of the profile 19 as well. Accordingly, unlike the inner ply 17, the cover film 21 is not divided in the regions of the indentations 20. In the regions of the indentations 20, the outer ply 18 on the inner side of the tray 11 is therefore at least covered by the cover film 21. To ensure that the liquid exuded by the meat 10 or foodstuff can still reach the inner ply 17 despite the presence of the cover film 21 , the cover film 21 is perforated at least in the region of the bottom wall 14 of the tray 11. The perforation 22 allows the liquid exuded by the meat 10 to reach the inner ply 17 of open-cell foam plastic. The perforation 22 is preferably laid out in a uniform grid pattern. The perforation 22 can also extend in the region of the side walls 15. In this case, however, the perforation 22 ends below the profile 19. In addition, a further cover film 23, which also is made of a largely gas-tight material, is arranged on the outer side of the tray 11 , i.e. on the walls facing away from the meat 10 or foodstuff. The two cover films 21 and 23 contribute to an even smaller reduction in the concentration of modified gas after the tray 11 is closed. If necessary, the cover films 21 and 23 may be omitted.

In a deviation from the shown exemplary embodiment, the tray can have more or less than two plies. What is decisive is that the inner ply 17 is suited to absorb the liquids running out of the meat 10 or foodstuff and that the outer ply 18 is suited for ensuring a gas- and liquid-tight sealing of the tray.

Fig. 4 shows a second exemplary embodiment of the packaging container according to the invention. In its construction and application, the packaging container corresponds to the packaging container described in detail above in conjunction with Figs. 1 to 3. For this reason, the same reference numbers are used to designate the at least functionally identical parts. The cover 12, which is also present in the tray shown here, is not shown in Fig. 4 in order to present a more clear illustration.

Instead of having the profile 19 of the packaging container of Figs. 1 to 3, the packaging container of Fig. 4 has only a groove 24 in the inner ply 17 of liquid- absorbent foam plastic. The groove 24 is assigned to the bottom wall 14 of the tray 11. The groove 24 proceeds from the inner side of the tray 11 , i.e. from the top side of the inner ply 17. The groove runs all the way around the margin area of the bottom wall 14. A perforation is present within the area of the bottom wall 14 enclosed by the groove 24 if the inner side of the ply 17 is provided with a cover film 23. This cover film then extends through the groove 24 as well, although it can interrupted if necessary when the groove is made in the ply 17.

The groove 24 in the shown exemplary embodiment is configured such that the inner ply 17 of open-cell foam material is compressed or pinched. This occurs to such a degree that the foam material of the inner ply 17 loses its open-cell structure and is essentially compacted. The compacted residual material 25 is then located at the base of the groove 24. However, the inner ply 17 can also be completely interrupted by the groove 24.

The inner ply 17 in the shown exemplary embodiment has no profile in the region of the side wall 15. Furthermore, the thickness of the ply 17 in the region of the side wall 15 is smaller than in the region of the bottom wall 14. In addition, the inner ply 17 extends in the shown exemplary embodiment only across a partial region of the collar 16, specifically only across an inner region of the collar 16 which proceeds from the top edge of the side wall 15.

It is conceivable that the groove 24 in the bottom wall 14 according to the exemplary embodiment shown in Fig. 4 can also be provided in addition to the profile 19 in the tray 11 according to Figs. 1 to 3. Fig. 5 shows a third exemplary embodiment of a packaging container according to the invention, which in turn corresponds in principle to the packaging container described in detail in Figs. 1 to 3. Accordingly, the same reference numbers are used to designate at least functionally identical parts.

In the packaging container shown in Fig. 5, the bottom wall is again surrounded by a groove 24. In addition, this packaging container has a second groove 26 in the tray 11. This groove 26 is arranged in the collar 16, specifically in the region of transition of the side wall 15 to collar 16. The groove 26 is located where the collar 16 has only a single-ply configuration, namely where it only has the outer ply 18 but no inner ply 17. Accordingly, the groove 26 extends in the closed-cell foam plastic of the lower ply 18, specifically proceeding from the top side of the collar 16. The groove 26 also extends circumferentially (uninterrupted) in the collar 16. The groove 26 surrounds an edge of the inner ply 17 of liquid-absorbent foam plastic which tapers off in the region of the collar 16. The groove 26 can thereby border the outer encompassing edge of the ply 17 so that during the formation of the groove 26 the encompassing edge of the inner ply 17 is compressed, thus creating a closed-cell film of compacted plastic at the edge of the ply 17 and preventing any modified gas from escaping at this edge.

Finally, Fig. 6 shows a forth exemplary embodiment of the invention. This tray 11 also has basically the same configuration as the tray 11 of the exemplary embodiments described above, so that once again the same reference numbers are used to designate parts which are identical or identical in principle.

Next to the groove 24 at the outer edge of the bottom wall 14 the tray 11 shown here has at the top edge of the side wall 15 a profile which is configured as a stepped groove 27. The groove 27 proceeds from the top side of the collar 16 and from the inner side of the side wall 15. The groove 27 forms a top seal of the inner ply 17, which thereby ends at the edge of the side wall 15 slightly below the collar 16. The groove 27 extends from the inner, liquid-absorbent ply 17 into the closed- cell ply 18 in the direction of the outer circumference of the collar 16. The groove 27 serves in turn to form a tight seal of the top edge of the inner ply 17 lying below the groove 27. By virtue of having such a closed edge of the inner ply 17 of open- cell foam plastic, no modified gas, or only a very slight amount of modified gas, can escape past the edge of the inner ply 17.

Furthermore, the collar 16 of the tray 11 shown in Fig. 6 has two grooves 28 and 29. The grooves 28 and 29 are made in the collar 16 from below by reducing the thickness of the outer ply 18 of closed-cell foam plastic, which alone forms the collar 16. An inner groove 28 immediately borders the top edge of the side wall 15, thus surrounding it on the outside. The groove 28 is made at the outer edge of the collar 16 at a distance from this inner groove 28. In this manner the circumferential outer groove 29 surrounds the likewise circumferential inner groove 28 at a parallel distance. Located between the grooves 28 and 29 is a residual section 30 of closed-cell foam plastic of the outer ply 18. The outer ply 18 can be reduced somewhat in the region of this residual section 30; but it can also, in contrast to the shown exemplary embodiment, have the same thickness in the region of the residual section 30 as it does in the region of the side wall 15 and/or bottom wall 14.

By putting the grooves 28 and 29 into the collar 16 from below, the top side of the collar 16 remains smooth for the application of a cover film 12, which is not shown in Fig. 6. The collar 16 in the shown exemplary embodiment merely has regions extending across the grooves 28 and 29 in which the outer ply 18 is compressed, so that the cell structure is essentially lacking, whereas in the residual section 30 the outer ply 18 is reduced in thickness only slightly as required so that here the cell structure remains preserved at least in part.

Fig. 7 shows a further exemplary embodiment of the invention, specifically a modification of Fig. 1 and 2 of the shown tray 11. The same reference numbers are used for the same parts.

Tray 11 in Fig. 7 differs from that shown in Fig. 1 to 2 in the configuration of the collar 16. Here the inner ply 17 as well as the outer ply 18 are compressed in an outer region 31 of the collar 16 and are thus reduced in thickness. The reduction in thickness proceeds from a bottom side of the collar 16 so that by virtue of compression a top side 32 of the collar 16 is non-stepped, i.e. it runs completely in a horizontal plane. This makes the entire surface area of the collar 16 available connecting the cover 12 to the collar 16 of the tray 11. Only a collar region proceeding from a circumferential outer edge 33 of the collar 16 is compressed. In the shown exemplary embodiment approximately somewhat more than half the collar 16 is compressed. However, a larger or smaller region of the collar 16 can also be compressed, for example as shown by the exemplary embodiment in Fig. 6.

The compression of the inner ply 17 and the outer ply 18 in the outer region of the collar is carried out to the extent that the foam structure of the inner ply 17 as well as of the outer ply 18 is eliminated for the most part, preferably completely. The compressed outer region of the collar 16 then consists completely of compacted plastic, specifically that formed by the inner ply 17 and outer ply 18. Both plies 17 and 18 are internally fused during compression so that the compacted outer region of the collar 16 in effect consists of a single, preferably homogenous layer of compact plastic.

The compression of the collar 16 according to the invention is done by ultrasound. This can occur during the deep-drawing of the tray 11 , or immediately following the deep-drawing process. After the collar 16 is compressed, its outer contour is punched out, i.e. the deep-drawn blank for forming the tray 11 is trimmed along the perimeter of the collar 16, thus forming the circumferential edge 31. If necessary, compression of the collar 16 can also be executed before it is deep- drawn.

The tray 11 is not heated when the collar 16 is compacted with ultrasound. Instead, for compression during deep-drawing or immediately thereafter, the residual heat still present in the tray 11 from the deep-drawing process is utilized for ultrasound treatment. Compression of at least one part of the collar 16 using ultrasound is carried out between a displaceable stamp (anvil) and a stationary plate. The stationary plate is energized by ultrasound. The stationary, level plate preferably lies on the top side 32 of the collar 16, with the plate extending completely across the entire top side 32 even if only part of the collar 16 is compressed using ultrasound. The displaceable stamp is pressed against the underside of the collar 16, acting toward the stationary plate at the top side 32 of the collar 16 until the foam structure of the inner ply 17 as well as of the outer ply 18 is preferably completely eliminated. In the process, the distance between the displaceable stamp and the stationary, ultrasonic-energized plate is continually decreased to the point where only a narrow gap remains, which is filled out by the compressed, or compacted, plastic of both plies 17 and 18.

Ultrasound can also be used to form the grooves 28 and 29 in the collar 16 of the tray 11 according to the exemplary embodiment in Fig. 6. The remaining grooves 24, 26 and 27 can also be formed by ultrasound. Finally, it is also conceivable to form the inner profile of the side wall 15 of the tray 11 by utilizing ultrasound.

Other exemplary embodiments of the tray according to the invention are conceivable, in which the profile 19 and the grooves 24, 26, 27, 28 and/or 29 can be combined arbitrarily.

List of designations

10 meat

11 tray

12 cover

13 receiving space

14 bottom wall

15 side wall

16 collar

17 ply

18 ply

19 profile

20 indentation

21 cover film

22 perforation

23 cover film

24 groove

25 residual material

26 groove

27 groove

28 groove

29 groove

30 residual section

31 outer edge region

32 top side

33 edge

Claims

Patent claims

1. Packaging container for the in particular gas- and/or liquid-tight reception of preferably liquid-exuding foodstuffs, such as meat (10), fish or the like, with a tray (11 ) exhibiting an open side and having an inner ply (17) of liquid-absorbent, open-cell foam plastic and an outer ply (18) of a closed-cell foam plastic, and with a cover (12) for the gas- and/or liquid-tight sealing of the open side of the tray (11 ), characterized in that the tray (11 ) has a profile and/or at least a groove (24, 26, 27, 28, 29) in such a manner that the inner ply (17) is at least reduced in its thickness.

2. Packaging container according to Claim 1 , characterized in that, as a result of the profile (19), the inner ply (17) is interrupted or divided at least once, preferably several times.

3. Packaging container according to Claim 1 or 2, characterized in that the profile (19) and/or the at least one groove (24, 26, 27, 28, 29) is arranged in an upright or oblique side wall of the tray (11 ) and/or in a preferably flat bottom wall of the tray (11 ).

4. Packaging container according to one of the previous claims, characterized in that in the region of the or each groove (24, 26, 27, 28, 29) the inner ply (17) is reduced in thickness to the point where the cell structure of the foam plastic is essentially and preferably completely removed.

5. Packaging container according to one of the previous claims, characterized in that the open side of the tray (11) is surrounded by a circumferential collar (16) and that the cover (12) in the region of the collar (16) can be joined to the tray (11) with a gas- and/or liquid-tight seal.

6. Packaging container according to one of the previous claims, characterized in that in the region of the circumferential collar (16) the inner ply (17) as well as the outer ply (18) are essentially uninterrupted.

7. Packaging container according to one of the previous claims, characterized in that the inner ply (17) and the outer ply (18) are compressed in the region of the circumferential collar (16), in particular such that both plies (17, 18) exhibit essentially no foam structure.

8. Packaging container according to one of the previous claims, characterized in that a gas- and/or liquid-tight cover film (23) is arranged on the side of the inner ply (17) facing the foodstuffs.

9. Packaging container according to one of the previous claims, characterized in that the cover film (23) also extends across the region of the profile (19) and/or at least one groove (24, 26, 27, 28, 29) and, preferably at least in the region of the profile (19), runs continually, in particular uninterrupted.

10. Packaging container according to one of the previous claims, characterized in that at least one bottom wall (14) of the tray (11) has on the inner side facing the foodstuffs a perforation (22) which extends continuously through the cover film (23), the perforation (22) extending within the area of the bottom wall (14) bounded by the circumferential groove (24).

11. Packaging container according to one of the previous claims, characterized in that at least several plies of the walls of the tray (11), preferably the inner ply (17), in particular the open-cell foam material layer, and the outer ply (18), in particular the closed-cell foam material layer, are joined to one another along their entire surface, in particular by means of sealing, laminating, plastic-welding and/or adhesive bonding.

12. Method for producing a packaging container having a tray (11 ), with a blank comprising two plies (17, 18) of foam plastic connected to one another and the tray (11 ) being produced from this blank, in particular by deep-drawing, characterized in that both plies (17, 18) are compressed in the region of a collar (16) running around an upper opening of the tray (11) by means of ultrasound.

13. Method according to Claim 12, characterized in that the compression of the plies (17, 18) occurs in the region of the collar (16) during or subsequent to the deep-drawing of the tray (11).