High barrier multipack package comprising plurality of low barrier individual packages

Abstract

A heat sterilizable packaging system (10) comprises an outer composite package (12) enclosing an outer packaging space (14) in which at least two inner individual packages (16) are housed. The multipack (12) is formed from a first packaging layer material (18) comprising at least one polymer layer (44, 48, 52, 54, 56). The individual packaging (16) is formed from a second packaging material (60) which is different from the first packaging layer material, one of the first and second packaging materials (18, 60) as a high barrier packaging material having an oxygen transmission of less than 0.5 cm3 / (m2. D.bar) and a water vapor transmission of less than 0.5 g / (m2. D), and wherein the respective other packaging material (18, 60) has an oxygen transmission of less than 0.5 cm3 / (m2. D.bar) and a water vapor transmission of less than 0.5 g / (m2. D). 60) has an oxygen transmission of greater than 3 cm3 / (m2. D. Bar) and a water vapor transmission of greater than 2 g / (m2. D) as a low barrier packaging material. According to the invention, the first packaging material (18) has at least two polymer layers (44, 48, 52, 54, 56) and is a high barrier packaging material, and the second packaging material (60) is a packaging layer material (60) having at least one polymer layer (62, 64, 66, 68) and is a low barrier packaging material.

Description

Technical Field

[0001] A heat-sterilizable packaging system includes an outer combined package that encloses an outer packaging space in which at least two inner individual packages are accommodated. Each individual package encloses an inner packaging space and is configured for packaging a product. The combined package is formed of a first packaging material that includes at least one polymer layer as a packaging layer material, and the individual packages are formed of a second packaging material different from the first packaging material. One of the first packaging material and the second packaging material is a high-barrier packaging material having an oxygen transmission rate of less than 0.5 cm3 / (m 2 ·d·bar) determined at 23 °C and 85% relative humidity according to DIN 53380-3 and a water vapor transmission rate of less than 0.5 g / (m 2 ·d) determined at 23 °C and 85% relative humidity according to ISO 15106-2, and the respective other one of the first packaging material and the second packaging material is a low-barrier packaging material having an oxygen transmission rate of greater than 3, preferably greater than 5 cm3 / (m 2 ·d·bar) determined at 23 °C and 85% relative humidity according to DIN 53380-3 and a water vapor transmission rate of greater than 2 g / (m 2 ·d) determined at 23 °C and 85% relative humidity according to ISO 15106-2. Background Art

[0002] The starting point of the present invention is an enclosed film packaging as a combined package that assembles a plurality of metal cans, such as tinplate cans, as individual packages into a bundle. Such metal cans of the prior art are the above-mentioned high-barrier packaging materials and have high-barrier properties against the penetration of water vapor and oxygen. Therefore, the metal cans are suitable for packaging foods, especially canned foods, with long durability.

[0003] Since the metal cans already have high-barrier properties as the second packaging material, the first packaging material does not require special barrier properties and can be configured as a cost-effective thermoplastic enclosed polymer film as a low-barrier packaging material.

[0004] The packaging system of the present invention should preferably also relate to foods and especially canned foods as products packaged into individual packages, such as cans in an enclosed film, although in principle products packaged into individual packages different from canned foods or different from foods should not be excluded at all.

[0005] Another advantage of the metal cans mentioned, apart from their very good barrier properties in terms of their numerically low oxygen and water vapor transmission rates, is their outstanding heat sterilizability. The metal cans withstand without problems high temperatures above 120 °C such as those achieved during the sterilization of food packaging, for example during the sterilization of distillation tubes by means of hot steam as is common in the professional field.

[0006] However, a disadvantage of metal cans is their relatively high self-weight. As the portion to be packaged becomes smaller and smaller, the share of this self-weight in the total weight of the package with the packaged article also becomes larger and larger. Since the packaged article always has to be transported at least from the producer to the point of sale, the high tare value causes a deterioration of the CO2 transport balance of the packaged article. Since the transport capacity is usually limited by weight, making full use of the transport capacity in the case of a high packaging weight share means an unfavorably low utilization of the transport capacity with respect to the product being transported.

[0007] In addition, it is relatively costly to permanently attach consumer information about the origin, contents, weight, shelf life, etc. to the outside of the metal can.

[0008] Therefore, the object of the present invention is to improve a heat-sterilizable packaging system of the type mentioned at the beginning, while additionally having good barrier properties against the migration of oxygen and water vapor (moisture), such that, with the same total weight composed of the packaging weight and the packaged article, the share of the packaging weight in the total weight is smaller. Then, with a preset transport weight, a larger weight share of the product can be transported. As a result, the CO2 footprint of the product with respect to the weight of the packaged product decreases.

[0009] In the prior art, there are also known film packaging systems with a packaging bag as a combined packaging and with individual packages accommodated therein, for example for confectionery having a reduced size compared to its normal retail form, such as so-called "Minis". The individual confectionery items themselves are usually packaged in a flow pack made of a packaging film as a second packaging layer material. A number of the packaged confectionery items are wrapped in the packaging bag or in another flow pack made of packaging film. The packaging of the individual confectionery items is usually opaque, while the combined packaging as the wrapper is at least partially transparent. However, this packaging system does not have any special barrier properties with respect to the migration of oxygen and water vapor through the packaging material. If anything, the individual packages that can be removed from the combined packaging may have metallized sections which, apart from an aesthetic effect, also provide a barrier function.

[0010] However, the packaging film for single packaging mentioned above is not suitable for heat sterilization. Heat sterilization, such as the sterilization of the distillation tube mentioned above, is carried out under the condition of using hot steam, in which the package together with its packaged product must withstand a temperature exceeding 120 °C for a long time without changing its structure, shape and function. As long as the single packaging of the above-mentioned film packaging system generally has special barrier properties due to the packaging material layer composed of known barrier materials, the barrier properties are greatly reduced or even eliminated by heat sterilization. As long as the barrier properties are based on the metallization of the polymer layer, for example, the barrier properties are damaged by the increase in temperature because the usually axially oriented carrier layer of the metallization shrinks during a significant temperature increase and forces it and the metallization carried by it to shrink and deform. As long as the barrier properties are based on ethylene alcohol polymers such as EVOH or PVOH, the moisture-sensitive material is endangered by the moisture input by the hot steam to its integrity. Summary of the Invention

[0011] According to the present invention, the object on which the present invention is based is achieved by a packaging system of the type mentioned at the beginning, wherein the first packaging material has at least two polymer layers and is a high-barrier packaging material, and wherein the second packaging material is a packaging layer material having at least one polymer layer and is a low-barrier packaging material.

[0012] The packaging system according to the present invention uses a packaging layer material having one or more polymer layers not only for combined packaging but also for single packaging. The self-weight of at least the single packaging is significantly reduced compared to a known metal can in the case of the same weight of the packaged product per single packaging. Therefore, the weight share of the packaging in the total weight of the packaged product is also reduced in a desired manner.

[0013] Preferably, the first packaging layer material includes at least three polymer layers. Among them, one polymer layer is preferably a sealable inner layer, another polymer layer is a carrier polymer layer, the carrier polymer layer carries a barrier layer preferably composed of metal or metallization or metal oxide, and the polymer layers form an outer layer exposed outward. The barrier effect can be caused by an ethylene alcohol polymer layer alternatively or additionally for the mentioned metallization or metal oxide layer. The number of polymer layers can be further increased by an adhesion or extrusion-bonding promoting layer.

[0014] Equally preferably, the second packaging layer material can include two or more polymer layers. Again, one polymer layer is preferably a sealable inner layer and another polymer layer is an outer layer. An ethylene alcohol polymer layer can be provided therebetween as at least a temporary oxygen barrier layer. Here, the number of polymer layers can also be further increased by an adhesion or extrusion-bonding promoting layer.

[0015] For weight-saving reasons, at least one polymer layer of the first packaging layer material and / or the second packaging layer material may comprise a foamed polymer.

[0016] Here, it is advantageously feasible that the individual package made of the second packaging layer material is designed not only cost-effectively but also thermally sterilizable, since the second packaging layer material can be robustly configured with respect to the thermal load during sterilization, especially during the sterilization of distillation tubes, as a low-barrier packaging material. The second packaging layer material does not require improved barrier properties with respect to the migration of oxygen and water vapor through the second packaging layer material, which is usually achieved only by selecting a load-sensitive material with a usually load-sensitive layer thickness. Thus, each individual package can be thermally sterilized without fear of loss of function, shape or structure of the individual package or its packaging material.

[0017] The currently apparent disadvantage of the lack of an improved barrier to the migration of oxygen and water vapor in the individual package can be compensated for by a co-packaging, which precisely has such barrier properties. For this purpose, the co-packaging is formed from the first packaging layer material, which is a high-barrier packaging material.

[0018] Oxygen at the perishable product can cause its oxidation. Water vapor at the product, i.e., moisture, promotes its complete softening. If the product reached by the moisture contains salt and is thus to some extent hygroscopic, the complete softening occurs to a greater extent.

[0019] Thus, the co-packaging, which can be particularly well perceived by the customer as the outer packaging of the currently discussed packaging system, can be formed with a high-barrier packaging material. Its sensitivity to increased temperature is not loaded, since the co-packaging does not have to withstand an increase in temperature. For this reason, the co-packaging can additionally be provided with consumer information, which can be seen on the outer side presented at the point of sale. It is also completely unproblematic to apply a printing pigment coating to the packaging layer material, even if the packaging layer material, as a high-barrier packaging material, comprises layers with a particularly low oxygen and / or water vapor transmission rate, where "black" is also understood as a printing pigment in this context.

[0020] Generally, the co-packaging has the required barrier properties but is not thermally sterilizable, while the individual package is thermally sterilizable but does not have barrier properties. However, the packaging system for packaging around the product packaged in the individual package overall provides not only the required barrier properties but also the required thermal sterilizability.

[0021] The packaged product may be any product, but preferably a food, particularly preferably a canned food, such as prepared vegetables, prepared meat, etc. The product may be a pourable product or a block product. The term "individual package" merely indicates that the package referred to in this way can be separated from a plurality of individual packages and removed from a multipack. The term does not mean that only a single product is to be packaged by means of an individual package, for example in the sense of a single piece.

[0022] An individual package is considered heat sterilizable in the sense of the present application if it is subjected to a temperature of at least 120° C., but not more than 131° C., for at least 10 minutes, preferably 120 minutes, without changing its size or its functionality or the structure of its packaging layer material.

[0023] The packaging system described here serves to package a plurality of parts, so that after opening the multipack, not all of the individual packages packed therein are usually consumed. In order to be able to place the remaining individual packages again in the barrier protection of the multipack after opening the multipack, the multipack can have a closing device for closing the removal opening again. By visually recognizable tear lines or cut lines, by a pre-defined weakening in the packaging layer material for guiding the once introduced crack or by other measures, the removal opening is already visible as the desired opening position on the multipack in the closed state after filling on the manufacturer's side.

[0024] As already indicated at the outset, the permeability of the packaging layer material with respect to oxygen and water vapor is currently specified as transfer rate. In the professional field, the abbreviation "OTR" for the English term "Oxygen Transfer Rate" is used to represent the oxygen transfer rate, and the abbreviation "WVTR" for the English term "Water Vapour Transfer Rate" is used to represent the water vapor transfer rate.

[0025] According to a first preferred embodiment of the invention, the closure device can include a form-fit device, which is known in the technical field under the term "zipper". This is a form-fit device with a closure strip on each side of the withdrawal opening, which extends along the withdrawal opening. In order to effectively close the withdrawal opening again, the closure strip preferably extends over the entire length of the withdrawal opening.

[0026] One of the closure strips has a positive form-fitting structure extending along the removal opening in the longitudinal direction of said one closure strip. The corresponding other closure strip in the closure strips has a negative form-fitting structure extending along the removal opening in the longitudinal direction of the corresponding other closure strip. The negative form-fitting structure is configured to form-fittingly receive the positive form-fitting structure. In order to at least partially compensate for the weak point formed by the removal opening in the barrier properties of the co-packaging, preferably, each closure strip in the closure strips is at least partially formed of an ethylene alcohol polymer. Considered as ethylene alcohol polymers are ethylene-vinyl alcohol copolymers (EVOH) and polyvinyl alcohol (POVH), both of which advantageously have a low oxygen transfer rate.

[0027] In order to impart to at least one closure strip, preferably two closure strips, in the closure strips an increased mechanical stability compared to a configuration in which they consist only of an ethylene alcohol polymer or / and in order to impart to at least one closure strip, preferably two closure strips, in the two closure strips, in addition to a low oxygen transfer rate, also an as low as possible water vapor transfer rate, at least one closure strip in the closure strips can have a core strip extending in the range of at least 70% of its longitudinal dimension and composed of a polymer material different from the ethylene alcohol polymer. Preferably, the core strip extends in the range of 90% of the longitudinal dimension of the closure strip, particularly preferably in the range of 100% of the longitudinal dimension of the closure strip. Particularly preferably, the two closure strips are first manufactured as approximately endless wire extrusion profiles and segmented into the required lengths. The core strip can carry a barrier structure composed of an ethylene alcohol polymer in sections at least in the range of at least 90% of its longitudinal dimension, particularly preferably 100% of its longitudinal dimension. Other sections of the core strip can be free of ethylene alcohol polymer. Preferably, the two closure strips are configured in the manner and method mentioned.

[0028] The material of the core strip is preferably a thermoplastic polymer. Preferably, the material is polyamide. The material can however also include or be a polyester, such as polyethylene terephthalate. Polyamide shows a higher water vapor barrier, i.e., a lower water vapor transfer rate, compared to, for example, polyethylene or polypropylene, with the same layer thickness of the test material arc. Thus, in a combination composed of polyamide and an ethylene alcohol polymer, a closure strip with a generally good barrier effect against the migration of oxygen and water vapor through the closure strip can be provided with a small strip volume.

[0029] If each closure strip is constructed according to the above description and has a core strip, then in order to obtain a high barrier effect it is preferably provided that, in the closed state of the form-fitting device, when the male form-fitting structure and the female form-fitting structure are in form-fitting engagement with one another, the barrier structures of the two closure strips are in contact with one another in the range of at least 80%, preferably at least 95%, of the engagement length of the form-fitting structures with one another.

[0030] In the circumferential direction around the closure strip, the barrier structure at least partially surrounds the core strip such that the core strip can be sectionally exposed. Preferably, the exposed sections of the core strip form the form-fitting structure. However, it should not be excluded that the barrier structure completely surrounds the core strip in a circumferential manner. Then, the form-fitting structure is also formed from the material of the barrier structure.

[0031] Preferably, at least one form-fitting structure, particularly preferably two form-fitting structures, of the closure strips involved are formed from a polymer different from the ethylene alcohol polymer, namely in particular from polyamide or polyethylene terephthalate, in order to impart increased stability and increased strength to the form-fitting structure and thus to the form-fitting engagement formed therebetween. Thus, two form-fitting structures (one of which forms a projection in a cross-section perpendicular to the longitudinal extension direction of the closure strip, which projection engages into a recess of the respective other form-fitting structure) can form a continuous water vapor barrier across the access opening by means of a labyrinth seal formed between the projection and the recess.

[0032] In addition to the form-fitting structure, the barrier structure can be composed of an ethylene alcohol polymer having corresponding dimensions such that it is in contact in the closed state of the closure device and also forms an oxygen barrier across the access opening that is as little disturbed as possible.

[0033] In a common manner, the form-fitting engagement between the form-fitting devices of the closure strip can be manually established by the respective user in such a way that the user locally establishes form-fitting at the end of the access opening and, in addition, manually applies pressure to the form-fitting devices that are superposed on one another and the fingers applying the pressure can slide along the closure strip towards the other longitudinal end of the access opening.

[0034] In order to facilitate the establishment of the form-fitting engagement, the form-fitting device can include a slider displaceable along the closure strip as an operating aid for operating the form-fitting device. Such a closure device including a "zipper" with a slider is also known in the art as a "Slider".

[0035] The slider preferably surrounds the closure strip and, when moving in the direction of the longitudinal dimension of the closure strip, at least supports the establishment of a form-fit engagement between a male form-fit structure and a female form-fit structure, or is fully responsible for the establishment of the form-fit engagement. When moving in the opposite direction, the slider at least supports the release of the form-fit engagement between the male form-fit structure and the female form-fit structure or completely causes said release.

[0036] Additionally or alternatively to the design variants mentioned above as "zipper" or "slider", the closure device can have an adhesive zone with a cold adhesive in order to obtain a reclosure that is as sealed as possible. The cold adhesive is preferably a pressure-sensitive adhesive known per se, which adheres to each surface section of the assembled package by means of its free adhesive surface. Preferably, the cold adhesive is thus arranged on the surface of the package wall section of the assembled package for adhesion to another package wall section of the assembled package. Preferably, the adhesive zone forms an adhesive strip that extends over at least 75%, preferably at least 90%, particularly preferably 100% or more of the longitudinal dimension of the access opening, so that a reclosability of the access opening over as large a range as possible, preferably complete reclosability, can be achieved.

[0037] Preferably, the assembled package is designed as an assembled packaging bag, since bag packaging can generally have a packaging space with respect to its own weight. As an assembled packaging bag, the assembled package has a front packaging wall and a rear packaging wall. This should not exclude that the assembled package also has side walls, although side walls are not necessarily required. For example, the assembled packaging bag can be designed as a three- or four-edge-sealed bag or as a flow pack. In the case of the last-mentioned flow pack, the rear packaging wall has a longitudinal seal seam.

[0038] Irrespective of the specific structural design of the assembled packaging bag, the outer packaging space is located between the front packaging wall and the rear packaging wall. Then, according to a preferred embodiment, the cold adhesive zone can be arranged on the assembled packaging bag as follows:

[0039] i.) On the inner side of one of the front packaging wall and the rear packaging wall facing the respective other packaging wall or facing the outer packaging space, for adhesive connection to the inner side of the respective other packaging wall, or / and

[0040] ii.) On the outer side of one of the front packaging wall and the rear packaging wall remote from the respective other packaging wall or remote from the outer packaging space, for adhesive connection to the outer side of the respective other packaging wall.

[0041] Option i.) can be simply achieved by adhesively connecting the inner sides of the front packaging wall and the rear packaging wall facing each other to reclose the access opening. The reclosure thus formed is detachable and can be reopened and closed again arbitrarily frequently.

[0042] Option ii.) that can be proposed additionally or alternatively to option i.) can cause the combined packaging bag to roll up beyond the take-out opening from the end region of the take-out opening of the carrier, so that it is shielded from the external surrounding environment in the material roll, for example in the form of a labyrinth seal. In order to fix the material roll relative to the inevitable material-elastic-driven unfolding or partial opening of the packaging material again, an adhesive connection of the outer side of the front or rear packaging wall to the outer side of the corresponding other packaging wall in the front packaging wall and the rear packaging wall is achieved here by means of a cold adhesive zone.

[0043] In order to be able to at least roughly remove the unwanted oxygen fraction from the external packaging space after removing an individual single package from the combined packaging and after re-closing, according to a preferred improvement of the present invention, a valve can be provided in the wall section of the combined packaging, through which gas can flow from the external packaging space to the external surrounding environment of the combined packaging, but cannot flow in the opposite direction. Then, after re-closing the combined packaging, the air entering the external packaging space can be pressed out by the valve acting only in one direction, i.e., from the external packaging space to the outside. As the air escapes from the external packaging space through the valve, the moisture contained in the air also escapes.

[0044] Additionally or alternatively, the combined packaging can have at least one absorbent of an oxygen absorbent and a moisture absorbent in order to keep the content of oxygen and moisture in the external packaging space as low as possible. In principle, oxygen absorbents and moisture absorbents are known in packaging technology.

[0045] In a simple design, the oxygen absorbent or / and the moisture absorbent can be placed in the external packaging space in its own absorbent package, as is known for silica gel pads as desiccants. In order to have to sacrifice as small a volume of the external packaging space as possible to accommodate the absorbent, according to a preferred embodiment, at least one absorbent of the oxygen absorbent and the moisture absorbent can be pressure-activably combined in a polymer layer exposed towards the external packaging space. Preferably, both absorbents are pressure-activably combined in the manner and method mentioned. For example, the absorbent can be accommodated in the exposed polymer layer in the form of microcapsules that are fragile under a predetermined pressure load. By, for example, sweeping across the area doped with microcapsules with the back of a knife or a fingernail, the rupture strength of the microcapsules can be locally exceeded by the pressure generated, thereby releasing and activating the initially encapsulated absorbent.

[0046] If the above-mentioned bonding area is formed on the multipack (on which pressure must also be applied locally in order to adhesively connect two surface sections of different wall sections of the multipack bag to each other), then when the absorption area of the multipack, which is formed by incorporating at least one pressure-activated absorber of the oxygen absorber and the moisture absorber into the polymer layer exposed to the external packaging space, overlaps with the bonding area, the pressure applied for the connection and thus for closing the removal opening again can also be used in an advantageous manner to activate at least one absorber.

[0047] Furthermore, the multipack can be designed to generate and / or maintain a gas composition different from the normal atmosphere in the outer packaging space even after opening and closing again. For example, it can be provided that an activatable gas source with at least an oxygen-reduced gas is contained in the outer packaging space of the multipack. The activatable gas source can be a breakable container, which either directly contains the gas or contains a substance that is converted into the gas phase after the container is broken, optionally a plurality of substances, which are initially separated to form a mixture by breaking the container, wherein the mixture is converted into the gas phase.

[0048] The container can in turn be formed by a plurality of microcapsules which, as an alternative or in addition to the absorbent microcapsules, are contained in a polymer layer of the first packaging layer material of the multipack which is exposed towards the outer packaging space. Although the protective gas atmosphere obtainable with the aid of the microcapsules, for example with an atmosphere with an increased content of N2 or CO2, is weaker than the protective gas atmosphere obtainable with a fragile container, weaker is better than none. In this context, the quasi-inert gases nitrogen and carbon dioxide mentioned by way of example are referred to as protective gases, which do not combine with other chemical elements under normal conditions in the absence of an external energy source.

[0049] In order to provide the high barrier properties mentioned at the beginning, the first packaging layer material can have a metallized layer and / or a metal oxide layer and / or a vinyl alcohol-containing polymer layer as a barrier layer for reducing the migration of oxygen and / or moisture through the first packaging layer material. The metallized layer can be physically or chemically deposited from the vapor phase onto the surface of the carrier polymer layer or onto the surface of the carrier polymer layer according to methods known per se. The same applies to the metal oxide layer. The metallized portion can be formed by any metal. Preferably, the metallized portion is formed by aluminum or an aluminum alloy. For the metal oxide layer, materials with the structural name SiO are particularly considered. x of silicon oxide and has the structural name Al u O v wherein x, u and v are integers. The most well-known aluminum-based metal oxide barrier material is Al2O3.

[0050] The carrier polymer layer on which a metal or metal oxide layer is vapor-deposited or vapor-phase deposited is preferably formed of an oriented polymer, particularly preferably a biaxially oriented polymer. Polypropylene is particularly suitable for biaxial orientation.

[0051] As the ethylene alcohol polymer having a barrier effect, the EVOH and PVOH mentioned at the beginning can be considered.

[0052] To simplify the recycling of the co-packaging after its use, preferably, at least 90% by weight, preferably at least 95% by weight of the first packaging layer material is formed of a polymer of the same monomer. Then, the first packaging layer material can be recycled in a single-material recycling stream. Preferably, the material is a polyolefin, particularly preferably polypropylene. However, it should not be excluded that the co-packaging is formed of a packaging layer material having different variants of polyethylene and at least 90% by weight, preferably at least 95% by weight is composed of polyethylene.

[0053] For the same reason, additionally or alternatively, at least 90% by weight, preferably at least 95% by weight of the second packaging material is formed of a polymer of the same monomer. Since usually at least the last removed individual package and the subsequently unnecessary co-packaging are removed together, the first and second packaging materials are preferably at least 90% by weight, preferably at least 95% by weight formed of the same polymer.

[0054] The first packaging layer material can, for example, have the following structure from the outside to the inside, i.e., towards the outer packaging space:

[0055] a.) A layer composed of biaxially oriented polypropylene, having a thickness between 15 μm and 30 μm, preferably between 17 μm and 23 μm, particularly preferably 20 μm,

[0056] b.) A layer coated with a printing pigment protected from the outside by layer a.) in reverse printing,

[0057] c.) An adhesion promoter layer, which is either composed of an adhesive, such as a polyurethane-based adhesive, having a unit area weight between 2 g / m 2 and 5 g / m 2 preferably between 3 g / m 2 and 4 g / m 2 particularly preferably 3.5 g / m 2 or as an extrusion adhesive layer composed of polypropylene, having a unit area weight between 12 g / m 2 and 20 g / m 2 preferably between 13 g / m 2 and 17 g / m 2 particularly preferably 15 g / m 2

[0058] d.) If the layer c.) is an extrusion-bonded layer made of polypropylene, then an optional primer layer,

[0059] e.) A metallized layer made of aluminum or a metal oxide layer made of SiO x or Al u O v where x, u, and v are integers, carried by the following

[0060] f) A carrier polymer layer made of biaxially oriented polypropylene, having a thickness between 15 μm and 25 μm, preferably between 16 μm and 20 μm, and particularly preferably 18 μm,

[0061] g) An adhesive layer similar to the adhesive layer c.), having the same material and unit area weight range, provided that in the case of forming an adhesive layer, the particularly preferred unit area weight is 3.0 g / m 2 , and

[0062] h.) A polypropylene layer, preferably a polypropylene layer made by casting or blow molding polypropylene. Preferably, the layer h.) is provided with a dye, particularly preferably a white dye. The thickness of the layer h.) is preferably between 40 μm and 100 μm, particularly preferably between 50 μm and 70 μm, and more preferably 60 μm. The layer h.) can be co-extruded from multiple sub-layers. The layer h.) can in particular be formed of sealable polypropylene on its exposed surface.

[0063] The second packaging layer material can for example have the following structure from the outside in, i.e., towards the outer packaging space:

[0064] a.) A layer made of polypropylene, preferably made by casting or blow molding polypropylene, having a thickness between 25 μm and 40 μm, preferably between 27 μm and 33 μm, and particularly preferably 30 μm,

[0065] b.) An adhesive layer, which is either made of an adhesive, such as a polyurethane-based adhesive, having a unit area weight between 2 g / m 2 and 5 g / m 2 , preferably between 3 g / m 2 and 4 g / m 2 , and particularly preferably 3.5 g / m 2 , or as an extrusion-bonded layer made of polypropylene, having a unit area weight between 12 g / m 2 and 20 g / m 2 , preferably between 13 g / m 2 and 17 g / m 2 , and particularly preferably 15 g / m 2

[0066] c.) a polypropylene layer, preferably a polypropylene layer made of cast or blown polypropylene. Preferably, layer c) is provided with a dye, particularly preferably a white dye. The thickness of layer c.) is preferably between 40 μm and 100 μm, particularly preferably between 50 μm and 70 μm, and more preferably 60 μm.

[0067] Layer c.) can be co-extruded from multiple sub-layers. Layer c.) can in particular be formed of sealable polypropylene at its exposed surface.

[0068] The layer a.) of the second packaging layer material can carry an EVOH layer on its side facing the interior packaging volume, for example based on co-extrusion, in order to also impart a certain barrier effect to the second packaging layer material. If the EVOH layer is formed between the layer made of polypropylene mentioned and the additive layer, the thickness of said layer is between 20 μm and 50 μm.

[0069] As has been confirmed, when at least one of the given additive layers is formed by an extruded polypropylene layer, the bursting strength of the co-packaging is higher, said extruded polypropylene layer being used to squeeze-bondingly connect the outer BoPP layer to the metallization on the carrier polymer layer made of BoPP or / and to connect the carrier polymer layer to the inner layer made of cast or blown polypropylene instead of by interposing an adhesive layer, such as an adhesive layer made of polyurethane. The current theory explains this situation as follows: The squeeze-bonded connection made of polypropylene has a higher internal damping compared to the sticky adhesive connection by means of adhesive coating. The polypropylene layer for squeeze bonding is generally less rigid or has a smaller elastic modulus and is thicker compared to the adhesive coating carried out instead of squeeze bonding. Here, the bursting strength is tested by dropping the packaging system from a height of 1 m and 1.5 m onto a flat hard substrate made of, for example, concrete, ceramic or stone.

[0070] The assembled package in the first closed state after filling contains gas and two or more individual packages. The gas can be normal air, or it can be a protective gas atmosphere composed of an inert gas or a quasi-inert gas that is favorable in terms of its cost, such as nitrogen or carbon dioxide. Tests have shown here that in order to achieve the best possible bursting strength, it is advantageous for a larger part of the volume of the outer packaging space to be occupied by the individual packages and only a smaller part of the volume of the outer packaging space to be occupied by the gas. Preferably, the volume occupied by the individual packages in the outer packaging space is 2 to 5 times larger than the volume occupied by the gas in the outer packaging space. A further improvement in the bursting strength can be achieved by having an overpressure in the outer packaging space relative to the outer surroundings of the assembled package, where the overpressure is preferably 1.1 to 1.3 times the pressure of the outer surroundings outside the assembled package. In case of doubt, the overpressure situation is checked at a room temperature of 20 °C. Thus, if a pressure of 1013 hPa exists as the standard atmospheric pressure in the outer surroundings of the assembled package at a room temperature of 20 °C, then preferably a pressure of 1114 hPa to 1317 hPa exists in the outer packaging space. Description of the Drawings

[0071] The present invention will be described in detail below with reference to the drawings. The drawings show:

[0072] Figure 1 A roughly schematic perspective view of an embodiment according to the invention of the packaging system of the present application,

[0073] Figure 2 showing through Figure 1 a roughly schematic cross-sectional view of the closure strip of the assembled package,

[0074] Figure 3 showing through Figure 1 a roughly schematic cross-sectional view of the first packaging layer material of the assembled package, and

[0075] Figure 4 showing through Figure 1 a roughly schematic cross-sectional view of the second packaging layer material of the individual package. Detailed Description of the Invention

[0076] In Figure 1Only schematically and by way of example, the packaging system of the present invention is shown generally designated by 10. The packaging system 10 includes an outer co-packaging 12 in the form of a sealed-edge bag in only an exemplary selected configuration, which has a folded bottom at its lower end 12a. A separate packaging 16 in the form of a four-sided sealed bag in only an exemplary selected configuration, indicated by dashed lines, is accommodated in the outer packaging space 14 surrounded by the co-packaging 12. For example, prefabricated vegetables such as carrots, peas, beans, potatoes, etc. are accommodated in the separate packaging 16. Thus, the separate packaging 16 is sterilized by hot steam at a temperature between 120°C and 135°C by the known distillation tube sterilization method before it is wrapped in the co-packaging 12. Here, the separate packaging 16 is subjected to an elevated temperature for a period between 10 minutes and 120 minutes.

[0077] The remaining volume of the outer packaging space 14 is filled with a quasi-inert gas, currently for example with dry nitrogen, in order to delay the action of oxygen and moisture (water vapor) on the vegetables packaged in the separate packaging 16 for as long as possible.

[0078] The co-packaging 12 is made of a one-piece first packaging layer material 18, which is folded back onto itself in its lower end region 12a and is closed by a surrounding sealing edge 20 under the condition of forming the outer packaging space 14.

[0079] In its top region 12b, a desired cutting line 22 for forming a removal opening is graphically shown on the outer side 18a of the first packaging layer material 18. By cutting along the desired cutting line 22, the top region 12b together with the laterally extending section of the sealing edge 20 is separated from the rest of the co-packaging 12. After this separation, the outer packaging space 14 can be used to remove one or more separate packagings 16.

[0080] Since usually only a part of the total separate packagings 16 packaged in the co-packaging 12 is removed during the first removal process, while the remaining part of the separate packagings 16 remains in the outer packaging space 14 of the co-packaging 12, the co-packaging 12 has a closing device 24, which can effect the re-closing of the removal opening formed along the desired cutting line 22.

[0081] Thus, the closing device 24 has for example a so-called "zipper" 26, which has two mutually opposed closing strips 26a and 26b. The zipper 26 is located between the front packaging wall 12c of the co-packaging 12 facing Figure 1 the observer and the rear packaging wall 12d of the co-packaging 12 facing away Figure 1 from the observer, and is fastened at its respective mutually facing inner sides (also see Figure 2 ). The zipper 26 forms the form-fitting device mentioned in the summary of the description.

[0082] In addition, in the illustrated embodiment, the closing device 24 has an adhesive zone 28 on the side of the zipper 26 facing the packaging space 14, on the inside of the front packaging wall 12c of the combined package 12. The adhesive zone has a cold adhesive applied to the inside of the front packaging wall 12c. The adhesive zone 28 can first be covered by a strip made of release material in the first closed state in order to prevent its adhesive effect on the opposite inside of the rear packaging wall 12d of the combined package 12. After removing the strip made of release material, the adhesive zone 28 is exposed towards the opposite inside of the rear packaging wall 12d. Alternatively, the adhesive zone 28 can be detachably adhesively connected to the inside of the rear packaging wall 12d, such that in order to open the combined package 12 for the first time, in addition to separating the top region 12b, it is also necessary to separate the front packaging wall and the rear packaging wall 12c or 12d.

[0083] In addition, the closing device 24 has a further adhesive zone 30 made of cold adhesive on the outside, i.e., on the outer side of the rear packaging wall 12d remote from the outer packaging space 14. The further adhesive zone enables the combined package 12 to be rolled up from the access opening towards the lower region 12b and the resulting roll to be fixed "outer to outer" by the further adhesive zone 30. The further adhesive zone 30, which like the adhesive zone 28 has a pressure-sensitive cold adhesive on one of the insides of the packaging walls 12c or 12d, is covered by release material before its activation. The release material can be, for example, a strip made of paper coated with silicone resin, etc. By covering the further adhesive zone 30, it is prevented that the area on the outside of the combined package 12 is sticky and that a part of the consumer's clothing or hand is undesirably stuck by the further adhesive zone 30.

[0084] After opening the combined package 12, the initially contained quasi-inert protective gas atmosphere escapes. In order to be able to reduce the absolute content of oxygen and moisture in the outer packaging space 14 after re-closing, a valve 32 is provided in the packaging wall, in the illustrated example in the front packaging wall 12c of the combined package 12, through which gas can be squeezed from the outer packaging space 14 into the external environment U of the combined package 12, for example by manually pressing the combined package 12 together to reduce the volume of its outer packaging space 14.

[0085] In order to be able to reduce the oxygen and moisture content of the gas atmosphere in the interior of the outer packaging space 14 in addition to the absolute gas content, in the illustrated example, the inside of the front packaging wall 12c or the polymer layer 54 exposed towards the outer packaging space 14 (see Figure 3) has an absorbent zone 34 thereon or therein, in which a microencapsulated oxygen absorbent and a moisture absorbent are accommodated. By the local pressure onto the absorbent zone 34, the microcapsules can rupture and the corresponding absorbents are released, such that the absorbents act on the gas atmosphere in the outer packaging space 14 and absorb oxygen as well as moisture.

[0086] The absorbent zone 34 overlaps with the adhesive zone 28, such that when the composite package 12 is closed again via the adhesive zone 28, pressure is already applied onto the absorbent zone 34, thereby activating at least a part of the absorbents provided there.

[0087] Additionally or alternatively, at least one breathable bag 36 can be accommodated in the outer packaging space 14, which has an oxygen absorbent and / or a moisture absorbent, in order to permanently extract oxygen and moisture from the gas atmosphere in the outer packaging space 14.

[0088] Furthermore, additionally or alternatively, a container 38 as a source of quasi-inert gas can be accommodated in the outer packaging space 14. After the composite package 12 is closed again, the container 38 can rupture, such that a quasi-inert gas-rich and thus oxygen- and moisture-poor atmosphere is re-generated in the outer packaging space 14 at least within certain limits.

[0089] In Figure 2 a cross-section shows the zipper 26 of the form-fitting device 24. Figure 2 The drawing plane of

[0090] extends orthogonally to the extension direction of the closure strips 26a and 26b of the zipper 26, which are preferably formed by extrusion. In the illustrated example, the closure strip 26a includes a core strip 26a1 formed of polyamide, which is connected to the inner side 12e of the front packaging wall 12c, for example, by an adhesive connection. The core strip 26a1 has a positive form-fitting structure 40, which can be introduced into a negative form-fitting structure 42 of a core strip 26b1 of the closure strip 26b of the zipper 26, which is connected to the inner side 12f of the rear packaging wall 12d and is preferably also formed of polyamide, and is locked with the negative form-fitting structure in a releasable manner.

[0091] Along the entire length of the closure strips 26a and 26b, the core strips 26a1 and 26b1 carry two barrier structures 26a2 and 26a3 or 26b2 and 26b3, respectively. The barrier structures are formed of a vinyl alcohol polymer, in the illustrated example of EVOH, and improve the barrier properties of the zipper 26 in the closed state against oxygen migrating through the zipper 26 from the external environment U into the outer packaging space 14. The core strips 26a1 and 26b1 form a moisture barrier such that the zipper 26 generally not only significantly impedes oxygen migration through the closed zipper 26 but also significantly impedes moisture migration through the closed zipper 26. The dimensions of the barrier structures 26a2 and 26a3 on the one hand and the barrier structures 26b2 and 26b3 on the other hand are determined such that, in the case of the closed zipper 26, the barrier structures 26a2 and 26b2 abut against each other in a butting manner, and the same applies to the barrier structures 26a3 and 26b3. Thus, only small gaps remain as unbarriered migration paths through the closed zipper 26, but the migration paths are deflected multiple times by the design of the form-fitting structures 40 and 42, thereby forming a labyrinth seal that also makes it difficult for oxygen and moisture to migrate through the closed zipper 26.

[0092] In Figure 3 a cross-section is schematically shown in a rough manner of an exemplary feasible design through the first packaging layer material 18. The side 18a of the first packaging layer material 18 is the outer side facing the consumer. The opposite side 18b is the side facing the outer packaging space 14 at the completed combined packaging 12.

[0093] The outer side 18a is formed by a layer composed of biaxially oriented polypropylene (BoPP) 44, and the layer is provided with a layer 46 composed of printing pigments in reverse printing on the side opposite to the outer side 18a, so as to provide consumer information at the combined packaging 12 in a manner perceptible by the consumer while protecting against the influence of the external environment U through the layer 44. The layer 44 has a preferred thickness of 20 μm. The layer 46 composed of printing pigments is significantly thinner than the layer 44, and its thickness is related to the amount of printing pigments printed onto the layer 44 in reverse printing.

[0094] The first packaging layer material 18 further has a biaxially oriented polypropylene layer 48 as a carrier polymer layer, and the carrier polymer layer has a metallized layer 50 deposited by vapor phase on the side remote from the outer packaging space 14. The metallized BoPP layer 48 (more precisely: the metallized layer 50 carried by it) is adhesively bonded to the layer 46 composed of printing pigments by an adhesive 52 composed of polyurethane provided in between. The adhesive layer 52 composed of polyurethane has a unit area weight of preferably 3.5 g / m 2 The carrier polymer layer 48 has a preferred thickness of 18 μm. The deposited metallized layer 50 generally has a thickness of less than 1 μm.

[0095] The inner side 18b of the first packaging layer material 18 is formed by an unstretched layer 54 made of polypropylene. The layer 54 can be formed by cast or blown polypropylene. The layer does not have an orientation of its polypropylene that extends beyond the molecular orientation caused by the conventional production of cast or blown polypropylene films, such as by calendering, and the layer is sealable such that the sealing edge 20 of the combined package 12 is formed by zone-by-zone heat sealing of the layers 54 of the folded first packaging layer material 18 that are in contact with each other. The layer 54 has a preferred thickness of 60 μm.

[0096] The layer 54 is extrusion-bonded to the carrier polymer layer 48 made of biaxially oriented polypropylene through an intermediate extruded layer 56 made of polypropylene. By means of an additional polypropylene layer 56 having a unit area weight of approximately 15 g / m 2 extrusion-bonding the layer 54 to the layer 48 significantly increases the burst strength of the combined package 12 or the packaging system 10 when dropped from a height of 1 m or 1.50 m onto a hard substrate. The reason for this may be the internal friction and damping of the extrusion-bonding layer 56 made of polypropylene, which is thicker, for example 5 to 8 times thicker, than an adhesive layer of the same function made of polyurethane. However, the adhesive layer of the same function made of polyurethane can be used instead of the extrusion-bonding layer 56.

[0097] The metallization layer 50 imparts very good barrier properties to the first packaging layer material 18 with respect to the migration of oxygen and moisture through the first packaging layer material 18, wherein the oxygen transmission rate is less than 0.5 cm 3 / (m 2 ·d·bar) and the water vapor transmission rate is less than 0.5 g / (m 2 ·d).

[0098] In Figure 4 a schematic cross-section through the second packaging layer material 60 is shown, in the illustrated embodiment, the individual package 16 is formed by the second packaging layer material.

[0099] The outer side 60a of the second packaging layer material 60 facing away from the inner packaging space 70 is formed by a layer 62 made of polypropylene, preferably blown polypropylene. The layer 62 does not have an orientation of its polypropylene that extends beyond the orientation caused by the conventional production of blown polypropylene films, such as by calendering. The layer 62 has a preferred thickness of 30 μm.

[0100] The inner side 60b facing the inner packaging space 70 is formed by a layer 64 made of cast or blown polypropylene. The layer 64 also does not have a molecular orientation of its polypropylene that extends beyond the orientation caused by the conventional production of cast or blown polypropylene films, for example by calendering. The layer 64 is preferably 60 μm thick and is white dyed. The layer is sealable such that the individual package 16 can be formed by thermally sealing the inner sides 60b of the second packaging layer material 60 against each other.

[0101] In order to be able to manufacture the individual package 16 as rupture-resistant as possible, the two outer layers 62 and 64 are preferably connected to each other by an extrusion adhesive layer 66 made of polypropylene. The extrusion adhesive layer 66 preferably has a coating weight of 15 g / m 2 .

[0102] The layer thicknesses mentioned are preferred layer thicknesses. The thickness of each layer composed of the first and second packaging layer materials can be within the thickness ranges mentioned for the respective layers in the overview section of the specification.

[0103] Not only the first packaging layer material 18 but also the second packaging layer material 60 each have a polypropylene weight fraction of more than 90%, preferably even more than 95%, so that each of the packages 12 or 16 formed therefrom can be recycled in the monomer material recycling stream.

[0104] Alternatively, an oxygen barrier layer 68 made of EVOH can be provided between the layer 62 and the extrusion adhesive layer 66, and the oxygen barrier layer has a thickness between 20 μm and 50 μm. The EVOH layer 68 can be produced by co-extrusion with the polypropylene layer 62.

[0105] Although the EVOH layer 68 cannot withstand the steam tube sterilization process applied especially to food packaging without damage, however, the optional additional EVOH layer 68 can improve the performance of the packaging system 10. The EVOH layer 68 may suffer from a so-called "steam tube shock" during steam tube sterilization, which reduces the oxygen barrier properties of the EVOH layer, i.e., numerically increases the oxygen transmission rate that can generally be achieved by the second packaging layer material 60. On the one hand, the oxygen transmission rate through the second packaging layer material is reduced until the steam tube shock. On the other hand, compared with the same packaging layer material without the EVOH layer 68, the second packaging layer material 60 with the EVOH layer 68 but with the steam tube shock still always has a lower oxygen transmission rate. Therefore, the individual package 16 formed by the second packaging layer material 60 with the EVOH layer 68 protects the product packaged therein against oxygen entry until the individual package 16 is packaged in the combined package 12.

[0106] As expressed by the term "distillation tube shock", the oxygen barrier effect that is first significantly reduced by distillation tube sterilization is not permanent. A portion of the oxygen barrier effect lost during distillation tube sterilization is restored over time, presumably through plastic flow of the EVOH within the layer formed by the EVOH. The theory of the restoration of the oxygen barrier effect after distillation tube sterilization and distillation tube shock is not fully clarified, yet it can be demonstrated phenomenologically.

[0107] The oxygen transmission rate of the second packaging layer material 60 having the EVOH layer 68 is also still higher than that of the first packaging layer material 18, at least six times higher.

Claims

1. A packaging system (10) capable of thermal sterilization, said packaging system comprising an outer combined packaging (12), said combined packaging surrounding an outer packaging space (14), in which at least two inner individual packages (16) are accommodated, wherein each individual package (16) surrounds an inner packaging space (70) and is configured for packaging a product, wherein said combined packaging (12) is formed of a first packaging material (18), said first packaging material comprising at least one polymer layer (44, 48, 52, 54, 56) as the packaging layer material (18), and wherein said individual packages (16) are formed of a second packaging material (60) different from said first packaging material, wherein one of the first packaging layer material and the second packaging material (18, 60) has an oxygen transmission rate of less than 0.5 cm3 / (m 2 ··d··bar) determined according to DIN 53380-3 at 23 °C and 85% relative humidity and a water vapor transmission rate of less than 0.5 g / (m2··d) determined according to ISO 15106-2 at 23 °C and 85% relative humidity as a high-barrier packaging material, and wherein the corresponding other one of the first packaging layer material and the second packaging material (18, 60) has an oxygen transmission rate of greater than 3 cm3 / (m 2 ··d··bar) determined according to DIN 53380-3 at 23 °C and 85% relative humidity and a water vapor transmission rate of greater than 2 g / (m 2 ··d) determined according to ISO 15106-2 at 23 °C and 85% relative humidity as a low-barrier packaging material, Characterized in that, the first packaging material (18) has at least two polymer layers (44, 48, 52, 54, 56) and is the high-barrier packaging material, and the second packaging material (60) is a packaging layer material (60) having at least one polymer layer (62, 64, 66, 68) and is the low-barrier packaging material.

2. The heat-sterilizable packaging system (10) according to claim 1, Characterized in that, the combined package (12) has a closing device (24) for re-closing the access opening.

3. The heat-sterilizable packaging system (10) according to claim 2, Characterized in that, the closing device (24) includes a form-fitting device, wherein the form-fitting device has, on each side of the access opening, a closing strip (26a, 26b) extending along the access opening, wherein one of the closing strips (26a) has a positive form-fitting structure (40) extending along the access opening in the longitudinal direction of the one closing strip (26a), and wherein the corresponding other closing strip of the closing strips (26a, 26b) has a negative form-fitting structure (42) extending along the access opening in the longitudinal direction of the corresponding other closing strip (26b) for form-fittingly receiving the positive form-fitting structure (40), wherein each of the closing strips (26a, 26b) is at least partially formed of an ethylene alcohol polymer.

4. The heat-sterilizable packaging system (10) according to claim 3, Characterized in that, at least one of the closing strips (26a, 26b) has a core strip (26a1, 26b1) made of a polymer material different from the ethylene alcohol polymer and extending in at least 70% of its longitudinal dimension, wherein the core strip (26a1, 26b1) bears a barrier structure (26a2, 26a3, 26b2, 26b3) made of an ethylene alcohol polymer in at least 90% of its longitudinal dimension in at least sections.

5. The heat-sterilizable packaging system (10) according to claim 4, Characterized in that, each of the two closing strips (26a, 26b) has a core strip (26a1, 26b1) made of a polymer material different from the ethylene alcohol polymer and extending in at least 70% of its longitudinal dimension, wherein each core strip (26a1, 26b1) bears a barrier structure (26a2, 26a3, 26b2, 26b3) made of an ethylene alcohol polymer in at least 90% of its longitudinal dimension in at least sections, and wherein in the closed state of the form-fitting device, when the positive and negative form-fitting structures (40, 42) are in form-fitting engagement with each other, the barrier structures (26a2, 26a3, 26b2, 26b3) of the two closing strips (26a, 26b) are in contact with each other in at least 80% of the engagement length of the form-fitting structures (40, 42).

6. The heat-sterilizable packaging system (10) according to any one of claims 3 to 5, characterized in that, the shape mating device includes a slider displaceable along the closure strip (26a, 26b) as an operating aid for operating the shape mating device, wherein the slider surrounds the closure strip (26a, 26b), and when moving in the direction of the longitudinal dimension of the closure strip (26a, 26b), at least supports the establishment of a shape mating engagement between the positive shape mating structure and the negative shape mating structure (40, 42), and when moving in the opposite direction, at least supports the removal of the shape mating engagement between the positive shape mating structure and the negative shape mating structure (40, 42).

7. The heat-sterilizable packaging system (10) according to any one of claims 2 to 6, characterized in that, the closure device (24) has adhesive zones (28, 30) with cold adhesive, wherein the cold adhesive is provided on the surface of the packaging wall section (12c) of the combined package (12) for adhesively connecting to another packaging wall section (12d) of the combined package (12).

8. The heat-sterilizable packaging system (10) according to claim 7, characterized in that, the combined package (12) is a combined packaging bag having a front packaging wall (12c) and a rear packaging wall (12d), and the external packaging space (14) is between the front packaging wall and the rear packaging wall, wherein the cold adhesive zones (28, 30) are provided: i.) on the inner side (12e, 12f) of one of the front packaging wall and the rear packaging wall (12c, 12d) facing the corresponding other packaging wall (12d, 12c) for adhesively connecting to the inner side (12f, 12e) of the corresponding other packaging wall (12d, 12c), or / and ii.) on the outer side (18a) of one of the front packaging wall and the rear packaging wall (12c, 12d) facing away from the corresponding other packaging wall (12d, 12c) for adhesively connecting to the outer side (18a) of the corresponding other packaging wall (12d, 12c).

9. The heat-sterilizable packaging system (10) according to any one of the above claims, characterized in that, a valve (32) is provided in the wall section of the combined package (12), through which gas can flow from the external packaging space (14) to the external surrounding environment (U) of the combined package (12), but cannot flow in the opposite direction.

10. The heat-sterilizable packaging system (10) according to any one of the above claims, characterized in that, the combined package (12) has at least one absorbent of an oxygen absorbent and a moisture absorbent.

11. The heat-sterilizable packaging system (10) according to claim 10, characterized in that, At least one of the oxygen absorbent and the moisture absorbent is pressure-activably incorporated in a polymer layer exposed towards the outer packaging space.

12. A heat-sterilizable packaging system (10) according to claim 11, under the conditions of claim 7, characterized in that an absorbent zone (34) formed in the co-packaging (12) by incorporating at least one pressure-activable absorbent of the oxygen absorbent and the moisture absorbent into a polymer layer (54) exposed towards the outer packaging space (14) overlaps with the adhesive zones (28, 30).

13. A heat-sterilizable packaging system (10) according to any one of the above claims, characterized in that an activatable gas source (38) having a gas with at least reduced oxygen is accommodated in the outer packaging space (14) of the co-packaging (12).

14. A heat-sterilizable packaging system (10) according to any one of the above claims, characterized in that the first packaging layer material (18) has a metallized layer (50) or / and a metal oxide layer or / and a polymer layer containing vinyl alcohol as a barrier layer for reducing the migration of oxygen or / and moisture through the first packaging layer material (18).

15. A heat-sterilizable packaging system (10) according to any one of the above claims, characterized in that at least 90% by weight of the first packaging layer material (18) is formed from a polymer of the same monomer or / and at least 90% by weight of the second packaging layer material (60) is formed from a polymer of the same monomer.

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