Flexible laminated structure comprising a heat-sealable polyolefin layer with a layer of a metal-based material deposited thereon

Abstract

The invention relates to a flexible laminated structure (10) for producing packaging, comprising: - a base layer assembly (18), - a barrier layer assembly (24) comprising a carrier polymer layer (21) with a layer (22) of a metal-based material deposited thereon, - a polymer connecting layer (26) which connects the barrier layer assembly (24) to the base layer assembly (18), and - a sealable polyolefin layer (20). According to the invention, the sealable polyolefin layer (20) is the carrier polymer layer (21) so that the barrier layer assembly (24) is a sealable barrier layer assembly (24), and the polymer connecting layer (26) is a polyolefin connecting layer (26) which connects the barrier layer assembly (24) to the base layer assembly (18).

Description

[0001] 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0002] - 1 -

[0003] Flexible layered composite with a heat-sealable polyolefin layer and a layer of metal-based material deposited on top.

[0004] Description

[0005] The present invention relates to a flexible layer composite for the production of packaging, in particular food packaging, and even more preferably packaging for liquids and liquid foodstuffs.

[0006] The flexible layered composite comprises a base layer arrangement, a barrier layer arrangement supported by the base layer arrangement, a polymer bonding layer connecting the barrier layer arrangement to the base layer arrangement, and a sealable polyolefin layer. Cardboard composites with a cardboard layer as a stability-determining base layer in the base layer arrangement are known as such flexible layered composites for packaging liquid foods. Cardboard composites with an aluminum foil layer as an oxygen and water vapor barrier in the barrier layer arrangement have also been known for some time. The aluminum foil layer is bonded to the cardboard layer of the base layer arrangement via the polymer bonding layer, in this case usually a polyolefin layer.The base layer arrangement can have one or more layers of print job for providing consumer information on the side of the cardboard layer facing away from the barrier layer arrangement, as well as an outer protective layer protecting the at least one print job.

[0007] On the side of the aluminium foil layer facing away from the cardboard layer, a sealable polyethylene layer is arranged on the known cardboard composites with an intermediate adhesive layer, the sealable surface of which is exposed.

[0008] For some time now, the packaging industry has been striving to replace the aluminum foil layer with a suitable alternative barrier layer. The aluminum foil layer is energy-intensive to produce and therefore expensive to procure, and after use, packaging made with the flexible layer composite presents difficulties in disposal or recycling. 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0009] - 2 -

[0010] A well-known alternative barrier layer to the aluminum foil layer is a carrier polymer layer with a metal base layer made of a metal-based material deposited on it.

[0011] Such a flexible layer composite with an alternative barrier layer is known, for example, from WO 2011 / 003565 A2. This publication discloses in more detail a flexible layer composite with a paper layer having a basis weight of, for example, 50 g / m². 2as part of the base layer arrangement. A polymer compound layer made of polyvinyl alcohol (PVOH) is applied as a liquid dispersion to the side of the paper layer that will later face the packaged product.

[0012] The polymer bonding layer is coated with a metallization. Thus, in the flexible layer composite known from WO 2011 / 003565 A2, the polymer bonding layer is the carrier polymer layer. It forms, as it were, a combined, function-integrated carrier-polymer bonding layer.

[0013] On the side of the metallization facing away from the paper layer, a heat-sealable layer is arranged, comprising LDPE (low-density polyethylene) and / or LLDPE (linear low-density polyethylene) and / or metallocenes LLDPE (m-LLDPE). The heat-sealable layer can be extruded onto the metallization or laminated on in the conventional manner.

[0014] WO 2011 / 003565 A2 emphasizes, firstly, the necessity of applying the polymer compound layer as a dispersion in the liquid state, in order to make the polymer compound layer as thin as possible with an application weight of no more than 5 g / m². 2 to apply, and secondly emphasizes the necessary selection of the polymer of the combined carrier and polymer bonding layer such that its melting point or softening point is significantly higher than the melting point or softening point of the heat-sealable layer. This is to ensure that the thin carrier-polymer bonding layer remains intact during heating of the sealable polymer layer. 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0015] - 3 -

[0016] One of the ideas presented in WO 2011 / 003565 A2 is to use the vapor-deposited or vapor-deposited metallization as a heat source during heat sealing. For this purpose, the metallization is to be heated inductively by means of an external, changing magnetic field, through eddy currents that form within the metallization. The metallization then conducts this heat to its adjacent layers. The aim of WO 2011 / 003565 A2 is to soften only the heat-sealable layer, but not the combined carrier-polymer bonding layer.

[0017] Despite the successful avoidance of using aluminum foil in the flexible layer composite, the layer composite known from WO 2011 / 003565 A2 still has disadvantages. Firstly, the material used for the combined carrier-polymer bonding layer is exceptionally expensive, which is why, according to WO 2011 / 003565 A2, it is applied only very thinly as a dispersion. Secondly, metallization can only be vapor-deposited onto the combined carrier-polymer bonding layer after it has been applied to the base layer arrangement, i.e., the paper layer. The process of physical vapor deposition of metal onto a substrate is a discontinuous process, which proceeds more slowly the more mass has to be introduced into the deposition chamber for each step. Therefore, the paper layer supporting the carrier-polymer bonding layer is a comparatively thin paper layer with the specified basis weight of 50 g / m². 2Since this paper layer does not usually provide sufficient stability for a liquid package, the base layer arrangement must be supplemented with another layer of paper or cardboard in order to obtain a package with sufficient strength, such as burst resistance.

[0018] The object of the present invention is to improve the aforementioned aluminium foil-free flexible layer composite with regard to the aforementioned disadvantages.

[0019] This problem is solved by the present invention with a flexible layer composite having all the features of claim 1. Since the sealable polyolefin layer is the carrier polymer layer, the metal base layer can be applied to the base layer, which is more flexible compared to the base layer. 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0020] - 4 - In the layer arrangement of the layer composite known from WO 2011 / 003565 A2, a significantly lower mass sealable polyolefin layer can be deposited per unit area. The sealable polyolefin layer in the flexible layer composite is therefore a prefabricated sealable polyolefin film. The deposition process can thus be carried out considerably shorter and consequently more cost-effectively with the same thickness of deposited metal base layer. The barrier layer arrangement of the flexible layer composite according to the invention is therefore a sealable barrier layer arrangement.

[0021] Surprisingly, the inventors of the flexible composite material applied for here have found that the temperature resistance of the polymer layers adjacent to the metal base layer—the polymer bonding layer and the sealable polyolefin layer—is not actually critical. A polyolefin bonding layer, which is considerably less expensive than the polymer bonding layer made of PVOH preferred according to WO 2011 / 003565 A2 and which largely comprises or consists of polyolefin, can readily be used if it is of sufficient thickness.

[0022] The layer structure of the flexible composite can therefore be kept simple. The flexible composite can be manufactured cost-effectively with sufficient process reliability and operational safety in its subsequent use as packaging material.

[0023] In the present application, a "layer arrangement" refers to a single layer or a layered body consisting of two or more interconnected layers. In contrast, according to the terminology used in the present application, a "layer composite" always comprises more than one layer.

[0024] The sealable polyolefin layer, as the carrier polyolefin layer of the sealable barrier layer assembly, has an exposed polyolefin surface and is ready to be bonded to another compatible polyolefin surface by heat sealing. Accordingly, the polyolefin bonding layer between the base layer assembly and the metal base layer of the sealable barrier layer assembly is preferably 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0025] - 5 - capable barrier layer arrangement. The metal base layer is therefore preferably located between the polyolefin compound layer and the carrier polyolefin layer, which is also the sealable polyolefin layer.

[0026] Depending on the metal-based material used in the deposited metal base layer, the choice of the surface exposed to the metal base layer from the base layer arrangement, and the polyolefin composition used in the polyolefin compound layer, different configurations of the bond between the metal base layer and the base layer arrangement can result in a sufficiently strong bond between the sealable barrier layer arrangement and the base layer arrangement. Accordingly, the bond between the base layer arrangement and the metal base layer of the sealable barrier layer arrangement can consist of either i. only the polyolefin compound layer, or ii. only the polyolefin compound layer with an adhesion promoter layer arranged on one side of the polyolefin compound layer between the polyolefin compound layer and the metallization, or iii.only the polyolefin compound layer with an adhesion promoter layer arranged on one side of the polyolefin compound layer between the polyolefin compound layer and the base layer arrangement, or iv. only the polyolefin compound layer and one adhesion promoter layer each arranged once between the polyolefin compound layer and the metal base layer and once again between the polyolefin compound layer and the base layer arrangement.

[0027] Without claiming to be exhaustive, for example a polyolefin composition such as that disclosed in WO 2023 / 144834 A1 and to which express reference is made herewith regard to a preferred polyolefin composition, can be applied directly to a metallization, i.e. to a metal base layer made of metal, in particular aluminium.

[0028] Other polyolefin compositions may require an adhesion promoter layer between the metal base layer, particularly in the form of a metal layer, for example 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0029] - 6 - consisting of ethylene-acrylic acid copolymer (EAA) or another suitable material known to experts for the adhesion promotion between a metal-based material and a polyolefin.

[0030] Preferably, the base layer arrangement has a surface of paper or cardboard exposed towards the sealable base layer arrangement prior to its connection with the barrier layer arrangement. A polyolefin bonding layer can be directly applied, in particular extruded, to this surface. If the base layer arrangement has a different initially exposed surface, an adhesion promoter layer can also be arranged between the base layer arrangement and the polyolefin bonding layer. The person skilled in the art selects the adhesion promoter layer based on their expert knowledge, taking into account the materials to be directly bonded.

[0031] Recycling of the flexible layer composite discussed here, or of packaging formed from it, is facilitated the fewer different materials are used to form the flexible layer composite. Therefore, preferably, the polyolefin of the carrier polyolefin layer of the sealable barrier layer arrangement and the polyolefin of the polyolefin bonding layer are based on the same olefin monomer. This allows the polyolefin of the carrier polyolefin layer and the polyolefin of the polyolefin bonding layer to be fed into the same recycling stream. Due to its sealing properties, the polyolefin of the carrier polyolefin layer, and thus of the sealable barrier layer arrangement, and the polyolefin of the polyolefin bonding layer are preferably both polyethylene. The polyolefin of the polyolefin bonding layer is preferably LDPE.Preferably, the sealable carrier polyolefin layer comprises LDPE, LLDPE, or m-LLDPE at least on its exposed sealing surface. The majority of the polyethylene mass in the sealable carrier polyolefin layer beyond the exposed sealing surface may comprise LDPE, MDPE, LLDPE, HDPE, or a blend of these materials.

[0032] A polyolefin layer referred to in the present application need not necessarily consist exclusively of polyolefin or of a preferably mentioned 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0033] - 7 -

[0034] Polyolefins, such as polyethylene, may be used, although this is not excluded. However, a polyolefin layer consists predominantly, i.e., at least more than 50 wt.%, of polyolefin. The polyolefin layer may contain additives to impart specific properties, such as color pigments, plasticizers, lubricants, various modifiers, and the like. For reasons of easier recycling, a polyolefin layer preferably consists of at least 90 wt.%, and even more preferably at least 95 wt.%, of polyolefin. As already explained above, polyethylene is a preferred olefin for the present application.

[0035] Although the sealable polyolefin layer is provided as a pre-fabricated polyolefin film and introduced into a deposition process to deposit the metal-based material onto the surface of the polyolefin film, the sealable polyolefin layer is also preferably without a specific molecular orientation, such as that achieved by targeted stretching. It has been found that molecularly oriented polyolefin films, i.e., axially or even biaxially oriented polyolefin films, exhibit better sealing properties than non-oriented polyolefin films with otherwise identical composition.

[0036] Since one surface of the sealable polyolefin film is preferably exposed as a polyolefin surface, the sealable polyolefin film is preferably only provided on one side with a metal base layer deposited on it.

[0037] Sufficient thickness of the polyolefin compound layer is preferably achieved by extrusion application, particularly preferably in a single application process. Thus, the extruded polyolefin compound layer can bond the barrier layer arrangement to the base layer arrangement immediately after application. However, it should not be excluded that the polyolefin compound layer is applied as a dispersion. The flowable dispersion mass forming the subsequent polyolefin compound layer can also be applied as a dispersion using the extrusion process. However, as a dispersion, it is not limited to this application method and can, for example, also be applied by rollers, optionally in several stages. 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0038] - 8 -

[0039] Application processes. Preferably, the flowable polyolefin material forming the subsequent polyolefin compound layer is thermally softened and applied via extrusion, so that simply cooling the extruded layer or extruded lamination layer leads to its solidification. Evaporation of a liquid dispersion matrix is ​​then not necessary, as with application as a dispersion.

[0040] To conserve resources and avoid unnecessary material consumption, the thickness of the polyolefin compound layer is preferably less than the thickness of the polyolefin layer in the sealable barrier layer assembly. The minimum thickness of the polyolefin compound layer, applied as an extrusion lamination layer, achieved through extrusion is sufficient to ensure adequate bond strength between the metal base layer and the base layer assembly, even when a metal base layer is inductively heated. While the polyolefin compound layer inevitably heats and softens during inductive heat sealing using the metal base layer, its thickness and the typically short sealing time ensure that sufficient bond strength is maintained at all times within the flexible layer assembly, even during an inductive heat sealing process.

[0041] For this purpose, the polyolefin compound layer with a coating weight of at least 9 g / m² is preferred. 2 applied. Even more preferably, the thickness of the polyolefin compound layer is selected to be in the range of 12 pm to 25 pm. This represents an optimum between efficient resource consumption and long-term bond strength in the flexible layer composite. A particularly preferred thickness of the polyolefin compound layer, especially when LDPE is used as the main component of the polyolefin compound layer, is in the range of 17 pm to 20 pm.

[0042] The polyolefin compound layer, preferably applied as an extrusion lamination layer or incorporated into the composite layer, naturally has no particular molecular orientation, apart from that which arises spontaneously during the application of the extrusion lamination layer. 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0043] - 9 -

[0044] Preferably, the thickness of the sealable carrier polyolefin layer of the sealable barrier layer composite is in the range of 25 pm to 60 pm. This allows sufficient seal strength to be achieved for the formation of beverage packaging with heavy contents of 1 liter of liquid or more. A particularly preferred thickness of the sealable carrier polyolefin layer is in the range of 37 pm to 42 pm.

[0045] The sealable carrier polyolefin layer can be constructed as a prefabricated carrier polyolefin film in a manner known per se from several individual layers of the same polyolefin, whereby the different individual layers may, but need not, exhibit different densities or different cross-linking structures despite using the same polyolefin. Preferably, the carrier polyolefin layer is produced as a blown film, where the multi-layered formation of a film is common practice.

[0046] In one embodiment, the deposited metal base layer can be a vapor-deposited metal oxide layer, such as a layer of aluminum oxide or silicon oxide known as a barium oxide layer. Since metal oxides are generally not electrical conductors but rather electrical insulators, inductive heating of the sealable polyolefin carrier layer is not possible with a vapor-deposited metal oxide layer. However, this is not particularly disadvantageous, as the heat required for heat sealing at the sealing surface can also be introduced by ultrasound or sonotrodes. Alternatively or additionally, the deposited metal base layer can be a vapor-deposited metal layer. Aluminum is the preferred metal for this purpose, although other metals are not excluded. A physical or chemical vapor deposition process is preferred, with the physical vapor deposition process being the preferred method.

[0047] The thickness of the metal base layer is preferably in the range of 5 nm to 300 nm. If inductive heating of the sealable carrier polyolefin layer is planned during subsequent processing of the flexible layer composite, an electrically conductive metal layer is preferred. Furthermore, if inductive heat input during sealing is planned, the thickness is preferably in the upper range. 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0048] - 10 -

[0049] Half of the specified range was chosen to ensure the formation of eddy currents in the metal layer and thus sufficiently rapid heating of the metal layer and its surroundings.

[0050] For reasons of advantageous environmental compatibility, the base layer arrangement comprises a fiber layer containing cellulose and / or lignin as the stability-determining base layer. Such a fiber layer can be a paper or cardboard layer with a basis weight of preferably 200 g / m². 2 up to 300 g / m² 2 , particularly preferably with a basis weight in the range of 240 g / m² 2 up to 280 g / m² 2 , even more strongly preferred from 260 g / m² 2 Furthermore, the fiber layer is preferably dyed to ensure its opacity. Brown has proven particularly advantageous in preventing or delaying the visibility of stains in the fiber layer, such as those that can occur, for example, when moisture penetrates the fiber layer due to a damaged inner coating.

[0051] According to another embodiment, a base layer arrangement may have more than one fiber layer, although this is not preferred with regard to efficient use of available resources.

[0052] In principle, a base layer of the base layer arrangement, which gives the base layer arrangement its essential stability and stiffness, can be any layer other than a fiber layer, such as a polyolefin layer or, more generally, a polymer layer.

[0053] To provide consumers, who are to be addressed by packaging made of flexible layers, with the necessary consumer information, the base layer arrangement can bear a printed layer on its side facing away from the sealable barrier layer arrangement, at a distance from it. Depending on the printing technique chosen, the printed layer can have one or more layers of ink in different colors. Since the fiber layer is particularly suitable for printing, 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0054] - 11 - preferably the printing layer is applied directly to a surface of the fiber layer.

[0055] To generally protect the outer surface of the flexible layer composite—that is, the side of a package made from this composite that faces away from the packaged product and towards the consumer—the base layer arrangement can have a polymer protective layer on its side facing away from the sealable barrier layer arrangement, positioned at a distance from it. This polymer protective layer, as a supplementary component of the base layer arrangement, can be extruded onto the base layer arrangement or laminated onto it as a polymer protective film with an interposition of adhesive.

[0056] To facilitate the recycling of the flexible layer composite, particularly of used packaging formed from it, the polymer protective layer is preferably a polyolefin protective layer. The general statements made above regarding polyolefin layers apply to the polyolefin protective layer as a polyolefin layer. Preferably, the polyolefin of the polyolefin protective layer and the polyolefin of the carrier polyolefin layer of the sealable barrier layer arrangement are based on the same olefin monomer. Preferably, the polyolefin of the polyolefin protective layer and the polyolefin of the polyolefin bonding layer are also based on the same olefin monomer. Preferably, the olefin monomer in question is ethylene, such that preferably at least two, and preferably all three, of the polyolefin layers—comprising the sealable carrier polyolefin layer, the polyolefin bonding layer, and the polyolefin protective layer—are each polyethylene layers.

[0057] Preferably, the flexible layer composite consists of one of the layer configurations disclosed above.

[0058] The present invention also relates to a packaging formed from the layered composite described above, in particular filled with a liquid, or even more preferably filled with a liquid foodstuff.

[0059] All information regarding the thickness or application weight of a layer or layer arrangement in the present application relates to a ready-to-use cured 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0060] - 12 -

[0061] State of the layered composite at a room temperature of 20 °C and, if in doubt, at an atmospheric pressure of 1013 hPa.

[0062] The present invention is explained in more detail below with reference to the accompanying drawings. It illustrates:

[0063] Fig. 1 shows a rough schematic cross-section through a flexible layer composite of the present application, and

[0064] Fig. 2 shows a perspective, rough schematic view of a packaging for liquid foods, made from the flexible layer composite of Fig. 1.

[0065] The figures are not to scale.

[0066] Figure 1 shows a cross-sectional schematic of a flexible layer composite discussed in the present application, generally designated by 10. The flexible layer composite 10 is suitable for packaging foodstuffs, and in particular liquid foodstuffs such as beverages, milk, cream, and the like.

[0067] A base layer 13, which determines the stability and stiffness of the flexible layer composite 10, is a fiber layer 12 with a preferred basis weight of 260 g / m². 2To protect packaged contents from radiation and to make any staining in fiber layer 12 less noticeable, fiber layer 12 is colored brown. Fiber layer 12 can be a paper or cardboard layer.

[0068] The fibrous layer 12a is printed with a multi-colored print job 14, for example in four-color printing, on its surface 12a facing the consumer and thus the consumer's external environment V, on the later packaging 80 formed from the flexible layer composite 10 (see Fig. 2). This allows consumer information such as quantity, contents, origin, and the like of the packaged product to be conveyed to the consumer. 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0069] - 13 -

[0070] A polymer protective layer 16, preferably made of LDPE, with a preferred basis weight of 10 g / m² 2 up to 20 g / m² 2, particularly preferably 14 g / m² 2 In the illustrated embodiment of Fig. 1, the polymer protective layer is extruded onto the printed layer 14. However, this is merely an example. The polymer protective layer can be formed from one or more other polymers and / or can be laminated onto the printed layer 14 as a prefabricated film with an intervening adhesive layer.

[0071] The fiber layer 12, the printed layer 14 and the polymer protective layer 16 form a base layer arrangement 18 of the flexible layer composite 10.

[0072] The surface 16a of the polymer protective layer 16, which is exposed towards the consumer-side external environment V, also forms a free surface 10a of the flexible layer composite 10.

[0073] In order to form packaging from the flexible layered composite 10, the surface 10b opposite the outer surface 10a and facing the packaged product and thus the product-side environment P on the later packaging is the exposed sealable surface 20b of a sealable polyethylene layer 20. The sealable polyethylene layer 20 preferably has a basis weight in the range of 35 g / m². 2 up to 40 g / m² 2 on, particularly preferably a basis weight of 38 g / m² 2 and thus a thickness of approximately 40 pm.

[0074] The sealable polyethylene layer 20 is produced as a pre-made polyethylene film and is provided on its surface 20a, which is not exposed in the flexible layer composite 10 and points towards the fiber layer 12, with a metallization 22, preferably made of aluminum, by physical vapor deposition.

[0075] The metallization 22 has an optical density in the range of 1 to 4. It has a thickness in the range of 5 nm to 300 nm, preferably in the range of 25 nm to 250 nm. 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0076] - 14 -

[0077] One advantage of the metallization 22 is that it is electrically conductive and can therefore be heated inductively by means of an external magnetic field via eddy currents that form within the metallization 22. Thus, the amount of heat required for heat sealing the sealable polyethylene layer 20, which preferably comprises LDPE and LLDPE, can be inductively introduced into the sealable polyethylene layer 20. Alternatively, the sealable polyethylene layer 20 can be heated conductively by external sealing tools or by ultrasound. For inductive heating of the metallization 22, its thickness is preferably in the upper half of the specified thickness range.For conventional heating by means of conductive heat transfer of the sealing tools or by means of ultrasound, the thickness can also be in the lower half of the mentioned thickness range, as long as the metallization 22 provides a sufficient barrier against the migration of oxygen and water vapor.

[0078] The sealable polyethylene layer 20, which is a carrier polyolefin layer 21 in the sense of the above introductory description, together with the metallization 22 deposited on it, forms a sealable barrier layer arrangement 24.

[0079] The sealable barrier layer arrangement 22 is connected to the base layer arrangement 12 by a polyethylene layer 26, preferably made of LDPE, which is preferably arranged as an extruded lamination layer. If necessary, the metallization 22 can be provided with an adhesion promoter layer 28 on its originally exposed surface 22a, such as an adhesion promoter layer 28 made of ethylene-acrylic acid copolymer (EAA), to increase the bond strength between the preferably extruded polyethylene bonding layer 26, preferably made of LDPE, and the metallization 22, preferably made of aluminum. Since the adhesion promoter layer 28 can only be provided optionally, it is shown in Fig. 1 only with a dashed line.

[0080] The polyethylene compound layer 26, preferably made of LDPE, has a preferred coating weight in the range of 15 g / m². 2 up to 20 g / m² 2 , particularly preferably 17 g / m² 2A preferred thickness of the polyethylene compound layer, preferably LDPE, is therefore in the range of approximately 16.5 pm to approximately 22 pm. 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0081] - 15 -

[0082] The flexible layer composite 10 is cost-effective to produce and, due to its barrier properties, offers high packaging safety for packaged products while simultaneously exhibiting excellent processability.

[0083] Fig. 2 shows a typical packaging 80 made from the flexible layer composite 10 for, for example, 1 l of milk or 1 l of fruit juice.

[0084] Packaging 80 corresponds to a typical packaging for liquid foodstuffs, as produced and filled in vertical form, fill, and seal (VFFS) packaging lines known per se. An example of such VFFS filling is shown in Fig. 6 of WO 2011 / 003565 A2, which is referenced to explain the production of the filled packaging shown in Fig. 2.

[0085] As is typical for packaging resulting from the known VFFS processes, the packaging 80 of Fig. 2 also has a transverse seal 82 on its upper surface and a longitudinal seal 84. The flexible layer composite 10 is initially formed into a tube as a web. The tube formation is achieved by the longitudinal seal 84.

[0086] A transverse seal is also present on the underside of the packaging 80, facing away from the viewer of Fig. 2. However, the tabs 88, which are also formed on the top side of the packaging 80 and attached to the side surface 86, are folded towards the underside there, so that they are not visible in Fig. 2. Due to the manufacturing process, the longitudinal seam 84 runs continuously from the upper transverse seal 82 to the lower transverse seal.

[0087] Liquid can be dispensed from the resealable packaging 80 via a screw cap 90.

[0088] Due to the fiber layer 12 and the use of only one polymer: here, polyethylene, of the same monomer, i.e., ethylene, in the polymer layers 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG

[0089] - 16 -

[0090] The packaging 80, consisting of layers 16, 26 and 20 of the layered composite 10, is environmentally friendly and can be easily recycled after use.

Claims

68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG - 17 - Claims 1. Flexible layer composite (10) for the production of packaging (80), comprising: - a baseline arrangement (18), - a barrier layer arrangement (24) comprising a carrier polymer layer (21) with a metal base layer (22) deposited thereon made of a metal-based material, - a polymer bonding layer (26) connecting the barrier layer arrangement (24) with the base layer arrangement (18) and - a sealable polyolefin layer (20), characterized in that the sealable polyolefin layer (20) is the carrier polymer layer (21), such that the barrier layer arrangement (24) is a sealable barrier layer arrangement (24), wherein the polymer compound layer (26) is a polyolefin compound layer (26) which connects the barrier layer arrangement (24) to the base layer arrangement (18).

2. Flexible layer composite (10) according to claim 1 , characterized in that the polyolefin compound layer (26) is arranged between the base layer arrangement (18) and the metal base layer (22) of the sealable barrier layer arrangement (24).

3. Flexible layer composite (10) according to claim 2, characterized in that between the base layer arrangement (18) and the metal base layer (22) of the sealable barrier layer arrangement (24) either i. only the polyolefin compound layer (26) or ii. only the polyolefin compound layer (26) with an adhesion promoter layer (28) arranged on one side of the polyolefin compound layer (26) between the polyolefin compound layer (26) and the metal base layer (22) or iii. only the polyolefin compound layer (26) with an adhesion promoter layer (28) arranged on one side of the polyolefin compound layer (26) between the polyolefin compound layer (26) and the metal base layer (22). 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG - 18 - adhesion promoter layer arranged between the dungslage (26) and the base layer arrangement (24) or iv. only the polyolefin compound layer (26) and one adhesion promoter layer each between the polyolefin compound layer (26) and the metal base layer (22) and another between the polyolefin compound layer (26) and the base layer arrangement (24).

4. Flexible layer composite (10) according to one of the preceding claims, characterized in that the polyolefin of the carrier polymer layer (21) of the sealable barrier layer arrangement (24) and the polyolefin of the polyolefin compound layer (26) are based on the same olefin monomer.

5. Flexible layer composite (10) according to claim 4, characterized in that the polyolefin of the sealable barrier layer arrangement (24) and the polyolefin of the polyolefin connecting layer (26) is polyethylene.

6. Flexible layer composite (10) according to one of the preceding claims, characterized in that the thickness of the polyolefin compound layer (26) is less than the thickness of the carrier polymer layer (21) of the sealable barrier layer arrangement (24).

7. Flexible layer composite (10) according to one of the preceding claims, characterized in that the polyolefin compound layer (26) is applied as an extruded extrusion lamination layer and / or as a dispersion.

8. Flexible layer composite (10) according to one of the preceding claims, characterized in that the polyolefin compound layer (26) has a coating weight of at least 9 g / m² 2 has been applied.

9. Flexible layer composite (10) according to one of the preceding claims, characterized in that the metal base layer (22) is a vapor-deposited metal layer (22) and / or a vapor-deposited metal oxide layer. 68644P WO Huhtamaki Flexible Packaging Germany GmbH & Co. KG - 19 - 10. Flexible layer composite (10) according to one of the preceding claims, characterized in that the thickness of the polyolefin compound layer (26) is in the range of 12 pm to 25 pm.

11. Flexible layer composite (10) according to one of the preceding claims, characterized in that the thickness of the polyolefin layer (22) of the sealable barrier layer arrangement (24) is in the range of 25 pm to 60 pm.

12. Flexible layer composite (10) according to one of the preceding claims, characterized in that the thickness of the metal base layer (22) is in the range of 5 nm to 300 nm.

13. Flexible layer composite (10) according to one of the preceding claims, characterized in that the base layer arrangement (18) comprises as base layer (13) a fiber layer (12) with cellulose and / or lignin-containing fibers.

14. Flexible layer composite (10) according to one of the preceding claims, characterized in that the base layer arrangement (18) carries a pressure layer (14) at a distance from the sealable barrier layer arrangement (24).

15. Flexible layer composite (10) according to one of the preceding claims, characterized in that the base layer arrangement (18) carries a polymer protective layer (16) at a distance from the sealable barrier layer arrangement (24).

16. Flexible layer composite (10) according to claim 15, characterized in that the polymer protective layer (16) is a polyolefin protective layer (16), wherein preferably the polyolefin of the polyolefin protective layer (16) and the polyolefin of the carrier polymer layer (21) of the sealable barrier layer arrangement (24) are based on the same olefin monomer.

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