NZ614844B2 - Improved composite system for packaging - Google Patents

Abstract

multi-layer laminate for producing food packaging comprises a paper layer and a barrier layer. The laminate does not comprise any metal foil. The barrier layer comprises a biodegradable material, and comprises a carrier layer and a vapour-deposited barrier material layer. The carrier layer consists of polylactic acid materials or cellophane, and the barrier material layer consists of vapour-deposited (semi)metal oxides. s of polylactic acid materials or cellophane, and the barrier material layer consists of vapour-deposited (semi)metal oxides.

Description

Improved composite system for packaging The present invention relates to a multilayer composite system, suited for the manufacture of foil packaging, for example for food. The multilayer composite system is in particular suited for the manufacture of up pouches which are suited for the packaging of liquid food, in particular beverages.

Prior art Food systems assembled from composite systems, in particular stand-up pouches or block bottom pouches, are well-known. Typical composite systems for such stand—up pouches are y adhesive laminated and/or extrusion laminated or coated, respectively, in particular ic foils being present as barrier layer carrier or as layer for ing mechanical properties. Further layers of such laminates are plastic layers which can have different designs depending on their intended application. Here, the employment of als which are prepared on the basis of petroleum and/or which are not biodegradable or compostable have been typical to date.

Such composite systems as well as stand—up s and manufacturing processes for stand— up pouches or other packaging systems are known from prior art, for example from EP 2 223 866 A1, , or EP 0 600 502. The composite systems disclosed therein are not radable, so that packaging manufactured from them can only be disposed of in a conventional manner, while disposal by composting is not possible. At the same time, these composite systems employ starting substances that have been manufactured using high s of energy, such as metal foils, and they moreover consume petroleum-based materials.

However, it is, in particular also in the field of food, desired to rather switch to eco—compatible materials and in particular to do without metal foils (as these are manufactured using high amounts of energy and other resources, such as . Compostability would er open a simple way of disposal as such laminates and packaging can then be simply correspondingly reused by way of the meanwhile wide-spread waste al systems. The application of (followed by page 2a) materials on the basis of renewable resources would moreover not strain the existing resources of petroleum and also contribute to improve the carbon footprint.

A1, WO 96/31303 A1, DE 011641 U1, JP 2010069766 A, CN 2457074, and disclose packaging als.

Obiect of the t invention 80, it is the object of the present invention to provide a composite system, in ular suited for the manufacture of a up pouch, wherein the composite system comprises the required properties for the manufacture of such food packaging, such as stability, ess to liquids, gas passage, etc., wherein eco-compatible or biodegradable materials should be employed to the greatest possible extent, and/or to at least provide the public with a useful choice.

Brief description of the invention This object is ed by a composite system according to claim 1. Preferred embodiments of this composite system are given in subclaims 2 to 9 and in the following description.

Furthermore, the present invention also provides a food packaging comprising the composite system according to one of Claims 1 to 9. This food packaging is preferably a stand—up pouch.

In accordance with a first aspect of the invention, there is provided a composite system suited for the manufacture of food ing, comprising a paper layer and a barrier layer, wherein the composite system does not comprise any metal foil, and wherein the barrier layer comprises a biodegradable material, wherein the barrier layer comprises a carrier layer and a vapor— ted barrier material layer, wherein the carrier layer consists of polylactic acid materials or cellophane, and the barrier material layer consists of vapor—deposited (semi)metal oxides.

The term ‘Comprising’ as used in this specification and claims means ‘consisting at least in part of’. When interpreting statements in this ication and claims which include the term ‘comprising’, other features s the features prefaced by this term in each statement can also be present. Related terms such as ‘comprise’ and ‘comprised’ are to be interpreted in similar .

In accordance with a second aspect of the ion, there is provided food packaging, comprising the composite system of the first aspect described above. (followed by page 3) ed description of the invention The composite system in accordance with the t invention comprises, as an essential ent, a layer of paper and at least one r layer, and is characterized in that the composite system does not comprise any metal foil.

Further embodiments of the composite system according to the invention and advantages in connection with it are listed below. The additional layers defined below, preferred employed layer materials, layer thicknesses and further embodiments can be each combined with each other as desired; the specific layer sequences of the composite system according to the invention given below serve to describe and illustrate the present invention, which, however, is not restricted to such specific examples.

Paper layer: The composite system in accordance with the present invention comprises, as an essential layer, a paper layer. This paper layer typically has a thickness within a range of 150 to 15 um, preferably 100 to 25 pm, in particular red 80 to 30 um, such as for example 35, 45 or 50 pm. According to the invention, any types of paper can be used, including papers with s, such as kaolin, talc, titanium dioxide, starch, calcium carbonate, etc. The paper to be employed according to the ion can be an uncoated or coated paper, papers with very short fibers being preferred. ularly preferred are arent papers, e.g. pergamyne paper, a paper manufactured from finished pulp.

The essential paper layer according to the invention is typically present in the final food packaging relatively far on the side of the composite system facing outwards, and the paper layer to be used according to the invention, in particular the red paper layer of pergamyne paper, in particular contributes to the mechanical strength and stiffness of the composite system of the present invention. The preferred use of pergamyne paper furthermore leads, due to the transparency of this paper, to various types of printing being possible since reverse printing methods, where the interior side of the pergamyne paper layer is printed, are for example possible (the printout then shows through to the outside, so that in particular any damage and abrasion at the printing on the outer surface of the paper layer can be d). The paper material of this layer can furthermore be equipped with additional additives, such as absorbers, etc. Thus, the contribution of this layer to the l properties of the composite system can be optimized. er, the use of paper layers permits a contribution to climate protection, since for the manufacture of the paper, ing the yne paper, renewable resources are employed, so that here an improvement of the carbon footprint is altogether permitted.

Barrier layer: Furthermore, the ite system in accordance with the present invention comprises at least one barrier layer. Depending on the desired embodiment of the composite system, several options are possible here with respect to the type of barrier layer, the position of the barrier layer in the composite system and also with respect to the number of barrier layers. The composite system of the present invention can comprise one or several barrier , such as one, two or three barrier layers. These can differ with respect to their type and position in the composite system. The barrier layer can be, for example, a barrier material layer and/or a sealing layer with a barrier property, and/or a lacquer layer, which will each be bed below." Barrier material layer: The first option is the provision of a r material layer on the side of the above described paper layer located inside in the food packaging. Such a barrier material layer in accordance with the present invention preferably ses a carrier layer with a preferably vapor-deposited layer of a barrier material. As an alternative, it is also possible to apply the layer of barrier material as a lacquer as will be described further below. Here, the carrier layer accounts for the major part of the r because the preferably vapor-deposited layer of r material itself only comprises a few om, and the alternatively provided coat of r is also clearly thinner than the carrier layer. As principal component, the carrier layer preferably comprises a material which is biodegradable and/or made of renewable resources. Materials ularly suited as carrier layer for the barrier material layer to be used according to the invention are ctic acid materials and cellophane. Polylactic acid materials are already being used for foil materials and packaging, for example as mulch film or for shopping bags. Other known fields of application of polylactic acids are disposable cutlery, straws and boxes with screw caps. Another preferred material for the barrier layer is cellophane, a material also known under the designation regenerated cellulose.

The preferred materials for the carrier layers of the barrier material layer of the present invention y comprise certain barrier fitness, in particular s liquids. These r carrier layers typically have a thickness of about 10 to 100 pm, preferably 12 to 50 pm, in particular preferred to 40 pm, such as for example 25 um.

However, to ensure the desired barrier ty, it is necessary to provide the above d carrier layer with a layer of barrier material. According to the invention, in particular vapordeposited barrier materials are here employed because in this way, a desired barrier effect, in particular towards oxygen, C02, but also towards water vapor can be ensured with a very thin layer (only a few angstrom). r materials suited ing to the invention are vapor- ted layers of (semi)metal oxides or (semi)metals, for example aluminum, SiOg, Al203, or other oxides and mixed oxides or mixtures. Here, the oxide materials are preferred as one can thus altogether do without a metal layer.

The vapor-deposited layer of the barrier material is preferably applied on one side of the carrier layer, however, it is also possible to apply this vapor-deposited barrier on both sides of the carrier layer. Preferably, the barrier, as it is defined above, comprising the carrier layer and the vapor-deposited layer of barrier material, is disposed in the composite system according to the ion such that the vapor—deposited barrier is t on the side of the carrier layer facing away from the paper layer. However, other embodiments are also possible. Often an arrangement is selected based on deliberations with respect to the cturing process (that means the sequence of the application/introduction of the individual layers of the composite system) which s that the barrier material is covered by a further layer as quickly as possible to protect this relatively sensitive layer from damages in the further manufacturing process.

According to the invention, it is red to apply the above defined r material layer onto the paper layer described in the beginning. Here, common layers improving adhesion can be applied n them and typically have a thickness of less than 20 pm, in particular preferred is a thickness of 1 to 10 pm, in particular preferred 2 to 5 um. Suited materials and types of application for such layers are well—known to the person skilled in the art, and suited examples are adhesive layers (extrusion glue, lamination adhesive, etc.). Here it is again preferred for the materials for such adhesive layers to be biodegradable and/or based on renewable resources.

The preferred materials for the carrier layer mentioned above, such as lactic acid materials and cellophane, furthermore permit, due to their smooth surface obtained in film manufacture, the vapor-deposition of very thin layers of barrier material as no major compensation for a rough surface of the carrier layer must be created here. At the same time, the above described barrier materials adhere well to the carrier layer, so that a secure fabrication of the barrier layer comprising the carrier layer and the vapor—deposited layer of barrier materials is ensured.

Apart from its barrier effect, this r layer also contributes to mechanical strength, but also to tection. By the use of fillers and additives, these properties can be further modified and optimized, wherein common materials known to the person skilled in the art are ed, for example, as UV—absorbers or fillers to increase stiffness.

Another option of a barrier layer is a correspondingly ed sealing layer which will be described below.

Sealing layer: The composite system in accordance with the present invention furthermore comprises a sealing layer which is applied onto one side of the above described barrier material layer. This sealing layer is disposed such that it is the innermost layer among the ial layers of the composite system, i.e. the sealing layer is lly directly the inner layer of a finished food packaging. The sealing layer in accordance with the present invention is also preferably manufactured from biodegradable or preferably even compostable materials and/or from materials based on renewable resources. ln particular polymer als on the basis of polyesters, for example the polylactic acid materials already described above, but also PBAT (polybutylen—adipate-terephthalate) and other, similar materials as well as es of them are preferred. For example, a material commercially available from BASF under the designation Ecoflex® is suited.

The sealing layer preferably has a thickness of about 10 to 200 pm, ably 20 to 150 pm, in particular preferred 100 to 50 um, such as for example 90, 75 or 60 um.

The sealing layer can also be again provided with additives and fillers, as is described above for the other layers. Again, the properties of the composite system can be modified and optimized by them.

To securely apply this sealing layer onto the above described r layer, an adhesion- improving layer can be used again which is designed as already described above. To further improve adhesion, onal techniques for the improvement of the on of the individual layers can be employed, such as surface treatments by flaming s or corona discharge, etc.

Furthermore, the above bed sealing layer can also be coated, preferably vapor—deposited, with barrier materials. For this, the materials already described above can be employed; ularly preferred are here again oxidic coatings, in particular SiOX, AlOX, mixtures of them and other oxides. Such barriers can also be again applied onto one or both surfaces of the sealing layer, the application onto one surface often being sufficient in particular also for cost reasons. If the sealing layer described herein comprises such a barrier layer, it is in some embodiments of the present invention possible to dispense with the above described r al layer as in this embodiment, the sealing layer then assumes the barrier effect, so that a layer structure with a paper layer and a sealing layer provided on it is possible, while sufficient barrier properties and mechanical properties of the total composite system are still achieved. By the use of the above described polyester materials, it is again ensured that the composite s of the present invention essentially consist of materials which are at least biodegradable or preferably compostable, respectively.

Another option of a barrier layer is a coat of r which will be described below Coat of lacquer Another option for a r layer is a coat of lacquer which can be applied, for e, onto the paper layer. Suited examples of coats of lacquer are lacquers based on ose nitrate. These can serve, for e, as moisture barrier. Suited ways of application, layer thicknesses and materials for such layers are known to the person skilled in the art.

Adhesive layers If required, adhesive layers can be provided between the here described layers for improving adhesion, wherein common adhesive materials known to the person skilled in the art can be employed, for example the extrusion glue and lamination adhesive already discussed above.

Suited materials are known to the person skilled in the art and at this point, too, it should be mentioned again that it is preferred for the materials for such adhesive layers to be biodegradable and/or based on renewable resources. Such adhesive layers are preferably employed between the paper layer and the barrier layer, in particular between a paper layer and a r layer which is part of an above defined barrier material layer. Furthermore, adhesive layers are preferably provided between the sealing layer and the barrier layer, where it is again a preferred embodiment to provide such an adhesive layer between the sealing layer and the carrier layer of the barrier material layer. However, it is also an option to provide an adhesive layer between the paper layer and the barrier layer or the sealing layer and the r layer, such that this adhesive layer is provided in contact with the layer of r material. Such adhesive layers improve the adhesion of the individual layers of the composite system, but they can additionally also contribute to barrier properties, in particular against oxygen permeation.

Shellac layer Another option is the provision of additional shellac layers which essentially consist of shellac.

Such shellac layers can be provided at any position in the ite system, and these layers preferably have a comparably small thickness which is typically less than 20 pm, ably about 1 to 10 um, particularly preferred 2 to 5 pm.

Such shellac layers can be ed between the paper layer and the barrier layer, between the barrier layer and the sealing layer, or else between the carrier layer and the layer of barrier al. One or l layers of c can be provided to thus further improve the barrier effect of the composite material according to the invention.

The options for barrier layers described herein can be employed individually, but also in combination in the composite system according to the invention, depending on the d application. The number of these layers can be arbitrarily selected, and for e one, two or three barrier layers which can be the same or different can be present.

The present invention altogether provides an improved composite system suited for the manufacture of food packaging, in particular stand-up pouches, wherein one can dispense with metal foils without any disadvantageous effect on the barrier properties and mechanical ties, and essentially polymer materials based on renewable resources and/or radable polymer materials are employed.

Apart from the above described essential layers and the optional layers improving adhesion, the composite system of the present invention can se onal layers, for example a lacquer on the outer surface of the paper layer or another sealing layer on the inner and/or outer surface of the composite system.

So, exemplary composite systems can be ured as follows (from the outside to the inside, in on to a food packaging): r/paper layer/adhesive/barrier material layer/adhesive/sealing layer lacquer/paper layer/adhesive/barrier material layer/adhesive/sealing layer with barrier material lacquer/paper layer/adhesive/sealing layer with barrier material paper layer/adhesive/barrier material layer/adhesive/sealing layer lacquer/paper layer/barrier material layer/sealing layer However, the present invention is not cted to these exemplary embodiments.

The composite system in ance with the present invention is in particular suited for the manufacture of food packaging, in particular for liquid or semiliquid food, preferably beverages, in particular fruit juices and other fruit containing beverages. The composite system ing to the invention in particular permits to manufacture a up pouch by conventional manufacturing processes, so that food packaging can be provided which are essentially based on biodegradable raw materials and can be, for example, completely composted for disposal.

Claims (13)

WHAT WE CLAIM IS:

1. Composite system suited for the manufacture of food packaging, comprising a paper layer and a barrier layer, wherein the composite system does not comprise any metal foil, and wherein the barrier layer ses a biodegradable material, wherein the barrier layer comprises a carrier layer and a vapor-deposited barrier material layer, wherein the r layer consists of ctlc acid materials or cellophane, and the barrier material layer consists of vapor-deposited (semi)metal oxides.

2. Composite system according to claim 1, characterized in that the paper layer ts of transparent paper.

3. Composite system according to claim 1 or claim 2, terized in that the paper layer comprises a thickness of 10 to 100 pm.

4. Composite system according to any one of the preceding claims, characterized in that a sealing layer is furthermore present.

5. Composite system according to claim 4, characterized in that the barrier layer is d onto the paper layer and the sealing layer is applied onto the opposite surface of the barrier layen

6. Composite system according to any one of claims 4 to 5, characterized in that the sealing layer comprises a vapor-deposited barrier material layer.

7. Composite system according to any one of claims 4 to 6, characterized in that between the paper layer and the barrier layer and/or between the barrier layer and the sealing layer, a layer ing adhesion is provided.

8. Composite system according to any one of the preceding claims, characterized in that one, two or three barrier layers are present.

9. Composite system according to any one of the preceding claims, characterized in that compostable materials are contained, and that the ite system is compostable.

10. Food packaging, sing the composite system ing to any one of claims 1 to 9.

11. Food packaging according to claim 10, characterized in that it is a stand—up pouch.

12. Composite system according to claim 1, substantially as herein described with reference to any embodiment disclosed.

13. Food packaging according to claim 11, substantially as herein bed with reference to any embodiment disclosed.