DE102009021082A1 - Multi-layered laminate, useful for producing packing for partially dehydrated food, comprises a barrier layer arranged between a printable and/or paintable outer layer and an inner layer of polylactic acid - Google Patents

Abstract

Multi-layered laminate (10), preferably a packing laminate comprises a barrier layer (30) arranged between a printable and/or paintable outer layer (20) and an inner layer (40) of polylactic acid. Independent claims are also included for: (1) producing a multi-layered laminate, preferably a packing laminate, comprising laminating the outer layer with a barrier layer, preferably aluminum foil for producing a partially-bonded layer, and laminating the partially-bonded layer by applying a polylactic acid film on the barrier layer; and (2) a packing case, preferably tubular- or flat bag, preferably for at least partially dehydrated food, where the packing case is made up of at least one section of the laminate, preferably the packing laminate, where the longitudinal- and transverse edges of the section are sealed together by Fin-seal(RTM: Packing machine).

Description

The The invention relates to a multilayer laminate, a method for its production, its use and a product made therefrom Packaging container according to the above of the claims 1, 10, 12 and 13.

multilayer Laminates for packaging or for the manufacture of packaging Food has been known for some time. Such laminates usually consist of a paper-aluminum-polyethylene composite material, as required, a polyethylene composite layer according to the above Composite structure by a polypropylene or by a polyester layer can be replaced, the monoaxial or mostly biaxial are stretched.

When problematic in these aforementioned composite materials has become the fact that these networks are good for Packaging of soft, pasty or liquid Suitable products, but only at the cost of essential Limitations and disadvantages for bulky, edged and / or pointed products, for example for dry products like dried foods, are usable.

So There is a significant disadvantage of the aforementioned Composite materials in that this only a very low puncture resistance as well as puncture elongation and these laminates already violated at a very low penetration energy or be destroyed, so these laminates though by a replacement of polyethylene in the composite material by biaxially oriented polypropylene or such a stretched polyester in the form of one of material produced film can be improved without, however to improve the Durchstoßproblematik so that even dehydrated Foods such as dry soups, pasta, dried Onions and mushrooms or, for example, croutons are packed could pass through without any of the inside of the packaging the packaged dehydrated food initiated puncture, respectively fear a perforation of the packaging laminate to have to.

If however, such a packaging material, especially from the inside, injured, such as being punctured, inevitably results due to the associated material perforation an injury the barrier layer of the packaging material, due to a then possible oxygen, air, gas, moisture or light entry into the packaging or from the packaging to one Spoilage of the respective contents and beyond usually leads to a contamination of the same.

As mentioned above, was added according to the previous Prior art composite materials tried, the Puncture resistance of a paper-aluminum-polyethylene composite through the use of polypropylene or polyester film to improve; a satisfactory solution could, however, despite a small Increase the puncture resistance through the use of these Alternative materials in combination can not be achieved.

Thus puncture resistance of these laminates, determined by DIN EN 14477 , at the following values: composite Standard Paper * / Alu / PE Standard Paper * / Alu / PET or OPP Puncture resistance <4.0 N Puncture resistance 5.0-7.5 N Puncture strain <0.8% Penetration elongation 0.8-1.2% Piercing energy <1.6 mJ Piercing energy 3.0-5.0 mJ ^* 80 g / m ²

Of the Invention is based on the object, a laminate and its preparation and use and packaging made therefrom with the laminate being easy and inexpensive with one compared to the aforementioned prior art clearly improved puncture resistance and puncture elongation is to be prepared so that with this laminate and produced therefrom Packaging, the / an increased penetration energy in the layers is / are, in particular dehydrated Foods that have corners, points and edges, in optimized Way while maintaining the integrity of the packaging material also in used, for example, stacked state of the filled Packaging, can be packed.

This object is achieved by a multilayer laminate according to claim 1, a method for producing such a laminate according to claim 9, the use of such a laminate ge according to claim 11 and a packaging container produced from such a laminate according to claim 12.

Especially The object is achieved by a multilayer laminate, in particular Packaging laminate, preferably for packaging of at least one partially dissolved dehydrated food, taking between a, preferably printable and / or paintable outer layer and an inner layer of polylactic acid a barrier layer is arranged.

An essential point of the invention lies in the fact that polylactic acid is provided and used as a composite material, since the laminate according to the invention with such a composite layer, which is produced from a polylactic acid film, has a significantly better puncture resistance and puncture elongation compared with all the aforementioned materials Has the ability to absorb penetration energy, as set forth in the following table, so that a violation of a barrier layer, which is arranged in a use of the multi-layer laminate packaging material outside the polylactic acid-containing composite layer, is not to be feared. composite Paper / aluminum / polylactic acid Puncture resistance> 7.0 N Puncture elongation> 1.2% Piercing energy> 7.0 mJ

One Another essential point and advantage of the invention, which is from the use of a composite layer of polylactic acid results is that the composite through the use of this Polylactic acid layer high strength and rigidity receives, which has an optimized processability of the invention Polylactic acid composite brings with it, in particular the rigidity to a good machinability of the contributes to multi-layer laminate according to the invention and produced therefrom, for example, winding or folding packaging as well as packaging containers produced by sealing Furthermore, a pleasing appearance and a pleasant and high quality Haptic received.

In Advantageously, the printable and / or paintable outer layer of the laminate according to the invention consist of paper. This material is already known from the prior art and is already used as an outer layer for previous laminates used, so in an advantageous way to existing technologies for processing this outer paper layer and used for printing, respectively painting the same can be made without changes in the manufacturing process of the novel multilayer laminate would be necessary.

It It should be stressed at this point that, as desired, instead of Paper also other outer layer materials are used can, such as sealable films, which, depending on Desire to be printed in beautiful or reverse printing can to the outer layer of the invention multilayer laminate as variable and attractive to be able to shape.

When According to the invention, barrier layer materials are the following Materials and / or mixtures and / or combinations of the following Materials in question, wherein a metal, in particular aluminum foil, silicon oxide, Alumina, polyamide (PA), in particular aromatic and / or partially aromatic polyamide, ethylene vinyl alcohol copolymer (EVOH), Polyacrylonitrile (PAN) and polyethylene terephthalate (PET) are mentioned.

These The above-mentioned barrier layer materials have, alone or in combination, respectively in combination with each other optimized barrier properties in terms of a desired gas, moisture and opacity a packaging.

According to the invention the inner layer of polylactic acid in a blowing process be prepared polylactic acid film. Such in the Blown polylactic acid film is extremely inexpensive to produce and can easily with more Layers of the laminate, if desired also in one operation and also adhesive-free, if necessary.

Alternatively, the inner layer of the multilayer laminate according to the invention may also be a biaxially oriented polylactic acid film, which, for example after application of a blown polylactic acid film to further laminate layers, also by stretching this laminate layers in mono- or biaxially oriented state, each with a desired stretching ratio, in order to be able to set the properties of the multilayer laminate according to the invention with regard to its barrier effect and desired tear properties.

According to the invention, the layers of the laminate have the following thicknesses: Layer thickness [μm] preferred layer thickness [μm] particularly preferred layer thickness [μm] Outer layer ( 20 ), if made of paper 20-120 35-95 40-80 Outer layer ( 20 ), if with plastic film 5-50 8-36 12-30 Barrier layer ( 30 ) 2-18 3-12 4-10 Inner layer ( 40 ) 5-65 10-40 15-30

By a variation of these respective layer thicknesses is the invention Laminate in an advantageous manner so adaptable that it Production of small as well as large packaging containers is suitable, in particular, the respective outer layer as well as the respective inner layer with increasing packaging size adapted, for example, thicker, can be formed.

According to one Another embodiment of the invention is between Outer layer and the barrier layer and / or between the inner layer and the barrier layer a polyolefin layer, in particular a polyethylene layer and / or a polypropylene layer, preferably an LDPE layer, and / or a polyester, such as Polyethylene terephthalate, and / or arranged an adhesive layer.

ever according to the content to be packaged, the respectively required Barrier layer material and depending on this used Barrier layer material adhesion of the individual laminate layers be optimized to each other. So it is for example in the use an aluminum barrier film made possible from polylactic acid existing inner layer of the packaging laminate by means of adhesive to connect with the aluminum barrier film. Furthermore can the outer layer of the invention multilayer laminate by lamination with a polyolefin layer reinforced or sealable.

Furthermore It should be emphasized that the inner layer of polylactic acid in particularly preferably three-layer coextruded in the stent method is, by the application of the stent method and by the three-layer construction of the inner layer a particularly robust and puncture resistant inner layer of polylactic acid can be generated.

According to the invention the puncture resistance of the laminate advantageously ≥ 7.0 N, the penetration elongation of the laminate ≥ 1.2% and the puncture energy necessary for a violation of the laminate at least ≥ 7.0 mJ.

• – Laminieren der Außenschicht mit einer Barriereschicht, insbesondere Aluminiumfolie, zur Herstellung eines Halbverbundes; und
• – Kaschieren des Halbverbundes durch Aufbringen einer Polymilchsäure-Folie auf die Barriereschicht.

Furthermore, the object according to the invention is achieved by a method for producing a multilayer laminate, in particular a packaging laminate, with a barrier layer arranged between a preferably printable and / or paintable outer layer and an inner layer of polylactic acid, the following steps being carried out:

• - Laminating the outer layer with a barrier layer, in particular aluminum foil, for producing a semi-composite; and
• - Laminating of the semi-composite by applying a polylactic acid film on the barrier layer.

According to one advantageous embodiment of the invention, the outer layer made of paper, first with a polyolefin layer, in particular LDPE layer, and a barrier layer, in particular aluminum foil, extrusion-laminated, wherein the LDPE layer in the extrusion process placed directly between the paper layer and the aluminum foil to produce a modified semi-composite.

in the This is followed by the modified semi-composite by means of adhesive laminated with a polylactic acid film, wherein the adhesive as an adhesive between serving as a barrier layer Aluminum foil and the polylactic acid film is used.

Furthermore The object of the invention is also by the Use of a multilayer laminate, in particular packaging laminate, with a between a preferably printable and / or paintable Outer layer and an inner layer of polylactic acid arranged barrier layer for producing a, for example Wrapping or folded packaging or a sealed packaging container, in particular flat or tubular bag, preferably for solved at least partially dehydrated food.

A Such packaging may advantageously, for example as a wrapping or folded packaging or as a sealed packaging container, in particular flat or tubular bag, be formed, wherein a sealed packaging container of at least one blank a laminate, in particular packaging laminate, according to the above Versions is made, with each other associated Longitudinal and transverse edges of the blank with each other sealed or welded by fin-seal-sealing are.

These Fin-seal sealing is achieved by a mutual seal of respective inner layers of the invention Laminate made of polylactic acid, so that respectively facing polylactic acid layers of the invention Laminate together by sealing, respectively welding, get connected.

One particular advantage of this embodiment of the invention is that polylactic acid layers in particular more advantageous, good and tight sealed with each other can, especially then, as in the course the development of the high puncture resistant according to the invention Laminate has been found when the surfaces to be sealed by a contamination, as for example when filling of packaging and tubular bags with powdery contents occurs, contaminated, d. H. if particles of the contents on walls of a laminate forming the respective container, respectively whose sealing surfaces remain adherent.

If Such particles in packaging laminates according to the State of the art are in the sealing area, it comes in alliances with polyethylene, polypropylene and polyethylene terephthalate films as Inner layer practically inevitably leads to leaks produced sealed seam, which is why elaborate in the prior art Measures are required to each to be sealed surfaces of, in particular powdery, product residues to keep free. This is when using a polylactic acid film as the inner layer of the laminate of the invention not necessary, because such leaks due to the opposite The prior art improved sealability of the invention Laminate are not to be feared because the polylactic acid film, unlike the aforementioned films, even without the use of excessive Sealing temperature, causing damage to the laminate would result in practically their entire life Layer thickness welded together, so that in the course of the sealing process completely contaminating particles on the respective sealing layer in the sealing medium, namely the polylactic acid layer, be embedded and thus completely enclosed in the produced sealing seam are present, so that an absolute seal seam tightness guaranteed is.

Consequently is according to an advantageous embodiment the invention ensures that the fin-seal sealed inner layers at least 65%, preferably at least 80% and more preferably at least 95% of the respective inner layer thickness welded together.

Further Embodiments of the invention will become apparent from the dependent claims.

following the invention will be described by means of exemplary embodiments, which are explained in more detail with reference to the figures. Hereby show:

1 a schematic representation of a multilayer laminate according to the invention according to a first embodiment; and

2 a further embodiment of a multilayer laminate according to the invention in a schematic representation.

In The following description will be for the same and the same acting parts the same reference numerals used.

1 shows a three-layer composite of a packaging laminate according to the invention, wherein an outer layer 20 from a paper with a paper weight of 50 g / m ² to 80 g / m ² , which is printable, ge is forming. The core of the three-layer composite consists of a barrier layer 30 , This barrier layer consists of a 5 μm to 9 μm thick aluminum foil. Immediately to the barrier layer 30 borders an inner layer 40 which is a polylactic acid film having a thickness of 20 μm, which is biaxially stretched.

In 2 is a schematic representation of a second embodiment of the invention, wherein an outer layer 20 from a paper having a paper weight of 60 g / m ^{2 was} first extrusion-laminated with a sheet of low-density polyethylene (LDPE) with a grammage of 11 g. This LDPE layer is denoted by the reference numeral 50 characterized. Adjacent to the LDPE layer be there is a barrier layer 30 from a 6 μm thick aluminum foil. This semi-composite, consisting of the layer sequence paper, LDPE and aluminum, is covered with an adhesive 60 provided on which a 20 micron thick polylactic acid film, which was coextruded in three layers in the stent method applied.

In summary be mentioned that the inventive multilayer laminate due to the invention used Polylactic acid film as inner layer material opposite prior art packaging laminates has significant advantages, on the one hand in a significantly improved strength and improved Haptic and a very high puncture resistance and improved Sealable and seal-tightness are justified, while the laminate is still compared to conventional Laminates has a significantly improved elasticity and thus a higher compared to known laminates Can accommodate deformation work without one of the inventive Laminate produced packaging bursts or perforated.

Of further may be when using polylactic acid as Inner layer material in a particularly preferred manner to known Lamination and lamination techniques used Be as the properties of a polylactic acid film with which a polyethylene terephthalate film are comparable, so that the use of a polylactic acid film on conventional Plants is easily possible. Last but not least is also mentioned that polylactic acid is easily biological is degradable and thus causes significantly fewer environmental problems as usual polyethylene, polypropylene or polyethylene terephthalate containing laminates.

At It should be noted that all of the above Parts seen on their own and in any combination, in particular the details shown in the drawings, as essential to the invention be claimed. Variations thereof are those skilled in the art common.

10

laminate

20

outer layer

30

barrier layer

40

inner layer

50

polyolefin

60

adhesive layer

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited non-patent literature

• - DIN EN 14477 [0007]

Claims (15)

Multilayer laminate ( 10 ), in particular packaging laminate, preferably for packaging an at least partially dehydrated food, characterized in that between a, preferably printable and / or paintable outer layer ( 20 ) and an inner layer ( 40 ) of polylactic acid a barrier layer ( 30 ) is arranged. Multilayer laminate ( 10 ) according to claim 1, characterized in that the outer layer ( 20 ) Paper. Multilayer laminate ( 10 ) according to one of the preceding claims, characterized in that the barrier layer ( 30 ) comprises the following materials and / or mixtures and / or combinations of the following materials: metal foil, in particular aluminum foil, silicon oxide, aluminum oxide, polyamide (PA), in particular aromatic and / or partially aromatic polyamide, ethylene vinyl alcohol copolymer (EVOH), polyacrylonitrile (PAN), polyethylene terephthalate (PET). Multilayer laminate ( 10 ) according to one of the preceding claims, characterized in that the inner layer ( 40 ) is a polylactic acid film produced by the glass process. Multilayer laminate ( 10 ) according to one of the preceding claims, characterized in that the inner layer ( 40 ) is a biaxially oriented polylactic acid film. Multilayer laminate ( 10 ) according to one of the preceding claims, characterized in that the layers of the laminate ( 10 ) have the following thicknesses: Layer thickness [μm] preferred layer thickness [μm] particularly preferred layer thickness [μm] Outer layer ( 20 ), if made of paper 20-120 35-95 40-80 Outer layer ( 20 ), if with plastic foil 5-50 8-36 12-30 Barrier layer ( 30 ) 2-18 3-12 4-10 Inner layer ( 40 ) 5-65 10-40 15-30 Multilayer laminate ( 10 ) according to one of the preceding claims, characterized in that between the outer layer ( 20 ) and the barrier layer ( 30 ) and / or between the inner layer ( 40 ) and the barrier layer ( 30 ) a polyolefin layer ( 50 ), in particular a polyethylene layer and / or a polypropylene layer, preferably an LDPE layer, and / or an adhesive layer ( 60 ) is arranged. Multilayer laminate ( 10 ) according to one of the preceding claims, characterized in that the inner layer ( 40 ) is coextruded from polylactic acid in three layers by the stent method. Multilayer laminate ( 10 ) according to one of the preceding claims, characterized in that the puncture resistance of the laminate is ≥ 7.0 N, the puncture elongation of the laminate is ≥ 1.2% and the puncture energy is at least ≥ 7.0 mJ. Method for producing a multilayer laminate ( 10 ), in particular packaging laminate, according to one of the preceding claims with a between an, preferably printable and / or paintable outer layer ( 20 ) and an inner layer ( 40 ) of polylactic acid arranged barrier layer ( 30 ), wherein the following steps are carried out: laminating the outer layer ( 20 ) with a barrier layer ( 30 ), in particular aluminum foil, for producing a semi-composite; and laminating the semi-composite by applying a polylactic acid film to the barrier layer (US Pat. 30 ). Process according to claim 10, characterized in that - first an extrusion lamination of the outer layer ( 20 ) made of paper with a polyolefin layer ( 50 ), in particular LDPE layer, and a barrier layer ( 30 ), in particular aluminum foil, for producing a semi-composite; and - The half-composite is laminated by means of adhesive with a polylactic acid film. Use of a multilayer laminate ( 10 ), in particular packaging laminate, with a between an, preferably printable and / or paintable outer layer ( 20 ) and an inner layer ( 40 ) of polylactic acid arranged barrier layer ( 30 ) according to one of the preceding claims 1 to 8 for the production of a packaging, in particular tubular or flat bag, preferably for at least partially dehydrated foods. Packaging container, in particular tubular or flat bag, preferably for at least partially dehydrated food, wherein the packaging container from at least one blank of a laminate ( 10 ), in particular packaging laminate, according to one of the preceding claims 1 to 8, wherein mutually associated longitudinal and transverse edges of the blank are sealed to one another by means of fin-seal-sealing. Packaging container according to claim 13, characterized in that the fin-seal-sealing by mutual sealing of respective inner layers ( 40 ) of the laminate ( 10 ) is realized from polylactic acid. Packaging container according to one of the preceding claims 13 or 14, characterized in that the inner layers sealed by fin-seal ( 40 ) are welded together to at least 65%, preferably to at least 80% and more preferably to at least 95% of the respective inner layer thickness.