WO2012155890A1

WO2012155890A1 - Drinks container which consists largely of cellulose-containing material, and has a food-compatible barrier layer, for pressurized drinks

Info

Publication number: WO2012155890A1
Application number: PCT/DE2012/000508
Authority: WO
Inventors: Günter Keienburg
Original assignee: Keienburg Guenter
Priority date: 2011-05-17
Filing date: 2012-05-16
Publication date: 2012-11-22
Also published as: US20140339230A1; DE202011050151U1; DE112012002098A5; WO2012155890A4; EP2709844A1

Abstract

A drinks container for pressurized, in particular carbonated drinks having a lateral container surface which is closed by base and cover elements and consists of at least one parallel-wound laminate made of cellulose-containing material, preferably cardboard, and of a multilayered sheet material which is arranged in the region of the inner lateral surface of the container, and contains a barrier layer (14), has, in the region of the lateral container surface, an overlapping peripheral strip with a width of overlap of from 5 to 25 mm, wherein the laminate, at least in the region of the overlapping peripheral strip, is coated, preferably on both sides, with an adhesive sheet material, preferably based on PE, in particular HDPE, and/or has the same wound around its outside, wherein the overlapping peripheral strips of laminate are connected to one another by ultrasonic welding. The overlapping peripheral strip has a first, striplike portion, which extends over the entire height of the lateral container surface, and a second portion, which follows the first portion in symmetrical fashion and is curved convexly outwards in the circumferential direction of the container.

Description

Beverage can, made largely of pulp-containing material and having a food-grade barrier layer, for over-pressure drinks

The invention relates to a beverage can according to the preamble of claim 1 for standing under pressure, especially carbonic acid containing drinks with a sealed by bottom and lid elements can jacket, the at least one parallel wound layer of pulp-containing material, preferably cardboard, and at least one liquid-tight, food-compatible barrier or barrier layer.

Such beverage cans are known and described, for example, in US 2004/0052987 A1, WO 03/006237, JP 2005-239230 A and EP 08 013 126.

It has been found that the prior art beverage cans do not have a sufficiently high barrier or barrier effect against water, water vapor, oxygen and carbon dioxide and also not in particular in the region of its lateral surface in

CONFIRMATION COPY are able to withstand the internal pressures acting on them over a long period, as they occur especially in beer cans.

The invention has for its object to provide a beverage can according to the preamble of claim 1, which is capable, in particular in the region of the lateral surface to withstand it acting high pressure forces.

To solve this problem is a beverage can with the features of the characterizing part of claim 1.

It has been found that by ultrasound welding, preferably by means of a sonotrode, a beverage can which also withstands high internal pressures is obtained.

According to a preferred embodiment of the invention, it is proposed that the overlapping area has a first strip-shaped section which extends over the entire can jacket height and has a width of 8 to 15 mm, preferably 9 to 12 mm, and a first strip Section has symmetrical subsequent second, in the circumferential direction of the box convexly outwardly curved portion. Through this "bulge" optimal distribution of the forces acting on the can jacket forces, in particular tensile forces is achieved.

According to a preferred embodiment of the invention, it is provided that the convex portion is bevelled at its ends towards the upper and lower lid shroud edges in the direction of the first strip-shaped portion in order to ensure maximum strength and safety in the region of the transition points between the can jacket and the can bottom or to reach the can lid.

In order to obtain a beverage can having a high barrier effect against water, water vapor, oxygen and carbon dioxide, it is provided according to a preferred embodiment that the multilayer film (ΠΙ) has a total thickness between 50 μm and 120 μm, preferably between 80 and 100 μm, and the thickness proportion of the layer (14), based on the total thickness of the multilayer film (III) between 5% and 15%, preferably between 8% and 12%, and that the layer (14) on both sides of the entire surface between polyolefin layers, preferably PE layers , is embedded. Further preferred embodiments of the invention are dealt with in subclaims 8 to 20.

It has been found that a satisfactory solution of the pending problems in beverage cans of the type according to the invention is achieved only with the inventively proposed thicknesses and grammages of the individual layer.

Preferably, at least one metal foil is integrated into the can jacket.

The invention will be described in more detail below with reference to the drawings:

Figure 1 shows a prior art beverage can, the can jacket consists of at least one parallel wound laminate of pulp-containing material;

Figure 2 shows an exploded view of a beverage can with the present invention designed overlap area for connecting superimposed

Laminate sections;

FIG. 3 shows a development of the can jacket;

Figure 4 shows a simplified representation of a cross section of the laminate used in particular for the can jacket;

FIG. 5 shows the layer structure of a multilayer film (multi-layer layer) which faces the can interior and forms a barrier layer;

FIG. 6 shows, in a simplified perspective view and on a greatly enlarged scale, the layer structure of the laminate used in particular for the can jacket;

FIG. 1 shows a beverage can 1 which can be assembled from at least one parallel-wound laminate of cellulose-containing material, preferably cardboard, a lid 2 and a bottom 3, the lid 2 and the bottom 3 preferably being made of the same laminate material as the can jacket 1.

The laminate I contains a cardboard layer II comprising a plurality of cardboard layers, a multilayer film III forming a barrier layer and a barrier layer, an outer PE or PE / PA or LDPE coating W and an adhesive layer V. The outer coating IV, which corresponds to the outer layer 5 in FIG. 6, has a weight per unit area of 13 to 50 g / m ² , preferably 20 to 40 g / m ² , in particular 40 g / m ² .

The total thickness of the laminate I according to the invention is 0.5 to 0.8 mm, preferably 0.5 to 0.7 mm, preferably 0.58 to 0.63 mm, in particular 0.61 mm, the total thickness of the multilayer film III 50 to 120th μπι, preferably 80 to 100 μπι, is.

The multilayer film III has, as shown in Figure 5, the following structure:

- Inner and outer layers 11 and 16 of a sealable polyolefin, a copolymer of a sealable polyolefin or mixtures of these substances, in particular PE, preferably HDPE; the proportion of these polyolefin layers 11 and 16, based on the total thickness of the multilayer film III, is between 30 and 80%, preferably between 50 and 75%;

- At least one layer 12 of a polymer of the group polyester, polyamide or polypropylene, preferably polyamide. The proportion of this layer (s), based on the total thickness of the multilayer film III, is between 8 and 25%, preferably between 10 and 18%. This layer is responsible for the strength of the multilayer film and also provides sufficient elasticity and stability.

- At least one polymeric barrier layer 14, consisting of EVOH, polyamide or polyvinylidene chloride, preferably EVOH, with a proportion of this layer, based on the total thickness of the multilayer film, between 5 and 15%, preferably between 8 and 12%.

- Also effective as adhesive layers 13 and 15 layers of PE, HDPE or LDPE.

The actual blocking and barrier layer 14, preferably made of EVOH, must be embedded on both sides without gaps between the layers 13 and 15 in order to obtain the effect of the barrier layer for a longer period of time.

According to FIG. 6, the cardboard layer II contains several, preferably four cardboard layers 4, which preferably consist of bleached and / or unbleached sulphate paper or kraft paper. These cardboard layers 4 each preferably have a grammage of between 80 and 120 g / m ² , preferably between 95 and 105 g / m ² . To increase the strength of the beverage can according to a preferred embodiment of the invention between two layers 4 made of cardboard, a metal foil, preferably a stainless steel or aluminum foil inserted or glued, which preferably has a thickness between 15 to 20 microns.

The layers 6, 7 and 8 have in particular the functions of adhesive layers and consist of polyolefins, preferably PE, HDPE, LIDPE and the like, with a grammage in the range of 13 to 17 g / m ² , preferably 15 g / m ² .

The layer 6 may preferably also consist of polyethylene terephthalate (PET) with a gram weight of 13 to 17 g / m, preferably 15 g / m.

The layer 8 may preferably also consist of PA PE with a grammage in the range of 18 to 22 g / m, preferably 20 g / m. This layer 8 can also be a composite layer of a PA PE Surlyn foil with a grammage of between 18 and 27 g / m, preferably 25 g / m ² .

The multilayer film III is preferably produced by coextrusion by blow molding, coextrusion in the casting process or by adhesive-based lamination of two or more individual layers, which in turn are preferably themselves co-extruded.

Beverage cans with a filling volume of e.g. 3 to 15 liters or more are preferably made of multi-layer wound laminate I.

The overlap width of the laminate in the area of the can jacket and thus the width of the adhesive strip is advantageously in the range of 5 to 25 mm, preferably in the range of 10 to 15 mm.

In order to protect the outer edges of the cardboard layers 4 against the ingress of moisture, the laminate in the region of the edge strips is preferably coated or wrapped on both sides with a sealing film, preferably adhesive film based on PE, in particular HDPE. The overlapping edge strips of the laminate are preferably joined together by ultrasonic welding, for example by means of a sonotrode or by heat bonding.

Preferably, the laminate edges are sealed with a sealing seam covering in particular the cardboard layers, which consists in particular of PE, preferably HDPE.

Referring to Figs. 2 and 3, an overlapping area is provided for joining the can sheath ends, having a first strip-shaped portion 20 extending over the entire can sheath height and having a width of 8 to 15 mm, preferably 9 to 12 mm, and adjacent thereto first section 20 has symmetrical subsequent, circumferentially convexly outwardly curved portion 21. The second section 21 is circular arc-shaped with a radius R, which, based on the height H of the can jacket between R = 0.85 H and R = 0.93 H.

The convex portion 21 is preferably chamfered at its ends toward the first portion 20.

The overlap area has a corrugated structure created by press stamping, which can improve the bond between the two laminate layers in the overlap area.

The arcuate shape of the convex portion 21 may also follow an elliptical line in a further embodiment of the invention.

Claims

claims

1. beverage can for pressurized, especially carbonated beverages containing a sealed by bottom and lid elements can jacket consisting of at least one parallel wound laminate of pulp-containing material, preferably cardboard, and arranged in the region of the inner circumferential surface, multilayer film, which is a barrier and / or barrier layer (14), characterized in that in the area of the can jacket the overlapping width of the laminate is in the range of 5 to 25 mm, preferably in the range of 10 to 15 mm, and in that the laminate is at least in the region of the overlap Edge strips preferably on both sides with an adhesive film, preferably on the basis of PE, in particular HDPE, coated or wrapped on the outside, and that the overlapping edge strips of the laminate are joined together by ultrasonic welding.

2. beverage can for pressurized, especially carbonic acid-containing drinks with a sealed by bottom and cover elements can jacket, which consists of at least one parallel wound laminate of pulp-containing material, preferably cardboard, and arranged in the region of the inner surface, multi-layer film, which is a barrier - or barrier layer (14), characterized in that in the area of the can jacket, the overlap width of the laminate in the range of 5 to 25 mm, preferably in the range of 10 to 15 mm, and that the laminate at least in the region of the overlap edge strips preferably on both sides with an adhesive film, preferably based on PE, in particular HDPE, coated or wrapped on the outside, and that the overlapping edge strips of the laminate are joined together by heat bonding.

3. beverage can according to claim 1 or 2, characterized in that the overlap region a

- First strip-shaped portion (20) which extends over the entire can jacket height and has a width of 8 to 15 mm, preferably 9 to 12 mm, and a has at this first portion (20) symmetrically adjoining, in the circumferential direction convexly outwardly curved portion (21).

4. beverage can according to claim 3, characterized in that the second portion (21) is designed in a circular arc with a radius (R), based on the height (H) of the can jacket between R = 0.85 H and R = 0, 93 H is.

5. beverage can according to claim 3 or 4, characterized in that the convexly curved second portion (21) is bevelled at its ends to the upper and lower edges of the can jacket in the direction of the first portion (20).

6. beverage can according to one of claims 3 to 5, characterized in that it has a corrugated structure produced by pressing in the region of the overlap region.

7. beverage can according to one of claims 1 to 6, characterized in that the multilayer film (ΠΙ) has a total thickness between 50 μπι and 120 μπι, preferably between 80 and 100 μπι, and that the thickness proportion of the layer (14), based on the total thickness of the multilayer film (III) is between 5% and 15%, preferably between 8% and 12%, and that the layer (14) is embedded on both sides over the entire surface between polyolefin layers, preferably PE layers.

8. beverage can according to one of claims 1 to 7, characterized in that at least one metal foil is integrated into the can jacket.

9. beverage can according to one of claims 1 to 8, characterized in that the can jacket contains a plurality of layers (4) made of cardboard, and that a metal foil between two layers (4) is inserted

10. beverage can according to claim 3, characterized in that the metal foil is a stainless steel or aluminum foil with a thickness between 15 to 20 μπι.

11. beverage can according to any one of claims 1 to 10, characterized in that the layer (14) consists of a material selected from the group of EVOH, Polyamide or polyvinylidene chloride, preferably of EVOH having a weight in the range of 15 to 25 g / m ² , preferably 19 to 21 g / m ² .

12. beverage can according to one of claims 1 to 1 1, characterized in that the multi-layer film (III) on its inner and outer sides each having one or more layers (11 or 16) of HDPE, and that the proportion of this layer (s ) (11 or 16), based on the total thickness of the multilayer film (III), between 30% and 80%, preferably between 50% and 75%.

13. beverage can according to one of claims 1 to 12, characterized in that the multilayer film (ΠΙ) at least one layer (12) of a polymer from the group polyester, polypropylene or preferably PA contains, and that the proportion of this layer (s) ( 12), based on the total thickness of the film, between 8% and 25%, preferably between 10% and 18%.

14 beverage can according to one of claims 1 to 13, characterized in that the multi-layer film in the direction of the inner wall to the outer wall of the can jacket has the following structure:

an inner HDPE layer (16);

- ^" a PE layer (15);

an EVOH layer (14);

a PE layer (13);

a PA layer (12) and

- An outer HDPE layer (1 1).

15. beverage can according to one of claims 1 to 14, characterized in that the EVOH layer (7) is embedded between a PE layer (15) having a weight in the range of 12 - 18 g / m ² , preferably 14 - 16 g / m ² , and a PA / PE Surlyn layer weighing between 3 - 6 g / m ² .

16. beverage can according to one of claims 1 to 15, characterized in that the can jacket a plurality of layers (4) made of cardboard, in particular bleached and / or unbleached sulphate board, having a total weight in the order of 300 - 450 g / m ² , preferably 350 - 420 g / m ² , comprising.

17. beverage can according to one of claims 1 to 16, characterized in that the can jacket four cardboard layers each having a basis weight of 75 - 125 g / m ² , and that between the cardboard layers and between the cardboard layers and the metal foil (10) adhesive layers the basis of

grammage

- PA / PE 19-21 g / m ² ,

or

- LIDPE 14 - 16 g / m ² ,

or

- PET 13 - 17 g / m ^{2 are} provided.

18. beverage can according to one of claims 1 to 17, characterized by a laminated on the outer cardboard layer of the can jacket PE or LDPE coating having a basis weight of 13 - 50 g / m ² , preferably 20 - 40 g / m ^2, in particular 40 gm ² .

19. beverage can according to one of claims 1 to 18, characterized in that at least one cardboard layer consists of Kraft or sulfate paper.

20. beverage can according to one of claims 1 to 19, characterized in that the cardboard layers and the multilayer film (ΙΠ) existing laminate is wound at least two days.