can

Abstract

The present invention relates to a can for containing a solid, liquid and / or gaseous medium that may have an overpressure or that may develop an overpressure during transportation or storage, the can having a cylindrical can sleeve (101) of which consists mainly of a paper or cardboard material and which comprises at least two wound layers, which is closed at the bottom by a base element (4) and at the top by a lid element (5), the innermost layer of the can sleeve (101) consisting of a straight wound barrier layer (102) having a longitudinal seam running in the longitudinal direction of the can (1), whereby The opening is sealed on the inside by a film sheet of a barrier layer (102) which once overlaps the barrier layer (102) in the area of ​​the longitudinal seam, or the longitudinal seam is sealed by a sealing strip (110) running straight in the longitudinal direction of the can, or the longitudinal seam forms an increased thickness and the inner or outer longitudinal edge of a further layer (103, 104) of the can sleeve (101) in the form of a rolled layer of paper or cardboard material faces the side of the increased thickness.

Description

[Technical field]

[0001] The present invention relates to a pressure can having a can shell made of a composite material. [Background technology]

[0002] A pressure canister is a canister for packaging media that have positive pressure or that may generate positive pressure during storage, transportation, or use.

[0003] The invention therefore relates to a fluid container, in particular a beverage container, which can also be used for gas-releasing canned beverages, such as carbonated mineral water, sweet drinks, energy drinks or beer, because, as a special feature, it is sufficiently resistant to pressure for these purposes. Depending on the design, it is also suitable for all kinds of spray cans with even higher internal pressures. Furthermore, the invention relates to a technical manufacturing and logistics method, whereby the use of such a beverage can facilitates the filling of beverages, in particular the filling of cans on-site, which can be produced, if necessary, preferably in synchronism with existing filling plants. Preferably, conventional can fillers who are adapted to the introduction of this new fluid or beverage container do not have to adapt their can filling plants and can continue to use them seamlessly. In-house production of cans is facilitated, which requires only a small fraction of the space required for the previously essential buffer storage of empty aluminum cans for further filling.

[0004] In the packaging industry, multi-layer packages are known that have a paper or cardboard packaging material, the individual plies of which are wound linearly or obliquely relative to the longitudinal direction of the mandrel, and therefore have a joint area with themselves that runs in the longitudinal direction of the packaging shell or that runs spirally around the longitudinal direction of the packaging shell. These packages may also have an inner barrier layer, the joint areas of which at the two edges have tightly folded seams. As a composite of layers, cardboard and paper materials are generally used. Such can shells have been used so far for general packaging purposes, for example for packaging powders such as detergents, cocoa powder, or snacks such as potato chips, in the case of food products, the barrier layer protects the food product against the ingress of liquids and gases from the outside and prevents the escape of liquids and gases from the food product or from the inside of the packaging shell.

[0005] On the other hand, there are many composite packages with can shells made of composite materials for food and beverages. However, these have reached their limits in the field of compressive strength and therefore have not been used for pressurized media, especially carbonated beverages. There are proposals in the patent literature, for example WO 9959882 A9 and EP 0101139 A2, for such can shells made of composite materials for carbonated beverages, but so far no such products have been on the market. Perhaps because the proposed can shells and / or finished cans could not achieve sufficient compressive strength or because these proposed can shells and / or finished cans could not compete with conventional beverage cans, especially aluminum cans.

[0006] A disadvantage of the package for carbonated drinks described in WO 9959882 A9 is its particular shape, which on the one hand requires a unique filling and sealing device and, on the other hand, deviates from the shape of a drink can familiar to consumers.

[0007] A disadvantage of the carbonated drink package described in EP 0101139 A2 is its special shape, which, on the one hand, requires a unique filling and sealing device and, on the other hand, deviates from the shape of a drink can to which consumers are accustomed, especially in the area of ​​the base and the lid.

[0008] From DE 202007010192(U1) a composite can for carbonated drinks is known, the shell of which consists mainly of paper or cardboard material and has a wall thickness of 0.5545 mm. A disadvantage of DE 202007010192(U1) is that the shell consists of thick sulfate boards that are coated on both sides and overlap each other, resulting in areas that are very wide compared to the rest of the shell. Another disadvantage is that the side edges of the inner and outer edges of the laminate are exposed and therefore need to be further sealed, for example with tape.

[0009] WO2012155890A1 describes a carbonated beverage package having a shell made of a composite material, the shell consisting mainly of paper or cardboard material. The composite shell of the can has a shell thickness (or layer thickness) of 0.5-0.8 mm and a barrier film thickness of 50-120 μm. A disadvantage of WO2012155890A1 is that the entire laminate overlaps, resulting in a very wide section compared to the rest of the shell. Another disadvantage is that the side edges of the inner and outer edges of the laminate are exposed and therefore need to be further sealed, for example with tape.

[0010] From US Pat. No. 3,687,351 A1 a composite can for carbonated drinks is known, the shell of which consists mainly of paper or cardboard material, the shell having a thickness of about 0.48 mm and which is disadvantageous in that the layer structure comprises a thick aluminium layer with a layer thickness of about 25 μm.

[0011] US Patent No. 4,642,252 describes a carbonated beverage package having a composite shell, the majority of which is made of paper or cardboard material. The shell thickness of the exemplary embodiments according to Figures 1, 8 and 9 is about 900 μm, i.e. 0.9 mm, respectively. A disadvantage of US Patent No. 4,642,252 is that the innermost layer, i.e. the barrier layer, is spirally wound, which results in a long folded seam length.

[0012] In US Patent No. 4,766,019, a can for carbonated drinks is proposed having a shell made of multiple plastic layers. The shell thickness (or layer thickness) is 22 mils, or about 0.56 mm, in one exemplary embodiment. US Patent No. 4,766,019 explains that the shell thickness should be less than 30 mils (0.762 mm) so that the plastic shell can be closed with a conventional aluminum lid. A drawback is that the entire shell is made of plastic, which is considered to be less sustainable. The innermost barrier layer of US Patent No. 4,766,019 is extruded on a mandrel.

[0013] US Patent No. 4,181,239(A) also shows a can with a plastic shell, which is disadvantageous in that the entire can shell is made up of a plastic layer, and US Patent No. 4,181,239(A) states that the shell thickness should be 85-770 μm, preferably 100-400 μm.

[0014] As is evident from the prior art, it has been recognized that the can shell must not exceed a certain thickness so that it can be closed with a standard aluminum lid of a conventional aluminum can. Secondly, it appears to be recognized that at least some of the wrapped individual layer can shells should not show large deviations in their layer thickness around the circumference. To achieve this, the innermost layer is designed as a thin plastic film or as a laminate of various plastic films and possibly aluminum foils, as available from US Pat. No. 4,181,239(A), US Pat. No. 4,766,019, US Pat. No. 4,642,252. In US Pat. No. 4,642,252, the spirally folded seam of the plastic film and aluminum foil barrier laminate is laminated with an intermediate layer of paper.

[0015] US Patent Application Publication No. 2020189791(A1) discloses a can for containing a liquid and / or gaseous medium that has an overpressure or that develops overpressure during transportation or storage, the can's cylindrical can sleeve mainly consists of a paper or cardboard material and is closed at the bottom by a bottom element and at the top by a lid, the can is capable of withstanding an internal pressure of at least 5 bar, the innermost layer of the can sleeve consists of a straight-wound barrier layer having a longitudinally extending folded seam with the can itself, the barrier layer being a prefabricated laminate consisting of an inner diffusion-resistant barrier film or an inner diffusion-resistant barrier laminate and an outer layer of kraft paper.

[0016] In the case of composite cans made of paper or cardboard consisting of rolled individual layers, it has proven to be a problem that the hold between the individual layers, i.e. the barrier laminate of plastic film and optional aluminium foil, and the subsequent layer of paper or cardboard material, may be insufficient, especially in the folded seam area, for use as packaging for pressurised media, especially carbonated beverages. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] International Publication No. 9959882 [Patent Document 2] European Patent No. 0101139 [Patent Document 3] German Utility Model No. 202007010192 [Patent Document 4] International Publication No. 2012155890 [Patent Document 5] U.S. Pat. No. 3,687,351 [Patent Document 6] U.S. Pat. No. 4,642,252 [Patent Document 7] U.S. Pat. No. 4,766,019 [Patent Document 8] U.S. Pat. No. 4,181,239 [Patent Document 9] US Patent Publication No. 2020189791 Summary of the Invention [Problem to be solved by the invention]

[0018] The object of the present invention is to further improve marketable can shells made of composite material for pressurized media, in particular for carbonated beverage cans, which shells can reliably withstand the typical or possible internal pressures of such media and consist mainly of paper or cardboard material. [Means for solving the problem]

[0019] To achieve this object, in one embodiment a can is proposed for containing solid, liquid and / or gaseous media that have a positive pressure or that may generate a positive pressure during transport and storage, the can's cylindrical can shell mainly consisting of a paper or cardboard material and consisting of at least two wound layers, closed at the bottom by a base element and at the top by a lid element, the innermost layer of the can shell being made of a straight-wound barrier layer consisting of a longitudinal seam with itself running in the longitudinal direction of the can, this barrier layer being sealed by one of the following options: the longitudinal seam is sealed on the inside by a film layer of the barrier layer, which film layer simply overlaps the barrier layer in the longitudinal seam area, or the longitudinal seam is sealed by a sealing strip running straight along the length of the can, or The longitudinal seam is a folded seam, in which the inner or outer longitudinal edge of the further layer of the can shell in the form of a rolled layer of paper or cardboard material faces a side of the increased thickness caused by the folded seam.

[0020] To achieve this object, in a further embodiment a can is proposed for containing solid, liquid and / or gaseous media that may have overpressure or may develop such pressure during transport and storage, the can's cylindrical can shell being made mainly of paper or cardboard material, the can shell having an inner barrier layer and an outer barrier layer with at least two rolled intermediate layers of paper or cardboard material in between, the bottom being closed by a bottom element and the top being closed by a lid element, the innermost layer of the can shell consisting of a straight-wound barrier layer having a longitudinal seam running in the longitudinal direction of the can, the longitudinal seam forming an increased thickness in the layer structure, and at least one inner or outer longitudinal edge of the intermediate layer facing a side of the increased thickness caused by the longitudinal seam.

[0021] In one embodiment, at least one inner longitudinal edge of the further layer of the can shell faces a side of the increased thickness caused by the longitudinal seam, and an outer longitudinal edge of this layer overlaps the inner longitudinal edge of this layer.

[0022] In one embodiment, the inner longitudinal edges of at least two of the other layers of the can shell each face a side of the increased thickness caused by the longitudinal seam, and the outer longitudinal edges of each layer overlap the inner longitudinal edges of this layer.

[0023] In one embodiment, the barrier layer is a laminate consisting of an inner diffusion-resistant film or inner diffusion-resistant barrier laminate and an outer layer of cardboard or paper or kraft paper, the barrier layer having a first edge area that overlaps with a second edge area of ​​the barrier layer at the longitudinal seam area.

[0024] In one embodiment, the barrier layer consists of an inner diffusion-resistant film or inner diffusion-resistant barrier laminate and an outer layer of cardboard or paper or kraft paper in the first edge area, the inner edge of which is sealed by a sealing strip.

[0025] In one embodiment, the barrier layer in the first edge area or at least the outer area of ​​the first edge area consists only of an inner diffusion prevention film or inner diffusion prevention barrier laminate, and the inner diffusion prevention film or inner diffusion prevention barrier laminate of the first edge area is attached to the inner diffusion prevention film or inner diffusion prevention barrier laminate of the second edge area.

[0026] In one embodiment the barrier layer consists only of a cardboard or paper or kraft paper layer in the second edge area or at least in the outer area of ​​the second edge area.

[0027] In one embodiment, the cardboard or paper or kraft layer of the barrier layer does not overlap itself.

[0028] In one embodiment, the barrier layer cardboard or paper or kraft layer is layered on itself.

[0029] In one embodiment, the longitudinal seam of the barrier layer extending in the longitudinal direction of the can has an increased thickness, and the inner or outer longitudinal edge of the layer of the can shell in the form of a rolled layer of paper or cardboard material following the barrier layer faces a side of the increased thickness.

[0030] In one embodiment, a longitudinal seam of a barrier layer extending in the longitudinal direction of the can has an increased thickness and a subsequent layer of the can shell in the form of a rolled layer of paper or cardboard material is arranged around the barrier layer, so that the increased thickness caused by the longitudinal seam is also present in said subsequent layer and the inner or outer longitudinal edge of the next subsequent layer of the can shell, following the subsequent layer in the form of a rolled layer of paper or cardboard material, faces a side of the increased thickness.

[0031] In one embodiment, both longitudinal edges of one of the two subsequent layers of the can shell face two opposite sides of the increased thickness portion.

[0032] In one embodiment, the outer sides of the two longitudinal edges of at least one of two subsequent layers of the can shell overlap the inner sides of the two longitudinal edges of the same layer.

[0033] In one embodiment, each of two subsequent layers of the can shell overlaps itself and is present in the area where it overlaps itself without a reduction in thickness, with the inner longitudinal edge of each layer facing the side of the increased thickness portion.

[0034] In one embodiment, the barrier layer itself consists of one or more film layers, with no cardboard or paper or kraft paper layers, and the barrier layers simply overlap in the area of ​​the longitudinal seams.

[0035] In one embodiment, the barrier layer is a laminate consisting of an inner diffusion-barrier film or inner diffusion-barrier laminate and an outer layer of cardboard or paper or kraft paper, the two edges of the barrier layer meeting in the area of ​​the longitudinal seam to form a butt joint, and the area of ​​the butt joint is sealed with a sealing strip.

[0036] In one embodiment, the barrier layer is a laminate of an inner diffusion-barrier film or inner diffusion-barrier laminate and an outer layer of cardboard, paper or kraft paper, and at least one film layer of the diffusion-barrier film or barrier laminate is formed in a U-shape around the inner cut edge of the cardboard, paper or kraft paper layer, or a sealing strip is placed in a U-shape around the inner cut edge of the barrier layer.

[0037] In one embodiment the barrier layer is a laminate of an inner diffusion-barrier film or an inner diffusion-barrier laminate and an outer layer of cardboard or paper, in particular kraft paper, with at least one further layer of paper or cardboard material present around the barrier layer, and it is proposed that the cardboard or paper surface of the barrier layer and the further wrapped layer of paper or cardboard material lying on top of each other are directly bonded, in particular glued, to each other.

[0038] When the barrier layer is formed as a laminate of film and cardboard or paper, especially kraft paper, the film is relaxed, especially in the overlap area of ​​the longitudinal seam, as the tensile forces are dissipated by the cardboard or paper, especially kraft paper, and the straight seam favors circumferential tensile forces rather than adding additional forces in the longitudinal direction of the can, as would be the case if the innermost layer or barrier layer were spirally wrapped.

[0039] If the innermost layer consists of a paper material on the outside and the next layer is made of a paper material, these two paper materials can be directly bonded to each other, in particular glued, so that the fibers of one paper layer are directly bonded to the fibers of the other paper layer by the adhesive, with the adhesive penetrating the fibers on both sides of the paper material. The advantage of this is a particularly firm hold, which cannot be achieved in this way if a plastic barrier layer is present between the paper materials.

[0040] The barrier layer preferably has a thickness of 0.060 mm to 0.145 mm. The kraft paper layer of the barrier layer preferably has a thickness of 0.065 mm to 0.090 mm. The kraft paper layer of the barrier layer preferably has a tensile strength MD of at least 4.0 kN / m and a tensile strength CD of at least 2 kN / m. Preferably, the diffusion barrier film or diffusion barrier laminate has a thickness of 0.033 mm to 0.055 mm.

[0041] Preferably, the barrier laminate comprises an aluminium layer and at least two plastic layers, the aluminium layer being between the two plastic layers.

[0042] Preferably, at least two additional layers of cardboard or paper, in particular kraft paper, rolled separately from one another, are placed on top of the barrier layer.

[0043] The can is preferably capable of withstanding an internal pressure of at least 5 bar.

[0044] In a less preferred embodiment, at least two layers of cardboard or paper, especially kraft paper, have at least one edge region that does not overlap with itself or that has a reduced thickness in the overlap region with itself.

[0045] Preferably, the respective layer thickness of at least two of the further layers of cardboard or paper, in particular kraft paper, is in each case selected from the range of 140 μm to 175 μm. The respective tensile strength of the kraft paper of the kraft paper layers is preferably at least 10 kN / m (MD) and at least 5 kN / m (CD).

[0046] Preferably, the further kraft paper layer and / or the further layer of paper or cardboard material are each wound longitudinally, preferably with their joint or overlap areas located in different peripheral regions or the joint edges facing each other of the two layers of cardboard or paper, in particular kraft paper, are preferably offset from each other.

[0047] Preferably, the joint or overlap area of ​​the cardboard or paper layer, especially the kraft paper adjacent the barrier layer, is offset relative to the longitudinal seam of the barrier layer.

[0048] Preferably, the can has an outer sealing layer applied to the outside of the layer of cardboard or paper, in particular kraft paper, which outer sealing layer may be present, for example, as a film, laminate or coated paper. Preferably, the barrier layer, preferably at least two further layers of cardboard or paper, in particular kraft paper, and preferably also the outer sealing layer, are processed in a winding system to continuously form a hollow tube from which the individual hollow cylinders are cut.

[0049] Alternatively, the outermost layer of at least two layers of cardboard or paper, in particular kraft paper, may already be present before rolling as a laminate of a layer of cardboard or paper, in particular kraft paper, and a barrier film, which is located on the outside of the composite can shell after rolling.

[0050] The outer barrier film or outer sealing layer on the outside of the composite can shell may be a semi-permeable film that allows moisture to escape from the can shell but does not allow moisture to enter the can shell from the outside.

[0051] The material of the outer barrier film or outer sealing layer on the outside of the composite can shell may be recyclable or renewable PE, biodegradable PE, EVOH or other known barrier materials.

[0052] In an alternative embodiment, the outer sealing layer is applied only after the individual hollow bodies have been cut. This can be done by fastening a tubular sleeve of an outer moisture-proof material over the individual hollow bodies. A shrink tube, preferably made of shrink film, is placed over the cylindrical hollow bodies and formed on the can shell by heat and the associated reduction in diameter. Preferably, the two cut edges of the hollow bodies are covered with a tubular sleeve, so that moisture cannot penetrate therein. The placement of the sleeve or shrink tube is advantageously carried out before the two end sections of the individual hollow bodies are formed on the outside. The gluing or fitting of the sleeve or shrink tube onto the hollow bodies can be carried out before or during the bending outward of the ends of the hollow bodies. However, the placement and inward of the sleeve onto the hollow bodies can also be carried out after the two end sections of the individual hollow bodies are formed on the outside.

[0053] Covering the cut edge of the hollow body with a tubular sleeve comprises rolling the tubular sleeve around the cut edge into the interior of the hollow body. The tubular sleeve preferably projects at both ends into the interior of the hollow body by at least 3 mm, in particular by at least 4 mm. Advantageously, the tubular sleeve can be welded to the barrier layer or barrier laminate in the area where they overlap inside the hollow body.

[0054] The tubular sleeve comprises or consists of a plastic film, which is preferably made of a polyolefin.

[0055] The tubular sleeve may be a shrink sleeve or an expansion sleeve.

[0056] The paper layer of the hollow body located under the tubular sleeve is preferably printed. The printing can be applied before this paper layer is wound or on the tubular body after it has been wound, either already on the endless tube on the mandrel of the winder or after the endless tube has been cut onto the individual hollow bodies. However, the printing can also be arranged on the inside and / or outside of the tubular sleeve.

[0057] The tubular sleeve is preferably attached to the almost or completely dry hollow bodies at the end of the transport path of the individual hollow bodies cut from the endless tube. The hollow bodies are preferably moved continuously along the transport path. Drying devices can be arranged along the transport path or the transport path can pass through at least one drying device. Less preferably, the hollow bodies can be temporarily stored, for example in a drying device, until they are sufficiently dry.

[0058] The tubular sleeve is then placed longitudinally over the hollow body or bodies, or the hollow body or bodies are pressed longitudinally into the tubular sleeve. The tubular sleeve projects beyond each can shell at both ends, where it is folded inward and glued or preferably welded to the barrier layer (inner liner) of the can shell. The tubular sleeve can be supplied individually or as a continuous tube, which is cut at the next location for each can shell after the can shell or shells have been inserted.

[0059] After the individual hollow bodies have been cut, the outer sealing layer can be applied by coating or wrapping with a film, in which case the two cut edges of the hollow bodies are preferably also covered by the coating or film.

[0060] Applying the outer sealing layer after cutting the individual hollow bodies is particularly useful if the layer structure above the two cut edges of the hollow bodies does not dry sufficiently due to the materials used, in particular the glue adhesive and its application amount, if the outer side of the layer structure has already been sealed with a winding system.

[0061] As an alternative to a film-like outer barrier layer, the outermost of at least two layers of cardboard or paper, in particular kraft paper, can already be coated on one side with a barrier material, e.g. paint, on the rear outer side before being wound up.

[0062] Less preferably, after manufacture, the exterior of the hollow tube or cut-off hollow cylinder can be coated with a barrier material, such as paint.

[0063] For example, a water-based polymer coating or a UV paint can be used as the paint.

[0064] Preferably, the cut edges of the individual hollow cylinders, where the paper material of the cardboard or paper, in particular kraft paper, layer is exposed, are sealed, for example by applying a tape or film or coating with a barrier material, such as paint, waterproof glue or liquid plastic. Particularly preferably, the cut edges are sealed by impregnation, i.e. by applying a liquid which penetrates or is more or less absorbed into the fiber matrix of the cardboard or paper, in particular kraft paper, layer at the cut edge, so that a liquid-resistant edge area is formed in the cardboard or paper, in particular kraft paper. Such impregnation can also be used when the outermost layer of the can has one (in the case of overlapping) or two (in the case of butt joint seams) exposed longitudinal absorbent edges.

[0065] For the impregnation, it is preferred to use the polymer mixture as an aqueous solution or emulsion.

[0066] Preferably, the cut edges of the individual hollow cylinders are bent outwards to facilitate positioning of the base element and the lid or to improve retention of the base element and the lid.

[0067] In one embodiment, a liquid or gas condensed or plasma coating is applied to the barrier layer, which in one embodiment is applied after rolling to the inside of the formed hollow body.

[0068] Coatings with silicon oxide (SiOx) are particularly preferred. Coatings, particularly SiOx coatings, are particularly useful in embodiments in which the barrier layer does not form a folded seam with itself, i.e., has a simple overlap or butt seam with itself, for example.

[0069] Instead of or in addition to silicon oxide (SiOx), the barrier layer may also comprise another oxide layer, in particular another semi-metal oxide layer or a metal oxide layer.

[0070] In a preferred embodiment, a coating is provided which consists of or comprises nanocellulose, in particular microfibrillated cellulose (MFC). The cardboard or paper material, in particular the kraft paper material, of the barrier layer preferably comprises nanocellulose, in particular microfibrillated cellulose (MFC). Nanocellulose, in particular microfibrillated cellulose (MFC), can be used in the present invention as a film, in a plastic film or in a paper material (and thus in other layers of the cardboard or paper, in particular the kraft paper material) to increase the barrier properties and / or strength.

[0071] According to the invention, it is preferably realized that the can shell does not exceed the required maximum layer thickness and that in the region of the longitudinal seam the barrier layer still has tolerable deviations in shell thickness, so that the can shell can be closed with a standard aluminium can lid and it is also possible to fill and close the can by standard aluminium can filling.

[0072] Usefully, for the production of hollow cylinders, where the individual layers of the can shell according to the invention are fed around a mandrel and preferably glued over the entire surface, known winding mandrel systems can be used with a round winding mandrel, so that standard plants operating continuously for the production of can shells according to the invention can be used with little adaptation effort. The round structure of the can according to the invention is required so that it can be closed with a standard can lid, and the cylindrical body is more resistant to pressure than other shapes, for example the approximately rectangular bodies with rounded corners that are quite common for general packaging purposes.

[0073] Advantageously, the construction of the composite can shell according to the invention allows the production of pressure resistant containers in plants previously used for packaging of conventional consumer goods. Surprisingly, it has been shown that by using a barrier layer consisting of cardboard or paper, in particular kraft paper, and a barrier film or barrier laminate in the preferred thickness range of the present invention, stretching of the barrier film or barrier laminate on the mandrel is prevented and straight winding proves to be much stronger than spiral winding, so that the operating speed of known plants can be advantageously increased.

[0074] Instead of winding at least two further layers of cardboard or paper, in particular kraft paper, in the longitudinal direction of the mandrel in the same way as the barrier layer, the at least two further kraft paper layers can also be wound obliquely around the straight-wound barrier layer, in which case the displacement and edge areas of the kraft paper can be chamfered or graded. The oblique winding of the at least two further kraft paper layers can be performed in the same direction for each layer or in opposite directions to each other. However, this variant with obliquely wound further kraft paper layers has the disadvantage that the joint or overlap areas of the kraft paper layers cross the longitudinal seams of the barrier layer, with the result that weak spots can occur at these locations. In the case of counter-winding, the joint or overlap areas of the at least two kraft paper layers also cross, which can also result in weak spots there.

[0075] Therefore, preferably, at least two further layers of cardboard or paper, in particular kraft paper, are also rolled straight.

[0076] A less preferred or potentially less useful modification resulting from the present invention could be found in using a paper or kraft paper web laminated with plastic (particularly PE) on one or both sides instead of a layer of cardboard or paper, in particular kraft paper, and making the connection between the layers by welding the adjacent plastic layers of the two layers. Thus, at least one layer has an outer PE film and at least one further layer has an inner PE film, which are welded together, in particular by ultrasonic welding, in particular when the layers are applied on the mandrel of the winder. Of course, all layers could also be fixed by plastic-plastic (PE-PE) welding. To arrive at this alternative embodiment, in at least one or all parts of the present specification where a glue adhesive for joining two surfaces is mentioned, it is theoretically possible to replace the glue adhesive by a plastic film, and therefore the surfaces to be glued are welded together instead. PE-PE welding is common in the manufacture of beverage cartons, which have the disadvantage that they are not suitable for carbonated drinks and for media with or generating strong positive pressure. The layer structure of a beverage carton (barrier layer (PE or PE-Alu-PE)-paper-plastic layer (PE)) can theoretically be used as the innermost layer of a can with a longitudinal seam (simple overlap with the usual inner strip of the beverage carton or a folded seam) in order to roll on top of it at least one additional layer with an inner plastic layer (PE) and an outer cardboard or paper layer, the outermost layer of the layer structure having an outer barrier layer, for example made of PE. However, unlike a normal beverage carton, the layer structure is cylindrical and is closed with suitable closure elements (can base and can lid) rather than welding the layer structure to itself at the ends.

[0077] The present invention will be described with reference to the drawings. [Brief description of the drawings]

[0078] [Figure 1] 1 shows an exploded view of a fluid container according to the present invention in the form of a beverage can according to a first embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view of the two-layer beverage can of FIG. 1, shown greatly enlarged. [Diagram 3] FIG. 2 is a schematic cross-sectional view of a beverage can according to a second and third layer embodiment, the layers being shown greatly enlarged. [Figure 4] FIG. 1 shows a schematic cross-sectional view of a beverage can having a first layer including a barrier layer on the inside, two edge regions of which are brought outwardly over the wound layer and then welded together with the barrier layer, after which a glue adhesive is applied onto the wound layer and glued. [Diagram 5] 1 shows a schematic diagram of a manufacturing process for a cylindrical can shell. [Figure 6] 1 shows a schematic of bending of a can shell edge; [Figure 7] 1 shows a schematic diagram of the arrangement of plugging elements. [Figure 8] 13 shows another variation of the preformed profile of the radial cross section with a silicon-based sealing ring. [Figure 9] FIG. 2 is an elevational view of a longitudinal section of a finished can with beaded gas-tight edges on the bottom and lid. [Figure 10] 1 shows diagrammatically a first section of a plant according to the invention for filling cardboard or paper composite can shells and / or aluminium can shells. [Figure 11] 2 shows diagrammatically a second section of a plant according to the invention for filling cardboard or paper composite can shells and / or aluminium can shells. [Figure 12] 3 shows diagrammatically a third section of a plant according to the invention for filling cardboard or paper composite can shells and / or aluminium can shells. [Figure 13] 1 shows a longitudinal section of a first embodiment of a cylindrical can shell according to the invention; [Figure 14] 2 shows a detail of a longitudinal section of the layer structure of the first embodiment; [Figure 15] FIG. 2 is a layer structure of the first embodiment, showing a detail of a cross section through a longitudinal seam of the barrier layer. [Figure 16]2 shows a longitudinal section of a second embodiment of a cylindrical can shell according to the invention. [Figure 17] 4 shows a detail of a longitudinal section of the layer structure of the second embodiment. [Figure 18] 4 shows the layer structure of the second embodiment, detailing a cross section through a longitudinal seam of the barrier layer. [Figure 19] 3 shows a longitudinal section of a third embodiment of a cylindrical can shell according to the invention. [Figure 20] 1 shows a detail of a longitudinal section of the layer structure of the third embodiment. [Figure 21] 11 shows the layer structure of the third embodiment, detailing a cross section through a longitudinal seam of the barrier layer. [Figure 22] 4 shows a longitudinal section of a fourth embodiment of a cylindrical can shell according to the invention. [Diagram 23] 10 shows a detail of a longitudinal section of the layer structure of the fourth embodiment. [Figure 24] 11 shows the layer structure of the fourth embodiment, detailing a cross section through a longitudinal seam of the barrier layer. [Diagram 25] 1 shows a longitudinal section of a fifth embodiment of a cylindrical can shell according to the invention. [Figure 26] 13 shows a detail of a longitudinal section of the layer structure of the fifth embodiment. [Figure 27] FIG. 11 is a layer structure of a fifth embodiment, showing a detail of a cross section through a longitudinal seam of the barrier layer. [Figure 28] 1 shows a longitudinal section of a sixth embodiment of a cylindrical can shell according to the invention. [Figure 29] 13 shows a longitudinal section of a seventh embodiment of a cylindrical can shell according to the invention. [Diagram 30] 13 shows a detail of a longitudinal section of a layer structure of the seventh embodiment. [Diagram 31] FIG. 13 is a layer structure of the seventh embodiment, showing a detail of a cross section through a longitudinal seam of the barrier layer. [Diagram 32] FIG. 2 shows the layer structure of a cylindrical can shell according to the invention, detail of a cross section through a longitudinal seam of the barrier layer with a sealing strip at the outer seam. [Diagram 33] Schematically illustrates possible overlap areas of layers. [Diagram 34] 1 shows a longitudinal cross section of one embodiment of an additional layer structure of a cylindrical can shell adjacent to a barrier layer. [Diagram 35] 13 shows a longitudinal section of a further embodiment of an additional layer structure of a cylindrical can shell adjacent to a barrier layer. [Diagram 36] 1 shows a first embodiment having an edge of a barrier layer forming a butt joint and a further layer positioned thereon. [Figure 37] 13 shows a second embodiment having an edge of a barrier layer forming a butt joint and a further layer positioned thereon. [Figure 38] 13 shows a third embodiment having an edge of a barrier layer forming a butt joint and a further layer positioned thereon. [Figure 39] 13 shows a fourth embodiment having an edge of a barrier layer forming a butt joint and a further layer positioned thereon. [Diagram 40] 13 shows a fifth embodiment having an edge of a barrier layer forming a butt joint and a further layer positioned thereon. [Diagram 41] 13 shows a sixth embodiment having an edge of a barrier layer forming a butt joint and a further layer positioned thereon. [Diagram 42] 13 shows a seventh embodiment having an edge of a barrier layer forming a butt joint and a further layer positioned thereon. [Diagram 43] 1 shows a first embodiment including an increased thickness portion in a first intermediate layer. [Diagram 44] 13 illustrates a second embodiment including an increased thickness portion in the second intermediate layer. [Diagram 45] 1 shows a first embodiment having a self-overlapping intermediate layer. [Figure 46] 1 shows a second embodiment having a self-overlapping intermediate layer. [Figure 47] 13 shows a third embodiment having a self-overlapping intermediate layer. [Figure 48] 13 shows an embodiment having a U-shaped seal in the barrier layer. [Figure 49] 13 shows an embodiment having a U-shaped seal in the barrier layer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0079] Before describing the individual figures, the fluid container according to the invention can be described in general terms, in particular as a beverage can, designed as a pressurized container, and for this purpose as a hollow cylindrical can body, which is composed of an interior for receiving the beverage, a bottom member and a lid member, the bottom member closing a first longitudinal end of the hollow cylindrical can body formed, and the lid member closing a second longitudinal end of the hollow cylindrical can body. The can body consists of at least one rolled inner material layer and one rolled outer material layer, i.e. at least two wraps or layers of cardboard composite material or kraft paper, the layers extending exactly 360° or, in another embodiment, slightly longer than the entire wrap. A combination of layers exactly one wrap length and layers a little longer is possible. The layers are preferably rolled at right angles to the axis of the can body to be produced, so that the required overlap and seam length are minimized and therefore maximum compressive strength is obtained. However, a longer seam is required in a spiral winding, where the longitudinal edges of the winding bands are joined together to form a tight overlap and seam. Such a winding, also called spiral winding, is found so far in cylindrical table bombs, stacked potato chip containers or containers for any kind of other suitable goods. The rolled inner material layer of the pressure-resistant can, preferably also heat-resistant can according to the invention, has an axially extending inner seam and is formed by a cardboard composite layer or a kraft paper layer, which cardboard composite layer or kraft paper layer is coated, preferably only on one side, on the side facing the interior of the can, with a gas-tight and aroma-tight barrier composite, and the rolled outer material layer has an outer seam, preferably formed by a kraft paper layer, and the seam formed by the overlap is preferably offset with respect to the seam of the inner material layer with respect to the circumference of the can. If a third layer of cardboard composite is present, its overlap or seam is preferably again offset with respect to the circumference of the can with respect to the seam of the central layer.

[0080] According to this fluid container, a beverage container or a cylindrical beverage can is provided in a structurally simple manner and at a cost, which is characterized by a simple structure and the use of recyclable materials. Such a beverage can can surprisingly be designed and manufactured to be sufficiently pressure-resistant, in particular by consisting of several layers and wraps, so that it can be used for carbonated as well as non-carbonated beverages and can withstand pressures of up to 11 bar, even though it is mainly made of bare cardboard composite material. With the exception of a minimal inner coating or barrier layer, the shell mainly consists of cardboard material or kraft paper. This beverage can is also food-safe. The can body according to the invention consists of cardboard or even paper, i.e. kraft paper, and is no longer made of aluminum. By sealing the inner material layers with the help of a barrier composite, a barrier is obtained that completely blocks steam, aromas, fats and oxygen. This barrier composite is applied, for example, by a hot casting method with an extruder. The materials used in the barrier composite are a polyolefin layer and at least one layer of a binder. If necessary, an additional layer of aluminum can be used, in which case the total surface weight of this innermost layer is approximately 60 g / m 2 ~130g / m 2 In a further alternative, the barrier composite may further comprise a layer of ethylene-vinyl alcohol copolymer, whereby the total surface weight is 50 g / m 2 ~100g / m 2 can be achieved.

[0081] The kraft paper layer of the outer material layer is preferably coated on one side facing the inside of the can with a polyolefin layer, the basis weight of which is at least 10 g / m 2 , up to 50 g / m 2 It is made of polyethylene PE or polyethylene terephthalate PET. The ideal basis weight is 20 g / m 2 It has been found that the advantageous barrier effect of polyethylene terephthalate (PET) can be used in this case, thus making an important contribution to environmental protection and waste reduction.

[0082] Recognizing that beverage cans can function as packaging and therefore the desire to label the contents on the outside, the kraft paper layer of the outer material layer is formed to be printable or paintable and waterproof on one side of the outside opposite the interior of the can, thus providing an outer surface on which advertising messages can be printed or painted. The rolled inner material layer and the rolled outer material layer are preferably glued together over their entire surfaces, which allows the seam to remain offset relative to the circumference of the can, enhancing compressive strength.

[0083] To increase the stability of the fluid container or beverage can in an environmentally friendly way, a triple wrap is advantageously produced by applying at least one rolled intermediate layer between a rolled inner material layer and a rolled outer material layer, the intermediate layer also being formed by a kraft paper layer, the inner material layer, the at least one intermediate material layer and the outer material layer being glued over the entire surface onto the opposing kraft paper layer. The at least one rolled intermediate material layer has a middle seam, which is preferably offset with respect to the inner seam and the outer seam with respect to the circumference of the roll. A staggered arrangement of the inner seam, the middle seam and the outer seam is particularly advantageous in terms of air tightness and pressure resistance when filling with carbonated beverages.

[0084] Particularly advantageous is a barrier composite of the innermost polyolefin layer and at least one adhesion promoter layer. In order to increase the mechanical stability of the inner material layer, particularly when achieving high compressive strengths, pressures of 11 bar and above, the barrier composite further comprises a layer of aluminum and a thickness of at least 60 g / m 2 , up to 130g / m 2 However, the material selection adds only a small amount to the weight of the fluid enclosure, while the inner material layer can be toughened with the appropriate material selection.

[0085] Alternatively, to increase the mechanical stability of the barrier composite, an additional layer of ethylene-vinyl alcohol copolymer may be used instead of the aluminium monolayer, in which case the total basis weight is at least 50 g / m 2 , up to 100g / m 2 Ethylene-vinyl alcohol copolymers also have the necessary properties to form a barrier. In yet another embodiment with enhanced mechanical stability, the total basis weight is furthermore at least 50 g / m 2 , up to 100 g / m 2 A layer of polyvinyl alcohol can be used as a barrier composite, where the polyvinyl alcohol has high tensile strength and flexibility.

[0086] At least 60g / m2 to reduce the total weight of the fluid container 2 , up to 180 g / m 2 A kraft paper layer having a basis weight of 1000 g is suitable. The base and / or lid elements can be manufactured for good pressure resistance of the metal can, preferably, as is conventional, from aluminium.

[0087] In the following the individual figures are described and explained in more detail. In figure 1 a fluid container according to the invention in the form of a beverage can 1 is shown in a schematic single-part view. The beverage can 1 comprises a tubular section, i.e. a hollow cylindrical can body 2, a can interior 3 serving to receive the beverage, a base element 4 and a lid element 5. The base element 4 serves to close a first longitudinal end 6 of the can body 2, and the lid element 5 is provided to close a second longitudinal end 7 of the can body 2. The base element 4 and the lid element 5 are preferably made of metal, preferably aluminium. The beverage can 1 may have a diameter of 35 mm to 600 mm and a height of 100 mm to 250 mm, preferably a diameter of 45 mm to 70 mm and a height of from 100 mm.

[0088] 2 shows in principle a first variant with a two-layer can body in cross section, the layers being shown considerably enlarged. A first kraft paper layer 18 with an in-line polyolefin layer as a barrier composite is wound around the inner layer 11 around a central cylindrical steel mandrel and the edge in the direction of winding is glued or welded together with a first seam 15. A second kraft paper layer 18 is then wound onto the first layer 11 as the outer material layer 12 and the edge in the direction of winding is welded or glued together with a seam 16 opposite the seam 15 of the can body 2 to produce the can body 2 with a hollow can interior 3.

[0089] In figure 3 a second embodiment of a beverage container 1 is shown in a cross section through the can body 2, so that it can be seen that with respect to the first embodiment of figure 2, in that in this second embodiment the structure of the can body 2 has three material layers 11, 14, 12, instead of only two layers. The following description applies to both embodiments and the differences between the two embodiments are highlighted.

[0090] In both embodiments shown in Figures 2 and 3, the can body 2 consists of a rolled inner material layer 11 and a rolled outer material layer 12. In the second embodiment according to Figure 3, there is a further material layer, namely a rolled intermediate material layer 14, which is arranged between the inner material layer 11 and the outer material layer 12. It is also possible to arrange more than one intermediate material layer 14 between the inner material layer 11 and the outer material layer 12, but it is shown that three intermediate material layers 14 represent a kind of maximum value, and that it is not necessary to further increase the number of intermediate layers in order to increase the stability.

[0091] The inner material layer 11, the outer material layer 12 and, in the second embodiment, the intermediate material layer 14 are unwound from a material web roll. Their edge regions are then ground, preferably by machine, to form either an incline or a step so that the later overlapping edge regions are not thicker than the thickness of the cardboard composite layer itself. The material web is then wound around a mandrel 23 transversely to its direction of travel and perpendicular to the can body 2, producing the can body 2 and the later closed can 1. The overlapping edge regions of the individual material layers are then form-fittedly connected to one another by glue bonding. As a result, the wound inner material layer 11 has an inner seam 15 and the outer material layer 12 has an outer seam 16. Thus, in the second embodiment, the intermediate material layer 14 has an intermediate seam 17.

[0092] For the function and aesthetics of fluid containers, in particular also beverage cans, it is advantageous if the individual seams 15, 16 and optionally 17 are not arranged at the same circumferential position, as shown in Fig. 3, but rather the inner seam 15 in the first embodiment of Fig. 2, the outer seam 16 and the intermediate seam 17 in the second embodiment of Fig. 3 are additionally arranged at different circumferential positions after the material layers 11, 12 and optionally 14 are glued together. It is of no importance whether the inner seam 15 is arranged offset by 180° with respect to the outer seam 16, as shown in Fig. 2, or whether the seams 15, 16 and 17 are arranged offset by about 15° with respect to each other, as shown in Fig. 3. It is useful that the seams 15, 16 and optionally 17 are arranged offset relative to each other and are not arranged at the same circumferential position of the can body 2.

[0093] As substrate, the inner material layer 11 and the outer material layer 12 are each formed by a kraft paper layer 18, and, if present, the intermediate material layer 14 is also formed by a kraft paper layer 18. In this case, each kraft paper layer 18 preferably has a thickness of at least 40 g / m 2 , up to 180 g / m 2 and has a basis weight of at least 80 g / m 2 , up to 120 g / m 2As an alternative substrate, sack paper with high tensile strength is also being considered.

[0094] According to Figures 2 and 3, in both embodiments, the kraft paper layer 18 of the outer material layer 12 is coated on one of its outer sides facing away from the can interior 3 with a polyolefin layer 19 as a barrier composite. This two-layer structure of the outer material layer 12 is shown diagrammatically with dashed lines, and the representations in Figures 2 and 3 do not reflect the actual layer thickness. The polyolefin layer 19 preferably has a thickness of at least 10 g / m 2 , up to 40 g / m 2 and has a basis weight of 20 g / m 2 A basis weight of about 100 g is preferred. Furthermore, the polyolefin layer 19 may or may not be semi-permeable. As an alternative to the polyolefin layer 19 (not shown), the kraft paper layer 18 of the outer material layer 12 may be printed or painted on one of the exterior sides facing away from the can interior 3.

[0095] 2 and 3, in both embodiments the inner material layer 11 is one-sidedly coated, on the side facing the can interior 3, with a gas- and aroma-tight barrier composite 20. Again, the two-layer structure is shown diagrammatically by dashed lines in the respective figures. The barrier composite 20 itself may be multi-layered.

[0096] As regards the inner material layer 11, one of the sides facing the can interior 3 can be coated with a gas-tight and aroma-tight layer. Again, the two-layer structure is shown diagrammatically in the respective figures with dashed lines. Preferably, this layer is sprayed, printed or applied by a coating, such as a plasma coating. Particularly preferably, this layer comprises an inorganic barrier material. Particularly preferably, this layer comprises a non-metallic inorganic barrier material.

[0097] Particularly preferably, this layer comprises silicon oxide (SiOx) as barrier material. Preferably, this layer is applied directly to the paper material of the inner material layer 11. The paper material of the inner material layer 11 can be provided with a thin plastic layer, preferably in the form of a primer, before the application of the SiOx coating. Alternatively, the inner material layer 11 can already be present as a laminate of a cardboard, paper, in particular a kraft paper layer and a barrier film, on or in which an additional SiOx layer is present. This layer can already be present on the inner material layer before rolling or can be applied before rolling. This layer can be applied after the inner material layer 11 has been rolled, in particular after the entire hollow body has been rolled. Plasma coating is particularly suitable for applying a barrier layer made of SiOx.

[0098] This layer preferably contains nanocellulose, in particular microfibrillated cellulose (MFC).

[0099] The inner material layer 11 preferably contains nanocellulose, in particular microfibrillated cellulose (MFC).

[0100] The plastic barrier layer or barrier composite may include at least one layer of a polyolefin layer and an adhesive. In addition, the barrier composite 20 may then have a layer of aluminum, ethylene-vinyl alcohol copolymer, or polyvinyl alcohol. In the case of an additional layer of aluminum, the barrier composite 20 preferably has a thickness of at least 60 g / m 2 , up to 130g / m 2 , preferably 110 g / m 2 With an additional layer of ethylene-vinyl alcohol copolymer or polyvinyl alcohol instead of aluminum, the barrier composite 20 preferably has a total basis weight of at least 50 g / m 2 , up to 100g / m 2 , preferably 70 g / m 2 The total basis weight is

[0101] Considering the above layer structure, it can be seen that in the first embodiment according to Figure 2, the rolled inner material layer 11 and the rolled outer material layer 12 are preferably glued over the entire surface of the opposite sides of the respective kraft paper layers 18. In the second embodiment according to Figure 3, the inner material layer 11, the intermediate material layer 14 and the outer material layer 12 on the opposing kraft paper layers 18 are preferably glued over their entire surfaces.

[0102] In summary, this exemplary fluid container described as a beverage can is made mainly of cardboard material and is suitable for both non-carbonated and carbonated beverages. It is preferably a three-piece linearly manufactured mainly cylindrical fluid container - for uniform pressure absorption - although other shapes are theoretically possible, such as the shape of a 5 liter beer keg. The fluid container consists of a can body 2, made of a composite of multi-layered cardboard and barrier cardboard, a base element 4, preferably made of metal, preferably aluminium, and a lid element 5, preferably made of metal, preferably also aluminium. The lid element 5 is further provided with a known device for opening, preferably a pull ring, and may optionally be provided with a means allowing re-corking.

[0103] For production, as shown in Figures 4 and 5, the innermost turn, i.e. the innermost layer 11 acting as a barrier web, is formed around a mandrel 23. In this case, the edge area of ​​the layer protruding beyond the outer circumference of the turn is preferably arranged further outwards than the other edge areas. The two overlapped edge areas are preferably connected to each other, for example welded by induction welding or ultrasonic welding if a plastic layer rests on a plastic layer in the overlapping area, or glued if at least one of the adjacent layers in the overlapping area is made of paper. As shown, an adhesive or filler material, in particular a glue adhesive 22, can be applied to the overlapping area 52, so that the two edge areas of the wound layers, which are located one on top of the other, are glued to each other.

[0104] As shown in FIG. 5, the next layer 14 of cardboard composite material is wound simultaneously and slightly offset in space around the mandrel 23 and the existing layer 11, here connected according to the version of FIG. 4, and the next layer 14 is connected to it by gluing. The edge areas of the second layer 14 are preferably ground in a stepped manner so that they can be reliably connected to one another by overlapping, which overlap is glued to form a central seam 17. In FIG. 5 it is also shown that the third layer 12 of cardboard composite material, the outer layer, is wound temporally and locally with a very slight offset around the central layer 14, the positive overlap is also glued to form an outer seam 16. The outermost layer may be coated with an outer material, for example with a very finely pored layer, so that water vapor can escape from the can body and conversely does not penetrate into the can body. This coating is preferably polyethylene PE, polypropylene PP or polyethylene terephthalate PET. The outermost seam 16 can be sealed with a sealing strip (shown in dotted lines) of PE, PP, PET with or without binder or adhesive, which is applied with or without heat depending on the configuration. Instead of applying a strip 46 to the resulting continuous tube 27 moving over the mandrel 23, the outermost seam 16 can be sealed with hot liquid PE.

[0105] In the case of the industrial production of cans made of cardboard composite material, this material is supplied in the form of prefabricated sheets of kraft paper with the respective coating wound in rolls, from which the material is unwound and fed to a winding device as shown in FIG. 5. For example, in the example of FIG. 5, there will be three rollers as the web of the three layers 11, 14 and 12 to be wound. After unwinding, the edge areas of the webs 14, 12 are preferably ground by machine to produce an inclined surface 44 or a step 21. Mainly these rollers, together with the glue adhesive and the base and lid elements, can be fed to a can filling machine for the production of fluid containers, but without empty containers and therefore without bulky goods.

[0106] Before being fed to a winding device, the webs 11, 14, 12 are coated on one of their flat sides with an adhesive, preferably a glue adhesive.

[0107] Then, as shown in FIG. 5, the "continuous" web of the individual layers 11, 14, 12, i.e. the web that initially forms the innermost layer 11, is wound around a fixed cylindrical steel mandrel 23 by a machine station feeding and pulling the layers along the steel mandrel 23. The material web runs between the steel mandrel 23 and several successive rollers (not shown), each having a U-shaped cross section. At the innermost layer 11, an overlap of the two edges of the barrier layer occurs, as shown in FIG. 4. The innermost layer 11 wound on a tube then goes over a further part of the steel mandrel 23. A contact roller (not shown) holds the innermost layer 11 fed onto the mandrel 23 and ensures that the innermost layer 11 is transported over the mandrel 23.

[0108] Next, on the same machine, immediately behind the innermost layer 11, a central layer 14 is locally applied to the innermost wrapping or layer 11. An inclined surface 44 is preferably cut into the step 21 or longitudinal edge of this central layer 14, overlapped by winding on the mandrel 23, and bonded by a pre-applied glue adhesive. And finally, the outer layers are simultaneously applied and locally slightly recessed on the previously wound layer 14.

[0109] The pipe 27 made of a cardboard composite material with three layers bonded together is then fed to a cutting device 26, for example a clocked front-back guillotine, as shown in FIG. 5, which cuts the pipe 27 into pipe sections 28 at the desired positions. The cutting can be preferably carried out by a moving guillotine, but also by known multi-rotary blade cutters. In this case, a carriage with several rotary blades moves at production speed with the continuous tube 27, so that several pipe sections 28 can be cut in one operation. After cutting, the pipe sections 28 preferably pass through a heat tunnel, which removes moisture from the glue adhesive. Heat can be generated in various ways. Preference is given to hot air.

[0110] After the pipe section 28 has been cut to the desired length depending on the desired can volume, the cut edge of the open end of the pipe section 28 is machined into a protuberance. For this purpose, a rotating spreading tool is inserted into the open end from both sides. Figure 6 shows this spreading possibility. The can body 2 is inserted into a hollow cylinder 48 with a rounded inner edge 51. This curved inner edge 51 is set back by a steel roller 49 rotating about an axis 50, which moves to define the wall of a cone. The steel roller 49 rolls over the upper edge of the can body 2 in one or more passes over the curved inner edge 51, slightly spreading the layer. The result is a projection as shown in the following figure 7. The cut edges are preferably sealed after this carding or after spreading, for example by painting with a dispersion adhesive, such as liquid polyethylene PE or a dispersion adhesive, or other suitable fast-setting and food-grade adhesive, so that moisture does not penetrate inside the kraft paper layers, since the subsequent filling necessarily takes place in a humid atmosphere. The cut edges are then treated again with heat to minimize the setting time. For this purpose, infrared is preferred at this point. These tube sections 28 are then placed in a line in an upright position in a conveying device and then pass through a carousel 30, as shown in FIG. 10, on which a machine 32 starts, on the open top side of each pipe section 28, a capping element, for example a bottom element 4, separated from a supply magazine 31, and forms a radially tight seal around the edge area of ​​the open pipe section 28 with the outer edge area of ​​the bottom edge facing radially outward of the capping element.

[0111] Fig. 7 shows this step of firmly crimping a closure element in the form of a base element 4 or a lid element 5. The base element and the lid element can be standard bases or lids used to seal conventional aluminium cans and can then be assembled on the same machine. The base element 4 or the lid element 5 is made of aluminium and has a radially protruding edge region 41, i.e. an area protruding beyond the diameter of the can body 2. The base element 4 or the lid element 5 with the edge region 41 is brought into overlap with the edge region 42 of the can body 2 by the machine. The crimping is then carried out by the machine 32, which for this purpose crimps the cantilevered two-layer part 41, 42, i.e. the edge 41 together with the edge 42 of the can body, i.e. rolls it over about 360°, creating a tightly formed seam. As shown in Fig. 7, the cut edge of the can body 2 is a seal 37 made of moisture-proof material. The lid element 5 or the bottom element 4 comprises a composite material 38 , usually an elastic sealant, which is applied in the area of ​​the protruding edge region 41 facing the edge region 42 of the can body 2 .

[0112] Preferably, the composite material 38 extends from the inside of the curl 39 (the outermost downward curvature of the edge) of the lid element 5 or bottom element 4 to a shoulder 40 of the lid element 5 or bottom element 4, the composite material 38 extending at least partially beyond the height of the shoulder 40 and at least partially beyond the inner radius of the curl 39. Preferably, the composite material 38 extends at least half the height of the shoulder 40.

[0113] Figure 8 shows an alternative base or lid 4, here shown in diametral cross section. As can be seen, a silicone based sealing ring 47 is inserted into the downwardly opening groove formed thereby. The lid is attached using the same machinery as for a conventional aluminium can. The silicone seal provides a better fit and the overlapping areas are rolled inwards together.

[0114] Figure 10 shows a rotary transfer machine 32 with a carousel 30, which, as described above, attaches the bottom elements to the can bodies and crimps the edge of the bottom element to the edge of the can body. Then, as shown in Figure 11, the pipe sections 28 open on one side are turned upside down in the conveyor channel so that the open side faces upwards. They then pass through a filling station 33, in particular a carousel filling station, where each pipe section 28 is filled with a defined filling quantity. Finally, as shown in Figure 12, the bottom-capped filling tube sections 28 pass through a carousel 34, on which a machine 35 inserts from a supply magazine 36 a single lid element 5 with a pull ring closure into the open upper side of each filling tube section 28, and then the radially protruding edge of the lid element 5 is crimped sealingly around the edge area of ​​the open tube section 28.

[0115] The filled and sealed container 1 is shown in cross section along its longitudinal axis, as will be shown later in Figure 9. The can body 2 and the top and bottom flanges 43 are visible, which sealingly secure the lid 5 and base 4 together.

[0116] In Fig. 13 a first embodiment of a can shell 101 is shown in a longitudinal section through a cylindrical container. The can shell 101 has, from the inside to the outside, a barrier layer 102, a first intermediate layer 103, preferably at least one second intermediate layer 104, an outer paper or kraft paper layer 105 and an outer barrier layer 106.

[0117] The barrier layer 102 has a circumferential lap seam that runs the length of the can shell 101, where two layers of the barrier layer 102 overlap one above the other.

[0118] The first embodiment shown in Figures 13 to 15 comprises only a barrier film or a barrier laminate 108 of multiple film layers as the barrier layer 102. The barrier layer 102 is moisture resistant and airtight on both sides and at its cut edges. A simple overlap of the barrier layer 102 is sufficient to form a tight longitudinal seam.

[0119] Figures 14 and 15 show the embodiment of figure 13 in detail, where the barrier layer 102 is shown as a barrier laminate 108. When making a longitudinal seam, it is advantageous not to have to glue dissimilar materials together, since bonding dissimilar materials, for example paper material to plastic, generally requires more special adhesives and / or longer time than bonding paper to paper or plastic to plastic, resulting in a weaker connection. In one embodiment, the barrier laminate is welded to itself in the overlap area. In addition to the already mentioned induction welding and ultrasonic welding variants, in all embodiments of the invention, welding can also be performed by applying heat directly to the plastic, for example by hot air.

[0120] The overlap length of the longitudinal seams in the circumferential direction of the can shell 101 is preferably 1 to 6 mm, particularly preferably 2 to 4 mm, in particular 3 mm.

[0121] Deviating from Figures 13 to 15, in the embodiments of Figures 16 to 31 the barrier layer 102 is designed as a composite of a kraft paper layer 107 and a barrier film or as a composite of a kraft paper layer 107 and a barrier laminate 108 of multiple film layers, which makes the barrier layer 102 easier to wrap and more stable.

[0122] Preferably, the overlap length of the longitudinal seams in the circumferential direction of the can shell 101 is between 1 and 6 mm, particularly preferably between 2 and 4 mm, in particular 3 mm.

[0123] As shown in Figures 16 and 31, the innermost layer of the can shell 101 may preferably be formed by a barrier laminate 108 which is laminated onto a kraft paper layer 107. The bonding of the barrier laminate 108 and the kraft paper layer 107 is already performed before winding the cylindrical can shell 101. The material of the barrier layer 102 is preferably produced in the form of a composite of the kraft paper layer 107 and the barrier laminate 108, which is then wound into a roll and then fed as a roll to the winding process of the cylindrical can shell 101.

[0124] 16 to 18 show a second embodiment.

[0125] In the longitudinal seam area, in the embodiment of Figures 16-18, the barrier layer 102 has an overlap with itself and the two layers of the barrier layer 102 overlap each other. To seal the inner cut edges of the barrier layer 102, a sealing strip 110 is attached, which protrudes beyond the cut edges on both sides and is there glued or welded to both inner foil parts of the barrier laminate 108.

[0126] In the area of ​​the longitudinal seam, seen from the inside to the outside, there is first the sealing strip 110, then the barrier laminate 108, followed by the kraft paper layer 107, which are already firmly connected to one another before winding. The kraft paper layer 107 adjoins a further layer of the barrier laminate 108, which are preferably glued to one another during winding. The further layer of the barrier laminate 108 is followed by a further kraft paper layer 107, which are already firmly connected to one another before winding.

[0127] A third embodiment is shown in Figures 19 to 21. In this embodiment, the barrier layer 102 is wrapped without overlapping, so that two edges of the barrier layer extending in the longitudinal direction of the can shell 101 meet and form a butt joint. A sealing strip 110 is applied to seal the longitudinal seam at the abutting edges.

[0128] Less preferably, the abutting edges can be sealed or made liquid-tight by applying a liquid sealant, such as a hot melt.

[0129] A fourth embodiment is shown in Figures 22 to 24. In this embodiment, the barrier laminate 108 or barrier film protrudes beyond the kraft paper layer 107 so that the cut edge of the kraft paper layer 107 is covered or sealed by the barrier laminate 108 or barrier film. In Figure 24, both the kraft paper layer 107 and the barrier laminate 108 in a first edge region overlap the kraft paper layer 107 and the barrier laminate 108 in a second edge region, and the barrier laminate 108 in the first edge region overlaps the second edge region a greater distance than the kraft paper layer 107.

[0130] A fifth embodiment is shown in Figures 25 to 27. In this embodiment, the barrier laminate 108 or barrier film protrudes beyond the kraft paper layer 107 so that the cut edges of the kraft paper layer 107 are covered or sealed by the barrier laminate 108 or barrier film. In the embodiment shown in Figure 27, only the barrier laminate 108 in the first edge region overlaps with the kraft paper layer 107 and the barrier laminate 108 in the second edge region. The kraft paper layer 107 in the first edge region is butt-jointed with the kraft paper layer 107 in the second edge region, which may result in a slight gap between the edges of the kraft paper layers, as shown.

[0131] A sixth embodiment is shown in Fig. 28. In this embodiment, the barrier laminate 108 or barrier film protrudes beyond the kraft paper layer 107 in a first edge region, and the kraft paper layer 107 protrudes beyond the barrier laminate 108 in a second edge region. The barrier laminate 108 in the first region rests inside the exposed kraft paper layer 107 in the second region. As shown, the two edges of the barrier laminate 108 can abut, in which case the sealing strip 110 covers the abutting edges. In another embodiment, the barrier laminate 108 in the first edge region overlaps the barrier laminate 108 in the second edge region, in which case the sealing strip 110 is not necessary.

[0132] A seventh embodiment is shown in figures 29 to 31. In this embodiment, the barrier laminate 108 or barrier film protrudes beyond the kraft paper layer 107 in the first edge region and the kraft paper layer 107 protrudes beyond the barrier laminate 108 in the second edge region. The kraft paper layer 107 in the first edge region rests inside the exposed kraft paper layer 107 in the second edge region. The kraft paper layer 107 in the first edge region can abut the barrier laminate 108 in the second edge region or have a gap between them. The barrier laminate 108 in the first edge region overlaps the barrier laminate 108 in the second edge region and is glued or welded. The two overlapped kraft paper layers 107 in the first and second edge regions can in particular be glued together with a glue adhesive.

[0133] 16 to 31, the outer layer of the barrier layer 102 is thus formed all around by the kraft paper layer 107. The kraft paper layer 107 is preferably untreated on the outside, i.e., not painted or laminated, and therefore the outside is formed of a kraft paper material.

[0134] In the embodiment of figures 16 to 31, the inner intermediate layer 103 is arranged around the outer side of the barrier layer 102 during the winding process, the intermediate layer 103 being untreated, i.e. not coated or laminated on the inside and outside. The inner side of the inner intermediate layer 103 is glued over its entire surface with the outer side of the barrier layer 102, where preferably the kraft paper material is glued directly with the kraft paper material, so that the glue adhesive can penetrate into the fibre matrix of both layers, whereby a particularly high final strength of the adhesive is achieved.

[0135] Although less preferred, other adhesives such as hot melt adhesives or two-part adhesives may be used, but the lower final strength of hot melts and the difficulty of processing two-part adhesives may be cited as major disadvantages compared to glue adhesives or water-based adhesives. Adhesives in this specification are understood to be aqueous solutions of adhesives. In particular, known paper glue adhesives may be used.

[0136] Although less preferred, a combination of two or more different adhesives may be used, either together to bond two layers together or each to bond a different layer together, for example a hot melt and a water-based adhesive may be applied side by side onto the layers to bond two layers together.

[0137] Solvent-based adhesives and glue adhesives in particular can be applied in liquid state or as a foam.

[0138] Foams have the advantage that less liquid volume is required to cover the surface being bonded or glued compared to non-foaming adhesives or glues.

[0139] 13-15, the inner intermediate layer 103 is wrapped around the barrier laminate 108 or barrier film. In one embodiment, the inner intermediate layer 103 has a plastic or laminated film coating on its inside. In this embodiment, the coated or laminated surface of the inner intermediate layer 103 can be glued or welded to the barrier laminate 108 or barrier film.

[0140] As shown in Figures 13 to 33, preferably at least one further intermediate layer 104 is disposed around the outside of the inner intermediate layer 103 during the winding process, and preferably this further intermediate layer 104 is not treated, i.e., not coated or laminated on the inside.

[0141] The use of at least two intermediate layers 103, 104 is more complicated and involves higher material costs than using only a thick layer for the can shell, but has the advantage that two thin layers, especially the kraft paper layer, can be processed faster on the winder and the stability of the can body can surprisingly be increased even more compared to the use of one thick layer.

[0142] Preferably, two intermediate layers 103, 104 and an additional paper or kraft paper layer 105 are used, as shown in Figures 13 to 33, with the inner intermediate layer 103 and each additional intermediate layer 104 preferably being uncoated on both sides and the outer paper or kraft paper layer 105 preferably being untreated or uncoated at least on the inside.

[0143] Particularly preferred can shells are manufactured with heights ranging from 130mm to 150mm, outer diameters ranging from 50mm to 60mm, and inner diameters ranging from 48.6mm to 58.6mm.

[0144] Particularly preferred dimensions of the sealed can are: outer height 134 mm, inner height 133 mm, outer diameter 52.4 mm, inner diameter 51.2 mm, content volume about 270-275 ml, filling capacity 250 ml.

[0145] As explained, the can has as its innermost layer a barrier layer 102, which in the embodiments of Figures 16 to 34 is made of a film material and kraft paper, and in the embodiments of Figures 13 to 15 is made only of a film material. The film material is preferably a composite film comprising an aluminium foil and at least one plastic film, which together form a barrier laminate 108. The barrier laminate 108 preferably comprises an aluminium foil, particularly preferably with a layer thickness of 6 to 9 μm, which is between two plastic layers.

[0146] The barrier laminate 108 preferably has a structure in which, from the inside to the outside, a plastic film, preferably PE, an aluminum foil, preferably an adhesion promoter in the form of Surlyn, a plastic film, preferably PE, are arranged. The individual layer thicknesses of the barrier laminate 108 are particularly preferably 10-25 μm for the plastic film, 2-5 μm for the binder, 6.5-7.5 μm for the aluminum foil, 10-25 μm for the plastic film.

[0147] The barrier laminate 108 preferably has a thickness of 30 μm to 55 μm. The barrier laminate 108 particularly preferably has a thickness of 35 to 50 μm, in particular 40 to 45 μm. The barrier laminate 108 preferably has a thickness of 45 to 75 g / m 2 , especially 50 g / m 2 ~65g / m 2 The sheet has a basis weight of 1.0 g.

[0148] In one embodiment, the barrier layer 108 also comprises at least one layer of a silicon-containing barrier material, in particular SiOx, present on or in the barrier stack or replacing one, several or all of the layers of the barrier stack.

[0149] In one embodiment there is a layer made of SiOx with a layer thickness of at least 50 nm, in particular at least 500 nm.

[0150] The kraft paper layer 107 of the barrier layer 102 preferably has a thickness of 60 μm to 90 μm. The kraft paper layer 107 of the barrier layer 102 particularly preferably has a thickness of 70 to 85 μm. The kraft paper layer 107 of the barrier layer 102 preferably has a thickness of 40 g / m 2 ~80g / m 2 , especially 50-70g / m 2 , especially 60g / m 2 The sheet has a basis weight of 1.0 g.

[0151] The barrier layer 102 has a thickness of preferably 90 μm to 145 μm, and particularly preferably 110 to 135 μm.

[0152] The tensile strength MD of the kraft paper of the kraft paper layer 107 is preferably at least 4 kN / m, in particular at least 5.0 kN / m. The tensile strength CD of the kraft paper of the kraft paper layer 107 is preferably at least 2 kN / m, preferably at least 2.5 kN / m.

[0153] In a second embodiment of the barrier layer 102, it has the structure of a barrier laminate 108 having, from the inside to the outside, a heat seal coating, a plastic layer, preferably in the form of PET, an aluminium layer in the form of aluminium foil, a plastic layer in the form of adhesive, and a kraft paper layer 107 made of kraft paper. 2 The heat-sealing lacquer preferably has a basis weight of 1.6 g / m 2 The aluminum foil has a layer thickness of 7.7 μm and a basis weight of 20.8 g / m 2 , and the adhesive plastic layer has a basis weight of 2 g / m 2 Overall, the barrier layer 102 has a layer thickness of about 60 μm and a weight of about 65 g / m 2 The sheet has a basis weight of 1.0 g.

[0154] The barrier layer 102 is wrapped longitudinally around the mandrel to form a longitudinal seam, forming a tubular body with the inner plastic film of the barrier laminate 108 facing towards the mandrel and the kraft paper layer 107 facing away from the mandrel.

[0155] The next layer, the inner intermediate layer 103, is preferably made of kraft paper, particularly preferably with a basis weight of 125 g / m 2 , tensile strength MD>12 kN / m, thickness 0.160 μm. Both sides of the kraft paper are untreated. Preferably, the inner kraft paper layer 103 has a thickness of 95 g / m 2 ~135g / m 2 and / or a tensile strength of more than 10 kN / m and / or a thickness of 0.140 mm to 0.175 mm.

[0156] The kraft paper layer is wound around the tubular body of the barrier layer 102 and thereby directly and completely bonded, in particular by glue bonding, to the kraft paper layer 107 of the barrier layer 102 .

[0157] For the glue adhesion, a glue adhesive, preferably polyvinyl acetate, is applied to the outside of the barrier layer 102 or the inside of the inner intermediate layer 103 at a rate of 10 to 25 g / m 2, especially 15 to 20 g / m 2 It is preferable to apply the coating in an amount of

[0158] The next layer is the intermediate layer 104, e.g. 2 , tensile strength >12 kN / m, and thickness 0.160 mm. Both sides of the kraft paper are untreated. Preferably, the intermediate layer 104 is 95 g / m 2 ~125g / m 2 and / or a tensile strength MD of more than 10 kN / m and / or a thickness of 0.140 mm to 0.175 mm.

[0159] This additional intermediate layer 104 is directly and entirely bonded to the underlying inner intermediate layer 103 by wrapping, in particular by gluing, around the tubular body of the barrier layer 102 and the inner intermediate layer 103 .

[0160] For the glue adhesion, a glue adhesive, preferably polyvinyl acetate, is used, preferably 10 to 25 g / m 2 , especially 15 to 20 g / m 2 on the outside of the inner intermediate layer 103 or on the inside of the additional intermediate layer 104 in an amount of

[0161] Preferably, the can body has a fourth layer formed from an outer paper or kraft paper layer 105. The outer paper or kraft paper layer 105 preferably has a weight of 80 to 130 g / m 2 , especially 100-120g / m 2 The outer paper or kraft paper layer 105 preferably has a thickness of 70 to 120 μm, in particular 90 to 110 μm.

[0162] The outer paper or kraft paper layer 105 is applied to the middle layer 104 in a winding device, preferably with a glue adhesive, preferably polyvinyl acetate, preferably 10-25 g / m 2 , especially 15 to 20 g / m 2 is adhered to the entire surface.

[0163] The can shell 101 preferably comprises a barrier layer 102, an inner intermediate layer 103, an intermediate layer 104 and an outer paper or kraft paper layer 105. The thickness D of the can shell is about 550 μm. The can shell 101 consisting of the barrier layer 102, the inner intermediate layer 103, the intermediate layer 104 and the outer paper or kraft paper layer 105 preferably has a total thickness of 500 to 650 μm, more preferably 550 to 620 μm. The can shell 101 consisting of the barrier layer 102, the inner intermediate layer 103, the intermediate layer 104 and the outer paper or kraft paper layer 105 preferably has a tensile strength CD of more than 300 N / 15 mm, in particular more than 350 N / 15 mm, i.e. more than 20 kN / m, in particular more than 23 kN / m. Preferably, the can shell 101, consisting of the barrier layer 102, the inner intermediate layer 103, the intermediate layer 104, and the outer paper or kraft paper layer 105, has a strength of at least 400 g / m 2 , in particular at least 450 g / m 2 The sheet has a basis weight of 1.0 g.

[0164] Preferably, this outer kraft paper layer 105 is provided on the side facing the outside of the can with an outer barrier layer 106, e.g. a monolayer barrier film, with or without pinholes, preferably with a basis weight of 15 g / m 2 and / or coated with polyethylene (PE) or varnish to a thickness of 15 microns.

[0165] Alternatively, the outer layer may consist only of an outer barrier layer 106 in the form of a barrier film, with or without pinholes, preferably 25 g / m 2 In this case, the inner intermediate layer 103 and the second intermediate layer 104 can have their material thickness adjusted so that the overall material thickness of the can shell is maintained.

[0166] Depending on the height and diameter of the can, the number of intermediate layers 104 may be greater than 1, for example, for a can having a height of 245 mm and a diameter of 175 mm, it is envisaged that the number of central layers is preferably 2. For example, with a preferred thickness of 0.160 μm per layer 103, 104, 105 and a thickness of 127 μm for the barrier layer 102, the total thickness D is 767 μm.

[0167] Depending on the height and diameter of the can, the inner intermediate layer 103, the intermediate layer 104 and the outer kraft paper layer 105 can have greater strength, for example, for a can with H of 245 mm and D of 175 mm, each has a thickness of 265 μm. For example, the barrier layer 102 has a thickness of 127 μm, resulting in a total thickness D of 922 μm.

[0168] Increasing the number of layers is more advantageous than increasing the layer thickness because thinner layers can achieve faster can processing speeds and greater can body stability for the overall basis weight of the kraft paper used.

[0169] The tensile strength index MD, as the quotient of the tensile strength MD and the basis weight of the kraft paper used in the kraft paper layer 107 and layers 103, 104, 105, is preferably in the range of 70 to 120 Nm / g.

[0170] The tensile strength index CD, as the quotient of the tensile strength CD and the basis weight of the kraft paper used in the kraft paper layer 107 and layers 103, 104, 105, is preferably in the range of 35 to 70 Nm / g.

[0171] The tensile strength index MD of the kraft paper used is preferably greater than 80 Nm / g. The tensile strength index MD is particularly preferably greater than 100 Nm / g.

[0172] The tensile strength index CD of the kraft paper used is particularly preferably greater than 40 Nm / g. The tensile strength index CD is particularly preferably greater than 50 Nm / g.

[0173] In addition to the kraft paper layer 107, the layer structure preferably consists of at least two further kraft paper layers 103, 104 made of kraft paper having specific tensile strength indices MD and CD. At least one of the kraft paper layer 107 or the further layers 103, 104 may be formed of another cardboard material having specific tensile strength indices MD and CD. Kraft paper is distinguished from conventional papers by its high tensile strength indices in MD and especially in CD (cross direction).

[0174] Preferably, the kraft paper of the kraft paper layer 107 and the kraft paper of layers 103, 104 are unbleached. The paper or kraft paper of the outer paper or kraft paper layer 105 may be bleached, which may be useful for printing on its outside. The outer paper or kraft paper layer 105 may already be printed with a product design before being rolled, which printing may be beneficially present between the paper or kraft paper layer 105 and the outer barrier layer 106. The cut at the cutting device 26 is then registered against the printing.

[0175] Fig. 32 shows a cross section of a particularly preferred construction of a can shell 101 according to the invention. In this construction, the inner intermediate layer 103 and the further intermediate layer 104 have side edges formed obliquely so that the two edges of the layers facing the respective web materials overlap each other without increasing or substantially increasing the layer thickness of the layers in the overlapping area. As an alternative to the oblique shape, other shapes of edges are also suitable, such as stepped edges or connecting edges, as shown in Fig. 33. Generally speaking, it is preferred that at least one of the two edges of at least one of the layers 103, 104, 105 is provided with a shape such that the thickness of the overlapping edge is reduced in the area where the two edges overlap. Particularly preferably, the two edges of at least one of the layers 103, 104, 105 are provided with a shape such that the thickness of the overlapped edge is equal to the thickness of the layer itself. Particularly preferably, the innermost intermediate layer 103 is provided with such a construction. Preferably, at least one of the applied intermediate layers 104 is provided with such a structure, and particularly preferably, all of the applied intermediate layers 104 are provided with such a structure.

[0176] As shown in figure 32, the edges of the outer kraft paper layers 105 preferably meet at the joint, where the gap is sealed by applying strips 109 (also called stripes) of PE, PET or PP or by applying a sealant with a spray head after the can body is formed. The abutting edges of the outer kraft paper layers 105 are effective because the resulting gaps are more regular and therefore more visually appealing and there is no reduction in the layer thickness in the edge regions of the outer kraft paper layers 105, but they are less stable against external mechanical influences.

[0177] Although less preferred, the edges of the inner intermediate layer 103 and / or the edges of the additional intermediate layer 104 may come into contact forming butt joints in the respective layers, which may adversely affect the stability of the layer structure.

[0178] To manufacture a can shell 101 according to the invention, the barrier layer 102 is first fed as a web material along the length of a winder mandrel and moved along the length of the mandrel, forming two edges around the periphery of the mandrel that meet on opposite sides of the mandrel, surrounding the mandrel with the web material.

[0179] To create the longitudinal seam, the two edges of the web material of the barrier layer 102 are overlapped over the mandrel. The barrier layer 102 preferably does not have any glue applied to the outside.

[0180] Therefore, particularly preferably, the winding machine according to the present invention is provided as an improvement over the known prior art with an applicator, e.g. an applicator provided with a nozzle, which applies adhesive (e.g. glue or hot melt) in a targeted manner to at least one of the two juxtaposed regions of the barrier layer 102 in the longitudinal seam area.

[0181] This effectively prevents air from being trapped in the overlap area, which may adversely affect the stability of the can shell 101. The internal pressure of the can pressurizes the air trapped within the layer structure, and the pressure of the trapped air can either stress the layer structure from the inside or cause the trapped air to try to escape towards the closed end of the lid, where creep damage can occur.

[0182] In a next step, the inner intermediate layer 103 is preferably fed as a web material in the longitudinal direction of the winding mandrel and is moved further in the longitudinal direction of the mandrel so that the inner intermediate layer 103 is placed around the barrier layer 102. The two edges of the inner intermediate layer 103 are formed around the barrier layer 102 located on the mandrel, and these edges meet on the opposite sides of the mandrel, so that the barrier layer 102 located on the mandrel is surrounded by the web material of the inner intermediate layer 103. As explained, the edges of the inner intermediate layer 103 are preferably overlapped so that they are glued to each other. The inner intermediate layer 103 will be provided with glue adhesive on the inside, for example by applying glue adhesive during the feeding of the web material, and when the inner intermediate layer 103 is fitted or pressed against the kraft paper layer 107 of the barrier layer 102, the glue adhesive will be distributed over the entire area between the layers.

[0183] In the next step, zero to preferably up to three additional intermediate layers 104 are sequentially stacked around the inner intermediate layer 103, which are also preferably fed as a web material in the longitudinal direction of the winding machine mandrel and moved in the longitudinal direction of the mandrel. The two edges of each additional intermediate layer 104 are formed around the inner intermediate layer 103 already located on the mandrel, so that these edges meet on the opposite side of the mandrel and the inner intermediate layer 103 located on the mandrel is surrounded by the web material. As explained, the edges of each intermediate layer 104 are preferably overlapped so that they are glued to each other. Each intermediate layer 104 will be provided with glue adhesive on the inside, for example by applying the glue adhesive during the feeding of the web material, and when the intermediate layer 104 is fitted or pressed to the inner intermediate layer 103 already placed on the mandrel, the glue adhesive will be distributed over the entire area between the layers.

[0184] In the next step, the outer paper or kraft paper layer 105 is formed around the outer layers 103, 104 already wound around the mandrel, preferably fed as a web material in the longitudinal direction of the winding mandrel and moved further in the longitudinal direction of the mandrel. The two edges of the outer kraft paper layer 105 are formed around the outer layers 103, 104 already lying on the mandrel, so that they meet on the opposite sides of the mandrel and the layers 103, 104 already lying on the mandrel are surrounded by the web material. As explained, the edges of the outer kraft paper layer 105 preferably do not overlap each other in order to meet at the joint. The outer kraft paper layer 105 will be glued on the inside, for example by applying a glue adhesive during the feeding of the web material, so that when the outer kraft paper layer 105 is fitted or pressed against the lower wound layers 103, 104, the glue adhesive will be distributed over the entire area between the layers.

[0185] As shown in Figure 32, the outer kraft paper layer 105 may preferably already have an outer barrier layer 106, i.e. may be supplied as a laminate or web material coated on one side so that the outer surface is liquid-resistant or liquid-repellent. For example, the outer kraft paper layer 105 may be provided with a waterproof or moisture-proof print.

[0186] If the outer kraft paper layer 105 does not already have a liquid-resistant or liquid-repellent exterior during feeding, it can be provided in the winder or after the winder. For example, a liquid-resistant or liquid-repellent film or laminate can be applied around the outer kraft paper layer 105 in the winder. For example, after winding, the formed hollow cylinder can be sprayed or printed with a liquid-resistant or liquid-repellent substance, in particular a paint. If a liquid-resistant or liquid-repellent film or laminate is applied around the outer kraft paper layer 105 in the winder, this film or laminate can be welded to the plastic side so as to tightly enclose the outer kraft paper layer 105. In the case of a film, a simple overlap is sufficient. For example, in the case of a laminate made of a film and a thin printing or label paper, a folding seam can be provided on it. The barrier layer 106 may be applied in the form of a printed or label layer which, at least on its outer side, is adhered onto the outer kraft paper layer 105, which is then sealed, for example with a strip 109 with glue adhesive, in the abutment areas of its two edges.

[0187] If the outer kraft paper layer 105 already has a liquid-resistant or liquid-repellent exterior during feeding, in a next step the joining areas of the outer layer are preferably sealed on the winder, for example by applying a liquid-resistant or liquid-repellent material as a liquid or by applying a strip 109, in particular in the form of an adhesive tape.

[0188] The outer seam of the outer paper or kraft paper layer 105 or of the further layers arranged thereon can therefore be designed as a folded seam, a simple overlap or a joint (butt joint seam). The butt joint seam can be sealed by hot melt, stripes, tapes or sealing liquid, which means are preferably applied in the winder after winding of the outermost layer and before cutting the individual hollow cylinders. The stripes or tapes can be self-adhesive or present as plastic strips, in particular PE strips, which are fixed by ultrasonic welding.

[0189] Preferably, the hot melt is applied in a winder with a nozzle on the paper tube that sits on a mandrel and moves past the nozzle. Preferably, the nozzle is oriented perpendicular to the gap in the longitudinal butt joint seam of the outermost layer of the paper tube being applied in the winder. The nozzle may be cylindrical or rectangular in cross section and have a straight or flat opening surface.

[0190] However, it is preferable that the nozzle opening surface is concave to fit the cylindrical shape of the paper tube when viewed in the circumferential direction of the paper tube, and that the nozzle opening surface has a uniform distance from the paper tube.

[0191] The hot melt is preferably applied in the winder directly after winding the outermost layer, which is or already has a dense outer barrier layer 106. The hot melt is applied to seal the water-absorbent cut edges of the outermost layer and / or to seal the exposed underlayer 103 or 104 along the butt joint seam. The outer layer is preferably made of a moisture-absorbent material, in particular paper or kraft paper, and is laminated on its outside with a moisture-resistant material, for example a moisture-resistant film or coated with a moisture-resistant substance. The gap of the butt joint seam is preferably in the range of 0.5 to 4 mm. The hot melt is preferably applied in the form of a strip that protrudes over the gap of the butt joint seam, the width of the hot melt strip being preferably at least 1 mm, in particular at least 2 mm, greater than the width of the gap of the butt joint seam. For example, the width of the gap of the butt joint seam is 3 mm and the width of the hot melt strip is 6 mm. The hot melt is applied heated, for example at 160°C to 190°C, and hardened by cooling until the individual cylinders are cut off from the winder mandrel 23. This is preferably assisted by a cooling device, for example in the form of a blower. By sealing the butt joint seam with adhesive, the outer circumference of the can is very flat or homogenous. The film formed on the outer barrier layer 106 by the adhesive or hot melt is, for example, only 0.05 to 0.1 mm thick. Instead of the outer kraft paper layer 105 including the barrier layer 106, it is also possible to use a different paper or cardboard material, preferably one made from or including recycled paper or fiber material.

[0192] In a further embodiment of the outer layer sealing according to the invention, the outer kraft paper layer 105 is provided with an outer barrier layer 106 in the form of a film, the kraft paper layer 105 and the film being present as a laminate and thus being fed together as a material web to a winding device. The film layer is designed to be longer in the transverse direction of the material web than the kraft paper layer 105, so that the edge of the film layer protruding on one side rests on the edge of the other, non-protruding film layer. In this case, the protruding edge of the film layer may be melted or welded on the film layer that does not overlap the kraft paper, or an adhesive, in particular an activatable, in particular a heat-activatable adhesive, may be applied to the underside of the overlap area to bond the film layer to itself.

[0193] After the layers are wound and joined into a tubular body, the individual hollow cylinders are cut from the mandrel using a known cutting machine, as seen in FIG.

[0194] The individual hollow cylinders are then folded at both ends in the edge region.

[0195] The bending is preferably performed over a length range of 5 mm, with the outer edge being bent outwards by 2.5 mm. From the outer edge, the bent region is preferably joined to the non-bendable shell region along a circular path, preferably with a radius of 3-4 mm, in particular with a radius of 3.3-3.5 mm.

[0196] The cut or already folded edges are preferably coated with a sealing liquid so that their absorption capacity is reduced by moisture, preferably by applying the sealing liquid during the bending process. Alternatively, the cut edges can be sealed by applying tape or shrink tubing.

[0197] The bent and finally sealed hollow cylinder is then transferred to a can capping machine where an initial end, preferably the lower end, of the hollow cylinder is closed with a first capping element, e.g., first the bottom element 4. The bottom element 4 is preferably an aluminum bottom element of a conventional aluminum can, which has at least approximately the same volume or the same diameter as the can of the present invention.

[0198] Thereafter, the medium, in particular a carbonated beverage, is filled into the hollow cylinder, which is capped at the bottom, preferably in an amount of 0.25 liters.

[0199] The filled hollow cylinder is subsequently capped at the top with a second capping element, e.g. a lid element 5. The lid is preferably an aluminium lid for a conventional aluminium can, having at least approximately the same volume or the same diameter as the can of the invention.

[0200] The capping and filling is preferably carried out in a clock plant with a capacity of 80,000 cans / hour.

[0201] Preferably, the winder produces 40,000 cans / hour, which means that the speed of the finished pipe in the direction of the winding mandrel is about 1.5 m / s. The desired throughput of 80,000 cans / h cans can be achieved by mirroring the machines, where the flanged can bodies from both machine units are brought together in front of the can bottom sealer.

[0202] Preferably, the can shells 2 of the present invention, originating from a slower winding system, can be capped in the same faster capping and filling plant together with conventional aluminum can shells, more preferably with the same bottom element and the same lid, without tooling changes or time interruptions, which means that the speed of the winding system is no longer critical to the process and the filling plant can be operated at full capacity independently of this.

[0203] The composite cans according to the invention and conventional aluminium cans can be filled and capped in the same plant in batches or alternately, so that the slow production rate of a single winding plant can be compensated for by the production of conventional aluminium cans, for example 40,000 cans per hour and 40,000 aluminium cans per hour can be produced in a plant, advantageously allowing two production lines, i.e. the continuous production of eco-friendly composite cans and the proven aluminium cans, to be produced simultaneously in the plant.

[0204] The sale of composite cans according to the invention is particularly advantageous for product introductions, since it meets the exact needs of the composite shell cans according to the invention and allows the remaining capacity of standard cans to be used, and therefore does not initially lead to the full utilization of conventional filling plants. The simultaneous or sequential use according to the invention of cans according to the invention and of conventional aluminium can filling plants therefore allows the production of aluminium cans to continue, only to be gradually replaced in increasing proportions by the composite cans, further reducing the further inhibition threshold for product conversion. EXAMPLES

[0205] A preferred layer structure according to one of the figures 16 to 33 produces a beverage can with a height of 134 mm, an outer diameter of 52.4 mm and a carbonated beverage filling capacity of 250 ml. As paper or kraft paper layer 105 a low tear resistant wood-free paper is used, in particular a paper layer 105 of Lumiflex™ 110 gsm Stora Enso AG, and a PE coating is applied to the outside of the back of the can. The top and bottom of the beverage can are sealed with a standard base and lid of an aluminium can using a standard capping device.

[0206] The layers used and the resulting layer structure are specified in the table below. [Table 1]

[0207] The tensile strength MD (machine direction) refers to the tensile strength of the kraft paper in the longitudinal direction of the can shell 101, and the tensile strength CD (cross direction) refers to the tensile strength of the kraft paper in the circumferential direction of the can shell 101. It can be seen that the conventional papers used in the paper layer 105 have significantly lower tensile strengths, especially in the cross direction (CD).

[0208] The basis weight of the entire layer structure of the can shell 101 is 18 g / m per layer. 2 The amount of glue applied is increased compared to the sum of the individual layers. The amount of glue applied is 54 g / m2 in total, as glue is applied to the entire surface of the three layers. 2 It becomes.

[0209] The barrier laminate 108 used is a laminate of the following structure: 25 μm thick PE plastic film, 7 μm thick aluminum foil, 3 μm thick Surlyn adhesive, and 15 μm thick PE plastic film.

[0210] Cans thus prepared are suitable for storing and transporting carbonated beverages.

[0211] A particularly preferred layer structure for the container according to the invention therefore has an inner barrier layer 102 consisting of a barrier laminate 108 with a simple overlap seam running in the longitudinal direction of the can and a kraft paper layer 107, on top of which there are two wound layers 103, 104 each with an overlap seam running in the longitudinal direction of the can, the layers 103, 104 including at least one edge with a reduced thickness in the seam area, on top of which there is a wound layer of paper or cardboard material, which wound layer has on the outside an outer barrier layer 106 and a gap forming a butt joint seam running in the longitudinal direction of the can, which gap is sealed with a hot melt, and the layers 103, 104 are directly bonded, in particular glued, to each other and to the lower and upper layers at the kraft paper surface.

[0212] The advantages of the can according to the invention are its recyclability and its good ecological rating. The can of the material used resembles a cardboard packaging coated with plastic, so that the aluminum part, the paper layer and the plastic film can be separated from one another and separated and sorted for recycling by known melting methods similar to this. In particular, the high proportion of renewable resources, especially in the form of paper, gives it an advantage over aluminum and / or plastic cans. The ecological rating of this can is better than that of conventional aluminum cans.

[0213] FIG. 34 shows a variant of the can shell 101 in a longitudinal section through a longitudinal seam of the barrier layer for use in a can 1 containing a solid, liquid and / or gaseous medium that has a positive pressure or that may generate a positive pressure during transport or storage, the cylindrical can shell 101 of the can being made mainly of paper or cardboard material and made of at least two wound layers, closed at the bottom by a bottom element 4 and at the top by a lid element 5, the can 1 being capable of withstanding an internal pressure of at least 5 bar, the innermost layer of the can shell 101 being the innermost layer of the can 1 along the length of the can 1, the innermost layer being the innermost layer of the can shell 10 ... It consists of a straight-wound barrier layer with a longitudinal seam running in the hand direction, the barrier layer being a laminate of an inner diffusion-barrier film or element 108, a central paper or preferably kraft paper layer 107 and an outer plastic layer 111, around which is present the barrier layer of the can shell 101 at least one further wound layer of paper or cardboard material with the inner plastic layer 111, the adjacent plastic layer 111 and the further wound layer of paper or cardboard material of the barrier layer 102 being directly welded to each other. The longitudinal seam can be made according to one of the embodiments of figures 13 to 31.

[0214] The further wound layer of paper or cardboard material having an inner plastic layer 111 may also have an outer plastic layer 111 .

[0215] Furthermore, there may be one or more preferably up to two further layers of paper or cardboard material, each layer having an inner plastic layer 111 and / or an outer plastic layer 111, with adjacent plastic layers 111 of the layers being welded to each other.

[0216] As shown in figure 35, there can be only one plastic layer 111 between the further layers 103, 104, 105 of paper or cardboard material, for example already present in one of the two adjacent layers before winding. In the variant of figure 35, there is no plastic layer 111 between the kraft paper layer 107 and the adjacent layer 103, resulting in paper material overlaid on top of paper material.

[0217] In one embodiment, the layered structure thus consists of a barrier layer, the paper material of which is adhered, in particular glued, to the paper material of the next layer of paper or cardboard material, between which the paper or cardboard material of the next layer and the paper or cardboard material of the outermost layer of the can shell, there being at least one plastic layer 111 between two of these layers. The at least one plastic layer 111 is usefully used to connect the two layers by heating it. Due to the fact that the at least two layers are connected by heated or melted plastic, the amount of liquid introduced into the layered structure by the adhesive or glue adhesive is reduced.

[0218] The stability of the can is improved by directly bonding or gluing two of at least two consecutive layers of paper or cardboard material, the barrier layer being preferably one of these layers, so that the barrier layer and the subsequent layer are particularly firmly connected.

[0219] At least one plastic layer 111, which is disposed between two layers of paper or cardboard material, is preferably provided with perforations or openings, so that moisture can be distributed through the plastic layer 111 between the layers of paper or cardboard material. As a result, moisture brought about by the adhesive or glue adhesive can be effectively distributed between the layers of paper or cardboard material, thereby reducing the overall moisture content of the individual layers.

[0220] The material of the plastic layer is preferably a polyolefin, in particular PE.

[0221] The embodiments of Figures 34 and 35 are useful regardless of how the barrier layer 102 and the outer barrier layer of the can may be implemented. For example, the barrier material 108 of the barrier layer may be in the form of a film, a laminate, a composite film, or a coating, or a combination thereof.

[0222] The further wound layer, made of paper or cardboard material with the plastic layer 111, may in turn preferably have a longitudinal seam of reduced thickness in the overlap area with itself. The outermost layer may again be provided with a butt seam, with any gaps appropriately sealed.

[0223] The paper or cardboard material of one or more layers or all layers of a can according to the invention or according to the can embodiment may preferably be a kraft paper or paper or cardboard material having comparable tensile strength indices MD (Machine Direction) and CD (Cross Direction).

[0224] 36-41 show a further embodiment in which the inner edge of the inner intermediate layer 103 following the barrier layer abuts the edge of the barrier layer 102 and the outer edge of the inner intermediate layer 103 overlaps the inner edge of the inner intermediate layer 103. Depending on how accurately the edge of the inner intermediate layer 103 can be positioned when wrapped around the barrier layer 102 located on the mandrel of the winder, a gap may also be created between the inner edge of the inner intermediate layer 103 and the edge of the barrier layer 102 due to manufacturing. The barrier layer 102 and the inner intermediate layer 103 each have a portion that overlaps with itself, whereby they are wound in a straight line and thus include straight edges extending in the longitudinal direction of the endless tube formed on the mandrel.

[0225] As shown in Figure 36, the inner edge of the second intermediate layer 104 preferably abuts the outer edge of the first intermediate layer 103 and the outer edge of the second intermediate layer 104 overlaps the inner edge of the second intermediate layer 104. If there are further intermediate layers made of paper or cardboard material, in particular kraft paper, they are preferably embodied in the same way.

[0226] As shown in Figure 36, the inner edge of the outer paper or kraft paper layer 105 preferably abuts the outer edge of the underlying layer 104 and the outer edge of the outer paper or kraft paper layer 105 overlaps the inner edge of the outer paper or kraft paper layer 105. As previously described for the other embodiments, the outer paper or kraft paper layer 105 may have or be provided with an outer barrier layer 106.

[0227] Intermediate layers 103 and 104 are preferably present in the same material thickness.

[0228] The further layers 103 and 104 may reduce the material thickness in the area where they overlap themselves in one or both of the two overlapping edge areas.

[0229] The edge of the barrier layer 102 may be formed by simply overlapping with itself, as shown in Figure 37. As shown, the intermediate layer 103 may be of the same thickness as the barrier layer 102. The intermediate layer 103 and the barrier layer 102 may also be present in different material thicknesses.

[0230] The edge of the barrier layer 102 may be formed by having a folded seam with itself as shown in Figure 38. As shown, the middle layer 103 may be of the same strength as the double barrier layer 102. However, the middle layer 103 may also be of a different material thickness.

[0231] As shown in Figures 39 and 40, the first edge of the second intermediate layer 104 may abut the outer edge of the first intermediate layer 103, and the second edge of the second intermediate layer 104 does not extend to the first edge of the second intermediate layer 104. The second edge of the second intermediate layer 104 preferably extends to the beginning of the area of ​​the inner intermediate layer 103 where there is an increased thickness of the layer structure resulting from the overlap of the barrier layer 102 with itself. As can be seen in Figures 39 and 40, the increased thickness in the overlap area of ​​the barrier layer 102 and the overlying layer 103 is hidden by the second additional layer 104.

[0232] As shown in Figures 41 and 42, the outer edge of the inner intermediate layer 103 can be designed to have a reduced thickness, in particular to have a beveled surface. Furthermore, the edge of the additional outer intermediate layer 104 can be designed to have a reduced thickness, in particular to have a beveled surface. As a result, the edges, in particular the beveled surfaces, of the two layers 103, 104 located above and below can be present to overlap. As shown in Figures 41 and 42, the second edge of the second intermediate layer 104 can also or alternatively be designed to have a reduced thickness, in particular to have a beveled surface. As shown in Figure 41, the additional intermediate layer 104 can overlap itself, whereby the beveled surface of the outer edge can be used to attach the outer adjacent layer, which also has a beveled surface. As shown in Figure 42, the additional layer 104 can serve to hide the increased thickness due to the presence of a beveled surface in the area where the thickness change of the composite of the barrier layer 102 and the inner intermediate layer 103 occurs.

[0233] In the embodiments of Figures 37, 39 and 41, the longitudinal seams may be sealed as shown by sealing strips 110. However, instead of as shown, the longitudinal seams may also be sealed simply by a film layer of the barrier layer 102 overlapping the barrier layer 102 in the area of ​​the longitudinal seams, as shown in Figures 15, 24, 27 and 31.

[0234] In the embodiments of Figures 36, 38, 40 and 42, the cut edges of the paper or kraft paper layer 107 of the barrier layer 102 are not exposed to the inside, so the seal is provided by the folded seam itself. The folded seam is identified by the fact that the two edge regions of the barrier layer 102, together with the diffusion barrier laminate 108 or diffusion barrier film or coating, face each other and the two edge regions are folded back onto the barrier layer 102 itself.

[0235] Figures 43 and 44 show diagrammatically an embodiment in which the increased thickness of the seam of the barrier layer 102 is at least largely hidden by a further layer structure. In Figures 43 and 44 the seam is designed as a self-sealing fold seam, but it can also be designed according to one of the embodiments of the seam of the barrier layer 102 described in the other figures.

[0236] In FIG. 43, the seam of the barrier layer 102 is accommodated in a gap of the paper, cardboard or in particular kraft paper material of the intermediate layer 103 adjacent to the barrier layer 102. The two longitudinal edges of the layer 103 are therefore located at a distance from each other on either side of the increased thickness of the barrier layer 102 in the seam area. In this embodiment, the subsequent further paper or cardboard, in particular kraft paper layer 104, preferably runs around the entire circumference of the can shell. The two longitudinal edges of the layer 104 may adjoin or overlap each other and may be reduced in thickness in the overlapping edge region of the layer 104, as shown in FIG. 43. Contrary to what is shown, the butt joint or overlap area of ​​the layer 104 is preferably arranged offset from the seam of the barrier layer 102 and therefore offset from the gap of the layer 103.

[0237] In the embodiment of FIG. 44, the seam of the barrier layer 102 and the layer 103 adjacent to it is accommodated in a gap of a further layer 104 of subsequent paper or cardboard, in particular kraft paper. The two longitudinal edges of the layer 104 are spaced apart from each other and are located on either side of the increased thickness of the barrier layer 102 and the layer 103 in the seam area. In this embodiment, the layer 103 runs around the entire circumference of the can shell. The two longitudinal edges of the layer 103 can abut or overlap each other in the overlapping edge region of the layer 103, as shown in FIG. 44, and thus can be reduced in thickness. As shown, the butt joint or overlap area of ​​the layer 103 is preferably offset from the seam of the barrier layer 102 and thus from the gap of the layer 104.

[0238] The embodiment of Figure 44 has proven to be more effective than that of Figure 43 since in this embodiment, layer 103 directly adjacent to barrier layer 102 is self-contained, resulting in greater stability of the can body, especially in the seam area of ​​barrier layer 102.

[0239] Fig. 45 shows an embodiment in which at least one of the further layers 103, 104 overlaps itself, with no reduction in thickness in the overlapping edge area of ​​the respective layer 103, 104. Both layers 103, 104 are preferably designed in this way. Thus, layer 103 and / or layer 104 have a thickness increase in the form of a simple overlap. The barrier layer 102 can be embodied according to one of the embodiments described herein, in particular with a simple overlap in the seam area or a seam folded over itself. The respective overlaps of layers 102, 103 and 104 are preferably arranged offset from one another so that no total thickness difference occurs. The extent of the overlap of layers 103 and / or 104 can be small, for example in the range of 1 to 10 mm, in particular 1 to 5 mm.

[0240] Preferably, the inner or outer edge of at least one of the respective layers 103, 104 faces the layer structure area where the change in thickness of the layer structure occurs. As shown in layer 103, at least one of the layers 103, 104 may be with its inner longitudinal edge in front of and positioned above the increased thickness portion of the underlying layer, with the outer longitudinal edge of the layer in front of the edge where the increased thickness portion rises.

[0241] As shown in layer 104, at least one of layers 103, 104 can be positioned with its inner longitudinal edge behind the descending edge of the thickened portion of the underlying layer, and the other end can be directed above the thickened portion such that the outer longitudinal edge of the layer overlaps with the inner longitudinal edge of the layer.

[0242] Fig. 46 shows an embodiment in which both further layers 103, 104 overlap with themselves. In the overlapping edge regions of the respective layers 103, 104 there is no reduction in thickness. Thus, layers 103 and 104 have a thickness increase in the form of a simple overlap. The barrier layer 102 can be designed according to one of the embodiments described herein, in particular with a simple overlap with itself or a folded seam in the seam area. The respective overlaps of layers 102, 103 and 104 are arranged offset with respect to each other, so that no total thickness difference occurs.

[0243] Both layers 103, 104 are positioned with their inner longitudinal edges toward the descending side of the thickened portion of the lower layer and are led with their other ends above the thickened portion, with the outer longitudinal edges of each layer 103, 104 overlapping the inner longitudinal edges of each layer 103, 104.

[0244] As shown in Figure 46, the inner longitudinal edges of the layers 103, 104 can face the sides of the increased thickness portion that are not formed by the longitudinal edges of the underlying layers. Alternatively, the inner longitudinal edges of the layers 103, 104 can face the sides of the increased thickness portion that are formed by the longitudinal edges of the underlying layers.

[0245] Preferably, there is a slight gap between the inner edge of each layer 103, 104 and the side of the thickened portion so that the inner edge does not protrude all the way to the side, i.e. does not rest on or above the side.

[0246] Fig. 47 shows a particularly preferred embodiment in which the two further layers 103, 104 overlap themselves. In the overlapping edge regions of the respective layers 103, 104 there is no reduction in thickness. Layers 103 and 104 therefore have an increased thickness in the form of a simple overlap. The barrier layer 102 can be designed according to one of the embodiments described herein, in particular with a simple overlap with itself or a folded seam in the seam area. The respective overlaps of layers 102, 103 and 104 are arranged offset with respect to each other, so that no total thickness difference occurs.

[0247] Both layers 103, 104 are positioned with their inner longitudinal edges facing the downward side of the thickened portion of the lower layer and their other ends directed above the thickened portion so that the outer longitudinal edges of each layer 103, 104 overlap the inner longitudinal edges of each layer 103, 104.

[0248] As shown in Fig. 47, the inner longitudinal edges of the layers 103, 104 can face the same side of the thickening portion. As shown in the example, the inner longitudinal edges of the layers 103 and 104 can each be on the left side of the thickening portion. As illustrated, the outer longitudinal edges of the layers 103 and 104 are in each case on the same side as the thickening portion, i.e. on the side on which the inner longitudinal edges of the layers 103, 104 are also present.

[0249] Preferably, there is a slight gap between the inner edge of each layer 103, 104 and the side of the thickened portion so that the inner edge does not protrude all the way to the side, i.e. does not rest on or above the side.

[0250] The additional layers are preferably arranged in the same manner as shown in Figure 47 for the outer paper or kraft paper layer 105. Layer 105 has its inner longitudinal edge facing the outer longitudinal edge of layer 104, which forms the raised edge of the thickening portion.

[0251] It should be noted that basically, both in the variant of Fig. 47 and in the other variants, the number of layers 103, 104 located between the barrier layer 102 and the outer paper or kraft paper layer 105 can be greater than two. It is preferred that between the barrier layer 102 and the outer paper or kraft paper layer 105 there are 1 to 5 intermediate layers 103, 104 made of paper or kraft paper, in particular 2 to 3 intermediate layers 103, 104.

[0252] Between the barrier layer 102 and the outer barrier layer 106 there are preferably 2 to 6 intermediate layers 103, 104, in particular 3 to 4 intermediate layers 103, 104 made of paper or kraft paper.

[0253] For each of the intermediate layers 103, 104, the inner or outer longitudinal edge of this layer of the can shell, in the form of a wound layer of paper or cardboard material, preferably faces a side of the increased thickness resulting from the longitudinal seam of the barrier layer.

[0254] For at least one, preferably two, three or four of the intermediate layers 103, 104 and optionally layers 105, in an embodiment, the inner longitudinal edge of at least one of the further layers 103, 104 and optionally layers 105 of the can shell 101 faces the side of the increased thickness caused by the longitudinal seam, and the outer longitudinal edge of each layer 103, 104, 105 overlaps the inner longitudinal edge of the same layer 103, 104, 105. For all layers designed in this way, the overlap area of ​​the two longitudinal areas of each layer is preferably twice the material thickness of the layer, and the overlap areas are preferably arranged offset from each other in the circumferential direction. As shown in Figure 47, the overlap areas are preferably arranged adjacent to each other, with a first overlap area of ​​the innermost of these layers adjacent to the side of the increased thickness of the barrier layer 102 and the further overlap areas of the other layers adjacent to the outer longitudinal edge of the respective lower layer.

[0255] In the overlap areas, each intermediate layer 103, 104 and optionally layer 105 is preferably adhered, in particular glued, to itself.

[0256] Figures 48 and 49 show an embodiment in which the sealant is present on both sides of the inner edge region of the inner paper, particularly kraft paper layer 107, as the sealant surrounds the inner longitudinal edge of the entire barrier layer 102 or the inner longitudinal edge of the paper, particularly kraft paper layer 107. The web material of the barrier layer 102 is preferably already present in this way before winding or when it is fed to the winding device. Alternatively, it is also possible to wrap the sealant around the edge of the web material during feeding onto the mandrel of the winding device.

[0257] 48 shows that the barrier laminate 108 or barrier film of the barrier layer 102 can be designed to surround the inner longitudinal edge of the paper, in particular kraft paper, layer 107. During winding, the outer edge region of the barrier layer 102 comes to lie above the folded edge region of the barrier laminate 108 or barrier film that protrudes beyond the longitudinal edge of the paper, in particular kraft paper, layer 107.

[0258] FIG. 49 shows that there may be a sealing strip 110 surrounding the inner longitudinal edge of the barrier layer 102 and thus the inner longitudinal edge of the layer 107 of paper, in particular kraft paper, in a U-shape. During winding, the outer edge area of ​​the barrier layer 102 comes to be located above the folded edge area of ​​the sealing strip 110, which projects beyond the longitudinal edge of the layer 107 of paper, in particular kraft paper. Instead of the sealing strip 110, a coating with a sealing material can also be applied in a U-shape around the inner longitudinal edge of the barrier layer 102. The coating can be applied in liquid or gas form or as a plasma before or during feeding of the material web of the barrier layer 102 to the mandrel of the winder. Inside the can shell, the sealing strip 110 or coating covers the edge area of ​​the barrier laminate 108 or barrier film.

[0259] In a further embodiment, a modification of the embodiment of Figures 41, 39, 37, 34, 28, 21, 18, instead of or in addition to the sealing strip 110, there is a coating applied to the already wound endless tube or, preferably, to the individual can shells already cut from the endless tube, the coating being made of a sealant forming the seam of the barrier layer. As with the sealing strip 110, the coating can be applied as a band application only around the inner longitudinal edge area of ​​the barrier laminate 108. Optionally, the coating can also be applied as a band application on the cut edges of the can shells and / or on the seam of the outermost layer of the can shells.

[0260] In another embodiment, the coating is applied to the entire inside of the can shell. Additionally, the coating can be applied to the cut edges and / or the entire exterior of the can shell. Additional coating of the can shells cut from the endless tube of the winder can be performed in all of the embodiments described herein.

Claims

1. A can (1) containing a solid, liquid and / or gaseous medium that may have excess pressure or that may generate excess pressure during transportation or storage, the can's cylindrical can shell (101) consisting mainly of a paper or cardboard material, comprising at least two wound layers, closed at the bottom by a base element (4) and at the top by a lid element (5), the innermost layer of the can shell (101) consists of a straight-wound barrier layer (102) itself having a longitudinal seam extending in the longitudinal direction of the can (1); a) said longitudinal seam is sealed on the inside by a film layer of said barrier layer (102), said film layer overlapping said barrier layer (102) in the area of ​​said longitudinal seam; b) the longitudinal seam is sealed by a sealing strip (110) extending straight along the length of the can; c) the longitudinal seam is designed as a folded seam, and the inner or outer longitudinal edge of the further layer (103, 104) of the can shell (101) in the form of a wound layer made of paper or cardboard material faces the side of the increased thickness resulting from the folded seam. A can (1).

2. 2. The can according to claim 1, characterized in that the barrier layer (102) is a laminate made of an internal diffusion-preventing film or laminate (108) and an outer cardboard or paper or kraft paper layer (107), the barrier layer (102) having a first edge region overlapping a second edge region of the barrier layer (102) in the area of ​​the longitudinal seam.

3. 3. The can according to claim 2, characterized in that in the first edge region, the barrier layer (102) comprises the inward diffusion-preventing film or inward diffusion-preventing barrier laminate (108) and the outer cardboard or paper or kraft paper layer (107), the inner edge of the first edge region being sealed by a sealing strip (110).

4. 3. The can according to claim 2, characterized in that in the first edge area or at least in the outer area of ​​the first edge area, the barrier layer (102) comprises only the inner diffusion prevention film or the inner diffusion prevention barrier laminate (108), and the inner diffusion prevention film or the inner diffusion prevention barrier laminate (108) of the first edge area is on the inner diffusion prevention film or the inner diffusion prevention barrier laminate (108) of the second edge area.

5. 2. Can according to claim 1, characterized in that the longitudinal seam of the barrier layer (102) extending in the longitudinal direction of the can (1) has an increased thickness and the inner or outer longitudinal edge of the layer (103) in the form of a rolled layer of paper or cardboard material following the barrier layer (102) of the can shell faces a side of the increased thickness.

6. 2. Can according to claim 1, characterized in that the longitudinal seam of the barrier layer (102) extending in the longitudinal direction of the can (1) has an increased thickness and a subsequent layer (103) of the can shell, which is a wound layer made of paper or cardboard material, is located around the entire barrier layer (102), whereby the increased thickness caused by the longitudinal seam is present on said layer (103) and the inner or outer longitudinal edge of a layer (104) of the can shell, which is a wound layer of paper or cardboard material subsequent to the layer (103), faces a side of the increased thickness.

7. 6. Can according to claim 5, characterized in that both longitudinal edges of one of the two subsequent layers (103, 104) of the can shell face two opposite side surfaces of the increased thickness portion.

8. 6. Can according to claim 5, characterized in that the outer sides of the two longitudinal edges of at least one of the two additional layers (103, 104) of the can shell overlap the inner sides of the two longitudinal edges of the same layer.

9. 9. Can according to claim 8, characterized in that both subsequent layers (103, 104) of the can shell overlap each other and are present in the overlapping area with them without a reduction in thickness, and the inner longitudinal edges of the respective layers (103, 104) face the sides of the increased thickness.

10. 2. Can according to claim 1, characterized in that the barrier layer (102) is a laminate made of an inner diffusion-preventing film or inner diffusion-preventing barrier laminate (108) and an outer cardboard or paper or kraft paper layer (107), whereby the barrier layer (102) of the can shell (101) comprises at least one further winding layer (103) made of paper or cardboard material, and the adjacent cardboard or paper surfaces of the barrier layer (102) and the winding layer (103) made of paper or cardboard material are directly bonded, in particular glue-bonded, to one another.

11. 2. Can according to claim 1, characterized in that the barrier layer (102) is a prefabricated laminate made of an internal diffusion barrier laminate (108) and an external kraft paper layer (107), the barrier layer (102) having a layer thickness of 0.098 mm to 0.145 mm, the kraft paper layer (107) of the barrier layer (102) having a layer thickness of 0.065 mm to 0.090 mm, and the diffusion barrier film or the diffusion barrier laminate (108) having a layer thickness of 0.033 mm to 0.055 mm.

12. 2. Can according to claim 1, characterized in that at least one winding layer (103) made of kraft paper is attached on the outside above the barrier layer (102), its inner kraft paper surface being glued, in particular glued, to the kraft paper surface of the barrier layer (102) and its outer kraft paper surface being glued, in particular glued, to the cardboard, paper or kraft paper surface of a further winding layer (104) made of paper or cardboard material.

13. 2. Can according to claim 1, characterized in that the barrier layer (102) itself consists of one or more foil layers and does not have a cardboard or paper or kraft paper layer (107), the barrier layer (102) simply overlapping itself in the area of ​​the longitudinal seam.

14. 2. Can according to claim 1, characterized in that the barrier layer (102) is a laminate made of an internal diffusion-preventing film or internal diffusion-preventing barrier laminate (108) and an outer cardboard or paper or kraft paper layer (107), the two edges of the barrier layer (102) being in contact and forming a butt joint in the area of ​​the longitudinal seam, the abutment area being sealed by a sealing strip (110).

15. 2. Can according to claim 1, characterized in that the barrier layer (102) is a laminate made of an internal diffusion-preventing film or barrier laminate (108) and an outer cardboard or paper or kraft paper layer (107), and at the inner cut edge of the barrier layer (102), at least one film layer of the diffusion-preventing film or barrier laminate (108) is arranged in a U-shape around the kraft paper layer (107) or a sealing strip (110) is arranged in a U-shape around the inner cut edge of the barrier layer (102).

16. 2. The can of claim 1, wherein the medium is a carbonated beverage.

17. containing a solid, liquid and / or gaseous medium that may have excess pressure or that may generate excess pressure during transportation or storage, said cylindrical can shell (101) of said can consisting mainly of a paper or cardboard material; The can shell (101) has an inner barrier layer (102) and an outer barrier layer (106), at least two rolled intermediate layers (103, 104) made of paper or cardboard material, A can (1) closed at the bottom by a base element (4) and at the top by a lid element (5), the innermost layer of the can shell (101) consists of a straight-wound barrier layer (102) itself having a longitudinal seam extending in the longitudinal direction of the can (1); the longitudinal seam forms an increased thickness in the layer structure; At least one of the inner or outer longitudinal edges of the intermediate layer (103, 104) faces a side of the increased thickness resulting from the longitudinal seam. A can (1).

18. 18. Can according to claim 17, characterized in that the inner longitudinal edge of at least one of the further layers (103, 104) of the can shell (101) faces a side of the increased thickness resulting from the longitudinal seam and the outer longitudinal edge of this layer (103, 104) overlaps the inner longitudinal edge of this layer (103, 104).

19. 18. Can according to claim 17, characterized in that the inner longitudinal edges of at least two of the further layers (103, 104) of the can shell (101) each face a side of the increased thickness resulting from the longitudinal seam, and the outer longitudinal edge of each layer (103, 104) overlaps the inner longitudinal edge of the same layer (103, 104).

20. Can according to any one of the preceding claims, characterized in that the outer sealing layer of the can shell (101) is in the form of a tubular sleeve made of a moisture-proof material, said tubular sleeve also covering the two cut edges of the can shell (101).

21. 21. Can according to claim 20, characterized in that the tubular sleeve overlaps the longitudinally wrapped barrier layer (102) of the can shell (101).

22. A method for producing a can according to any one of claims 1 to 19, comprising the steps of: In a first step, the can shell is produced in a continuously operating winding machine, in which the individual layers are applied and successively connected to one another on a winding mandrel, during which the barrier layer (102) is provided with a longitudinal seam extending in the longitudinal direction, after which the resulting tube (27) is cut into individual cylindrical hollow bodies open on both sides, In a second step, the two open ends of the hollow cylindrical body are bent outwardly so that the ends have a circular cross section with a larger diameter than the remaining hollow cylindrical body; In a third step, the lower end of the cylindrical hollow body is closed with a base element (4) using a flange attachment device; In a fourth step, the hollow body closed at the bottom is filled with a medium using a filling system (33), In a fifth step, the top of the filled hollow body, the bottom of which is closed, is closed with a lid element (5) using a crimping device, The fourth and fifth steps, and preferably also the third step, are carried out in a filling system suitable for filling and capping known aluminum cans. A method for manufacturing a can.

23. 23. The method according to claim 22, characterized in that before or after the second step, a tubular sleeve is placed on the outside of the cylindrical hollow body, the tubular sleeve protruding beyond the cylindrical hollow body on both sides and folded inside the cylindrical hollow body.

24. 24. The method of claim 23, characterized in that the tubular sleeve is glued or welded to the barrier layer (102).

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