Closure element and can with closure element

Abstract

The invention relates to a closure element (1) and to a can having a can shell (9), the can shell (9) being able to be closed at both ends by a respective closure element (1). A visco-elastic material (8) is arranged in such a way that, when the can shell (9) is flanged to the closure element (1), said material comes to rest either exclusively in the annular region which, as seen in the longitudinal direction of the can, is present between the outer end of the can shell (9) and the outer end of the closure element (1), or exclusively in an annular region between the can shell (9) and a shoulder (3) of the closure element (1), or is present exclusively in these two regions.

Description

[0001] Closure element and can with closure element

[0002] The invention relates to a closure element of a can. The can can have a can shell made of composite material, which comprises an inner moisture-resistant barrier layer and at least one further layer made of paper or cardboard material.

[0003] WO2022219176A1 relates to a can with a composite can body comprising an inner moisture-resistant barrier layer and at least one further layer of paper or cardboard. WO2022219176A1 discloses a closure element for such a can body, comprising a compound material in the area of ​​an annular horizontal rim, which also extends partially over the shoulder of the closure element, adjoining the rim in the direction of the disc-shaped base element of the closure element. Standard closure elements from aluminum cans are used.Due to the greater thickness of a composite can shell with at least one paper layer compared to an aluminum can, when crimping the closure element around the can shell, the compound material may end up in a place where it is not needed or may even have a negative effect.

[0004] The object underlying the invention is to provide an improved locking element.

[0005] To solve the problem, a closure element according to claim 1 is proposed. Alternatively, a can with a closure element according to claim 6 is proposed to solve the problem. A method according to claim 10 is proposed for manufacturing the can.

[0006] The advantage of this solution is that a tough-elastic material is present in the finished can in the vertical extension of the can shell between the can shell and the closure element and / or between the can shell and the shoulder of the attached closure element.

[0007] The type, quantity, and / or application method result in a comparatively thick layer of the tough-elastic material at this point, compared to the prior art. The tough-elastic material itself is preferably harder or tougher than conventional compound materials used in the can industry.

[0008] The locking element is preferably made of metal, in particular aluminum.

[0009] The can casing can be made of tinplate, aluminum, plastic or composite material.

[0010] In particular, when the sealing elements are attached to a can with a can shell made of composite material, comprising at least one layer of paper or cardboard, an improved sealing effect is achieved.

[0011] One embodiment relates to a closure element of a can, which, in its unattached state, comprises a base element, a shoulder, an annular rim area, and a curl, wherein the shoulder includes a rounded section with which the shoulder transitions into the rim area, the shoulder connecting the rim area and the base element, and the curl adjoining the rim area on the outside, wherein the closure element has an annular application of a tough-elastic material in a partial area of ​​the shoulder, which partial area is designed according to one of the following variants:

[0012] In one variant, it is proposed that the shoulder area is limited exclusively to the curve.

[0013] In one variant, it is provided that the shoulder section includes a section of a truncated cone-shaped wall of the shoulder.

[0014] In one variant, it is planned that the sub-area of

[0015] The shoulder is limited exclusively to the curve and an adjoining part of the truncated cone-shaped wall.

[0016] In one variant, the sub-area is designed to consist of three areas of approximately equal width, with one area being the curve and the other two areas adjoining the curve on both sides.

[0017] In one embodiment, the tough-elastic material is provided for to comprise ethylene vinyl acetate.

[0018] The tough-elastic material, in particular the ethylene vinyl acetate, may contain additives. The tough-elastic material, in particular the ethylene vinyl acetate, may contain a thickening agent.

[0019] In one version, the amount of tough-elastic material applied per closure element is between 15 mg and 70 mg.

[0020] In one embodiment, it is provided that this is attached to a can with a can shell made of composite material, which can shell comprises an inner moisture-resistant barrier layer and at least one further layer of paper or cardboard material.

[0021] One embodiment relates to a can with a can body which is closed at both ends by a closure element, wherein the respective end of the can body is crimped with the closure element, wherein a tough-elastic material is present between the can body and the closure element, either exclusively in the annular area which, viewed longitudinally along the can, lies between the outer end of the can body and the outer end of the closure element, or exclusively in an annular area between the can body and a shoulder of the closure element, or exclusively in both of these areas. In one embodiment, the thickness of the tough-elastic material between the can body and the closure element is provided to be at least 0.03 mm, preferably at least 0.08 mm.

[0022] In one variant, the can casing is provided for to consist of composite material, comprising an inner moisture-resistant barrier layer and at least one further layer of paper or cardboard material.

[0023] One embodiment relates to a method for closing a can with a closure element, the can having a can shell, wherein in a first step a tough-elastic material is applied to a limited annular area of ​​the closure element, or of a blank of the closure element with subsequent forming, or of the can shell, in a second step an end of the can shell is crimped with the closure element, wherein after crimping the tough-elastic material is present in an annular area between the can shell and the shoulder of the closure element and / or in that annular area which, viewed in the longitudinal direction of the can, is located between the outer end of the can shell and the outer end of the closure element.

[0024] It is preferred that the crimping of the can shell with the closure element is carried out without heating the closure element, i.e., without thermal softening of the tough-elastic material. It is preferred that, in the first step, the tough-elastic material is applied to the limited annular area by a single pass over the annular area with an application device, in particular a nozzle or needle, whereby the beginning and end of the application coincide exactly. In other words, the tough-elastic material is preferably applied as an annular bead. This differs from the usual application of compound material, which is carried out in at least two overlapping layers.

[0025] To ensure the seamless application of the tough-elastic material, the application device is preferably supplemented by an additional control system compared to known application devices, whereby the application quantity and / or the time of the start and end of the application is controlled by specifying a time profile of at least one parameter.

[0026] In further design variants, it is provided that two different materials are applied, one of which is the tough-elastic material.

[0027] In one embodiment, it is provided that two different compound materials are applied, one being the tough-elastic material and the other a softer material, for example a standard compound material commonly used in the art.

[0028] In one embodiment, it is provided that two different compound materials are applied, one being the tough-elastic material and the other being a non-elastic or rigid material.

[0029] The two materials mentioned are preferably present as adjacent ring-shaped areas on the lid.

[0030] Preferably, the rigid material is closer to the curl of the lid than the softer material.

[0031] In another variation, two different materials are applied one on top of the other in the same ring-shaped area. In one variation, an adhesion promoter is first applied to the lid, followed by the tough, elastic material. The adhesion promoter can be a lacquer. The adhesion promoter is present in a ring shape beneath the tough, elastic material and can be applied in addition to a full-surface lacquer coating of the lid.

[0032] In one design variant, the continuous coating of paint in the area of ​​the tough-elastic material can be interrupted, for example by not applying any coating there or by at least partially removing the paint applied there.

[0033] A can sealed with at least one, in particular two, physical sealing elements can be filled with a freely selectable medium, for example a liquid, an aerosol, a foodstuff, a beverage or animal feed.

[0034] Preferably, the medium is one that is under pressure or can develop pressure during storage or transport, such as a carbonated beverage.

[0035] The invention is illustrated by drawings:

[0036] Fig. 1: illustrates a closure element of a can according to the prior art.

[0037] Fig. 2: illustrates a first variant of a physical locking element.

[0038] Fig. 3: illustrates a second variant of a physical locking element.

[0039] Fig. 4: illustrates a third variant of a physical locking element.

[0040] Fig. 5: illustrates a fourth variant of a physical locking element.

[0041] Fig. 6: illustrates a physical closure element and a can casing before closing.

[0042] Fig. 7: illustrates a physical closure element of the first variant and a can casing according to the

[0043] Closing. Fig. 8: illustrates a physical closing element of the second variant and a can shell after closing.

[0044] Fig. 9: illustrates a physical closure element and a can shell after closing, showing layers of the can shell.

[0045] Figure 1 illustrates a closure element 1 of a can in the form of a bottom or lid element according to the prior art. Figures 2-6 illustrate the closure element 1 in question.

[0046] With regard to the shape and size of the bottom and lid elements, the closure element 1 in question can be a standard bottom or lid used to close conventional aluminum cans, so that it can be assembled with the same machines. The shape and size of the closure element 1 in question can therefore correspond to that of a known closure element 1.

[0047] The closure element 1 of the prior art is made of aluminum and has a radially projecting edge region 4, i.e., a region that extends beyond the diameter of the can body to be closed. The edge region 4 is typically an annular surface that is parallel to the disc-shaped base element 6 of the closure element 1. Between the edge region 4 and the base element 6, there is a shoulder 3 that slopes inwards from the edge region 4 towards the base element 6. Between the shoulder 3 and the base element 6, there may be an inner ridge that, viewed from the outside, forms a groove encircling the base element 6. In one embodiment, the base element 6 may have additional beads or additional circumferential grooves, similar to what is known in the field of tin cans with rolled-in stabilizing grooves.At the outer end of the edge area 4 there is a so-called curl 5, which is the outermost downward curvature of the edge of the closure element 1 .

[0048] The closure element 1 according to the prior art typically comprises a compound material 2. The compound material

[0049] Compound 2 is a sealing material applied to the edge region 4. The compound material 2 is located in the area of ​​the horizontal edge region 4. According to the prior art, as illustrated in Fig. 1, the compound material 2 can extend from the inside of the curl 5 over the entire edge region 4 and partially over the shoulder 3 of the closure element 1. It is known according to the prior art to apply the compound material 2 to the edge region 4 in a carousel in at least two revolutions, with the application taking place in the trough formed by the edge region 4, the curl 5, and the shoulder 3, so that in addition to the base in the form of the edge region 4, the side walls in the form of the curl 5 and the shoulder 3 are also provided with compound 2. The height of the application on the curl 5 and the shoulder 3 is approximately the same.According to the state of the art, it is also known to apply a hot melt as a compound material 2, which only flows into the required position and shape after heating.

[0050] Figures 2, 3, 4, and 5 illustrate various embodiments of the closure element 1. A comparison with Figure 1 clearly shows the difference from the prior art. The shoulder forms a transition to the edge region 4.

[0051] 3 a rounded section 7. In the present closure element 1, a tough-elastic material 8 is applied to a partial area of ​​the shoulder 3. In a first embodiment, the tough-elastic material 8 can be present exclusively in the area of ​​the rounded section 7 of the shoulder 3, as illustrated in Fig. 2. In a second embodiment, the tough-elastic material 8 can be present exclusively in a partial area of ​​the frustoconical wall of the shoulder 3, which adjoins the rounded section 7, as illustrated in Fig. 3. In a third embodiment, the tough-elastic material 8 can be present partially in the area of ​​the rounded section 7 and partially in the area of ​​the frustoconical wall of the shoulder 3, as illustrated in Fig. 4.

[0052] The tough-elastic material is therefore located in the area of ​​the curve 7 between the edge area 4 and the frustoconical wall of the shoulder 3 and / or on the frustoconical wall following the curve 7.

[0053] In one variant, the sub-area is provided to be made up of three areas of approximately equal width, one area being the curve 7 and the other two areas adjoining the curve 7 on both sides, as illustrated not to scale in Fig. 5.

[0054] The application in the area which adjoins the curve 7 towards the edge area 4 is not intentional, but results from the flow of the applied substance, which hardens into the tough-elastic material 8 through drying.

[0055] The substance is therefore preferably not applied in the area of ​​the edge region 4, but may flow into it. The extent of the flow is preferably at most equal to the width of the rounding 7.

[0056] A material is considered tough-elastic if it can be pulled or pushed and returns to its original shape after the force is applied.

[0057] In one version, the tough-elastic material is ethylene vinyl acetate (EVA). Another name is ethylene-vinyl acetate copolymer (EVAC).

[0058] The vinyl acetate content of the material is preferably at least 2%.

[0059] The vinyl acetate content of the material is preferably a maximum of 65%. The vinyl acetate content of the material is particularly preferably a maximum of 10%.

[0060] The tough-elastic material 8 is applied in one embodiment as a flowable substance. The flowable substance is preferably viscous so that it remains as close as possible to the application site.

[0061] The tough-elastic material 8 is preferably applied as a serum-based substance, which hardens to form the tough-elastic material 8 upon drying.

[0062] The closure element 1 can be stored in a dryer after the application of the tough-elastic material 8, or it can be moved through a dryer in a continuous process. Preferably, the closure element 1 is moved through a drying tunnel after the application of the tough-elastic material 8. Drying can be carried out by induction drying.

[0063] The tough-elastic material 8 is preferably food-safe.

[0064] The tough-elastic material 8 is preferably heat-resistant in order to withstand pasteurization of the contents of the can.

[0065] The tough-elastic material 8 is preferably acid-resistant.

[0066] The amount of tough-elastic material 8 applied to each closure element 1 is preferably between 15 mg and 70 mg. The tough-elastic material 8 is preferably not a hot melt or is not used as such, since the application of the closure element 1 preferably takes place in the cold state.

[0067] In one embodiment, the tough-elastic material 8 is cooled relative to the ambient temperature before the application of the closure element 1.

[0068] Preferably, the tough-elastic material 8 has a Shore D hardness value of less than 50 .

[0069] The tough-elastic material 8 is preferably a solid material.

[0070] In another variant, the tough-elastic material 8 is foamed.

[0071] The tough-elastic material 8 may contain additives.

[0072] In a first embodiment, the tough-elastic material 8 is applied to the already formed closure element 1 in the shoulder area 3. In a second embodiment, the tough-elastic material 8 is

[0073] The guide variant is applied to a flat blank, which is subsequently deformed into the closure element 1.

[0074] In a third embodiment, the tough-elastic material 8 is not attached to the closure element 1, but to the inside of the can shell 9, in particular to the curve of an outwardly projecting edge area 11 of the can shell 9. The tough-elastic material 8 is applied to the inner barrier layer 12 of the can shell 8.

[0075] The application on the closure element 1 or inside the can shell 9 is made at a point which, after the closure element 1 has been crimped to the can shell 9, is located at the outer end of the can shell 9 in the longitudinal direction of the can and / or is located between the can shell 9 and the shoulder of the attached closure element 1.

[0076] Figure 6 schematically illustrates the can body 9 and a closure element 1 to be attached to it. Neither the can body 9 nor the closure element 1 are shown to scale or in correct size relation to each other. The tough-elastic material 8, which is shown at the curve 7, could also be located opposite it on the outwardly projecting edge region 11 of the can body 9, or below the outwardly projecting edge region 11 on the cylindrical section of the inner wall of the can body 9. When the can body 9 is crimped with the closure element 1, the outwardly projecting edge region 11 is enclosed by the curl 5 and the edge region 4 and deformed downwards and towards the cylindrical section of the can body 9.

[0077] The already crimped edge area of ​​the finished can is illustrated in Figs. 7 to 9.

[0078] In the first variant illustrated in Fig. 7, the tough-elastic material 8 is located in the finished can in the straight extension of the can body 9, between the can body 9 and the closure element 1. In the second variant illustrated in Fig. 8, the tough-elastic material 8 is located in the finished can between the can body 9 and the shoulder 3 of the closure element 1. A third variant is a combination of the two variants, such that the tough-elastic material 8 is present in both areas, or, in other words, at least partially in the area between the can body 9 and the shoulder 3 of the closure element 1, and at least partially in the area which, in the finished can, is located in the straight extension of the can body 9 between the can body 9 and the closure element 1. The thickness D of the tough-elastic material 8 is preferably at least 0.03 mm, more preferably at least 0.08 mm.The thickness is defined as the maximum extent of the tough-elastic material 8 between the can shell 9 and the closure element 1. The length of the tough-elastic material 8 is its extension parallel to the walls of the can shell 9 and the closure element 1.

[0079] The application of the tough-elastic material 8 preferably takes place at a location separate from the filling system, where at least the second of the two closure elements 1 of a can is attached. The first closure element 1 can be attached in the filling system before filling. Alternatively, the first closure element 1 can be attached before the can reaches the filling system.

[0080] The tough-elastic material 8 is preferably non-adhesive or only weakly adhesive. Since the closure elements 1 are generally transported and fed to the crimping device in stacked form, this prevents the closure elements 1 from sticking to one another. Applying the tough-elastic material 8 below the bearing height of the stacked closure elements 1, which is limited by the curl 5, can also prevent sticking.

[0081] The tough-elastic material 8 can be applied by a needle system in which one or more needles apply the material in a ring shape around the shoulder 3. The needles or other application nozzles can be combined with a material removal device, which cleans the tough-elastic material 8 from the needles or other application nozzles. This cleaning can take place at a predefined interval, for example, at time intervals or at intervals based on the number of units produced, such as every 10,000 units.

[0082] In another embodiment, the tough-elastic material 8 can be pulled over the shoulder 3 in the form of a band-shaped ring, so that it adheres to the shoulder 3 and is held there by the tough-elastic forces.

[0083] The can casing 9 can be made of coated metal, such as tinplate or aluminum.

[0084] In a preferred embodiment, the can shell 9 is formed from composite material, wherein the can shell 9 comprises an inner moisture-resistant barrier layer 12 and at least one further layer 14 made of paper or cardboard material. As illustrated in Fig. 9, the can shell 9 preferably comprises an inner barrier layer 12, an outer barrier layer 13, and at least two intermediate layers 14 made of paper or cardboard material. The inner barrier layer 12 can be a laminate consisting of one or more film layers and a paper layer, with the one or more film layers facing the interior of the can. As illustrated, the outer barrier layer 13 can be folded over the cut edge of the middle layers and overlap the inner barrier layer 12. The inner barrier layer 12 preferably has a sealing seam extending longitudinally along the can, for example, a fold seam with itself.Layers 12 and 13 of the can shell 9 are preferably wound, in particular longitudinally wound, such that each layer has a longitudinally extending gap, a butt joint, or an overlap area with itself. The outer barrier layer can also be wound or drawn over the underlying layers in the form of a sheath. The position of the tough-elastic material 8 can be arranged according to one of the three variants described with reference to Figures 7 and 8.

[0085] Suitable layer structures are known from previous applications of the applicant and can be found in WO2018224658A2 and WO2022219176A1, the disclosures of which are hereby incorporated by reference. However, the layer structure in question is not limited to the layer structures described therein.

Claims

Patent claims 1. Closure element (1) of a can, which closure element (1) in the inapplied state comprises a base element (6), a shoulder (3), an annular edge region (4), and a curl (5), wherein the shoulder (3) includes a curve (7) with which the shoulder (3) transitions into the edge region (4), wherein the shoulder (3) connects the edge region (4) and the base element (6), and the curl (5) adjoins the outer edge region (4), characterized in that the closure element (1) has an annular coating of a tough-elastic material (8) in a partial region of the shoulder (3), wherein the partial region is limited exclusively to the curve (7), or the partial region is limited exclusively to a partial region of a truncated conical wall of the shoulder (3), or the partial region is limited exclusively to the curve (7) and a partial region of a truncated conical wall of the shoulder (3), or the partial region is composed of three regions of approximately equal width, wherein one region comprises the curve (7) and the two other areas connect to the rounding (7) on both sides.

2. Closure element (1) according to claim 1, characterized in that the tough-elastic material (8) is present exclusively in the area of ​​the rounding (7) and / or on the frustoconical wall following the rounding (7).

3. Closure element (1) according to one of claims 1 to 2, characterized in that the tough-elastic material (8) comprises ethylene vinyl acetate.

4. Closure element (1) according to one of claims 1 to 3, characterized in that the application quantity of the tough-elastic material (8) per closure element (1) is between 15 mg and 70 mg.

5. Closure element (1) according to one of claims 1 to 4, characterized in that it is attached to a can with a can shell (9) made of composite material, which can shell (9) comprises an inner moisture-resistant barrier layer (12) and at least one further layer (14) made of paper or cardboard material.

6. Can with a can shell (9) which is closed at both ends with a closure element (1) wherein the respective end of the can shell (9) is crimped with the closure element (1), characterized in that a tough-elastic material (8) is present between the can shell (9) and the closure element (1), either exclusively in the annular area which, viewed in the longitudinal direction of the can, is located between the outer end of the can shell (9) and the outer end of the closure element (1), or exclusively in an annular area between the can shell (9) and a shoulder (3) of the closure element (1), or exclusively in these two areas.

7. Can according to claim 6, characterized in that the thickness (D) of the tough-elastic material (8) between the can shell (9) and the closure element (1) is at least 0.03 mm, preferably at least 0.08 mm.

8. Can according to claim 6 or 7, characterized in that it is closed with at least one closure element (1) according to one of claims 1 to 5.

9. Can according to one of claims 6 to 8, characterized in that the can shell (9) consists of composite material, wherein the latter comprises an inner moisture-resistant barrier layer (12) and at least one further layer (14) of paper or cardboard material.

10. Method for closing a can with a closure element (1), the can having a can shell (9), characterized in that in a first step a tough-elastic material (8) is applied to a limited annular area of ​​the closure element (1), or of a blank of the closure element (1) with subsequent forming, or of the can shell (9), in a second step an end of the can shell (9) is crimped with the closure element (1), wherein after crimping the tough-elastic material (8) is present in an annular area between the can shell (9) and the shoulder (3) of the closure element (1) and / or in that annular area which, viewed in the longitudinal direction of the can, is located between the outer end of the can shell (9) and the outer end of the closure element (1).

11. Method according to claim 10, characterized in that the crimping of the can shell (9) with the closure element (1) is carried out without heating the closure element (1), i.e. without thermal softening of the tough-elastic material (8) .

12. Method according to claim 10 or 11, characterized in that the can has a can shell (9) made of composite material, which comprises an inner moisture-resistant barrier layer (12) and at least one further layer (14) made of paper or cardboard material.

13. Method according to one of claims 10 to 12, characterized in that in the first step the tough-elastic material (8) is applied as a ring-shaped bead.

14. Method according to one of claims 10 to 13, characterized in that in the first step a water-based substance is applied which hardens to form a tough-elastic material (8) by drying.

15. Method according to any one of claims 10 to 14, characterized in that the tough-elastic material (8) comprises ethylene vinyl acetate.

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