EP3837063A1

EP3837063A1 - Can packaging, can packaging blank and apparatus and method for production thereof

Info

Publication number: EP3837063A1
Application number: EP19752178.4A
Authority: EP
Inventors: Stephan Ebner; Gustav-Konstantin GROSS
Original assignee: Linhardt GmbH and Co KG
Current assignee: Linhardt GmbH and Co KG
Priority date: 2018-08-17
Filing date: 2019-08-07
Publication date: 2021-06-23
Anticipated expiration: 2039-08-07
Also published as: WO2020035367A1; EP3837063C0; DE102018120091A1; CA3109743A1; EP3837063B1; CA3109743C; US20210170464A1

Abstract

The invention relates to an apparatus (1) for producing a can packaging blank (10) by backward extrusion. The apparatus has a die (2) and an extrusion punch (3), wherein the die (2) has a die base (2.1) and a die wall (2.2) having a die wall height HG. The die wall (2.2) has, in the region thereof adjacent to the die base (2.1), at least one protrusion (4) having predetermined width (B), predetermined height (H), predetermined depth (T) and predetermined cross-section, wherein the height (H) of the protrusion (4) equals 95% of the die wall height (HG) at maximum.

Description

Can packaging, can packaging blank and device and method for their production

Technical field

The invention relates to a can packaging, a can packaging blank and an apparatus and a method for the production thereof.

State of the art

Can packaging is often formed from blanks, which by a

Extrusion processes were made. An extrusion process is a forming process in which the forming of a workpiece by a

Pressure is applied. The direction of flow of the material relative to

The direction of stamp movement provides the basis for distinguishing between

Forward extrusion (material flow and punch movement direction are the same), backward extrusion (material flow and punch movement direction are

opposite) and cross extrusion (material flow across to

Star direction of movement).

The production of a thin-walled metal tube by backward extrusion is described in DE 29 32 016 C2. DE 197 08 826 A1 describes a can

thin-walled sheet metal, consisting of a one-piece base part produced by extrusion, an adjoining, tubular middle part and a located on the side of the middle part opposite the bottom part, with the

Central part of the lid connected by flanging. The bottom part has ribs, beads or the like, which are introduced into the bottom part in the course of the extrusion process when the bottom part is produced with the middle part. In connection with can packaging, there is often a desire to make it not only visually but also haptically characteristic and distinguishable from one another. This is usually achieved by a deformation or shaping treatment of the can packaging blank or the can packaging. However, the problem arises that with every deformation of the outer surface there is a corresponding deformation of the inner surface and thus of the interior of the can container. A circumferential waist of the can, for example, has the consequence that the

The interior of the can is initially tapered and then expanded again towards the bottom of the can. As a result, there is on the one hand an interior space which is reduced in comparison to the untapped cylindrical box. On the other hand, problems arise when filling the can packaging, which can only be done with lower pressures and thus more time. Problems also arise when emptying the can packaging, since any shape deviating from a smooth, continuous inner surface promotes the remaining fill goods and makes them more likely.

There is therefore still a need for can packaging which has a haptically distinguishable outer surface and at the same time can be filled easily and quickly and is to be emptied with as little residue as possible.

Presentation of the invention

The object of the present invention is to provide a can packaging which has a haptically distinguishable outer surface and at the same time can be filled easily and quickly and can be emptied with as little residue as possible. This object is achieved according to the invention by the device for producing a can packaging blank according to independent claim 1, by the method for producing a can packaging blank according to independent claim 10, by the can packaging blank according to independent claims 13, 17 and 18 and the can packaging according to independent claim 19. Further advantageous aspects, details and refinements of the invention result from the dependent claims, the description and the drawings. The present invention provides a device for producing a

Can packaging blanks available through backward extrusion. The device has a die and a press die, the die having a die bottom and a die wall with a die wall height. The die wall has in its area adjacent to the die bottom at least one projection with a predetermined width, predetermined fleas, predetermined depth and predetermined

Cross-section, the fleas of the protrusion being a maximum of 95% of the die wall height.

The projection provided in the area of the die wall adjacent to the die bottom allows a haptically perceptible design the outside of the wall of a can packaging blank or the can packaging produced from this blank without the inner surface of the wall of the can packaging blank or the can packaging being changed. The structuring of the outer surface, that is to say the outside of the wall of the can packaging blank, does not take place, as is known from the prior art, by subsequent deformation, but during the manufacturing process when the can packaging is created. In all subsequent deformation steps, the wall of the can packaging is dented, notched, bulged or otherwise changed while maintaining the previously formed wall thickness. Common to all deformation steps is the fact that the deformation visible on the outside becomes visible as a negative on the inside. If the can wall is dented, the corresponding area appears on the outer surface as a depression and on the inner surface as an elevation. Conversely, the same applies: if the can wall is dented, an elevation appears on the outside, which corresponds to a depression on the inside of the wall of the can packaging.

In contrast to this, the structuring of the outside of the wall brought about by the device according to the invention for producing a can packaging blank takes place directly during the production process by backward extrusion through a variation in the wall thickness of the can packaging blank. The one in the

In the area of the projection, the backward-flowing metal has a recess in the wall of the wall that is formed in accordance with the shape of the projection

Can packaging blanks arise. The simplest example is a point-like tip with a height of 0.1 mm as a projection on the die wall. This tip leaves a groove 0.1 mm deep in the flowing metal that forms the wall. This depression visible on the outside, however, has no equivalent in the form of an increase on the inside of the can wall. This remains smooth and continuous as with a can packaging without structuring the outside.

Based on this basic idea of a head start in the form of a tip, there are almost any number of possible variations. First, the number of projections and their distribution over the circumference of the die wall can be varied. Thus, the outside of the wall can be designed, for example, in the form of two grooves arranged closely next to one another, but can also be designed as a plurality of grooves distributed in any way over the circumference of the can packaging. The shape of the projection as well as its width, height, depth and cross section can also be varied. In this way, virtually any number of relief-like depressions can be created in the wall of the can packaging that are visible on the outside. For example, a projection with a semicircular cross section with a radius of 1 mm creates a semicircular depression with a maximum depth of 0.5 mm in the wall of the can packaging. A projection with a triangular cross section, the base of which is arranged on the die wall and has a width of 2 mm and whose height, for example, is 1 mm from the base to the tip of the triangle, leaves a corresponding depression in the wall of the can packaging.

Already these few examples mentioned, which are explained in more detail below in connection with the preferred embodiments of the invention, show the extreme variety of design options that are provided by the invention

Device are created.

Another possible variation results from coordinating the height of the projection and the thickness of the round blank used to produce the can packaging. A depression in the wall of the can packaging is only formed over the portion of the can packaging that is formed from the section of the round blank that comes into contact with the respective projection. If, for example, the projection measured from the bottom of the die has a height of 1 mm along the die wall and if a blank with a thickness of 2 mm is used to form the can packaging blank, the groove formed by the projection extends over 50% of the starting from the bottom of the can packaging blank vertical extension of the

Canned packaging blank. If the round blank has a thickness of 4 mm, the groove extends accordingly only over 25% of the vertical extension of the

Canned packaging blank. The reason for this is that the material of 3 mm of the blank thickness does not come into contact with the projection at all, and therefore cannot form a corresponding depression.

If one were to use a 1 mm thick blank for a 1 mm high projection, the recess would extend in the longitudinal direction over the entire extent of the can packaging blank. However, this is not desirable since depressions in the region of the open end of the can facing away from the bottom of the can packaging blank

Can packaging blanks are associated with significant disadvantages. As is known to the person skilled in the art, a can packaging blank is provided with a tapering shoulder and a rolled edge at its open end in the course of its further processing into a can packaging. The rolled edge is used for the subsequent attachment of a

Sealing cap, a dosing device or another, arbitrarily designed applicator. However, a tight connection between the cap and is imperative Can packaging because it must be prevented that the filling material escapes unintentionally. Such a tight connection can only in the case of a smooth outside of the wall of the can packaging blank in the to form shoulder and rolled edge

provided area.

In all embodiments of the present invention, the predetermined flea of a projection corresponds to the maximum extent of the projection in a direction parallel to the die wall. The fleas of a projection can of course vary over the width and also over the depth of the projection. However, the statement that the fleas of a certain projection correspond to the maximum extension of the projection in a direction parallel to the die wall means that the fleas are clearly defined.

According to the invention, the fleas of the projection provided in the region of the die wall adjacent to the die floor or the fleas of the provided ones

Protrusions maximum 95% of the die wall height. This limitation ensures that the area of the can packaging blank, which is provided for forming the shoulder and the rolled edge of the can packaging, has no recess or relief-like structure on the outside of its wall. The smooth, continuously running outer surface in this area ensures a tight connection between the cap and the can packaging.

It should be noted that a strictly defined groove is a surface imperfection that is a linear depression with a rounded or flat bottom. In contrast, a crack has a sharp base and grooves are created by the ideal geometric shape of the tool cutting edge.

As already stated, the different shape of the

An extremely large variety of depressions on the outside of the can packaging blank, which are referred to as a “relief-like configuration” of this outside, are produced in the die wall or the projections provided there

In the context of the present text, the wall of the can packaging blank is referred to as "striations", regardless of its specific configuration and regardless of the definitions cited above. The die wall preferably has several projections in its area adjacent to the die bottom. As already stated, this embodiment increases the Possibilities of variation in the design of the structure of the outside of the

Can packaging blanks and a can packaging made therefrom clearly. It should be made clear that there are a number across the circumference of the die wall of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,

27, 28, 29, 30, .... projections can be provided.

If several projections are provided, any number of projections can have the same width, height, depth and cross section, while another group of projections can also have the same width, height, depth and cross section, but which differ from those of the first group. It is also possible for all the projections to have different widths and / or different heights and / or different depths and / or different cross sections. In principle, any combination of projections can be selected, each of which has a specific width, height, depth and cross section. However, the height of each of the projections provided in the area of the die wall adjacent to the die bottom may not exceed 95% of the die wall height. The width of a particular protrusion in all embodiments of the present invention corresponds to the maximum extension of the protrusion in a direction parallel to the die bottom. Since the die wall generally has a curvature in a plane parallel to the die bottom and it can be advantageous to equip the projection with the same curvature, the width of the projection in these cases corresponds to the length of a curve corresponding to the curvature of the die wall

Line. It is clear to the person skilled in the art that there are basically infinitely many directions parallel to the die bottom, and also that a certain projection can be described by a large number of the curved lines mentioned, by stating that the width of a certain projection corresponds to the maximum extension of the projection, this width is clearly defined. The maximum width can also be specified in the case of an arbitrarily shaped projection which varies in width over its height.

The height of a particular projection corresponds in all embodiments of the present invention to the maximum extension of the projection in a direction parallel to the die wall. The height of a projection can of course vary over the width and also over the depth of the projection. However, by stating that the height of a certain projection corresponds to the maximum extension of the projection in a direction parallel to the die wall, this height is clearly defined.

In all embodiments of the present invention, the depth of a specific projection corresponds to the maximum extension of the projection in a direction perpendicular to the die wall. The depth of a projection can of course vary over the width and also over the height of the projection. By saying that the depth of a particular protrusion is the maximum extension of the protrusion in one Corresponds to the direction perpendicular to the die wall, this depth is clearly defined.

In principle, the projections or a single projection can have any width, which is only limited by the circumference of the can packaging blank produced with the aid of the die. The width of a projection can be, for example, a quarter, a third or even half the circumference of the

Can packaging blanks amount. The projections preferably have a width of 0.1 mm to 10 mm, particularly preferably 0.5 mm to 5 mm and particularly preferably 1 mm to 2.5 mm. If several projections are provided, any number of projections can have an identical first width, which is for example in the range between 1.5 mm and 2 mm, while another group of

Projections can have an identical second width, which differs from the first width and is for example in the range between 2 mm and 2.5 mm. In this embodiment, the two groups of projections and thus also the two groups of grooves in the wall of the can packaging can be formed opposite one another as sections with grooves of the same width in each case.

However, alternating grooves of different widths can follow one another. It is also possible for all the projections to have different widths. In principle, any combination of projections can be selected, each of which has a specific width. It is obvious to the person skilled in the art that simply because of the variation in the width of the projections there is an almost infinite variety for a relief-like design of the outside of the

Can packaging blank and the can packaging made from it opens. The number of groups of grooves of the same width is only due to the size of the

Can packaging limited.

The projections preferably have a height of 0.1 mm to 30 mm, particularly preferably 0.5 mm to 10 mm and particularly preferably 1 mm to 5 mm. If several projections are provided, any number of projections can have an identical first height, which is, for example, in the range between 2 mm and 3.5 mm, while another group of projections can have an identical second height, which, however, differs from that first height differs and is, for example, in the range between 3.5 mm and 4.5 mm. Because a certain

Can packaging blank from a certain blank, which has a certain thickness, is produced by projections of different heights in the wall of the can packaging blank grooves of different lengths in the longitudinal direction of the can packaging blank. In this embodiment, the aforementioned two groups of projections and thus the two groups of grooves in the wall of the can packaging can be opposite one another as sections with grooves of each be of the same length. But alternating scoring can also be done

of different lengths follow each other. It is also possible for all the projections to have different heights. Basically, any

Combination of projections can be chosen, each of which has a certain height for itself. It is obvious to a person skilled in the art that the variation of the height of the projections alone results in an almost infinite variety for a relief-like design of the can packaging blank and the can packaging produced therefrom. The number of groups of grooves of the same height is only limited by the size of the can packaging. The height of the protrusions can also be varied continuously according to a certain pattern, whereby, for example, grooves of different lengths are produced around the entire circumference of the can packaging blank or the can packaging, which in their sequence simulate a wave pattern, for example.

The projections preferably have a depth of 0.01 mm to 1 mm, particularly preferably from 0.05 mm to 0.5 mm and particularly preferably from 0.1 mm to 0.25 mm. If a plurality of projections are provided, any number of projections can have an identical first depth, which is, for example, in the range between 0.15 mm and 0.2 mm, while another group of projections can have an identical second depth, which however is different differs from the first depth and is, for example, in the range between 0.2 mm and 0.25 mm. In this embodiment, the two groups of projections and thus also the two groups of grooves in the wall of the can packaging opposite one another can be formed as sections with grooves of the same depth in each case. But alternately, grooves of different depths can follow one another. It is also possible that all

Projections have different depths. Basically, any

Combination of projections can be chosen, each of which has a specific depth. It is obvious to the person skilled in the art that simply because of the variation in the depth of the projections there is an almost infinite variety for a relief-like one

Design of the can packaging blank and the can packaging made from it opens. The number of groups of grooves of the same depth is only limited by the size of the can packaging.

The projections provided in the area of the die wall adjacent to the die bottom have a cross section parallel to the die bottom, the

Cross-section preferably triangular, quadrangular, in particular trapezoidal,

is circular segment-shaped, in particular semicircular. In principle, the cross section of the protrusions can be chosen practically arbitrarily within limits which are obvious to the person skilled in the art and are technically determined. The above-mentioned cross sections result in grooves of a haptically and optically particularly demanding form and are therefore preferred in the context of the present invention. The projections are preferably circumferential over the entire circumference of the

Die wall arranged. In this embodiment, a haptically and optically similar or even identical impression results over the entire circumference of the can packaging blank produced with the aid of the die and the can packaging produced therefrom. However, it can also be preferred for other purposes to concentrate the projections in a specific partial area of the die wall and thus the grooves in a specific partial area of the can packaging blank or the can packaging.

The press stamp preferably has a circumferential bead in its edge region adjacent to the die base in the state of use. Due to the gap remaining between the bead and the die wall, the thickness of the wall of the

Can packaging blanks defined. In the area of a ledge

Die wall defines the gap remaining between the bead and the projection the thickness of the wall of the can packaging blank in the area of a groove.

The can packaging blank and also the can packaging produced therefrom can in principle have a horizontal cross section which is practically arbitrarily chosen within limits which are obvious to the person skilled in the art and are technically determined. This

Cross section corresponds to the cross section of the die wall parallel to the die bottom. Can packaging blanks very often have the shape of a hollow, vertical circular cylinder. According to a preferred embodiment of the present

Invention therefore forms the die bottom with the die wall a hollow, vertical circular cylinder. The diameter of this circular cylinder parallel to

Die bottom is preferably between 10 mm and 120 mm. An oval cross-section of the can packaging blank parallel to the die bottom is also easy to implement and visually appealing. The same applies to a rectangular, square, triangular or generally polygonal cross section. However, it should be emphasized again that in principle every conceivable cross-sectional shape is possible.

The present invention also includes a method of making a

Can packaging blank by backward extrusion comprising the steps a) providing a device for producing a can packaging blank by backward extrusion with die and press die as described above, b) inserting a round blank into the die,

c) inserting the press stamp and exerting a pressing pressure on the circular blank, d) removing the can packaging blank from the die. All of the advantages and special features mentioned in connection with the various embodiments of the device according to the invention for producing a can packaging blank by backward extrusion also apply to the method according to the invention for producing a

Can packaging blanks by back extrusion. To avoid repetition, reference is made to the corresponding explanations above.

The diameter of the circular blank is preferably selected such that the circular blank lies on the projections in its edge region after insertion into the die before the press ram is inserted. The punch is then inserted into the die and exerts pressure on the blank. The blank material is then first pressed down to the die bottom and is then in contact with these projections via the height H of the projections. According to a particularly preferred embodiment, the

Projections provided adjacent region of the die wall to a predetermined height, the predetermined height being a maximum of 95% of the thickness of the round blank. Particularly preferred are embodiments in which the projections provided in the area of the die wall adjacent to the die bottom have a predetermined height, the predetermined height being at most 75%, particularly preferably at most 50%, of the thickness of the round blank. In addition, are preferred

Embodiments in which the projections provided in the area of the die wall adjacent to the die bottom have a predetermined height, the predetermined height being at least 5%, preferably at least 15%, particularly preferably at least 25% of the thickness of the round blank.

It should be clarified that the preferred embodiments described here relate to advantageous variants of a method for producing a can packaging blank by back extrusion, which is carried out using a device for producing a can packaging blank by back extrusion with a die and press die as described above. The limitation provided according to the invention, according to which the height of the projection provided in the area of the die wall adjacent to the die bottom or the height of the projections provided is a maximum of 95% of the die wall height, is thus in any case also observed when the method for producing a can packaging blank is carried out by backward extrusion , As already stated, this limitation ensures that the area of the can packaging blank, which is provided for forming the shoulder and the rolled edge of the can packaging, has no recess or relief-like structure on the outside of its wall. Due to the smooth, continuously running outside, a tight connection of Cap and can packaging are ensured. In practice, however, it is often easier to set the height of the projections in relation to the thickness of the round blank used. As a result, it can be determined quickly and easily in what range the thickness of a round blank may be that is to be used in a specific die equipped with a plurality of specifically designed projections of a predetermined height.

As already stated, there is a possibility of varying the shape of the grooves in the can packaging blank by coordinating the height of the protrusion or the protrusions and the thickness of the round blank used to produce the can packaging. The relief-like structure in the wall of the

Can packaging blanks only form over the sub-area of the

Can packaging blank, which is formed from the portion of the blank that comes into contact with the projections. If, for example, the projection measured from the bottom of the die has a height of 2 mm along the die wall and if a blank with a thickness of 3 mm is used to form the can packaging blank, the groove formed by the projection extends from the bottom of the

Can packaging more than 66% of the vertical dimension of the can packaging. If the round blank has a thickness of 4 mm, the groove extends correspondingly only over 50% of the vertical extent of the can packaging. The reason for this is that the material of 2 mm of the blank thickness does not come into contact with the projections at all, and therefore cannot form a corresponding recess.

If one were to use a round blank with a thickness corresponding to the height of the projections or even a smaller thickness, then the would in the wall of the

Can packaging formed grooves always over the entire extent of the

Stretch the can packaging lengthways. As already stated, such embodiments are associated with disadvantages and are not desirable. According to a further preferred embodiment, the

inventive method or that together with the inventive

Device used round plate made of metal, in particular aluminum, one

Aluminum alloy or copper. Backward extrusion processes can be carried out particularly well and advantageously with suitable metals known to the person skilled in the art.

Aluminum and copper are particularly suitable and aluminum is particularly preferred. Of course, any type of suitable metal alloy, in particular aluminum alloy, known to the person skilled in the art can also be used. The choice of the material for the round blank is made in a conventional manner by the person skilled in the art depending on the properties desired for the finished can packaging. The present invention also includes a can packaging blank with a main axis defining a longitudinal direction and a wall having an outside and an inside. The wall of the can packaging blank has a variable wall thickness at least over a portion of the can packaging blank that extends in the longitudinal direction. The section of the can packaging blank with variable wall thickness extends from the bottom of the

Can packaging blanks over a maximum of 95% of the height in the longitudinal direction of the

Canned packaging blank. The variable wall thickness is caused by the fact that only the outside of the wall is designed in relief.

According to the invention, the portion of the can packaging blank with a variable wall thickness extends from the bottom of the can packaging blank over a maximum of 95% of the height in the longitudinal direction of the can packaging blank. As already in connection with the device and the method according to the present

According to the invention, this limitation ensures that the area of the can packaging blank, which is intended for the subsequent formation of the shoulder and the rolled edge of the can packaging, has no recess or relief-like structure on the outside of its wall. The smooth, continuously running outer surface in this area ensures a tight connection between the cap and the can packaging.

As already stated, the very fundamental advantage of the

Method according to the invention and the device according to the invention in that, in contrast to the can packaging known from the prior art with a structured outer surface, the packaging provided by the device according to the invention

Production of a can packaging blank brought about structuring of the outer surface directly during the production process by backward extrusion through a variation in the wall thickness of the can packaging blank. The projection provided in the area of the die wall adjacent to the die bottom has the effect that in the area of the projection the backward flowing metal causes a recess in the wall of the can packaging blank which is formed, corresponding to the shape of the projection. However, such a depression, which is visible on the outside of the can packaging blank, has no equivalent in the form of an increase on the inside of the wall of the can packaging blank. This remains smooth and continuous as with a can packaging without structuring the outside. So there will be can packaging blanks and below

Can packaging formed which has a discontinuous or variable wall thickness in its cross-sectional area at least over a longitudinally extending partial area, the variable wall thickness being caused by the fact that only the outside of the wall is designed in relief. Such Can packaging or can packaging blanks, regardless of the method used to manufacture them, are not known from the prior art.

It should be emphasized again that the variable wall thickness is caused by the fact that only the outside of the wall is designed in relief. The

On the other hand, the inside of the wall of the can packaging blank remains unchanged, that is, it is smooth and continuous, like a can packaging without

Structuring the outside. This applies regardless of the cross-sectional area of the can packaging blank. As already stated, the die bottom can be circular, oval, rectangular, square, triangular or polygonal, the

Die wall is arranged vertically on the die bottom. This means that the cross section of the die parallel to the die bottom can also have a circular, oval, rectangular, square, triangular or polygonal shape. It is clear to the person skilled in the art that with the aid of such devices, can packaging blanks can be produced in an analogous variety of shapes. A cross-sectional area of the can arranged perpendicular to the main axis HA of the can packaging blank

Can packaging blanks can accordingly not only have a circular shape, but also an oval, rectangular, square, triangular or polygonal shape. Common to all the embodiments is the fact that the variable wall thickness is caused exclusively by a relief-like design of the outside of the wall. The statement that the inside of the wall of the can packaging blank is smooth and continuous means, for example in the case of a circular cross section, that the inside of the wall has a constant curvature. In the case of a square cross-section, the term “continuous” does not refer to the entire inside, since there can be no question of a “continuous” transition at the edges of the square. In this case, "smooth and continuous" or "steady" refers to each of the four inner surfaces of the square.

Generally speaking, the feature includes that "only the outside of the wall is designed in relief", at the same time the statement that there is no such relief-like design on the inside of the wall. There are therefore no depressions, ridges or other structures on the inside.

The portion of the can packaging blank with variable wall thickness preferably extends from the bottom of the can packaging blank to a maximum of 90%, preferably a maximum of 85%, particularly preferably a maximum of 80%, particularly preferably a maximum of 75% and very particularly preferably a maximum of 50% of the height in the longitudinal direction of the can packaging blank , Embodiments are also preferred in which the partial area of the

Can packaging blank with a variable wall thickness starting from the bottom of the can packaging blank extends over at least 5%, preferably at least 15%, particularly preferably at least 25% of the height in the longitudinal direction of the can packaging blank.

Are particularly preferred in the context of the present invention

Can packaging blanks whose relief-like design of the outside of the wall is caused by groove-like depressions in the outside. It should be mentioned again that in all cases the inside of the wall is continuous.

Particularly preferably, the groove-like depressions extending from the outer surface into the wall of the can packaging blank run parallel to the main axis (HA) of the can packaging blank.

The present invention also includes a can packaging blank that can be manufactured using one of the devices described above for producing a

Can packaging blanks by backward extrusion. The present invention also includes a can packaging blank that can be produced by one of the methods described above for producing a can packaging blank by back extrusion.

Finally, the present invention also includes a can packaging that can be produced using one of the can packaging blanks described above. Starting from a can packaging blank produced according to one embodiment of the present invention, all that is required to produce the finished can packaging is that the steps known to the person skilled in the art, such as, for example, the formation of the shoulder and the flanging of the opening of the can packaging blank facing away from the can packaging base to form a rolled edge.

Further developments, advantages and possible uses of the invention also result from the following description of exemplary embodiments and from the figures.

Brief description of the drawings

The invention will be explained in more detail below using exemplary embodiments in conjunction with the drawings. Show it Figure 1 is a schematic representation of a vertical section through a die known from the prior art.

Fig. 2 shows a schematic representation of a vertical section through a

Device according to the invention for the production of a

Can packaging blanks by back extrusion;

Fig. 3A in a schematic representation in side plan view of an inventive

die;

3B shows a schematic representation in plan view of a section of the die according to FIG. 3A;

Fig. 4A in a schematic representation in a side plan view

Can packaging blank according to the invention;

4B is a schematic illustration of an enlarged detail of a section along the plane A-A of FIG. 4A;

Fig. 5 in a schematic representation in a side plan view of an inventive

Can packaging produced from the can packaging blank according to FIG. 4A.

Ways of Carrying Out the Invention

FIG. 1 shows a schematic representation of a vertical section through a die 2 known from the prior art. The press ram 3, the die 2 with die bottom 2.1 and die wall 2.2 are shown. The press ram 3 has a circumferential bead 5.

In the left part of FIG. 1, the press ram 3 is shown spaced from the die 2, that is to say the situation before the can packaging blank is formed. The blank 6 is inserted into the die 2. In the right part of FIG. 1, the press ram 3 is inserted into the die 2 and exercises

Pressure on the round blank 6. As a result of this compressive stress, the round blank 6 is deformed and flows upward in the opposite direction to the punch movement. By the Between the circumferential bead 5 of the press ram 3 and the gap 2.2 remaining in the die wall, the wall thickness of the can of packaging blank formed by backward extrusion is defined. FIG. 2 shows a schematic representation of a vertical section through a device according to the invention for producing a can packaging blank by backward extrusion. The illustration is similar to the device shown in the left part of FIG. 1 and known from the prior art. The press ram 3, the die 2 with die bottom 2.1 and die wall 2.2 are shown. The press ram 3 has a circumferential bead 5. The die wall 2.2 has, in its area adjacent to the die bottom 2.1, a plurality of projections 4 with a width of 1 mm, a height H of 1.5 mm, a depth of 0.15 mm and a cross section which is trapezoidal in shape parallel to the die bottom 2.2. The blank 6 is inserted into the die 2. The blank 6 is made of aluminum and has a thickness HR of 4.5 mm. The height of the die wall HG is 6 mm. The height of the projections 4 is thus 25% of the height of the die wall. The blank 6 lies on the projections 4 before the press ram 3 is inserted. The press ram 3 is subsequently inserted into the die 2 and exerts pressure on the round blank 6. The blank material is then first pressed down to the die base 2.2 and is then in contact with the projections 4 over a height H of 1.5 mm. Since the thickness HR of the round blank is a factor 3 greater than the height H of the projections 4, the groove-like depressions in the wall of the pull through in this way

Backward extruding shaped can packaging blank over a third of the length of the can packaging blank in the longitudinal direction LR (see Figure 4A).

FIG. 3A shows a die 2 according to the present invention in a schematic illustration in a side plan view. The die 2 is shown with die bottom 2.1 and die wall 2.2. The die wall 2.2 has a plurality of projections 4 in its area adjacent to the die bottom 2.1. The projections 4 have a width B of 5 mm, a height H of 10 mm, a depth of 0.15 mm and a cross section which is trapezoidal in shape parallel to the die base 2.2. The one

The die base 2.1 adjacent edges of the projections 4 are chamfered, so they do not project perpendicularly from the die wall 2.1, but run at an angle of approximately 45 ° relative to the die wall 2.1.

The depth T of the projections 4 of 0.15 mm can be seen from the detail of the die according to FIG. 3A shown in a top view in a schematic illustration in FIG. 3B. All projections 4 of the embodiment of the die according to the invention shown in FIGS. 3A and 3B have the same height, width, depth and the same cross section and are equidistantly spaced apart and evenly distributed around the entire circumference of the die wall.

FIG. 4A shows a schematic illustration in a top view from the side

Can packaging blank 10 according to the invention. FIG. 4B shows a schematic illustration of an enlarged detail of the section along the plane A-A of FIG. 4A. The can packaging blank 10 has a main axis HA defining a longitudinal direction LR and a cross-sectional area arranged perpendicular to the main axis HA, the wall 12 of the can packaging blank 10 having an outside 12.1 and an inside 12.2. The wall 12 in FIG. 2 has a portion TB of the can packaging blank 10 that extends in the longitudinal direction LR

Cross-sectional area of the can packaging blank 10 a variable wall thickness WD, which is caused by groove-like depressions 11 in the outer surface 12.1, the inner surface 12.2 running continuously over the area of the groove-like depressions 11. The depth T of the groove-like depressions 11 corresponds to the depth T of the projections 4 of 0.15 mm (see FIG. 3B). The grooves 11 formed by the projections 4 of the die 2

Can packaging blanks 10 have the same height, width, depth and the same cross-section and are equidistantly spaced apart and evenly distributed around the entire circumference of the can packaging blank 10. FIG. 5 shows a schematic illustration in a top view from the side

Can packaging 20 according to the invention produced from the can packaging blank 10 according to FIG. 4A. Starting from the can packaging blank 10 according to FIG. 4A, only the post-processing known to the person skilled in the art of the opening of the can packaging blank 10 facing away from the can packaging base was carried out for producing the finished can packaging 20. This includes, for example, the formation of the can shoulder and the flanging of the can packaging wall at its opening to form the rolled edge 21. LIST OF REFERENCE NUMBERS

1 device

2 dies

2.1 die bottom

2.2 die wall

3 stamps

4 head start

5 bead

6 rounds

10 can packaging blank

11 groove-like depressions

12 wall

12.1 External surface of the wall

12.2 Inner surface of the wall

20 can packaging

21 bead

B protrusion width

H height of the projection

T depth of the projection

HG height of the die wall

HR thickness of the blank

HA main axis of the can packaging blank LR longitudinal direction

TB section of the can packaging blank WD wall thickness of the can packaging blank

Claims

claims

1. Device (1) for producing a can packaging blank (10) by

Backward extrusion, the device comprising a die (2) and a press ram

(3), the die (2) having a die base (2.1) and one

Die wall (2.2) with a die wall height (HG), characterized in that the die wall (2.2) in its area adjacent to the die bottom (2.1) has at least one projection (4) with a predetermined width (B), predetermined height (H), predetermined Depth (T) and predetermined cross section, the height (H) of the projection (4) maximum 95% of

Die wall height (HG).

2. Device (1) according to claim 1, characterized in that the die wall (2.2) in its area adjacent to the die bottom (2.1) has a plurality of projections

(4).

3. Device (1) according to claim 1 or 2, characterized in that the

Projections (4) have different widths (B) and / or different heights (H) and / or different depths (T) and / or different cross-sections, the height (H) of the projections (4) in each case a maximum of 95% of the die wall height ( HG) is.

4. Device (1) according to one of claims 1 to 3, characterized in that the projections (4) have a width (B) of 0.1 mm to 10 mm, preferably from 0.5 mm to 5 mm, particularly preferably from Have 1 mm to 2.5 mm.

5. Device (1) according to one of claims 1 to 4, characterized in that the projections (4) have a height (H) of 0.1 mm to 30 mm, preferably 0.5 mm to 10 mm, particularly preferably of Have 1 mm to 5 mm.

6. Device (1) according to one of claims 1 to 5, characterized in that the projections (4) a depth (T) of 0.01 mm to 1 mm, preferably from 0.05 mm to 0.5 mm, particularly preferably have from 0.1 mm to 0.25 mm.

7. The device (1) according to any one of claims 1 to 6, characterized in that the

Projections (4) have a cross section parallel to the die bottom, the cross section being a triangular, quadrangular, in particular trapezoidal,

Circular segment-shaped, in particular semicircular, shape.

8. The device (1) according to one of claims 1 to 7, characterized in that the projections (4) are arranged all around the entire circumference of the die wall (2.2).

9. Device (1) according to one of claims 1 to 8, characterized in that the

Die bottom (2.1) is circular, oval, rectangular, square, triangular or polygonal, the die wall (2.2) perpendicular to the

Die bottom (2.1) is arranged.

10. The method for producing a can packaging blank (10) by

Backward extrusion comprehensively the steps

a) providing a device (1) according to claims 1 to 9,

b) inserting a blank (6) with a thickness (HR) into the die (2),

c) inserting the press ram (3) and exerting a pressing pressure on the round blank (6),

d) removing the can packaging blank (10) from the die (2).

11. The method according to claim 10, characterized in that the in the

Die bottom (2.1) adjacent area of the die wall (2.2) provided projections (4) have a predetermined height (H), the height (H) being maximum

95% of the thickness (HR) of the blank (6) is, preferably at most 75%, particularly preferably at most 50% of the thickness (HR) of the blank (6).

12. The method according to any one of claims 10 or 11, characterized in that the projections (4) provided in the area of the die wall (2.2) adjacent to the die bottom (2.1) have a predetermined height (H), the predetermined height (H) is at least 5%, preferably at least 15%, particularly preferably at least 25% of the thickness (HR) of the blank (6).

13. Can packaging blank (10) with a longitudinal direction (LR) defining

Main axis (HA) and a wall (12) having an outside (12.1) and an inside (12.2), the wall (12) having a variable at least over a partial area (TB) of the can packaging blank (10) extending in the longitudinal direction (LR) Wall thickness (WD), characterized in that the partial area (TB) of the can packaging blank (10) with variable wall thickness (WD) starting from the bottom of the can packaging blank (10) over a maximum of 95% of the height in the longitudinal direction (LR) of the can packaging blank (10 ) and that the variable wall thickness (WD) is caused by the fact that only the outside (12.1) of the wall (12) is designed in relief.

14. Can packaging blank (10) according to claim 13, characterized in that the partial area (TB) of the can packaging blank (10) with variable wall thickness (WD) starting from the bottom of the can packaging blank (10) over a maximum of 75%, preferably over a maximum of 50% of the Longitudinal Height (LR) of

Can packaging blank (10) extends.

15. Can packaging blank (10) according to one of claims 13 or 14, characterized in that the portion (TB) of the can packaging blank (10) with a variable wall thickness (WD) starting from the bottom of the

Can packaging blank (10) over at least 5%, preferably at least 15%, particularly preferably at least 25% of the height in the longitudinal direction (LR) of the

Can packaging blank (10) extends.

16. Can packaging blank (10) according to any one of claims 13 to 15, characterized

characterized in that the relief-like design of the outside (12.1) of the wall (12) consists of groove-like depressions (11), these groove-like

Depressions (11) preferably run parallel to the main axis (HA).

17. Can packaging blank (10), producible using a device (1) according to one of claims 1 to 9.

18. Can packaging blank (10), producible by a method according to one of claims 10 to 12.

19. Can packaging (20), can be produced using a

Can packaging blank (10) according to one of claims 13 to 18.