Patent Application
20250206496
The invention relates to a package of sheet material with a tear-off foil cover, a kit of materials for producing such packages, a method for the production of the kit of materials and a method for the production of such filled packages according to the preambles of the independent patent claims.
Packages with tear-off foil covers (so-called Peel Off Ends or POE) are known from many different fields, in particular as food packages.
In the simplest case such packages consist of two parts, namely of a one-piece container and of a tear-off foil which seals a filling or extraction opening, respectively, of the container. These two-piece packages with tear-off foil covers have the disadvantage, however, that when the container is filled, contamination of the surfaces can occur which are provided for the seal connection with the tear-off foil, which can lead to a faulty sealing and thus to a leaky package. To have this risk as low as possible, the filled container must be moved relatively slowly until the tear-off foil is sealed, which limits the production speed significantly for such packages.
Basically, there is also a risk that the filling material is contaminated during sealing and/or altered by the impact of temperature.
In order to avoid the disadvantages of the two-piece packages described above, three- and four-piece packages with tear-off foil covers have been developed, in which the container is filled from the container end facing away from the tear-off foil cover, and in which this end is after that closed with a separate sheet metal cover.
These three- and four-part packages exhibit a frame formed by a rolled and longitudinally welded sheet metal ring, which forms the container walls and which is sealed at its first end with the tear-off foil cover and which is sealed at its second end with the aforementioned sheet metal cover. Depending on whether it is a three-part or a four-part package, the tear-off foil is sealed directly onto a sealing flange formed by the frame (three-part) or onto a separate sheet metal ring which is connected to the end of the frame (four-part).
Thereby, the disadvantage of the three-piece variants results that the sealing flange is crossed by a weld seam running radially through it, which is suboptimal from a process engineering point of view and can lead to leakage problems.
With the four-part variants, the disadvantage results that an additional component (sheet metal ring with sealing flange) has to be provided and processed, which leads to higher material and production costs and to additional waste during the manufacturing.
Also, in the case of the aforementioned three-part and four-part packages the disadvantage results that the sheet metal cover for the package bottom must be provided and managed separately, which leads to significantly higher material and production costs and additional waste during production compared to the two-part packages.
From WO 2021/176112 A1 a three-part package is known consisting of a deep-drawn cup which is closed with a two-part cover after filling, consisting of a sheet metal ring which central opening is covered by a sealing foil. With this package variant the disadvantage results that the handling of such two-part covers is problematic and that the production speed is limited accordingly.
Therefore, it is an objective to provide a package with a tear-off foil cover which does not have the abovementioned disadvantages of the prior art or at least partially avoids them.
This objective is solved by the objects of the independent patent claims.
According to these, a first aspect of the invention relates to a package made of sheet material with a tear-off foil cover. The package comprises a seamless frame made by deep drawing, which forms a package wall enclosing the interior space of the package. The frame has a first and a second end and forms at its first end an extraction opening surrounded by a sealing flange, which is closed by a tear-off foil cover glued or sealed onto the sealing flange. The second end of the frame is connected by flanging to a sheet metal cover which forms the bottom of the package.
The package according to the invention can, according to the methods of the invention also disclosed herein, be produced inexpensively from both sheet steel material and sheet aluminum material with low energy and material costs, has no weld seams such that there are virtually no problems with “blackening” and leaking, can be tested for tightness of the seal of the foil cover before filling, and enables high filling speeds because it can be filled from the bottom side.
The sealing flange advantageously extends radially outwards (in the direction away from the center of the removal opening) from the package wall formed by the frame such that it protrudes outwardly beyond the package wall in the plane of the tear-off foil cover. In this way, it is possible to provide an extraction opening which corresponds to the plane of the interior space of the package at the first end of the frame, such that in the case of a cylindrical interior space or an interior space which expands conically from the second to the first end of the frame, it is possible to remove a dimensionally stable filling material by inverting it. This is particularly advantageous in the case of groceries which are to be presented in a certain shape for consumption in a simple manner, such as canned tuna or meat pies.
It is also preferred that the sealing flange has a circumferential edge delimiting the sealing surface to the outside.
If the sealing flange and the package bottom are designed in such a way that the package bottom of a first package can be arranged inside the edge of an identical second package which delimits the sealing surface to the outside, this results in a good stackability with at the same time positive centering of the stacked packages on one another by the respective edge of the sealing flange.
With an advantage, the package wall formed by the frame defines an essentially cylindrical package interior space. This makes it possible to fill the frame with a dimensionally stable product from the second end and, in the case of packages with a sealing flange extending radially outwards, to remove this product later without loss of shape by inverting the opened package via the extraction opening at the first end of the frame.
If the package wall and the package bottom are made from an identical sheet material, in particular from an identical coated steel sheet material or aluminum sheet material, which is preferred, this has the advantage that only one type of sheet material needs to be managed for their manufacturing and particularly material-saving manufacturing processes become possible in which very little sheet material waste is produced.
If the package bottom is formed from a deep-drawn sheet material, it becomes possible to manufacture the frame and package bottom in an at least partially common manufacturing process.
A second aspect of the invention relates to a kit of materials for making of packages according to the first aspect of the invention.
The kit of materials comprises deep-drawn seamless frames for producing the package walls of the packages. The frames each form at a first end an extraction opening surrounded by a sealing flange which can be closed by glueing or sealing a tear-off foil cover onto the sealing flange, and at a second end a filling opening, via which the interior space enclosed by the package walls can be filled, in particular when the tear-off foil cover is glued or sealed onto the sealing flange.
The kit of materials further includes sheet metal covers with which the filling openings of the frames can be closed by producing a flanged connection between the respective frame and the respective sheet metal cover. The sheet metal cover then forms the bottom of the finished package.
If the sheet metal covers are made of a deep-drawn sheet metal material which is identical to the material of the frames, the advantage results that it becomes possible to manufacture the frame and sheet metal cover in an at least partially common manufacturing process. It is also foreseen, however, that the kit of materials according to the invention is made from separately manufactured frames and sheet metal covers or that it is formed from both commonly and separately manufactured frames and sheet metal covers.
In a preferred embodiment of the kit of materials, the extraction openings of the frames are each sealed with a tear-off foil cover glued or sealed onto the sealing flange, such that the interior space enclosed by the frame is closed at the first end of the frame and can be filled with a filling material.
Kits of materials according to the invention are preferred commercial forms of the invention.
A third aspect of the invention relates to a method for manufacturing of a kit of materials according to the second aspect of the invention. The method comprises the steps of:
Using the method according to the invention makes it possible to provide the frames and the cup bottoms in an at least partially common manufacturing process, whereby significantly less waste is produced and material costs can be saved compared to a separate supply of the cup bottoms.
With an advantage, the separation of the cup bottoms from the respective container together with a part of the cup wall is each made in such a way that the co-separated part of the cup wall forms a collar of uniform height around the cup bottom. This collar can then be re-shaped in a further processing step in such a way that it forms the flanging edge of the cover.
In a preferred embodiment, the method further comprises the step of sealing or glueing of tear-off foil covers onto the sealing flanges of the second container parts, respectively, in such a way that the cup opening is completely closed by the tear-off foil cover. By means of this, second container parts are provided in which the interior space enclosed by the frame is closed at the first end of the frame and can be filled with a filling material from the second end of the frame.
Thereby, it is further preferred that a leak test is each made of the second container part with the tear-off foil cover after it has been sealed or glued onto it. By means of this, leaky second container parts can be sorted out before filling and thus a high quality of the package can be guaranteed.
In yet another preferred embodiment, the method additionally comprises the step of re-shaping the collars of the first container parts or re-shaping the collars of the first container parts and the ends of the cup walls forming the filling opening of the second container parts, respectively, in such a way, that these regions can each be re-shaped in a further step into a flanged connection between one of the first container parts and one of the second container parts, for closing the filling opening of the second container part with the first container part. Therefore, in the kit of materials manufactured with this embodiment the frames and the sheet metal covers are already prepared for the production of the flanged connection between them.
Thereby, it is preferred that a putative re-shaping of the end of the cup wall of the second container part forming the filling opening each takes place before the tear-off foil cover is sealed or glued onto the sealing flange.
The respective sealing flange of the cup-like container is preferably formed in such a way that it extends radially outward from the cup opening (i.e. away from the center of the cup opening), such that it protrudes outwardly beyond the package wall in the plane of the tear-off foil cover. In this way, it is possible to provide an extraction opening which corresponds to the plane of the interior space of the package at the first end of the frame, such that in the case of a cylindrical interior space or an interior space which widens conically from the second end to the first end of the frame, a removal of a dimensionally stable filling material by inverting the opened package is possible. This is particularly advantageous in the case of groceries which are to be presented in a simple manner in a particular shape for consumption, such as canned tuna or meat pies.
Also, it is preferred that the sealing flange is designed in such a way that it has a circumferential edge limiting the sealing surface to the outside.
With an advantage, the cup-like container is manufactured in such a way that the package wall formed by the frame defines a substantially cylindrical package interior space. This makes it possible to provide kits of materials in which the frame can be filled from the second frame end with a dimensionally stable filling material and this filling material, in embodiments with a radially outward extending sealing flange, can be removed later without loss of shape by inverting the opened package via the extraction opening at the first end of the frame.
In another preferred embodiment of the method, the deep-drawn cup-like containers are each produced from a sheet material blank which is punched out at the manufacturing location of the cup-like container from an in particular coated sheet material web, in particular from a steel sheet material or from an aluminum sheet material.
In yet another preferred embodiment of the method, the tear-off foil covers are each punched out of a foil web at the manufacturing location of the cup-like container. This can be done outside of the sealing device or inside of the sealing device.
This results in the advantage that the kit of materials can be produced from semi-finished materials in a continuous process at one location without the need for intermediate storage and/or transport of intermediate products.
A fourth aspect of the invention relates to a method for manufacturing filled packages according to the first aspect of the invention. The method comprises the following steps:
Therefore, in this method, one or more kits of materials are produced according to the second aspect of the invention and these are processed into filled packages according to the first aspect of the invention by filling the second container parts and by closing the filling openings with the first container parts.
Thereby, it is preferred that the filling opening of the respective filled second container part is each closed with a first container part which has previously been separated from this second container part.
Alternatively thereto, it is preferred that the filling opening of the respective filled second container part is each closed with a first container part which has been separated from another one of the second container parts.
For the case that individual first container parts are lost or become unusable, it is also envisaged that these first container parts are replaced by separately manufactured sheet metal covers.
In a preferred embodiment of the method according to the fourth aspect of the invention, the re-shaping of the collar of the respective first container part which is used for closing the filling opening of the respective second container part takes place in the time period in which the putative re-shaping of the end of the cup wall of the second container part forming the filling opening, the sealing or glueing of the tear-off foil cover onto the sealing flange of the second container part and/or the filling of the second container part takes place. In this way, a continuous production can be achieved without expensive intermediate storage of the first container parts.
Any putative re-shaping of the end of the cup wall forming the filling opening of the respective second container part is advantageously carried out before the tear-off foil cover is sealed or glued onto the sealing flange. This considerably simplifies the handling of the second container part for the re-shaping step.
The sealing flange of the cup-like container is preferably formed in such a way that it extends radially outward from the cup opening (in the direction away from the center of the extraction opening), such that it protrudes outwardly beyond the package wall in the plane of the tear-off foil cover. In this way, it is possible to provide an extraction opening which corresponds to the plane of the interior space of the package at the first end of the frame, such that in the case of a cylindrical interior space or an interior space which widens conically from the second end to the first end of the frame, it is possible to remove a dimensionally stable filling material by inverting the opened package via the extraction opening. This is particularly advantageous in the case of groceries which are to be presented in a simple manner in a particular shape for consumption, such as canned tuna or meat pies.
It is also preferred that the sealing flange is designed in such a way that it has a circumferential edge that limits the sealing surface to the outside.
With an advantage, the sealing flange and the package bottom or the flanged connection between the first container part and the second container part, respectively, are each designed in such a way that the package bottom of a first package can be arranged inside the edge of the sealing flange of an identical second package which delimits the sealing surface to the outside.
This results in a good stackability of the produced packages with a simultaneous positive centering of the stacked packages on one another by the respective edge of the sealing flange.
The cup-like containers are preferably manufactured in such a way that they have a substantially cylindrical cup interior space. This makes it possible to fill the second container parts from the second frame end with a dimensionally stable filling material and, in embodiments with a sealing flange extending radially outwards, to remove this filling material later without loss of shape by inverting the opened package via the extraction opening.
In another preferred embodiment of the method, the deep-drawn cup-like containers are each produced from a sheet material blank which is punched out at the manufacturing location of the cup-like container from an in particular coated sheet material web, in particular from a steel sheet material or from an aluminum sheet material.
In yet another preferred embodiment of the method, the tear-off foil covers are each punched out of a foil web at the manufacturing location of the cup-like container.
This results in the advantage that the packages can be produced from semi-finished materials in a continuous process at one location without the need for intermediate storage and/or transport of intermediate products.
Before the filling of the second container parts, with an advantage a leak test on the respective second container part with the tear-off foil cover is performed. In this way, leaky second container parts can be sorted out before filling and thus a high quality of the filled packages can be guaranteed.
Further embodiments, advantages and applications of the invention are apparent from the dependent claims and from the now following description with reference to the figures. Thereby show:
The can comprises a seamless frame 1 of coated steel sheet material produced by deep drawing, which forms a can wall 6 enclosing the circular cylindrical interior space of the can.
At its upper end T (first end according to the claims), the frame 1 forms an extraction opening surrounded by a sealing flange 2 which is closed by a tear-off foil cover 3 sealed onto the sealing flange 2 and which is therefore not visible. The tear-off foil cover 3 comprises a tear-off tab 14 by means of which it can be pulled off the sealing surface of the sealing flange 2 in order to open the can.
At its bottom end B (second end according to the claims), the frame 1 is connected by a flange 12 to a sheet metal cover 4 which forms the can bottom 7. The sheet metal cover 4 is made of the same material as the frame 1.
As can be seen, the sealing flange 2 extends radially outward from the can wall 6 formed by the frame 1 such that it protrudes outwardly beyond the can wall 6 in the plane of the tear-off foil cover 3.
Thereby, the sealing flange 2 and the package bottom 7 are designed in such a way that the package bottom 7 of a first can be arranged within the edge 5 which delimits the sealing surface to the outside of an identical second can.
This results in a good stackability of the cans with an at the same time positive centering of the stacked cans on one another by the edge 5 of the sealing flange 2 of the respective lower can.
As can be seen, it is started from is a deep-drawn cup 9 (cup-like container according to the claims) made of coated steel sheet material, which has a cup opening, a closed cup bottom, a circumferential closed cup wall 6 extending between the cup bottom and the cup opening, and a sealing flange 2 surrounding the cup opening. The sealing surface of the sealing flange 2 of the cup 9 is delimited towards the outside by an upwardly projecting edge 5.
In a first processing step, the deep-drawn cup 9 is divided into a first cup part 10 (first container part according to the claims) and a second cup part 11 (second container part according to the claims) by separating the cup bottom with a part of the cup wall 6a. The first cup part 10 consists of the separated cup bottom with the co-separated part of the cup wall 6a, wherein the co-separated part of the cup wall 6a forms a collar of uniform height around the cup bottom. The second cup part 11 consists of the remaining cup wall 6b and the sealing flange 2 surrounding the cup opening.
In another step, the separated first and second cup parts 10, 11 are re-shaped into a frame 1 and a sheet metal cover 4 of the kit of materials 1, 4. For this, the collar 6a of the first cup part 10 and the end B of the cup wall 6b of the second cup part 11 which later forms the filling opening are re-shaped in such a way that these areas can be re-shaped in a further step into a flanged connection 12 between the sheet metal cover 4 formed from the first cup part 10 and the frame 1 formed from the second cup part 11, for a tight closure of the filling opening of the frame 1 with the sheet metal cover 4.
As can be seen, a frame 1 and a sheet metal cover 4 according to
After sealing of the tear-off foil cover 3, the frame 1 is turned over such that the tear-off foil cover 3 points downwards and that the filling opening formed by the bottom end B of the frame 1 points upwards. In this orientation, the tuna filling 13 in the form of a dimensionally stable pressed cake is introduced via the filling opening into the can interior space 8 enclosed by the can wall 6 of the frame 1. This has a cylindrical shape complementary to the shape of the press cake, such that the interior space 8 is virtually completely filled with the tuna filling.
Advantageously, a leak test of the frame 1 with the tear-off foil cover 3 is first carried out before the frame 1 is filled, but this is not shown here.
After the filling, the sheet metal cover 4 is placed on the bottom end B of the frame 1 and a flanged connection 12 is then made between the sheet metal cover 4 and the frame 1, thereby closing the frame 1 tightly at its bottom end.
After the closing of the filling opening with the sheet metal cover 4, the now finished tuna can is turned upside down such that the tear-off foil cover 3 faces upwards and such that the sheet metal cover 4 forms the can bottom 7.
While in the present application there are described preferred embodiments of the invention, it should be clearly noted that the invention is not limited to these and that it can be carried out in other ways within the scope of the following claims.
This application is a National Stage application of International Patent Application No. PCT/EP2022/055888, filed Mar. 8, 2022, the disclosure of which is incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/055888 | 3/8/2022 | WO |
