Container and method for producing a container

Abstract

The invention relates to a container (10) made of paper or paper-like material with a bottom (18), a shell (12), in particular a sleeve-like shell, and a lid (14), wherein the bottom (18) and the shell (12) are formed as separate parts made of paper or paper-like material and are connected to each other, and wherein the bottom (18) and the shell (12) are connected to each other in a liquid-tight and airtight manner by means of a circumferential first frame (20), wherein a bottom surface (28) of the bottom is at least partially convex outwards when viewed from the interior of the container (10), and a lower edge of the first frame (20), which connects the bottom (18) and the shell (12), forms a base for the bottom.

Description

[0001] The invention relates to a container made of paper or paper-like material with a bottom, a shell, in particular a sleeve-like shell, wherein the bottom and the shell are formed as separate parts made of paper or paper-like material and are connected to each other, and wherein the bottom and the shell are connected to each other in a liquid-tight and airtight manner by means of a circumferential first frame.

[0002] With multi-part containers, especially cans or tubes, made of paper or paper-like material, which are hermetically sealed when filled, the problem often arises that the container shrinks or collapses when filled and sealed. This occurs because the volume of the headspace gas—the gas in the space between the liquid level and the end of the container opposite the bottom, which is hermetically sealed—decreases. Such a reduction in headspace gas volume can be caused by cooling of the container or by chemical processes, such as a reaction of the headspace gas with the liquid inside. The container is airtight or gas-tight, so no pressure equalization through mass exchange is possible. A shrunken, deformed, or partially collapsed container is perceived by consumers as unattractive or damaged and is therefore not purchased. This shrinkage or collapse can be prevented by...Container collapse can be prevented by elaborate measures, such as cold filling and / or cooling the headspace gas before hermetically sealing the container. Generally, such containers can only be filled via the drinking or pouring hole, and filling is only possible while leaving a headspace. In other words, the container cannot be completely filled without headspace gas remaining in the space between the liquid level and the sealed top of the container. This is because the liquid being filled tends to foam or splash during filling. The headspace can be purged with cold nitrogen to keep the residual oxygen content low.This is also because residual oxygen affects the product and can cause it to oxidize, and also to prevent the headspace gas from cooling, which would lead to a reduction in volume and the creation of a vacuum in the container. Containers of the same size are sometimes filled with slightly different quantities, resulting in different headspace volumes. Known measures to prevent a filled and hermetically sealed container from collapsing or shrinking are comparatively complex.

[0003] The invention aims to improve a container made of paper or paper-like material and a method for manufacturing the container.

[0004] According to the invention, a container made of paper or paper-like material with the features of claim 1 or a method with the features of claim 10 is provided for this purpose. Advantageous further developments of the invention are mentioned in the dependent claims.

[0005] A container made of paper or paper-like material has a base and a shell, which is particularly tube-like. The base and the shell are formed as separate parts made of paper or paper-like material and are joined together. The base and the shell are each manufactured from separate, flat pieces of material. The base and the shell are connected to each other in a liquid-tight and airtight manner by means of a circumferential first frame. The container is sealed airtight and liquid-tight at its end opposite the base. At least part of the base surface, viewed from the interior of the container, is convexly curved outwards, and a lower edge of the first frame connecting the base and the shell forms a base for the container.

[0006] The base can be convex after being joined to the container, or it can be pre-shaped before being joined so that the base is already convex. The main advantage of a base that convexes outwards when viewed from the inside, i.e., a base that appears convex from the outside of the container, is that any negative pressure that arises inside the container after filling and sealing is compensated for solely by the deformation of the base. The container's outer shell does not contract, collapse, or deform. Only the outwardly convex base is drawn inwards, thus compensating for the negative pressure inside the container.In a surprisingly simple way, this prevents the container's outer shell from shrinking or collapsing after filling and closing, thus making the container unattractive to a buyer. Buyers primarily look at the container's outer shell and lid. Since, in the case of the container according to the invention, only the bottom may deform, and, for example, the curvature of the bottom may change only slightly, this goes unnoticed by the consumer, and the container is purchased. To create a liquid-tight and airtight seal between the lid and the outer shell, the lid can, for example, be connected to the shell with a second frame. However, according to the invention, the lid can also be connected to the shell in other ways to create a liquid-tight and airtight seal.Within the scope of the invention, the container can also be sealed airtight and liquid-tight at its end opposite the bottom in a manner other than with a lid, for example by placing a circuit board on top or by pressing together the upper end of the shell and subsequently gluing or sealing the material layers that then lie on top of each other.

[0007] The container according to the invention is made of paper, cardboard, or a paper-like material. Such containers are commonly referred to as cardboard containers. A paper-like material is defined as a material that can be processed similarly to paper or cardboard. Paper or cardboard contains fibers and, as a result, can practically not be stretched and can only be compressed to a very limited extent. In particular, paper, cardboard, or paper-like materials cannot be deep-drawn or, more generally, significantly deformed. Therefore, when manufacturing the container according to the invention from paper, cardboard, or a paper-like material, the body and base, and especially any lid or base plate, must be produced from separate, flat pieces of material and then joined together in a liquid-tight and airtight manner.Paper-like materials also include, for example, plastic materials that cannot be stretched or can only be stretched to a very limited extent. When manufacturing a container from paper, cardboard, or such paper-like materials, especially plastic materials, the body, base, and outer shell must all be made from flat pieces of material and joined together in an overlapping area in a liquid-tight and airtight manner, for example, by gluing.

[0008] The base and the body of the container are connected to each other in a liquid-tight manner by means of a first frame. The frame is formed, for example, by folding a lower edge of the body 180° around an edge of a base collar of the base, the base having a pot-like shape. The body and the base are then pressed together and sealed in the area of ​​the frame. For example, paper, cardboard, or paper-like material is used that is coated with a sealable material or that has a layer of sealable material. According to the invention, the lower edge of the base can also be folded around the lower edge of the body to form the frame.

[0009] For the manufacture of the casing and base, and especially for lids or circuit boards, paper, cardboard, or paper-like material coated on one side is generally used. For example, paper, cardboard, or paper-like material is used that is coated on at least one side with a sealable plastic layer. When manufacturing the casing, the lower edge of the casing and the base only need to be heated and pressed, resulting in a liquid-tight and airtight seal.

[0010] In principle, the invention also allows for the application of hot glue or adhesive to the areas of the material cutouts to be joined, including in the area of ​​the frames.

[0011] In a further development of the invention, the outwardly curved bottom surface is surrounded by a circumferential bottom collar, wherein the bottom collar is completely incorporated in the first frame that connects the shell and the bottom.

[0012] In this way, there is no dead space between the inside of the casing and the outside of the base collar in the finished, ready-to-fill container. This allows the interior of the container to be sterilized very effectively and completely before filling.

[0013] In a further development of the invention, the bottom collar is connected to the inside of the coat at least at its upper edge, where the bottom collar transitions into the bottom surface, in a material-bonded manner; in particular, the bottom collar is sealed to the inside of the coat at its upper edge.

[0014] This also prevents a gap or dead space from forming between the bottom collar and the inside of the coat, which is difficult to sterilize.

[0015] In a further development of the invention, as seen in a sectional view of the container, wherein the sectional plane contains a central longitudinal axis of the container, the lowest point of the outwardly curved bottom is arranged a maximum of one to two times the material thickness of the bottom, in particular 1 mm to 2 mm, above the base of the container.

[0016] The base is formed by the lower edge of the first frame. In cross-section, the bottom is convex to just before the lower edge of the first frame. The convex base does not impair the container's stability. The curvature of the base may change due to negative or positive pressure within the container, without affecting its appearance when displayed on a shelf.

[0017] In a further development of the invention, as seen in a sectional view of the container, wherein the section plane contains a central longitudinal axis of the container, the lowest point on the inside of the outwardly curved bottom is arranged 4 mm to 10 mm below the transition between the bottom surface and the bottom collar.

[0018] In this way, the base surface can be designed to be sufficiently flexible to compensate for the negative pressure that arises inside the container, yet the material of the base is not excessively deformed and there is no risk of the material of the base being damaged or its liquid tightness being impaired.

[0019] In a further development of the invention, in a sectional view of the container, wherein the section plane contains a central longitudinal axis of the container, the entire bottom surface is convex outwards.

[0020] In this way, sufficient space or mobility of the floor surface can be created to compensate for any negative pressure that may arise in the container, and the floor material is not subjected to excessive stress.

[0021] In a further development of the invention, the base has a ring-shaped indentation at the transition between the base collar and the base surface.

[0022] Before being joined to the shell, the base has a pot-like shape with a base collar and a base surface. If the base is pre-formed and the base surface is already convex before joining, the ring-shaped indentation is located at the transition between the base collar and the base surface, forming a hinge-like point. If a pot-shaped base blank is first created and then joined to the shell, the ring-shaped indentation lies within the base blank collar and forms a hinge-like point where the base blank collar bends as the base surface convexes. The section of the base blank collar located above the indentation, viewed from its lower edge, then forms part of the base surface in the fully formed base.On the finished container, the ring-shaped indentation is located at the transition between the bottom collar and the bottom surface, forming a hinge-like point.

[0023] In a further development of the invention, the base surface has several linear indentations converging radially towards the center of the base surface.

[0024] By means of such linear indentations converging radiating towards the center of the base surface, a defined deformation of the outwardly convex base can be achieved. Specifically, when a negative pressure is created within the airtight container, a controlled wrinkling of the base surface is achieved during deformation.

[0025] In a further development of the invention, the radially arranged linear indentations originate at least partially from the ring-shaped indentation.

[0026] On the finished container, the ring-shaped indentation is located at the transition between the base collar and the base surface, and the linear indentations then originate at least partially from the transition between the base collar and the base surface, so that a controlled folding of the entire base surface is possible.

[0027] In a further development of the invention, a lid made of paper or paper-like material is provided, wherein the lid and the jacket are connected to each other in a liquid-tight and airtight manner.

[0028] The headspace, filled with headspace gas after the container has been filled, lies between the liquid level and the underside of the lid.

[0029] In a further development of the invention, an end of the mantle opposite the ground is sealed in a liquid-tight and airtight manner.

[0030] A lid is not necessarily required to seal the container. Numerous methods exist for sealing the casing in a liquid-tight and airtight manner, but in all cases, the problem remains that a reduction in the volume of the headspace gas can occur, negatively affecting the container's external appearance through deformation.

[0031] In a further development of the invention, the end of the jacket opposite the ground is closed with a circuit board made of paper or paper-like material, plastic or metallic material, in particular aluminum.

[0032] As soon as the circuit board, which can also be designed as a stable film, for example, exhibits a certain compressive strength, a vacuum can develop in the filled container, which in turn can lead to deformation of the container's shell. The invention also provides a remedy here by allowing the bottom to be indented, thus preventing deformation of the shell or the circuit board.

[0033] In a further development of the invention, the jacket is compressed at the end opposite the ground in the form of at least two parallel layers of material, the layers of material being glued or sealed together, so that the jacket is sealed liquid-tight and airtight at the end opposite the ground.

[0034] Such a container is also called a tube. Although the shell of such a container is more stable due to its shape than a shell in the form of a cylindrical sleeve, a negative pressure inside the container can still deform the shell. The curved bottom according to the invention can prevent such deformation of the shell.

[0035] The problem underlying the invention is also solved by a method for manufacturing a container according to the invention, in which the curvature of a bottom surface of the base is provided from the interior of the container outwards.

[0036] Such a bottom surface, convex from the inside of the container, allows for the compensation of any negative pressure that may develop inside the airtight container by reducing the curvature of the bottom and / or creating controlled folds in the bottom surface. Since any negative pressure inside the container only deforms the bottom surface, the container's body and lid remain undamaged. This ensures the container remains visually appealing, as it is always displayed with the bottom facing downwards at points of sale. The convexity of the bottom surface, viewed from the inside of the container, can occur either after the bottom is joined to the body by the first frame, or the bottom can be pre-formed with the convex shape before being joined to the body.The warping of the base surface can be aided by heating the material of the container, so that in particular a plastic coating of the paper, cardboard or paper-like material becomes more easily deformable, and that after cooling the base surface of the bottom retains a warp.

[0037] In a further development of the invention, connecting the bottom to the shell by means of the first frame and suctioning the outside of the bottom surface after connecting the bottom to the shell to warp the bottom and / or pressurizing the inside of the bottom, which faces the interior of the container, to warp the bottom is provided.

[0038] The curvature of the base can be achieved by suction on the outer surface of the base and / or by pressurizing the interior of the base with gas pressure or by means of a piston. Suction on the base is preferred in the context of the invention so that the interior of the container is not contaminated or impaired.

[0039] In a further development of the invention, lateral support of an inner side of the frame between the shell and the base is provided when the base is curved.

[0040] In a further development of the invention, lateral support of the inside of the frame is provided over the entire height of the inside of the frame when the base is bowed.

[0041] By supporting the inside of the frame, particularly along its entire height when the base is being bent, damage to the seal is prevented. Specifically, this prevents the plastic layers on the inside of the container from tearing and exposing the backing material, usually paper. Supporting the frame along its entire inner height while the base is being bent allows the base to be pulled out precisely to the top edge of the seal. This eliminates dead spaces and prevents, for example, a gap around the perimeter, which are difficult or impossible to sterilize.

[0042] In a further development of the invention, the impressioning of a ring-shaped indentation into a flat, in particular circular, material blank for the base and the deformation of the material blank into a pot-shaped base blank with a circumferential base blank collar and a base blank surface is provided, wherein the ring-shaped indentation on the base blank is arranged within the base collar and there is a distance between the indentation and the transition between the base blank collar and the base blank surface.

[0043] In a further development of the invention, the distance between the indentation and the transition between the base blank collar and the base blank surface is between 1mm and 6mm, preferably between 2mm and 3mm.

[0044] In a further development of the invention, the connection of the base blank and the shell is provided by means of the first frame, so that the indentation is arranged at the upper end of the first frame.

[0045] In a further development of the invention, the sealing of the base blank collar to the inside of the coat is provided at least in a circumferential sealing area below the embossing, wherein the sealing area extends up to the embossing.

[0046] The sealing takes place during the production of the first frame, so that no liquid can penetrate the frame and there is no dead space or gap between the body and the bottom collar that cannot be sterilized and into which liquid could penetrate.

[0047] In a further development of the invention, the preforming of a, in particular circular, planar material blank into a pot-like base with a circumferential base collar and a base surface is provided, wherein, starting from a circumferential transition between the base collar and the base surface, the base surface is convex outwards, and the connection of the preformed base to the shell by means of the first frame is provided.

[0048] In a further development of the invention, the liquid-tight and airtight sealing of an end of the jacket opposite the ground by means of a lid made of paper or paper-like material, the liquid-tight and airtight sealing by means of a circuit board made of paper or paper-like material, plastic or metallic material, in particular aluminum, or the liquid-tight and airtight sealing of an end of the jacket opposite the ground by pressing the jacket together in the form of two parallel layers of material, wherein the layers of material are glued or sealed together, is provided.

[0049] Further features and advantages of the invention will become apparent from the claims and the following description of preferred embodiments of the invention in conjunction with the drawings. Individual features of the different embodiments can be combined with one another in any way without exceeding the scope of the invention. This also applies to the combination of individual features without further individual features with which they are presented and / or described. The drawings show: Fig. 1 shows a container according to the invention in a first embodiment in a view from an oblique top view, Fig. 2 shows a sectional view of a container according to the invention before the bottom is curved, Fig. 3 shows an enlarged detail of the sectional view of the Fig. 2 Fig. 4 shows a completed container according to the invention in a view from a low angle, Fig. 5 shows a sectional view of the container according to the invention during the curving of the bottom on a tool that is only partially shown, Fig. 6 shows an enlarged detail from Fig. 5 Fig. 7 a sectional view of the completed container according to the invention, Fig. 8 an enlarged detail from Fig. 7 Fig. 9 shows a flat strip of material with several circular material cutouts for producing a base for the container according to the invention, Fig. 10 shows a base blank for the container according to the invention, and Fig. 11 shows a sectional view of the base blank. Fig. 10 Fig. 12 shows a view of a preformed bottom for the container according to the invention, Fig. 13 shows a sectional view of the bottom of the Fig. 12 Fig. 14 shows a container according to the invention in a second embodiment from an oblique top view, Fig. 15 shows a sectional view of the container. Fig. 14 , Fig. 16 a container according to the invention in a third embodiment from an oblique angle above, Fig. 17 the container of the Fig. 16 from obliquely below and Fig. 18 the container of the Fig. 16 from the side.

[0050] The presentation of Fig. 1 Figure 1 shows a container 10 according to the invention made of paper, cardboard or paper-like material, which has a cylindrical shell 12 and a pot-shaped lid 14, which contains a Fig. 1 It features a concealed drinking opening that is sealed liquid-tight and airtight with a so-called Pull-Tab 16, and which has a Fig. 1 has unrecognizable soil 18.

[0051] The casing 12, the lid 14, and the base 18 are each made from a flat piece of material. The casing 12 is made from a rectangular piece of material that is rolled into a cylindrical sleeve and then placed in a Fig. 1 The overlap area is not visible and is glued together.

[0052] Base 18 is made from a circular piece of material and has a pot-like shape. Several flat pieces of material are used to make one base 18. Fig. 9 depicted.

[0053] The lid 14 is also made from a circular piece of material and also has a pot-like shape.

[0054] The outer shell 12 and the base 18 are connected to each other by means of a first frame 20, the structure of which is in Fig. 6 This is clearly visible. A lower edge of the cylindrical shell 12 is folded around a lower edge of a base collar of the base 18, and the base collar is then held between the folded section of the shell 12 and the lower end of the unfolded area. The three material layers, which are then stacked on top of each other, are pressed together and heated simultaneously. A sealable coating or layer is provided between the individual material layers, so that when the frame is formed, the base collar and the shell bond together in a liquid-tight and airtight manner.

[0055] Similarly, a second frame 22 is formed, which connects the lid 14 and the casing 12 in a liquid-tight and airtight manner. After the container 10 has been filled, the pull tab 16 is applied to the drinking hole or areas adjacent to the drinking hole on the upper surface of the lid 14 and bonded to the upper surface of the lid, in particular by sealing.

[0056] The container 10 is sealed liquid-tight and airtight after filling and attaching the pull tab 16.

[0057] The container 10 cannot be filled completely, but only to just below the underside of the lid 14. This is because the liquid being filled foams and / or splashes, inevitably allowing gas to enter the interior of the container 10. Furthermore, the top of the lid 14 must be free of liquid before the pull tab 16 is attached, otherwise the pull tab 16 cannot be sealed to the top of the lid 14 in a liquid-tight and gas-tight manner.

[0058] After filling container 10 and sealing it in a liquid-tight and airtight manner, a headspace exists above the liquid level of the liquid in container 10 and the underside of the lid 14. This headspace is filled with a headspace gas. This headspace gas can be air or, in the case of liquids that can react with the residual oxygen in the headspace gas, for example, nitrogen if the headspace is purged with nitrogen after filling the container. A vacuum can now develop within the headspace after filling and sealing container 10. This can occur due to the cooling of the headspace gas or through a chemical reaction of the headspace gas with the liquid in container 10.

[0059] To prevent the shell 12 or the lid 14 of the container 10 from shrinking or collapsing, the bottom 18 is, according to the invention, convex outwards from the interior of the container 10. This outwardly convex bottom 18 can deform when a vacuum is created in the interior of the container 10 and, for example, deform towards the interior of the container. This allows the container 10 to retain its shape even when a vacuum is created. Fig. 1 The visible, flawless cylindrical shape of the casing 12 with a flat lid 14 is ensured. This prevents the container 10 from appearing unattractive and not being purchased. When sold, the container 10 is generally in the Fig. 1 The product is positioned as shown, in which base 18 is not visible. A potential buyer therefore cannot see base 18 and consequently cannot perceive that base 18 may have changed shape between being filled and being purchased.

[0060] Fig. 7 Figure 1 shows a cross-sectional view of the completed container before filling. One section plane contains a central longitudinal axis of the container 10. It can be seen that the lid 14 and the body 12 are connected to each other by means of the second frame 22, and that the body 12 and the base 18 are connected to each other by means of a first frame 20. A drinking opening 24 in the lid 14 is shown in the state of Fig. 7 not yet via a pull tab, see Fig. 1 , locked.

[0061] It is in Fig. 7 and in the enlarged view of a detail from Fig. 7 in Fig. 8 It can be seen that the base 18 has a base collar 26 and a base surface 28. The base collar 26 is located between the inside of the casing 12 and a folded-over section 30 of the casing 12. The folded-over section 30, the base collar 26, and the section of the casing 12 located at the lower edge of the casing 12 opposite the folded-over section 30 are pressed together, bonded together by means of a material connection, for example by means of seals, and form the first frame 20. The first frame 20 connects the casing 12 and the base 18 in a liquid-tight and airtight manner.

[0062] The base surface 28 is convex outwards when viewed from the interior of the container 10. The entire base surface 28 is convex outwards; that is, starting from the transition between the base collar 26 and the base surface 28, the base surface 28 is continuously convex. The base surface 28 therefore has the shape of a section of a spherical surface or an inverted cap shape.

[0063] It can be seen that the first frame 20 extends to the upper end of the base collar 26. Above the first frame 20, the base is already bent, and the base collar 26 transitions into the base surface 28. As a result, no circumferential gap is created between the base collar 26 and the inside of the casing 12, and therefore no dead space exists that cannot be sterilized, or cannot be completely sterilized, before filling.

[0064] The bottom 18, which curves outwards from the interior of the container 10, compensates for any negative pressure that arises inside the container 10 when it is filled and hermetically sealed. To compensate for this negative pressure, the curved bottom surface 28 moves upwards in sections or folds in a controlled manner. This is not perceptible to a potential buyer, and in particular, the controlled deformation of the bottom surface 28 ensures that the outer casing 12 and the lid 14, which are visible to a potential buyer, for example on a retail shelf, do not deform.

[0065] Fig. 9 Figure 1 shows a strip of material 32 made of plastic-coated paper or cardboard. The strip of material 32 can also be made of a paper-like plastic material, for example. Circular material blanks 34 are punched out of the flat strip of material 32, each of which is used to manufacture a base 18. According to the invention, the circular material blanks 34 can be provided with an embossing consisting of a circular groove or embossing 36 and several linear embossings 38 radiating towards the center of the material blank 34. The linear embossings 38 extend from the annular embossing 36 and terminate before the center of the material blank 34. The linear embossings 38 are spaced apart from one another; in particular, the linear embossings 38 do not intersect or touch each other.

[0066] Within the scope of the invention, the annular indentation 36 and / or the linear indentations 38 can also be omitted. The annular indentation 36 is intended to form a hinge-like structure when the base is convex. The linear indentations 38 are intended to enable controlled wrinkling when the base surface 28 deforms due to the creation of a vacuum inside the container 10.

[0067] The Fig. 12 und 13 Figure 1 shows a completed base 18. The base 18 can be pre-formed before being inserted into the shell 12, i.e., before being connected to the shell 12, so that it is in the state of Fig. 12 und 13 is connected to coat 12.

[0068] Alternatively, the material blank 34 can first be formed into a base blank 40, as shown in Fig. 10 und Fig. 11 This base blank 40 can then be connected to the jacket 12 in a liquid-tight manner, see [reference]. Fig. 2 and Fig. 3 , and only after being connected to the shell 12 is the bottom surface 28 of the bottom 18 convex from the inside of the container 10, see Fig. 5 und Fig. 6 .

[0069] The base blank 40 has a pot-like shape with a base blank collar 42 and a base blank surface 44. The base blank collar 42 has a circumferential groove that extends from the outside of the base blank collar 42 inwards and is defined by the ring-shaped indentation 36, cf. Fig. 9 , is educated.

[0070] Above the ring-shaped indentation 36, the base blank collar 42 extends further by a section 46 before transitioning into the base blank surface 44 at a circumferential bend 48. The base blank surface 44 is flat, see the sectional view of the Fig. 11 , and has several linear indentations 38, which radiate inwards and each form a shallow groove, which in the view of the Fig. 10 extends downwards. In area 46 and in the transition area 48, the indentations 38 are no longer shown, since the indentations are completely pressed out of the material blank again when the base blank collar 42 is bent.

[0071] The sectional view of the Fig. 11 The circumferential groove or indentation 36 in the base blank collar 42 and also the area 46 of the base blank collar 42, which continues the base blank collar above the indentation 36, are visible. The transition area 48 forms a right-angled bend and thus the transition from the base blank collar 42 to the flat base blank surface 44.

[0072] According to a preferred embodiment of the invention, the base blank 40, see Fig. 2 and Fig. 3 , liquid-tight and airtight connected to the casing 12 by means of the first frame 20. It is Fig. 2 and Fig. 3 It can be seen that the circumferential indentation 36 lies precisely above the first frame 20. In other words, the lower edge of the casing 12 is folded over, or the base collar is inserted into the fold of the casing 12, until the indentation 36 rests against the upper edge of the folded section of the casing 12. In this state, the frame 20 is formed, and the section of the base collar 42 located within the fold is bonded to the casing 12, for example, by means of seals, so that the frame 20 then connects the base blank 40 and the casing 12 in a liquid-tight and airtight manner.

[0073] It is Fig. 2 and Fig. 3 It can be seen that the area 46, which continues the base blank collar 42 above the indentation 36, is located above the frame 20. The area of ​​the indentation 36 and the area 46 are therefore not bonded to the inside of the casing 12. Consequently, the area 46 can be bent around the indentation 36, which forms a hinge-like area, so that ultimately the Fig. 7 und Fig. 8 The depicted curved shape of the floor surface 28 results.

[0074] To the container of Fig. 2 and the Fig. 3 To complete the process, the bottom surface 28, which curves outwards from the interior of the container 10, must be produced. For this purpose, the container 10 is in the state of Fig. 2 and Fig. 3 mounted on a tool 50, see Fig. 5 , which has a stop for the lower edge of the first frame 20, which forms the base of the container 10, and which laterally supports the inside of the frame 20. This is achieved by means of a circumferential ring surface 52 of the tool 50, the ring surface 52 bearing against the inside of the frame 20. The ring surface 52 fully supports the inside of the frame.

[0075] The tool 50 further has an inwardly curved contact surface 54, against which the base blank surface is placed to form the base surface 28.

[0076] For this purpose, the outer underside of the base blank surface is drawn in via vacuum channels 56 in the tool 50 until the outer surface of the base blank rests against the contact surface 54, thereby creating the convex base surface 28. When the vacuum in the suction channels 56 is switched off, the base surface 28 moves away from the contact surface 54 again. This state is in Fig. 5 und Fig. 6 The diagram shows that area 46, as well as the bend 48 of the base blank 40, now form part of the base surface 28. A bend between the base collar 26 and the base surface 28 lies in the area where the indentation 36 was present on the base blank 40. Area 46 now forms the outer edge of the base surface 28, and area 48, which on the base blank 40 formed the bend between the base blank collar 42 and the base blank surface 44, now also forms part of the base surface 28.

[0077] In the presentation of the Fig. 6 The positioning of the indentation 36, the area 46, and the transition 48 is indicated by dashed arrows. Due to the deformation of the base blank 40 in these areas, they are no longer visible in the finished state of the container 10. It can be observed that the indentation 36, the area 46, and the transition 48 are only deformed to such an extent that a plastic coating of the base blank 40 is not damaged, and the finished base surface and the finished container 10 are therefore liquid-tight and airtight.

[0078] Fig. 14 Figure 1 shows a container 50 according to a second embodiment of the invention. The container 50 has a sleeve-shaped shell 52 and a domed bottom, which is Fig. 14 The casing is not visible. At its end opposite the base, the casing is provided with a flattened mouth roll 54. A flat sheet 56 made of paper or paper-like material is placed on this flattened mouth roll and connected to the top of the flattened mouth roll 54 in a liquid-tight and airtight manner, for example by sealing. The sheet 56 can be made of paper or paper-like material, plastic, or even metallic material, such as aluminum, and if it is made of plastic or metallic material, it can be designed as a stable foil.

[0079] Fig. 15 Figure 1 shows a cross-sectional view of container 50. Visible is the bottom 58, which curves outwards from the interior of container 50 and is connected to the shell 52 in the same way as the bottom of container 10, namely by means of a frame; see also Figure 2. Fig. 8 In Fig. 15 The flattened mouth roll 54 can be seen in the cross-section. To produce the flattened mouth roll 54, the upper edge of the sheath 52 is first rolled outwards over its entire circumference. This rolling is carried out for an angle of approximately 180°. Subsequently, this mouth roll is then flattened so that the in Fig. 15 The depicted shape of the flattened mouth roll 54 is created. The flattened mouth roll 54 has a flat, ring-shaped upper surface. The circuit board 56 is placed on this upper surface of the flattened mouth roll 54. As also in Fig. 14 As can be seen, the circuit board 56 has a generally circular shape with a tear-off tab 60, the tear-off tab 60 extending outwards from the circular shape. The circuit board 56 can be grasped at the tear-off tab 60 and pulled off the top of the flattened mouth roll 54 in order to open the container 50.

[0080] The circuit board 60 is advantageously provided with a sealable layer on its underside, which rests on the flattened mouth roll. Similarly, the top side of the flattened mouth roll 54 is provided with a sealable layer. To seal the interior of the container 50 in a liquid-tight and airtight manner, the circuit board 56 is placed on the top side of the flattened mouth roll 54 and then sealed. This creates a liquid-tight and airtight connection between the underside of the circuit board 56 and the top side of the flattened mouth roll 54.

[0081] The interior of container 50 is then sealed liquid-tight and airtight. If a headspace gas contracts in a headspace between a liquid level in container 50 and the underside of the circuit board 56, a negative pressure can develop in the interior of container 50. Deformation of the shell 52 and / or the circuit board 56 is then prevented in the manner already described by the fact that the curved base 58 is drawn upwards at least a short distance, i.e., towards the circuit board 56.

[0082] Fig. 16 Figure 1 shows a container 70 according to a third embodiment of the invention. The container 70 has a shell 72 and a [missing information - likely a specific feature or element]. Fig. 16 The bottom is not visible. The bottom is formed and connected to the shell 52 in the same way as in the container 10 of the Fig. 1 bis 8 The jacket 72 has a circular cylindrical shape before the upper end opposite the base is closed. To close the container 70, an upper end of the jacket 72 opposite the base is compressed so that a sealing strip 74 is formed, consisting of at least two parallel and abutting layers of material from the jacket 72. In the area where an overlap 76 is located, three layers of material are consequently located on top of each other in the area of ​​the sealing strip 74. This area of ​​the sealing strip 74 is in Fig. 16 marked with the reference number 78. In the area of ​​the sealing strip 74, the adjoining layers of material are glued or sealed together. This ensures that the container 70 is sealed liquid-tight and airtight at its end opposite the base. The domed base then prevents deformation of the outer surface of the container 70, in particular the shell 72, which is visible to a consumer, should a vacuum develop inside the container 70.

[0083] Fig. 17 shows another view of container 70 of the Fig. 16 . In this view it can be clearly seen that the upper end of the coat 72 was pressed together to form the closure strip 74.

[0084] Fig. 18 shows another view of container 70 of the Fig. 16, where the sealing strip 74 is shown from the side. In the area of ​​the sealing strip 74, the jacket 72 has been compressed and the layers of material lying on top of each other in the area of ​​the sealing strip 74 have been joined together in a liquid-tight and airtight manner.

Claims

1. Container made of paper or paper-like material with a bottom and a shell, in particular a sleeve-like shell, wherein the bottom and the shell are formed as separate parts made of paper or paper-like material and are joined together and wherein the bottom and the shell are connected together in a liquid-tight and airtight manner by means of a circumferential first frame, characterized by the fact that a bottom surface of the base, viewed from the interior of the container, is at least partially convex outwards, and a lower edge of the first frame connecting the base and the shell forms a standing surface for the container.

2. Container according to claim 1, characterized by the fact thatthe bottom surface, which is at least partially convex outwards, is surrounded by a circumferential bottom collar, wherein the bottom collar is completely incorporated into the first frame connecting the shell and the bottom, wherein in particular the bottom collar is connected to the inside of the shell at least at its upper edge, where the bottom collar transitions into the bottom surface, in a material-bonded manner, in particular sealed to the inside of the shell.

3. Container according to at least one of the preceding claims, characterized by the fact thatseen in a sectional view of the container, wherein the section plane contains a central longitudinal axis of the container, the lowest point of the outwardly convex bottom is located at most one to two times the material thickness of the bottom, in particular 1 mm to 2 mm, above the base of the container and / or that seen in a sectional view of the container, wherein the section plane contains a central longitudinal axis of the container, the lowest point on the inside of the outwardly convex bottom is located 4 mm to 10 mm below the transition between the bottom surface and the bottom collar.

4. Container according to at least one of the preceding claims, characterized by the fact that seen in a cross-sectional view of the container, where the section plane contains a central longitudinal axis of the container, the entire bottom surface is convex outwards.

5. Container according to at least one of the preceding claims, characterized by the fact thatthe floor has a ring-shaped indentation at the transition between the floor collar and the floor surface and / or the floor surface has several linear indentations converging radiating towards the center of the floor surface, in particular the radially arranged linear indentations originating at least partially from the ring-shaped indentation.

6. Container according to at least one of the preceding claims, characterized by the fact that a lid made of paper or paper-like material is provided and that the lid and the jacket are connected to each other in a liquid-tight and airtight manner.

7. Container according to at least one of the preceding claims 1 to 5, characterized by the fact that one end of the mantle opposite the ground is sealed to be liquid-tight and airtight.

8. Container according to claim 7, characterized by the fact thatthe end of the jacket opposite the ground is sealed liquid-tight and airtight with a circuit board made of paper or paper-like material, plastic or metallic material, in particular aluminium.

9. Container according to claim 7, characterized by the fact that The mantle is compressed at the end opposite the ground in the form of two parallel layers of material, the layers of material being glued or sealed together, so that the mantle is sealed liquid-tight and airtight at the end opposite the ground.

10. Method for manufacturing a container according to at least one of the preceding claims, characterized by Bending of a floor surface of the ground, viewed from the inside of the container towards the outside.

11. Method according to claim 10, characterized byConnecting the bottom to the shell by means of the first frame and suctioning the outside of the bottom surface after connection to warp the bottom and / or pressurizing the inside of the bottom, which faces the interior of the container, to warp the bottom, in particular characterized by Lateral support of an inner side of the frame between the rim and the base during the warping of the base, in particular, characterized by Lateral support of the inside of the frame over the entire height of the inside of the frame when the base warps.

12. Method according to claim 10 or 11, characterized byImprinting a ring-shaped indentation into a flat, in particular circular, material blank for the base and deforming the material blank into a pot-shaped base blank with a circumferential base blank collar and a base blank surface, wherein the ring-shaped indentation on the base blank is arranged within the base blank collar and there is a distance between the indentation and the transition between the base blank collar and the base blank surface, wherein in particular the distance between the indentation and the transition between the base blank collar and the base blank surface is between 1mm and 6mm, preferably between 2mm and 3mm.

13. Method according to claim 12, characterized by Connecting the base blank and the shell by means of the first frame, so that the indentation is located at the upper end of the first frame, in particular characterized bySealing the base collar to the inside of the coat at least in a circumferential sealing area below the impression, the sealing area extending to the impression.

14. Method according to at least one of claims 10 to 13, characterized by Pre-forming a, in particular circular, flat material blank into a pot-like base with a circumferential base collar and a base surface, wherein, starting from a circumferential transition between the base collar and the base surface, the base surface is convex outwards, and connecting the pre-formed base to the shell by means of the first frame.

15. Method according to at least one of claims 10 to 14, characterized byliquid-tight and airtight sealing of an end of the jacket opposite the ground by means of a cover made of paper or paper-like material, by liquid-tight and airtight sealing of an end of the jacket opposite the ground by means of a plate made of paper or paper-like material, plastic or metallic material, in particular aluminium, or by liquid-tight and airtight sealing of an end of the jacket opposite the ground by compressing the jacket in the form of two parallel layers of material, wherein the layers of material are glued or sealed together.

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