Packaging Container And A Method Of Producing Such A Packaging Container

A paperboard packaging container for bulk solids and a method of forming a paperboard packaging container for bulk solids. The container having a container body closed at one end by a lid formed by sequential insertion and attachment of a first paperboard insert and a second paperboard insert.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of Swedish Patent Application No. 2250951-7, filed on Aug. 5, 2022.

INCORPORATION BY REFERENCE

The disclosure of Swedish Patent Application No. 2250951-7, filed on Aug. 5, 2022, is hereby incorporated by reference for all purposes as if presented herein in its entirety.

TECHNICAL FIELD

The present disclosure pertains to a method of producing a paperboard packaging container for bulk solids and a paperboard container for bulk solids.

BACKGROUND OF THE DISCLOSURE

In the area of disposable containers for products such as infant formula, tobacco, detergents, etc. there is an ongoing need of diminishing the carbon footprint of such products, by minimizing the resource use for the disposable containers as well as making the containers recyclable. The disposable containers referred to herein are composite containers having a tubular body which is made from a laminate sheet material comprising a carton layer, i.e., a layer made predominantly from cellulosic fibers. The upper and lower end edge of the container may include a plastic rim connected to the edges of the packaging container. This provides the packaging containers with a pleasant and neat appearance and the container top or bottom may also be more wear resistant. The bottom of the container may alternatively be made from a folded-in end portion of the tubular body or may be a bottom insert/disc which is attached to the tubular body at the bottom end. The appearance may however for such packaging containers be somewhat less attractive and less wear resistant at the bottom end of the packaging container.

Accordingly, an object of the present disclosure is to provide an improved packaging container offering better stability and easier opening of the lid of the container. Another object is to provide a method of manufacturing such a container.

SUMMARY OF THE DISCLOSURE

In one aspect, the disclosure is generally directed to a method of forming a paperboard packaging container for bulk solids. The method comprises obtaining a body blank having a first side edge and a second side edge, the body blank being made of a laminate sheet material comprising a carton substrate layer. The method comprises forming a container body from the body blank, the container body defines an inner compartment, the container body comprises a container body wall having an inner surface facing the inner compartment, an outer surface facing away from the inner compartment, and a weakened portion extending along at least a portion of the circumference of the container body, the container body comprises a first end with a first end opening and a second end opposite the first end having a second end opening. The method comprises closing the first end opening by pressing a first paperboard insert into the first end opening to a first predetermined position relative to the container body and forming an external recess, the first paperboard insert comprising a first central portion covering the first end opening and a first peripheral flange portion, at the first predetermined position of the first paperboard insert. The method comprises attaching the first peripheral flange portion of the first paperboard insert to the container body wall at a first attachment portion of the container body, the weakened portion in the container body wall is between the first attachment portion and the second end of the container body. The method comprises pressing a second paperboard insert into the external recess through the first end opening to a second predetermined position relative to the container body, the second paperboard insert comprising a second central portion covering the first end opening and a second peripheral flange portion. The method comprises attaching the second peripheral flange portion of the second paperboard insert to the container body wall.

According to another aspect, the disclosure is directed to a paperboard packaging container for bulk solids. The container comprises a container body defining an inner compartment. The container body comprises a container body wall made of a laminate sheet material comprising a carton substrate layer. The container body comprises a first end with a first end opening and a second end opposite the first end having a second end opening. The container body wall has an inner surface facing the inner compartment and an outer surface facing away from the inner compartment. A first paperboard insert closes the first end opening, the first paperboard insert comprising a first central portion covering the first end opening and a first peripheral flange portion. The first paperboard insert is located in the container body and forms an external recess. The first peripheral flange portion is attached to the inner surface of the container body wall at a first attachment portion of the container body. The container body being has a weakened portion extending along at least a portion of the circumference of the container body. The weakened portion is between the first attachment portion and the second end of the container body. The packaging container further comprises a second paperboard insert positioned in the external recess and covering the first end opening. The second paperboard insert comprises a second central portion and a second peripheral flange portion attached to the container body wall.

According to one aspect, the object above is achieved by a method of forming a paperboard packaging container according to the subject matter of the claims, in the following description and in the drawings. In one embodiment, the method is a method of forming a paperboard packaging container from a body blank. The method comprises a step a) of obtaining a body blank having a first side edge and a second side edge, said body blank being made of a laminate sheet material comprising a carton substrate layer.

Also, the method comprises a step b) of forming a tubular container body from the body blank.

Further, the method comprises a step c) of sealing together the first side edge and the second side edge, wherein the tubular container body defines an inner compartment, wherein the container body comprises a container body wall having an inner surface facing the inner compartment and an outer surface facing away from the inner compartment, and wherein the container body comprises a first end with a first end opening and an opposite second end with a second end opening.

Also, the method comprises a step d) of closing the first end opening by pressing a first paperboard insert into the first end opening to a first predetermined position relative to the container body, the first paperboard insert comprising a first central portion covering the first end opening, and comprising a first peripheral flange portion directed away from the first central portion towards the first end opening of the container such that an external recess of the packaging container is formed,

Further, the method comprises a step e) of attaching the first peripheral flange portion of the first paperboard insert to the container body wall.

Also, the method comprises a step f) of pressing a second paperboard insert into the external recess through the first end opening to a second predetermined position relative to the container body, the second paperboard insert comprising a second central portion covering the first end opening, and comprising a second peripheral flange portion directed away from the second central portion towards the first end opening of the container body.

Further, the method comprises a step g) of attaching the second peripheral flange portion of the second paperboard insert to the container body wall.

By attaching a first and second paperboard insert to the container body wall, a double-wall lid structure is formed by the first paperboard insert and the second paperboard insert. The lid structure is more robust than a single-wall lid structure formed when using only one paperboard insert and thus enables stability of the lid also for packaging containers with larger cross-sectional area and produced with weaker material. Increased stability of the lid also enables easier handling of the lid at separation of the lid from the rest of the packaging container with reduced risk of breaking/deforming the lid.

The method may further comprise a step h) of deforming the second central portion of the second paperboard insert prior to attaching the second peripheral flange portion to the container body wall, such that a recessed portion of the second paperboard insert is formed adjacent the second peripheral flange, said recessed portion being shaped such that a distance between the second central portion of the second paperboard insert and the first central portion of the first paperboard insert is reduced at the recessed portion.

By deforming the second central portion prior to attaching the second peripheral flange portion to the container body wall, the material of the paperboard insert is free to move during deformation, such that material of the paperboard blank used to form the paperboard insert is able to move from the peripheral portion of a second paperboard blank used for forming of the second paperboard insert, thereby mitigating stretching of the paperboard material during deformation of the second central portion of the second paperboard insert.

Step f) may be performed by forcing the second paperboard insert into the external recess using a footprint surface of a press tool, said footprint surface having a shape and size adapted to the shape and size of the first end opening of the container body, and having a protrusion for forming the recessed portion of the second paperboard insert.

Step f) may comprises positioning a guide plate adjacent the first end opening of the container body such that a through cavity of the guide plate is aligned with the first end opening, said through cavity having a shape and size corresponding to the shape and size of the first end opening of the container body, wherein the second paperboard insert is guided into the external recess through the through cavity of the guide plate at pressing of the second paperboard insert into the external recess, wherein the second peripheral flange portion is bent between the guide plate and the press tool.

The use of such a guide plate, protects the first end of the container body such that deformation of the paperboard blank occurs mainly as a result of forces acting on the paperboard blank by the guide plate and the press tool, rather than between the container body wall and the press tool.

The through cavity of the guide plate may have a recessed portion extending the through cavity laterally with respect to an insertion direction along which the second paperboard insert is inserted into the external recess, said recessed portion of the through cavity being positioned adjacent where the protrusion of the footprint surface passes through said through cavity.

The recesses portion reduces the area/edge length of the through cavity of the guide plate on which the blank slides at deformation between the press tool and the guide plate, thus enabling increased local stress on portions of the paperboard blank such that the paperboard blank folds at intended locations as the second peripheral flange portion is folded to point away from the second central portion of the second paperboard insert.

According to a second aspect, the object above is also achieved by a paperboard packaging container according to the claims, in the following description and in the drawings. The packaging container is suitable for bulk solids and the container comprises a tubular container body defining an inner compartment. The container body comprises a container body wall made of a laminate sheet material comprising a carton substrate layer, and comprises a first end with a first end opening and an opposite second end with a second end opening. The container body wall has an inner surface facing the inner compartment in the packaging container and an outer surface facing away from the inner compartment. The first end opening is closed by a first paperboard insert comprising a first central portion covering the first end opening. The first paperboard insert further comprises a first peripheral flange portion directed away from the first central portion towards the first end opening of the packaging container such that an external recess of the packaging container is formed. The first peripheral flange portion is attached to the inner surface of the container body wall at a first attachment portion of the container body. Also, the container body has a weakened portion extending along at least a portion of the circumference of the container body, the weakened portion is between the first attachment portion and the second end of the container body. The packaging container further comprises a second paperboard insert positioned in the external recess and covering the first end opening. The second paperboard insert comprises a second central portion and a second peripheral flange portion directed away from the second central portion towards the first end opening of the packaging container. The second peripheral flange portion is attached to the inner surface of the container body wall or can alternatively be attached to the first peripheral flange of the first paperboard insert.

The first paperboard insert and the second paperboard insert both attach to the container body wall. At opening of the packaging container, a user grabs the first end of the container body, typically by grabbing the second peripheral flange portion of the second paperboard insert, and pulling such that the container body wall separates at the weakened portion. Since the weakened portion is between the first attachment portion and the second end of the container body, the first paperboard insert and the second paperboard insert together form a lid comprising the torn off portion or upper portion of the container body wall. The combination of the two paperboard inserts improves rigidity of the lid and makes the lid easier to handle during and after separation of the lid from the rest of the container body.

The second central portion of the second paperboard insert may comprise a recessed portion adjacent the container body wall.

The recess adjacent the container body wall makes it easier for the user to grab hold of the lid when tearing it off the rest of the container body by increasing the surface area available to be gripped by the user. The recess also provides a visual indication for the user where to grab, thus making it even easier to remove the lid, since pulling the lid off the rest of the container will be more difficult if pulled at an arbitrary location.

The second paperboard insert may be formed from a paperboard blank, wherein said paperboard blank comprises a central portion having a shape and size corresponding to the shape and size of the first end opening of the container body, and a peripheral portion surrounding the central portion.

As shown inFIG.3, the peripheral portion of the paperboard blank may be enlarged adjacent a portion of the paperboard blank where the recessed portion is formed.

By enlarging the paperboard blank adjacent where the recessed portion is formed, extra material is available to form the recessed portion without reducing the amount of material available for forming the second peripheral flange portion. This enables attachment of the second peripheral flange portion to the container using welding or adhesive bond extending around the circumference of the first end opening of the packaging container in a planar fashion.

The second central portion of the second paperboard insert may comprise a grip opening which may be covered by a removable cover.

The grip opening provides an alternative to the recess discussed above. The grip opening enables a user to grab the lid through the grip opening, thus reaching a larger surface area of the lid to grab hold of. The grip opening may be covered by a separate lid member or membrane, or may be covered by a portion made from the same paperboard blank as the second paperboard insert by provision of a scoring, perforation or similar extending at least partly around the circumference of the grip opening such that the user gains access to the opening by forcing the cover into the space between the first paperboard insert and the second paperboard insert, or by lifting or tearing off the cover.

As shown inFIG.5, the removable cover may be a portion of the second central portion integrally formed with the second paperboard insert and at least partly surrounded by a perforation of the second central portion.

The cover may be hingedly connected to the second paperboard insert by a hinge. By joining the cover by a hinge, the cover can easily be lifted and lowered for opening and closing respectively, of the grip opening of the second paperboard insert. This allows for an intermediate space between the first paperboard insert and the second paperboard insert to be used for storage purposes and allows easy repeated access to objects stored in the intermediate space. For example, a spoon can be stored in the intermediate space and replaced there after use of the spoon.

Like reference number denote similar features throughout the figures. Reference numbers may be omitted in some figures for better visibility, in which case reference is made to the other figures.

DETAILED DESCRIPTION

It is to be understood that the drawings are schematic and that individual components, such as layers of materials are not necessarily drawn to scale. The steps in the method of forming a packaging container1, and the packaging container1shown in the figures, are provided as examples only and should not be considered limiting to the present disclosure.

First, an exemplary embodiment of the packaging container1will be described with reference to the appended figures. Thereafter the method of manufacturing the packaging container1will be described.

As shown inFIGS.2and8, the packing container1comprises a tubular container body2defining an inner compartment28. The container body2comprises a container body wall7made of a laminate sheet material comprising a carton substrate layer, and comprises a first end3with a first end opening4and an opposite second end5with a second end opening6. The container body wall7has an inner surface8facing the inner compartment28in the packaging container1and an outer surface9facing away from the inner compartment28. The first end opening4is closed by a first paperboard insert12acomprising a first central portion121acovering the first end opening4. The first paperboard insert12afurther comprises a first peripheral flange portion13adirected away from the first central portion121atowards the first end opening4of the packaging container1such that an external recess122of the packaging container1is formed. The first peripheral flange portion13ais attached to the inner surface8of the container body wall7at a first attachment portion129of the container body2.

Also, as for example shown in the enlarged portion C ofFIG.14, the container body2has a weakened portion130extending along at least a portion of the circumference of the container body2, the weakened portion130is between the first attachment portion129and the second end5of the container body2. In this embodiment, the weakened portion130comprises a perforation extending around the full circumference of the packaging container1, but in other embodiments, any other suitable type of weakening may alternatively be used instead, such as a crease line or a tear-off tape. In this embodiment, the perforation extends only partially through the container body wall7, such that a sealing layer on the inside of the paperboard is not perforated.

As shown inFIG.14, the first peripheral flange portion13apreferably extends past the weakened portion130, such that a lid comprising said first paperboard insert12acan be guided by the peripheral flange portion into the container body2at closing of the lid of the packaging container1(once the packaging container1has been opened by tearing off the lid at the weakened portion130of the container body2).

The above-mentioned structure of the container body2is common of all embodiments of the packaging container1of the present disclosure and corresponds to container body2shown inFIG.6.

As shown inFIGS.2and8, the packaging container1further comprises a second paperboard insert12bpositioned in the external recess122and covering the first end opening4. The second paperboard insert12bcomprises a second central portion121band a second peripheral flange portion13bdirected away from the second central portion121btowards the first end opening4of the packaging container1. The second peripheral flange portion13bis attached to the inner surface8of the container body wall7. Alternatively, the second peripheral flange13bcould be attached to the first peripheral flange13aof the first paperboard insert12awithout departing from the scope of the disclosure.

In the illustrated embodiment, the first paperboard insert12aand the second paperboard insert12bboth attach to the container body wall7. At opening of the packaging container1, a user grabs the first end3of the container body2, typically by grabbing the second peripheral flange portion13bof the second paperboard insert12b, and pulling such that the container body wall7separates at the weakened portion130. Since the weakened portion130is between the first attachment portion129and the second end5of the container body2, the first paperboard insert12aand the second paperboard insert12btogether form a lid comprising the torn off portion (e.g., upper portion) of the container body wall7that separates at the weakened portion. The combination of the two paperboard inserts12a,12bimproves rigidity of the lid and makes the lid easier to handle during and after separation of the lid from the rest of the container body2.

As shown inFIGS.2and8, the second central portion121bof the second paperboard insert12bcomprises a recessed portion123adjacent the container body wall7. In other embodiments, more than one such recessed portion123may be provided.

The recessed portion123adjacent the container body wall7makes it easier for the user to grab hold of the lid when tearing it off the rest of the container body2by increasing the surface area available to be gripped by the user. The recess also provides a visual indication for the user where to grab, thus making it even easier to remove the lid, since pulling the lid off the rest of the container will be more difficult if pulled at an arbitrary location.

The second paperboard insert12bis formed from a paperboard blank131a, shown inFIG.3. The paperboard blank131acomprises a central portion132ahaving a shape and size corresponding to the shape and size of the first end opening4of the container body2. The central portion is indicated by a dashed line inFIG.3. The second paperboard insert12balso comprises a peripheral portion133asurrounding the central portion132a. The peripheral portion133aof the paperboard blank131ais enlarged adjacent a portion of the paperboard blank where the recessed portion123is formed.

By enlarging the paperboard blank131aadjacent where the recessed portion is formed, extra material is available to form the recess without reducing the amount of material available for forming the second peripheral flange portion. This also enables attachment of the second peripheral flange portion to the container using a weld or adhesive bond extending around the circumference of the first end opening4of the packaging container1in a planar fashion.

As indicated above, the second central portion121bof the second paperboard insert12bmay in other embodiments alternatively comprise a grip opening136rather than a recessed portion123. The grip opening136may be covered by a removable cover137as shown inFIGS.4and5.

The grip opening136provides an alternative to the recessed portion123discussed above. The grip opening136enables a user to grab the lid of the packaging container1through the grip opening136, thus reaching a larger surface area of the lid to grab hold of. The grip opening136may be covered by a separate lid member or membrane, or may be covered by a portion of material made from the same paperboard blank as the second paperboard insert12bby provision of a scoring, perforation or similar extending at least partly around the circumference of the opening such that the user gains access to the opening by forcing the cover137into the space between the first paperboard insert12aand the second paperboard insert12b, or by lifting or tearing off the cover137.

The movable/removable cover137may be a portion of the second central portion121bintegrally formed with the second paperboard insert12band at least partly surrounded by a perforation of the second central portion121b.

The cover137may be hingedly connected to the second paperboard insert12bby a hinge139. By joining the cover137by the hinge139, the cover can easily be lifted and lowered for opening and closing respectively, of the grip opening136of the second paperboard insert12b. This allows for an intermediate space between the first paperboard insert12aand the second paperboard insert12bto be used for storage purposes and allows easy repeated access to objects stored in the intermediate space. For example, a spoon can be stored in the intermediate space to be easily accessed and replaced after use. The hinge139is typically a non-perforated portion of the second paperboard insert12b, but may in other embodiments be a piece of resilient material, such as a sheet material, attached to the cover137and to the second paperboard insert12bby adhesive or by welding.

Although the packaging container1may be produced using any suitable method, one exemplary method of producing the packaging container1will be described below with reference to the appended drawings.

The method comprises a step a) of obtaining a body blank134having a first side edge135aand a second side edge135b, said body blank134being made of a laminate sheet material comprising a carton substrate layer. Such a body blank134is schematically shown inFIG.1. The method also comprises a step b) of forming a tubular container body2from the body blank134, including a step c) of sealing together the first side edge135aand the second side edge135b. The tubular container body2defines an inner compartment28. Also, the container body2comprises a container body wall7having an inner surface8facing the inner compartment28and an outer surface9facing away from the inner compartment28. The container body2comprises a first end3with a first end opening4and an opposite second end5with a second end opening6.

As shown inFIG.9, the method further comprises a step d) of closing the first end opening4by pressing a first paperboard insert12ainto the first end opening4to a first predetermined position P1relative to the container body2, the first paperboard insert12acomprising a first central portion121acovering the first end opening4, and comprising a first peripheral flange portion13adirected away from the first central portion121atowards the first end opening4of the container1such that an external recess122of the packaging container1is formed. As shown inFIG.9, the dots representing contents of the inner compartment28of the packaging container1. The contents may alternatively be filled into the container body2from the bottom/second end5of the container body after one of or both of the paperboard inserts12a,12bhave been inserted into the container body.

The method further comprises a step e) of attaching the first peripheral flange portion13aof the first paperboard insert12ato the container body wall7. For example, a suitable type of welding may be used for said attaching.

Also, the method comprises a step f) of pressing a second paperboard insert12binto the external recess122through the first end opening4to a second predetermined position P2relative to the container body2, the second paperboard insert12bcomprising a second central portion121bcovering the first end opening4, and comprising a second peripheral flange portion13bdirected away from the second central portion121btowards the first end opening4of the container body2. The second predetermined position P2is above the first predetermined position P1in the container body2.

Further, the method comprises a step g) of attaching the second peripheral flange portion13bof the second paperboard insert12bto the container body wall7. For example, a suitable type of welding may be used for said attaching.

By additionally pressing a second paperboard insert into the external recess and attaching it to the container body wall, a double-wall lid structure is formed by the first paperboard insert12aand the second paperboard insert12b. The lid structure is more robust than the single-wall prior art lid structures formed when using only one paperboard insert12a.

The method may further comprise a step h) of deforming the second central portion121bof the second paperboard insert12bprior to attaching the second peripheral flange portion13bto the container body wall7, such that a recessed portion123of the second paperboard insert12bis formed adjacent the second peripheral flange13b, the recessed portion123being shaped such that a distance D between the second central portion121bof the second paperboard insert12band the first central portion121aof the first paperboard insert12ais reduced at the recessed portion123.

By deforming the second central portion prior to attaching the second peripheral flange portion to the container body wall, the material of the paperboard insert is free to move during deformation, such that material of a paperboard blank used to form the second paperboard insert12bis able to move from the peripheral portion of a second paperboard blank used for forming of the second paperboard insert12b, thereby mitigating stretching of the paperboard material during deformation of the second central portion of the second paperboard insert12b.

As shown inFIGS.11and13, step f) may be performed by forcing the second paperboard insert12binto the external recess122using a footprint surface53of a press tool27. The footprint surface53has a shape and size adapted to the shape and size of the first end opening4of the container body2, and has a protrusion128for forming the recessed portion123of the second paperboard insert12b. The protrusion128of the press tool27may be integrally formed with the footprint surface53of the press tool, or provided as a separate member attached to the press tool to modify the footprint surface, without departing from the disclosure.

As shown inFIGS.11,12and13, step f) may comprises positioning a guide plate125adjacent the first end opening4of the container body2such that a through cavity126of the guide plate125is aligned with the first end opening4, said through cavity126having a shape and size corresponding to the shape and size of the first end opening4of the container body2. The second paperboard insert12bis guided into the external recess122through the through cavity126of the guide plate125at the pressing of the second paperboard insert12binto the external recess122, wherein the second peripheral flange portion13bis bent between the guide plate125and the press tool27.

The guide plate125typically also comprises an alignment recess138shaped to align a paperboard blank131a,131bwith the through cavity126of the guide plate125.

The use of such a guide plate125, protects the first end3of the container body2such that deformation of the paperboard bland occurs mainly as a result of forces acting on the paperboard blank by the guide plate and the press tool, rather than between the container body wall7and the press tool27.

It should be understood that two different press tools27may be needed: one for the first paperboard insert12a, and another for the second paperboard insert12b. It can be seen that the press tool27used for the first paperboard insert12adoes not have a protrusion128for forming a recess, whilst the press tool27used for the second paperboard insert12bmay have such a protrusion128as shown inFIG.11. If no recessed portion123is in the second paperboard insert12b, the same press tool27may be used for both the first paperboard insert12aand the second paperboard insert12b.

Similarly, as shown inFIGS.10and12, two different guide plates125may be needed: one for the first paperboard insert12aand another for the second paperboard insert12b.

The through cavity126of the guide plate125used for the second paperboard insert12bhas a recessed portion127extending the through cavity126laterally with respect to an insertion direction ID along which the second paperboard insert12bis inserted into the external recess122. The recessed portion127of the through cavity126is positioned adjacent where the protrusion128of the footprint surface53passes through said through cavity126.

The recessed portion127reduces the area/edge length of the through cavity of the guide plate125on which the paperboard blank slides at deformation between the press tool27and the guide plate125, thus enabling increased local stress on portions of the paperboard blank such that the paperboard blank folds at intended locations as the second peripheral flange portion is folded to point away from the second central portion of the second paperboard insert12b.

The recessed portion127of the through cavity126has a dovetail shape.

The dovetail shape provides relatively sharp corners at the opening of the recessed portion, thereby enabling greater control of where the material of the blank folds as it is pressed through the guide plate125.

The protrusion128of the footprint surface53may comprise an outer surface portion128afacing the container body wall7when inserted into the external recess122. The outer surface portion128ahas a shape corresponding to the shape of an adjacent portion of the container body wall7when inserted into the external recess122, wherein the width W1of an opening of the recessed portion127corresponds to a width W2of the outer surface portion128aof the protrusion128of the footprint surface53. In one example, the shape of the outer surface portion128ais curved to correspond to the curved shape of the adjacent portion of the container body wall7. The outer surface portion128a, could have other shapes (e.g., straight) without departing from the disclosure.

The correspondence between the width of outer surface portion and the width of the opening of the recessed portion concentrates stress on the paperboard material of the blank, thereby improving control of where the material of the blank folds as it is pressed through the guide plate.

In other embodiments, the recessed portion127may not be needed, for example if the choice of paperboard quality used for the paperboard blanks. The recessed portion127may thus alternatively be omitted. In some embodiments, the recessed portion127may have some other suitable shape promoting a predeterminable deformation of the peripheral portion of the paperboard blanks131a,131b.

The press tool27may be configured as shown inFIGS.9,11,13and14, and corresponds to the “positioning unit” explained in further detail in U.S. Pat. No. 11,292,625 that is incorporated by reference herein for all purposes. However, any other suitable press tool could alternatively be used instead, such as a suitably shaped piston.

Also, a retaining device23is used to position and support the container body2during insertion of the paperboard inserts12a,12binto the container body2. The retaining device23can correspond to the retaining device explained in further detail in incorporated by reference U.S. Pat. No. 11,292,625.

The retaining device23thus comprises at least one through-going positioning cavity adapted to receive a portion of the container body2.

In order to achieve the above-mentioned attaching of the peripheral flange portions12a,13bof the paperboard insert to the container body2, the retaining device23comprises a welding unit, preferably arranged around the positioning cavity. The welding unit (not illustrated) is adapted to weld the paperboard inserts12a,12bto the container body2, e.g., by the welding unit comprising a coil extending around the positioning cavity. As the press tool27is expandable in a radial direction of the positioning cavity as set out herein, the respective paperboard insert12a,12bcan be pressed against the welding unit. Any suitable welding technique may be used, such as ultrasonic welding or high frequency welding, with high frequency welding being preferred.

As an alternative or a complement to welding, an adhesive may be applied to the paperboard insert before attaching it to the container body2.

The press tool27comprises a base plate49comprising or being constituted by a rigid material such as metal or a composite material, and a plunger skirt51comprising a resiliently deformable material, e.g., rubber or plastics. The plunger skirt51is located on top of the base plate49, such that it at least partly covers an upper surface54of the base plate49which upper surface54is opposite a lower footprint surface53of the base plate49.

The footprint surface53is configured to face towards the paperboard insert during application of the paperboard insert in the container body2. It is to be understood that the footprint surface53may have any other suitable shape adapted to the cross-sectional shape of the packaging container1being produced.

The plunger skirt51is transformable between an unexpanded state, seeFIG.11, and an expanded state, seeFIG.13, by relative movement in relation to the base plate49.

In the unexpanded state of the plunger skirt51, the shape of the outer contour of the plunger skirt51corresponds to that of the base plate49. Hence, in the unexpanded state, the plunger skirt51has the same substantially footprint as the base plate49.

In the expanded state, seeFIG.13, a cross-sectional area (footprint) delimited by the outer circumference of the plunger skirt51is larger than in the unexpanded state of the plunger skirt51.

The second end opening6of the container body2can be closed in a similar manner as the first end opening4.

The paperboard blanks131a,131bcould be pre-formed in a separate method step using any suitable pre-forming device to shape the paperboard blank131a,131binto a first paperboard insert12a,12band enable the first paperboard insert12a,12bto easier fit into the first end opening4, said first paperboard insert12a,12bthus obtaining much of its desired shape and any creases or crease lines before insertion into the container body2.