PACKAGING CONTAINER WITH RIM AND LID

Abstract

A paperboard packaging container for bulk solids includes a container body having a container wall extending from a container bottom edge to a container body opening and having an inner surface facing an inner compartment in the packaging container, and a lid for closing the container body opening. An upper reinforcing rim is applied at the container body opening and extends along the opening edge, defining a perimeter of a container access opening and is joined to the inner surface of the container wall by means of a weld seal which extends around the container body opening and has an upper edge including a first abutment surface arranged to abut against a second abutment surface on an inner lid surface with the lid in a closed position on the container access opening and form a tight seal between the rim and the lid with the lid in the closed position.

Claims

1. A paperboard packaging container (1) for bulk solids (34), said packaging container comprising a container body (2) comprising a container wall (3) extending from a container bottom edge (4) to a container body opening (6) in a height direction (H) of said container (1), and a closure arrangement comprising a lid (14), said container wall (3) having an inner surface (7) facing towards an inner compartment (11) in said packaging container (1) and an outer surface (8) facing away from said inner compartment (11), said container body (2) having an opening edge (5) at said container body opening (6), and an upper reinforcing rim (15) being applied to said container body (2) at said container body opening (6) said upper reinforcing rim (15) extending along said opening edge (5) and defining a perimeter of a container access opening (35), characterized in that said upper reinforcing rim (15) is joined to said inner surface (7) of said container wall (3) by means of a weld seal (20), said weld seal (20) extending around said container body opening (6); said upper reinforcing rim (15) has an extension in said height direction (H) of said container (1) and comprises a lower edge (17) facing towards said container bottom (9) and an upper edge (19) facing away from said container bottom (9); said upper edge (19) of said upper reinforcing rim (15) comprises a first abutment surface (51); said lid (14) comprises an inner lid surface (24) facing towards said container bottom (9) when said lid (14) is in a closed position on said container access opening (35) and an outer lid surface (25) facing away from said container bottom (9) when said lid (14) is in a closed position on said container access opening (35); said inner lid surface (24) comprises a second abutment surface (52); said first abutment surface (51) on said upper reinforcing rim (15) being arranged to abut against said second abutment surface (52) on said lid (14) when said lid (14) is in said closed position on said container access opening (35) and to form a seal between said upper reinforcing rim (15) and said lid (14) when said lid (14) is in said closed position over said container access opening (35).

2. A paperboard packaging container according to claim 1, wherein said upper edge (19) of said upper reinforcing rim (15) is arranged above said container body opening edge (5) in said height direction (H) of said packaging container (1).

3. A paperboard packaging container (1) according to claim 1 or 2, wherein said weld seal (20) between said upper reinforcing rim (15) and said container wall (3) is a sift-proof weld seal (20) and preferably is a gas-tight weld seal (20) and wherein said seal between said first and second abutment surfaces (51, 52) is a sift-proof seal and preferably a gas-tight seal.

4. A paperboard packaging container (1) according to any one of the preceding claims, wherein said weld seal (20) extends continuously around said container body opening (6).

5. A paperboard packaging container (1) according to according to any one of the preceding claims, wherein said packaging container (1) further comprises a frame structure (30), said frame structure (30) being applied to said packaging container (1) at said container body opening edge (5) and being mechanically connected to said upper reinforcing rim (15).

6. A paperboard packaging container (1) according to claim 5, wherein said frame structure (30) forms part of a lid component (31), said lid component further comprising a lid part (14a), said frame structure (30) and said lid part (14a) being connected by a hinge (29).

7. A paperboard packaging container (1) according to claim 5 or 6, wherein said connection between said frame structure (30) and said upper reinforcing rim (15) is a snap-in connection.

8. A paperboard packaging container (1) according to any one of the preceding claims, wherein said paperboard container (1) comprises an inner peelable or openable sealing membrane (33) forming a cross-sectional seal between an inner compartment (11) in said container body (2) and said container opening (6).

9. A paperboard packaging container (1) according to claim 8, wherein said container (1) is a gas-tight packaging container (1) and said inner peelable or openable sealing membrane (33) is a gas-tight peelable or openable sealing membrane (33).

10. A paperboard packaging container (1) according to any one of the preceding claims, wherein one or both of said first and second abutment surfaces (51,52) is constituted by resilient material.

11. A paperboard packaging container (1) according to any one of the preceding claims, wherein said closure arrangement comprises a locking arrangement (45) being configured to maintain said lid (14) in a closed position at said container access opening (35).

12. A paperboard packaging container (1) according to claim 11, wherein said locking arrangement (45) comprises a first profiled element on said lid (14) said first profiled element being configured to releasably engage with a second profiled element on said upper reinforcing rim (15) and/or on a frame structure (30) being connected to said upper reinforcing rim (15).

13. A paperboard packaging container (1) according to claim 11 or 12, wherein said locking arrangement (45) comprises a first locking element (45b) arranged on said container body (2) on said upper reinforcing rim (15), or on said frame structure (30) and a second locking element (45a) arranged on said container lid (14), said first and second locking elements (45a, 45b) being mating locking elements (45a,45b), such as female/male locking elements.

14. A paperboard packaging container (1) according to any one of the preceding claims, wherein said inner lid surface (24) is constituted by an inner gasketing lid part (14b,28).

15. A paperboard packaging container (1) according to any one of the preceding claims, wherein said upper reinforcing rim (15) has a tapering shape in a direction from said upper edge (19) of said upper reinforcing rim (15) towards said lower edge (17) of said upper reinforcing rim (15) or in a direction from said lower edge (17) of said upper reinforcing rim (15) to said upper edge (19) of said upper reinforcing rim (15).

16. A paperboard packaging container (1) according to any one of the preceding claims, wherein said weld seal (20) between said reinforcing rim (15) and said container wall (3) is formed by high frequency welding.

17. A paperboard packaging container (1) according to any one of the preceding claims, wherein an inner profile of said reinforcing rim (15) defines a shape and a size of said access opening (35), said access opening (35) being smaller than said container body opening (6) and having an opening area which is from 85% to 99% of said container body opening area (6), such as from 90% to 98% of said container body opening area or from 94% to 97% of said container body opening area.

18. A paperboard packaging container (1) according to any one of the preceding claims, wherein said container (1) comprises mating stacking members (10, 55) for allowing two or more of said packaging container (1) to be arranged in a stacked configuration, said mating stacking members (10, 55) being arranged at said container bottom (9) and at said container opening (6).

19. A paperboard packaging container (1) according to any one of the preceding claims, wherein said container is a container for pulverulent or granulated alimentary products.

20. A paperboard packaging container (1) according to any one of the preceding claims, wherein a lower reinforcing rim (10) is attached to said container body (2), at said container bottom edge (4).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The present invention will be further explained hereinafter by means of non-limiting examples and with reference to the appended drawings wherein:

[0063] FIG. 1 shows a front view of a packaging container;

[0064] FIG. 2 shows a perspective view of the packaging container in FIG. 1;

[0065] FIG. 3 shows a perspective view of the packaging container in FIG. 1 with an open lid;

[0066] FIG. 4 shows an exploded view of the packaging container in FIG. 1;

[0067] FIG. 5 shows a top view of the packaging container in FIG. 1.

[0068] FIG. 5A shows a cross-section taken along the line A-A in FIG. 5;

[0069] FIG. 5B shows a cross-section taken along the line B-B in FIG. 5;

[0070] FIG. 5C shows a detail of a container body edge with an attached upper reinforcing rim and a lid component taken at C in FIG. 5A;

[0071] FIG. 5D shows a detail of a container body edge with an attached upper reinforcing rim and a lid component taken at D in FIG. 5A;

[0072] FIG. 5E shows a detail of a container body edge with an attached upper reinforcing rim and a lid component taken at E in FIG. 5B; and

[0073] FIG. 6A-6C show alternative packaging body foot-prints.

DETAILED DESCRIPTION

[0074] It is to be understood that the drawings are schematic and that individual components, such as layers of material are not necessarily drawn to scale. The packaging container, reinforcing rim and lid component shown in the figures are provided as examples only and should not be considered limiting to the invention. Accordingly, the scope of the invention is determined solely by the appended claims.

[0075] With reference to FIGS. 1-4, and FIG. 5A there is shown a paperboard packaging container 1 for pourable or scoopable bulk solids. The particular shape of the container 1 shown in the figures should not be considered limiting to the invention. Accordingly, the paperboard packaging container according to the invention may have any useful shape or size. By way of example, further non-limiting container body foot-prints are shown in FIG. 6.

[0076] The packaging container 1 comprises a container body 2 formed by a tubular container wall 3 including a front wall portion 3a, a rear wall portion 3b and two side wall portions 3c, 3d. The container wall 3 extends from a container body bottom edge 4 to a container body opening edge 5 at a container body opening 6 in a height direction H of the packaging container 1. The container wall 3 has an inner surface 7 facing towards an inner compartment 11 in the packaging container 1 and an outer surface 8 facing away from the inner compartment 11 and being exposed to the exterior of the packaging container 1. A bottom disc 9 is positioned at the bottom edge 4 of the container body 2. The container body 2 is made from paperboard material as defined herein. The container body 2 may be formed by bringing together the side edges of a web of paperboard causing the material to assume a tubular shape, where after the side edges are sealed together. Sealing of the side edges may be made by any suitable method as known in the art, such as by welding or gluing, with welding being preferred. Sealing of the side edges of the container body web may involve using a sealing strip, as known in the art. The bottom disc 9 may be made from paperboard, metal, plastic, or from any suitable combination of such materials as known in the art.

[0077] The container body bottom edge 4 is reinforced by a plastic bottom rim 10 which is applied to the inner surface 7 of the container wall 3, between the bottom disc 9 and the container body bottom edge 4 and which has an outwardly directed flange 12 which covers the container body bottom edge 4 and forms a bottom edge 13 of the packaging container 1. The bottom rim 10 reinforces the container body paperboard bottom edge 4, stabilizes the shape of the container body 2 and protects the container body bottom edge 4 from mechanical deformation. The plastic bottom rim 10 also serves as a protective barrier against water and other fluids which may be present on a surface on which the packaging container is placed. The bottom rim 10 delimits a downwardly open space between the bottom disc 9 and the bottom edge 13 of the packaging container 1 which may be used to accommodate stacking elements arranged at an upper end of another packaging container when stacking two or more packaging containers on top of each other.

[0078] As an alternative to a plastic bottom rim, the bottom edge of the packaging container may be formed by a rolled edge of the paperboard container body, or may be provided by a simple, non-rolled join between the bottom disc 9 and the container body 2.

[0079] The paperboard packaging container 1 is provided with a closure arrangement comprising a lid 14 and an upper reinforcing rim 15 extending along the container body opening edge 5 and defining a perimeter of a container access opening 35 which is smaller than the container body opening 6 which is defined by the upper edge 5 of the container body 2.

[0080] The upper reinforcing rim 15 is preferably a plastic rim, most preferably a thermoplastic rim and is attached to the inner surface 7 of the container body wall 3 at the container body opening 6. The upper reinforcing rim 15 has an extension in the height direction, H, of the container 1 and has a lower rim part 16 with a lower rim edge 17 facing towards the container bottom 9 and an upper rim part 18 with an upper rim edge 19 facing away from the container bottom 9. The upper reinforcing rim 15 extends around the full periphery of the container body opening 6. The upper rim part 18 protrudes upwards in the height direction, H, above the container body opening edge 5, whereby the upper edge 19 of the upper reinforcing rim 15 is arranged above the container body opening edge 5 in the height direction, H, of the packaging container 1.

[0081] The upper reinforcing rim 15 is joined to the inner surface 7 of the container wall 3 by means of a weld seal 20 extending around the container opening 6. The weld seal 20 preferably extends continuously around the container body opening 5 and is a sift-proof weld seal and is preferably also a moisture proof weld seal and most preferably a gas-tight weld seal.

[0082] The weld seal 20 is formed by supplying energy to heat and locally soften or melt one or more thermoplastic component in a thermoplastic rim 15 and/or in a coating or film on the inner surface 7 of the container body wall 3 and by pressing the reinforcing rim 15 and the container wall 3 together in a direction perpendicular to the container wall 3. The temperature and pressure can be controlled and adjusted to form a strong and tight seal without damaging the welded components. The thermoplastic material used to create the weld seal 20 may be provided by a fully or partly thermoplastic reinforcing rim 15, by a thermoplastic film or coating on the inner surface 7 of the container wall 3, or by both a fully or partly thermoplastic reinforcing rim and by a thermoplastic film or coating on the inner surface 7 of the container wall 3. A plastic reinforcing rim 15 is preferably made from thermoplastic material which allows it to be thermoformed, e.g. by injection molding. An injection molding process may be used to form plastic components having different polymer compositions in different parts of the plastic component. By way of example, the surface of a plastic reinforcing rim which is welded to the container body may be formed from a polymer composition having a lower softening and melting point than other parts of the reinforcing rim. Moreover, an abutment surface on the upper reinforcing rim 15 may be formed from a resilient thermoplastic polymer. Any suitable welding technique may be used, such as ultrasonic welding or high frequency welding, with high frequency welding being preferred.

[0083] The lid 14 is formed from an outer lid part 14a and an inner lid part 14b. The outer lid part 14a is a profiled part with a three-dimensional shape providing an upper outer surface 25 of the lid 14. As is shown in FIG. 4, the outer lid part 14a has an inner surface 26 comprising a pattern of reinforcing ribs 27. The inner lid part 14b is a planar disk. The inner lid part 14b has an inner lid surface 24 which faces towards the bottom disc 9 when the lid 14 is closed on the container access opening 35.

[0084] The outer lid part 14a is connected by a hinge 29 to a frame structure 30, the lid 14 and the frame structure 30 together forming a lid component 31. With reference to FIG. 5D, the hinge 29 is shown to be a live hinge, formed integrally with the upper lid part 14a and the frame structure 30 as a flexible connection between the upper lid part 14a and the frame structure 30. As set out herein, the illustrated hinge is only intended as a non-limiting example and it should be understood that any other type of functional hinge may be used for the connection between the frame structure and the lid. Moreover, the lid may be of the removable kind, without any permanent connection to the frame structure.

[0085] The frame structure 30 is applied to the packaging container at the container body opening edge 5 and is mechanically attached to the upper reinforcing rim 15 by a snap-on connection. The frame structure 30 is attached to the upper reinforcing rim 15 after the reinforcing rim 15 has been welded to the inner surface 7 of the paperboard container wall 3. Accordingly, the frame structure can be attached at a late stage in a process for assembling and filling the packaging container as disclosed herein. The frame structure 30 is applied to the upper reinforcing rim 15 by pressing the frame structure 30 down over the upper edge 19 of the upper reinforcing rim 15 until the frame structure 30 locks in place on the upper reinforcing rim 15 as is described in more detail herein with reference to FIG. 5E. When the frame structure 30 has been attached to the upper reinforcing rim 15, it can only be removed again by breaking or damaging the connection.

[0086] The interior compartment 11 shown in FIGS. 3, 5A and 5B is sealed with a fully or partly removable sealing membrane 33 which is applied over the packaged goods 34 and which is sealed to the container body wall 3. The removable sealing membrane 33 may be attached to the container wall either from the top end of the container body 2 or from the bottom end of the container body 2. In order to gain a first access to the packaged goods, a user needs to open the lid 14 and expose the packaged goods 34 by fully or partly removing the sealing membrane 33. The sealing membrane 33 may be arranged to be peeled away from the wall 3 of the container body 2 or may be arranged with means for breaking the membrane 33 so that it can be at least partly removed from the opening 6, 35. Such means may be in the form of one or more predefined weakenings, such as perforations or a cut partly through the membrane. When the membrane is of the tear-open type, a narrow edge part of the sealing membrane may be left at the inner surface 7 of the container wall 3. Any such remaining part of the sealing membrane should preferably not be so large so that it extends into the access opening which is defined by the inner perimeter of the upper reinforcing rim. Accordingly, it may be preferred that a remaining membrane part has an extension perpendicular to the height direction H of the packaging container of at most 7 millimeters such as from 1-6 millimeters, from 2-5 millimeters or from 3-4 millimeters. It may be preferred that the inward extension of a remaining membrane part is 4 millimeters or less. The sealing membrane 33 is an optional feature of the disclosed packaging container 1 and may be omitted.

[0087] Once the sealing membrane 33 has been removed, it is sufficient to open the lid 14 in order to gain access to the packaged goods 34 in the interior compartment 11 through the access opening 35. As is seen in FIG. 3, which reveals the inside of the upper reinforcing rim 15, the area of the access opening 35 is defined by an inner perimeter 28 or inner contour of the upper reinforcing rim 15. As the upper reinforcing rim 15 is applied on the inner surface 7 of the container body wall 3 and adds thickness to the body wall in an inward direction, the area of the access opening 35 is always smaller than the area of the container body opening 6. The upper reinforcing rim 15 which is shown in FIGS. 3 and 4 has a combined scraper bar and scoop holder 40 which extends across a corner portion of the reinforcing rim 15. The combined scraper bar and scoop holder 40 is provided with a scraping edge 41 for scraping off excess scooped-up contents from a scoop or spoon and an eye 42 for receiving and holding a hook element 43 arranged at the end of a scoop or spoon 44. The combined scraper bar and scoop holder 40 is an optional element of the packaging container 1 as disclosed herein.

[0088] When the packaging container 1 is open, a desired quantity of the packaged goods 34 may be removed from the packaging container 1 through the access opening 35 either by hand, by using a scoop or a spoon, or by pouring. If a scoop or spoon is used, it may be a scoop or spoon which is provided together with the packaging container. The scoop or spoon may initially be placed on the sealing membrane 33, if present, may be removably attached to the inner lid surface 26 or may be attached to a scoop holder 40 as shown in FIG. 3. The scoop or spoon 44 may be provided with a hook element 43 which hook element is arranged to cooperate with the eye 42 in a combined scraper bar and scoop holder 40, as set out above whereby the scoop or spoon 44 may be attached to the reinforcing rim 15 such that the handle on the scoop or spoon is prevented from falling down into the contents in the packaging container between dispensing occasions. Users may find it more appealing and hygienic to be able to remove the scoop from the container without having to dig it out from the remaining contents in the packaging container. An advantage with combining the holding function with a scraper function, is that the combined scraper bar and scoop holder 40 intrudes minimally on the open area of the access opening 35. Accordingly, even if provided with the combined scraper bar and scoop holder 40 as disclosed herein, the packaging container has a large access opening which greatly facilitates removal of the contents from the packaging container either by scooping or by pouring.

[0089] The access opening 35 may have an opening area which is from 85% to 99% of the opening area of the container body opening 6, such as from 90% to 98% of the container body opening area or from 94% to 97% of the container body opening area.

[0090] A tight closure between the lid 14 and the container body 2 is provided by a first abutment surface 51 on the upper rim edge 19 and a corresponding second abutment surface 52 arranged on the inner lid surface 24. The first abutment surface 51 on the upper reinforcing rim 15 is arranged to abut against the second abutment surface 52 on the lid 14 when the lid is in the closed position on the container access opening 35 and to form a seal between the upper reinforcing rim 15 and the lid 14.

[0091] In order to keep the lid 14 secured in the closed position between dispensing occasions, the closure arrangement of the packaging container 1 may further comprise a locking arrangement 45, as seen in FIGS. 5A and 5C. The locking arrangement 45 may comprise mating locking elements 45a, 45b, as illustrated in FIG. 5C. A male locking element 45a is arranged on the lid 14 and a female locking element 45b is arranged on the frame structure 30 which is indirectly attached to the container body 2 by being mechanically attached to the upper reinforcing rim 15. The male locking element 45a is constituted by one or more protrusions, such as one or more knobs or ribs arranged on a locking flap 46 and the female locking element 45b is constituted by one or more corresponding cavities or grooves arranged on the frame structure 30. The locking arrangement 45 is preferably designed such that it exerts a force on the connection between the lid 2 and the upper rim edge 19 by pressing the first and second abutment surfaces 51, 52 together.

[0092] The paperboard packaging container 1 shown in FIGS. 1-4 may be stacked on another such packaging container 1 by resting the bottom rim 10 on a ledge 55 at the periphery of the upper outer lid surface 25, the bottom rim 10 and the ledge 55 thus forming mating stacking members. As can be seen in FIGS. 1, 2, 5A and 5D, the portion of the lid 14 inside the ledge 55 forms a protrusion from the plane in which the ledge 55 is arranged, which plane may be considered to be a horizontal base plane for the lid 14. When one packaging container 1 is stacked upon another identical packaging container, the protruding portion of the lid 14 is fully accommodated in the space defined by the bottom disc 9 and the bottom rim 10 at the bottom of an upper stacked packaging container. Accordingly, the packaging containers can be safely stacked on top of each other in a stable and horizontal arrangement even if the lids 14 have a three-dimensional shape.

[0093] The lid components 31 are also separately stackable when in a closed position, by resting the lower edge of one frame structure 30 on a ledge on the upper outer lid surface of the upper lid part 14a.

[0094] The arrangement of the lid component 31 on the upper reinforcing rim will now be described in greater detail. FIG. 5A shows a cross-section taken along the line A-A through the packaging container shown in FIG. 5, i.e. through the locking arrangement 45 at the front of the packaging container 1 and through the hinge between the upper lid part 14a and the frame structure 30 at the rear of the packaging container 1. In these particular areas, there is no mechanical engagement between the upper reinforcing rim 15 and the lid component 31. FIG. 5B shows a cross-section taken along the line B-B through the packaging container shown in FIG. 5, i.e. through a corner portion of the packaging container. FIGS. 5C, 5D and 5E show details taken from FIGS. 5A and 5B of the combined frame structure 30 and the upper reinforcing rim 15 in the area of the locking arrangement 45, in the area of the hinge 29 and in a part free of such additional features.

[0095] With particular reference to FIG. 5E which illustrates the coupling between the upper reinforcing rim 15 and the frame structure 31, the lower part 16 of the upper reinforcing rim 15 is permanently attached to the inner surface 7 of the container wall 3 with the weld seam 20, such that the lower edge 17 of the reinforcing rim 15 is facing downward in the height direction H and with the upper part 18 of the reinforcing rim 15 protruding past the upper edge 5 of the container wall 3. The upper edge 19 of the reinforcing rim 15 forms a first abutment surface 51 which abuts against a second abutment surface 52 on the inner surface 24 of the inner lid part 14b. Accordingly, the lid 14 closes on the packaging container 1 by forming a tight seal between the upper reinforcing rim 15 and the inner surface 24 of the lid 14 while the frame structure 30 provides attachment for the lid 14, and can be shaped and configured for carrying hinge elements, locking elements and stacking means without any concern for providing a tight closure between the lid and the container. The weld seal 20 forms a tight contaminant-free seal on the inside of the container 1 and ascertains that the seal between the closed lid 14 and the container compartment 11 is a tight seal which means that the packaging container can be tightly sealed also after a first opening of the packaging container.

[0096] FIG. 5E shows the upper reinforcing rim 15 with an outwardly protruding ridge 58 which is arranged to engage with a locking flange 59 at the upper edge of the frame structure 30 when the frame structure 30 has been pressed down over the upper reinforcing rim 15. Once the frame structure 30 has been completely pressed down on the upper reinforcing rim and the locking flange 59 on the frame structure 30 has been moved past the ridge 58 on the upper reinforcing rim 15 and snapped into a locking engagement with the ridge 58, the frame structure 30 will remain mechanically attached to the reinforcing rim 15. The only way the snap-fitted frame structure 30 can be removed from the reinforcing rim 15 is by forcefully breaking or destroying the connection.

[0097] The shape of the packaging container as disclosed herein is not limited to the generally rectangular shape with rounded corners which is shown in FIGS. 1-3. Further non-limiting examples of useful shapes are shown in FIGS. 6a-6c. FIG. 6a shows a container body 2a having a generally D-shaped footprint with an outwardly curved front wall portion 3a with a radius of curvature of 120 millimeters, curved corners having a radius of curvature of 25 millimeters at the front wall portion 3a and a radius of curvature of 20 millimeters at the rear wall portion 3b, planar side wall portions 3c, 3d and a planar rear wall portion 3b.

[0098] The container body 2b in FIG. 6b has curved corners with a radius of curvature of 20 millimeters, curved front and rear wall portions 3a, 3b with a radius of curvature of 150 millimeters and planar side wall portions 3c, 3d.

[0099] The container body 2c in FIG. 6c has curved corners with a radius of curvature of 20 millimeters, slightly curved front and rear wall portions 3a, 3b with a radius of curvature of 400 millimeters and slightly curved side wall portions 3c, 3d with a radius of curvature of 200 millimeters. Accordingly, all the container body wall portions 3a-3d in FIG. 6c are slightly outwardly curved. A container body having the foot-print shown in FIG. 6c has improved shape stability and rigidity as compared to conventional packaging containers having planar walls. The radii of curvature of the upper and lower body wall edges govern the curvature of the container walls and may be selected to have a large radius of curvature in the order of from 200 millimeters to 700 millimeters, such as from 300 to 500 millimeters such that the container walls are provided with a near-planar shape, implying that the container walls are perceived by a human being as being planar when looking at the container from a normal viewing distance such as when the packaging container is placed on a shelf.

[0100] The rigid plastic upper reinforcing rim 15 as disclosed herein which is welded to the inner surface 7 of the container body wall 3 contributes to shape and stabilize the container body opening edge 5 and also ascertains that the container body wall is provided with a desired shape and in particular that the container body wall can be imparted with a predetermined and stable curvature. In a corresponding manner, when the packaging container as disclosed herein is provided with a bottom rim 10, the bottom rim 10 further contributes to shape and stabilize the container body bottom edge 4.

[0101] Any plastic component in the packaging container as disclosed herein such as an upper and a lower reinforcement rim, a lid component, and a frame structure may be formed from thermo-formable or moldable plastic materials, e.g. by injection molding. Injection molding is particularly suitable for producing plastic components having a three-dimensional structure, such as the lid component 31 shown in FIG. 4.

[0102] It should be understood that the lid construction shown herein is optional to the packaging container of the claimed invention. In particular, a lid for a packaging container as disclosed herein may be made without an inner reinforcing framework, may be made as a single part, may be integrally formed with a plastic frame structure and a hinge, as shown in FIG. 4 or may be formed as a separate part which may be provided with a hinge element for creating a hinged connection to a container body or to a separate frame structure which is attached to the upper reinforcing rim 15.

[0103] It is also to be understood that the outer three-dimensional shape of the lid may be different from that shown in the figures.

[0104] A packaging container as disclosed herein may be produced and filled by forming a tubular container body from a paperboard sheet, welding an upper reinforcing rim to the inner surface of the paperboard container body wall at an opening end of the container body and applying a sealing membrane to the inner surface of the container body wall across the container body opening and at a distance from the upper reinforcing rim so as to close the container body opening. The packaging container is thereafter turned upside-down and filled with pulverulent contents from the bottom end of the container body, whereafter the bottom end of the container body is closed by a bottom disc and, optionally, a reinforcing bottom rim is applied to the bottom end of the container body. The filled packaging container may then be provided with a frame structure which is attached to the upper reinforcing rim either mechanically or by means of adhesive. A lid is also attached over the container body opening such that it forms a tight closure with the upper reinforcing rim. The lid can be provided as a separate component or as an integral part of a lid component which also comprises the frame structure.

[0105] It is an advantage of a lid construction as disclosed herein that a lid component or a frame structure can be attached to the upper reinforcing rim after the container has been filled and closed around the contents. In this manner, the risk that the lid component or frame structure is damaged in the production and filling process is minimized. Furthermore, by attaching the lid component or frame structure at a late stage in the process, the packaging container can be filled from the bottom end of the container body, which means that a sealing membrane can be applied in the packaging container before the container is filled. An advantage with applying the sealing membrane in the packaging container before the packaging container is filled with pulverulent material is that there is no risk that the seal between the membrane and the container wall is contaminated by the pulverulent material. Furthermore, there is no risk that any of the packaged pulverulent material will end up outside the sealing membrane, in the space between the lid and the sealing membrane, which may happen if the sealing membrane is applied after filling of the packaging container. A user opening a new packaging container for a first time and finding some of the contents outside the sealing membrane would consider the container to be less hygienic and reliable than a container in which the space between the sealing membrane and the lid is completely clean.