Paperboard Packaging Container And Lid

Abstract

The present disclosure provides a method of forming a paperboard packaging container comprising a tubular paperboard container body, a container bottom and a container lid. The container body comprises a container body abutment edge at the container opening. The container body has an inner surface facing towards an inner compartment in the packaging container and an outer surface facing away from the inner compartment. The container lid comprises a lid collar having an abutment edge adapted for abutting against the container body abutment edge, and a lid plug-in portion. The plug-in portion has a side surface extending in the longitudinal direction and faces the inner surface of the container body, when the container lid is in a closed position. The lid collar is made of the same material as the container body and the lid collar is delimited from the container body by a slit or by weaking means.

Claims

1. A method of producing a paperboard packaging container, the method comprising: a) bending a paperboard sheet material into a tube having a longitudinal direction, a radial direction perpendicular to said longitudinal direction, and a circumferential direction and closing said tube in said longitudinal direction by joining overlapping or abutting side edges of said paperboard material, said closed tube having a top end and a bottom end and comprising a container body portion and a lid collar portion, said lid collar portion being arranged at said top end and being delimited from said body portion by a dividing line extending in said circumferential direction between said body portion and said lid collar portion; b) imparting a predetermined cross-sectional shape to said tube; c) closing said tube at said top end by pressing a transport closure into said tube at said top end or at said bottom end, said transport closure having a transport closure peripheral flange being flexed towards said top end or towards said bottom end, said transport closure being a partially removable closure; d) attaching said transport closure peripheral flange to an inner surface of said container body portion at said top end of said tube; e) pressing a paperboard top disc into said tube at said top end, said top disc having a peripheral flange being flexed towards said top end in said longitudinal direction, said flexed peripheral flange extending in said longitudinal direction across said dividing line with an attachment portion positioned at said lid collar portion and a plug-in portion positioned at said container body portion; f) attaching said attachment portion of said peripheral flange of said paperboard top disc to an inner surface of said lid collar portion of said tube; g) forming a locking arrangement by providing said container body portion with a first locking element and providing said plug-in portion with a second locking element, said first and second locking elements being mating locking elements comprising a protrusion and a recess, said mating locking elements being formed by physically deforming said paperboard material in said container body portion and said plug-in portion in said radial direction; h) arranging a slit or weakening means extending along from 10-100% of said dividing line, said slit or weakening means being arranged along said dividing line before or after forming said tube.

2. The method according to claim 1, further comprising the step of i) filling bulk solids into said container body portion.

3. The method according to claim 2, further comprising the step of j) closing said bottom end of said tube.

4. The method according to claim 3, wherein said filling step i) is carried out by filling from said top end after closing said bottom end in step j) and before closing said top end in step c).

5. The method according to claim 3, wherein said filling step i) is carried out by filling from said bottom end after attaching said transport closure in step d), and before said closing step j).

6. The method according to claim 3, wherein said filling step i) and said closing step j are sequentially performed after steps a)-h) on a production line separate from steps a)-f).

7. The method according to claim 1, wherein said slit or weakening means is formed simultaneously with forming said mating locking elements of said locking arrangement.

8. The method according to claim 1, wherein said predetermined cross-sectional shape is a rectangular shape or a modified rectangular shape.

9. The method according to claim 1, wherein said step e) comprises simultaneously forming said mating locking elements by embossing a part of said container body portion together with a side surface portion of said plug-in portion between a male shaping tool and an anvil having a corresponding recess, thereby forming said mating male and female locking elements.

10. The method of claim 9, wherein the side surface portion of the plug-in portion comprises at least a portion of the peripheral flange.

11. The method of claim 10, wherein the lid collar portion is folded over the peripheral flange so that the lid collar portion is in face-to-face contact with an interior surface of the peripheral flange and with an exterior surface of the peripheral flange.

12. The method of claim 1, wherein a hinge is provided between the lid collar portion and the container body so that the lid collar portion forms a lid of the container that is openable by pivoting the lid about the hinge.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0094] The present invention will be further explained hereinafter by means of non-limiting examples and with reference to the appended drawings wherein:

[0095] FIG. 1a illustrates a packaging container according to the present disclosure, with the container lid in an open position;

[0096] FIG. 1b illustrates a packaging container according to the present disclosure, with the container lid in a closed position, with a part of the packaging container illustrated in a cross-section view;

[0097] FIGS. 2a-k show schematically a process for producing and filling the packaging container in FIG. 1;

[0098] FIG. 3 illustrates a cross-sectional view of the packaging container according to line III-III in FIG. 1b.

DETAILED DESCRIPTION

[0099] 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 packaging containers shown in the figures are provided as examples only and should not be considered limiting to the invention. Accordingly, the scope of invention is determined solely by the scope of the appended claims.

[0100] FIGS. 1a and 1b illustrate a paperboard packaging container 1 for bulk solids according to the present disclosure. The particular shape of the container 1 shown in the figures should not be considered limiting to the invention. Accordingly, a packaging container produced according to the invention may have any useful shape or size.

[0101] FIG. 1a illustrates the paperboard packaging container 1 in an open position and FIG. 1b illustrates the paperboard packaging container 1 in a closed position wherein a part of FIG. 1b is a cross-sectional view.

[0102] The paperboard packaging container 1 comprises a tubular paperboard container body 3, a container bottom 4 and a container lid 5. The container body 3 extends in a longitudinal direction (L) of the container 1 from a bottom end 10 of the container body 3 to a container opening 7. The container body 3 comprises a container body abutment edge 8 at the container opening 7. The container body 3 has an inner surface 12 facing towards an inner compartment 14 in the packaging container 1 and an outer surface 13 facing away from the inner compartment 14.

[0103] In FIG. 1a the container body having a cuboid shape is depicted. The paperboard container has a front wall portion 36, a rear wall portion 37, side wall portions 38,39 and curved corner portions connecting the wall portions. The curved corner portions have a radius of curvature of between 15 and 30 mm.

[0104] The front and rear wall portions 36, 37 may have an an outwardly curved shape with a radius of curvature of from 30-400 mm, while the side wall portions are substantially planar.

[0105] The container lid 5 comprises an outer circumferential lid collar 18 having a lid abutment edge 19, which is adapted for abutting against the container body abutment edge 8, and a lid plug-in portion 15. The container lid 5 is also provided with a grip tab 28.

[0106] The plug-in portion 15 has a side surface 16 which extends in the longitudinal direction (L) and faces the inner surface 12 of the container body 3 when the container lid 5 is in a closed position. The plug-in portion 15 further comprises a main surface 17 being located at a distance from the container body abutment edge 8 when the container lid 5 is in a closed portion such that the plug-in portion 15 forms a plug extending downwards towards the container bottom 4.

[0107] The paperboard packaging container 1 is furthermore provided with a locking arrangement for retaining the container lid 5 in a closed position after closure of the lid 5. The locking arrangement according to FIG. 1 comprises a first locking element 21 in the form of a recess, provided on the inner surface 12 of the container body 3, and a second locking element 22 in the form of a mating protrusion, provided on the side surface 16 of the lid plug-in portion 15. However, the first locking element 21 may also be in the form of a protrusion and the second locking element 22 in the form of a recess, wherein the protrusion and the recess are matching such that the protrusion projects into the recess when the container lid 5 is in a closed position.

[0108] The first and second locking elements 21, 22 are arranged such that when the container lid 5 is in the closed position the protrusion is in engagement with the recess, i.e. the first locking elements 21, provided on inner surface 12 of the container body 3, is provided with the same distance from the container body abutment edge 8 as the second locking element 22, provided on the side surface 16 of the plug-in portion 15, is provide from lid abutment edge 19.

[0109] The mating locking elements 21, 22 illustrated in FIGS. 1a and 1b are in the form of an elongated continuous protrusion and an elongated continuous recess provided along substantially 100% of the periphery of the inner surface 12 of the container body 3 and the side surface 16 of the plug-in portion 15, respectively.

[0110] The packaging container 1 could also be provided with two or more of the locking arrangements, such that two or more of the first locking element 21 and two or more of the second locking element 22, would be arranged in parallel, spaced apart in the longitudinal direction, continuously or discontinuously, along the periphery of the inner surface 12 of the container body 3 and along the periphery of the side surface 16 of the plug-in portion 15, respectively.

[0111] The container body abutment edge 8 and the lid abutment edge 19 are in FIG. 1a are perpendicular to the wall of the container body 2 and have flat surfaces.

[0112] The container lid 5 is opened by pivoting the container lid about a hinge 27 provided between the container lid 5 and the container body 3. The hinge 27 is provided at one of the side wall portions.

[0113] The lid collar in FIG. 1b is delimited from the container body by a slit 20 or by weakening means 20, extending along at least 75%, of the container body periphery for allowing the lid collar to be fully or partially separated from the container body at the abutment edges 8,19.

[0114] In a packaging container 1 as disclosed herein, the lid 5 may be arranged to be completely removed when opening the container 1. When the container lid 5 is a completely removable lid, the container lid 5 is free from permanent connections to the container body 3. For the lid collar 18, and thus the container lid 5, to be fully separable from the container body, the slit 20 or the weakening means 20 should extend along 100% or substantially 100% of the container body 3 periphery.

[0115] The paperboard packaging container 1 is in FIGS. 1a and 1b provided with a partly removable transport closure 29 being attached to the inner surface 12 of the container body 3 at the transport closure peripheral flange 35. The transport closure 29 is removed by a user in order to gain initial access to the packaged content, leaving the peripheral flange 35 still attached to the inner surface 12 of the container body 3. The peripheral flange 35 acts as a reinforcement of the container opening 7 and stabilizes the shape of the container opening 7 such that the container 1 can be repeatedly opened and reclosed without the shape of the container opening 7 deteriorating over time. The stabilizing residual peripheral flange 35 contributes to maintaining a distinct closure even after the container 1 has been opened and closed multiple times. The transport closure 29 is provided at sufficient distance from a container body abutment edge 8 at said container opening 7 to allow the container lid 5 comprising the plug-in portion 15 to be in a closed position, meaning that this distance should be equal to or larger than the height of the plug-in portion 15.

[0116] As may be seen in FIG. 1b the container bottom 4 is in the form of a bottom disc provided in the bottom end 10, the bottom disc having a peripheral flange being flexed towards the bottom end 10 in the longitudinal direction (L). The attachment of the flange may be performed by gluing or welding, for instance with high frequency weld to the inner surface 12 of the container body 3. The bottom end edge is folded inwards over the bottom disc flange.

[0117] A paperboard packaging container 1 as shown in figs. 1a and 1b may be produced by the method illustrated in FIGS. 2a-2k. The method involves bending a paperboard sheet material 2, shown in FIG. 2a, into a tube 2 by bending together the side edges 30,31 of the paperboard sheet material 2, thus causing the material to assume a tubular shape as shown in FIGS. 2b and 2c. The tube 2 has a longitudinal direction L, a radial direction R perpendicular to the longitudinal direction L, and a circumferential direction C. The side edges 30,31 of the paperboard sheet material 2 are then sealed together such that the tube 2 is closed in the longitudinal direction L. The side edges 30,31 may be joined overlapping or with the side edges 30,31 abutting. The 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. In the process shown in FIG. 2, and more specifically in FIG. 2c, the side edges 30,31 of the container body sheet 2 are sealed using a sealing strip 34. The use of a sealing strip 34 is optional to the invention.

[0118] The bottom end is closed by a container bottom 4 in the form of a bottom disc. However, the closure may also be replaced by a folded bottom portion, as known in the art.

[0119] The resulting closed tube 2 has a top end 11 and a bottom end 10 and comprises a container body portion 3 and a lid collar portion 18, the lid collar portion 18 being arranged at the top end 11 and being delimited from the body portion 3 by a dividing line extending in the circumferential direction C between the body portion 3 and the lid collar portion 18. The dividing line 20 may be an imaginary line delimiting the tube 2 in a body portion 3 and a lid collar portion 18 which are to form the container body 3 and lid collar 18 in the method according to this disclosure. However, the paperboard sheet material 2 may also be provided with weakening means 20 before being bent into a tube 2 such that the weakening means 20 co-extends with the dividing line 20 delimiting the tube 2 in a body portion 3 and a lid collar portion 18 which are to form the container body 3 and lid collar 18 on the packaging container 1 according to the present disclosure.

[0120] FIG. 2d illustrates introducing the container body to a filling station for filling of the container body portion 3 with bulk solids through the opening at the top end 11. The filling step of the container body portion 3 may either be made by filling the container body portion 3 from the top end 11 after the bottom end 10 has been closed, or alternatively from the bottom end 10 after closing of the tube 2 at the top end 11. In FIG. 2e, a transport closure 29 is attached to the inner surface of the container body portion 3 at the top end 11 of the tube 2. The transport closure 29 is partially removable by means of a pull-tab.

[0121] FIG. 2f-g illustrates closing of the tube 2 at the top end 11 by applying a paperboard top disc 23 into the tube 2 at the top end 11. The size ratio of said top disc 23 surface area to the surface area of the opening of the tube 2 at the top end 11 is at least 1.05, such that an outer edge portion of the top disc 23 is flexed and shaped when the top disc 23 is pressed into opening of the tube 2 at the top end 11. Alternatively and as shown in this FIG. 2f, the top disc 23 is pre-formed, such that the outer edge portion already is flexed and shaped to a peripheral flange 24 projection out of a main plain of the top disc before being pressed into the opening of the tube 2 at the top end 11. As seen in FIG. 2g, the flange 24 extends in the longitudinal direction L across the dividing line 20, and has an attachment portion 32 positioned at the lid collar portion 18, which portion will form the lid collar 18 on the container lid 5. The flange 24 is aligned with the inner surface 7 of the container body 3 with the part of the top disc 23, including the flange 24, being located on the container body portion 3 side of the dividing line 20 forming a plug-in portion 15. The plug-in portion 15 having a side surface 16 extending in the longitudinal direction L and a main surface 17.

[0122] The peripheral flange 24 of the paperboard top disc 23 is attached to the inner surface of the lid collar portion 18 of the tube 2 at the attachment portion 32 of the peripheral flange 24. The attachment portion 32 of the peripheral flange 24 is the portion of the peripheral flange 24 facing the portion of the tube 2 above the dividing line 20, i.e. the lid collar portion 18 of the tube 2.

[0123] The attachment of the peripheral flange 24 may be performed prior or simultaneously to forming the locking arrangement. However, it could also be performed after forming the locking arrangement, as long as it is made prior or simultaneously to a step of arranging the slit 20.

[0124] FIG. 2h illustrates the step in which a locking arrangement is provided at the container body portion. The locking arrangement comprises a first locking element 21 provided at the inner surface of the container body portion 3 and a second locking element 22 provided at the side surface 16 of the plug-in portion 15, and is provided to the container body portion 3 and to the plug-in portion 15 by physically deforming the paperboard material 2 in the container body portion 3 and in the plug-in portion 15 by embossing a part of the container body portion 3 and the plug-in portion 15 between a male shaping tool 25 and an anvil 26 having a corresponding recess and thereby forming mating male and female locking elements 21,22. The male shaping tool 25 may be in the form of a pressing foot comprising an expandable portion pressing towards the peripheral flange 24, but the male shaping tool 25 and the anvil 26 may be any types of metal dies, the male shaping tool 25 having a raised surface and the anvil 26 having a mating surface recessed into it, wherein the two dies fit into each other. The container body portion 3 and the plug-in portion 15 are applied between the male shaping tool 25 and the anvil 25 and then heat and pressure are applied to squeeze the raised portion on the male shaping tool 25 into the recessed portion of the anvil 26.

[0125] FIG. 2i illustrates that a top end edge 9 of the tube 2 has been folded or rolled inwards over the peripheral flange 24. This folding or rolling inwards of the top end edge 9 over the peripheral flange 24 is an optional step which may be made at any point after attachment of the peripheral flange 24 of the top disc 23 to the inner surface of the lid collar portion 18.

[0126] FIG. 2j shows packaging container 1 provided with a slit 20 or weakening means 20 extending along 75-95% of the dividing line. The slit 20 or weakening means 20 may be arranged along the dividing line 20 before or after forming the tube 2. The remaining part of the periphery not comprising the slit 20 or the weakening means 20 provided between the container lid 5 formed and the container body 3, provides the packaging container 1 with a hinge 27. The hinge 27 may be provided with a hinge crease line extending along the imaginary dividing line 20. The hinge 27 is arranged between the container body 3 and the container lid 5 at one of the side walls of the packaging container 1.

[0127] The provision of the slit 20 or weakening means 20 allows allowing opening of the container top 5 comprising the container lid top member 18 and the lid plug-in portion 15, fixedly connected to the lid top member 18 at the attachment portion 32 by means of wither gluing or a weld seal. The container lid top member 18 and the container body 2 are provided with a top member abutment edge 19 and a container body abutment edge 8, respectively, by means of the slit 20 or by separating the lid top member 18 from the container body 3 at the weakening means 20 upon opening of the container top (5), as shown in FIG. 2k, showing the packaging container 1 with the container lid 5 in an open position.

[0128] However, the slit 20 or the weakening means 20 may also be provided along only 10-50% allowing only partial opening of the container lid 5 may normally only be partially opened. In such case the main surface 17 of the plug-in portion 15 may comprise a pivotable hinged lid portion and the side surface 16 of the plug-in portion 15 are provided with slits to allow separation of the pivotable hinged lid portion.

[0129] FIG. 3 shows a cross-sectional view of the packaging container 1 taken from lines III-III in FIG. 1b, wherein the cross section of the packaging container 1 has a modified rectangular shape. The opposing front and rear wall portions 36, 37 each has a convex shape, the corner portions are curved and the opposing side wall portions 38, 39 are straight. The transport closure 29 is applied in the packaging container with the transport closure peripheral flange 35 flexed towards the top end of the packaging container 1.

[0130] The transport closure 29 is furthermore provided with a tear line 41 and a pull-tab 33 for facilitated opening of the transport closure 29. A peripheral edge portion 40 surrounds a tear-open part 42, which is delimited from the peripheral edge portion 40 by the tear line 41. As illustrated in this figure, the front and rear wall portions 36,37 are wider than the side wall portions 36,37.

[0131] The transport closure may also be provided with cuts, forming a tear strip and a tear-away area which includes the tear strip. By pulling at the tear-strip formed in the top member, the connection or connections between the top member and the bottom member within the area constituted by the tear strip will cause the bottom member to break along the cuts in the top member. Thereby, both the top member and the bottom member within the tearable area can be removed from the container and to make the contents in the container available for use.