CONTAINER HAVING IMPROVED CURVED EDGE

Abstract

A container for consumer articles is at least partially formed from a cellulose-fiber based laminar blank having a thickness (T) and defining a portion of the container, which comprises at least a first planar wall and a second planar wall that are connected to one another by a curved edge portion. The curved edge portion has an inner surface and an outer surface, and the inner surface of the curved edge portion defines an ablation area (A), having a length (L) in the longitudinal direction of the curved edge portion and a width (W) that extends across the curved edge portion. The ablation area comprises two or more ablated lines extending substantially in the longitudinal direction of the curved edge portion. Each ablated line has a minimum residual thickness (RT) that is less than the thickness (T) of the laminar blank wherein the minimum residual thickness (RT) of each of the two or more ablated lines is at least about 30 percent and less than about 60 percent of the thickness (T) of the blank. The gap between the low points of two adjacent ablated lines is more than 0.2 millimetres and less than 1.6 millimetres.

Claims

1. A container for consumer articles, the container being at least partially formed from a cellulose-fiber-based laminar blank having a thickness (T), the laminar blank defining a portion of the container, which comprises at least a first planar wall and a second planar wall that are connected to one another by a curved edge portion; wherein the curved edge portion has an inner surface and an outer surface, and the inner surface of the curved edge portion defines an ablation area (A), the ablation area having a length (L) in the longitudinal direction of the curved edge portion and a width (W) that extends across the curved edge portion; wherein the ablation area comprises two or more ablated lines extending substantially in the longitudinal direction of the curved edge portion, each ablated line having a minimum residual thickness (RT) that is less than the thickness (T) of the laminar blank; wherein the minimum residual thickness (RT) of each of the two or more ablated lines is at least about 30 percent and less than about 60 percent of the thickness (T) of the blank; wherein the gap between the low points of two adjacent ablated lines is more than 0.2 millimetres and less than 1.6 millimetres; and wherein the thickness (T) of the laminar blank is from about 320 micrometres to about 360 micrometres.

2. (canceled)

3. A container according to claim 1, wherein the ablation area comprises five or more of said ablated lines over a substantial length at any longitudinal position of the curved edge portion.

4. A container according to claim 1, wherein the laminar blank has a basis weight of from about 160 grams per square metre to about 300 grams per square metre

5. A container according to claim 1, wherein each of the two or more ablated lines has an ablated width (X) of less than about 0.5 millimetres, as measured transversely to the longitudinal direction of the curved edge portion.

6. A container according to claim 5, wherein each of the two or more ablated lines has an ablated width (X) of from about 0.1 millimetres to about 0.5 millimetres, as measured transversely to the longitudinal direction of the curved edge portion.

7. A container according to claim 1, wherein the width (W) of the ablation area is from about 2 millimetres to about 8 millimetres.

8. A container according to claim 1, wherein the distance between adjacent ablated lines in the ablation area is less than about 1.2 millimetres.

9. A container according to claim 1, wherein the laminar blank has a stiffness in the bending direction of from about 50 milliNewtons to about 500 milliNewtons.

10. A container according to claim 1, wherein the laminar blank has a residual stiffness in the bending direction of from about 25 milliNewtons to about 100 milliNewtons.

11. A container according to claim 1, wherein the laminar blank has a surface roughness of from about 0.5 micrometres to about 1.5 micrometres.

12. A container according to claim 1, wherein the laminar blank has a surface strength of from about 1 metres per second to about 2 metre per second.

13. A container according to claim 1, wherein the ablation area comprises at least two ablated lines that extend in parallel over at least a part of the curved edge portion in its longitudinal direction.

14. A container according to claim 1, wherein the first planar wall is orthogonal to the second planar wall.

15. A container according to claim 1 comprising: a box portion comprising a box portion front wall, a box portion back wall, first and second box portion side walls, and a box portion bottom wall; and a lid portion depending along a hinge line from a top edge of the box portion, wherein the lid portion is moveable about the hinge line between an open position and a closed position.

16. A cellulose-fiber based laminar blank for forming a container for consumer articles, the blank having a thickness (T) and defining a portion of the container, which comprises at least a first planar wall and a second planar wall that are connected to one another by a curved edge portion; wherein the curved edge portion has an inner surface and an outer surface, and the inner surface of the curved edge portion defines an ablation area (A), the ablation area having a length (L) in the longitudinal direction of the curved edge portion and a width (W) that extends across the curved edge portion; wherein the ablation area comprises two or more ablated lines extending substantially in the longitudinal direction of the curved edge portion, each ablated line having a minimum residual thickness (RT) that is less than the thickness (T) of the laminar blank; wherein the minimum residual thickness (RT) of each of the two or more ablated lines is at least about 30 percent and less than about 60 percent of the thickness (T) of the blank; wherein the gap between the low points of two adjacent ablated lines is more than 0.2 millimetres and less than 1.6 millimetres; and, wherein the thickness (T) of the laminar blank is from about 320 micrometres to about 360 micrometres.

Description

[0074] The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

[0075] FIG. 1 depicts a perspective view of a container having at least one curved edge portion according to an embodiment of the present invention;

[0076] FIG. 2 is a photograph showing a magnified view of the cross section of a laminar blank according to a first embodiment of the present invention (Example 1);

[0077] FIG. 3 is a photograph showing a perspective view of the blank of FIG. 2 (Example 1);

[0078] FIG. 4 is a photograph showing a magnified view of the cross section of a laminar blank according to a second embodiment of the present invention (Example 2);

[0079] FIG. 5 is a photograph showing a perspective view of the blank of FIG. 4 (Example 2);

[0080] FIG. 6 is a photograph showing a magnified view of the cross section of a laminar blank according to the present invention (Example 3);

[0081] FIG. 7 is a photograph showing a perspective view of the blank of FIG. 6 Example 3);

[0082] FIG. 8 is a photograph showing a magnified view of the cross section of a laminar blank not according to the present invention (Comparative Example 1);

[0083] FIG. 9 is a photograph showing a perspective view of the blank of FIG. 8 (Comparative Example 1);

[0084] FIG. 10 is a photograph showing a magnified view of the cross section of a laminar blank not according to the present invention (Comparative Example 2);

[0085] FIG. 11 is a photograph showing a perspective view of the blank of FIG. 10 (Comparative Example 2);

[0086] As can be appreciated by the skilled person, FIG. 1 shows a container 100 for consumer goods, which can be formed by folding a cardboard or paperboard laminar blank having a thickness (T).

[0087] The container 100 is a substantially rectangular parallelepiped in shape and comprises a box portion 30 and a hinge lid 40 connected to the box portion 30 along a hinge line 50 extending across the back wall of the container 100. The overall size and construction of the box 30 and lid 40 of the container 100 is substantially the same as those of a standard hinge lid cigarette pack. The box portion 30 comprises a box front wall, a box back wall, a box bottom wall, a box left side wall and a box right side wall. The hinge lid 40 comprises a lid front wall, a lid back wall, a lid top wall, a lid left side wall and a lid left side wall. The hinge lid 40 is pivotable about the hinge line 50 between a closed position and an open position. In the closed position, the hinge lid 40 cover an access opening of the container 100 and the walls of the hinge lid 40 form extensions of the corresponding walls of the box portion 30. In the open position, the hinge lid 40 pivots about the hinge line 50 to project backwardly from the box portion 30 and the access opening at the top end of the box portion 30 be fully uncovered. The box portion 30 and the hinge lid 40 may be formed together from a single laminar blank having a thickness T. The container may be assembled from the laminar blank and filled using standard apparatus.

[0088] The container comprises a first planar wall 4, which in FIG. 1 is a side wall of the box portion 30. The container also comprises a second planar wall 8, which in FIG. 1 is the front wall of the box portion 30. The side wall 4 and the front wall 8 are connected to each other by a curved edge portion 20. Although not visible from the perspective view in FIG. 1, the inner surface of the curved edge portion 20 comprises a plurality of ablation lines that together define the curved edge portion 20, when the container 100 is assembled.

[0089] Five different laminar blanks were produced and folded to form a curved edge portion. Details of each laminar blank are provided below, and photographs of each laminar blank and their respective curved edge portions are shown in FIGS. 2 to 13. For all examples, the laminar blank was provided with a plurality of parallel ablation lines on its inner surface. The ablation lines were formed by applying a laser ablation tool to the inner surface of the laminar blank to remove material from said surface. This resulted in substantially V-shaped grooves being formed on the laminar blank's inner surface. The objective was to determine, which laminar blank or laminar blanks (when folded) would produce a curved edge portion having a smooth and gradual curvature that better approximates a theoretical curved profile. Testing and conditioning was conducted at 23 degrees Celsius and 50 percent relative humidity according to ISO 187, two weeks after the ablation lines had been formed.

EXAMPLE 1

[0090] FIG. 2 shows a magnified view of the cross section of a laminar blank according to a first embodiment of the present invention (Example 1). FIG. 3 shows a perspective view of the blank of FIG. 2 (Example 1).

[0091] The blank of Example 1 had a basis weight of 240 grams per square metre, a thickness (T) of 298 micrometres. Each ablated line was measured to have a minimum residual thickness of 33 percent of the thickness (T) of the blank, and an ablated width of 0.49 millimetres.

[0092] The gap is 0.7 millimetres and the residual stiffness in bending direction is 32 milliNewtons calculated based on the stiffness in cross direction before lamination. The stiffness of the laminar blank before ablation is 197 milliNewtons in machine direction and 98 milliNewtons in the cross direction (cross-direction is the direction of bending in this example).

[0093] As can be seen from FIGS. 2 and 3, the blank of Example 1 was found to exhibit a well-defined curved edge portion, having gradual curvature that better approximates a theoretical curved profile. The locations of the ablation lines could not be easily identified on the outer surface of the curved edge portion.

EXAMPLE 2

[0094] FIG. 4 shows a magnified view of the cross section of a laminar blank according to a second embodiment of the present invention (Example 2). FIG. 5 shows a perspective view of the blank of FIG. 4 (Example 2).

[0095] The blank of Example 2 had a basis weight of 270 grams per square metre, a thickness (T) of 340 micrometres. Each ablated line was measured to have a minimum residual thickness of 53 percent of the thickness (T) of the blank, and an ablated width of 0.26 millimetres.

[0096] The gap is 0.7 millimetres and the residual stiffness in bending direction is 76 milliNewtons calculated based on the stiffness in cross direction before lamination. The stiffness of the laminar blank before ablation is 290 milliNewtons in machine direction and 145 milliNewtons in the cross direction (cross-direction is the direction of bending in this example).

[0097] As can be seen from FIGS. 4 and 5, the blank of Example 2 was found to exhibit a well-defined curved edge portion, having gradual curvature that better approximates a theoretical curved profile. The locations of the ablation lines could not be easily identified on the outer surface of the curved edge portion.

EXAMPLE 3

[0098] FIG. 6 shows a magnified view of the cross section of a laminar blank according to a second embodiment of the present invention (Example 3). FIG. 7 shows a perspective view of the blank of FIG. 6 (Example 3).

[0099] The blank of Example 3 has a basis weight of 240 grams per square metre, a thickness (T) of 298 micrometres. Each ablated line is measured to have a minimum residual thickness of 58 percent of the thickness (T) of the blank, and an ablated width of 0.25 millimetres.

[0100] The gap is 0.7 millimetres and the residual stiffness in bending direction is 56 milliNewtons calculated based on the stiffness in cross direction before lamination. The stiffness of the laminar blank before ablation is 197 milliNewtons in machine direction and 98 milliNewtons in the cross direction (the cross direction the direction of bending in this example).

[0101] As can be seen from FIGS. 6 and 7, the blank of Example 3 was found to exhibit a well-defined curved edge portion, having gradual curvature that better approximates a theoretical curved profile. The locations of the ablation lines could not be easily identified on the outer surface of the curved edge portion.

COMPARATIVE EXAMPLE 1

[0102] FIG. 8 shows a magnified view of the cross section of a laminar blank not according to an embodiment of the present invention (Comparative Example 1). FIG. 9 shows a perspective view of the blank of FIG. 6 (Comparative Example 1).

[0103] The blank of Comparative Example 1 has a basis weight of 240 grams per square metre, a thickness (T) of 298 micrometres. Each ablated line is measured to have a minimum residual thickness of 59 percent of the thickness (T) of the blank, and an ablated width of 0.36 millimetres.

[0104] The gap is 2.1 millimetres. The stiffness of the laminar blank before ablation is 197 milliNewtons in machine direction and 98 milliNewtons in the cross direction (the cross direction the direction of bending in this example).

[0105] As can be seen from FIGS. 8 and 9, the blank of Comparative Example 1 was not found to exhibit a well-defined curved edge portion. That is, the curved edge portion did not have a gradual curvature that approximates a theoretical curved profile. Instead, the curved edge portion transitioned unevenly and randomly from the first planar panel to the second planar panel, with delamination along the curved edge portion being clearly visible.

COMPARATIVE EXAMPLE 2

[0106] FIG. 10 shows a magnified view of the cross section of a laminar blank not according to an embodiment of the present invention (Comparative Example 2). FIG. 11 shows a perspective view of the blank of FIG. 10 (Comparative Example 2).

[0107] The blank of Comparative Example 2 had a basis weight of 240 grams per square metre, a thickness (T) of 298 micrometres. Each ablated line was measured to have a minimum residual thickness of 66 percent of the thickness (T) of the blank, and an ablated width of 0.35 millimetres. The gap is 0.71 millimetres. The stiffness of the laminar blank before ablation is 197 milliNewtons in machine direction and 98 milliNewtons in the cross direction (the cross direction the direction of bending in this example).

[0108] As can be seen from FIGS. 10 and 11, the blank of Comparative Example 2 was not found to exhibit a well-defined curved edge portion. That is, the curved edge portion did not have a gradual curvature that approximates a theoretical curved profile. Instead, the curved edge portion transitioned unevenly and randomly from the first planar panel to the second planar panel, with delamination along the curved edge portion being clearly visible.

[0109] FIGS. 2 to 7 therefore indicate that, surprisingly, a cleaner looking, more well defined curved edge portion, having gradual curvature that better approximates a theoretical curved profile, can be produced when the ablation lines are applied to a laminar blank of the present invention.