A packaging article

Abstract

A packaging article (fig 1, 12) comprising a sheet of paperboard material. The paperboard material comprises a fluted layer 42, covered by opposing first and second facing layers 44 and 46. A portio

Description

FIELD

[0001] The present disclosure relates to a packaging article. In addition, the present disclosure relates to a blank forming packaging article and to a method of forming a blank. In particular, the present disclosure relates to packaging article formed from a corrugated paperboard material. BACKGROUND

[0002] Various demands are placed on packaging articles, such as boxes and trays, beyond a core function of protecting and enabling the transport of products held therein.

[0003] A particular demand is for such articles to make minimum use of raw materials for environmental reasons. A further demand is for such articles to be attractive at a point of sale, e.g. in a retail store, in order to enhance the sales of the product held therein. Additionally, it is desirable for such packaging articles to be manufactured without a requirement for a significant increase in capital expenditure on new production processes so that the above stated aims can be achieved on the same production lines as other products, production cost is minimised and production efficiency is maintained.

[0004] One way of visually differentiating a packaging article from a standard rectangular box or tray is to introduce curved forms at the corners of the article.

[0005] Standard three-layer corrugated board having a fluted centre layer surrounded above and below by upper and lower liner layers is not readily formed into a smooth curved shapes, particularly at tight radii, because the lining layers may buckle. Such localised buckling may result in a corner structure that is no longer a smooth curve but rather has one or more facets with relatively sharp corners therebetween. In addition, previous attempts to enable curves to be introduced to corrugated board have been limited to the forming of curves whose axes of curvature is aligned with the direction of the fluting.

[0006] US4286006 (BOELTER) discloses a corrugated material suitable for packaging applications in which a sheet of flexible material having high resistance to tearing and stretching is bonded to the flutes of a sheet of single faced corrugated board. This is said to result in a structure which is rollable in the direction of the flexible substrate. SUMMARY

[0007] The present disclosure seeks to overcome or at least mitigate the problems of the prior art.

[0008] A first aspect of the present disclosure provides a packaging article comprising a sheet of paperboard material comprising a fluted layer covered by opposing first and second facing layers; a portion of the sheet defining a curve region comprising a plurality of laterally spaced elongate rows of cuts extending at least through the full depth of the first facing layer and not extending through the second facing layer. The curve region may be curved with the first facing layer being concave about an axis generally aligned in a direction of the cuts, thereby generating a convex curved outer profile of the second facing layer.

[0009] Advantageously this enables the packaging article to have smooth curved regions, for example at intersections between adjacent panels corners between adjacent panels to be created in place of a sharp corner. Providing cuts on the concave (internal) face only maintains the visual appeal of the convex (external) face. Such regions may minimise the amount of corrugated board required to manufacture the article. Additionally, the curved shapes may differentiate the packaging article visually from standard articles, enhancing so called "shelf appeal". As the cuts are localised only to the curved regions, the strength of the remainder of the article is maintained.

[0010] At least one of the rows of cuts may comprise discrete first and second aligned cuts interrupted by an uncut bridge portion.

[0011] By leaving such bridge portions, adjacent strips of the first facing layer retain a connection to each other. This may be beneficial in avoiding parts of the first facing layer becoming separated from the fluted layer.

[0012] The discrete cuts may be longer than the bridge portion, for example at least three times longer.

[0013] Advantageously this arrangement ensures that there are sufficient lengths of cuts to facilitate the curving / bending of the curve region, but whilst providing a connection between adjacent parts of the first facing layer.

[0014] The bridge portions of at least two adjacent rows of cuts may be aligned. Optionally the bridge portions of all rows may be aligned.

[0015] This arrangement allows for a simplified set up of cutting blades to generate the rows of cuts.

[0016] The bridge portions of at least two adjacent rows of cuts may be staggered. Optionally the bridge portions all mutually adjacent rows of cuts may be staggered.

[0017] This arrangement of bridges may further minimise the risk of stresses generated by the bending of the curve portions from separating parts of the first facing layer from the rest of the paperboard material.

[0018] The curve region may comprise at least three rows of cuts. The rows of cuts may be evenly spaced.

[0019] Such an arrangement may help to generate a curve of constant radius when bent.

[0020] At least two rows of cuts may be parallel to each other. Optionally all the rows of cuts may be parallel to each other.

[0021] At least two rows may comprise straight parallel lines or the at least two rows may comprise parallel curves.

[0022] An arrangement of straight parallel lines may assist in producing a curve that forms an arc of a cylinder, whereas an arrangement comprising parallel curves may generate bulges or depressions in the curve, to add further visual interest to the packaging article.

[0023] The rows may terminate with a further uncut bridge portion at an edge of the sheet, for example a bridge of 2mm or more in length.

[0024] This arrangement of bridges may further minimise the risk of stresses generated by the bending of the curve portions from separating parts of the first facing layer from the rest of the paperboard material.

[0025] A lateral spacing between adjacent rows of cuts may be between 1mm and 10mm, optionally between 2mm and 7mm.

[0026] The curve region may comprise at least eight, optionally at least ten, rows of cuts for every 90° of curvature.

[0027] This number of cuts ensures that paperboard material is not overly stressed when bent by this amount, and the exterior face looks visually smooth.

[0028] The at least two rows of cuts may be parallel to each other and may be in substantially parallel alignment with an axis of flutes of the fluted layer.

[0029] This may assist in the generation of a smooth curve to the curve region.

[0030] The fluted layer may have a spacing between adjacent flutes. The spacing between the at least two rows of cuts may less than or equal to the spacing between the adjacent flutes.

[0031] Advantageously this may further minimise the risk of stresses generated by the bending of the curve portions from separating parts of the first facing layer from the rest of the paperboard material.

[0032] At least one row of cuts may be in non-parallel alignment with an axis of flutes of the fluted layer. For example the row of cuts may be at substantially 45° or substantially 90° to the axis of the fluted layer.

[0033] This provides greater design freedom to the packaging article by allowing curves to be created when non-parallel to the flute axis.

[0034] The curved region may comprise at least two rows of cuts arranged to be mutually convergent.

[0035] This arrangement of rows of cuts may facilitate curves that are of non-constant cross-section.

[0036] The curve of the curve region may be an arc of a truncated cone.

[0037] This shape may be beneficial for packaging articles such as trays which have tapering side panels and in which adjacent panels are beneficially connected by such truncated cone arcs.

[0038] The curve region may be a first curve region and the article may further comprise a second curve region. Optionally, the package may comprise four curved regions providing smooth curves at four corners of a cuboid packaging article.

[0039] The second curve region may comprise rows of cuts extending in a different direction to the first curve region.

[0040] This arrangement of cuts allows curves to be created in multiple orientations and at non-zero angles with respect to an axis of flutes of the fluted layer.

[0041] At least two rows of cuts may follow a wave-shaped path.

[0042] This arrangement may further enhance the bonding of the first facing layer to the fluted layer.

[0043] The at least two rows of cuts may follow a zig-zag path.

[0044] This arrangement may further enhance the bonding of the first facing layer to the fluted layer.

[0045] An amplitude of the wave-shape or zig-zag shape may be substantially half of a spacing between the at least two rows of cuts.

[0046] This arrangement may further enhance the bonding of the first facing layer to the fluted layer, whilst reducing a tendency of the shapes to cause bulging of the curve region.

[0047] A spacing between the at least two rows of cuts may be the same or greater than a spacing between a peak-to-peak pitch of the fluted layer.

[0048] This arrangement may further enhance the bonding of the first facing layer to the fluted layer.

[0049] The paperboard material may comprise a second fluted layer bonded to the first facing layer, and a third facing layer intermediate the first fluted layer and the second fluted layer and bonded to the first fluted layer and the second fluted layer. Optionally the rows of cuts may additionally extend through the third facing layer.

[0050] This depth of cut enables smooth curves to be created in packaging articles manufactured from double wall corrugated board.

[0051] The packaging article may be a cuboid box or a tray comprising a base and side walls.

[0052] The curve region may be adjoined by first and second substantially planar panels, for example a side panel and an end panel.

[0053] Advantageously, by only applying cuts to the curve region, the rigidity of the adjoining panels is maintained. This may be beneficial for the structural strength of the packaging article, by allowing multiple articles to be stacked on each other without relying on the contents of the article for the crush strength. In addition, this may aid erection of the article, as the curve portions tend to preferentially bend over the planar panel, which desirably stay substantially planar.

[0054] A second aspect of the present disclosure provides a blank for forming a packaging article comprising a sheet of paperboard material comprising a fluted layer covered by opposing first and second facing layers; a portion of the sheet defining a curve region comprising a plurality of laterally spaced elongate rows of cuts extending at least through the full depth of the first facing layer and not extending through the second facing layer; wherein the curve region is configured to be curved with the first facing layer being concave about an axis generally aligned in a direction of the cuts, to thereby generate a convex curved outer profile of the second facing layer.

[0055] At least one of the rows of cuts may comprise discrete first and second aligned cuts interrupted by an uncut bridge portion.

[0056] By leaving such bridge portions, adjacent strips of the first facing layer retain a connection to each other. This may be beneficial in avoiding parts of the first facing layer becoming separated from the fluted layer.

[0057] A lateral spacing between adjacent rows of cuts may be between 1mm and 10mm, optionally between 2mm and 7mm.

[0058] Further optional features of the second aspect may be provided by and correspond to optional features of the first aspect as recited above.

[0059] A third aspect of the present disclosure provides a method of manufacturing a blank of the second aspect, comprising the step of cutting a plurality of laterally spaced elongate rows of cuts through least the full depth of the first facing layer and not through the second facing layer to form a curve region.

[0060] The method may comprise a further step of bending the curve region with the first facing layer being concave about an axis generally aligned in a direction of the cuts. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Embodiments will now be described, by way of example only, with reference to the accompanying figures, in which:

[0062] Figure 1 is a plan view of a blank according to an embodiment of the disclosure;

[0063] Figure 2 is an isometric view of a portion of the blank of Figure 1 encircled by area A;

[0064] Figure 3 is a perspective view of a packaging article according to an embodiment of the present disclosure formed from the blank of Figure 1;

[0065] Figure 4 is a cross-sectional view of the material forming the blank of Figure 1;

[0066] Figure 5 is a simplified illustration of apparatus and method for forming a blank of the present disclosure;

[0067] Figure 6 is a plan view of a blank according to another embodiment of the present disclosure;

[0068] Figure 7 is a plan view of a further blank according to another embodiment of the present disclosure;

[0069] Figure 8 is a perspective view of a portion of the blank of Figure 7;

[0070] Figures 9A to 9C are plan views of alternative formats of cuts for forming a curve region of a blank according to embodiments of the present disclosure;

[0071] Figure 10 is a plan view of a still further format of cuts for forming a curve region of the blank according to another embodiment of the present disclosure;

[0072] Figure 11A is a perspective view of a simplified blank of a packaging article formed from a different substrate;

[0073] Figure 11B is a simplified cross-sectional view of an apparatus for manufacturing the blank illustrated in Figure 11A when flat;

[0074] Figure 12A is a perspective view of a simplified blank of a packaging article formed from a different substrate;

[0075] Figures 12B, 12C, and 12D illustrate the process of forming the rows of cuts in the blank of Figure 12A when flat;

[0076] Figures 13 to 15 are perspective views of further simplified blanks according to further embodiments of the present disclosure;

[0077] Figure 16 is a plan view of a further format of a rows of cuts in a curve region according to another embodiment of the present disclosure;

[0078] Figure 17 is a plan view of a panel having a further format of rows of cuts in a curve region according an embodiment of the present disclosure;

[0079] Figure 18 is a perspective view of the panel of Figure 19 bent to form a curve;

[0080] Figure 19 is a plan view of a blank according to another embodiment of the present disclosure;

[0081] Figure 20 is a perspective view of a packaging article erected from the blank of Figure 19;

[0082] Figure 21 is a perspective view of a further blank according to an embodiment of the present disclosure;

[0083] Figure 22 is a perspective view of the blank of Figure 21 erected to form part of a packaging article;

[0084] Figure 23 is a plan view of a further format of cuts for forming a curve region of a blank according to a further embodiment of the present disclosure;

[0085] Figure 24 is a perspective view of a portion of a part erected blank incorporating the format of cuts of Figure 23;

[0086] Figure 25 is a further perspective view of the part-erected blank of Figure 24;

[0087] Figure 26 is a perspective view of a packaging article erected from the blank of Figures 24 and 25;

[0088] Figure 27 is a perspective view of part of a further blank according to an embodiment of the present disclosure

[0089] Figure 28 is a portion of the blank of Figure 27 when partially erected; and

[0090] Figure 29 is a packaging article erected from the blank of Figure 27. DETAILED DESCRIPTION OF EMBODIMENTS

[0091] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of various embodiments and the disclosure. Those skilled in the art will understand that: the present teachings may be practiced without these specific details or with known equivalents of these specific details; that the present disclosures are not limited to the described embodiments; and, that the present disclosures may be carried out in a variety of alternative embodiments. It will also be appreciated that well known methods, procedures, apparatus, and systems may not have been described in detail for the sake of brevity.

[0092] Figure 1 shows a blank 10 according to an embodiment of the present disclosure. As will be described in more detail below, the blank 10 is for forming a packaging article 12 according to a further embodiment of the present disclosure, as illustrated in Figure 3.

[0093] The blank 10 comprises, in series from left to right, a top panel 14, first a side panel 16, a base panel 18, a second side panel 20 and a glue flap 22. The panels 14 to 22 are hingedly connected by fold lines 24a-d, denoted by broken lines.

[0094] The top panel 14 and base panel 18 are provided with respective end flaps 26a, 26b, 28a and 28b. At their lateral edges, the end flaps 26a, b and 28a, b, are connected to their respective base and top panels 14 and 18 by fold lines 24e-h.

[0095] In this embodiment, the first and second side panels 16 and 20 are connected to corresponding end flaps 30a, 30b, 32a and 32b via corresponding curve regions 34a, 34b, 36a and 36b which are described in more detail below.

[0096] Each of the top 14, first and second side panels 16, 20 and base panel 18 are generally rectilinear, except that the top panel 14 and base panel 18 have rounded corners 38a-d and 40a-d respectively.

[0097] Figure 2 shows an enlarged portion of the blank of Figure 1 as bounded by region A of Figure 1.

[0098] From Figure 2 it can be seen that the blank is formed from double faced corrugated board. Specifically, the corrugated board forming the blank comprises a fluted layer 42 covered by and bonded to opposing first and second facing layers 44 and 46. For example, the corrugated board is formed from fibrous cellulosic based material, such as paperboard or cardboard. The fluted layer 42 has a wave shape which defines voids between the first and second facing or liner layers 44 and 46. The fluted layer 42 of the corrugated board may be B, E, R, or micro-type flute material. However, in other embodiments other grades of fluted layer 42 may be suitable. The corrugated board may be manufactured from standard paperboard materials using a standard corrugator machine. For example, both facing layers 44 and 46 may be made of the same grammage and quality of material. In other examples the second (outer) layer 46 may be made of higher quality, higher cost material to enable a better finish and / or be more able to take print. Thus for reasons of economy the second layer may be thinner, and the overall strength of the maintained by raising the thickness of the first facing layer 44. As depicted, the first facing layer 44 is uppermost and is intended to form the interior face of the packaging article 12 when erected.

[0099] In this embodiment, the curve region 34b comprises a plurality of elongate rows of cuts 48 which are spaced apart from each other and do not intersect along their length.

[0100] In this embodiment, the curve region 34b is made up of 12 rows of cuts 48, but for brevity, two rows of cuts denoted 48a and 48b are described in more detail. In other embodiments the number of rows may be increased or decreased depending upon the requirements of the curve region in terms of radius of curvature, angle through which the region is to be bent etc.

[0101] Referring to Figure 4, the first and second rows of cuts 48a and 48b extend to a minimum depth through the entire thickness of the first facing layer 44. The rows of cuts 48a, 48b may additionally extend through the fluted layer 42. For example, the cut lines may extend through up to 75% of thickness X of the fluted layer 42, e.g. up to 50% or up to 25%. Depending upon the position of the cut with respect to the peaks of the fluted layer 42, the fluted layer may or may not be severed at that location. However the rows of cuts do not extend through the second facing layer 46 at all.

[0102] The first row of cuts 48a extends parallel to the axis of the fluted later 42. The cut of the first row 48a is not continuous. That is, the row 48a comprises a plurality of discrete cuts 48a', 48a" etc. separated by uncut portions or bridges 50 of the first facing layer 50. The discrete cuts 48a', 48a" are straight and coaxial in this embodiment. The discrete cuts 48a', 48a" are longer than the bridges 50. In this embodiment the discrete cuts 48', 48" are approximately 15 times longer than the bridges 50 (30mm cut and 2mm bridge). In other embodiments, the cuts 48a' 48a" may typically be at least three times longer than the bridges 50, but it will be appreciated that the ratios can be altered to achieve a particular desired effect, which ensure production is reliable and throughputs can be maximised.

[0103] Additionally, the discrete cut 48a' stops before reaching a free edge of the curve region 36 - i.e. a further bridge 52 of uncut first facing layer 44 is located adjacent the edge. In this embodiment the further bridge 52 is longer than the bridges 50, for example 5mm. However, in other embodiments may be the same length or shorter than the bridges 52, or may be omitted altogether.

[0104] The presence of the bridges 50, 52 alone or in combination may reduce the risk of strips of the first facing layer 44 between the rows of cuts 48 becoming separated from the fluted layer 42.

[0105] The second row of cuts 48b is spaced from the first row and parallel thereto. The spacing between the adjacent rows is less than or equal to the pitch (peak-to-peak) of the flutes in the fluted layer 42, which has been found to assist in retaining the first facing layer 44 on the fluted layer 42. The pitch of the flutes in this embodiment is 4mm and a 4mm spacing is also used between the rows 48a and 48b.

[0106] The second row 48b has a similar format of cuts 48b', 48b" and bridges 50, 52 as the first row, except that the bridges 50 are offset (staggered) from the bridges 50 of the first row 48a. This is achieved by the first cut 48b' being half the length of the second cut 48b". This arrangement may further enhance the adhesion of the first facing layer 44 to the fluted layer by distributing stresses in the first facing layer 44, as well as achieving a smoother profile to the convex face of the curve portion when bent.

[0107] As is apparent from Figure 2 the remaining rows of cuts 48 repeat the cut patterns of the first and second rows 48a, 48b to continue the staggered pattern and so are not described in more detail.

[0108] The curve regions 34a, 36a, and 36b have a similar format to the curve region 34b in this embodiment.

[0109] Figure 3 shows the erected packaging article 12 formed from the blank 10. In this embodiment the packaging article 12 is a box which is erected by folding the top panel 14, first side panel 16, base panel 18, second side panel 20 and glue flap 22 through 90° about respective fold lines 24a-d and securing the glue flap 22 to the top panel 14 to form a rectangular tube.

[0110] The end flaps 30a, 30b, 32a, 32b are then folded inwardly to be brought into alignment top and bottom with the fold lines 24e, 24f, 24g and 24h. This folding causes the curve regions 34a, 34b, 34c, 34d to adopt a smooth arc profile that transitions 90° between the first and second panels 16, 18 and the respective end flaps 30a, 30b and 32a, 32b. In this embodiment the arc is substantially a circular 90° arc. This contrasts to the usual sharp angular crease at corners of such boxes.

[0111] The end flaps 26a, 26b and 28a, 28b are then folded inwardly about the fold lines 24e, 24f, 24g and 24h and secured to the end flaps 30a, 30b, 32a, 32b by adhesive or the like to produce the fully erected packaging article 12.

[0112] From Figure 3 it can be seen that the rounded corners 38a-d and 40a-d of the top and base panels are substantially matched by the corresponding curve regions 34a, b and 36a, b.

[0113] Whilst the rows of cuts 48 are visible in Figure 3, it will be appreciated that this is to illustrate their internal position at the curve regions 34a, 34b, 34c, 34d. In reality an observer would only see the smooth arcuate profile from the outside of the packaging article 12 as the corrugated board material is opaque and the rows of cuts 48 are internal.

[0114] It has been found that the rows of cuts 48 of the present disclosure promote a smooth arc to be consistently created during erection of packaging articles, including by automated processes, without unwanted buckling or creases being formed. Without being committed to a particular mode, the rows of cuts 48 are believed to achieve this effect by allowing the first facing layer more freedom to flex and / or slide over adjoining portions separated by the cuts, without buckling or crumpling occurring. This enables smaller radii of the curves to be reliably achieved, e.g. a radius of 30mm which can match a radius of a typical 330ml bottle, 33mm which can match a 330ml drinks can, or 35mm which can match a typical 750ml bottle of wine or spirits.

[0115] Accordingly, the curve regions 34a, 34b, 34c, 34d may be employed to save materials in packaging articles 12 holding several such cans or bottles by proving such rounded corners to match the shape of such cans or bottles. Additionally, since the rows of cuts can be localised to only those areas requiring the curve, the strength of the corrugated board forming the remainder of the packaging article 12 is not reduced. Further, the use of the curve regions may improve the aesthetics of the packaging article, adding to so called "shelf appeal" compared to standard cuboid boxes, potentially leading to increased sales of the products within.

[0116] Referring to Figure 5, the blank 10 of the present disclosure is manufactured using a flatbed die cut process which is standard except for the provision of additional cutting blades 54 to a support 56 of a die 55 to form the rows of cuts 48, to the depth described above, where required. The same die 58 may additionally perform through cuts to cut an outline of the blank 10, creases to form the fold lines 24a-g- and / or perforations as required. In other embodiments, the blank 10 may be manufactured in a rotary die cutting process or any other suitable method.

[0117] Figure 6 illustrates a blank 110 according to another embodiment of the present disclosure. Like parts are labelled by like numerals with the addition of the prefix '1' and only differences are described in more detail below. The blank 110 has the same layout as the blank 10 except in relation to the curve regions 134 and 136. In this embodiment each of the curve regions 134a-d is formed from rows of cuts 148, where each row is formed of a single continuous cut 148a, 148b with no bridges, extending from edge-to-edge. This arrangement may simplify production of the dies but may require closer matching of the pitch between adjacent cut lines and the pitch of the fluted layer (not visible), if the two are parallel, to minimise the risk of separation of the first facing layer from the fluted layer.

[0118] Figures 7 and 8 illustrates a blank 210 according to another embodiment of the present disclosure. Like parts are labelled by like numerals with the addition of the prefix '2' and only differences are described in more detail below. Subsequent embodiments are numbered with prefixes '3', '4', '5' etc. and are similarly described in this way.

[0119] The blank 210 has the same layout as the blanks 10 and 110 except in relation to the curve regions 234 and 236. With reference to Figure 8 in particular, the rows of cuts 248 comprise the same bridges 252 adjacent each edge of the curve region 234b as the blank 10. However, the bridges 250 between the discrete cuts 248b' and 248b" are aligned with the bridges 250 between discrete cuts 248a' and 248a". This pattern is repeated throughout the region 234b and the other regions 234a, 236a and 236b. This results in all of the discrete cuts being the same length and there being no staggering.

[0120] Figures 9A, 9B, and 9C illustrate further curve regions 334, 434 and 534 which may be utilised on blanks 10, 110, 210 or other blanks to form packaging articles.

[0121] In Figure 9A a first row of cuts 348a has three discrete cuts 348a, 348a" and 348a'" of equal length separated by two bridges 350 of uncut material. A second row of cuts 348b has two discrete cuts 348b' and 348b" separated by one bridge 350. This arrangement is alternated across the curve region 334, thus creating a staggered pattern. The bridges 350 have the same length. The spacing between adjacent rows 348 is relatively wide.

[0122] In the curve region 434 of Figure 9B the lengths of discrete cuts and bridges in the rows of cuts 448a and 448b is the same as in Figure 9A and repeats across the region in the same way. However the spacing between the adjacent rows is significantly smaller than in Figure 9A. This closer arrangement of cuts may allow a smaller radius of curvature to be achieved with a smooth exterior surface.

[0123] In Figure 9C the arrangement of rows of cuts 548a and 548b is similar to 348a and 348b of Figure 9A, except that the bridges 550a of the row of cuts 548a have a greater width Y than the bridge 550b of row 548b, which has a smaller dimension Z. This arrangement may create a subtly different pattern to the external face of a curve formed from this curve region compared to Figure 9A, and / or may be used to optimise production yield and throughput. In addition, if the bridge size is increased, the rule length (length of cutting blades 54) is reduced, and the pressure required to die cut is reduced. Further, reducing the rule length may also improve the overall strength of the support 56 of the die 55.

[0124] Figure 10 shows a curve region 634 in which the rows of cuts are arranged in three sub regions 634a, 634b and 634c with differing patterns of cut. Specifically, the central subregion 634b has the same arrangement of rows of cuts as the region 434 of Figure 9B and this is bounded laterally by outer regions 634a and 634c which follow the same pattern of rows of cuts as Figure 9C. The specific details of the cuts are therefore as set out above in each region. This curve region may as a result naturally result in sectors thereof having differing radii of curvature when bent around. Specifically the sub-region 634b in the middle may naturally form a smaller radius of curvature than the outer regions 634a, 634c.

[0125] Figures 11A and 11B show the application of the curve region of the present disclosure to a double wall corrugated board blank and packaging article. In Figure 11 a simplified blank is 710 shown comprising a curve region 734 and an adjacent panel 730. The corrugated board of the blank comprises a first facing layer 744 and a second facing layer 746 enclosing first and second fluted layers 742 and 758. the first facing layer is bonded to the second fluted layer and the second facing layer is bonded to the first fluted layer. An intermediate third facing layer 760 separates and is bonded to the two fluted layers 742 and 758.. The second fluted layer 758 is arranged with peaks and troughs extending parallel to those of the first fluted layer 742. In this embodiment, the peak-to-peak pitch of the second fluted layer is smaller than that of the first fluted layer 742, and the thickness of the second fluted layer is also less than the first fluted layer. This may be beneficial to reduce setup time when switching between different production runs - e.g. switching from BC-flute to BE-flute enables the B roll to be left in situ. In other embodiments this is not necessarily the case, however.

[0126] In particular, it may be desirable to reverse the arrangement above to provide the finer flute on the outside to achieve a smoother exterior surface. An embodiment with this arrangement is shown in Figures 12A- 12D, in which it can be seen that the second flute layer 858 is thicker and has a larger pitch than the first flute layer 842.

[0127] Figure 12B shows an initial stage of the die-cutting process where the blades 854 of the die are clear of the blank 810. In Figure 12C the die has been lowered so that the blades are cutting the first facing layer 844, and also into the second fluted layer 858 where the blades intercept the peaks thereof. In some embodiments the die-cutting may only occur to this depth, in particular if a higher pressure is not achievable due to, for example, the physical characteristics of the corrugated board. This has been found to enable curves to be introduced into the curve region 834, but the appearance may not be optimum and / or a larger radius of curvature is required.

[0128] Figure 12D illustrates the blades 854 cutting deeper into the blank. In this Figure the blades 844 have cut through the entire depth of the second fluted layer 858 and the entire third facing layer 860. The blades 854 have also cut partially into the first fluted layer, although as depicted have not intercepted and cut into flutes. Cutting to this depth enables the best appearance and / or bends with a smaller radius of curvature to be achieved.

[0129] In addition, two layers of identical flute may also be used, such as EE-flute.

[0130] As can be seen in Figure 11, the curve portion 734 has a similar pattern of rows of cuts as depicted in Figure 9A, but in the embodiment the die 755 is arranged to cut through at least the third facing layer 760, second fluted layer 758 and the first facing layer 744. The blades 754 of the die 755 do not, however cut through the second facing layer. In some embodiments, the blades 754 may cut through the first fluted layer 742. In this embodiment the axes of the cuts are parallel to the axes of the fluted layers 742, 758.

[0131] Figures 13 and 14 show simplified blanks 910 and 1010 according to further embodiments of the present disclosure and similar to the blank 710 of Figure 11 with a similar pattern of rows of cuts 948 and 1048 in the respective curve regions 934 and 1034. The cuts are to the same depth as the preceding embodiments. The blank 910 is formed from double faced single fluted corrugated board as depicted in Figure 4 and the blank 1010 is formed from double wall double fluted corrugated board as depicted in Figure 11B.

[0132] As in the preceding embodiments a bend is introduced into the curve regions 934 and 1034 whose centre of curvature extends parallel to the cuts forming the curve regions. In contrast to the preceding embodiments the flutes extend at 90° to the direction of the cuts. Ordinarily bending the corrugated board in a direction normal to the flutes is more likely to result in buckling / creasing rather than a smooth arc to the board. However the present inventors have found that providing curve regions with cuts as described above enables smooth bends to be formed in this direction.

[0133] Figure 15 shows a simplified blank 1110 according to a further embodiment of the present disclosure and which is similar to the blank 710 of Figure 11 with a similar pattern of cuts in the curve region 1134. The cuts are to the same depth as the preceding embodiments. The blank 1110 is formed from double faced single fluted corrugated board as depicted in Figure 4. In this embodiment the flutes extend at an acute angle to the rows of cuts 1148, for example at an angle of 45° to the cuts. Similarly, the present inventors have found that providing curve regions 1134 with cuts as described above enables smooth bends to be formed in this direction.

[0134] Where the rows of cuts 1148 are arranged at a non-zero angle to the flutes, there may be a reduced need for bridges, as the strips of first facing layer between the cuts may be more reliably bonded to the fluted layer, and so need less connection to adjacent strips to hold them in place.

[0135] Figure 16 illustrates a simplified blank 1210 comprising a curve region 1234 of non-parallel rows of cuts 1248. Specifically, the rows of cuts in this embodiment radiate from a point C (but do not extend as far as the point and so do not meet), and are equiangularly spaced from each other. The rows of cuts 1248 comprise staggered bridges 1250 between discrete cuts. The cuts extend to the same depth as the previous embodiments. Inherently, each of the rows of cuts 1248 intersects the axes of the flutes at a different angle.

[0136] Rows of cuts 1248 made in this way promote the forming curves in a blank, which are an arc of a cone or truncated cone. As in the preceding embodiments, the first facing layer comprising the cuts forms the concave face, and the second facing layer forms the convex face.

[0137] Figure 17 shows a simplified blank 1310 according to another embodiment of the present disclosure. The curve region 1334 of the blank 1310 has a similar format of bridges 1350 and cuts to the curve regions 34a, 34, 36a, 36b of the first embodiment, except the rows of cuts 1248 have a wave shape, whilst remaining parallel and equidistant to each other. When folded inwardly as shown in Figure 18 this results in a bulge 1362 forming in part of the curve region indicated in Figure 18. Such a bulge 1362 may provide further visual interest to the curve shape.

[0138] Figure 19 shows another embodiment of a blank 1410 for forming a packaging article 1412 in the form of a tray, as shown in Figure 20. The blank comprises a base panel 1418, a first side panel 1316, second side panel 1420, a first end panel 1426 and a second end panel 1428. The side and end panels 1416, 1420, 1426 and 1428 are generally trapezoidal, being wider away from the base panel 1418. The base panel 1418 is rectangular with rounded corners. The side and end panels 1416, 1420, 1426 and 1428 are hingedly connected to the base panel 1418 by fold lines 1424a-d. End flaps 1430a, 1430b, 1432a, 1432b are connected to the first and second side walls 1416 and 1420 respectively by curve regions 1434a, 1434b, 1436a and 1436b.

[0139] The curve regions 1434a, 1434b, 1436a and 1436b are provided with rows of cuts 1448 that are non-parallel, equiangularly spaced and mutually converge in the direction of the base panel 1418.

[0140] The blank 1410 is erected to form the packaging article 1412 by folding the first and second side panels 1416 and 1420 upwardly and inwardly, and folding the end flaps 1430a, 1430b, 1432a, 1432b inwardly so as to be generally in alignment with the fold lines 1424c and 1424d. The end panels 1426 and 1428 are then folded upwardly and inwardly and are secured to the end flaps 1430a, 1430b, 1432a, 1432b.

[0141] Due to the shape of the side and end panels 1416, 1420, 1426 and 1428 the packaging article 1412 has a tapered shape that enables multiple packaging articles to nest within each other. The convergent arrangement of the rows of cuts 1448 allows rounded corners to be formed which also taper to match the adjoining panels.

[0142] Figure 21 shows a simplified blank comprising a rectangular base panel 1518 and four curve regions 1534a-d, one at each edge of the base panel. The rows of cuts 1548 are configured in a similar way to the curve region 334 of Figure 9A. The flutes of the blank extend parallel to the cuts of the curve regions 1534b and 1534d, and at 90° to the direction of the rows of cuts in the curve regions 1534a and 1534c.

[0143] From Figure 22, which shows a partially erected packaging article 1512 formed from the blank 1510, it can be appreciated that despite the differing orientations of the rows of cuts with respect to the direction of the flutes each of the curve regions is able to bent around to form a smooth and even curved profile. In this embodiment it can also be seen that the curve regions are bent through 180°, rather than 90° as in the previous embodiments.

[0144] Figure 23 shows a further format of cuts to form a curve region 1634. In this embodiment, the cuts are a wave shape and bridge layout similar to the embodiment of Figures 17 and 18 and are cut to the same depth as described with respect to Figure 4.

[0145] In Figure 23 the rows of cuts 1648 are shown superimposed on lines indicating the position of peaks 1664 of the fluted layer 1642 (Figure 24). It can be seen that the pitch of the rows of cuts 1648 is slightly more than the pitch of the peaks 1664 of the fluted layer 1642, and that the waves of the rows of cuts curve so the peak of one row of cuts is aligned with a trough of the adjacent row of cuts 1648. As a result, each row of cuts 1648 crosses a peak of the fluted layer, meaning that the strips of the first facing layer 1644 between each row of cuts are bonded to at least two peaks 1664. This has been found to further enhance the retention of the first facing layer 1644 on the fluted layer 1642.

[0146] In this embodiment, the fluted layer 1642 is E-flute having a pitch of approx. 3mm, the pitch between the rows of cuts 1648 is 4mm and the amplitude of the waves is 2mm. The present inventors have found that having an amplitude that is approximately half the spacing between rows of cuts 1648 minimises the bulging effect described in relation to the embodiment of Figures 17 and 18. An increase in amplitude to 3mm creates more visible bulges, however. For thicker fluted layers (such as B- or C-flute) having a greater flute pitch, a proportionately larger spacing between rows of cuts and larger amplitude may be beneficial.

[0147] Figures 24, 25 and 26 show the curve region of Figure 23 incorporated into a blank 1610 having the same layout of panels as the blank 10 of the first embodiment and therefore not described in more detail, but formed with curve regions 1634a, 1634b, 1636a, 1636b having the format of cuts 1634 shown in Figure 23.

[0148] Figures 27 and 28 show curve regions 1734b and 1736b of a blank 1710 having the same layout of panels as the blank 10 of the first embodiment. In this embodiment, the rows of cuts 1748 employ a similar principle to the wave-shaped cuts of Figures 23 to 26, but wherein the cuts form a regular zig-zag (geometrically a regular planar skew apeirogon) pattern.

[0149] In this embodiment, the spacing between adjacent rows 1748 is also 4mm and the amplitude is 2mm. The peak-to-peak pitch of the fluted layer 1742 is 3mm. This results in each row of cut 1748 crossing a peak of the fluted layer, and the strips of first facing layer 1744 crossing and being bonded to at least one peak. This has been found to enhance the retention of the first facing layer 1744 on the fluted layer 1742. For thicker fluted layers having a greater pitch a proportionately larger spacing between rows of cuts and larger amplitude may be beneficial.

[0150] In this embodiment the bridge portions 1750 are provided at each vertex and each discrete cut 1748a' and 1748a" forms a complete side between each vertex. This may further improve the retention of the first facing layer 1744 to the fluted layer 1742, although in other embodiments, this need not be the case.

[0151] The internal angle between adjacent discrete cut sides 1748a' and 1748a" is relatively large at approximately 160° in this embodiment, but may be adjusted as required, e.g. depending on the overall dimensions of the curve region.

[0152] Figure 29 shows the blank 1710 fully erected to form a packaging article 1712 similar to that of Figure 3, and being erected in the same way. As for Figure 3, an observer would only see the smooth arcuate profile from the outside of the packaging article 1712 as the corrugated board material is opaque and the rows of cuts 1748 are internal.

[0153] Generally, the present inventors have found that to form a tight 90° bend in a single wall board of the type described in the embodiments of Figures 1-10, around 10 rows of cuts in a region 35-40mm wide (~4mm between cuts) is a practical limit. A double wall board would typically require 20 rows of cuts in a region approximately 75-80mm wide (~4mm between cuts) to form a tight 90° bend. Such tight bends tend to achieve the best results when the rows of cuts cross the flute direction. Whilst the embodiments above have discussed bends of 90° and 180° it should be noted that bends through other angles are contemplated and that the number and spacing of rows of cuts may be adjusted accordingly.

[0154] It will be appreciated that numerous changes may be made within the scope of the present disclosure. For example, the curved regions may be applied to numerous other types of packaging article, such as basket carriers, where such curved or rounded features are beneficial, including articles that have hitherto not been made from corrugated board due to the difficulty is forming smooth curves from this material. In addition, the different embodiments of patterns of rows of cuts and bridges may be applied to double walled corrugated board, different shapes of curve region, different angles of curve region to flute direction.

Claims

1. A packaging article comprising:a sheet of paperboard material comprising a fluted layer covered by opposing first and second facing layers;a portion of the sheet defining a curve region comprising a plurality of laterally spaced elongate rows of cuts extending at least through the full depth of the first facing layer and not extending through the second facing layer;wherein the curve region is curved with the first facing layer being concave about an axis generally aligned in a direction of the cuts, thereby generating a convex curved outer profile of the second facing layer.

2. The packaging article of claim 1, wherein at least one of the rows of cuts comprise discrete first and second aligned cuts interrupted by an uncut bridge portion.

3. The packaging article of claim 2, wherein the discrete cuts are longer than the bridge portion, for example at least three times longer.

4. The packaging article of claim 2 or claim 3, wherein the bridge portions of at least two adjacent rows of cuts are aligned, optionally wherein the bridge portions of all rows are aligned.

5. The packaging article of any one of claims 2 to 4, wherein the bridge portions of at least two adjacent rows of cuts are staggered, optionally wherein the bridge portions all mutually adjacent rows of cuts are staggered.

6. The packaging article of any preceding claim, wherein the curve region comprises at least three rows of cuts and wherein the rows of cuts are evenly spaced.

7. The packaging article of any preceding claim, wherein at least two rows of cuts are parallel to each other, optionally wherein all the rows of cuts are parallel to each other.

8. The packaging article of claim 7, wherein the at least two rows comprise straight parallel lines or wherein the at least two rows are parallel curves.

9. The packaging article of any preceding claim, wherein the rows terminate with a further uncut bridge portion at an edge of the sheet, for example a bridge of 2mm or more in length.

10. The packaging article of any preceding claim, wherein a lateral spacing between adjacent rows of cuts is between 1mm and 10mm, optionally between 2mm and 7mm.

11. The packaging article of any preceding claim, wherein the curve region comprises at least eight, optionally at least ten, rows of cuts for every 90° of curvature.

12. The packaging article of any preceding claim, wherein at least two rows of cuts are parallel to each other and are in substantially parallel alignment with an axis of flutes of the fluted layer.

13. The packaging article of claim 12, wherein the fluted layer has a spacing between adjacent flutes and the spacing between the at least two rows of cuts is less than or equal to the spacing between the adjacent flutes.

14. The packaging article of any preceding claim, wherein at least one row of cuts is in non-parallel alignment with an axis of flutes of the fluted layer, for example the row of cuts is at substantially 45° or substantially 90° to the axis of the fluted layer.

15. The packaging article of any preceding claim, wherein the curved region comprises at least two rows of cuts arranged to be mutually convergent.

16. The packaging article of claim 15, wherein the curve of the curve region is an arc of a truncated cone.

17. The packaging article of any preceding claim, wherein the curve region is a first curve region and further comprising a second curve region, optionally comprising four curved regions providing smooth curves at four corners of a cuboid packaging article.

18. The packaging article of claim 17, wherein the second curve region comprises rows of cuts extending in a different direction to the first curve region.

19. The packaging article of any one of claims 1 to 11 or claim 14 when dependent upon any one of claims 1 to 11 wherein at least two rows of cuts follow a wave-shaped path.

20. The packaging article of any one of claims 1 to 11 or claim 14 when dependent upon any one of claims 1 to 11 wherein at least two rows of cuts follow a zig-zag path.

21. The packaging article of claim 19 or claim 20, wherein an amplitude of the wave-shape or zig-zag shape is substantially half of a spacing between the at least two rows of cuts.

22. The packaging article of any one of claims 19 to 21, wherein a spacing between the at least two rows of cuts is the same or greater than a spacing between a peak-to-peak pitch of the fluted layer.

23. The packaging article of any preceding claim, wherein the paperboard material comprises a second fluted layer bonded to the first facing layer, and a third facing layer intermediate the first fluted layer and the second fluted layer and bonded to the first fluted layer and the second fluted layer; optionally wherein the rows of cuts additionally extend through the third facing layer.

24. The packaging article of any preceding claim, wherein the packaging article is a cuboid box or a tray comprising a base and side walls.

25. The packaging article of any preceding claim, wherein the curve region is adjoined by first and second substantially planar panels, for example a side panel and an end panel.

26. A blank for forming a packaging article comprising:a sheet of paperboard material comprising a fluted layer covered by opposing first and second facing layers;a portion of the sheet defining a curve region comprising a plurality of laterally spaced elongate rows of cuts extending at least through the full depth of the first facing layer and not extending through the second facing layer;wherein the curve region is configured to be curved with the first facing layer being concave about an axis generally aligned in a direction of the cuts, to thereby generate a convex curved outer profile of the second facing layer.

27. The blank of claim 26, wherein at least one of the rows of cuts comprise discrete first and second aligned cuts interrupted by an uncut bridge portion.

28. The blank of claim 26 or claim 27, wherein a lateral spacing between adjacent rows of cuts is between 1mm and 10mm, optionally between 2mm and 7mm.

29. A method of manufacturing a blank of any of claims 26 to 28, comprising the step of cutting a plurality of laterally spaced elongate rows of cuts through least the full depth of the first facing layer and not through the second facing layer.s

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