GB2518231A

GB2518231A - A blank for forming a carton

Info

Publication number: GB2518231A
Application number: GB1316471.0A
Authority: GB
Inventors: Paul Robertson; Steven Neale
Original assignee: Coveris Flexibles UK Ltd
Current assignee: Coveris Flexibles UK Ltd
Priority date: 2013-09-16
Filing date: 2013-09-16
Publication date: 2015-03-18
Also published as: GB201316471D0

Abstract

A blank 10 for forming a carton for triangular cut sandwiches, the blank comprising first and second substantially rectangular end walls 16, 18 hingedly connected together; first and second triangular side walls 26, 28 hingedly connected to opposing edges 30, 32 of the first end wall; the first of said side walls being subdivided into two triangular side wall panels 26a, 26b with a hinged connection therebetween, the hinged connection extending from the hinged connection between the end walls; the second of said side walls being formed from a single panel; a hinge panel arrangement 36 provided between the second end wall and the second side wall, the hinge panel arrangement comprising first and second panels 36a, 36b, the first hinge panel being hingedly connected to the second end wall, the second hinge panel being hingedly connected to the first hinge panel, and being securable in a face-contacting relationship to the second side wall to facilitate the erection of a carton from the blank; and a securing tab 48 hingedly connected to a free edge of the first side wall for securement in a face-contacting relationship to the second end wall. A lid 56 may be provided with a window 60 and the blank may be formed from paperboard having a layer of plastics film laminated to act as an impermeable barrier.

Description

A blank for forming a carton

FIELD OF THE iNVENTION

The present invention relates to a blank for forming a carton for triangular cut sandwiches. The present invention further relates to a partially erected carton form from such a blank, a carton formed from the blank, and a method of forming a partially erected carton from the blank.

BACKGROUND OF THE iNVENTION

Cartons made from paperboard material for packaging triangular cut sandwiches arc well known and widely used for sandwiches sold in supermarkets, cafes and convenience food outlets. The board is readily printed so that the sandwich is attractively presented on the shelf, the packs are relatively low cost and user-friendly for thc consumer.

In recent years packs that have a laminate of a thin film of plastics material secured to the paperboard by adhesive to act as a liquid and vapour barrier, and to act a "pane" in any viewing openings provided in the carton, have become increasingly popular.

Blanks for such cartons arc manufacturcd on a UV flcxo printing prcss generally along the lines described in the present applicant's earlier application WO200S/099195A1 Such cartons avoid the need to secure a separate "patch window" over viewing openings in the carton, can be cost effectively manufactured at high volume, and have a relatively long shelf life.

An example ofa carton and blank of this type is illustrated in UK design registration 4016190 (St. Neots). Whilst this blank forms a carton with good integrity, the present applicant has recognised that the blank shape, and the orientation in which it needs to be fed through a folder-gluer results in a need for additional glue guns and glue to be used. Further the throughput of blanks being part erected in the folder-gluer is limited by the shape and orientation.

Specifically, the blank as viewed in the first plan, unfolded view in this registration has to be fed from right to lefi as viewed i.e. parallel to the Ibid line that connects the end walls. A two stage folding operation is required in which the leading tab first has to be folded over onto the adjacent portion of the triangular side wall and then the entire lower half as viewed on the page is folded on to the upper half Further, before folding, three glue lines are needed to secure the leading tab to the other side wall (as can be seen in representation 7) and to provide sufficient glue to secure the panel with the dart shape cut out to the adjacent side wall (representation 8), as these are all offset from one another in the feed direction.

The present invention seeks to overcome or at least mitigate the problems of the prior art.

SUMMARY OF THE INVENTION

A first aspect of the present invention provides a blank for forming a carton for titngular cut sandwiches, the blank comprising: first and second substantially rectangular end walls hingcdly connected togcthcr; first and second triangular side walls hingedly connected to opposing edges of the first end wall; the first of said side walls being subdivided into two triangular side wall panels with a hinged connection thcrcbctwccn, the hinged connection extending from the hinged connection between the end walls; the second of said side walls being formed from a single panel; a hinge panel arrangement provided between the second end wall and the second side wall, the hinge panel arrangement comprising first and second panels, the first hinge panel being hingedly connected to the second end wall, the second hinge panel being hingedly connected to the first hinge panel, and being securable in a face-contacting relationship to the second side wall to facilitate the erection of a carton from the blank; and a securing tab hingedly connected to a free edge of the first side wall for sccurcmcnt in a face-contacting relationship to the second end wall. Advantageously, this blank may enable increased throughput in a foldcr-glucr, may reduce the number of glue guns required and reduce overall glue usage.

A lid wall may be hingedly connected to one of the second side wall, first end wall or second end wall, enabling the blank to be self contained and easier to erect.

The blank may further comprise a plurality of flanges hingedly connected to free edges of at least three of the first end wall, the second end wall, the first side wall, the second side wall for securement of a lid thereto in a face-contacting relationship.

Advantageously, this may enable good sealing of lid to rest of carton once loaded.

The blank may be formed from a paperboard substrate having a layer of plastics film laminated to an entire interior face thereof to act as a substantially impermeable barrier. Advantageously this provides a cost effective way of manufacturing blanks with good integrity, when erected.

A portion of the substrate set in from a perimeter of the blank may be cut away to form an aperture and the plastics film extends over the aperture.

The aperture can be in the hinge panel arrangement, which can ease folding and may reduce the thickness of hinge panel so it does not protrude as far into mouth of carton when loading.

A perimeter of the substrate may define a recess and the plastics film may overlies at least a portion of the recess.

The recess may be defined by the second end wall and the securing tab, which may help in simplify the folding operation.

The recess may be defined in the hinge panel arrangement. to reduce the thickness of hinge panel so it doesn't protrude as far into mouth of carton when loading.

A second aspect of the present invention provides a partially erected carton formed from a blank according to the first aspect of the present invention, wherein the securing tab is bonded to the second end wall in a face contacting relationship.

The securing tab may be bonded by a single glue line initially applied to the second end wall, which may in turn simplify gluing and erecting.

The second hinge panel may be bonded to the second side wall panel in a face contacting relationship.

The second hinge panel may bonded by a single glue line initially applied to either the second side wall panel or the second hinge panel, again to simpli' the gluing operation.

The first and second hinge panels are preferably arranged in a substantially coplanar relationship and the first hinge panel is in a face contacting relationship with the second side wall.

The second end wall may be in a face contacting relationship with the first end wall.

The side wall panels of the first side wall may be in a face contacting relationship.

A third aspect of the present invention provides a frilly erected carton formed from a partially erected carton the second aspect of the present invention, wherein the first hinge panel overlies the second hinge panel.

The side wall panels of the first side wall may be substantially coplanar.

A fourth aspect of the present invention provides a method of forming a partially erected carton from a blank of the first aspect of the present invention, the method comprising the steps of: feeding the blank along a folder-glucr machine with the second end wall leading in a direction substantially normal to a leading edge of the second end wall; applying a glue line along the second end wall from a stationary glue gun as the blank is fed along; and bringing the securing tab into a face-contacting relationship with the second end wall so as to be secured thereto by the glue line.

Advantageously, this method may enable faster throughput in folder-glucr machine.

Preferably, the securing tab and adjacent side wall panel arc folded about the hinged connection between the side wall panels to bring the securing tab into a face-contacting relationship with the first end wall and via the film in the recess to assist in pulling the second end wall into contact with the securing tab.

In a further step a second glue line may be applied to at least one of the second hinge panel and second side wall.

The second end wall may be brought into contact with the securing tab, the second hinge panel may also brought into contact with the second side wall and may be secured thereto by the second glue line.

A fifth aspect of the present invention provides a blank for forming a carton for triangular cut sandwiches comprising first and second substantially rectangular end wall panels, panels to form first and second triangular side walls, and a securing tab for securing one of the side walls to one of the end walls, wherein a gusset panel or portion of film spans a spacing between the securing tab and the end wall. The fifth aspect preferably or optionally may include the fcathrcs of the first aspect of the present invention.

BRTEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a plan view of an inner (non printed) face of a blank according to an embodiment of the present invention; Figures 2-5 are perspective views illustrating successive stages of forming a partly erected carton from the blank of Figure 1; and Figure 6 is a perspective view of a substantially erected carton ready to be loaded with a sandwich.

DETAILED DESCRIPTION OF EMBODIMENT(S)

Figure 1 shows a blank 10 for forming a carton for triangular cut sandwiches (see carton of Figure 6). The blank is typically manufactured from a paperboard substrate 12 which provides the majority of the ultimate rigidity of the carton and is covered over its entire inner face with a thin transparent film of plastics material 14 such as polyethylene (PE). The plastics material 14 provides a moisture barrier to hold liquid sandwich ingredients, such as mayonnaise, in the carton, without leaching into the paperboard and compromising its appearance and strength. The film inhibits the release of moisture as vapour from the finished carton so as to extend the shelf life of the sandwich by slowing down the process of it becoming stale. Further the film 14 may help to maintain an atmosphere with the carton that slows the decay of vegetable matter, thrther enhancing the shelf life of certain sandwich varieties.

A blank 10 of the type may be manufactured on a know U\T flexo press with printing, laminating and die cutting stations in accordance with a known press. Suitable presses include those made by Gallus Group UK Limited of Royston, Hertfordshire, UK.

The blank comprises a number of panels, some of which form an entire wall of the finished carton, others of which form part of a wall or a tab/hinge. The various panels are defined and connected by a number of fold lines. The fold lines may be formed by die cutting partially through the papcrboard along some or all of the fold line, cutting substantially all the way through the paperboard along some or all of the fold line, and/or scoring the paperboard along the fold line in known ways.

The blank 10 includes first and second substantially rectangular end walls 16, 18 hingedly connected together by a fold line 20 along theft shorter edges. In this IS embodiment the end walls 16 and 18 are trapezoidal in shape, with edges 22 and 24 remote from theft mutual hinged connection being slightly wider than the edges defined by fold line 20. This arrangement aids in the stacking of cartons erected to the state shown in Figure 6, formed from the blank 10, and with loading the carton with sandwiches (by presenting a wider mouth).

The blank further includes first and second triangular side walls 26 and 28 hingcdly connected to opposing longer edges of the first end wall by fold lines 30 and 32 respectively. The first side wall 26 is subdivided into two triangular side wall panels 26a and 26b with a fold line 34 forming a hinged connection therebetween. This fold line 34 extends from the intersection of the fold lines 20 and 30. The second side wall 28 is formed from a single panel.

A hinge panel arrangement 36 is provided between the second end wall 18 and the second side wall 28. The hinge panel arrangement 36 comprises first and second panels 36a and 36b. The first hinge panel 36a is hingedly connected to the second end wall 18 by a fbld line 38 and the second hinge panel 36b is hingcdly connected to the first hinge panel by a fold line 40, and to the second side wall 28 by a fold line 42.

The panels 36a and 36b are substantially triangular in shape and are provided to enable the blank to be glued, part erected and shipped in a flat format to a packer without a crease being needed in a lid (and window pane) of the blank, as will be

apparent from the description below.

The first and second hinge panels 36a and 36b are substantially the same size, but the second hinge panel 36b comprises a two elongate sections where the paperboard has been cut away. The first section 44 is at a free edge of the panel to define a recess in the panel, is curved at an end closest to fold line 42, and terminates at the fold line 40.

The second section 46 extends from the intersection of fold lines 20, 32, 38 and 42, with two edges defines by fold lines 40 and 42, a further edge running parallel to fold line 40 and then curving around to intersect fold line 40 at substantially 900 to leave a relatively narrow portion of board of the second hinge panel 36b which meets the first hinge panel 36a at the fold line.

A securing tab 48 is hingedly connected to a free edge of the first side wall 26 by a IS fold line 50 and is substantially trapezoidal in shape, defining a triangular recess between the tab and a free edge 52 of the second end wall 18 (the edge opposing fold line 52. In this embodiment, this recess is spanned by a further portion of film 54.

In this embodiment the blank further comprises a lid wall 56 hingedly connected to the second side wall 28 by a fold line 58. In other embodiments, the lid may be separately attachable to the blank at a certain stage of the process for erecting the blank to form a carton. The blank includes a window aperture 60 in the paperboard 12 covered by the film 14. This window may be of various shapes and is intended to enable a prospective purchaser of the sandwich to view the filling. In other embodiments the window may extend into the second side wall (i.e. span the fold line 58, or be omitted entirely.

The blank also comprises a number of flanges intended to seal against the lid wall 56 when the blank is erected. In this embodiment first and second end wall flanges 62 and 64 are hingedly connected to the first and second end walls 16 and 18 via fold lines at edges 22 and 24. First and second side wall flanges 66 and 68 are further hingedly connected to the side wall panels 26a and 26b via fold lines 70 and 72. The lid wall 56 may be provided with a tear tab arrangement (e.g. at a corner) of any known type to assist with opening, once the lid wall is sealed.

Figure 1 further illustrates two glue lines. A first glue line 74 is applied to the second side wall panel 28 substantially normal to and approximately half way along fold line 42. In other embodiments this may be applied to the second hinge panel 36b.

A second glue line 76 is applied to the second end wall 18 and extends along substantially the entire length of the panel between fold line 20 and flange 64, in a direction normal to the fold line 20, and proximate the free edge 52.

The blank leaves the press in the form shown in Figure 1, except for the presence of the glue lines 74 and 76.

Subsequent operations take place on a second machine -a folder-gluer -that may be located downstream of the press in the same facility, or at a different site. Suitable folder-gluers are manufactured by Bobst of Redditch, UK in the "Masterfold" range.

In order for such machines to operate, it is necessary to feed successive blanks 10 through the machine with a straight edge of in excess of a minimum dimension particular to that machine transverse to the feed direction, to act as a datum. For the present blank, the free edge of the flange 64 is used as that datum, and the blanks are fed in a direction X that is at 90° to that free edge. The datum is used to set glue locations and at what position folding is initiated.

The first stage of the partial erection of a carton from the blank is the application of the glue from two static glue nozzles (not shown) provided at suitable locations relative to the inner, film coated face of the blanks 10 as they pass the nozzles.

Typically, hot melt adhesive is applied by the glue nozzles.

Now with reference to Figures 2 to 4, successive stages of folding of the blank 10 as it continues to pass along the folder-gluer are shown.

In Figure 2 the securing tab 48 and side wall panel 26a have been caused to start folding upwardly in the direction of arrow Y about fold line 34. This may be achieved by an compressed air blast from underneath, suction from above, andior a hook arrangement (not shown) engaging the leading edge of tab 48 as the blank continues in direction X, to initiate the folding operation.

The film portion 54 which connects the tab 48 to second end wall 18 then pulls the second end wall upwardly in direction Z, along with the hinge panel arrangement 36, causing these to fold about fold lines 20 and 42 respectively.

The blank is held against upper and lower guides (only upper guides 80 and 82 visible), and the upper guides stop just short of where folding commences in order that folding occurs with respect to the correct fold lines.

Figures 3 and 4 show further stages of this process, and it can be seen that the tab 48 is brought over behind the second end panel 18 in the direction of travel so that it may subsequently be secured thereto by glue line 76. At this stage, as the second end wall 18 and panel 26a are approaching an upright position two further guides 84 and 86 arc positioned so as to contact their leading faces and continue the folding operation.

This brings bring panel 26a at or near to a face-contacting relationship with panel 26b, tab 48 into or near to contact with glue line 76 and second end wall 18, second end wall 18 at or near to contact with first end panel 16, hinge arrangement 36 at or near to contact with second side wall 28, and glue line 74 at or near to contact with second hinge panel 36b.

In a final step, rollers, belts or other suitable guides (not shown) typically compress the overlying faces contact to ensure that the glue is spread and fully holds the respective panels together.

Figure 5 shows a reverse (i.e. underside) view of the partially erected carton 10 formed by thc foldcr-glucr.

The partially erected cartons 10 may then be supplied in this form to a packer which prepares the sandwiches (not shown), opens the carton 10 into the state shown in Figure 6 and loads thc triangular cut sandwich therein. Opening the carton 10 from the fiat state may be achieved easily by folding the panels 26a and 26b of the first side wall 26 out of a face-contacting relationship and into a substantially co-planar relationship, whilst also folding the first and second hinge panels 36a and 36b from a coplanar relationship into an overlying or face-contacting relationship. The cut away sections 46 and 44 have been found to aid in the folding of the hinge panels, and enable the hinge panels to sit close to the second side wall with minimal obstruction of the mouth of the carton, which assists with loading of the sandwich.

Additionally the flanges 62, 64, 66 and 68 are folded outwardly.

Once loaded, the lid wall 56 can be brought into contact with the faces of the flanges 62, 64, 66 and 68, and secured thereto. Typically this may be achieved by heat sealing, as the film 14 face (non-printed) of the lid wall contacts the film face of the flanges, enabling a good heat seal bond. However glue or RE welding may also be used.

It has been found that this particular blank format has enabled increases of up to around 25% in throughput through the foldcr-glucr to be achieved, whilst at the same time minimising the number of glue guns required, and the amount of glue to be used.

The throughput increases are believed to have been possible because of the single IS folding action required, and the fact it occurs in generally the same sense as the feed direction of blanks through the folder-gluer, rather than being at 900 thereto as in the

prior art.

It will be further appreciated that the film portion 54 acts as a barrier at may otherwise be a point at which air and liquid may pass through the carton at the apex where panels 16, 18, 26a and 26b meet, and thereby improves the sealing of the carton.

Although the invention has been described above with reference to one or more prefened embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims. For example the window 60 and cutaway sections 44 and 46 may have different shapes or be omitted altogether. Recess 54 may alternatively be formed as a triangular panel(s) that include at least a portion of paperboard. The blank may be a minor image of that represented in the drawings. The proportions of certain panels may be altered; in particular the end panels and lid so as to accommodate different fill amounts, one or three sandwiches instead of the usual two, or club sandwiches, for example. The blank may be adapted for sandwiches intended to be sold the same day and therefore which require less hermetic sealing. In such cases the flanges may be omitted and some form of tab and slit arrailgement used to secure the lid e.g. the first side wall. The blank may be formed from board co-extruded with a liquid impermeable layer and a patch window used instead of the laminate format described above.

Claims

Claims 1. A blank for forming a carton for triangular cut sandwiches, the blank comprising: a. first and second substantially rectangular end walls hingedly connected together; b. first and second triangular side walls hingedly connected to opposing edges of the first end wall; the first of said side walls being subdivided into two triangular side wall panels with a hinged connection therebetween, the hinged connection extending from the hinged connection between the end walls; the second of said side walls being formed from a single panel; c. a hinge panel arrangement provided between the second end wall and the second side wall, the hinge panel arrangement comprising first and second panels, the first hinge panel being hingedly connected to the second end wall, the second hinge panel being hingedly connected to the first hinge panel, and being securable in a face-contacting relationship to the second side wall to facilitate the erection of a carton from the blank; and d. a securing tab hingedly connected to a free edge of the first side wall for seeurement in a face-contacting relationship to the second end wall.
2. A blank according to claim I further comprising a lid wall hingedly connected to one of the second side wall, first end wall or second end wall.
3. A blank according to claim 1 or claim 2 further comprising a plurality of flanges hingedly connected to free edges of at least three of the first end wall, the second end wall, the first side wall, the second side wall for seeurement of a lid thereto in a face-contacting relationship.
4. A blank according to any preceding claim, wherein the blank is formed from a paperboard substrate having a layer of plastics film laminated to an entire interior face thereof to act as a substantially impermeable barrier.
5. A blank according to claim 4 wherein a portion of the substrate set in from a perimeter of the blank is cut away to form an aperture and the plastics film extends over the aperture.
6. A blank according to claim S wherein the aperture is in the hinge panel arrangement.
7. A blank according to any one of claims 4 to 6 wherein a perimeter of the substrate defines a recess and the plastics film overlies at least a portion of the recess.
8. A blank according to claim 7 wherein the recess is defined by the second end wall and the securing tab.
9. A blank according to claim 7 or claim 8 wherein the recess is defined in the hinge panel anangement.
10. A partially erected carton formed from a blank according to any preceding claim, wherein the securing tab is bonded to the second end wall in a face contacting relationship.
11. A partially erected carton according to claim 10 wherein the securing tab is bonded by a single glue line initially applied to the second end wall.
12. A partially erected carton according to claim 10 or claim 11 wherein the second hinge panel is bonded to the second side wall panel in a face contacting relationship.
13. A partially erected carton according to claim 12 wherein the second hinge panel is bonded by a single glue line initially applied to either the second side wall panel or the second hinge panel.
14. A partially ercctcd carton according to claim 13 wherein the first and second hinge panels arc arranged in a substantially coplanar relationship and the first hinge panel is in a face contacting relationship with the second side wall.
15. A partially erected carton according to any one of claims 10 to 14 wherein the second end wall is in a face contacting relationship with the first end wall.
16. A partially erected carton according to any one of claims 10 to 15 wherein the side wall panels of the first side wall are in a face contacting relationship.
17. A fully erected carton formed from a partially erected carton according to any one of claims 10 to 16 wherein the first hinge panel overlies the second hinge panel.
18. A fully erected carton according to claim 17 wherein the side wall panels of the first side wall are substantially coplanar.
19. A method of forming a partially erected carton from a blank of any one of claims 1 to 9, the method comprising the steps of: a. feeding the blank along a folder-gluer machine with the second end wall leading in a direction substantially normal to a leading edge of the second end wall; b. applying a glue line along the second end wall from a stationary glue gun as the blank is fed along; and c. bringing thc securing tab into a face-contacting relationship with the second end wall so as to be secured thereto by the glue line. [adv: method enables faster throughput in folder-gluer]
20. A method according to claim 19 when dependent upon claim 8 wherein in step c), the securing tab and adjacent side wall panel are folded about the hinged connection between the side wall panels to bring the securing tab into a face-contacting relationship with the first end wall and via the film in the recess to assist in pulling the second end wall into contact with the securing tab.
21. A method according to claim 19 or claim 20 wherein in a fhrthcr step d)prior to step c) a second glue line is applied to at least one of the second hinge panel and second side wall.
22. A method according to claim 21 when dependent upon claim 20 wherein when the second end wall is brought into contact with the securing tab, the second hingepanelisalsobroughtintocontactwiththesecondsidewallandis secured thereto by the second glue line.