GB2253611A - Carton and blank for making the same - Google Patents

Abstract

A carton made from a single blank of cardboard, paperboard or the like has a top having a substantially horizontal uppermost portion 3 and front and rear portions 4, 5 sloping downwardly from said uppermost portion 3. The front portion 4 may receive a dispensing spout 8. The carton is filled by first forming the top of the carton, then filling the carton through the open base and then closing the base. A blank for making the carton has front and rear top-forming panels, and tuck forming panels between the top forming panels and side wall forming panels. Flaps for forming the uppermost surface 3 are attached to the free ends the front and rear top forming panels 4, 5. <IMAGE>

Description

CARTON AND BLANK FOR MAKING THE SAME This invention relates to cartons made of cardboard, paperboard or similar lightweight foldable sheet material, and to blanks for making the same, and is particularly directed to the provision of such a carton for carrying and dispensing liquids such as liquid detergents and having improved qualities of liquid-tightness.

Viewed from one aspect the invention provides a carton made from a single blank of cardboard, paperboard or similar lightweight foldable sheet material and having a base, a front wall, a rear wall, two side walls and a top, the top having an uppermost surface portion which is generally horizontal, a front surface portion which slopes downwardly and forwardly away from the said surface portion and a rear surface portion which slopes downwardly and rearwardly from said uppermost surface portion, one of said sloping surface portions being suitable for receiving a dispensing spout, the said rear surface portion being formed by a rear top panel hingedly connected to the top of the said rear wall, the said front surface portion being formed by a front top panel hingedly connected to the top of the said front wall, and the said front and rear top panels being connected to the said side walls by respective arrays of inwardly folded tuck panels which underlie the said top panels.

Preferably the sloping front surface portion is provided with pouring means in the form of a dispensing spout. This could be of any desired construction, but preferably it is a pouring spout formed of a plastics material. Advantageously the spout has a mounting flange which locates against the inside of the sloping top surface. Preferably, if the carton is formed of thermoplastics coated paperboard, the flange is of a material which has the same or a similar melting point as the thermoplastic coating of the carton material so that it may be fixed thereto by sonic welding. It is particularly advantageous if the pouring spout extends from the sloping surface to a point where it forms a plane with the horizontal top surface. This facilitates stacking, although it will be appreciated that the carton may facilitate stacking solely by virtue of having a horizontal top portion.

Viewed from another aspect the invention provides a one-piece blank made of cardboard, paperboard or similar lightweight foldable sheet material for forming a carton as described above, comprising a row of four hingedly interconnected wall panels for forming the said front, rear and side walls of the carton, an array of baseforming panels on one side of the said row of wallforming panels, front and rear top-forming panels hingedly connected to the respective front and rear wall-forming panels on the other side of the row via respective hinge lines, respective arrays of front and rear tuck-forming panels hingedly connected between the said front and rear top-forming panels and respective side wall-forming panels, the connection between a front tuck-forming panel and a said side wall-forming panel being by way of a first hinge line extending upwardly and rearwardly from the hinge line between said front top-forming panel and said front wall forming panel, the connection between a rear tuck-forming panel and said side wall forming panel being by way of a said hinge line extending upwardly and forwardly from the hinge line between said rear top-forming panel and said rear wall-forming panel, said first and second hinge lines being joined by a third hinge line formed between said side wall-forming panel and a flap arranged between said respective tuck forming panels, and uppermost topforming panel means hingedly connected to said rear and/or front top-forming panels.

During erection of the carton, the front and rear top-forming panels will be folded inwardly over their respective tuck-forming panels, the flap which is hingedly connected to the side wall panel will also be folded inwardly, and the uppermost top forming means folded to overlie the flap.

The uppermost top forming panel means preferably comprises a first flap hinged to one of said front or rear top forming panels and a second flap hinged to the other of said panels. Preferably at least one of said flaps has a height substantially the same as the length of the third hinge line formed at the upper edge of the side wall forming panel. This flap will then extend across the entire uppermost portion of the carton when erected. Preferably both flaps are of this height whereby they completely overlie one another upon erection of the carton.

Preferably the carton is symmetrical about a line bisecting the respective side walls, in which case, the first and second hinge lines in the blank extend inwardly at the same angle, and the hinge lines between the rear top-forming panel and the rear wall forming panel and the front top forming panel and the front wall-forming panel are co-linear.

A front top-forming panel and a rear top-forming panel are connected to a mutually adjacent side-wall forming panel by front and rear tuck-forming panels respectively. The front tuck-forming panel is connected to said side wall-forming panel by the said first hinge line and to the front top-forming panel by a further hinge line. The rear tuck-forming panel is connected to the side wall-forming panel by the said second hinge line and to the rear top-forming panel by a yet further hinge line. Preferably the front and/or rear tuckforming panels have tuck-hinge lines extending upwardly and inwardly from the respective outer ends of the first and second hinge lines, to allow the panels to fold to form the tuck.

In a preferred embodiment, a single tuck hinge line is provided in each panel which angularly bisects the respective front or rear tuck-forming panels.

During assembly, as the front and rear top-forming panels are folded about their respective hinge lines to close the top of the carton, the tuck-forming panels are folded inwardly, about their respective tuck hinge lines to underlie these panels.

As stated above, the flap joined to the top of the side wall forming panel lies between the respective front and rear tuck-forming panels. It is possible that the front and rear tuck-forming panels may be separate from the flap, but in a particularly preferred embodiment, they are joined to it. Thus respective webs of material may extend upwardly from the points of intersection of the hinge lines formed on the upper end of the side wall-forming panels to connect the respective tuck-forming panels to the flap. This will ensure a good seal at the points of intersection, where the slope of the top of the erected carton changes.

To obviate buckling of the tuck-forming panels during folding, the respective webs may be formed so as not to extend to the top edge of the tuck-forming panels. Thus respective cut-outs may be defined between the front and rear tuck-forming panels and the interposed flap which do not extend as far as the hinge line formed in side wall-forming panel.

It would of course be possible to provide the webs with a series of further folds rather than a cut out to achieve the same effect, but the latter is preferred since it puts less stress on any thermoplastic coating material of the carton. A fold line may extend along the web from the side wall panel hinge line to the cutout to facilitate bending of the web..

In the case where the front and rear tuck-forming panels are separate from the flap or where a cut-out is formed between them so that the panels have free, opposing edges, the various panels are preferably shaped such that when the carton is erected, these edges will be adjacent to each other, so that no raw edge of material will be exposed in this region of the erected carton, so as to prevent wicking of liquid contents into the carton material. Furthermore, the length of the flap is preferably such that its free end will, when the carton is assembled be adjacent the free end of the flap provided on the opposite side wall, again so that no raw edge will be exposed in this region.

The heights of the front and rear top-forming panels are preferably substantially the same as the length of the adjacent hinge line joining the tuckforming panels to the side walls. In this way when the carton is erected, the respective top-forming panels will meet along the junction between the horizontal and sloping areas of the top.

It will be appreciated that only the panels provided on one side wall-forming panel have been described above. In the preferred construction, the other side wall-forming panel is provided on its upper edge with tuck-forming panels and flaps which are a mirror image of those on the one panel.

The blank may have a securing strip extending along the edge of one of the outer side forming panels.

During assembly, the outer surface of the securing strip is adhered by suitable means to the inside edge of the adjacent side wall-forming panel to form a tubular blank.

The invention also provides, from another aspect, a method of filling a carton as described above comprising the steps of forming the top of the carton, then filling the carton through the open base with the carton inverted, and then closing the base of the carton.

In more detail, the procedure of forming and filling a carton according to the invention may comprise, firstly, forming the carton blank into an open-ended tubular structure by securing the terminal walls of the row to each other, for example by means of a conventional flamesealing strip provided at one end of the row. A pouring spout, if required, may then be attached to the tubular structure. Preferably, as stated above, the spout is formed with a flange which engages around the back of a hole formed in the sloping top panel, the flange being of a thermoplastics material with the same or similar melting point as the thermoplastics coating material of the carton, so that the flange may be attached to the carton by heating or ultrasonic welding.

With the spout attached, the top of the carton is then formed. The tubular structure, with its top prefolded, may be placed on a mandrel and hot air directed at those parts of the top where it is desired to melt the thermoplastic coating for adhesive purposes. The top-forming and tuck-forming panels are then folded into their final positions and the top closure clamped firmly between an anvil and the mandrel to ensure that good contact is obtained between the components to achieve a good seal. Of course other ways of adhering the various components of the top closure to one another can be envisaged such as selective application of adhesive.

The top could also be ultrasonically welded on the mandrel.

Once the top closure has been formed, the carton may be filled with a chosen liquid such as a detergent, a dairy produce or a food product for example.

Once filled, the base is then formed. The base of the carton may be of any convenient kind. However one advantageous construction is of the type commonly seen in cartons containing fruit juices and the like. In this arrangement, base-forming panels are joined to the bottom edges of the side wall-forming panels along colinear hinge lines, with a further hinge line extending along the base-forming panels parallel to the colinear hinge lines to form a strip of sealing panels between the hinge line and the terminal edge of the blank. The base-forming panels attached to the side wall-forming panels having the top-forming panels have further hinge lines extending inwardly from their upper corners to the parallel hinge line to define a triangular panel, and a vertical hinge line extending from the parallel hinge line to the free edge of the blank.

Such a bottom closure will be closed in the following manner. Firstly, the triangular portions referred to above are pulled outwardly and the closure panels on the other two walls pushed inwardly to bring opposed surfaces of the sealing panels together. These are then heated and pressed together by for example a plough arrangement to form an upstanding fin which is then folded onto and adhered to the flattened closure panels with finally the triangular closure panels being folded over on top of both and adhered thereto.

This method of construction allows the folds in the top of the carton to be secured firmly in position on a mandrel and a substantially flat bottom surface to be provided on the carton.

One embodiment of the invention will now be described, by way of example, with reference to the following drawings in which: Figure 1 shows a carton in accordance with the invention; Figure 2 shows a carton blank from which the carton of Figure 1 is erected; Figure 3 shows an intermediate stage in the erection of a carton in accordance with the invention; and Figure 4 shows a later stage in the erection of the carton.

With reference to Figure 1, a carton 1 for holding liquid detergents or the like is formed from one-piece blank of thermoplastics coated paperboard and has a top 2 with an uppermost, substantially horizontal, portion 3 a front, downwardly sloping, portion 4 and a rear, donwardly sloping portions. The front and rear portions 4,5 are formed by respective rear and front top-forming panels ( Fig. 3) hingedly attached to the front and rear walls 6,7 respectively. A screw topped pouring spout 8 with a removable cap is provided in the sloping portion 4. The top of the pouring spout 7 may lie in the same plane as the horizontal portion 3, which facilitates stacking of the cartons.

The above carton may be produced from a blank as shown in Figure 2. With reference to that Figure, a cut and scored blank 10 has four side wall-forming panels 11-14 and a securing strip 15. These panels are joined along hinge, fold or score lines 16-19. The blank is also formed with a top closure 20 and base closure 21.

Top closure 20 comprises front and rear top-forming panels 22,23 which are connected to the upper edges of the front and rear wall-forming panels 12,13 respectively along co-linear straight hinge lines 24,25.

Uppermost top-forming flaps 26,27 are hinged to the front and rear top panels 20,23 by hinge lines 28,29.

The top closure also comprises a arrays of tuckforming panels 32,33,32',33' which are connected to the upper edges of side wall-forming panels 11,13 along respective, angled hinge lines 34,35,34',35'. The hinge lines 34,35 on the upper edges of panel 11 are connected by a further hinge line 38, and those on the other panel 13 by a hinge line 38'. Flaps 40,40' are connected to these respective hinge lines 38,38', which are parallel to the hinge lines 24,25 between the respective front and rear top forming panel 23 and the rear side wallforming panel 14. The lengths of the hinge lines 34,35,34',35' are substantially equal to the height of the front and rear top-forming panels 22,23.

The tuck-forming panels, joined to the side wallforming panel 13 each comprise respective front and rear tuck-forming panels 32,33. Front tuck-forming panel 32 is joined to the front top-forming panel 22 along hinge line 42 and to the side wall panel 13 along hinge line 34. It is formed with a single tuck-hinge line 43 which generally bisects the panel 32. The rear tuck-forming panel 33 is joined to the rear top-forming panel 23 along hinge line 44 and to the side wall-forming panel 13 along hinge line 35 and formed with a tuck-hinge line 45 which bisects the panel 33. Panels 32 and 33 are generally kite-shaped.

The first and second tuck-forming panels 32,33 are joined to the flap 40 by respective webs 46,47 of material. Fold lines 48,49 bisect the webs 46,47. The webs 46,47 do not extend to the uppermost edges of the respective first and second tuck-forming panels 32,33 and respective cut-outs 48,49 are thus defined between the opposed edges 50,51 of the tuck-forming panels and the side edges 52,53 of the flap 41. The respective cut-out 48,49 are shaped such that when the carton is erected the opposed edges will lie adjacent each other.

Furthermore, since the tu-forming panels 32,33 are substantially symmetrical about the respective tuckhinge lines 35,37, maximum overlap of these panels will be achieved upon erection of the blank for good adhesion and sealing.

The array of panels joined to the top edge of sidewall forming panel 11 is a mirror image of that on the top edge of panel 13 and corresponding features are indicated by the reference numerals 32'-53'. In this array, however, there is of course no hinge line corresponding to hinge line 44, since when the carton is erected, tuck-forming panel 33' will be adhered to the upper portion 54 of the securing strip 15, with the hinge lines 55,56 in the latter coinciding with hinge lines 37',45' respectively. The tuck-forming panel 33' will therefore effectively be hingedly connected to the rear top-forming panel 23 by the hinge line 57 at the upper inner edge of the sealing strip 15.

The panel 22 has an aperture 58 for accepting a pouring spout as will be described later.

Turning now to the base of the container, the base closure 22 comprises an array of base-forming panels 5962 connected to the bottom edges of the side wall panels 11-14 along a hinge line 63. Parallel to hinge line 63 there is a further hinge line 64 which together with hinge line 63 defines a sealing strip 65 made up from a plurality of panels 66-69. Hinge lines 70-73 in panels 60-62 divide the panels 60-62 into triangular portions.

Further hinge lines 74,75 extend from the apex of the central triangular portion of each panel to the free edge of the strip 65.

The erection of the carton as described above will now be explained.

After cutting and scoring the blank by conventional methods, it is first erected into a tubular structure 66 by folding along the hinge lines 16-19 and sealing the outer surface of the securing strip 15 to the inner surface of opposed panel 11. As stated above, hinge lines 56 and 45' are aligned. The sealing may be achieved by any conventional method e.g. flamesealing.

After this, the pouring spout 7 may be attached to the front top-forming panel 22. This is done by passing the spout 7 through the aperture 58 from the inside until a flange at its base abuts the inner surface of the panel 22 around the aperture 58. This may then be secured on the surface by, for example, ultrasonic welding. The spout 7 could, alternatively, be added after formation of the top closure, which will now be described.

With reference to Figure 3, the top closure 2 is is formed with the tubular structure 76 erected from the blank 10 being placed on a mandrel (not shown). The front and rear top-forming panels 22, 23 are pushed together (by means not shown) with the tuck-forming panels 32,33,32',33' being folded inwardly about their respective tuck-hinge lines 43,45 and 43',45' to lie under the panels 22,23.

The flaps 40,40' are folded about hinge lines 38,38' so as to lie generally horizontally. Finally, the flaps 26,27 are folded over the flaps 40,40' to form the uppermost surface. The flap 26 will substantially completely overlap flap 27.

To achieve a good seal, substantially the whole overlapping areas of the tuck-forming panels 32,33', 32',33 are adhered to one another, as are the flaps 26,27. This may conveniently be done by melting the thermoplastic coating on these portions by, for example, hot air jets and pressing them together between the mandrel and an anvil. In this way a substantial pressure may be applied in order to properly form the folds and achieve good sealing between the various panels. The top could alternatively be ultrasonically welded on the mandrel.

The cut-outs 48,49,48',49' allow the tuck-forming panels 32,'33,32',33' and flaps 41 to fold inwardly without substantial buckling. This means that the thermoplastics coating on the carton material in this region will not he ruptured. After assembly, the opposed edges 50,51,52,50',51',52' of the tuck forming panels 32, 33, 32', 33' and flaps 40,40' will lie substantially adjacent one another. Furthermore, the length of the flaps 40,40' may be such that the free ends thereof substantially abut one another. The length of the edges 50,51,52,53 may also be substantially equal, so that no raw edge of material is exposed within the carton top.When the thermoplastics coating of the carton material is heated during sealing, the melted plastics will run into the gaps between the opposed edges so as to seal the edges from liquid in the carton.

Once the top closure is formed, the carton may be filled with liquid to a predetermined level, after which the base is formed. Panels 59 and 61 are pushed together while panels 60 and 62 are pulled outwardly, in order that the sealing strip panels 65-69 overlie one another. Opposed sealing strip panels are then adhered together to form a sealing fin 79 upstanding from a substantially flat base having a rectangular portion and a triangular flap 81,82, at either end, as shown in Figure 4. This may be done by melting the thermoplastic coating on the inner surfaces of the sealing panels 6669 and pressing them together with a plough or roller arrangement.The sealing fin 79 is then folded over in the direction of arrow A and sealed onto the rectangular base portion 80, after which the triangular flaps 81, 82 are folded back on to and adhered to the base surface 80, as shown by the arrows B.

It will be noted that the bottom edge of the sealing strip 15 is attached to the inner surface of sealing panel 65, which gives a very satisfactory seal in this area.

The above method of construction allows the folds of the top closure to be sealed effectively under considerable pressure, while allowing a substantially flat base to be formed after the carton has been filled.

It is to be clearly understood that there are no particular features of the foregoing specification, or of any claims appended hereto, which are at present regarded as being essential to the performance of the present invention, and that any one or more of such features or combinations thereof may therefore be included in, added to, omitted from or deleted from any of such claims if and when amended during the prosecution of this application or in the filing or prosecution of any divisional application based thereon.

Furthermore the manner in which any of such features of the specification or claims are described or defined may be amended, broadened or otherwise modified in any manner which falls within the knowledge of a person skilled in the relevant art, for example so as to encompass, either implicitly or explicitly, equivalents or generalisations thereof.

Claims (19)

CLAIMS:

1. Viewed from one aspect the invention provides a carton made from a single blank of cardboard, paperboard or similar lightweight foldable sheet material and having a base, a front wall, a rear wall, two side walls and a top, the top having an uppermost surface portion which is generally horizontal, a front surface portion which slopes downwardly and forwardly away from the said surface portion and a rear surface portion which slopes downwardly and rearwardly from said uppermost surface portion, one of said sloping surface portions being suitable for receiving a dispensing spout, the said rear surface portion being formed by a rear top panel hingedly connected to the top of the said rear wall, the said front surface portion being formed by a front top panel hingedly connected to the top of the said front wall, and the said front and rear top panels being connected to the said side walls by respective arrays of inwardly folded tuck panels which underlie the said top panels.

2. A carton as claimed in claim 1 wherein the sloping front surface portion is provided with pouring means in the form of a dispensing spout.

3. A carton as claimed in claim 2 wherein the pouring spout extends from the sloping surface to a point where it forms a plane with the horizontal top surface.

4. A one-piece blank made of cardboard, paperboard or similar lightweight foldable sheet material for forming a carton as described above, comprising a row of four hingedly interconnected wall panels for forming the said front, rear and side walls of the carton, an array of base-forming panels on one side of the said row of wallforming panels, front and rear top-forming panels hingedly connected to the respective front and rear wall-forming panels on the other side of the row via respective hinge lines, respective arrays of front and rear tuck-forming panels hingedly connected between the said front and rear top-forming panels and respective side wall-forming panels, the connection between a front tuck-forming panel and a said side wall-forming panel being by way of a first hinge line extending upwardly and rearwardly from the hinge line between said front top-forming panel and said front wall forming panel, the connection between a rear tuck-forming panel and said side wall forming panel being by way of a said hinge line extending upwardly and forwardly from the hinge line between said rear top-forming panel and said rear wall-forming panel, said first and second hinge lines being joined by a third hinge line formed between said side wall-forming panel and a flap arranged between said respective tuck forming panels, and uppermost topforming panel means hingedly connected to said rear and/or front top-forming panels.

5. A blank as claimed in claim 4 wherein said upmost top-forming panel means comprises a first flap hinged to one of said front or rear top forming panels and a second flap hinged to the other of said panels.

6. A blank as claimed in claim 5 wherein at least one of said flaps has a height substantially the same as the length of the third hinge line formed at the upper edge of the side wall forming panel.

7. A blank as claimed in claim 6 wherein both flaps are of this height whereby they completely overlie one another upon erection of the carton.

8. A blank as claimed in any of claims 4 to 7 wherein first and second hinge lines in the blank extend inwardly at the same angle, and the hinge lines between the rear top-forming panel and the rear wall forming panel and the front top forming panel and the front wall-forming panel are co-linear.

9. A blank as claimed in any of claims 4 to 8 wherein the front and/or rear tuck-forming panels have tuckhinge lines extending upwardly and inwardly from the respective outer ends of the first and second hinge lines, to allow the panels to fold to form the tuck.

10. A blank as claimed in claim 9 wherein a single tuck hinge line is provided in each panel which angularly bisects the respective front or rear tuck-forming panels.

11. A blank as claimed in any of claims 4 to 10 wherein said flap joined to the top of the sidewall forming panel is joined to adjacent front and rear back-forming panels.

12. A blank as claimed in claim 11 wherein said join is by means of respective webs of material extending upwardly from the points of intersection of the hinge lines formed on the upper end of the side wall-forming panels.

13. A blank as claimed in claim 12 wherein the respective webs are formed so as not to extend to the top edge of the tuck-forming panels.

14. A blank as claimed in any of claims 4 to 13 wherein opposed edges of the flap joined to the top of the side wall-forming panel and the front and/or rear tuck forming panels are so arranged that when the carton is erected, these edges will be adjacent to each other.

15. A blank as claimed in any of claims 4 to 14 wherein the length of said flap is such that when the carton is assembled, its free end will be adjacent the free end of a flap provided on an opposite side wall.

16. A method as filling a carton formed from a blank as claimed in any of claims 4 to 15 comprising forming the body and top of the carton, filling the carton through the open carton with the carton inverted, and then closing the base of the carton.

17. A method as claimed in claim 16 wherein a pouring spout is attached to a top forming panel prior to forming the top.

18. A method as claimed in claim 17 wherein the blank is formed of thermoplastic coated paperboard, and the flange is of a material which has a similar melting point to the thermoplastic coating of the blank material, and including to step of sonically welding the flange to the inner surface of the front top-forming panel around the said spout receiving aperture.

19. A method as claimed in any of claims 15 to 18 wherein, to form the top, the tubular carton body is placed on a mandrel and hot air is directed at those parts of the top where it is desired to melt the thermoplastic coating for adhesive purposes, the topforming and tuck-forming panels then being folded into their final positions and the top closure clamped between an anvil and the mandrel.