The present invention relates to a carton and, in particular, to a carton which may be used to carry a liquid or food-based product.

Cartons for carrying liquid or food-based products are known. An example of such a carton is described in US9,403,618. However, the problem with such known cartons is that they are typically sealed via a hot melt sealing system, which is a relatively expensive and time-consuming process.

According to a first aspect of the invention, there is provided a carton comprising a carton body, a base element and a pair of opposing closure flaps, wherein the carton body has a top portion that has a rectangular cross-section and a bottom portion that has a circular cross-section; the base element is a circular disc that is sealingly secured to the bottom portion of the carton body; and the closure flaps extend upwardly from the top portion of the carton body, the closure flaps defining an open configuration in which they are spaced apart to provide access to a cavity defined by the carton body and the base element, and a closed configuration in which the opposed closure flaps contact each other; and wherein at least one of the closure flaps include a sealing element which seals together the closure flaps in their closed configuration.

The transition from a rectangular top portion to a circular bottom portion of the carton body means that the base element can be a simple disc, separate from the carton body, which can be ultrasonically welded to the bottom portion of the carton body. This arrangement makes the carton blank easier to produce, as it does not need to include a base portion. It also makes the assembly of the cartons easier, as the blank does not need to be folded and then heat sealed to from a sealed base portion from the blank. Instead, a simple disc-shaped base element is ultrasonically welded to the bottom portion of the carton body, which is a faster, cheaper and simpler process.

In an embodiment of the invention, the carton body tapers outwards from its bottom portion to its top portion. Such an arrangement permits the assembled, but empty, cartons to be stacked for storage and transportation, as each carton is stackable within the carton below it to form a compact arrangement of the cartons. In a further embodiment of the invention, the opposed closure flaps define a pair of opposed gables in the closed configuration. In this embodiment, an essentially linear closure portion is defined from the rectangular-shaped top portion of the carton body. An essentially linear closure portion is easier to seal when the closure flaps are in their closed configuration.

The sealing element may comprise a layer or strip of adhesive. The adhesive material may be applied directly to one or both of the closure flaps or it may be applied as an adhesive tape or strip. In other words, the sealing element may comprise a tape which has an adhesive layer applied to both surfaces thereof.

The adhesive strip or layer may further include a release tape or layer which overlies the adhesive in the open configuration. In such embodiments, the adhesive layer or strip is protected prior to a user wishing to seal the carton once filled. After filling, the release tape may be removed from the adhesive and the carton then sealed. The skilled person will understand that a release tape is a tape which is detachably coupled to the adhesive and is only weakly adhered to the adhesive. The release tape is readily detached from the adhesive without significantly weakening or negatively impacting the adhesive properties of the adhesive.

In an embodiment of the invention, one of the closure flaps includes an adhesive strip provided along the entirety of its length, wherein the adhesive strip includes a release tape.

After sealing, it is desired to be able to readily access the cavity defined by the carton.

Accordingly, the carton may include an opening. Thus, in an embodiment of the invention, one or both of the opposed closure flaps includes one or more lines of weakness provided between a first portion and a second portion of the respective closure flap. The first and second portions of the respective closure flap may be separated by urging open the line of weakness. The line(s) of weakness may be defined by perforations.

A split may be defined in the or each closure flap by urging apart the first and second portions. This may in turn define an exit path from the cavity, for example in the form of a spout.

Additionally or alternatively, the line or lines of weakness may define a detachable portion in one of the closure flaps or both of the closure flaps which provides access to the cavity defined by the carton when the detachable portion is detached. In an embodiment of the invention, the carton further includes a handle element extending upwards from one or both of the opposed closure flaps. Thus, one of the closure flaps may define a handle element which projects upwardly therefrom or both of the closure flaps may define a respective handle element and together, the handle elements define a handle which projects upwardly from the closure flaps.

The sealing element of the invention is used to seal together the opposed closure flaps after the carton has been filed with a product. Optionally, the sealing element may be a tamper-evident sealing element. Tamper-evident seals are well known and indicate if the seal has been broken.

In an embodiment of the invention, the carton is formed from a biodegradable material. Thus, the carton body, the base element and the opposed closure flaps may all be formed from a biodegradable material. Optionally, the carton body and the closure flaps may both be formed from the same biodegradable material. The base element may also be formed from the same biodegradable material or it may be formed from a different material, which may also be biodegradable.

The carton may be formed from a cellulose-based material, such as a cardboard material. Thus, the carton body, the base element and the opposed closure flaps may all be formed from a cellulose-base material, such as a cardboard material. The cellulose-based material may be coated with a coating, such as a polymeric coating, in order to provide a liquid-proof material such that the carton is capable of containing liquid products.

An advantage of providing a base element in the form of a circular disc is that the base element may be ultrasonically welded to the carton body more easily. Thus, in an embodiment of the invention, the carton comprises a base element that is welded, e.g. ultrasonically welded, to the bottom portion of the carton body.

In order to facilitate the welding of the base element to the bottom portion of the carton body, the bottom portion of the carton body may define an inwardly projecting lip or ledge to which the base element is secured. Thus, the inwardly projecting lip or ledge is suitably a radially inwardly projecting lip which supports an outer peripheral portion of the base element. It is desirable to minimise the number of components required to form the carton. Accordingly, the carton body and the opposed closure flaps may be formed together as a unitary or monolithic component. For example, the carton body and the opposed closure flaps may be produced from a flat or planar carton blank. The blank may then be formed into a three-dimensional carton shape. This may be achieved by securing together the opposing ends of the carton blank. The radially inwardly projecting lip or ledge may then be formed at the bottom of the carton body and the base element may then be sealingly secured to the lip or ledge, for example by welding.

The skilled person will appreciate that the rectangular upper portion of the carton body permits it to be closed in a manner that is conventional for rectangular cartons using the opposed closure flaps. Furthermore, the bottom portion of the carton body having a circular cross-section permits a circular, disc-like base element to be used to close the bottom of the carton and to be welded to the carton body, which is a quicker and easier process than closing a bottom portion of the rectangular carton.

As an additional benefit, a carton having a bottom portion which has a circular cross-section may be located in conventional cup-holders and the like.

The skilled person will appreciate that the features described and defined in connection with the aspects of the invention and the embodiments thereof may be combined in any combination, regardless of whether the specific combination is expressly mentioned herein. Thus, all such combinations are considered to be made available to the skilled person.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure la shows a plan view of a carton blank to form a carton according to a first embodiment of the invention;

Figure lb shows a plan view of a base element for use with the carton according to the invention;

Figure 2 shows a perspective view of a bottom portion of a formed carton according to the first embodiment of the invention;

Figure 3 shows a perspective view from above of the formed carton shown in Figure 2; and Figure 4 shows a second embodiment of the invention which includes an alternative perforated portion of the closure flaps which defines a spout for the carton.

For the avoidance of doubt, the skilled person will appreciate that in this specification, the terms "up", "down", "front", "rear", "upper", "lower", "width", etc. refer to the orientation of the components as found in the example when installed for normal use as shown in the Figures.

Figure la shows a carton blank 2 which defines an upper portion 4 which has a rectangular cross- section in an assembled configuration and a lower portion 6 which has a circular cross-section in an assembled configuration.

The upper portion 4 of the carton blank 2 defines a rectangular front wall 8, a rectangular rear wall which is formed from a first rear wall portion 10a and a second rear wall portion 10b and a pair of gabled side portions 12, 14. Each of the gabled side portions 12, 14 are defined by first triangular side walls 12a, 14a; second triangular side walls 12b, 14b; and triangular base portions 12c, 14c.

A front closure flap 16 extends upwardly from the front wall 8, side wall 12b and side wall 14a. A corresponding rear closure flap 18 extends upwardly from the rear wall portions 10a, 10b, side wall 12a and side wall 14b.

A tamper-evident sealing strip of adhesive 20 is applied to the front closure flap 16. The adhesive strip includes a sheet of release paper (not shown) which covers an outwardly facing surface of the adhesive. Such adhesive strips are well known in the art and need not be described in detail herein.

A front handle portion 22 projects upwards from a central portion of the front closure flap 16. A rear handle portion is formed from two rear handle portions 24a, 24b, which project upwards from corresponding portions of the rear closure flap 18.

A series of perforations 26a are provided through a portion of the rear closure flap 18. A corresponding series of perforations 28a are provided through a portion of the front closure flap 16 and the adhesive strip 20. A third series of perforations 26b, 26c, 28b are formed through the side wall 12a (26b), the base portion 12c (26c) and the side wall 12b (28b). Together, the perforations 26a, 26b, 26c, 28a, 28b define a detachable portion 30 of the closure flaps 16, 18 that extend upwards from the gabled side portion 12 and a part of the gabled side portion 12. When the detachable portion 30 is detached from the gabled side portion 12, the gabled side portion 12 defines a spout which is open to the cavity defined by the carton blank 2 in its assembled configuration.

The lower portion 6 of the carton blank 2 defines a lip portion 32, which is radially inwardly folded when the carton blank 2 is in its assembled configuration to define a radially inwardly extending lip around the bottom on the carton.

The carton blank 2 is formed from a relatively thin sheet of a cardboard material which is coated on one side with a polymeric coating. Such material are well known for use in the manufacture of cartons for transporting food or liquid products.

Figure lb shows a base element 34 in the form of a disc of the same cardboard material that is used to form the carton blank 2.

To assemble a carton 102 from the carton blank 2, a first side edge portion 36 of the carton blank 2 is arranged to overly a second edge portion 38 of the carton blank 2 and is secured thereto in a conventional manner, for example via a hot melt adhesive seal or via ultrasonic welding, to form a liquid-tight seal. In this way, the rear wall portions 10a, 10b are arranged adjacent to each other and together define a rear wall 10 which opposes the front wall 8. Similarly, the side portion 12 is located opposite to the side portion 14. Additionally, the two rear handle portions 24a, 24b are arranged to be opposite to the front handle portion 22 and the rear closure flap 18 is opposite the front closure flap 16 which carries the protected adhesive strip 20.

The lip portion 32 is then folded inwards to define the radially inwardly projecting lip. The base element 34 is located on the lip 32 and ultrasonically welded to the lip to form a liquid-tight seal.

Figure 2 shows a bottom view of the carton 102

The assembled carton is then ready for filling with a product and then sealed in a closed configuration. Figure 3 shows a perspective view of the carton 102 in its closed and sealed configuration.

Figure 4 shows a carton 202 according to a second embodiment of the invention. In this embodiment, the carton 202 is similar to the carton 102 which is formed from the carton blank 2, except for the handle and the perforated detachable portion.

Accordingly, the carton 202 has a front wall 208, a rear wall (not shown in Figure 4) a left gabled side portion (shown by a triangular side wall 212b) and a right gabled side portion (shown by triangular side walls 214a, 214b). A front closure flap 216 is provided which projects upwardly from the front wall 208, the side wall 212b and the side wall 214a. As with the first embodiment of the carton 102 described above, the front closure flap 216 carries an adhesive strip 220.

A handle 222 is defined by handle portions which project upwardly from the front and rear closure flaps (only the front closure flap 216 is shown in Figure 4).

In this embodiment, perforations are formed through a portion of the front and rear closure flaps and through the triangular side walls 214a, 214b to define a detachable portion 230.

As shown in Figure 4, when the detachable portion 230 is detached from the remainder of the carton 202, a spout 250 is defined, which is open to the interior cavity defined by the carton 202.