The present invention relates to a closure for a container such as a carton, commonly used to hold liquid, food products, such as fruit juice, milk etc. The closure according to the invention is particularly suitable for cartons having planar ends and is designed to be welded to the container rather than being fixed thereto using adhesives. The closure is flat and substantially planar, allowing cartons, with the closure affixed thereto, to be stacked conveniently.[0001]
Such substantially planar closures are well known in the prior art. Conventionally, such closures have a base with an orifice therein and a conveniently located pouring lip for directing the fluid flow from the container. The carton is also provided with a pouring orifice, normally sealed with foil, which can be torn away before first use of the carton. The closure base is attached to the carton surrounding the foil sealed orifice and is arranged such that the foil can be torn away through the closure orifice, allowing the carton contents to be dispensed. Normally such carton closures also comprise a lid hinged to the base and arranged to snap engage around the pouring lip when the lid is in its closed position.[0002]
On first use, a consumer opens the lid, tears away the foil, revealing the dispensing aperture and dispenses the contents of the carton, using the pouring lip to guide the fluid flow. Thus, the foil acts both to seal the dispensing aperture and also acts as a tamper evidence indicator.[0003]
However, there are a number of disadvantages associated with this type of closure. The closure is usually fixed to the container around the foil sealed dispensing orifice using adhesives. Over time, these adhesives can degrade and the closure may become partially detached from the container resulting in spills, after the foil is removed. Furthermore, sometimes the closure is misaligned relative to the carton and the pull-tab on the foil is trapped between the closure and the carton, such that the foil cannot be torn away from the dispensing aperture. Furthermore, a user can only determine whether the foil has been torn away by opening the closure cover. Therefore, the tamper evidence feature of the foil can only be inspected when the closure cover is open. Finally, when the closure cover is re-closed after use, the snap engagement between the lid and the pouring lip is insufficient to provide an adequate seal, which results in more rapid deterioration of the product and may also lead to leaks from the closure.[0004]
The aim of the invention is to overcome these problems by providing a closure which can be fixed to a container more reliably, using conventional welding techniques, such as ultrasonic welding or heat sealing. The disadvantage of such techniques is that they require a suitable area of overlapping material, to provide a reasonable weld. Thus, the use of such techniques has been limited to welding closures to containers where the closure base comprises a pour spout in the form of a chimney, surrounded by a flange, which can be welded to the container. The disadvantage of this arrangement is that the pouring spout projects from the surface of the carton making it unsuitable for planar end cartons, which need to be capable of being stacked. Furthermore, if this technique is applied to a planar closure having a pouring lip, the provision of a welding flange means that the pouring lip cannot be aligned with the edge of the carton, resulting in unsatisfactory pouring performance.[0005]
Accordingly, the present invention provides a closure for a carton, comprising a base defining a dispensing orifice and a pouring lip, and a lid hinged to the base and adapted to cover the pouring lip when the lid is in its closed position, characterised in that, the base further defines a welding zone surrounding the dispensing orifice but inside the periphery of the pouring lip, thereby allowing the closure to be welded to the carton, with the pouring lip aligned with the edge of the carton.[0006]
The closure according to the invention is arranged such that it has an orifice for dispensing the contents of the carton, a pouring lip for directing the flow of fluid from the carton and between the two, a zone of material, which allows the closure to be welded to the carton using, for example ultrasonic welding or heat sealing. The welding zone extends around the dispensing orifice, providing a sealed flow path through the dispensing orifice and therefore preventing leaks between the carton and the closure. Advantageously, the closure is moulded with the lid in its open position and the closure is welded to the carton with the lid still in this position, exposing the welding zone on the base of the closure. Subsequently, the lid is closed against the base, forming a flat closure with a low profile and thereby allowing the filled cartons to be stacked easily.[0007]
Unlike the conventional rectangular carton closures of this type, the closure according to the invention is preferably substantially square and the pouring lip extends around two adjacent sides of the square. The closure is fixed to the carton at a corner, with the pouring lip aligned with the adjacent edges of the carton. Thus, pouring is effected from the corner of the carton and the corner is used to assist the direction of the fluid flow from the container.[0008]
Preferably, the lid and the orifice in the base have complimentary formations, which together form a bore seal when the lid is in its closed position. This arrangement allows the closure to be re-sealed, even after first opening, improving the life of the product on the carton and preventing spills.[0009]
Advantageously, the closure also has a tamper-evident feature, to indicate whether the lid of the closure has been opened. Preferably, the base or the lid has a tab connected to the remainder to the lid or base by a frangible connection (for example, thin frangible bridges). When the lid is closed on the filling line, the tab is locked in this closed position by a tooth on the complimentary part of the lid or base. The frangible connection is arranged such that any attempt to open the lid of the closure will break the connection, providing visible tamper-evidence, indicating that the closure has already been opened. The tab may be arranged such that it is completely detached on first opening or preferably it may be arranged such that it remains connected to the base or lid by a non-frangible portion. Preferably, on opening of the lid for the first time, this non-frangible portion is irreversibly deformed, such that the tab cannot be rebuilt in its original state in a visibly unobtrusive manner.[0010]
Referring to FIGS.[0016]1 to3, showing aclosure1 according to the invention fixed to acarton2. Theclosure1 comprises abase3 and alid4, hinged to thebase3 and moveable between a closed position and an open position (see FIG. 2). Thebase3 is substantially square and defines a dispensingorifice5 and apouring lip6, which extends around two adjacent sides of the square, allowing the contents of the container to be poured from the corner of thecarton2. Awelding zone7 is defined surrounding theorifice5 inside the periphery of thepouring lip6. Thewelding zone7 is a substantially flat zone of material, which can be used to weld theclosure1 to thecarton2 using ultrasonic welding, heat sealing or similar methods. Provision of awelding zone7 inside the periphery of thepouring lip6, allows theclosure1 to be arranged on thecarton2, with thepouring lip6 aligned with the edge or edges of the carton2 (as shown in FIGS. 1 and 2). This improves the quality of pour from thecarton2 and there is less chance of the product wetting the surface of the carton Referring to FIGS. 1 and 2, achimney41 extends from the underside of the lid and is adapted to engage with theorifice5 in thebase3 to form a bore seal. Thelid4 also has anedge42, which is designed to snap over thepouring lip6. Thebase3 has aperipheral wall31 extending around its periphery to contain any spills within theclosure1. On two sides of thebase3, theperipheral wall31 is adapted to define thepouring lip6.
Finally, as shown in FIGS.[0018]1 to3, theclosure1 is also provided with a tamper evidence feature to visibly indicate when thelid4 has been opened. Atab35 is integrally moulded with thebase3. Thetab35 is connected to thebase3 at two points: Afrangible connection36 and a non-frangible,deformable connection37. Atooth45 is provided on thelid4 in a suitable position to engage with thetab35. When thelid4 is closed for the first time, thetooth45 locks under thetab35 and thelid4 cannot be opened thereafter, without breaking thefrangible connection36. On first opening, as the lid is pivoted-upwards to its open position, the tooth45 (which is engaged under the tab35) pulls thetab35 upwards, thereby breaking thefrangible connection36. This upward movement also deforms the non-frangible connection37 (see FIG. 2). Therefore, after first opening, the raisedtab35 provides a visible indication that the container has been opened, even after thelid4 has subsequently been re-closed. Should a tamperer try to reinstate the tab in its original condition, the non-frangibleconnection37 will have permanently deformed and will still give a visible indication that the closure has been opened. Even if thenon-frangible connection37 can be pushed back to its original lowered position, the deformation will result in whitening of the material around theconnection37.