MOULDED CLOSURE FOR LIQUID CONTAINING PACKAGE

DESCRIPTION

This invention relates to the production of a partially completed container and of a package, to a package and to a container closure. According to a first aspect of the present invention, there is provided a closure for a container, said closure being of moulded plastics and comprising an openable pouring arrangement and a peripheral frame, said peripheral frame comprising a groove for receiving a container body end rim, said groove having respective opposite side walls and a base wall and serving to receive said rim between said side walls. According to a second aspect of the present invention, there is provided a method of producing a partially completed container, comprising providing on a mandrel a container sleeve open at both ends, bringing into proximity with each other an annular rim of one end of said container sleeve and a closure for said one end such that a skirt of a peripheral frame of said closure is disposed radially outwardly of said rim, and sealing said peripheral frame to said rim.

According to a third aspect of the present invention, there is provided a method of producing a partially completed container comprising bringing into proximity with each other one end of a container sleeve of substantially constant cross-section throughout the sleeve and open at both ends and an openable closure for said one end, and sealingly applying said closure to said one end while said sleeve remains of said substantially constant cross-section throughout said sleeve.

According to a fourth aspect of the present invention, there is provided a method of producing a package comprising bringing into proximity with each other one end of a container sleeve open at both ends and an openable closure for said one end, sealingly applying said closure to said one end, filling said container sleeve from the other end of the sleeve, sealingly closing said other end of said container

sleeve, and, following said bringing of said one end and said closure into proximity with each other, for the remainder of said method substantially refraining from changing the cross-section of said one end.

According to a fifth aspect of the present invention, there is provided a package comprising a flowable-material-tight container, the top and bottom surfaces of said container being of first and second shape, respectively, such that the top surface thereof is not suitably shaped for stacking thereon of the bottom surface of an identical package, and a member locatable in a position above said top surface of said container, the top surface of said member being more suitably shaped for stacking thereon of the bottom surface of said identical package than is said top surface of said container.

Owing to the invention, it is possible to improve the flexibility of a packaging system, especially to make it possible to vary considerably the character of the tops of the containers whilst having bottoms thereof standardised. In particular, the closure, which preferably ultimately forms the top of the container, is advantageously applied before the container is filled. The container sleeve, with the top closure in place, may be filled while upside down, with the bottom portion of the container sleeve being closingly folded and sealed after filling, to form the completed package. In addition, it is possible in a simple manner to improve the stackability of packages. It is also possible to provide in a simple manner a closure of the container and including an openable pouring arrangement, and to seal the closure to the rim easily and reliably.

In order that the invention may be clearly and complete disclosed, reference will now be made, by way of example, to the accompanying drawings, in which:-

Figure 1 is a flowchart of a method of producing a package; Figure 2 is a top perspective view of a package with a partly opened closure;

Figure 3 is a top perspective view of the closure before opening;

Figure 4 is a top perspective view of the package, but with a modified version of the closure;

Figure 5 is a top perspective exploded view of another modified version of the closure, with an additional member, and Figure 6 is a bottom perspective view of a peripheral frame of any one of the closures of Figures 2 to 5.

In the flowchart of Figure 1 , the steps in a method of producing a package on a form, fill and seal machine are illustrated. The package produced comprises a container filled with a flowable substance, for example a liquid food such as milk or fruit juice. In the first step 10, a container sleeve is picked by the machine from a supply of sleeves. The sleeves have been formed of paperboard coated on both sides with thermoplastics. A roll of plastics-coated paperboard will have been cut into blanks, and each blank been scored ready for folding and then sealed down one edge to create a flat sleeve. The sleeve that has been picked is opened to be of rectangular cross-section

(which is substantially constant throughout its length) and is then received over a free end of a mandrel until the lagging end of the sleeve arrives at that free end, and at step 12, the sleeve and an openable closure of a desired character are assembled together on the mandrel to form a partially completed container. For this purpose, the closure is brought into proximity with the lagging end of the container sleeve (which at this point is open at both ends) and the openable closure is sealingly applied to the lagging end of the container sleeve. The closure is of plastics material and is sealed to the container sleeve by ultrasonic welding, using the mandrel as an anvil for the ultrasonic sealing device. The mandrel is preferably one of a plurality of mandrels arranged in the form of a spider indexing about a horizontal axis.

Following the assembly of the partially completed container on the mandrel, the partially completed container is stripped from the mandrel, which is now downwardly directed, and transferred to a filling station, where, at step 14, there takes place filling of the container sleeve from the other end of the sleeve, which is now its upper end. It will be understood that the openable closure is the ultimate top of the container, and the partially completed container is filled while upside down, with the flowable substance being introduced via the ultimate bottom of the container.

Once the partially completed container has been filled, it is transferred to a sealing station. During transfer, the partially completed container is maintained in its upside down condition, with the ultimate bottom of the container upwards. At the sealing station, the step 16 of sealingly closing the open end of the partially completed container is carried out. The container bottom is folded and sealed into a fin seal and, following this step 16, the package is righted and the fin seal is folded in to create a flat bottom (at step 18) on which the container can stand. The final step in the method is the step 20, when the package is exited from the machine, for onward transfer to, for example, a supermarket, where the package is sold.

During the forming, filling and sealing of the container, following the bringing together of the end of the container sleeve and the openable closure, for the remainder of the method, the cross-section of the container remains substantially unaltered. Therefore, once the closure has been fitted and sealed to the container sleeve, the machine refrains from changing the cross-section of the container sleeve, except, of course, at its leading end which is fin-sealed.

Figure 2 illustrates a package 22 that can be made by the method as described above. The Figure shows the sleeve 24, as it would be after it has been filled after bottom-sealing, and the openable closure 26 is shown in a partly open

configuration. The container sleeve 24 is of substantially rectangular horizontal cross- section.

The closure 26 is of moulded plastics and comprises an openable pouring arrangement 28 (in the form of a tear flap) and a peripheral frame 30. The peripheral frame 30 has a groove for receiving the end rim 32 of the container sleeve 24. A skirt 33 of the peripheral frame 30 of the closure 26 is disposed radially outwardly of the rim 32. The underside of the frame is discussed in more detail below, with reference to Figure 7.

The closure 26 has integrally moulded therewith a member 34 that is integrally hinged to the frame 30. When the closure 26 is supplied for sealing to the open sleeve 24, the flap 28 is in an untorn condition and the member 34 is in a folded condition covering the flap 28. The closure 26 and the member 34 may be so designed that the member 34 readily releasably clips to the closure 26 in the folded condition. When the consumer purchases the package, he accesses the contents of the container by folding back the member 34 and pulling on a ringpull 36 attached to one corner of the flap 28 to tear back the flap 28. The consumer is then able to pour the contents from the container 22 as desired. The flap 28 can be totally removed by the consumer, with the member 34 being folded back down to reseal the container 22. In Figure 2, the container 22 is filled with strawberry milkshake, but is suitable for many other liquid products, such as milk, or flowable powder, such as washing powder. Without the member 34, the openable closure 26 gives the problem that the top surface is not ideally suited for stacking, when an identical container is placed on top of the container 22. The member 34, when folded over to cover the closure 26, provides a flat surface on the top of the package, with the result that the packages can now be more reliably stacked, as the bottom of the container is substantially flat.

Figure 4 shows a second version of the openable closure. The method of forming the container 22 is identical to that of forming the container of Figure 2, except that a different closure 40 is fitted to the container sleeve 24. As can be seen in the Figure, the closure 40 is a screw cap fitment, which is provided as a unit to be fitted and sealed to the lagging end of the sleeve 24 when the sleeve is present on the mandrel of the form, fill, and seal machine. The method steps are carried out in turn as discussed in relation to Figure 1.

Figure 5 shows another manner of adapting to a situation where the top surface of the container 22 is not suitably shaped for having stacked thereon the bottom surface of an identical container. Here, the package includes a separate member 42 that is locatable in a position above the top surface of the container 22. The member 42 either forms part of the closure 40 so as to act as a snap cap or screw cap, or is releasably attached to the closure 40 in such a way as to be easily removable by a consumer before the consumer opens the container. The top surface of the member 42 is flat and thus more suitably shaped for stacking thereon of the bottom surface of an identical container than is the top surface of the container 22.

The frame 30 is shown from the underside in Figure 6. The closure for the container 22 is of moulded plastics and comprises a desired openable pouring arrangement (removed from this view for clarity purposes) and the peripheral frame 30. The peripheral frame 30 has a groove 44 that is for receiving the container sleeve end rim, which it receives during the forming of the container 22. The groove 44 has respective opposite side walls 46 and 48 and a base wall and serves to receive the rim of the container sleeve between the side walls 46 and 48. The groove is continuous around the frame 30 in order to receive the rim of the container sleeve. Curving inwardly and downwardly from the side walls 48 are a plurality of guides 50 distributed around the frame 30 and serving to promote alignment of the end rim of

the sleeve 24 with the groove 44 during application of the closure 26 to that rim. As an alternative, if so desired the plurality of guides 50 can be replaced by a single, ring- form guide of similar cross-section and concentric with the groove 44. The closure 26 is made so as to be stiffer than a conventional closed and sealed bottom of a liquid packaging carton, so that the container 22 has, while being filled, an open top which is less likely to be non-rectangular than the open top of such carton.

In order to achieve a good seal between the plastics material closure 26 and the walls of the container sleeve, glue (or possibly hot melt) can be provided in the groove 44 before the closure is supplied to the container sleeve that is on the mandrel. This glue will typically be softened plastics such as LDPE, which is also used in the plastics layers that are parts of the container walls. The closures are applied in a continuous process onto the container sleeves in turn as the spider rotates.

The plastics module on top of the container 22, which comprises the closure and the member, replaces the standard gable top or flat top that is used on cartons for milk and the like. Furthermore, the production of plastics-coated paperboard carton is simplified, because the provision of a through hole, or a partial depth cut, during conversion of a plastics-coated paperboard web into carton blanks, to provide a pouring hole, or potential pouring hole, is avoided and the closure applicator can be simpler than a pour spout fitment applicator used for mounting a pour spout fitment in a pouring hole from the interior of the carton. The resulting package, with the plastics module, is easily stackable, without the need for any dividers between the layers of packages when they are stacked upon each other. The square member provided on the screw cap fitment embodiment of the package ensures that even these containers are readily stackable, without the need for dividers between the layers of packages.

The extra member on the container ensures a flat surface at the top to bear the flat bottom of the package above.

A number of further advantages are achieved by replacing the gable or flat top of a carton, including simplification of the production of the container blanks. Less scoring on the blank is required, and the resulting blank can have straight edges at both ends, which in many instances will lead to the saving of material in the production of the blanks.

The form, fill, seal machine can be more flexible, in that it can be easily adapted to produce containers with top closures of differing characters. When changing from a run of containers with a top closure of a first character, such as the tearable flap of the container of Figure 2, to a run of those of a second character, such as the screw cap fitment of Figure 4, only minimal changes to the machine need to be made. This relates to the device that is supplying the plastics closures and members to the sleeves on the mandrels. It effectively means that the machine can be used to provide a container with a top portion chosen from a very wide range of possibilities, unlike current machines that either are dedicated to a top closure of a single character, or can apply only a very limited range of top closures of differing characters. Since a number of stations in the form, fill, seal machine are not required when compared to a standard machine, such as those relating to the breaking, folding and sealing of the gable or flat top, this results in a machine with fewer parts.