AU2004202664A1

AU2004202664A1 - Hinged lid container

Info

Publication number: AU2004202664A1
Application number: AU2004202664A
Authority: AU
Inventors: Paul Daffurn; Ian Janetski
Original assignee: Huhtamaki Australia Pty Ltd
Current assignee: Huhtamaki Australia Pty Ltd
Priority date: 2003-12-15
Filing date: 2004-06-17
Publication date: 2005-06-30
Also published as: EP1720772A4; AU2004296894A1; NZ585281A; AU2010214759B2; AU2010214759A1; WO2005056414A1; ZA200605811B; AU2004296894B2; NZ587724A; EP1720772A1

Description

P001 Section 29 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: HINGED LID CONTAINER The following statement is a full description of this invention, including the best method of performing it known to us: HINGED LID CONTAINER FIELD OF THE INVENTION The present invention is directed to containers for foodstuffs such as icecream, margarine and so on, and in particular to containers including a base having a top opening and a lid secured on the base and extending across the top opening.

BACKGROUND OF THE INVENTION Containers of the abovenoted type typically have a snap fittingly reengageable arrangement between the lid and the base to facilitate removal and reengagement of the lid over the top opening of the base. This arrangement ensures that the lid is securely held in place to the base. This type of container design is particularly appropriate when the lid needs to be made of a different material or colour than the base. It is however, advantageous at times to have the lid at all times attached to the rest of the container to prevent the misplacing of the lid or possible contamination by foreign material if the lid is separated from the base. To this end, it is known to provide containers having a lid hinged to the base. These containers are typically formed in one piece and then folded along the hinged line to provide the final closed container. The engagement of the lid and base of such one piece containers are however not always particularly secure or airtight. Furthermore, the tooling cost for one piece containers can be higher. In addition, it is not possible to use different materials or colours for the lid and the base.

One solution is to provide a hinge by welding a peripheral shirt of the lid to a peripheral skirt of the base. A crease is provided in the peripheral skirt of the lid to act as a hinge line for the lid. Such an arrangement is described in International Application No. PCT/BR97/00030. This allows the lid to be pivoted away from the top opening of the base about the hinge line while still remaining secured to the base. Another possible solution is to provide a hinge line within the lid itself. This may be achieved by providing a hinge line that extends across the lid with a hinge portion and a lid portion being provided on opposing sides of the hinge line. This hinge portion of the lid may then be fixedly secured to the base so that the lid portion can be rotated about the hinge line while the hinge portion remains secured to the base. This then also allows access into the container while at the same time allowing the lid to be partially secured to base of the container.

The problem with both these arrangements is that there is a tendency for the container to break along the hinge line after repeated flexing about that hinge line. This is because the types of plastic material typically used in the manufacture of foodstuff containers do tend to weaken after such repeated flexing. With components made of plastic material such as polypropylene, the area of the component that needs to be regularly flexed can be strengthened by flexing the component while the material is still warm immediately after the injection moulding of the component. This acts to align the polymer chains within the flexed area strengthening this area for repeated flexing. It is not however always possible or convenient to pre-flex the components in this way during the manufacture of the components.

Another problem associated with the above noted containers is that it is not always possible to provide tamper evident means for the container. This is particularly important for containers used in the sale of food products where such tamper evidence provides added comfort to purchases of this product that the contents of the container have not been tampered with. It is therefore an object of the present invention to overcome at least one of the above noted disadvantages.

SUMMARY OF THE INVENTION With this in mind, according to one aspect of the present invention, there is provided a lid for a container including a base havinrg a top opening, the lid being securable on the base and extendible across the top opening, the lid including a hinge line, and a flexible membrane applied to and extending at least substantially over the hinge line of the lid, the membrane being formed of a material having an initially orientated internal structure to thereby support repeated flexure of the lid about the hinge line.

The hinge line may be provided by a web-type hinge integrally formed in a central web of the lid. Alternatively, the hinge line may be provided by a groove extending across the central web.

The lids for containers according to the present invention are typically made from plastic material such as polypropylene. As previously noted, the problem with such material is that repeated flexing of this material along a line can result in breakage or fracture along that line. This is due to the un-orientated polymer chain internal structure of the internal material. The membrane according to the present invention can also be made of a plastic material such a polypropylene. However, the membrane will have an initially orientated internal structure which is more resistant to damage by repeated flexure of the material. In the lid according to the present invention, the provision of the membrane provides support along the hinge line of the lid thereby allowing for the repeated flexure along that hinge line.

The membrane may be applied to an injection moulded lid by locating the membrane within the mould for the lid. Subsequent injection moulding of the lid results in the membrane becoming integrally secured to the injection moulded lid.

This manufacturing method is known in the art for incorporating labels on lids and is known as "in-mould labelling". The membrane may in fact be in the form of a label as well as providing the additional benefit of supporting the lid along the hinge line.

The provision of the membrane over the hinge line of the lid therefore acts to reinforce the hinge line area of the lid thereby allowing for repeated flexure.

This therefore enables the lid to be used as a hinged closure for the container.

According to another aspect of the present invention, there is provided a container including a base having a top opening and a lid as described above secured on said base and extending across said top opening.

The lid may include a hinge portion secured to the base; and a lid portion is secured to said base by frangible or deformable securing means, the hinge portion and lid portion being located on opposing sides of the hinge line.

The container my be initially openable by breakage or deformation of said securing means on one side of said hinge line and rotation of said lid portion about said hinge line; The breakage or deformation of said securing means in initial opening of said container is subsequently evident to a user of said container. This provides a tamper evidence arrangement from the container.

Preferably, said securing means includes a part of one of said lid portion and said base that is attached to the other of the said lid portion and said base and that is detached from said one and remains attached to said other upon rotation by a user of said lid portion in initial opening of said container. Said part of said one of said lid portion and said base may in particular be welded to said other of said lid portion and said base. Where the container is formed from plastics materials, welding may for example be carried out by the known technique of ultrasonic welding, or by thermal means, by adhesive. However, other types of securing means may also be provided, as disclosed below.

Said part may be at least partially surrounded by a region of reduced strength of said one of said lid portion and said base whereby to control the force required to detach said part. This approach may be also delimit a zone of breakage or deformation and so prevent excessive damage to the container during opening.

Said region of reduced strength may include at least one perforation. One or more lines of reduced thickness may also or alternatively be included in the said region.

Said hinge line may be a web-type hinge formed integrally with a central web of said lid. This is advantageous when the container is formed wholly or partly of plastics materials which lend themselves to the provision of web-type hinges. Alternatively, the hinge line may be a groove extending across the central web of the lid.

Preferably, said lid portion is snap-fittingly re-engageable with said base after initial opening whereby to close said container.

Said hinge portion may be secured to said base by welding, for example of the types mentioned above. This arrangement can be advantageous for example in applications such as lidded tub-type containers for ice cream and like products, where tooling costs for one piece containers may be higher and/or where it may be desired to use different material for the base and lid.

Conveniently for production, both the hinge portion and lid portion of the lid may be secured to the base by welding. In this case, the strength of the attachments of the hinge and lid portions to the base may be made different to ensure that the intended lid portions to the base may be made different to ensure that the intended lid portion is the one actually opened by a user. It is preferred that the lid has a peripheral rim formation engageable with a cooperating peripheral rim formation extending around said top opening of said base, and particularly preferred that the rim formations of said lid and said base part are snap fittingly engageable with each other. Suitable cooperating rim formations can enhance security against tampering, by preventing access to the container, without damage to the frangible or deformable securing means, through insertion of a thin object into a gap between lid and base. Snap fitting also gives some certainty of correct closure to a user.

It will be convenient to describe a preferred embodiment of the present invention with respect to the accompanying drawing. It is however to be appreciated that other embodiments are possible, and consequently the particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description of the invention.

Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material formed part of the prior art base or the common general knowledge in the relevant art in Australia on or before the priority date of the claims therein.

BRIEF DESCRIPTION OF THE DRAWINGS: In the drawings: Figure 1 is a perspective view of a container having a lid according to the present invention; Figure 2 is a perspective view of the base of the container of Figure 1; and Figure 3 is a perspective view of the underside of the lid of the container of Figure 1.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the Figures there is shown a base-and-lid container according to the invention. The container is of a type suitable for the sale and storage of icecream for domestic use. However, in no sense is the invention limited to containers for this application.

The container consists of two parts, namely a open-topped base 1 and a lid 3. The base has a floor 5 and four upstanding sidewalls 7 whose upper edges define a rim formation 9.

The lid 3 has a central web 11 and a peripheral rim formation 13. The rim formation 9 of the base 1 includes a horizontal flange 15 extending outwardly from an upper edge of the sidewalls 7 and the skirt 17 depending from an outer edge of the flange 15. The rim formation 9 extends around the entire periphery of the base. The rim formation 13 of the lid 3 includes a skirt 16 depending from an outer edge of the web 11. Extending inwardly from this skirt 16 is a bead 18 which lies below the depending skirt 17 of the rim formation 9 of the base 1, so that the lid 3 fits snap fittingly on the base 1. Extending across the central web 11 of the lid on its lower side is a line of reduced thickness forming, in effect, a web-type hinge 2. This web-type hinge 2 divides the lid into two portions, a hinge portion 21 on one side of the hinge 2 and a lid portion 23 on the other.

The lid 3 is typically made of a plastic material such as polypropylene in an injection moulding process. During the manufacturing process, a flexible membrane is placed into the mould cavity for the lid. During the subsequent injection moulding of the lid, the membrane becomes at least substantially integrated with the lid 3 and cannot be therefore shown in the drawings. This membrane can be made of a plastic material having an initially oriented internal structure. The plastic material can also be polypropylene. This membrane is secured over the hinge line 2 and acts to support the lid for repeated flexure along the hinge line 2. this enables the lid portion 23 of the lid 3 to be repeatedly rotated away from the base 1 to allow access therein.

In use of the container by a food manufacturer, the base 1 is first filled with the product to be contained. The lid 3 is then snap fittingly engaged with the base 1, extending across the top opening 8. when the lid 3 is in place on the base 1, a lower face of the central web 11 abuts an upper face of the flange 15 of the rim formation 9 of the base 1. Next, the lid 3 is welded in place on the base 1. this is done at four points, of which two points 10 are on the hinge portion 21 of the lid 3 and the remaining two points 12 are on the lid portion 23 of the lid 3. The welds on the hinge portion 21 of the lid are made in known fashion by ultrasonic means.

Specifically, upper and lower platens (not shown) are placed against an upper surface of the web 11 and a lower surface of the flange 15 of the base 1, the upper platen being in line with the lower platen. By application of ultrasonic vibrations to one or both the platens welding by localised melting is obtained. The result is spot-welding of the lid 3 to the base 1: The two welds 12 on the lid portion 23 of the lid 3 are made in essentially the same manner by ultrasonic means. However, in addition, the welds 12 on the lid portion 23 of the lid 3 are surrounded by a line of perforations 25 extending through the web 11 of the lid 3. The effect of the perforations 25 is that when a user separates the lid 3 from the base 1 at the location of the welds 12 on the lid portion 23 of the lid 3, a disc-shaped piece of the web 11 remains welded to the flange 15 of the base 1 while the remainder of the lid 3 is detached from the base 1. Webs between the individual perforations are broken during opening in this manner.

The depending skirt 16 of the lid 3 extends around the entire periphery.

The skirt 16 is at the outermost extremity of the lid 3. It follows that any attempt to rotate the lid portion 23 of the lid 3 relative to the hinge portion 21 of the lid 3 about the hinge line 3, before placement of the lid on the base 1, will be resisted by compression or extension of the depending skirt 16 of the lid adjacent to the hinge line 2 prior to placement of the lid on the base. This is advantageous in that the lid 3 behaves as a substantially rigid single item.

However, after placement of the lid 3 on the base 1 and welding of a lid to the base, such resistance is undesirable, as it renders difficult the rotation of the lid portion 23 of the lid relative to the hinge portion 21 when opening of the container is underway. Therefore, the depending skirt 16 of the rim formation 13 of the lid is provided with a reduced thickness section 31 at each end of the hinge line 2. When the lid has been welded to the container by welds, it can subsequently be opened by a user applying an upward force to and edge 33 of the lid which is parallel to the hinge line 2. the effect is to break the welds 12 leaving discs 35 welded to the flange 15 of the rim formation 9 of the base 1, and to deform or break the sections of the lid rim formation 31 adjacent to the ends of the hinge line 2. Once the lid portion 23 of the lid 3 is rotated a sufficient distance around the hinge line 2, the contents of the base 1 can be accessed and removed.

Once a desired quantity of the contents of the container has been removed, the lid may be re-closed by rotating the lid portion 23 of the lid about the hinge line 2 until it is again in contact with the rim formation 9 of the base. In the last part of this rotation, the lid portion 23 of the lid snap fittingly re-engages with the rim formation 9 of the base.

The container is tamper evident, in that once first opened in the manner described above, the fact that its having been opened is readily apparent from the discs 35 being broken from the lid and remaining attached to the flange 15 of the base, and also by virtue of deformation of fracture of the regions 31 of the skirt of the rim formation 16 of the lid. The first of these effects in practice is the more important of the two. A user will also notice when opening the container on second and subsequent occasions that the resistance provided by breaking of the welds 12 is no longer present.

Of course, it is possible to remove the lid completely by prising both the hinge and lid portions 21,23 off the base. The welds 10 holding the hinge portion 21 of the lid in place on the base may be made weak enough for this to be a practical step, but stronger than the welds 12 on the lid portion. It will be noted that the ability to remove the lid entirely is advantageous where the lid and base are of different materials with different recycling requirements.

The lid and base are particularly well suited to manufacture by injection moulding using plastics.

To increase the rigidity of the lid, it is provided with grooves 37 inwardly of an extending parallel to the four sides of lid. At the centre of edge 33 of the lid skirt 16, the skirt is slightly recessed and a lip at the base of the skirt is correspondingly slightly wider than elsewhere along that edge, to facilitate a user gripping it for the purpose of opening the container. The word '"LIFT" is embossed on the lid to show the consumer what to do. The grooves 37, by stiffening the lifting edge 33 of the lid, makes it possible to break the welds 12 by lifting at the centre of edge 33, but also reduces the possibility of the lid 3 separating from the base along that edge.

A container made in this way is advantageous for manufacturers and users. Both lid and base can be manufactured in conventional fashion and handled in conventional fashion prior to placement of the lid on the base after filling. However, after filling and sale to the consumer, the consumer has the convenience of a rotating lid that can be resealed positively and the confidence in the safety and security of the contents that comes from the provision of a tamper evident capability.

It will be noted that the four welds can be made in a single operation if required with the ultrasonically excited platens being moved in a vertical direction towards each other. The line of perforations can be made, if required, by suitable shaping of the upper platen that produces the weld in question.

Steps known in the art may be taken to provide for nestability of the lids and bases prior to joining. As can be seen in Figure 3 the depending skirt of the rim formation of the lid, and its integrally formed bead, can provide for stacking without the lids in a stack being difficult to separate. It is also known to provide nesting formations on bases of containers of the present type. These are not shown in the diagrams, but are known in the art.

In the preferred embodiment, the lid and base are welded together by ultrasonic means. However, it is known in the art to weld suitable materials together by other means. These include straightforward welding by heat and the use of adhesives and solvent welding.

The use of other means of providing tamper evident connections between the parts are also envisaged.

Many changes and variations may be made to containers such as those described without departing from the spirit and scope of the invention as defined in the appending claims.

Claims

1. A lid for a container including a base having a top opening, the lid being securable on the base and extendible across the top opening, the lid including a hinge line, and a flexible membrane applied to and extending at least substantially over the hinge line of the lid, the membrane being formed of a material having an initially orientated internal structure to thereby support repeated flexure of the lid about the hinge line.

2. A lid according to claim 1, wherein the hinge line is provided by a web-type hinge integrally formed in a central web of the lid.

3. A lid according to claim 1, wherein the hinge line is provided by a groove extending across the central web.

4. A container including a base having a top opening, and a lid according to claim 1 securable to the base and extendible across the top opening.

A container according to claim 4, wherein the hinge line is provided by a web-type hinge integrally formed in a central web of the lid.

6. A container according to claim 4, wherein the hinge line is provided by a groove extending across the central web.

7. A container according to any one of claims 4 to 6, wherein the lid includes a hinge portion secured to the base; and a lid portion is secured to said base by frangible or deformable securing means, the hinge portion and lid portion being located on opposing sides of the hinge line.

8. A container according to claim 7, wherein said securing means includes a part of one of said lid portion and said base'that is attached to the other of the said lid portion and said base and that is detached from said one and remains attached to said other upon rotation by a user of said lid portion in initial opening of said container.

9. A container according to claim 8, wherein said part is at least partially surrounded by a region of reduced strength of said one of said lid portion and said base whereby to control the force required to detach said part.

A container according to claim 9 wherein said region of reduced strength includes at least one perforation.

11. A container according to claim 9 or 10 wherein said region of reduced strength includes one or more lines of reduced thickness.

12. A container substantially as hereinbefore described with reference to any one of the embodiments shown in the accompanying Figures 1 to 3.

13. A lid substantially as hereinbefore described, with reference to any one of the embodiments shown in the accompanying Figures 1 and 3. DATED this 15 TH day of June 2004 HUHTAMAKI AUSTRALIA LIMITED WATERMARK PATENT TRADE MARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA P23426AUP1