GB2435467A

GB2435467A - Closure and spout assembly combined with a foil membrane

Info

Publication number: GB2435467A
Application number: GB0603728A
Authority: GB
Inventors: Craig Mcdowell; Peter Michael Mcgeough
Original assignee: Bapco Closures Research Ltd
Current assignee: Bapco Closures Research Ltd
Priority date: 2006-02-24
Filing date: 2006-02-24
Publication date: 2007-08-29
Anticipated expiration: 2026-02-24
Also published as: NZ570430A; JP2009527422A; EP1989125A1; GB0603728D0; AU2007217151A1; WO2007096674A1; ZA200807026B; CN101389544B; BRPI0708270A2; GB2435467B; HK1127326A1; MX2008010818A; RU2008137729A; CN101389544A; US20090218346A1; CA2642684A1

Abstract

A closure (2) has an overcap (6) resealably engageable with a spout (4). A foil retainer (40) depends from a top wall (30) of the overcap (6). The foil retainer (40) has an edge (42) which touches and is welded to a foil (20) that is induction heat sealed across an opening (10) within the spout (4). When the overcap (6) is opened, a portion of the foil (20) enclosed by the wall (40) is torn out to open the closure. This eliminates the need for a separate ring pull to open the closure. The closure may be for an open end of a can, having means for engaging over the can end.

Description

Description

Closure

Technical field

[0001] The present invention relates to closures for foil-sealed containers.

[0002] Cartons and plastics containers for drinks and other liquids are frequently sealed by means of an induction heat sealed (IHS) foil that is bonded to a rim of a mouth of the container typically within a spout. The foil closes the mouth opening in order to provide a gas barrier.

[0003] By contrast to older style containers sealed with a peelable foil that can be provided with a tab so that the foil can be removed by a peeling action once the overcap has been removed to expose the foil, in the case of modern BAP closure designs it is normally necessary to initiate a tear in a bonded foil in order to gain access to the contents of the container. The foil may also have its border bonded between the rim and a portion of the spout as, for example in the applicant's own earlier application, GB 2377701 (SPRECKELSEN MCGEOUGH LTD) 22.01.2003 so that there is no access to the border of the foil for a peeling style of opening.

[0004] An example of an older style closure employing a peelable foil is described in EP 1266839 A (PORTOLA PACKAGING LTD) 18.12.2002. In this case a pull tab is provided for assisting the removal of the foil membrane.

Peelable IHS foils are thicker, may have more layers, and are heavier and therefore more expensive than tearable IHS foils.

Background art

[0005] It has been suggested in GB 2350105 A (SPRECKELSEN MCGEOUGH LTD) 22.11.2000 that a plate be sealed to and support the foil. The plate is mounted to the overcap so that it can swivel relative to the overcap during the opening process. The plate is provided primarily to support the foil to prevent it being ruptured by gas pressure when the closure is used with pressurised fluids. However, opening of the overcap also initiates a tear in the foil membrane and breaks the seal.

Disclosure of the invention

Technical problem [0006] The larger the mouth of the container, the more difficult it is to initiate a tear in the foil membrane. These issues have been discussed in GB 2404916 (SPRECKELSEN MCGEOUGH LTD) 16.02.2005 which teaches design improvements for the mounting of a supporting leg of a pull ring in order to reduce the pulling force required to initiate the tear.

Technical solution [0007] The present invention provides a closure comprising a spout defining an opening, a foil membrane closing the opening in the spout and having a border adapted to be induction heat sealed to a container, and an overcap engaged with the spout, characterised in that the overcap has a foil retaining formation terminating in an edge bonded to the foil to define a removable portion of the foil.

[0008] The same principle can be employed with a plastics closure for a can end which comprises an overcap without a separate spout. In this application the present invention provides a closure for an open end of a can, comprising a foil membrane for closing the open end and having a border adapted to be induction heat sealed to the can end, and an overcap having (a) means for engaging it over the can end, (b) a foil retaining formation terminating in an edge bonded to the foil, and (C) a section adapted to be torn from a remainder of the overcap carrying a least a part of the foil retaining formation.

[0009] The edge of the formation may be continuously or intermittently welded to the foil. The formation is preferably a depending wall having an edge with a radius of less than.3 mm, preferably.1 mm.

Advantageous effects [0010] In use, removal of the overcap brings with it the removable portion of the foil. This eliminates littering issues associated with removable ring pulls.

[0011] The spout and overcap for use in a closure in accordance with the invention can be moulded very simply as there are no complex ring pull structures requiring the use of separate retractable metal cores which increase the cycle time of the mould.

[0012] The energy needed to weld the edge to the foil is modest because the edge is so fine. This is in contrast to the energy absorbed to weld a plate 3/ to the foil as in GB 235015 A (SPRECKELSEN MCGEOUGH LTD) 22.11.2000.

[0013] In an embodiment of the closure in which the overcap is clipped in position and has a peak by means of which the user can lift the overcap, the formation preferably has a shape which converges to a tip aligned with the peak.

Brief description of the drawings

[0014] In order that the invention may be well understood, four embodiments thereof will now be described, by way of example only, with reference the accompanying diagrammatic drawings, in which: [0015] Figure 1 is a perspective view of the spout and overcap in an open condition showing two alternative designs for the edge of the formation; [0016] Figure 2 shows a plan view of the overcap and spout of Figure 1; [0017] Figure 3 shows a section on line 3-3 of Figure 2 [0018] Figure 4 shows a plan view the spout and overcap of Figures 1-3 after it has been assembled into a closed, foiled condition; [0019] Figure 5 shows a section on line 5-5 of Figure 4; [0020] Figure 6 shows a plan view of an overcap and spout in accordance with a second embodiment of the invention;

] Figure 6A and 6B shows plan views as in Figure 6 showing variations of the profile for the shape of the foil retainer; [0022] Figure 7 shows a perspective view of a closure for a can end in accordance with the third embodiment of the invention; [0023] Figure 8 shows a section through an edge of the overcap of Figure 7; [0024] Figure 9 shows a fourth embodiment of a closure for a can end; and [0025] Figure 10 shows a section through an edge of the overcap of Figure 9.

Mode(s) for carrying out the invention [0026] The present invention can be implemented as a spout and overcap combination or as an overcap only for use on an open can end. The spout and overcap embodiments will first be described with reference to Figures I to 6.

[0027] A closure 2 for fitting to a container (not shown) consists of a spout 4 connected to a flip-top overcap 6 by a hinge 8. The spout 4 has a cylindrical wall portion 12 defining an opening 10 and a base 14. The cylindrical wall portion 12 terminates in a pour lip 16. A sealing rib 18 is formed around an inner surface of the side wall 12 in order to seal against a valve in the overcap 6. A series of foil tearing teeth 19 are formed around the opening 10.

[0028] A foil membrane 20 is sealed across the opening 10 in the spout 4. A border 22 of the foil membrane 20 is welded by induction heat sealing to the base 14 of the spout. The foil membrane 20 is a double sided foil, which is a thin aluminium foil coated on one side with a plastics material compatible with the material from which the spout and overcap are moulded and on the other side with a plastics material compatible with the material of the container. The membrane 20 may also be or contain a plastics barrier membrane. For example the membrane may be a laminate that contains a plastics barrier layer.

[0029] The structure of the spout 4 is otherwise as described in the applicant's own earlier application GB 2377701 A (SPRECKELSEN MCGEOUGH LTD) 22.01.2003 and BAP closures manufactured in accordance with designs based on that technology, except for the significant omission of a removable portion that is typically moulded across the opening 10 in the spout. Such a removable portion with its associated ring pull adds considerably to the cost and expense of the spout mould or spout portion of a hinged mould. The remaining details of the spout construction will not therefore be described further as they will be familiar to the skilled reader.

[0030] The overcap 6 is also substantially as described in that earlier specification. The overcap has a top wall 30, a side wall 32 and a peak 34 opposite the hinge 8. A cylindrical valve 36 depends from the inside of the top wall 30 and is positioned so that its outer surface will engage with and seal against the sealing rib 18 inside the side wall 12 of the spout 4. The overcap of the present invention however differs in that there is an additional foil retaining formation, in this case a cylindrical wall 40 that acts as a foil retainer. The foil retainer 40 depends from the top wall 30 of the overcap 6 inside the valve 36. The foil retainer 40 terminates in an edge 42 that is formed with a fine radius of.3 mm or less preferably.1 mm. The 5.

thickness of the wall 40 tapers towards the edge 42. The height of the foil retainer 40 is such that the edge 42 will just touch an upper surface of the foil membrane 20 when the overcap 6 is closed over the spout 4. When the edge 42 is in contact with the foil 20, it will define and enclose a circular portion of the foil membrane 20.

[0031] The edge 42 may be continuous as shown in the major portion of the edge 42 in Figure 1. The edge 42 may also be crenellated as illustrated at 44.

The edge is therefore discontinuous with short sections 46 separated by cut-outs 48. Only the sections 46 of the edge will weld to the foil membrane 20. It will be appreciated that the shapes of the cut-outs 48 are to be designed to facilitate moulding and tearing.

[0032] The foil membrane may be weakened in the region of the edge 42 to facilitate tearing. This weakening can be created by a laser process. It is preferable to avoid this step but it may be necessary for thicker foils or where the edge 42 cannot be moulded sufficiently fine.

[0033] An arrowhead 50 is moulded as a depression in a flat top surface of the top wall 30 in order to point to a centre of the peak 34. This arrowhead directs the consumer to the peak in order to indicate the point at which the closure should be opened. Forming the arrowhead as a depression facilitates use of the closure by blind or partially sighted consumers.

[0034] A breakable tab (not shown) may be formed between an edge of the overcap and the spout to facilitate visual tamper evidence. Such a breakable tab must be removed before the overcap can be lifted. Other standard forms of tamper evidence such as a band or strip around the overcap may be adapted for use with this closure.

Second Embodiment [0035] Figure 6 shows an alternative embodiment of the foil retainer 40 but is otherwise identical to the previously described embodiment. As shown in Figure 6, the formation 40 is not a cylindrical wall but is shaped to converge to a narrower tip 52 aligned with the centre of the peak 34.

[0036] Other variations for the shape of the formation are shown in Figures 6A and 6B. In these designs the formation 40 has a shape which defines tips 52' spaced to either side of the peak 34. . These designs have been found to be more effective in tearing out the enclosed portion of foil with minimal effort.

Method of Assembly and Use [0037] It will be appreciated that the spout and overcap described can be moulded readily in one piece with a mould that forms the spout and overcap together in an open condition as shown in Figure 1. The closure 2 is assembled by pivoting the overcap 6 about the hinge 8 so that the valve 36 is engaged inside the spout 4. In this closed condition as shown in Figure 5, a foil membrane 20 is placed in the base 14 of the spout and induction heat sealed to the spout. The induction heat sealing process will weld the foil to the areas of plastics material that it is touching when the placing pressure is applied. Therefore, the border 22 of the foil will weld to a horizontal surface of the base. The edge 42 or those spaced portions of it 46 which touch the foil 20 will also weld to it. Limiting the area of contact between the foil and the plastics of the spout 4 and edge 42 reduces the amount of energy used to weld the foil and reduces the effort to tear it later.

[0038] As with earlier BAP closures, the closures 2 can be sterilised in the closed, foiled condition and supplied to a factory where they will be fitted to containers.

[0039] When a container that has been closed with a closure as described is received by the consumer, it can be opened by the application of a lifting force applied to the peak 34 of the overcap at the position indicated by the arrow 50. On first opening the closure, there will be a degree of resistance as the foil 20 is lifted and stretched by the formation 40. This lifting force will eventually tear the foil adjacent the edge 42. As the foil is ruptured, there will be an audible pop. This provides consumer reassurance that the closure has not been tampered with.

[0040] When the overcap 6 is pivoted fully open, the space within the foil retainer will normally be covered by the enclosed portion of the foil which has been removed during the opening process. The foil may also be torn by the teeth 19 at the edge of the opening 10.

[0041] In the embodiment of Figure 6, the lifting force applied by the user to the peak 34, initially creates a tear at the tip 52 at which the force is concentrated. The tear will then propagate in both directions around the edge 42 resulting in a droplet shaped enclosed portion of foil being removed with the overcap. A similar effect will be produced using the profiles of Figures 6A and 6B. Shaping the edge 42 in one of these ways is particularly desirable in applications with larger closures and thicker foils.

[0042] In most cases, it will be possible to dispense the contents of the container through the opening created by removal only of the portion of the foil 20 that is enclosed by the edge 42. However, the remaining region of the foil (if any) across the opening 10 may be pushed into the container to clear the entire opening 10.

[0043] Since the removed portions of the foil 20 are retained in the closure, littering issues are eliminated.

[0044] It will be appreciated that the exact tearing propagation will depend on the force applied during the opening process and the utility of the closure as described is not dependent on any particular tearing pattern.

[0045] The closure can be resealed by the consumer as with the existing BAP closures. Different shapes and designs of the overcap can readily be implemented for brand differentiation purposes. The construction of the present invention therefore retains all the consumer attributes of the earlier closures but allows a simpler mould and a lighter weight closure. The invention therefore makes a closure that is suitable for applications which are of greater price sensitivity.

Can End Embodiments [0046] Figures 7 to 9 relate to an implementation of the invention in which a single piece moulded closure 60 (as opposed to a two piece moulded or hinged unit) is designed to replace the whole of an end of a cylindrical can 61, for example a drinks can or bottle made of thermoformed plastics material. The can is essentially cup shaped and has an opening which is closed by the closure 60. 8/

[0047] The closure 60 comprises an overcap 62 having a flat top 64 and a depending skirt 66, and a foil membrane disc 68 held inside the overcap by means of a foil retaining formation 70 in the form of an annular ridge or land that is formed on an inner surface of the top 64. The foil retainer 70 terminates in an edge 72 that is bonded to the foil 68.

[0048] An edge of the skirt 66 has a bead 74 formed around its internal surface in order to provide means by which the overcap can be engaged over the can end to hold it in position during assembly. The closure 60 is sealed to the can end by induction heat sealing of a border of the foil 68 to a rim of the can.

[0049] The overcap 62 also has a section 80 that is adapted to be torn from a remainder of the overcap to create a drinking or pouring opening. The section 80 carries an arcuate section 82 of the foil retaining formation 70.

The section 80 is separated from the remainder of the overcap by tear lines 84 along each side. These tear lines 84 are thinner plastics webs. A hinge 86 is formed in the overcap at a back of the removable section 80 nearest the centre of the top 64. A peak 88 can be moulded at the front edge of the section 80 to facilitate lifting of the section. A tab 90 is formed so that it projects outwardly from the remainder of the skirt 66 sO it can be grasped to initiate the tearing of off of the section 80 and subsequent opening by pivoting the section 80 about the hinge 86. When the section is opened in this way, the foil will be torn as it is lifted by the section 82 of the foil retaining formation 70.

[0050] The tab 90 can be clipped right over out of the way of the user's mouth by clipping it over the edge of the skirt 66 opposite the opening. After opening, the can can be closed by bringing the section 80 back over the opening.

[0051] An alternative style of can end closure is illustrated in Figures 9 and 10.

Like reference numerals are used for similar parts. In this embodiment the overcap 62 does not have a continuous upper surface but exposes parts of the foil membrane 68. A portion 94 of the upper surface of the overcap 62 is moulded in such a manner that it can be removed by gripping on a pull tab 96. In this embodiment the foil retainer is a wall formation 98 underneath the portion 94 indicated by dotted lines. This formation 98 does not need to be a closed circle as shown in previous embodiments.

There may also be more than one foil retainer edge. This type of can end can be adapted for various types of spout construction.

[0052] It will be appreciated that given the concept of a foil retainer with an edge welded to the foil membrane on a part of an overcap that is removed during the opening process, the skilled man will be able to design various patterns and configurations for such edges that facilitate tearing and lifting of the required parts of the foil needed to leave a convenient drinking opening. The removed parts of the foil held by the foil retainer edges can also be designed to have aesthetic shapes.

Variations [0053] The closure as illustrated in Figures 1 to 6 is intended for use with a 33mm bottleneck but it will be appreciated that it can be used for wide mouthed bottles and smaller drinks bottles as well as adapted for wide mouthed jars, cartons, cans and thermoformed containers of all manner of diameters.

[0054] Additional tamper evidence can be provided by a removable or breakable tab adjacent the peak 34 locking the overcap to the adjacent wall of the base. In the can end embodiment, a similar breakable tab or other tamper evidence structure may be provided. The can end embodiments can also be used on a variety of can diameters.

[0055] Moulding the overcap 6 or 62 out of a see through or clear or clarified plastics material also offers additional visual tamper evidence.

[0056] It is therefore possible to provide feedback by visual, audible and touch mechanisms to reassure consumers that the products supplied with the closure has not been previously opened or tampered with.

Claims

1o --Claims 1. A closure comprising a spout defining an opening, a foil

membrane closing the opening in the spout and having a border adapted to be induction heat sealed to a container, and an overcap engaged with the spout, characterised in that the overcap has a foil retaining formation terminating in an edge bonded to the foil to define a removable portion of the foil.

2. A closure for an open end of a can, comprising a foil membrane for closing the open end and having a border adapted to be induction heat sealed to the can end, and an overcap having (a) means for engaging it over the can end, (b) a foil retaining formation terminating in an edge bonded to the foil, and (c) a section adapted to be torn from a remainder of the overcap carrying a least a part of the foil retaining formation.

3. A closure as claimed in claim I or 2, wherein the edge of the formation is continuously welded to the foil.

4. A closure as claimed in any one of the preceding claims, wherein the edge is intermittently welded to the foil.

5. A closure as claimed in any one of the preceding claims, wherein the edge is crenellated.

6. A closure as claimed in any one of the preceding claims wherein the edge has a radius of less than.3 mm 7. A closure as claimed in any one of the preceding claims wherein the edge has a radius of.1 mm or less.

8. A closure as claimed in claim I, wherein the overcap has a peak by means of which the user can lift the overcap, the formation having a shape which converges to a tip aligned with the peak.

9. A closure as claimed in claim 1, wherein the overcap has a peak by means of which the user can lift the overcap, the formation having a shape which defines tips spaced to either side of the peak.

10. A closure as claimed in any one of the preceding claims, wherein the overcap has a depending valve for sealing engagement with the spout.

11. A closure as claimed in claim 10, wherein the depending valve is the formation.

12. A closure as claimed in claim 10, wherein the formation is formed inside the depending valve. 11/

13. A closure as claimed in any one of the preceding claims, wherein the overcap is made from a see through or clear or clarified plastics material.

14. A closure as claimed in any one of the preceding claims, wherein the overcap is attached to a container or spout by means of a breakable tab.

15. A closure substantially as herein described with reference to Figures 1 to 5, Figure 6, or Figures 7 and 8 of the accompanying drawings.

Amendments to the claims have been tiled as follows: Claims 1. A closure (4, 6; 60) comprising a spout (4) defining an opening (10) and a foil membrane (20; 68) closing the opening (10), the closure (4, 6; 60) having an openable section (6; 80) with a foil retaining formation (40; 70; 98) terminating in an edge (42; 72) bonded to the foil to define a removable portion of the foil membrane (20; 68), the foil membrane (20; 68) also being bonded to a non-openable section (14; 62) of the closure (4, 6; 60) before application to a container; characterised in that the closure has means (14; 66) for engaging it over an open end of a container; in that the foil membrane (20; 68) is held inside the closure (4, 6; 60) in order to provide a border adapted to be induction heat sealed to the container; and in that the openable section (6;

80) is pivotable relative to the non-openable section (14; 62) of the closure.

2. A closure as claimed in claim 1, wherein the openable section is an overcap (6) 3. A closure as claimed in claim 1, wherein the openable section (80) is adapted to be torn from a remainder of an overcap (60) carrying a least a part of the foil retaining formation (70). *4*

4. A closure as claimed in any one of the preceding claims, wherein the edge of the formation is continuously welded to the foil.

5. A closure as claimed in any one of claims I to 3, wherein the edge is intermittently welded to the foil.

6. A closure as claimed in claim 5, wherein the edge is crenellated.

7. A closure as claimed in any one of the preceding claims, wherein the edge has a radius of less than.3 mm 8. A closure as claimed in any one of the preceding claims, wherein the edge has a radius of.1 mm or less.

9. A closure as claimed in any one of the preceding claims, wherein the openable section has a peak by means of which the user can pivot it, the formation having a shape which converges to a tip aligned with the peak.

10. A closure as claimed in any one of claims 1 to 8, wherein the openable section has a peak by means of which the user can pivot it, the formation having a shape which defines tips spaced to either side of the peak.

11. A closure as claimed in any one of the preceding claims, made from a see through or clear or clarified plastics material.

12. A closure as claimed in any one of the preceding claims, wherein the overcap is attached to a container or spout by means of a breakable tab.

13. A closure substantially as herein described with reference to Figures 1 to 5, Figure 6, or Figures 7 and 8 of the accompanying drawings.

S