WO2023183966A1

WO2023183966A1 - Bottle closure, system, and related method

Info

Publication number: WO2023183966A1
Application number: PCT/AU2023/050220
Authority: WO
Inventors: Anthony Arduca; Robert ARDUCA; Andrew Peter ARDUCA; Steven FANTIN
Original assignee: Interpack Pty Ltd
Priority date: 2022-03-28
Filing date: 2023-03-27
Publication date: 2023-10-05

Abstract

Disclosed herein is a bottle closure comprising a body with an open end and a closed end, and a fracture initiator configured to propagate a crack in the closure body from the open end toward the closed end on application of a critical applied stress.

Description

BOTTLE CLOSURE, SYSTEM, AND RELATED METHOD

Field

[0001] The invention relates to a bottle closure, in particular for wine or beer bottles, a related method of use and production, and a tool for use in fabricating such a bottle closure.

Background

[0002] The invention generally relates to a bottle closure, and in particular wine or beer bottle closures.

[0003] Bottle closures are commonly manufactured using a deep drawing process where a metal blank is drawn into shape with a pommel. Whilst this process is an economical method of mass- producing bottle closures, it has a number of drawbacks.

[0004] One issue is that the resultant bottle closure has varying thickness, with the bottle closure being thicker towards the bottom as the metal blank is drawn through the die. One method of addressing this issue is to provide a blank with excess metal to account for this increase in thickness. However, this approach adds to the overall cost of the process. Another issue that arises in situations where a coating is applied to the blank (e.g. an ornamental coating may be applied to a surface of the blank that forms the exterior surface of the bottle closure, or a functional coating may be applied to a surface of the blank that forms an internal surface of the bottle closure), is that the coating can be damaged during the drawing process. This is can have a deleterious effect on both visual appearance and/or on the performance of the coating.

[0005] Figure 1 is an illustration of a typical metal wine bottle closure 100 after extrusion and before subsequent shaping and application of the bottle closure 100 to a bottle. The bottle closure 100 includes an end cap portion 102 and a skirt portion 104.

[0006] To apply, the closure 100 is fitted over the mouth and neck of a wine bottle such that the end cap portion 102 rests against the mouth of the bottle and the skirt portion 104 extends downward over the neck of the bottle. A specialised machine then seals the closure 100 to the bottle. This process results in the formation of at least a threaded end cap, a frangible portion between the end cap portion 102 and the skirt portion 104, and a tuck-under which provides tamper evidence security.

[0007] A typical wine bottle with closure applied thereto is illustrated in Figure 2. The bottle closure 200 generally includes: a threaded end cap 202 which seals over the open end of a bottle 203, a skirt 204 extends downward from an open end of bottle 203 over a neck of bottle 203, a tuck-under 206 retains at least the skirt 204 on bottle 203 to provide tamper evidence, a support bead 208 that supports the tuck-under 206, and a frangible portion 210 between end cap 202 and skirt 204. Frangible portion 210 allows a user to twist 202 to break the connection between end cap 202 and skirt 204, such that end cap 202 can be removed from bottle 203 whilst skirt 204 is retained on bottle 203 by tuck-under 206.

[0008] It is important that skirt 204 is retained around the neck of the bottle on removal of end cap 202 to provide the tamper evidence security. If skirt 204 could be easily removed such as with removal of end cap 202, then it would be possible to remove the entire closure including end cap 202 and skirt 204 and tamper with the contents of the bottle before replacing the closure. However, one shortcoming of retaining skirt 204 around the neck of the bottle is that it becomes cumbersome to recycle the bottle after use. This is because skirt 204 must first be removed from the bottle so that the bottle can be recycled.

[0009] Removal of skirt 204 from bottle 203 can be achieved with a specialised removal tool. Typically, the removal tool is in the form of a blade or other sharp object which is inserted between the neck of bottle 203 and an internal facing surface of skirt 204. Skirt 204 can then be pried from bottle 203. However, this approach is time consuming, labour intensive, and can result in injury to a user. Other options include crushing the bottle with skirt attached, and then subjecting the crushed material to a separation process to separate glass and metal. However, this is costly since it involves machinery to carry out the crushing and separation processes.

[0010] In view of the above, it is desirable to provide a bottle closure which provides a simplified mechanism for removing a skirt from a bottle whilst retaining tamper evidence security.

[0011] It is an object of the invention to address at least one shortcoming of the prior art and/or provide a useful alternative. Summary of Invention

[0012] In a first aspect of the invention, there is provided a bottle closure comprising: a body with an open end and a closed end, and a fracture initiator configured to propagate a crack (e.g. a brittle crack) in the closure body from the open end toward the closed end on application of a critical applied stress.

[0013] In an embodiment, the fracture initiator is a score line on an internal facing surface of the body, the score line extending from the open end at least partially toward the closed end. By way of example, the score line may extend a quarter the length of the body, or a third the length of the body, or up to half the length of the body.

[0014] In an embodiment, the bottle closure further comprises a notch in the open end, wherein the notch is aligned with the fracture initiator.

[0015] In an embodiment, the bottle closure further comprises: an end cap portion defining the closed end; and a skirt portion defining the open end, wherein the skirt portion comprises the fracture initiator. Preferably, the skirt portion includes a support bead. Preferably, the fracture initiator is a score line on an internal facing surface of the skirt portion, the score line extending from the open end of the skirt portion and over the support bead. More preferably, the skirt portion further comprises a notch in the open end, wherein the notch is aligned with the score line. The notch may be of any geometric shape. However, it is preferred that the notch has an apex from which the score-line extends, e.g. the notch may be a semi-circular, triangular, diamond, or of another geometric shape having an apex.

[0016] In an embodiment, the skirt portion is attached to the end cap portion via a frangible connection. Preferably, the frangible connection is configured to break at a lower applied stress than the critical applied stress.

[0017] In embodiments in which the skirt portion is attached to the end cap portion via a frangible connection and in which the fracture initiator is a score line on an internal facing surface of the body, it is preferred that the score line extends from the open end to the frangible connection or to a location on the skirt portion adjacent the frangible connection.

[0018] In an embodiment the body has a substantially cylindrical cross-section. [0019] In an embodiment, the bottle closure is formed from a non-pliable / rigid material. Non- pliable and rigid materials are useful in the context of the invention since this permits a brittle fracture / crack to propagate on application of the critical applied stress. A preferred material is metal, of which a preferred metal is aluminium.

[0020] Soft materials, such as soft plastics (e.g. polyethylene terephthalate, low density polyethylene, high density polyethylene, polypropylene and the like) which are commonly used to form lids in soft drink or water bottles are generally not generally suitable in the context of the present invention. This is because these materials are soft and/or ductile, and therefore on application of stress these materials exhibit plastic deformation in the form of a tear rather than a brittle fracture which self-propagates as a crack.

[0021] In one or more embodiments, the bottle closure is not formed from a plastic material such as polyethylene terephthalate, low density polyethylene, high density polyethylene, or polypropylene.

[0022] In one or more embodiments, the bottle closure is not formed from a soft or ductile material.

[0023] In one or more embodiments, the crack is a brittle crack / fracture.

[0024] In one or more embodiment, the bottle closure is formed from a material that has a Young’s modulus that is 30 GPa or greater. Preferably, the Young’s modulus is 40 GPa or greater. More preferably, the Young’s modulus is 50 GPa or greater. Most preferably, the Young’s modulus is 60 GPa or greater.

[0025] In an embodiment, the bottle closure is threaded, and in particular, the end cap portion is threaded.

[0026] In an embodiment, the body has a substantially uniform thickness with a variance of up to +/- 0.07 mm.

[0027] In embodiments in which the fracture initiator is a score line, it is preferred that the score line has a depth that is from about 1/4 of a thickness of the body to about 1/2 the thickness of the body. [0028] In a second aspect of the invention there is provided a bottle comprising the bottle closure according to the first aspect of the invention and/or embodiments and/or forms thereof.

[0029] In a third aspect of the invention, there is provided a method comprising applying a bottle closure according to the first aspect of the invention and/or embodiments and/or forms thereof to a bottle.

[0030] In a fourth aspect of the invention, there is provided a method for forming a bottle closure from a blank, the method comprising: deep drawing the blank to form a bottle closure, the bottle closure comprising a body with an open end and a closed end, and forming a fracture initiator onto the body, the fracture initiator configured to propagate a crack in the body from the open end toward the closed end on application of a critical applied stress.

[0031] In an embodiment, the fracture initiator is formed on the body concomitantly with the step of deep drawing the blank.

[0032] In an embodiment, the method further comprises forming a notch in the open end of the skirt, the cut-out being aligned with the fracture initiator.

[0033] In an embodiment, the fracture initiator is in the form of a score line on an internal facing surface of the body, and the step of forming the fracture initiator includes scoring at least a portion of the internal facing surface of the cylindrical body with a projection on the pommel.

[0034] Preferably, the score line has a depth that is from about 1/4 of a thickness of the cylindrical body to about 1/2 the thickness of the cylindrical body, and/or the score line has a length that is at least about 1/4 up to about 1/2 a length of the cylindrical body.

[0035] In a fifth aspect of the invention, there is provided a pommel for use in a deep drawing method to form a bottle closure from a metal blank, the pommel comprising: a cylindrical body having a first end configured for contacting the metal blank to be deep drawn, a second end, and a longitudinal axis between the first end and the second end; a mounting portion configured to attach the pommel to a deep drawing apparatus at or adjacent to the second end; and a projection extending radially from the cylindrical body in a direction perpendicular to the longitudinal axis; wherein the projection is configured to introduce a score line onto an internal surface of the bottle closure during the deep drawing method.

[0036] In an embodiment, the cylindrical body includes an internal cavity for removably receiving and retaining an insert, the internal cavity having a first opening for insertion and withdrawal of the insert and a second opening through which a portion of the insert can project when the insert is within the internal cavity, the portion of the insert forming the projection.

[0037] In an embodiment, the projection is in the form of a blade that has a length parallel to the longitudinal axis, and wherein the length of the blade is at least half the length of the cylindrical body.

[0038] In a sixth aspect of the invention, there is provided a redraw ring for use in a deep drawing method to form a bottle closure from a metal blank, the redraw ring comprising: a cylindrical body having an outer peripheral wall portion and a central opening through which the metal blank can be extruded to form the bottle closure; wherein the outer peripheral wall comprises a leading edge which bounds the central opening and which is inwardly curved toward the central opening; and wherein the curvature of the leading edge is a blended radius of at least three successively increasing radii in a direction toward the central opening.

[0039] In an embodiment, a ratio of the three successively increasing radii is 1 : 1.12 to 1.22: 1.28 to 1.38. Preferably, the ratio is 1 : 1.15 to 1.19: 1.31 to 1.35.

[0040] In a seventh aspect of the invention there is provided apparatus for deep drawing a metal blank to form a bottle closure, the apparatus comprising a pommel according to the fifth aspect of the invention and/or embodiments and/or forms thereof, and a redraw ring according to the sixth aspect of the invention and/or embodiments and/or forms thereof.

[0041] In an embodiment the pommel and redraw ring are sized such that there is a clearance of 0.05 to about 0.07 between internal walls of the redraw ring and external walls of the pommel. [0042] Reference to any prior art in the specification is not an acknowledgment or suggestion that this prior art forms part of the common general knowledge in any jurisdiction or that this prior art could reasonably be expected to be understood, regarded as relevant, and/or combined with other pieces of prior art by a skilled person in the art.

[0043] As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additives, components, integers or steps.

[0044] Further aspects of the present invention and further embodiments of the aspects described in the preceding paragraphs will become apparent from the following description, given by way of example and with reference to the accompanying drawings.

Brief Description of Drawings

[0045] Figure 1 is an illustration of a wine bottle closure according to the prior art.

[0046] Figure 2 is an illustration of the wine bottle closure of Figure 1 after application to a wine bottle.

[0047] Figure 3A is an illustration of a wine bottle closure according to one aspect of the invention applied to a wine bottle with the end cap removed.

[0048] Figure 3B is an illustration showing the skirt portion of the wine bottle closure of Figure 3A splitting on application of a force thereto.

[0049] Figure 4A is a cross-sectional side view of a pommel according to one aspect of the invention which includes a scoring knife.

[0050] Figure 4B is a cross-sectional end view of the pommel of Figure 4A.

[0051] Figure 4C is a cross-sectional view of a redraw ring according to one aspect of the invention, and a bottle closure formed using this redraw ring with the pommel of Figure 4A. [0052] Figure 4D is a close-up cross-sectional view of the redraw ring of Figure 4C showing the detail of the curved leading edge.

[0053] Figure 5A is an illustration of a beer bottle closure applied to a beer bottle according to one aspect of the invention.

[0054] Figure 5B is an illustration showing the skirt portion of the beer bottle closure of Figure 5A splitting and flaring outward on application of a removal force thereto.

[0055] Figure 6 is an illustration of an embodiment of a wine bottle closure applied to a wine bottle, the wine bottle closure having a notch at the open end of the skirt.

Description of Embodiments

[0056] The invention generally relates to a bottle closure, and in particular wine and beer bottle closures having a cap portion and a skirt portion, wherein the skirt portion comprises a fracture initiator configured to propagate a fracture in the cylindrical body to split the bottle closure from a first end of the skirt portion distal from the end cap portion toward a second end of the skirt portion proximal to the end cap. In this way, the bottle closure can be easily removed from a bottle.

[0057] The skilled person will appreciate that a variety of means may be employed as the fracture initiator. For example, the fracture initiator may be in the form of a structural weakness or a stress concentrator on the bottle closure, a non-limiting disclosure of which includes: a notch or wedge cut or etched into the bottom lower end of the skirt portion, an etched channel, a series of holes or keyways, a tear-line, or a region weakened by modifying material properties e.g. through chemical or thermal treatment processes, etc.

[0058] Advantageously, the bottle closure of the invention provides a toolless means for removing the skirt portion from the bottle to permit a user to easily dispose of the bottle for recycling. Furthermore, no changes to the bottle itself are necessary to accommodate the bottle closure of the invention, e.g. the bottle closure can be applied to existing bottles.

[0059] The general operation of an embodiment of a wine bottle closure according to one aspect of the invention is described below. [0060] In use, the bottle closure is applied to a bottle to cover a bottle mouth. To open the bottle, a user twists the cap portion which causes the frangible portion to break and allows continued turning of the cap portion to unscrew the cap portion from the bottle. With the cap portion removed, the user is able to access the internal contents of the bottle via the mouth of the bottle. The cap portion can be screwed back onto the bottle if desired, e.g. if there is wine or other liquid left in the bottle.

[0061] When a user plans to dispose of the bottle, e.g. when the bottle is empty, the user is able to grip the skirt portion around the neck of the bottle and apply a downward force on the skirt portion (e.g. away from the mouth of the bottle) to slide the skirt portion along the neck and over at least a portion of the shoulder of the bottle (e.g. a flared neck portion). As the skirt portion rides over at least a portion of the shoulder of the bottle, the skirt portion is subjected to an outward force the fracture initiator causes a crack to propagate from the lower end of the skirt (e.g. the skirt portion adjacent the shoulder of the bottle / distal from the mouth of the bottle) toward the upper end of the skirt (e.g. the skirt portion proximal to the mouth of the bottle). Once the crack has propagated and split the skirt portion from the lower end of the skirt portion to the upper end, the skirt portion can then be easily removed by a user from the bottle. The skilled person will appreciate that the crack may not split the entire length of the skirt, e.g. an uppermost portion of the skirt may still be intact. However, a user can easily apply additional force to complete the split.

[0062] It is preferred that fracture initiator is configured to break at a higher applied stress than that required to break the frangible portion. This is to reduce the likelihood that the skirt will inadvertently split on opening the bottle.

[0063] Figures 3A and 3B provide an illustration of a user removing the skirt portion from a bottle. In particular, with reference to Figure 3A, a user’s hand grips the body of a wine bottle 302 whilst the other user’s other hand grips the skirt portion 306 of the wine bottle closure 308 around the neck 310 of the bottle. Downward arrow 312 illustrates the direction that the user moves hand 304 moves to effect removal of skirt portion 306. In this embodiment, skirt portion 306 includes a fracture initiator in the form of a score line on an internal surface of the skirt portion (illustrated as dashed line 314). Score line 314 is essentially a channel that is etched into internal surface of skirt portion 306. Although only a single score line is illustrated, the skilled person will appreciate that multiple score lines may be used. Score line 314 runs from the lower edge of skirt portion 306 at least partially toward the upper edge of skirt portion 306. The skilled person will appreciate that score line 314 may run from the lower edge of skirt portion 306 to the upper edge of skirt portion 306, or only part of the distance between the lower edge and the upper edge. In either case, as best shown in Figure 3B, skirt portion 306 is moved downward over shoulder 316 of wine bottle 302, the skirt portion is subjected to an outward force 316 which causes the skirt portion to fracture along the score line commencing at the lower edge of skirt portion 306. The fracture propagates along score line 314 toward the upper edge of skirt portion 306. Generally, the fracture will split skirt portion 306 which allows skirt portion to be unfurled and separated from wine bottle 302. However, if the fracture does not completely split skirt portion 306, a user can simply apply additional stress to complete the split.

[0064] The inventors have found that the score line should generally be in the form of a channel etched into the internal surface of the skirt with a consistent depth that is at a value in the range of from about 1/4 to about 1/2 the thickness of the skirt portion. Preferably the depth of the channel is about 1/3 the thickness of the skirt portion. If the channel depth is too shallow, then the increased resistance to fracture propagation may make it difficult for the fracture to propagate and split the skirt whereas if the channel depth is too deep then the skirt may be split unintentionally.

[0065] Likewise, the length of the score line should extend at least from the open end of the cap defined by the skirt toward the opposite end of the skirt at least over the support bead. This is desirable since the support bead would otherwise provide a barrier to fracture propagation.

[0066] In another aspect, the invention relates to a method of fabricating such a bottle closure.

[0067] The method generally includes deep drawing a blank with a pommel to form a bottle closure, the bottle closure comprising a body (generally a cylindrical body) with an open end and a closed end, and forming a fracture initiator onto the body, the fracture initiator configured to propagate a crack in the body from the open end toward the closed end on application of a critical applied stress. In a preferred embodiment, the fracture initiator is introduced during the step of deep drawing the blank to form the body. This is achieved, in part, by a specialized tool which will be described in more detail below.

[0068] The method advantageously provides a bottle closure of more uniform thickness as compared with prior art methods, which as discussed in the background section, result in formation of bottle closure with increasing thickness towards the bottom of the bottle closure. By way of example the thickness of a standard aluminium sheet used to form a wine bottle closure is 0.225 mm. The method of the present invention can be used to form a bottle closure with thickness of 0.225 mm +/- 0.07 mm. In contrast, standard methods of the prior art generally result in a bottle closure with greater variation in thickness.

[0069] One advantage of this greater uniformity of thickness is that less metal is required to produce the bottle closure. This enables the use of a smaller metal blank to produce the bottle closure which reduces the cost of production.

[0070] Further, the uniformity of thickness provided by the method of the present invention led to the realization that a fracture initiator, particularly in the form of a score line, could be introduced into the skirt during fabrication. As discussed above, prior art production methods generally result in a closure that has varying thickness. A consequence of this is that it is difficult to introduce and propagate a fracture to split the skirt since any fracture would need to traverse different wall thickness which may inhibit or prevent accurate fracture propagation.

[0071] By way of example, in the case where the fracture initiator is a score line on an internal surface of the skirt, the score line is generally formed as a channel of substantially constant depth from the internal surface of the skirt. However, since prior art skirts have varying thickness, the region of the skirt underlying the channel would also have varying thickness. If the channel depth is too shallow, an applied force may be insufficient to cause fracture in regions of high thickness. If the channel depth is increased to accommodate these thicker regions, then a user may inadvertently cause regions of lower thickness to crack on application of an unintentional force during normal usage of the bottle e.g. such as when opening the bottle.

[0072] As noted above, the fracture initiator may advantageously be formed into the bottle closure during manufacture of the bottle closure, and simultaneously with the process of deep drawing the blank to form the bottle closure. Accordingly, in a further aspect, the invention is directed to a pommel and/or a redraw ring for use in a deep drawing method described above.

[0073] The pommel comprises a pommel body and one or more projections, such as in the form of a scoring knife, to introduce a fracture initiator onto the bottle closure during the process of forming the bottle closure. The skilled person will appreciate that the type or nature of the projection depends on the type and nature of the fracture initiator that is desired. In the case of a wedge or notch, the pommel includes a corresponding projection for forming the wedge or notch. In the case of a score line, the projection may be in the form of a sharp edge or blade.

[0074] Figure 4A is a side sectional view of pommel 400 and Figure 4B is an end sectional view of pommel 400. Figure 4A illustrates a pommel 400 with generally cylindrical body that includes a tapered pommel end 402, a scoring knife 404 projecting radially outward along a partial length of pommel 400, a trimming ring 406, and a mount 408 for connecting the pommel 400 to a deep drawing apparatus (not shown). Figure 4B is a cross-sectional view of pommel 400. Pommel 400 includes an internal cavity 410 with square cross-section. Internal cavity 410 receives an insert 412 which in this case is in the form of an elongate rectangle with square cross-section. Insert 412 is retained within internal cavity 410 in such manner that a cutting edge (e.g. comer portion) of insert 412 projects radially outward of pommel 400 along a length thereof to form scoring knife 404. This arrangement advantageously allows insert 412 to be removed from within pommel 400 and replaced when the cutting edge becomes dulled after successive usage. The skilled person will appreciate that whilst the insert is generally depicted as having square cross-section, other shapes could be used.

[0075] The inventors have found that the cutting edge should project about 0.05mm to about 0.07mm from the outer surface of pommel 400. This provides adequate cut depth that the resultant score line on the internal surface the formed closure can be easily intentionally fractured by a user whilst avoiding inadvertent fracture which may arise during opening or closing of the closure.

[0076] Figure 4C is an illustration of redraw ring 414 and formed closure 416. The redraw ring includes an outer peripheral wall 418 having a support surface 419 which bounds a central opening 420. Outer peripheral wall 418 includes leading edge 422 which is inwardly curved toward central opening 420. In use, a metal blank (typically in the form of a sheet of a metal such as aluminium) is placed on support surface 419 and pommel 400 is engaged in a downward stroke until it contacts the metal blank. Pommel 400 continues to move downward through opening 420 which causes metal blank to be drawn and extruded over leading edge 422 and into 420 central opening in the clearance space between pommel 400 and the internal wall of redraw ring 414. At the completion of the downward stroke, pommel 400 is withdrawn and closure 416 is formed. Scoring knife 404 simultaneously scores the surface of the metal blank during the downward stroke such that closure 416 is formed with an internal facing score line. [0077] Through significant research and experimental testing, the inventors have found that providing an inwardly curved leading edge is important for forming a closure with more consistent wall thickness than prior art closures formed from a similar extrusion process. In particular, the inventors have found that providing a curved surface that comprises a blended radius of at least three successively increasing radii promotes greater uniformity of thickness during the extrusion process. This is more clearly illustrated in Figure 4D which is a close-up cross-sectional view of the leading edge of the redraw ring illustrated in Figure 4C. In the illustrated embodiment for forming a wine bottle closure, the leading edge has a curve defined by a blended radius comprising three radii of 0.9, 1.05, and 1.2 mm. Also illustrated is a fourth radius of 1.05 mm which in this case ensures that leading edge 422 curves inward so that it is flush with the internal wall of redraw ring 414.

[0078] Unexpectedly, the inventors have also found that the use of such a leading edge with this curved surface also provides an improved surface finish on the exterior surface of the closure and particularly when powder coated metal blank is used. As a result, further downstream surface treatment of the closure, such as ironing or polishing, are not required.

[0079] Whilst the invention has been described above in relation to wine bottle closures and related methods of manufacture, the skilled person will appreciate other bottle closures are contemplated. Accordingly, in another embodiment the bottle closure is a beer bottle closure. An exemplary beer bottle closure is illustrated in Figure 5A and Figure 5B.

[0080] Figure 5A and Figure 5B illustrate a beer bottle closure 500 on a beer bottle 502. The beer bottle closure is in the form of a threaded cap portion 504, support bead portion 506, and skirt portion 508 below bead portion 506. Skirt portion 508 includes a plurality of internal score lines 509 configured to propagate a crack in beer bottle closure 500 from the open end toward the closed end on application of a critical applied stress. Score lines 509 are not externally visible but are shown in broken lines in Figure 5 for illustrative purposes only.

[0081] Beer bottle closure 500 is threadably retained on beer bottle 502. To remove beer bottle closure 500 from beer bottle 502, the closure is rotated in the direction of arrow 510. This rotation causes beer bottle closure to ride upward on the internal threads of beer bottle 502 in the direction of arrow 512. As beer bottle closure 500 moves upward, skirt portion 508 rides up over the bead on beer bottle 502 which applies a critical stress to skirt portion 508 causing skirt portion 508 to fracture along the internal score lines into a number of segments 514, 516, 518 which deform and flare outwards but otherwise remain attached to beer bottle closure 500 as best illustrated in Figure 5B.

[0082] This arrangement advantageously provides tamper evidence security since skirt portion 508 is fractured and deformed to flare outwards whilst also removing all components of the closure from the bottle such that the bottle can be more easily recycled (e.g. there no skirt or tamper evidence ring is retained on the bottle after removal of the closure).

[0083] Figure 6 illustrates a further embodiment of a wine bottle closure 600 on a wine bottle 602. The wine bottle closure 600 is similar to that depicted in Figures 2, 3 A, and 3B. However, in this embodiment, the closure 600 additionally comprises a semi-circular cut-out or notch 604 in the open end of skirt 606. The skilled person will appreciate that notches of other shapes could be used, e.g. triangular etc. Semi-circular notch 604 is aligned with the score line 608 such that score line 608 terminates at an apex of notch 604. The inventors have found that this provides a number of advantages. By way of example, the presence of notch 604 provides a visual identifier to a user of the location of score line 608 which aids the user to correctly position their hands to remove skirt 606. Further, notch 604 acts to concentrate stress generated during removal on score line 608 to more easily and effectively propagate a fracture and split skirt 606 for removal.

[0084] It is preferred that the bottom outer edges of notch 604 are smoothed, e.g. have a radial geometry. If the outer edges of notch 604 were sharp edges, then these would pose an injury hazard to a user. That is, a user may cut themselves on the sharp edges. In one form, the outer edges have a radius that is greater than a radius of notch 604.

[0085] It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

Claims

1. A bottle closure comprising: a body with an open end and a closed end, and a fracture initiator configured to propagate a crack in the closure body from the open end toward the closed end on application of a critical applied stress.

2. The bottle closure of claim 1, further comprising: an end cap portion defining the closed end; a skirt portion defining the open end, wherein the skirt portion comprises the fracture initiator.

3. The bottle closure of any one of the preceding claims, wherein the skirt portion includes a support bead.

4. The bottle closure of claim 3, wherein the fracture initiator is a score line on an internal facing surface of the skirt portion, the score line extending from the open end of the skirt portion and over the support bead.

5. The bottle closure of any one of the preceding claims, wherein the skirt portion is attached to the end cap portion via a frangible connection.

6. The bottle closure of claim 5, wherein the frangible connection is configured to break at a lower applied stress than the critical applied stress.

7. The bottle closure of claim 5 or 6, wherein the fracture initiator is a score line on an internal facing surface of the body, the score line extending from the open end to the frangible connection or to a location on the skirt portion adjacent the frangible connection.

8. The bottle closure of any one of the preceding claims, wherein the body has a substantially uniform thickness with a variance of up to +/- 0.07 mm.

9. The bottle closure of claims 4 or 7, wherein the score line has a depth that is from about 1/4 of a thickness of the body to about 1/2 the thickness of the body.

10. A bottle comprising the bottle closure of any one of the preceding claims.

11. A method comprising applying a bottle closure according to any one of claims 1 to 9 to a bottle.

12. A method for forming a bottle closure from a blank, the method comprising: deep drawing the blank to form a bottle closure, the bottle closure comprising a body with an open end and a closed end, and forming a fracture initiator onto the body, the fracture initiator configured to propagate a crack in the body from the open end toward the closed end on application of a critical applied stress.

13. The method of claim 12, wherein the fracture initiator is formed on the body concomitantly with the step of deep drawing the blank.

14. The method of claim 12 or 13, wherein the fracture initiator is in the form of a score line on an internal facing surface of the body, and the step of forming the fracture initiator includes scoring at least a portion of the internal facing surface of the cylindrical body with a projection on the pommel.

15. The method of claim 14, wherein the score line has a depth that is from about 1/4 of a thickness of the skirt to about 1/2 the thickness of the skirt, and/or the score line has a length that is at least about 1/4 up to about 1/2 a length of the cylindrical body.

16. A pommel for use in a deep drawing method to form a bottle closure from a metal blank, the pommel comprising: a cylindrical body having a first end configured for contacting the metal blank to be deep drawn, a second end, and a longitudinal axis between the first end and the second end; a mounting portion configured to attach the pommel to a deep drawing apparatus at or adjacent to the second end; and a projection extending radially from the cylindrical body in a direction perpendicular to the longitudinal axis; wherein the projection is configured to introduce a score line onto an internal surface of the bottle closure during the deep drawing method.

17. The pommel of claim 16, wherein the cylindrical body includes an internal cavity for removably receiving and retaining an insert, the internal cavity having a first opening for insertion and withdrawal of the insert and a second opening through which a portion of the insert can project when the insert is within the internal cavity, the portion of the insert forming the projection.

18. The pommel of claim 16 or 17, wherein the projection is in the form of a blade that has a length parallel to the longitudinal axis, and wherein the length of the blade is at least half the length of the cylindrical body.

19. A redraw ring for use in a deep drawing method to form a bottle closure from a metal blank, the redraw ring comprising: a cylindrical body having an outer peripheral wall portion and a central opening through which the metal blank can be extruded to form the bottle closure; wherein the outer peripheral wall comprises a leading edge which bounds the central opening, and which is inwardly curved toward the central opening; and wherein the curvature of the leading edge is a blended radius of at least three successively increasing radii in a direction toward the central opening.

20. The redraw ring of claim 19, wherein a ratio of the three successively increasing radii is 1 : 1.12 to 1.22: 1.28 to 1.38.