Container closures

Abstract

 This invention relates to container closures and to methods of sealing the container neck on filling of the containers.
A closure assembly comprises a plug 4 adapted to be inserted into the neck 1 of a container to effect an aseptic seal with the container neck 1 and a cap 11 comprising a skirt 13 provided with formations 12 that are adapted to co-operate with complementary formations 2 provided on the container neck 1. The cap 11 and the neck formations 2 are so arranged that the cap 11 can be turned from a fully applied condition to a release position for removal of the cap 11 from the neck 1, the plug 4 being adapted to be inserted into the neck 1 to effect an aseptic seal of the neck 1 prior to application of the cap 11. On subsequent removal of the fully applied cap 11 from the neck 1, the plug 4 is withdrawn from the neck 1 by being held captive to the cap 11.

Description

[0001] This invention relates to container closures and to methods of sealing the container neck on filling of the containers.

[0002] For many products such as tablets or liquid medicines supplied in bottles, or other necked-containers, there is a requirement to guarantee an aseptic fill condition at the container filling station. This requires the container neck to be sealably closed in some way after filling.

[0003] For many products it is desirable that the closure comprises a cap that can be gripped and turned to open the container for access to the contents. Such caps are generally provided with some form of sealing disc which is effective in use to prevent moisture reaching the contents. If the sealing disc is to be relied upon initially to provide an aseptic seal then the capping machinery needs to be arranged in an aseptic zone, making it difficult to adjust and maintain without breaching the sterile zone.

[0004] In order to overcome that problem it has been the practice in some cases to apply, in the aseptic zone, a foil closure across the free end of the container neck, the foil being adhered in some manner to the container neck. A problem with that arrangement is that when the container is first opened by releasing the closure cap, the user has to remove or break the foil to gain access to the contents. Depending upon how the foil is removed the contents risk being contaminated by the use of a tool for removal/breaking of the foil.

[0005] According to one aspect of the invention we provide a closure assembly adapted to co-operate with the neck of a container, the closure assembly comprising a cap and a plug, the plug being adapted to be inserted into the neck of a container to effect an aseptic seal with the container neck, the cap comprising a skirt provided on the internal surface thereof with formations that are adapted to co-operate with complementary formations provided on the external wall of the container neck, the cap and the neck formations being so arranged that the cap can be turned from a fully applied condition to a release position for removal of the cap from the neck, the plug being adapted to be inserted into the neck to effect an aseptic seal of the neck prior to application of the cap, the cap and the plug being secured together in the assembled condition of the cap and plug on the container neck, the arrangement being such that on subsequent removal of the fully applied cap from the neck, the plug is withdrawn from the neck by being held captive to the cap.

[0006] Since removal of the cap results in removal of the plug, the invention can assist the user in gaining access to the product.

[0007] The cap and plug may be adapted to be mechanically secured together in the assembled condition of the cap and plug on the container neck.

[0008] The formations on the cap and neck may be screw threads, bayonet connections, or any of the other formations which permit removal of a cap on turning of the cap relative to the container neck. Some such arrangements may involve the application of a diametral squeezing force to part of the cap skirt to enable turning of the cap.

[0009] The cap can be applied by either pushing over the neck formations, or in appropriate cases by screwing down. Similarly, the plug could be twisted on insertion if this proved beneficial.

[0010] Although there may be arranged to be an adhesive connection between the cap and the plug, or bonding performed in some other way, preferably the cap and the plug are adapted to be snap-engageable together.

[0011] Such a snap engagement is preferably afforded by providing the plug with a peripheral radially-directed flange that is engageable in an internal recess defined in the cap, preferably adjacent to the connection between the sidewall and the top wall of the cap.

[0012] The plug and the cap can be mechanically joined in several ways - purely mechanically with a snap fitting or, for example, by using a foil layer as a medium for induction heating of materials that will not bond to the bottle.

[0013] The plug is preferably substantially of inverted top-hat shape. Such a plug will, with advantage, reduce the headspace in the container. This will reduce the damaging effect of headspace oxygen on sensitive products, at the same time as causing air to leave the container during sealing of the plug, rather than risking the ingress of potentially contaminated surrounding air.

[0014] The outer profile of the plug need not necessarily be frusto-conical - one arrangement might have a plug whose 'active' section was more barrel shaped (ie convex), so that sealing takes place some way into the container neck - combined with a container neck whose inner diameter is constricted at a position spaced from the free end of the neck. This could eliminate the requirement to clean the outside of the neck.

[0015] The cap and plug may be made of different materials which allows them to be optimised for their respective functions. For example, the plug may include oxygen absorbing resins, be of a high barrier blend of materials, or formed as a multilayer or coated structure to provide a high barrier function, or may be of a 'low taint' formulation. The cap material may be chosen to provide tight sealing on threads, senior-friendly opening forces, etc, without compromising seal integrity. The material from which the plug is formed may be permeable to particular gases.

[0016] An additional layer can be added across the top of the plug to improve the gas barrier characteristics of the assembly. This could be applied to the plug before or after it is fitted to the bottle, and because of its location does not have to be cleaned. The additional layer may comprise a foil or a membrane. Alternatively the additional layer may comprise a cap insert, to ease handling. The plug may be configured with a suitably dimensioned land to facilitate application/sealing of the additional layer.

[0017] The plug preferably comprises a storage region which provides a storage space.

[0018] The storage region is preferably provided by a recess which when the plug is in a fully applied condition extends into the volume defined by the container.

[0019] Where the plug is provided with an additional layer, the additional layer acts to close the storage region.

[0020] The storage region of the plug can be used to contain materials that modify the atmosphere or the product. Such materials do not need to be sterilised since they will not come into contact with the product, nor will they get wet. They will however be enclosed in the storage region by an additional layer, if fitted. For example, putting a small amount of an oxygen scavenger in the storage region, under foil, would improve juice/alcohol quality or shelf-life of a product.

[0021] If the additional layer is impermeable so as to act as a gas barrier then advantageously only oxygen from the product will be taken by the scavenger and not from atmosphere so that the scavenger does not become prematurely saturated. Another possibility is that the storage region may hold materials which emit odours which leach through the plug and into the product by osmosis so as to ensure good flavour characteristics over the shelf life of the product.

[0022] Also, the storage region of the plug, under the cap, could be used to include prize tokens, leaflets, promotional gadgets, light activated singing 'chips' (as found in Birthday cards etc).

[0023] Preferably the cap and container neck are provided with tamper-evident features. Such features are well-known in the art and need not be further described.

[0024] According to a second aspect of the invention we provide a method of filling a container utilising a closure assembly in accordance with the first aspect of the invention, the method comprising inserting the contents through the open neck of the container, and in an aseptic zone bringing the plug to the neck of the container and urging the plug either partially or completely into the neck, so as to achieve in either case an aseptic seal of the plug to the bottle neck, and then bringing the container to a capping station at which the cap is applied.

[0025] In the circumstance that the plug is not fully applied to the bottle neck in the aseptic zone, but nevertheless creates a sterile seal, the subsequent application of the cap is preferably arranged to urge the plug to the fully applied condition.

[0026] The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:

Figures 1 to 4 are vertical cross-sections showing successive stages in the sealing and capping of a bottle;

Figure 5 shows the subsequent unscrewing of the closure; and

Figure 6 shows a vertical cross-section of a second embodiment of the invention.

[0027] With reference to Figure 1, this shows a vertical cross-section of a bottle neck 1 of substantially cylindrical form provided towards the upper end thereof with external screw threads 2 and beneath those with an annular retaining rib 3.

[0028] A plug 4 of inverted top-hat shape has a rounded corner 5 between the plug side wall and base 6 in order to minimise the risk of dirt, germs or bacteria being trapped in crevices. The plug has a flat annular rim 7 which is of greater radial width than that of the free end 8 of the neck so as to project radially outwards of the neck free end 8 when the plug has been fully inserted into the neck, that is when the lower surface of the rim 7 abuts the neck free end 8, as in Figure 2.

[0029] A foil portion 18 is affixed to the upper surface of the rim 7. The foil portion 18 closes recess 21 which is defined by internal surfaces of the plug 4. As hereinbefore discussed the recess 21 provides a storage region for various objects and/or substances.

[0030] Insertion of the plug 4 into the neck 1 can be carried out in an aseptic zone of a bottle filling machine, as soon as the contents have been fed into the bottle. Suitable mechanisms can be provided in the aseptic zone for bringing a plug into register with the neck, and then urging the plug downwards relative to the neck, by a sufficient amount to effect an aseptic seal between the plug 4 and the neck 1.

[0031] In the illustrated embodiment the side walls 9 of the plug 4 are provided with a taper to effect a seal on insertion of the plug into the neck. The seal is effected between the tapered side wall 9 of the plug and the plain cylindrical internal surface 10 of the neck.

[0032] In Figure 2 the plug 4 is shown fully inserted into the neck 1, the full insertion of the plug having been carried out in the aseptic zone. In a modified method, not illustrated, the plug is only partially inserted into the neck in the aseptic zone, but by a sufficient amount to achieve an aseptic seal between the plug wall 9 and the neck surface 10.

[0033] Figures 2, 3 and 4 show a cap 11 being applied to the bottle, preferably by urging the cap downwards onto the bottle with a sufficient force to cause the internal screw threads 12 on the cap skirt 13 to snap over the threads 2 on the neck.

[0034] The lower margin of the cap skirt comprises an integral tamper evident retaining ring 14, of well-known form, which snaps over the retaining rib 3 on the neck as the cap reaches the fully applied condition shown in Figure 4.

[0035] Ring 14 is connected to the remainder of the cap by a frangible connection 16 of known arrangement.

[0036] The cap is provided internally with an annular rib 15, of rounded cross-sectional profile, spaced from the cap end wall so as to define an annular corner recess 17 in the corner defined by the connection between the cap base and skirt.

[0037] The radial dimensions of rib 15 and that of the radially outer margin of the plug rim 7 are chosen such that as the cap closely approaches the fully applied condition of Figure 4, the rim 7 snaps past the rib 15 into the recess 17. Moreover, those radial dimensions are such that on subsequent unscrewing of the cap by the customer, sufficient force is exerted by cap rib 15 on the plug flange 7 to remove the plug from the neck. Thus, the closure combination of plug and cap is removable as an entity from the bottle, simply by unscrewing of the cap.

[0038] With reference now to Figure 6, there is shown a second embodiment of the invention is which a plug 4' and a foil closure 18' are adapted to be held captive to a cap 11'. The plug 4' and cap 11' are similar to those shown in Figures 1 to 5, however the radial width of annular rim 7' is smaller than that of plug 4 and the cap 11' is not provided with a rib 15. A heat sensitive adhesive is applied to both sides of the foil 18'. The foil 18' is then applied onto the upper surface of the rim 7'. The plug 4' is then inserted into the neck 1' in an aseptic zone and the cap 11' is urged onto said neck. In so doing adhesive on the upper surface of the foil 18' contacts with underside 21' of roof 20' of the cap 11'. A heat induction process can be used to bond the foil with the cap.

Claims

1. A closure assembly adapted to co-operate with the neck (1) of a container, the closure assembly comprising a cap (11) and a plug (4), the plug (4) being adapted to be inserted into the neck (1) of a container to effect an aseptic seal with the container neck (1), the cap (11) comprising a skirt (13) provided on the internal surface thereof with formations (12) that are adapted to co-operate with complementary formations (2) provided on the external wall of the container neck (1), the cap (11) and the neck formations (2) being so arranged that the cap (11) can be turned from a fully applied condition to a release position for removal of the cap (11) from the neck (1), the plug (4) being adapted to be inserted into the neck (1) to effect an aseptic seal of the neck (1) prior to application of the cap (11), the cap (11) and the plug (4) being secured together in an assembled condition of the cap (11) and plug (4) on the container neck (11), the arrangement being such that on subsequent removal of the fully applied cap (11) from the neck (1), the plug (4) is withdrawn from the neck(1) by being held captive to the cap(11).

2. The closure assembly of claim 1 wherein the cap (11) and plug (4) are adapted to be mechanically secured together in the assembled condition of the cap (11) and plug (4) on the container neck (1).

3. The closure assembly of claim 1 or claim 2 wherein the formations (12,2) on the cap (11) and neck (1) are screw threads.

4. The closure assembly of claim 1 or claim 2 wherein the formations on the cap (11) and neck (1) are bayonet connections.

5. The closure assembly of any one of the preceding claims wherein, in use, the application of a diametral squeezing force to part of the cap skirt (13) enables turning of the cap (11).

6. The closure assembly of any one of the preceding claims having an adhesive connection between the cap (11) and the plug (4).

7. The closure assembly of any one of the preceding claims wherein the cap (11) and the plug (4) are adapted to be snap-engageable together.

8. The closure assembly of claim 7 wherein the snap engagement is afforded by providing the plug (4) with a peripheral radially-directed flange (7) that is engageable in an internal recess (17) defined in the cap (11).

9. The closure assembly of claim 8 wherein the internal recess (17) is adjacent the connection between the sidewall and the top wall of the cap (11).

10. The closure assembly of any one of the preceding claims wherein the plug (4) and the cap (11) are joined using a foil layer as a medium for induction heating of materials that will not bond to the bottle.

11. The closure assembly of any one of the preceding claims wherein the plug (4) is substantially of inverted top-hat shape to reduce the headspace in the container. .

12. The closure assembly of any one of the preceding claims wherein part of the outer profile of the plug (4) is barrel shaped, so that sealing takes place a distance into the container neck (1), the inner diameter of the container neck (1) being constricted at a position spaced from the free end of the neck (1).

13. The closure assembly of any one of the preceding claims wherein the plug (4) is manufactured from a material comprising oxygen absorbing resins.

14. The closure assembly of any one of the preceding claims wherein the plug (4) comprises a storage region (21) which provides a storage space.

15. The closure assembly of claim 14 wherein the storage region (21) is provided by a recess which extends into the volume defined by the container when the plug (4) is in the fully applied condition.

16. The closure assembly of claim 14 or claim 15 wherein the storage region (21) of the plug (4) is used to contain materials that modify the atmosphere or the product.

17. The closure assembly of any one of the preceding claims having an additional layer across the top of the plug (4) to improve the gas barrier characteristics of the assembly.

18. The closure assembly of claim 17 wherein the additional layer comprises a foil (18) or a membrane.

19. The closure assembly of claim 17 wherein the additional layer comprises a cap insert.

20. The closure assembly of any one of claims 17 to 19 wherein the plug (4) has a land to facilitate application and sealing of the additional layer.

21. The closure assembly of any one of claims 17 to 20 as dependent on any one of claims 14 to 16 wherein the additional layer acts to close the storage region (4).

22. The closure assembly of any one of the preceding claims wherein the cap (11) and container neck (1) are provided with tamper-evident features (14,16).

23. A method of filling a container utilising a closure assembly in accordance with any one of claims 1 to 22, the method comprising inserting the contents through the open neck (1) of the container, and in an aseptic zone bringing the plug (4) to the neck (1) of the container and urging the plug (4) either partially or completely into the neck (1), so as to achieve in either case an aseptic seal of the plug (4) to the bottle neck (1), and then bringing the container to a capping station at which the cap (11) is applied.

24. The method of claim 23 wherein, in the circumstance that the plug (4) is not fully applied to the bottle neck (1) in the aseptic zone, but nevertheless creates a sterile seal, the subsequent application of the cap (11) is arranged to urge the plug (4) to the fully applied condition.

Drawing