MXPA06010858A

MXPA06010858A - Closure with integral gas barrier.

Info

Publication number: MXPA06010858A
Application number: MXPA06010858A
Authority: MX
Inventors: Spreckelsen Henning Von; Peter Michael Mcgeough
Original assignee: Bapco Closures Res Ltd
Priority date: 2004-03-24
Filing date: 2005-03-24
Publication date: 2007-07-25
Also published as: ZA200607585B; EP1730045A1; GB2412368B; WO2005092728A1; GB0406630D0; AU2005225604B2; GB0506128D0; AU2005225604A1; GB2412366B; GB2412366A; NZ550125A; CN1934006B; CN1934006A; GB2412368A; US20080035600A1

Abstract

A cap (2) suitable for use with a PET beverage bottle has an integral gas barrier provided by a plastics-coated aluminium foil disc (30) having its peripheral edge (32) embedded into the plastics internal or external surface (40) of a top panel (4) of the cap or of a valve (20). A plastics component (28) from which the cap (2) can be produced is described. The component (28) has a recess (48) defined by a sacrificial wall (50) formed inwardly of a resealing valve (20).

Description

CLOSURE WITH INTEGRAL GAS BARRIER.

TECHNICAL FIELD: The present invention relates to the closure with an integral gas barrier. More specifically, the invention relates to the field of closures for packages for liquids that require a gas or moisture barrier. The invention is relevant in particular in the field of glass, plastics, including thermoformed plastics or metal bottles or jars and cartons without pressure.

Certain liquids, such as beer, are particularly susceptible to oxygen levels. The control of oxygen levels is also essential, in the aseptic and extended life (ESL) package to prevent waste, corrupting and discoloration during the entry of oxygen.

The invention is there concerning the control of gases within a container and, more specifically, the impact of the closure in this edition. A gas barrier is required to prevent both the escape of carbon dioxide from carbonated beverages, packed under pressure and the ingress of oxygen by the closure. The air can also be introduced into the container during a coating process.

ART BACKGROUND. The crown cork caps are pressed into a glass bottle neck, providing an effective package solution with excellent gas barrier characteristics.

The aluminum screw caps are also used with glass bottles. These have a material applied liner post fitted to provide a seal. Another lock that relies on the gas barrier the metal provides is a pull closure of the ring consisting of a molded metal cap over the mouth and neck and providing at least one edge with a ring pull to allow removal. This closure is not retractable WO 03/022705 (Termo limited caps-Mestriner) teaches the use of a metal plane sealing the disk that is retained is a bed on the edge of the bottle by a plastic ring that can be removed by means of of a plug. Once again, the thermosheath closure is not retractable.

The metal screw closures are less convenient for use with plastic bottles as their use requires a high axial load that would damage the neck of the plastic bottle.

Another option is to use a molded closure with a loss of multi-layered sheet plotter, which is inserted into the body of the closure. This assembly was applied after filling. The mounted closure is exposed to a field of induction energy this closing the neck sheet of the bottle. This seal sheet provides a gas barrier. However, such loss of the leaf seals is typically very difficult to remove and the closure system provides poor seal operation once the leaf element is removed. This solution is also not suitable for aseptic applications like microbes and got pollution trapped behind the loose leaf liner. The cap sterilization systems used are unable to suppress such contamination.

Progress in gas bottle barriers, including sweeping agents attached to PET polymers, means that it is now practical to use in plastic bottles for products such as beer and other oxygen sensitive concoctions. However there is a need for a convenient closure for use in plastic bottles that offer a high integrity gas barrier and is preferably retractable.

PREVIOUS DELARTE SOLUTIONS.

A typical screw closure for use with a bottle is described in US4658976 (Aluminum Company of America - Pohlenz). The seal lid is provided by means of a plastics liner at the top of the cap to seal again an edge of the mouth of the bottle. This type of cap is commonly used for mineral water and carbonated soft drinks.

The presence of a valve that sits inside the neck of the bottle is a preferred solution for the ability to reseal in a collapsible plastic closure. A good seal is essential for plastic containers that have been processed in a line of Pasteurization like this can result in heat deformations in the neck of the bottle. A long valve is preferable to eliminate the risk of the output arising from this deformation.

Although the Aluminum Company of America does not specifically address the problem of the gas barrier; others have used the same plastic line plotter or taco approach to address this problem. EVOH (ethylene vinyl alcohol) or rubber materials have been tried, but although this provides a gas barrier, they do not form good moisture barriers.

Owens-Illinois Closure Ine, has, for example, announced a molding on the liner seal that uses multiple thin layers of barrier material as described in US6399170 (Rhine Wine). This material tends to be expansive and fragile and is not convenient to function as a seal. Accordingly several designs have been suggested for the use of such barrier with other sealing structures. See EP-A-1081 058 (Riffer) and US 2003/0057175 Al (Willingham et al.). These molded liner sealers have been developed to provide equal levels of gas barrier or better than in the sheet. While aluminum foil has excellent gas and moisture barrier properties, it is undesirable to allow the exposed metal to enter into contact with many products due to its propensity to cause corrosion under prolonged contact conditions.

The problems of providing an oxygen barrier with plastic or metal / plastic or metal closure are also discussed in WO 02/14171 (White Cap, Inc). A oil-free, single layer plastics liner is proposed as a liner to provide a gas barrier and also to act as a sealer together. For example, a solution results in a closure that requires a high torque torsion to remove if a good seal is reached. Closures made of composite materials are also relatively expensive to produce. Again sealing an edge of the mouth of the bottle also requires the edge to be a level and smooth. These conditions do not allow a possible heat treatment afterwards.

In order to minimize the amount of oxygen entrained in the bottleneck during the capsule process, it is normal for nitrogen to be continuously blown about the necks of the bottles. The inert nitrogen displaces any oxygen trapped in the neck of the bottle on the contents. However, nitrogen does not displace the oxygen that is trapped in the caps as it is diminished in the neck. As a result of a small but significant amount of oxygen creeps in and inevitably traps inside the sealed bottles. This is a particular problem for screw cap closures.

TECHNICAL PROBLEM: To provide a complete solution for the gas-proof package in plastic containers that could have twisted necks, if necessary to solve the technical problem of supplying a retractable, resealable closure with an integral gas barrier that can be adjusted with loading minimum of the bottle cap during coating while being aseptic compatible.

A future technical problem is presented by the need to prevent oxygen being introduced into the container when the lock is adjusted.

SOLUTION OF THE INVENTION: Instead of plastic tracers and wads, the present invention provides a solution in which the advantages of a gas barrier in an aluminum sheet are provided within plastic bushes. If it is there, it is possible to produce closures made of two materials, a lightweight, flexible plastic coated aluminum ferrule component, in a variety of configurations that solve the identified technical problem.

The present invention provides a collapsible plastic bushing having an upper panel, skirt and plastic coated element of the aluminum foil fused to the bushing to provide a gas barrier by inhibiting the flow of gas through the bushing, such that the The aluminum peripheral edge of the blade element can not come into contact with the contents of a container closed by the bushing in use. This can be linked by fixing the gas barrier on the top panel or interposed on a valve plate. New design possibilities are opened by an appreciation that the gas barrier does not need the face of the contents of the container to be effective.

Alternatively, the present invention also provides a collapsible plastic cap having an upper panel and skirt, wherein the aluminum-plated plastic lined liner has a peripheral edge that is engaged and fused to the surface of the cap.

By using the plastic coated liner with a fitted edge the risk of contamination of an exposed aluminum edge is avoided. The key to edge fusion in the cap lies in a realization that with a suitable arrangement of sacrificed walls or the resemblance in the component from which the cap is made induction heating can be employed to fit the edge completely without leaving any cracks that would prevent effective sterilization of the cap assembly.

This type of cap can be used together with a valve to provide reseatability. It can also be used with a snap on the treated caps. The edge is preferably fitted on the inner surface of the upper panel or a valve of the cap, but it can also be fitted on the external surface of the upper panel or wrapped on the cap of the cap and fitted on the edge. By melting the edge in the cap material the same level of protection is provided with the normal layer on the larger surface of the sheet.

The invention also provides a plastic component for use in the manufacture of said bushing, wherein an annular wall extends in order to define a slit for receiving the sheet plotter. The slit can be under or the top panel lid. Preferably the annular wall has an intermediate, cross-sectional portion reduced in order to allow a lower part of the wall to be bent back towards the upper panel to preserve the peripheral edge of the sheet liner during production.

The present invention will provide in the future a method of production of bushing for plastic components comprising an upper panel surrounded by a bank, receiving a slit for a barrier of the sheet, and a sacrificial wall, the method covers the steps of placing a barrier of the sheet in the slit and heating the wall to melt the plastic material of the wall in order to fit one edge of the sheet into the cap.

The heating is preferably carried out by the induction heating of the sheet to melt the wall, as this prevents contact with the bushing and promotes a clean and fast production.

For example a method is aseptic friendly as the resulting bushing has smooth surfaces and no additional cracks in which the bacteria can escape when the bushing is rinsing and being flushed.

Other characteristics of the invention are defined in the appendix of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS: In order that the invention can be well understood, four coverages of that will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 shows the half of the longitudinal section by a first cover of a bushing shown incompletely assembled; Figure 2 shows a detail of the assembly of the bushing of Figure 1 during the first production step; Figure 3 shows the same detail as in Figure 2 in a finished bushing after the second step of production; Figure 4 shows a longitudinal section through a second covering of a cap assembly; Figure 5 Shows the same section as in Figure 4 during the first production step; Figure 6 Shows the same section as in Figure 4 and 5 in a finished bushing after the second step of production; Figure 7 shows a longitudinal section, exploded by a third cover of the cap assembly; Figure 8 Shows the same section as in Figure 7 after the bushing has been fully assembled; Figure 9 shows a longitudinal section through a fourth cover of an exploded bushing assembly; Figure 10 shows the same section as in Figure 9 after the bushing has been fitted to the neck of a container or bottle; Figure 11 shows a variation of a part of the component shown in Figure 9; Figure 12 shows a longitudinal section, exploded by a fifth cover of a bushing.

Figure 13 shows the same section as in Figure 12 after the bushing has been fully assembled; Figure 14 shows a longitudinal section through a sixth cover of the bushing; Y Figure 15 shows a longitudinal section through a seventh coverage of the bushing.

DETAILED DESCRIPTION OF PREFERRED COVERAGES A plastic cap 2 has an upper panel 4 and a border 6. The cap 2 is intended for use with a PET container with PCO1 or BPF2 (or any other standard) neck finished with the typical neck diameter as 28, 33, 38 , 43 or 45 mm. It can be appreciated that the principle of the invention can be applied to other closures and diameters. However, the coverages that were described are examples only.

Seven coverages are described and in each similar part are identified by similar numbers of the reference.

Referring first to the coverage of Figures 1 to 3, an inner wall 8 of the edge 6 has thread formations 10. A smaller edge of the edge is connected by means of a breakable area 12 to a collar of the tamper bandage 14 which engages with and is retained in an external formation of the neck of the bottle in order to provide evidence of the tamper.

An annular seal of the valve 20 is dependent on the upper inner panel 4 of the edge 6. The valve is positioned for its outer surface 22 to reseal an internal surface of the neck of the bottle when the cap 2 is installed.

The plastic cap 2 as described so far is conventional and commercially available.

The cap 2 of the invention is a mounting of the above-described plastic components 28 with a barrier sheet liner 30 of aluminum sheet. 1 Plastic Closures Only - definition of a standard finished neck used in the United States. 2 British Plastics Federation - Definition of a standard finished collar used in the United Kingdom.

The sheet of the liner 30 is placed inside the valve 20. The liner 30 is a disc of the sheet having a peripheral edge 32. The disc 30 is cut from a piece of aluminum foil coated with plastic and so so much is the peripheral edge 32 has exposed aluminum between 2 thin layers of the plastics or membranes. Liner 30 is made of a double-side inducing heat sealing (IHS) sheet as described, for example, in GB237740A (Spreckelsen McGeough Ltd.) The term of the liner sheet may normally be understood in the art of referring to the loss of element. It will be appreciated that in the context of host 30 of the liner it will be soldered on it. Cap 2 as described in the following detail.

In order to allow the edge 32 to be fitted and fused to an inner surface 40 of the upper panel 4, the bushing s produced for a molded impact the plastic component which initially has a receiving recess 48b for the blade disc 30 formed by a sacrificial wall annular 50 depending on the inner surface 40 just near the valve 20. The wall 50 has an upper part 52 and a smaller part 54 separated by a reduced intermediate cross-section portion 56 running around the entire circumference of the annular wall 50 The smaller part 54 ends on the outside projecting a widened foot 58. The smaller part 54 is designed to be able to be folded backing close to the hinge providing inside the top 52 with the foot 58 terminating parallel to the inner surface 40. of the upper panel 4 as shown in Figure 2. In this configuration of the foot 58 retains the sheet of the folio 30 in position.

During production, the plastic components 28 are inverted in a disc sheet 30 is drilled and located in each plastic component 28 within the wall 50. A tool is then brought down from the panel 4. The face of the tool is formed from engaging with the lower part 54 of the wall 50 and sent down on the edge 32 of the disk and then the future pressure drops and heats (by means of induction) the mounting that the plastic material of the wall 50 smoothes and circulates on the edge 32 for fit it on the inner surface 40 in the top panel 4 as shown in Figure 3 by fusing the plastics of the liner with the plastic of the component 28. These results in the sheet liner 30 being welded on both sides of the plastic cap 2. The retention of the disc passage and the insertion step can be the cut carried as separate operations. The use of the double sided IHS sheet allows the wall 50 to be indirectly melted by contact with the heated sheet.

The blade of disc 30 can be served slightly to facilitate the giving and exact location of the aid.

The disk of the sheet 30 can be sterilized first of the insert in the recess 48.

The disc of the blade 30 may have a small diameter than those of the neck of the bottle or container by which the seals are fitted. The liner sheet will also completely cover the surface of the top panel 4 specifically if it is externally mounted.

When the disc 30 is dropped in 1 recess 48 they may be of a large size and have the peripheral edge pressed down the inner surface of the sacrificed wall 50 in order to ensure that the gas barrier extends over the long possible area of the suppressed panel. 4. If the potion of the sheet extending down the wall is long, then the excess sheet will need to be folded for assembly. In this case the sheet 30 and the component 28 must be passed through aseptic sterilization prior to assembly in order to maintain the aseptic conditions. It is also possible to heat the sheet sufficiently to activate the folded and wrinkled portions to be fully engaged within the surface of the plastic component. The slightly large margin of a thin sheet 30 can be gently sealed from the interior of the recess 48.

The two caps produced in this medium can then be sterilized and passed to an aseptic line filling. It will be appreciated that due to the production process there are no remaining cracks in the inner surface 40 of the upper panel which may exist when a wad or a liner is adhered to the inner surface 40.

It could be noted that the liner 30 is not soldered from a conduit or neck of the container or bottle, but the bushing 2 is welded.

It will be appreciated that the term "fitting" refers to the position of the peripheral edge 32 relative to the final configuration of the top panel 4. In practice the sheet may have a welded surface of the remnants of the sacrificial panel 50. In the second covering described then, the edge 32 is fitted on the internal surface of the valve, while in the third covering the edge 32 and the complete sheet 30 is welded on the upper panel 4. In the fourth covering, the whole sheet is welded from the outer surface of the top panel 4. In addition it will be possible to clad the sheet on the ferrules and fit the edge on the edge 6. However it is not a preferred option as a leaf on the side wall of the ferrule can be accidentally peeled if the ferrules are applied by means of a tool that holds the side of the wall. The sheet in this position may also cover the typical flute provided on the outer surface of the edge 6 to facilitate the support of the sleeve 2 when it is open and closed. In all these covers the plastics of the sheet 30 is melted from the component of the cap 28.

VARIATIONS.

Caps 2 can also be produced without the valve 20, or with valves that can be as long as necessary to provide resellability against twisted bottlenecks. As illustrated in Figures 1 to 3, the valve 20 is an expandable cylindrical wall. As the depth of the valve increases there is a reach for the air to drag, which is drawn on the neck of the bottle when the cap is fitted. This can be avoided by closing the open end of the valve as described in more detail in the coverage of Figures 11, 14, and 15 below.

Sacrificial wall 50 may have other configurations which however will allow, in conjunction with a conveniently formed tool, to sacrifice the material for which it is formed in a covering of the edge 32 of the disc of the blade 40. A sharp wall, L-wall Sharp 50 or a thin wall bent over at the base may be possible.

SECOND COVERAGE In the second cover as illustrated in Figures 4 and 5, the sacrificial wall 50 is formed as part of the extension 54 of the valve 20 itself. The annular portion 54 is separated from the end of the valve by a reduced cross-sectional portion 56. In this coverage the recess 48 is the whole of the space within the valve 20. During production the part 54 is internally bent against an internal wall of the valve. the valve 20 as shown in Figure 5. After heating by the blade IHS 30 the edge 32 of the disc of the blade 30 engages the bushing and more specifically the wall of the valve 20.

THIRD COVERAGE In the third cover as illustrated in Figures 7 to 8, the bushing 2 is made of a component 28 and a second component or a valve plate 60 formed in the shape of the circular plate 62 carrying the valve 20.

The component 28 has a top panel 4 that is thinner than normal in order to define the barrier of the sheet receiving slot 48 that also receives the plate 62 of the second component 60. The slot 48 is defined by a wall 64 inside the top panel . A central part 66 of the upper panel 4 needs not to be present in order to reduce total weight in applications where the sheet itself has sufficient pressure retention capacity to maintain the structural integrity of the bushing 2. A central hole or opening 66 that exposes the sheet 30 and corresponds to the hole 68 in the plate 62 can be used to allow the consumer to puncture the cap with straw for the consumption of the containers without the opening of the cap. Where only weight saving is required the plate 62 can have a solid top. The central hole 66 may be longer than the one shown by providing therein sufficient groove 48 to maintain the blade of the disc 30 during assembly. The plate 62 can also have a central opening 68 when there is no corresponding opening in the upper panel.

In order to mount the third cover, the disc 30 is placed in the slot 48 and trapped in position by the plate 62. When the sheet is heated by heating induction the plastic material of the plate 62 and the wall 64 acts in the same way as the sacrificial wall of the component of the bushing 28.

FOURTH COVERAGE. In the coverage of Figures 9 and 10 the bushing 2 is made of an annular component of the bushing 2 and a circular valve plate 60 formed in the shape of a circular plate 62 carrying the valve 20. The sheet of the liner 30 is sits on top of plate 60.

The component 68 has a top panel 86 that defines a central hole or opening 88 that has a diameter smaller than the diameter of the plate 62. The bushing 2 is the part previously assembled for the part by the conduit or neck of the container or bottle . As shown in Figure 9, the plate 60 is mounted for the component 80 and held in place toward the base of the bushing 2. This can be joined by resistance in an inner facing the flange (not shown).

Since the plate 60 is at the base of the component of the bushing 28 when the bushing is engaged there is no significant volume of air that is entrained when the bushing 2 is fitted to the neck of a container or bottle. As in the cap 2 it is screwed into the neck of the plate 60 it moves upwards relative to the edge of the component 28. When the plate 60 abuts the upper panel 86 the sheet 30 again catches the panel 86. The cap is the induction heated to fit the sheet between the plate 62 and the upper panel 86 as shown in Figure 10.

VARIATIONS. As shown in Figures 11 to lc the sheet 30 can be fitted on one side of the open end of the valve 20 at the base of the plate 74. In Figure 1 la, the edge of the sheet 32 fits between the valve 20 and the wall sacrifices 50. The heated induction causes sacrificial wall material 50 to flow over the rim 32 by engaging it in the material of the valve plate 60. In Figures l lb and l lc the sheet extends out to the edge from the valve plate 62 or it can be wrapped around it.

These future variations reduce the amount of oxygen entrained when the bushing 2 is mounted on the neck as the small amount trapped in the space defined by the valve 20 is also eliminated.

FIFTH COVERAGE. In the coverage of Figures 12 and 13 the slit 48 is located on an external surface 70 of the upper panel 4 and is surrounded by a protruding sacrificial wall 50. The disc of the sheet 30 is dropped in the slit 48 and then heated by induction . The contact between the edge 32 of the sheet and the sacrificial wall 50 causes the material of the wall to flow over the edge sealing the disc 30 securely to the cap 70 of the cap so it can not be removed. The use of the gas barrier in the cap cap allows the sheet 30 to cover an even larger portion of the surface. This means that any gas that passes through the cap must pass along and long path inside the cap plastic to avoid the sheet. These results in very high levels of gas transmission.

While the edge 32 assembly is not essential in this coverage to avoid contamination of the containers, the liner 30 must be welded on the top panel 4. The fusion of the disc of the entire sheet to the panel will prevent the blade is moved during transport.

SIXTH AND SEVENTH COVERAGE. In the covers of Figures 14 and 15, a large plug 92 fills an entire internal space within the bushing 2 near this plug. This plug 92 also forms on the upper part the valve 20 to seal again an internal surface of the neck of the bottle or of the container for which the bushing is mounted.

In Figure 14 the component of the bushing 28 is molded to create a deep slot 90 in the top panel 4. The valve 20 is formed by an upper portion of side walls of the slot. A smaller part of the plug 92 may have a relative diameter reduction with the valve for insertion of the aid. The plug can also be sharpened.

The sheet 30 is seated in a slit 48 formed in the top panel 4 and is fitted as described in relation to the previous covers of Figures 12 and 13. The welding of the sheet 30 for the cap component 28 is carried out in a nitrogen environment so the cleft 90 is filled with this inert gas.

It will be appreciated that the component of the bushing 28 having a plug 92 can not be molded in one piece with a flat top panel. It is unacceptable to leave the slit exposed as it would attract dirt and turn it into pollution. Closing it by means of the blade disc 30, which seals in a nitrogen atmosphere, providing an elegant solution to this problem. On the other hand, the liner 30 is not directly exposed to the pressure of the content of the container but is supported by the structure of the plug. It is therefore possible to use a light, flexible aluminum foil for this purpose, as it is not under pressure.

In the coverage of Figure 15, the sheet 30 forms a closure for an open end of the plug 92 and is fitted and fused to the valve wall by means of a sacrificial wall 50 which is downwardly dependent on the valve wall. 20 to provide a groove in which the edge 32 of the sheet can previously feed to be melted in the groove by means of induction of heat sealant. The vacuum inside plug 92 is filled with nitrogen or another inert atmosphere.

In both coverages the application of the cap to the neck of the bottle introduces the smallest possible quantity of entrained air. Therefore this bushing retains as much as possible of the inert atmosphere in the neck space on the contents as possible.

VARIATIONS. Rather than simply extending through the lid of the deep slit 90 the sheet 30 can be used to align the slit 90. The slit can be left cast, but is preferably mounted with another decorative material to avoid trapping the dirt and representing a hygienic risk. Alternatively a sheet may be placed through the deep slot 90 and the interior lined with EVOH or other similar plastic materials from the gas barrier.

GENERAL VARIATIONS. Chemical cleaners may be added to the material which the cap is molded or added to the sheet membrane or cleaner layer may be applied to the outer surface of the cap 2. It is also desirable to use oxygen cleaning materials in the parts of the bushing touching or closing for the product for example on an inner surface of the plug end 92.

It will be appreciated that the constructions described allow the production of a bushing with an effective gas barrier that also has a long and functional valve 20 suitable for carbonated beverages sealing.

Claims

CLAIMS AMENDED. (Received by the International Office on August 22, 2005 (08.22.05), original demands 1-25 replaced by new demands 1-27 (4 pages))

1. A collapsible plastic bushing (2) having an upper panel (4), a bank (6) and an aluminum element coated with plastic (30) attached to the bushing (2) to provide a gas barrier inhibiting gas flow through the bushing, for example that the peripheral aluminum edge of the aluminum element can not come into contact with the contents of the container closed by the bushing in use; characterized in that the coated aluminum element is quite thin to be flexible and has the peripheral edge fused into the cap material.

A collapsible plastic cap (2) having an upper panel (4) and a border (6) wherein a liner of the plastic coated aluminum sheet (30) has a peripheral edge on one surface (40, 70) of the cap (2).

A bushing (2) as claimed in claim 1 or 2, wherein the edge of the sheet (32) is fitted and fused to an internal surface (40) in the lid of the panel (4).

4. A bushing (2) as claimed in claim 1 or 2, wherein the sheet (30) is fused to an external surface (70) of the edge (6) or upper panel (4) of the bushing (2).

5. A bushing (2) as claimed in any of the preceding claims, wherein an opening (66) is formed in the upper panel (4).

6. A bushing (2) as claimed in any of the preceding claims, wherein a valve (20), adapted to fit inside and seal from new an internal wall of a neck of a container for which the bush is adjusted, depends on the upper panel (4).

7. A bushing (2) as claimed in claim 6, wherein the valve (20) is provided on a plate (62), which catches the line plotter (30) on an inner surface of the upper panel (4).

8. A bushing (2) as claimed in claim 7, wherein the plate (62) has an opening (68) which cooperates with a corresponding opening (66) in the upper panel to allow the sheet to be punched for access to the contents of a container closed by the bushing in use.

9. A bushing (2) as claimed in claim 6, on the edge of the sheet (32) is embedded and fused within the inner surface of the valve (20).

10. A bushing (2) as claimed in any of claims 6 to 9, wherein a closed plug (92) is formed within the bushing to substantially fill a vacuum within the bushing and to define the valve.

11. A bushing (2) as claimed in claim 10, wherein the sheet liner (30) forms or protects the external or internal end face of the plug.

12. A bushing (2) as claimed in claim 10, inside the socket (92) is defined by a recess (90) aligned with a liner.

13. A bushing (2) as claimed in claim 10 or 11, inside the plug (92) is aligned with EVOH or other gas barriers of similar plastic materials.

14. A resealable plastic cap (2) having a top panel (4), a margin (6), a gas barrier (30) to inhibit the flow of gas through the cap (2), and a closed plug (92) substantially filling a vacuum within the bushing to define a valve (20) adapted to assemble within and seal against an inner wall of the neck of a container to which the bushing is assembled, characterized in that the gas barrier is provided by means of aluminum foil coated with plastic (30) fused with plastic material of the cap.

15. A bushing (2) as claimed in any of claims 6 to 14, within the plastic coated aluminum foil (30) extended across the total width of the valve.

16. A bushing (2) as claimed in claim 15, inside the aluminum foil that also extends up or under the valve wall.

17. A bushing (2) as claimed in any of the previous claims, where the margin (6) is screwed.

18. A bushing (2) as claimed in any of the previous claims, wherein the oxygen scavenging materials are used in parts of the bushing or near a product in a container in which the bushing is fitted in use.

19. A mounting of a bushing as claimed in any of the preceding claims and a glass, plastic, steel or aluminum bottle, jar or any other container.

20. A mounting of a bushing as claimed in any of claims 1 to 8 and a container made of cardboard or composite material.

21. A mounting of a bushing as claimed in any of claims 1 to 18 and a thermoformed container.

22. A plastic component (28) for use in the manufacture of a bushing (2) as claimed in any of claims 1 to 13, wherein a The annular wall (20.50) extends the upper panel (4) for the purpose of defining a slit (48) for receiving the sheet plotter (30).

23. A plastic component (28) as claimed in 1 claim 22, wherein the diameter of the sheet liner is smaller than the neck of a bottle or container for which the cap is to be adjusted in use.

24. A plastic component as claimed in claim 22, wherein the wall (20, 50) has an intermediate, reduced cross section (56) in order to allow a lower part (54) of the wall to be bent back toward the top panel in order to retain the peripheral edge (32) of the sheet liner during production.

25. A method of producing a bushing (2) for plastic components 828) by compressing an upper panel (4) surrounded by a bank (6), a slit receiving (48) for a leaf barrier, and a SACRIFICAL wall (50), the method comprising the steps of placing a leaf barrier (30) in the slit (48) and heating the wall (50) to melt the plastic material of the wall in order to fit an edge (32) of the sheet (30) in the bushing (2).

26. A method as claimed in claim 25, wherein the step of the heating comprises the induction heating the sheet (30) to melt the wall (50).

27. A method as claimed in claim 25 or 26, wherein the sheet (30) is large and when placed in the slit (48) has a peripheral edge (32) pressed again an internal surface of the slit ( 48).