WO2008046419A1

WO2008046419A1 - A device for the use in permeability testing of containers

Info

Publication number: WO2008046419A1
Application number: PCT/DK2006/050061
Authority: WO
Inventors: Poul Fogh; Thomas Clausen; Kenneth Verner Hansen
Original assignee: PBI DANSENSOR AS
Current assignee: PBI DANSENSOR AS
Priority date: 2006-10-18
Filing date: 2006-10-18
Publication date: 2008-04-24
Anticipated expiration: 2009-04-18

Abstract

A device (1) for the use in permeability testing of containers, such as bottles and jars having a thread in the vicinity of their opening. The device comprises a cup-shaped member with a bottom and an upright wall surrounding said bottom, so as to define a generally cylindrical bore (5). The upright wall comprises a thread facing the interior of said cup-shaped member. The bottom comprises at least one through bore (11, 13; 12, 14) sealed by a septum (18, 19).

Description

A device for the use in permeability testing of containers

The present invention relates to a device for the use in permeability testing of containers, in particular, but not exclusively jars, bottles or the like made of polymer materials, and having a thread in the vicinity of the opening.

In the industry of food packaging and packaging of medical supplies there is a need for gas permeability testing of packages. If the gas permeability of a food packaging or a packaging of medical supplies is too high, ingress of oxygen may spoil the content. Also, for carbonated drinks the carbon dioxide may escape through the wall of the container, such as a plastic bottle, which over term also ruins the drink. Knowledge about the permeability of the packaging is therefore of interest, e.g. in order to assess shelf life of the products. One way of testing the permeability of such packaging is described in WO-A-03/060485. Here the atmospheric air is flushed from the packaging with a gas or gas mixture such as nitrogen. After flushing, the packaging is sealed and left for an extended period of time, in order to allow a measuring gas, such as oxygen to penetrate the into the con- tainer through the permeable wall. During this extended period of time, the packaging may also be passed through typical heating and cooling cycles, e.g. to simulate the lifetime of the packaging in actual use. By measurement of the concentration of the measuring gas at suitable intervals during the extended period of time the permeability can be de- termined.

In order to allow withdrawal of samples from the interior of the packaging while keeping the interior sealed, WO-A-03/060485 makes the suggestion to use a hollow bolt penetrating a flexible packaging and sealed against the packaging by means of gaskets and retaining nuts. The end of the hollow bolt protruding from the packaging is closed by means of an end nut containing a septum. No suggestions are made in WO-A-03/060485 in respect of sealing a rigid packaging such as a plastic bottle or jar. On this background it is the object of the present invention to present a device for sealing containers, in particular, but not exclusively rigid containers such as jars, bottles or the like made of polymer materials, in a manner conveniently allowing testing thereof as described above.

According to the present invention, this object is achieved by a device for the use in permeability testing of containers, such as bottles and jars having a thread in the vicinity of their opening, said device comprising a cup-shaped member with a bottom and an upright wall sur- rounding said bottom, so as to define a generally cylindrical bore, where said upright wall comprises a thread facing the interior of said cup- shaped member, and where said bottom comprises a through bore sealed by a septum.

Thereby it becomes possible to seal a container, such as a bottle or a jar, in a simple and convenient manner, while at the same time allowing withdrawal of samples from the interior of the container at convenient intervals without breaking the sealing.

According to a preferred embodiment of the invention said septum is exchangeable. The use of an interchangeable septum prolongs the life of the device, as a septum worn out by repeated penetrations by syringes may be replaced with a new one.

According to another preferred embodiment of the invention a sealing means is arranged in connection with the bottom. Placing a sealing, preferably an o-ring, in connection with the bottom of the device improves the sealing, and allows the device to be used directly on a container, in particular a jar or a bottle, without having first to prepare the opening of the bottle or jar for sealing.

According to a further preferred embodiment said bottom comprises a further through bore sealed by a septum. Having a further through bore facilitates the insertion of syringes in their correct location, when more than one syringe has to be inserted into the device at the same time, as would be the case during e.g. the flushing of atmospheric air from the container. This is particularly relevant when according to yet a further preferred embodiment a tubular member is arranged in conjunction with said further bore and extending into said cylindrical bore. The use of such a tubular member allows the flushing gas to be introduced deep into the container, e.g. near the bottom thereof, so as to allow a good flushing, when the excess air is extracted at the sealed opening of the container.

According to yet another preferred embodiment said tubular member extends into and beyond said tubular bore. Thereby the tubular member can be provided as a single piece element adapted in length to the depth of a container to be tested.

According to a further embodiment, said tubular member is adapted for receiving the end of a further tubular member. This allows for easy adaptation of the device to the depth of the container to be tested by simple replacement of the further tubular member.

This is particularly advantageous if according yet a further embodiment, wherein said further tubular member is made of a polymer material. Such a further tubular member made of a polymer material is easy to cut to length, and if flexible is also easy to fit on the tubular member. Moreover such a flexible polymer tube is easily fitted inside the container without having to cut the length very accurately.

According to another preferred embodiment tubular member is press-fit into said further bore. This is a convenient method of fitting such a tube, as compared to e.g. a screw and thread connection, solder- ing, or machining thereof in one piece with the bottom.

According to another preferred embodiment, the sealing member is an o-ring located in a circular groove in said bottom. Such a sealing is easily replaced when it wears out, thus prolonging the overall life of the device. According to yet another preferred embodiment said device comprises a bottom forming member, forming the bottom of said cup- shaped member, and a septum retaining member, where said septum is clamped between said retaining member and said bottom forming mem- ber. Clamping the septum is a very convenient way of retaining it, while at the same time allowing for easy replacement thereof.

According to a further preferred embodiment, said cup-shaped member comprises an assembly of said bottom forming member and a wall forming members forming said upright wall. Making the bottom member and the as separate pieces is advantageous from a manufacturing point of view, yet ensures sufficient sealing properties of the device according to the invention.

According to another preferred embodiment at least one of said bottom forming member, said retaining member and said upright wall is made of metal. Metal, such as brass, is impermeable and thus ensures good sealing properties over the prolonged testing of containers. Moreover metal is rugged and allows the device as such to be used and reused numerous times, as long as the septum and sealing means are re- placed when worn.

According to a further preferred embodiment, said thread facing the interior of said cup-shaped member is a self-cutting thread. This embodiment allows the use with containers which do not have a thread in the vicinity of the opening. According to yet a further preferred embodiment, said device comprises an oxygen scavenger. This allows for oxygen measure at very low concentrations of oxygen in the container, thus allowing a precise determination of the ingress of oxygen from the surrounding atmosphere, which again leads to a precise permeability measurement. In a particular preferred embodiment, said oxygen scavenger is provided on the further tubular member. This is advantageous as the further tubular member is a readily interchangeable part. Thus for the reuse of the device in a new test, it is merely necessary to replace the tubular member with a new one, provided with a pristine oxygen scav- enger.

The present invention will now be described in greater detail based on a non-limiting exemplary embodiment as illustrated on the drawing. On the drawing, fig. 1 shows an exploded view of a device according to the invention.

In fig. 1 is shown the device 1 according to the invention for the use in permeability testing of containers, such as bottles and jars (not shown). The device 1 comprises an assembly of a bottom forming member 2 and a wall forming member 3. The wall forming member 3 forms an upright wall 4. The wall forming member 3 is preferably a generally cylindrical member with a central through bore 5. The internal wall of the wall forming member towards the central trough bore has a thread 6, matching the external tread of a container such as a jar or a bottle. Such external treads are generally standardized, and one and the same thread 6 in the internal wall will match a large number of containers, e.g. bottles for soft drinks, irrespective of the size bottles. In alternative embodiment, however the thread 6 is a self-cutting thread, engaging the vicinity of the opening of the container, thus allowing the device to be used with a wide range of containers not having an external thread. The assembly of the bottom forming member and the wall forming member define a generally cup-shaped member. The assembly of the bottom forming member 2 and the wall forming member 3 is preferably held to- gether by means of a suitable number of screws 7, through appropriate through holes 8 in the bottom forming member 2. The skilled person will however realize that the bottom forming member 2 and the wall forming member 3 could be joined by other means, or that the cup-shaped member could even be manufactured as a single piece. Both the wall forming member 3 and the bottom forming member 2 are preferably made of metal, such as brass.

In the surface of the bottom forming member 2, a circular groove or recess 9, for accommodating an o-ring of a resilient material, is provided. The o-ring 10 provides a replaceable sealing means for seal- ing against the opening of the container to be tested.

In the bottom forming member there is also provided two through bores 11, 12, through which syringes may be passed. These two through bores 11, 12 register with two bores 13, 14 in a clamping member 15. Around each of the two through bores 13, 14 in the clamping member 15, there is provided a circular recess 16, 17, for accommodating a respective septum member, in the form of preferably self-adhesive circular disks 18, 19. In this respect it should be noted that instead of two circular recesses and two disks 18, 19, a single larger disk and a single larger recess surrounding the two through bores could be used. Similar a single larger bore big enough to accommodate several syringes could be used instead of the two bores 13, 14 shown. In case of only a single bore, that single bore would be surrounded by a single recess, accommodating a single septum member. The clamping member 15 is fixed to the bottom member 3 by means of a number of screws 20 through appropriate bores 21 in the clamping member 15 into additional bores 22 in the bottom forming member 2. The septum members 18, 19 are readily replaceable after removal of the screws 20 and the clamping member 15. Finally it should be noted that recesses, corresponding to the recesses 16, 17 could be provided in the bottom forming member 2. The through bore 11 in the bottom forming member 2 extends into a tubular member 23. In the preferred embodiment the tubular member 23 is press fitted into the through bore 11, but the skilled person will realize that the tubular member 23 could instead be fitted into the bore by means of a thread engaging a matching thread in the bore 11, that the tubular 23 member could be glued or soldered to the surface of the bottom forming member 2, or that the tubular member 23 could be formed integrally with the bottom forming member 2. The tubular member 23 is preferably stepped in diameter to avoid over- insertion into the through bore 11. In the illustrated embodiment the tubular member 23 is relatively short extending only into the cup-shaped member. However, the skilled person would realize that the tubular member could not only extend into but also beyond the cup-shaped member, so as to extend deeply into a container, which is sealed with the device according to the invention. Instead of using a long tube, it is however preferred to use a short tube, as illustrated, to which is then attached a hose or flexible tube 24. The flexible tube will in that case extend deeply into the container sealed with the device according to the invention. Having a long tube 24 or an attached flexible tube allows the container to be flushed effectively, by insertion of the flushing gas at the far end of the container, and extracting the excess air in the vicinity of the bore 12. The flexible tube 24 is preferably of a flexible polymer material such as plastic or silicone. Such a material is easily attached to the tubular member 23, and easily cut to an appropriate length. Moreover as it is flexible 24 the accuracy in cutting it to length need not be high, as any excess length will find place in the container.

However, instead of the flexible tube 24 a metal tube may be used. In that case the tubular member 23 is preferably provided with a thread, be it internally or externally. The metal tube would be provided with a matching external or internal tread as the case may be.

Preferably, the flexible tube 24 or the metal tube is provided with an oxygen scavenger. The actual type of oxygen scavenger is not of importance to the invention, and is a mere matter of appropriate selec- tion by the person skilled in the art. Thus use of an oxygen scavenger will allow the oxygen content in the container to be reduced to an absolute minimum before the permeability test is initiated. Having, the oxygen scavenger provided on exchangeable parts such as the flexible tube 24 or the metal tube is advantageous, because only this part then, needs to be replaced for new permeability tests using the same overall device. Evidently, this does not exclude that the oxygen scavenger is provided elsewhere on the device, as long at it gets in contact with the interior of the container to be tested.

With the present invention there is provided a convenient, reus- able test cap for containers. The skilled person will understand that the explanation above relates to an exemplified embodiment, and that numerous variations are possible without deviating from the scope of the invention, as defined in the claims.

Claims

P A T E N T C L A I M S

1. A device for the use in permeability testing of containers, preferably such as bottles and jars having a thread in the vicinity of their opening, said device comprising a cup-shaped member with a bottom and an upright wall surrounding said bottom, so as to define a generally cylindrical bore, where said upright wall comprises a thread facing the interior of said cup-shaped member, and where said bottom comprises a through bore sealed by a septum.

2. A device according to claim 1, wherein said septum is exchangeable.

3. A device according to any one of the preceding claims, whe- rein a sealing means is arranged in connection with the bottom.

4. A device according to any one of the preceding claims, wherein said bottom comprises a further through bore sealed by a septum.

5. A device according to claim 4, wherein a tubular member is arranged in conjunction with said further bore and extending into said cylindrical bore.

6. A device according to claim 5, wherein said tubular member extends into and beyond said tubular bore.

7. A device according to claim 4 or 5, wherein said tubular member is press-fit into said further bore.

8. A device according to claim 5, 6 or 7, wherein said tubular member is adapted for receiving the end of a further tubular member.

9. A device according to claim 8, wherein said further tubular member is made of a polymer material.

10. A device according to claim 8, wherein said tubular member comprises a thread, and wherein said further tubular member is a metal tube comprising a matching thread.

11. A device according to any one of claims 3 to 10, wherein said sealing member is an o-ring located in a circular groove in said bottom.

12. A device according to any one of the preceding claims, wherein said device comprises a bottom forming member, forming the bottom of said cup-shaped member, and a septum retaining member, where said septum is clamped between said retaining member and said bottom forming member.

13. A device according to any one of the preceding claims, wherein said cup-shaped member comprises an assembly of said bottom forming member and a wall forming members forming said upright wall.

14. A device according to any one of the preceding claims wherein at least one of said bottom forming member, said retaining member and said upright wall is made of metal.

15. A device according to any one of the preceding claims, wherein said thread facing the interior of said cup-shaped member is a self-cutting thread.

16. A device according to any one of the preceding claims, wherein said device comprises an oxygen scavenger.

17. A device according to any one of the preceding claims wherein said oxygen scavenger is provided on the further tubular member.