AU2022224757A1

AU2022224757A1 - Sample Port for Packaging

Info

Publication number: AU2022224757A1
Application number: AU2022224757A
Authority: AU
Inventors: Michael John KERR; John Cameron Sadler
Original assignee: Jaytech Industries Ltd
Current assignee: Jaytech Industries Ltd
Priority date: 2021-09-06
Filing date: 2022-08-31
Publication date: 2023-03-23

Abstract

A sample port which includes a collar which provides a flange for permanently securing the sample port into a container, a first side of the collar having a gas permeable filter secured thereto; a second side of the collar providing an aperture which extends 5 between the first and second sides of the collar and gives access to the side of the filter furthest from the container; the sample port further includes means for closing said aperture. 12 1/6 12 10 A A Fig.1 13 15 13 Fig.2 11a 11 19 113 18 16 Fig.3 1 11a

Description

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SAMPLE PORT FOR PACKAGING

Technical Field The present invention relates to a port for packaging, in particular bulk packaging, which allows sampling of gases contained or entrained within the packaging.

Background Art It is common practice to pack goods in gas-impervious protective packaging made of heavy plastics sheet formed into bags. The goods packed in this way may be powders (for example, milk powder, fishmeal powder) or small solids (for example, dates, raisins) or larger solids. Many goods, whether food stuffs or not, preferably are not packed surrounded by air for prolonged periods:- the oxygen in the air will gradually oxidise many food stuffs, and water vapour in the air can encourage the formation of mould, or oxidation in the case of metal components.

To avoid, or at least reduce, these problems, it has become increasingly common practice to flush air out of the goods to be packed using an inert gas such as nitrogen. This is especially the case where goods are to be packed in bulk and shipped and/or stored for relatively long periods.

Further, for long-term storage of bulk packed goods where insect contamination or bacterial growth is likely to be a problem, it may be advantageous to flush air out of the goods using a gas which inhibits bacterial growth and/or kills any insects entrained with the goods.

A wide range of gas flushing/purging techniques is known.

To ensure that the gas exchange has been completed to a satisfactory level, it is necessary to sample the gas entrained within the pack. Also, once a bulk pack has been sealed, excess gas frequently accumulates at the top of the pack ('headspace gas'), making the top of the pack bulge. This makes stacking the sealed packs difficult or even impossible, and it is desirable to be able to vent any excess gas from the top of the pack, without actually opening the pack.

Providing a pack with a closable vent which communicates directly with the interior of the pack gives very poor results in practice, because it is virtually impossible to remove excess gas or sample the gas at the top of the pack without also losing some of the pack contents; this is especially the case if the pack contains a powder.

It is known to provide a pack with a filter port welded into the top of the pack. Known filter ports provide a long tubular filter which extends down into the pack. The filter is made of a material which allows gas to pass through into the interior of the filter, but which prevents even a fine powder from entering the filter.

Typically, the filter is about 10 cm long. The lower end of the filter is closed. The upper end of the filter is secured into a collar welded to the exterior of the pack; the collar also supports a manually openable tap fitting or an externally screw threaded fitting provided with a corresponding screw threaded cap.

To sample the gas at the top of the pack, the tap can be opened or the screw threaded cap removed, allowing the gas within the filter to be sampled. Similarly, excess gas can be removed if necessary.

Fittings of this type have been used for many years, but they suffer from the disadvantages of being relatively bulky, slow to operate, and prone to operator error. For example, the port fitted with a tap must be manually turned to the correct position, and if inadvertently left in the wrong position, it will continue to allow gas to leak out of the pack and also allow air to leak back into the pack. The port fitted with the screw threaded top is comparatively slow to use because the cap has to be un-screwed and then screwed back, and if it is not properly screwed home, the pack will leak or air will leak back into the pack.

A lower profile fitting also is available, but this has the drawback of a comparatively large internal volume and also is constructed so that it requires a comparatively large amount of gas to be withdrawn before a sample of the headspace gas can be obtained.

A further drawback is that the existing fittings provide only a comparatively wide bore fitting for removing a gas sample, and do not facilitate taking a small gas sample only.

Disclosure of Invention An object of the present invention is the provision of a sample port which overcomes, or reduces, at least some of the above described disadvantages.

The present invention provides a sample port which includes a collar which provides a flange for permanently securing the sample port into a container, a first side of the collar having a gas permeable filter secured thereto; a second side of the collar providing an aperture which extends between the first and second sides of the collar and gives access to the side of the filter furthest from the container; the sample port further includes means for closing said aperture.

Preferably, said means for closing said aperture includes a removable cap.

Preferably also, said cap incorporates a protruding boss which is dimensioned and arranged to be insertable within said aperture to provide a removable gas tight seal.

Preferably also, said boss is provided with a single use seal which provides a gas tight seal until penetrated by a sampling needle.

Preferably also, said cap is tethered to the collar.

Preferably also, said cap incorporates a self-sealing septum through which a sampling needle can be inserted.

In one embodiment, said cap is provided with a transparent portion, the underside of which carries a sensing dot of known type, which changes colour when in contact with a selected gas.

Preferably, said filter provides an area immediately below the collar of the port in which in use gases from the pack can accumulate.

Said filter may be a shape selected from the group consisting of:- a dome; a flattened dome; a cylinder.

Preferably, the port further includes a flap valve which is permanently secured across the interior of the filter, immediately below said aperture.

The present invention has been developed with particular reference to bulk packs of milk powder, and will be described with reference to that application. However, it will be appreciated that the present invention also may be used with flexible or rigid packs of a wide range of materials and sizes, for a wide range of contents.

Brief Description of Drawings By way of example only, a preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which:

Figure 1 is a plan view of a sample port in accordance with a first embodiment of the present invention;

Figure 2 is a side view of the sample port of Figure 1;

Figure 3 is a section on line A - A of Figure 1, on a larger scale;

Figure 4 is a partial section of the sample port of Figure 1 showing the insertion of a gas sampling/gas exchange tube;

Figure 5 is a view similar to Figure 3, but of a second embodiment of the invention;

Figure 6 is a view similar to Figure 3, but of a third embodiment of the invention;

Figure 7 is a view similar to Figure 3, but of a fourth embodiment of the invention;

Figure 8 is a side view of a fifth embodiment of the invention;

Figure 9 is a longitudinal section through a sixth embodiment of the invention;

Figure 9a is a plan view of a detail of Figure 9; and

Figure 10 is a longitudinal section through a variant of the embodiment of Figure 9, with the cap closed.

Best Mode for Carrying Out the Invention Referring to Figures 1-4, a first embodiment of the present invention provides a sample port 10 which includes a filter 11 (not visible in Figure 1) the upper edge of which is attached (e.g. by welding or gluing) to a collar 12 which incorporates a flange 13 and a central aperture 14. A removable tethered cap 15 is anchored to the surface of the collar 12 opposite to the filter 11.

The filter 11 may be made of any of a range of suitable materials:- its function is to allow gases to pass from the pack into the interior of the filter, without allowing the contents of the pack (e.g. milk powder) to pass into the filter. Obviously, if the sample port is to be used with packs containing food stuffs, then all of the materials of which the sample port is made, including the filter, must be food safe material. Typically, the filter 11 would be made of sintered high density polythene powder.

The filter 11 is depicted in figures 1-4 as a dome shape with a first end 11a closed and flattened, to provide the sample port with a low profile. The second, opposite end 11b of the filter is open and is circular in plan view. The second end 11b is attached (e.g. welded or glued) into a channel 16 formed around the collar 12, to form a dust tight fit between the filter and the collar.

The collar 12, the flange 13, and the aperture 14 all are circular in plan. Essentially, the collar 12 provides a one-piece connection between the interior and exterior of the pack, once the flange 13 is secured onto the perimeter of a hole formed in the pack material.

The aperture 14 extends between the side of the collar adjacent the filter 11 and the opposite side of the collar. The cap 15 is circular in plan and is formed with a central boss 17, the free end 18 of which is tapered. The outer diameter of the boss 17 is sized to be a tight fit/interference fit in the aperture 14 so that when the cap 15 is in place, the boss 17 provides a substantially gas tight seal for the aperture 14. The tapering 18 on the free end of the cap helps to guide the boss 17 into the aperture 14.

The cap 15 is formed with a short flexible tether 19 at one edge; this tether is secured to the adjacent surface of the collar 12, to retain the cap when it has been disengaged from the aperture 14. A lifting tab 20 is formed on the edge of the cap opposite to the tether 19, to assist in levering the boss 17 out of engagement with the aperture 14. A barcode or QR code (not shown) may be stamped on the upper surface of the cap for tracking purposes. This makes it possible to track each bag from packing to unloading, simply by using a code reader, e.g. when the headspace gas is sampled.

Figure 4 shows a partial section through the sample port of Figures 1-3 with the flange 13 welded into the perimeter of an aperture cut in the top of a plastic bulk pack 21, only part of which is shown. As shown in Figure 4, to sample the gas in the top of the pack 21, which has passed through the filter 11 into the inner space 22 of the port, the cap 15 is opened to the position shown in Figure 4, and a sampling tube 22a is inserted through the aperture 14. This enables a sample of the gas collected in the space 22 to be extracted. Once the gas sample has been taken, the cap 15 is replaced to reseal the sample port.

The above described sample port is the simplest version of the port of the present invention, and may be varied in a number of ways, to suit particular applications.

Firstly, the size of the filter 11 may be made larger or smaller, to suit the size of the pack to which it is to be fitted and the size of the gas sample required. For some applications, it may be necessary or desirable to use the sample port to move a comparatively large volume of gas from the pack, either for the purpose of applying vacuum to the pack or for large-scale sampling or even gas exchange. For this, it is advantageous to provide a larger filter.

If only a very small gas sample is required, then the filter may be correspondingly reduced in size. This is advantageous in applications where the empty packs need to be packed together as flat as possible.

Secondly, the shape of the filter may be altered e.g. a full dome shape, a cylindrical shape or a low profile short cylinder.

Thirdly, the port may be adapted to provide both facilities for removal of any gas from the top of the pack, and sampling of these gases, as described with reference to Figure 4 above, and also provide for sampling of the gases in the filter space 22 using a sampling needle. This is provided for by mounting a rubber septum 23 in the centre of the cap 15, as shown in Figure 5. The septum 23 is made of a known type of self sealing rubber compound; this allows a hollow sampling needle 24 to be pushed through the septum 23 to sample the gas in the space 22 of the filter 11 without removing the cap 15. Once the sampling needle 24 has been withdrawn, the material of which the septum 23 is made self seals, preventing any leaking of air into the port.

It is known to provide packs with stuck on patches which incorporate a self sealing septum, but with existing designs these are stuck direct onto the pack wall, with the result that when the sampling needle is pushed through the septum, the particles of the septum material which often are displaced by the needle, enter directly into the pack contents. With the design shown in Figure 5, any particles of the septum material which are displaced by the sampling needle are retained inside the filter 11, and cannot contaminate the pack contents.

Because the septum 23 is self sealing, multiple samples can be taken if necessary. In addition, if it is necessary to use the port to remove a large volume of gas e.g. to vent gases which have accumulated at the top of the pack, then the cap 15 is opened and a tube pushed through the aperture 14 as described with reference to Figure 4 above.

Fourthly, the port may be modified as shown in Figure 6. This modification is useful for applications where only a single sample of the gases in the space 22 is required, just before the pack is to be opened. In this modification, the cap 15 is formed with a central hole 25 through which a sampling needle 24 can be inserted, and the portion of the boss 17 which lies within the space 22 when the boss 17 is fully engaged with the aperture 14 is sealed by a gas tight film 26. The film 26 is not self sealing, so once the film 26 has been pierced by the sampling needle 24, the pack must be used more or less immediately, because the port is no longer gas tight.

A fifth modification is shown in Figure 7. In this modification, the central portion of the cap 15 is provided with a transparent portion 26, the underside of which carries a sensing dot 27 of a substance which changes properties (e.g. colour) when in contact with a selected gas (e.g. oxygen). Sensing dots of this type are commercially available. Use of a sensing dots of this type would enable each pack to be "read" by a sensor recording the colour of the dot, without opening the cap 15 at all, although of course larger gas samples could be taken and or excess gas could be removed as described above, by lifting the cap 15.

For applications where it is necessary to identify the headspace gas, but not to extract a sample of it, it is envisaged that a very small port as shown in Figure 8 could be used. In this embodiment, an annulus of filter material 30 is secured inside a collar 31 which incorporates a flange 32 for securing to the edges of an aperture in the pack. The collar 31 is closed and is made of transparent material so that a reader on the outside of the port can read a sensor dot 33 which is supported on the side of the filter material furthest from the pack. This port has a very low profile (typically less than five millimetres in height).

A sixth modification is shown in Figures 9-10. The basic construction of the sample port is as shown in Figures 1-4 unless otherwise specified, and the same reference numerals are used where the components correspond. The major difference between the first and the sixth embodiment is the addition of a flap valve 40 which is permanently secured across the interior of the filter 11, immediately below the aperture 14.

As shown in Figure 9A, the flap valve 40 consists of a disc of resilient sheet material formed with two intersecting slits 41, such that downward pressure on the centre of the flap valve 40 (as shown in Figure 9) spreads the flaps of the valve apart and allows the insertion of a gas probe 42. The gas probe 42 can then be used to take a sample of the gas in the inner space 22 of the filter 11.

When the gas probe 42 is withdrawn, the flaps of the valve 40 snap back together, so that the space 22 (and thus the bulk pack 21) is sealed as soon as the probe 42 is withdrawn. The addition of the flap valve 40 provides extra security against gases to be sampled being lost from the space 22 of the port as soon the cap 15 is opened, and also security against atmospheric gases entering the space 22 when the cap is opened.

A flap valve 40 as described above may be added to any of the embodiments shown in Figures 1-7.

As shown in Figure 10, the cap 15 may also be modified to accommodate fine needle sampling as described with reference to Figure 5, by mounting a rubber septum 43 in the centre of the cap15, allowing a sampling needle to be inserted through the septum 43 and then through the flaps of the flap valve 40, to take a sample of the gases in the space 22. As described with reference to Figure 5, the septum 43 is made of a known type of self-sealing rubber compound, so that once the sampling needle has been withdrawn, the septum self heals.

All of the examples of the invention described above have shown sample ports which are circular in plan view, however, it will be appreciated that the sample ports may have any of a wide range of shapes.

The proportions and dimensions of the sample port will of course be selected to suit the pack to which the port is fitted. By way of example, for a bulk pack which is approximately 5 metres in circumference, a port of the following dimensions has been found suitable: • outside diameter 55 millimetres • overall height 23 millimetres • aperture 14 - diameter 14 millimetres • filter - diameter 30 millimetres, height 17 millimetres.

Claims

1. A sample port which includes a collar which provides a flange for permanently securing the sample port into a container, a first side of the collar having a gas permeable filter secured thereto; a second side of the collar providing an aperture which extends between the first and second sides of the collar and gives access to the side of the filter furthest from the container; the sample port further includes means for closing said aperture.

2. The sample port as claimed in Claim 1, wherein said means for closing said aperture includes a removable cap.

3. The sample port as claimed in Claim 2, wherein said cap incorporates a protruding boss which is dimensioned and arranged to be insertable within said aperture to provide a removable gas tight seal.

4. The sample port as claimed in Claim 3, wherein said boss is provided with a single use seal which provides a gas tight seal until penetrated by a sampling needle.

5. The sample port as claimed in any one of Claims 2-4, wherein said cap is tethered to the collar.

6. The sample port as claimed in any one of Claims 2-5, wherein said cap incorporates a self-sealing septum through which a sampling needle can be inserted.

7. The sample port as claimed in any one of Claims 2-6, wherein said cap is provided with a transparent portion, the underside of which carries a sensing dot of known type, which changes colour when in contact with a selected gas.

8. The sample port as claimed in any one of the preceding claims, wherein said filter provides an area immediately below the collar of the port in which in use gases from the pack can accumulate.

9. The sample port as claimed in Claim 8, wherein said filter is in a shape selected from the group consisting of: a dome; a flattened dome; a cylinder.

10. The sample port as claimed in any one of the preceding claims, further including a flap valve which is permanently secured across the interior of the filter, immediately below said aperture.

11. A sample port which includes a collar which provides a flange for permanently securing the sample port into a container, a first side of the collar having a gas permeable filter secured thereto; a sensing dot of known type, which changes colour when in contact with a selected gas, is mounted on the side of the gas permeable filter closest to the collar; and at least the portion of the collar which overlies said sensing dot is transparent.

12. The sample port as claimed in Claim 11, wherein the collar and the flange are integrally formed.

13. The sample port as claimed in Claim 11 or Claim 12, wherein the overall height of the port is less than 5 mm.