WO2002059013A1

WO2002059013A1 - An analysable pacage, an analysis system and a method for analysing a packed product

Info

Publication number: WO2002059013A1
Application number: PCT/GB2002/000291
Authority: WO
Inventors: Andreas Manz
Original assignee: Casect Limited
Priority date: 2001-01-24
Filing date: 2002-01-22
Publication date: 2002-08-01
Also published as: GB0101835D0; EP1365971A1

Abstract

An analysable package, comprising: a sealable container (3; 23) for containing a degradable product (5; 25); and first and second electrode members (9, 11; 27, 29) each including a conductive electrode (9a, 11a; 27a, 29a), which electrodes (9a, 11a; 27a, 29a) are spaced and define a plasma-generation region (13; 29) in the container (3; 23) in which a plasma is in use generated on connecting a power supply (41) to the electrodes (9a, 11a; 23a, 23b).

Description

AN ANALYSABLE PACKAGE, AN ANALYSIS SYSTEM AND METHOD FORANALYSING A PACKED PRODUCT

The present invention relates to an analysable package for containing a degradable product, an analysis system for analysing a packaged product, and a method of analysing a packaged product.

There are many packaged products, for example, foodstuffs, such as meat, fish and poultry, and pharmaceuticals, which can degrade with time and consequently have to be assigned a use by date in order to avoid the possibility of any harmful effect to a user by, for example, consumption or administration of that product. The use by date is set such as to be sufficiently short that, under normal storage conditions, there is no possibility of any harmful degradation of the packaged product prior to use. However, by setting a short storage period, perfectly good product, often expensive product, is invariably wasted.

It is thus an aim of the present invention to provide an analysable package which allows for non-invasive analysis of the packaged product.

As will be appreciated, non-invasive analysis, as provided by the analysable package of the present invention, allows for the condition of packaged product to be determined, and thereby both enables the identification of bad product and prevents the disposal of good product. This determination can be based on the identification of one or more characteristic by-products resulting from the degradation of the packaged product or the ingress of foreign components, such as the air, into the package. This latter determination is particularly applicable to pharmaceuticals which increasingly have to be maintained in a controlled atmosphere. For foodstuffs, this analysis could be by the distributor prior to distribution, the retailer prior to display, or the customer prior to purchase. Indeed, in the present climate, where there have been a number of health scares, particularly over the condition of meat products, the possibility of analysis by a customer is desirable in providing confidence in the product.

It is also envisaged that the present invention could be utilised for experimental purposes, allowing for the non-invasive lifetime analysis of packaged product. Accordingly, the present invention provides an analysable package, comprising: a sealable container for containing a degradable product; and first and second electrode members each including a conductive electrode, which electrodes are spaced and define a plasma-generation region in the container in which a plasma is in use generated on connecting a power supply to the electrodes.

Preferably, the electrode members are configured for wireless communication with the power supply.

In one embodiment the electrode members are configured for capacitive coupling with the power supply.

In another embodiment the electrode members are configured for ac coupling with the power supply.

In one embodiment the electrodes are disposed to an inner surface of the container.

Preferably, the electrode members are disposed to an inner surface of the container and enclosed thereby.

In another embodiment the electrode members are sections of the container, the opposed edges of which define the electrodes.

Preferably, the container comprises first and second conductive sections which define the electrode members and a third non-conductive section which defines the plasma- generation region.

In one embodiment the container is a flexible container.

In another embodiment the container is a rigid container. n J

Preferably, the container is formed of a plastics material.

More preferably, the plastics material is polyester.

Preferably, the lateral dimension of the plasma-generation region is from about 10 μm to about 5 mm.

More preferably, the lateral dimension of the plasma-generation region is from about 0.5 to about 2 mm.

Preferably, the electrode members each include an electrode pad for providing a means of electrical coupling to the power supply.

More preferably, the electrode pads each have a surface area of at least about 1 cm².

Yet more preferably, the electrode pads each have a surface area of at least about 10 cm

In one embodiment the electrodes comprise opposed elongate elements.

In another embodiment the electrodes comprise opposed triangular pointed elements.

In a further embodiment the electrodes comprise opposed arcuate elements.

In a yet further embodiment the electrodes comprise substantially circular elements.

In a preferred embodiment the electrode members each include a plurality of electrodes.

In one embodiment the package further comprises a film which at least partially overlies the electrode members, the film including an aperture in registration with the plasma- generation region to allow gas flow into and out thereof. In another embodiment the package further comprises a gas-permeable film which overlies the electrode members.

The present invention also provides an analysis system, comprising: a power supply; first and second power electrodes for supplying power to an analysable package which includes electrode members for generating a plasma in the container when connected to the power supply; a controller for controlling the power supply; and an optical detector for detecting the optical emission of a generated plasma.

In one embodiment the controller is configured to drive the power supply in a pulsed mode.

More preferably, the pulse widths are in the range of from about 10 ns to about 10 ms.

Yet more preferably, the pulse widths are in the range of from about 50 to about 400 μs.

In another embodiment the power supply is an ac power supply.

Preferably, the frequency is in the range of from about 10 Hz to about 1 MHz.

More preferably, the frequency is in the range of from about 350 Hz to about 1.8 kHz.

Preferably, the power electrodes are configured for wireless communication with the electrode members of the analysable package.

In one embodiment the power electrodes are configured for capacitive coupling with the electrode members of the analysable package.

In another embodiment the power electrodes are configured for ac coupling with the electrode members of the analysable package.

The present invention further provides a method of analysing a packaged product, comprising the steps of: providing an analysable package comprising a sealed container containing a degradable product, and first and second electrode members each including a conductive electrode, which electrodes are spaced and define a plasma-generation region in the container in which a plasma is in use generated on connecting a power supply to the electrodes; supplying power to the electrode members of the analysable package to generate a plasma in the container; and detecting the optical emission of the plasma to enable determination as to the condition of the packaged product.

Preferred embodiments of the present invention will now be described hereinbelow by way of example only with reference to the accompanying drawings, in which:

Figure 1 schematically illustrates an analysable package in accordance with a first embodiment of the present invention;

Figure 2 illustrates a plan view of the electrode assembly of the analysable package of Figure 1 ;

Figure 3 illustrates a vertical sectional view (along section I-I in Figure 2) through the electrode assembly of the analysable package of Figure 1 ;

Figure 4 illustrates a plan view of a first-modified electrode assembly for the analysable package of Figure 1;

Figure 5 illustrates a plan view of a second-modified electrode assembly for the analysable package of Figure 1;

Figure 6 illustrates a plan view of a third-modified electrode assembly for the analysable package of Figure 1;

Figure 7 illustrates a vertical sectional view through the electrode assembly of an analysable package as a first modification of the analysable package of Figure 1 ; Figure 8 illustrates a vertical sectional view through the electrode assembly of an analysable package as a second modification of the analysable package of Figure 1;

Figure 9 schematically illustrates an analysable package in accordance with a second embodiment of the present invention;

Figure 10 schematically illustrates an analysis system in accordance with an embodiment of the present invention;

Figure 11 illustrates the circuitry of the analysis system of Figure 10;

Figure 12 schematically illustrates the interface of the analysable package of Figure 1 and the analysis system of Figure 10; and

Figure 13 illustrates the detected emission spectra obtained from the analysable package of Figure 1 when containing air and carbon dioxide.

Figures 1 to 8 illustrate an analysable package 1 in accordance with a first embodiment of the present invention.

The package 1 comprises a sealed container 3 containing a degradable product 5, in this embodiment a foodstuff, and an electrode assembly 7 disposed within the container 3 for generating a plasma.

In this embodiment the container 3 is a flexible container, preferably a bonded plastics film which is vacuum packed. In alternative embodiments the container 3 could take any form, for example, a rigid container, such as a bottle, and be formed of materials other than plastics, for example, glass.

Referring to Figures 2 and 3, the electrode assembly 7 comprises first and second conductive electrode members 9, 1 1 , in this embodiment metal films disposed on the inner surface of the container 3, which are spaced such as to define a plasma- generation region 13 therebetween. The electrode members 9, 11 each comprise at least one electrode 9a, 11a, which electrodes 9a, 11a are disposed in opposed relationship and define the plasma-generation region 13 therebetween, and an electrode pad 9b, l ib for providing a means of electrical coupling, in this embodiment capacitive coupling, to an external power supply for generating the plasma.

In this embodiment, as illustrated in Figure 2, the electrodes 9a, 11a comprise opposed elongate elements. The electrodes 9a, 11a can, however, have any configuration which allows a plasma to be generated therebetween. Other suitable electrode configurations are illustrated in Figures 4 to 6. In one modification, as illustrated in Figure 4, the electrodes 9a, 11 a comprise opposed triangular pointed elements. In another modification, as illustrated in Figure 5, the electrodes 9a, 11a comprise opposed curved elements. In a further modification, as illustrated in Figure 6, the electrodes 9a, 11a comprise a plurality of opposed elongate elements.

Figure 7 illustrates a package 1 as one modification of the above-described first package 1. This modified package 1 includes a film 15, which includes an aperture 17 and overlies the electrode assembly 7 so as to cover the electrode members 9, 11 with the aperture 17 in registration with the plasma-generation region 13 and allow gas flow into and out thereof, and thereby both mechanically protect the electrode members 9, 11 and minimise contact between the electrode members 9, 11 and the product.

Figure 8 illustrates a package 1 as another modification of the above-described first package 1. This modified package 1 includes a gas-permeable film 19 which overlies the electrode assembly 7 so as completely to cover the electrode members 9, 11 and allow gas flow into and out of the plasma-generation region 13, and thereby both mechanically protect the electrode members 9, 11 and prevent contact between the electrode members 9, 11 and the product.

Figure 9 illustrates an analysable package 21 in accordance with a second embodiment of the present invention.

The package 21 comprises a sealed container 23 containing a degradable product 25, in this embodiment a foodstuff. The container 23 comprises first and second conductive sections 27, 29 connected by a narrow non-conductive strip 31 which defines a plasma- generation region 33 between the opposed edges of the conductive sections 27, 29, which opposed edges define electrodes 27a, 29a. The main body of each of the conductive sections 27, 29 defines an electrode pad 27b, 29b. In this embodiment the container 23 is a flexible container, with the conductive sections 27, 29 being metal films or metallised films. Similarly to the above-described first embodiment, the container 23 could take any form, for example, a rigid container, such as a bottle.

Figure 10 illustrates an analysis system 35 in accordance with an embodiment of the present invention.

The analysis system comprises first and second power electrodes 37, 39, in this embodiment metal plates, through which power is supplied to the electrode members 9, 11; 27, 29 of an analysable package 1, 21, a power supply 41 for supplying power to the power electrodes 37, 39, an optical detector 43 for detecting the optical emission from a generated plasma, and a controller 45 for controlling the operation of the power supply 41 and the detector 43.

As illustrated in Figure 11, the power supply 41 comprises a generator unit 47 for generating a pulsed waveform, a pulse-shaping unit 49 for shaping the pulses of the pulsed waveform, a power control unit 51 for controlling the power of the pulsed waveform, and a high-tension (HT) unit 53 for generating a high-tension voltage from the pulsed waveform to drive power through the electrode members 9, 11 ; 27, 29 of an analysable package 1, 21 and generate a plasma in the plasma-generation region 3, 33 thereof. In this embodiment the frequency is controllable in the range of from about 350 Hz to about 1.8 kHz, with pulse widths in the range of from about 50 to about 400 μs.

The generator unit 47 includes a control 55 for adjusting the frequency of the generated waveform. The power control unit 51 includes a control 57 for controlling the intensity of the generated plasma. In this embodiment the power level is controllable up to about 150 mW.

In this embodiment the optical detector 43 comprises a spectrometer for receiving the optical emission from a generated plasma. In alternative embodiments the optical detector 43 comprises a photosensor and an associated filter. In preferred embodiments the photosensor comprises a photomultiplier tube or a photodiode, in particular an avalanche photodiode.

The present invention will now be described with reference to the following non- limiting Example.

Example

In this Example, the analysable package 1 of the above-described first embodiment was filled in turn with air and carbon dioxide, and for each system a plasma was generated therein using the above-described analysis system 35. The resulting optical spectra as detected by the optical detector 43 are illustrated in Figure 13.

Finally, it will be understood that the present invention has been described in its preferred embodiments and can be modified in many different ways without departing from the scope of the invention as defined by the appended claims.

In one alternative embodiment the electrode members 9, 11 ; 25, 27 could be configured to be directly electrically coupled to an external power source. In one preferred embodiment, direct electrical coupling could be achieved by providing apertures in the wall of the container 3 adjacent the electrode members 9, 11.

In another alternative embodiment the electrode members 9, 11 could be configured for coupling to an external ac power source. In this embodiment the electrode pads 9b, 1 lb each comprise at least one loop, for example, a single loop or a spiral, which has a diameter at least as great as the distance therebetween and acts as an antenna. Typically, such electrode pads 9b, 1 lb would have a spacing of about 100 μm. In this embodiment the electrodes 9a, 11a are circular and have a diameter at least as great as the spacing to the respective electrode pads 9b, 1 lb.

Claims

1. An analysable package, comprising: a sealable container (3; 23) for containing a degradable product (5; 25); and first and second electrode members (9, 11; 27, 29) each including a conductive electrode (9a, 13 a; 27a, 29a), which electrodes (9a, 11a; 27a, 29a) are spaced and define a plasma-generation region (13; 29) in the container (3; 23) in which a plasma is in use generated on connecting a power supply (41) to the electrodes (9a, 11a; 23a, 23b).

2. The package of claim 1, wherein the electrode members (9, 11; 27, 29) are configured for wireless cornmunication with the power supply (41).

3. The package of claim 2, wherein the electrode members (9, 11; 27, 29) are configured for capaciti ve coupling with the power supply (41).

4. The package of claim 2, wherein the electrode members (9, 11) are configured for ac coupling with the power supply (41).

5. The package of any of claims 1 to 4, wherein the electrodes (9a, 11a) are disposed to an inner surface of the container (3).

6. The package of claim 5, wherein the electrode members (9, 11) are disposed to an inner surface of the container (3) and enclosed thereby.

The package of any of claims 1 to 3, wherein the electrode members (27, 29) are sections of the container (23), the opposed edges of which define the electrodes (27a, 29a).

The package of claim 7, wherein the container (23) comprises first and second conductive sections which define the electrode members (27, 29) and a third non-conductive section (31) which defines the plasma-generation region (33).

. The package of any of claims 1 to 8, wherein the container (3; 23) is a flexible container.

10. The package of any of claims 1 to 8, wherein the container (3; 23) is a rigid container.

11. The package of any of claims 1 to 10, wherein the container (3 ; 23) is formed of a plastics material.

12. The package of claim 11 , wherein the plastics material is polyester.

13. The package of any of claims 1 to 12, wherein the lateral dimension of the plasma-generation region (13; 33) is from about 10 μm to about 5 mm.

14. The package of claim 13, wherein the lateral dimension of the plasma-generation region (13; 33) is from about 0.5 to about 2 mm.

15. The package of any of claims 1 to 14, wherein the electrode members (9, 11) each include an electrode pad (9b, l ib; 27b, 29b) for providing a means of electrical coupling to the power supply (41).

16. The package of claim 15, wherein the electrode pads (9b, l ib; 27b, 29b) each have a surface area of at least about 1 cm .

17. The package of claim 16, wherein the electrode pads (9b, l ib; 27b, 29b) each have a surface area of at least about 10cm .

18. The package of any of claims 1 to 17, wherein the electrodes (9a, 1 la) comprise opposed elongate elements.

19. The package of any of claims 1 to 17, wherein the electrodes (9a, 11a) comprise opposed triangular pointed elements.

20. The package of any of claims 1 to 17, wherein the electrodes (9a, 11a) comprise opposed arcuate elements.

21. The package of any of claims 1 to 17, wherein the electrodes (9a, 11a) comprise substantially circular elements.

22. The package of any of claims 1 to 21, wherein the electrode members (9, 11; 27, 29) each include a plurality of electrodes (9a, 11a; 27a, 29a).

23. The package of any of claims 1 to 22, further comprising a film (15) which at least partially overlies the electrode members (9, 11; 27, 29), the film (15) including an aperture (17) in registration with the plasma-generation region (13; 33) to allow gas flow into and out thereof.

24. The package of any of claims 1 to 22, further comprising a gas-permeable film (19) which overlies the electrode members (9, 11 ; 27, 29).

25. An analysis system, comprising: a power supply (41); first and second power electrodes (37, 39) for supplying power to an analysable package (1; 21) which includes electrode members (9, 11; 27, 29) for generating a plasma in the container (3; 23) when connected to the power supply (41); a controller (45) for controlling the power supply (41 ); and an optical detector (43) for detecting the optical emission of a generated plasma.

26. The analysis system of claim 25, wherein the controller (45) is configured to drive the power supply (41) in a pulsed mode.

27. The analysis system of claim 26, wherein the pulse widths are in the range of from about 10 ns to about 10 ms.

28. The analysis system of claim 27, wherein the pulse widths are in the range of from about 50 to about 400 μs.

29. The analysis system of claim 25, wherein the power supply (41) is an ac power supply.

30. The analysis system of any of claims 26 or 29, wherein the frequency is in the range of from about 10 Hz to about 1 MHz.

31. The analysis system of claim 30, wherein the frequency is in the range of from about 350 Hz to about 1.8 kHz.

32. The analysis system of any of claims 25 to 31 , wherein the power electrodes (37, 39) are configured for wireless communication with the electrode members (9,

11 ; 27, 29) of the analysable package.

33. The analysis system of claim 32, wherein the power electrodes (37, 39) are configured for capacitive coupling with the electrode members (9, 11; 27, 29) of the analysable package.

34. The analysis system of claim 32, wherein the power electrodes (37, 39) are configured for ac coupling with the electrode members (9, 11) of the analysable package.

35. A method of analysing a packaged product, comprising the steps of: providing an analysable package (1, 21) comprising a sealed container (3; 23) containing a degradable product (5; 25), and first and second electrode members (9, 1 1 ; 27, 29) each including a conductive electrode (9a, 11a; 27a, 29a), which electrodes (9a, 11a; 27a, 29a) are spaced and define a plasma- generation region (13; 33) in the container (3; 23) in which a plasma is in use generated on connecting a power supply (41) to the electrodes (9a, 11a; 23a, 23b); supplying power to the electrode members (9, 11; 27, 29) of the analysable package (1 ; 21) to generate a plasma in the container (3; 23); and detecting the optical emission of the plasma to enable determination as to the condition of the packaged product (5; 25).

36. An analysable package substantially as hereinbefore described with reference to Figures 1 to 8 and/or Figure 9, optionally in conjunction with Figures 10 to 14, of the accompanying drawings.

37. An analysis system substantially as hereinbefore described with reference to Figures 10 to 14, optionally in conjunction with Figures 1 to 8 and/or Figure 9, of the accompanying drawings.

38. A method of analysing a packaged product substantially as hereinbefore described with reference to Figures 10 to 14, optionally in conjunction with Figures 1 to 8 and/or Figure 9, of the accompanying drawings.