FR2810733A1 - Method and equipment for testing watertightness of a container, comprises application of electric potential to conductor in contact with contents while container is immersed in conducting medium - Google Patents

Abstract

A container (1) is immersed in a conducting medium (2) which may be liquid or gas and is surrounded by an electrode (20). A battery (19) is connected to the electrode and also to an electrical connection (3) which is in contact with the contents of the container (4). The container is non-conducting and the electrical connection is insulated where it passes through the container. Any leakage current is detected by an ammeter or voltmeter (17). Independent claims are included for a container adapted to the method and for equipment to apply the method to the container.

Description

The invention relates to a method and a device for testing the leaktightness of a packaging, containing a content, and thus packaging arranged to be tested according to said method.

However, it should be noted that such packaging is not necessary for the implementation of the process according to the invention can be used with other types of packaging.

In this regard, although it is more particularly intended for packaging of food products, the invention can be used in many other fields.

Today, in the field of food product packaging, it is necessary to ensure the tightness of packaging used not only to avoid loss of products but also to limit any risk of contamination of the contents of the packaging to the outside environment .

The methods of testing the tightness of a package, after filling and closing, are rare and when they are implemented, they are only interested in the detection of possible loss of content. on the other hand, are not reliable enough to detect micro-leaks risk causing contamination but do not lead to significant weight reductions.

The object of the present invention is to provide a method and a device for testing the leaktightness of a package enclosing a content, as well as a package specially designed for this purpose, which overcomes the aforementioned drawbacks and makes it possible to detect not only massive losses of content but also of micro-leaks.

Another object of the invention is to propose a method and a device for testing the tightness of a package enclosing a content, as well as a package specially designed for this purpose, which make it possible to carry out non-destructive checks.

Another object of the present invention is to propose a method and a device for testing the leaktightness of a package enclosing a content, as well as a package specially designed for this, which can be integrated ultimately into a cycle. of production.

Other objects and advantages of the invention will become apparent during the description which follows which is given for information only and which is not intended to limit it.

The invention relates first of all to a method for testing the tightness of a package, containing a content, method in which - at least partially positioning said package in an electrically conductive medium, - a conductive connection of the currents is provided between the outside of the packaging and its contents, - an electrical flux is created in said medium at least in the event of a leak, via said connection, - establishment and / or variation are detected said flow. The invention also relates to a packaging, in particular for food products, arranged for implementing the process described above, said packaging consisting of a container, capable of being sealed in relation to its content, and means for establishing a conductive connection of electric currents between said content outside through said container.

The invention also relates to a device for testing the tightness of a package, containing a content, in particular intended for the implementation of the method described above, comprising - an electrically conductive medium capable of allowing at least partial positioning of said package. , - means for establishing an electric current conductive connection between the outside of the packaging and its contents, - means for creating an electrical flow in said medium at least in the event of a leak, through the said connection, - means for detecting the appearance and / or variation of said invention will be better understood on reading the following description, accompanied by the attached drawings which form an integral part thereof and among which - FIG. 1 illustrates with a view to section an example embodiment of the test device according to the invention, - Figure 2 illustrates, in front view, an example embodiment of the packaging me to the invention, - Figure 3 is a sectional view along line 111-11I shown in Figure 2 above.

The invention relates first of all to a method for testing the leaktightness of a package containing a content.

As illustrated in FIG. 1, according to the method according to the invention, said packaging 1 is positioned at least partially in an electrically conductive medium 2 and a conductive connection of the electric currents 3 is provided between the exterior of the packaging 1 and its content 4.

An electrical flow is then created in said medium less in the event of a leak. For this, for example, a potential difference and / or an electric current is established between said content 4 the package 1 and said medium 2, by means of said link 3.

Finally, the appearance and / or variation of said flux is detected, by measuring for example, the voltage and / or the intensity of the current and / or changes in the state of the medium, in particular the presence of initiation phenomena.

Thanks to the process according to the invention, it is thus possible to detect not only relatively small leaks but also micro-leaks, corresponding for example to packaging alterations of the order of a micrometer or even of a tenth of a micrometer.

Said content 4 is, for example, liquid, at least part. These are, in particular, food products in sauce and / or in their juice. Said content 4 is thus provided electrically conductive.

Said medium 1 consists, for example, of a liquid solution of water and salt and / or acid. It is provided capable of fully wetting the submerged outer surface 5 of the packaging and could possibly comprise for this purpose different solvents, solutes, surfactants and / or other constituents suitable for the packaging to be tested.

According to another embodiment, said medium 2 consisting of a gaseous environment, capable of allowing electrical flows to flow.

In order to allow a complete test of said outer surface 5 thereof, said packaging 1 will be fully immersed in said medium 2. As illustrated in FIGS. 2 and 3, said packaging 1 consists, for example, of a container 6, capable of being closed in a sealed manner with respect to its content 4, and of means for establishing a conductive connection of the electric currents 3 between said content 4 and the exterior through said container 6.

Although more particularly arranged to facilitate the implementation of the test method described above, such packaging may nevertheless, according to the invention, find other applications.

Said container 6 may as well be flexible as rigid and / or semi-rigid. It consists, in particular, of at least two faces 7, 8 provided opposite and assembled together, directly or indirectly, on at least part of their contour. Said means for establishing a conductive connection 3 are inserted between said faces 7, 8, for example at the level of said part of their outline where they are assembled or in any other place of the packaging. Such a container can be obtained, in particular from a sleeve of material cut transversely into sections, each section being intended to constitute one of the containers 6. The edges of one of the cut ends of each section are then welded together to define the bottom of said containers It is for example at this level that said means are inserted to establish conductive connection 3, before welding. Said container 6 is then filled with its contents and then closed by welding the edges of the other cut end of said container 6.

According to another embodiment, said container is obtained by assembling two sheets of material placed opposite. These are for example welded on a part of their contour to form the bottom 9 and the longitudinal sides of said container 6, provided rectangular. Said means for establishing a conductive connection 3 can be inserted between said faces 6, 7 at this level.

Said container 6 is then filled with its contents and then closed by welding the last edge 11 of said container 6.

According to other embodiments, said means for establishing a conductive connection 3 may also be located at the opening of said container 6. They will then be positioned, for example, after filling.

Said container 6 may also be provided with bellows at its longitudinal edges.

Said means for establishing a conductive connection consist, for example, of conduction means 12, electrically conductive at least on the surface, passing through said container 6 and subject to the latter, the surface of said conduction means being isolated but provided with at least a non-insulated area 13, 14 on either side of said container They are in particular located at the longitudinal ends of said conduction means 12, the outer end 13 being intended to allow an electrical connection and the inner end 14 being intended to be immersed in said content 4.

Said conduction means 12 are insulated, for example, at least at their part passing through said container 6. For this, are coated, in particular, with a layer of insulating material 15.

The faces 7, 8 of the container 6 consist, for example, of a metal sheet sandwiched between two sheets of non-conductive material. Said container is thus electrically insulating, at least between the inside of the packaging and the outside.

Referring again to FIG. 1, it can be seen that the invention also relates to a device for testing the tightness of a package 1 enclosing a content 4, said device comprising - an electrically conductive medium 2 capable of allow at least partial positioning of said package 1, - means for establishing an electric current conductive connection 3 between the exterior of the package 1 and its contents 4, - means 16 for creating an electrical flux in said medium at least in in the event of a leak, through said connection - means 17 for detecting the appearance and / or variation of said flow.

Said medium 2 is provided, for example, inside tank 18. Said means 16 for creating an electrical flow consist, in particular, of a current and / or voltage generator 19 connected, on the one hand, to the external non-insulated zone 13 of said means for establishing a conductive connection 3 and, on the other hand, to a device 20 placed in said medium, in particular an electrode.

They thus allow, for example, the establishment of a potential difference between the content 4 of the packaging and said device 20 and, subsequently, the appearance of an electrical flux in the medium 2, in the event of a leak.

Said means 17 for detecting consist, in particular, of a voltmeter, of an ammeter, provided for measuring the voltage or the current applied, or of any other apparatus corresponding to the characteristic which one wishes to note.

This being the case, it should be noted that the non-isolated zones 3, 14 of the conduction means 12 could possibly consist of several points. In such a case, on the side of the external non-insulated zone 13, connection means provided capable of bringing all of said points into contact with the conductor 21 connecting said means to establish a conductive connection 3 said generator 19, or to isolate part of these may be provided. on its side, said device 20 means for creating a can be isolated, only partially, in said medium 2.

Naturally, other modes of implementation, within the reach of those skilled in the art, could have been envisaged without departing from the scope of the invention.

Claims (10)

<B> CLAIMS </B> 1. Method for testing the packaging seal (1), containing a content (4), method in which - said packaging (1) is positioned at least partially in an electrically conductive medium (2), - a conductive connection is provided electric currents (3) between the outside of the packaging (1) and its contents (4), - an electric flow is created in said medium (2), at least in the event of a leak, by the through said link (3), - one or more characteristics of said current are measured. 2. Packaging, in particular for food products, consisting of a container (6), capable of being sealed in relation to its content and of means for establishing a conductive connection of electric currents between said content (4) and the exterior through said container (6). 3. Packaging according to claim in which said container consists of at least two faces (7, 8) provided opposite and assembled together, directly or indirectly, on at least part of their outline, said means to establish a conductive connection (3) being inserted between said faces (7, 8) at the part of their outline where they are assembled. 4. Packaging according to claim 2, wherein said means for establishing a conductive connection (3) consist of conduction means 2), electrically conductive at least on the surface, passing through said container (6) and subject to the latter, the surface said conduction means 2) being isolated but provided with at least one non-isolated zone (13, 14) from the other of said container (6). 5. Packaging according to claim wherein said conduction means (12) are isolated at least at their part passing through said container (6). 6. Packaging according to claim in which said container is electrically insulating, at least between the interior of the packaging and the exterior. 7. Packaging according to any one of claims 2 to and its content (4) provided electrically conductive. 8. The method of claim 1, wherein said package to be tested consists of a package according to claim 7. 9. Device for testing the tightness of a package containing a content (4), comprising - an electrically conductive medium (2) capable of allowing at least partial positioning of said package (1), - means for establishing a conductive connection electric currents (3) between the outside of the packaging and its contents, - means (16) for causing an electric flow to be created in said medium (2), at least in the event of a leakage, by the through said link (3), - means (17) for detecting the appearance and / or the variation of said flow. 10. Device according to claim 9, comprising said package to be tested (1) itself, provided consisting of a package according to claim 7.