FR2751614A1 - ANTI-THEFT PACKAGE AND METHODS OF MAKING SUCH A PACKAGE - Google Patents

Abstract

Anti-theft packaging of the type incorporating an electromagnetic marker (2, 10, 11, 12, 20) formed by a metal wire capable of interacting with a detection device, characterized in that said marker (2, 10, 11, 12, 20) is incorporated into the bulk of the packaging made of expanded polystyrene.

Description

ANTI-THEFT PACKAGING AND METHODS OF

MANUFACTURE OF SUCH A PACKAGING.

  The present invention relates to an anti-theft packaging of the type incorporating an electromagnetic marker. This marker is conventionally formed by a metallic wire capable of interacting with a

detection device.

  Such markers are known in the state of the art, and are for example described in French patents FR763681 or more recently in improvement patents FR2623003 or FR2619929. They are generally affixed to the articles to be protected in the form of labels, as described in patent FR2666433. These labels have the disadvantage of being easily neutralized by tearing. The problem is particularly important when the label is intended to be affixed on a plastic support allowing a detachment

  easy, or on an article protection film.

  Also known from European patent EP704828 is a package having a cavity in which is housed a magnetostrictive marker. However, such packaging does not have a satisfactory level of security, since the position of the marker is easily identified, and the marker can therefore easily

be neutralized or removed.

  The object of the invention is to provide secure packaging having a higher degree of security, and being moreover compatible with the packaging of food products such as meat, vegetables, or any other product.

  usually packaged in such packages.

  To this end, the invention relates to an expanded polystyrene packaging in which the marker is incorporated. The marker is thus invisible from the outside. Preferably, the marker is formed by a section with a length of between 30 and 100 millimeters, and with a section of the order of 25 microns to

2 millimeters.

  According to an advantageous variant, the marker is formed by a metal wire encapsulated in a sheath

  of protection allowing passage to the microwave oven.

  The packaging can thus be introduced into a microwave oven without the heating of the marker by the microwave frequencies causing

packaging degradation.

  The invention also relates to a method of manufacturing an anti-theft packaging characterized in that an electromagnetic marker is positioned in a mold prior to the injection of the material.

constituting the packaging.

  According to a preferred embodiment, a marker is positioned in the mold using a

  support and the said support is removed during molding.

  Advantageously, the marker is positioned inside the mold using a hollow needle allowing the distal end of the marker to protrude, and in that said hollow needle is removed when the end of the marker is retained by the material in

molding courses.

  According to another embodiment, inserts are prepared formed by markers coated with a material constituting the packaging and in that such an insert is introduced into the mold for manufacturing

packaging.

  Advantageously, the inserts consist of a marker coated with polystyrene beads, such a marker being introduced into the mold during the step

packaging manufacturing.

  The invention will be better understood on reading

  of the following description, referring to

  appended figures relating to nonlimiting exemplary embodiments o: - Figure 1 shows a perspective view of an anti-theft packaging according to the invention; - Figures 2 to 7 show schematic views of the different stages of manufacturing a

such packaging.

  FIG. 1 represents a perspective view of an anti-theft packaging according to the invention. It consists of a tray (1) of expanded polystyrene whose shape and external characteristics are known in the state of the art. Such trays are usually used for the packaging of products such as meat, vegetables, or even all products usually packaged in such packages. They are usually closed with a transparent film. Such trays are described for example in patent FR2648792. This patent relates to a polystyrene-based food tray intended for vacuum packaging of fresh product by draping a flexible plastic film comprising an opening tab and its manufacturing process. Another patent of the prior art, patent FR2640584 describes another form of tray for packaging a food product. This

  container has the general shape of a flat-bottomed bowl.

  It is intended to receive the product and to be

  then covered with a thin plastic film.

  The flat bottom is lined with a series of fine ribs arranged to support the product at a certain distance above the bottom, so that the product does not come into contact with the areas of this bottom which are located between the ribs. Air trapped under the thin film can circulate freely

  in the space between the product and the bottom.

  The packaging differs from these trays of the prior art in that one of the walls incorporates a marker (2) formed by a metal wire. As an indication, it is a magnetic wire, for example made of a cobalt alloy, or a metal having a specific magnetic hysteresis characteristic allowing easy characterization with a system of

  detection including an induction loop.

  This wire has a length of the order of 70 millimeters and a section of 25 microns. It is completely embedded in the material forming the wall of the package. The packaging has no opening for introducing this marker (2), so as to prevent

  visual identification of its positioning.

Figure 2 shows an example

  of equipment for the manufacture of such packaging.

  The packaging is produced in a known manner using a mold (17) into which are injected the polystyrene beads, expanded in the usual way by steam. One of the walls (18) of the mold (17) has a

  orifice allowing the passage of a support for markers.

  This support consists of two concentric cylindrical sections (14, 15). The inner section (15) receives markers (10, 11, 12) thanks to a system

feed.

  Figures 2 to 7 illustrate the different

  steps for manufacturing a package according to the invention.

  The marker is prepared in the form of a coil cut into sections (10, 11, 12) with a length Lm of

  70 millimeters in the example described.

  The marker holder is formed by two concentric hollow needles (14, 15). The outer needle (14) has a length Lae of a length equal to Lm + P, where P denotes the distance between the end (16) of the marker (10) and the wall (18) of the mold, in the final packaging. P denotes the depth of the marker. The inner needle (15) has a length Lai equal to several sections of markers (10 to 12), ie in the example described 210 millimeters. The section of the inner needle (15) is determined so as to allow advancement of the markers without friction. FIG. 3 represents a front view of the assembly formed by the two concentric needles and of the marker (10). The section of the markers (10, 11, 12) is less than the section of the inner needle (15), but sufficient to prevent the overlapping of two markers inside the medular canal of

the inner needle (15).

  At the start of the manufacturing cycle for a new package, the balls are introduced into the mold (17). The inner needle (15) and the outer needle (14) are both in the advanced position, and penetrates inside the mold with a length of about mm. The front end (19) of the most advanced marker (10) protrudes from the needles by a length of about 5 mm. The inner needle (14) is then withdrawn, until it occupies a position in which the front end is located in the plane of the front end of the second marker (11), as shown in

figure 4.

  The marker (10) rests in the medular channel of the outer needle (14) and is blocked at the rear by the inner needle (15). Figure 4 'shows a front view of the two consecutive markers (10, 11) at the time of cooking the polystyrene beads. The marker (10) is blocked at the front end (19) by the polystyrene balls which

begin their expansion.

  Then remove, as shown in the figure, the outer needle (14), then the inner needle (15) which served as a stop. The expansion of the balls continues, which closes the channel left by the withdrawal of the needles (14, 15).

  The packaging is then ready to be removed from the mold.

  The next step shown in FIG. 6 consists in advancing the needles (14,) and the markers with a length of 70 mm using a set of jaws (26). We cut a section

  (20) additional, using a cutting tool (25).

  To return to the beginning of the cycle, the introduction of the needles (14, 15) into the mold is continued and the sections (11, 12, 20) are advanced using the jaw (26) until the new front section (11) extends 5 millimeters from the front end of

the inner hollow needle (15).

  The equipment then returns to the position of

  start of cycle shown in figure 2.

  The invention is described in the foregoing by way of nonlimiting example. It is understood that the skilled person will be able to produce various variants without departing from the scope of the invention.

Claims (4)

  1 - Anti-theft packaging of the type incorporating an electromagnetic marker (2, 10, 11, 12, 20) formed by a metallic wire capable of interacting with a detection device, characterized in that said marker (2, 11, 12, 20 ) is incorporated into the mass of   the packaging made of expanded polystyrene.   2 - Anti-theft packaging according to claim 1, characterized in that said marker (2, 10, 11, 12,) is formed by a section with a length between 30 and 100 millimeters, and a section of the order from 25 microns to 2 millimeters.   3 - Anti-theft packaging according to claim 1 or 2 characterized in that the marker (2, 10, 11, 12,) is formed by a metal wire encapsulated in a   protective sheath allowing passage to the micro-   wave. 4 - Method for manufacturing an anti-theft packaging characterized in that an electromagnetic marker (2, 10, 11, 12, 20) is positioned in a mold prior to the injection of the material constituting the packaging.   - Method of manufacturing an anti-theft packaging according to claim 4 characterized in that a marker (2, 10, 11, 12, 20) is positioned in the mold using a support and that one withdraw said support during molding.   6 - A method of manufacturing an anti-theft packaging according to claim 4 or 5 characterized in that one positions the marker (2, 10, 11, 12, 20) inside the mold using a or several hollow needles allowing the distal end of the marker to protrude (2, 10, 11, 12, 20), and in that said hollow needles are removed when the end of the marker is retained by the material being molded . 7 - Method of manufacturing a package   anti-theft device according to any one of claims 4 to 6   characterized in that polystyrene beads, expanded by steam injection, are introduced into the mold. 8 - Method for manufacturing an anti-theft packaging characterized in that inserts are prepared formed by markers (2, 10, 11, 12, 20) coated with a constituent material of the packaging and in that the such an insert is introduced into the packaging manufacturing mold. 9 - A method of manufacturing an anti-theft packaging according to claim 8 characterized in that the inserts consist of a marker (2, 10, 11, 12, 20) coated with polystyrene beads, such a marker (10, 11, 12, 20) being introduced into the mold for   the packaging manufacturing stage.   - Equipment for the manufacture of an anti-theft packaging formed by a mold intended to receive a hot-melt material or an expandable material, characterized in that it comprises a support movable between a position in which it ensures the positioning of a marker (2 , 10, 11, 12, 20) inside the mold   and a position in which it is retracted.