Authenticatable part, formed by plastic injection, and associated authentication process

Abstract

The invention relates to a part formed by injecting a plastic component into a volume delimited by a surface. Such a part comprises a plurality of distinguishable elements obtained by the presence of a significant quantity of impurities in the plastic component during injection, the distinguishable elements being identifiable on a portion of the surface of the part, the portion being called the identification zone, the part also comprising at least one mark in the vicinity of or inside the identification zone. Figure for abstract: figure 1

Description

Title of the invention: Authenticatable part, formed by plastic injection, and associated authentication method TECHNICAL FIELD OF THE INVENTION

[0001] The field of the invention is that of manufactured parts.

[0002] More specifically, the invention relates to an authenticatable part, formed by plastic injection, and associated authentication method.

[0003] The invention finds applications in particular in the traceability of plastic parts, in particular containers associated with their cap, in particular in the context of monitoring their recycling. STATE OF THE ART

[0004] Techniques for authenticating plastic parts are known from the prior art, in particular based on laser or microscopic marking techniques in order to record information such as a bar code, a serial number or a logo.

[0005] There are also authentication techniques based on the addition of a radio frequency identification (RFID) chip or a security element such as a hologram, a watermark, security ink, or even a QR code (Quick Response Code).

[0006] However, none of these techniques can simultaneously meet all the required needs, namely to propose a technique for authenticating a part whose manufacture is easy to implement in a low-cost industrial process, as is the case, for example, with the manufacture of a bottle stopper whose unit price is much lower than one euro cent. Statement of the invention

[0007] The present invention aims to remedy all or part of the drawbacks of the state of the art cited above.

[0008] To this end, the invention relates to a part formed by injection of a plastic component into a volume delimited by a surface.

[0009] Such a part corresponds to any type of part manufactured by plastic injection, the authentication of which is necessary, for example in the context of traceability of the part between manufacturing, the consumer, or even the recycling of the part. Authentication of the part can also be carried out to verify the correct routing of the part during a process or in any other context requiring traceability.

[0010] According to the invention, the formed part comprises a plurality of distinguishable elements obtained by the presence of a significant quantity of impurities in the plastic component during injection, the distinguishable elements being identifiable on a part of the surface of the part, the part being called the identification zone, the part also comprising at least one mark near or inside the identification zone.

[0011] The presence of impurities here results in distinguishable elements at the part level, which are generally considered as imperfections in the context of manufacturing a part by injection. Such distinguishable elements are visible on the outer surface of the part, and correspond for example to marbling, speckles, dots, lines or dashes. It should be emphasized that the shape of these distinguishable elements can be arbitrary, depending in particular on the way in which the impurities are positioned in the injection mold relative to the plastic component.

[0012] The distinguishable elements can thus be mapped in the identification zone of the part and allow the identification of the part.

[0013] Since the positioning of the impurities in the injection mold used to form the part is done randomly, the mapping of the distinguishable elements in the identification zone can be considered unique. The probability of obtaining two parts having the same mapping can in fact be made sufficiently low by dosing the quantity of impurities in the plastic component.

[0014] It should be emphasized that the mapping is advantageously oriented thanks to the presence of the marker(s) of which at least the shape or relative position is known. The relative position is understood in particular between a marker and the identification zone or between each marker.

[0015] Furthermore, the relief of the mark may correspond to an element of the manufactured part, such as for example a skirt of a cap, or to an element formed on the surface, for example included in the injection mold or formed by engraving after molding.

[0016] In particular embodiments of the invention, the impurities are formed in the same material as the plastic component but with a distinct color tint.

[0017] Thus, the manufacturing process can maintain another manufacturing rate, without significant slowdown, which could be the case when the impurities are formed in a separate material, such as sand, quartz, etc.

[0018] Furthermore, since the impurities have the same density as the plastic component, better dispersion of the impurities within the mixture with the plastic component can be achieved, thus avoiding agglomeration of imperfections in a portion of the identification area.

[0019] In particular embodiments of the invention, the identification zone has a predetermined shape.

[0020] The identification zone has a two-dimensional, or even three-dimensional, shape, making it possible to authenticate the formed part by carrying out a mapping of the identification zone, the shape of which is advantageously known.

[0021] It should be noted that authentication can be done via a simple photograph, or in cases of complex form, via several photographs of the part, or even a scan or a video.

[0022] In particular embodiments of the invention, the identification zone is planar.

[0023] This advantageous embodiment makes it possible to easily authenticate the part from a single photo of the identification zone.

[0024] In particular embodiments of the invention, at least one marker has the shape of a truncated circle.

[0025] Such a marker may, for example, correspond to a characteristic element of the part to be authenticated.

[0026] In particular embodiments of the invention, the quantity of impurities is between 1 and 10% of the volume of the plastic component.

[0027] Preferably, the quantity of impurities is between 2 and 4% of the volume of the plastic component.

[0028] In particular embodiments of the invention, at least one relative dimension between two elements of the reference mark(s) is known.

[0029] Thus, it is possible to provide a scale to the identification zone.

[0030] In particular embodiments of the invention, the part forms a stopper for a container such as a bottle.

[0031] In particular embodiments of the invention, the plastic component is high density polyethylene (HDPE).

[0032] The invention also relates to a method of manufacturing a part according to any one of the preceding embodiments, during which during injection a significant quantity of impurities is mixed with the plastic component.

[0033] It should be emphasized that the mixing can be carried out before or during the injection.

[0034] In particular embodiments, the impurities are injected only for at least a predetermined period.

[0035] Thus, it is possible to restrict the formation of distinguishable elements in at least one part of the part. This is notably achievable by the use of two separate injection nozzles.

[0036] A variation in the flow rate of each nozzle can also be implemented during of the manufacturing process in order to densify the formation of distinguishable elements in certain areas.

[0037] The variation may also create additional randomness in the formation of distinguishable elements in the identification zone.

[0038] In particular embodiments, the manufacturing method also comprises a step of marking at least one mark on the surface of the part.

[0039] The marking can be carried out for example by an engraving technique, by a printing technique, or by any other technique known to those skilled in the art.

[0040] Finally, the invention also relates to a method for authenticating a part according to any one of the preceding embodiments, comprising steps of: • acquisition, by a camera, of at least one image of the identification zone of the part; • detection of the marker(s) in said at least one image of the identification zone of the part; • determination of an orientation of the identification zone relative to the camera and of a characteristic dimension of the marker(s) in the image; • transformation of the image of the identification zone according to the orientation determined previously, the transformation including a rotation and / or any other geometric deformation of known mathematical definition; • mapping of visible imperfections in the image; and • comparison of the obtained mapping with a database of cars existing topography.

[0041] A geometric deformation of known mathematical definition corresponds in particular to a transfer matrix from one geometric reference frame to another geometric reference frame. Such a deformation may include a rotation, a homothety, a translation, etc. BRIEF DESCRIPTION OF THE FIGURES

[0042] Other advantages, aims and particular characteristics of the present invention will emerge from the following non-limiting description of at least one particular embodiment of the devices and methods which are the subject of the present invention, with reference to the appended drawings, in which: • [Fig.l] is a perspective view of an exemplary embodiment of a part formed according to the invention, in this case a stopper intended to seal a bottle; • [Fig.2] is a perspective view of another exemplary embodiment of a part formed according to the invention, in this case a meal tray; • [Fig.3] is a perspective view of another exemplary embodiment of a part formed according to the invention, in this case a telephone shell; • [Fig.4] is a block diagram of an example of implementation of a method of manufacturing a part formed according to the invention; • [Fig.5] is a block diagram of an example of implementation of a method for authenticating a part formed according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0043] The present description is given without limitation, each characteristic of an embodiment being able to be combined with any other characteristic of any other embodiment in an advantageous manner.

[0044] It should be noted, from now on, that the figures are not to scale. Example of a particular embodiment

[0045] [Fig. 1] is a perspective view of an example of a part 100 formed by plastic injection. In the present non-limiting example of the invention, the part 100 is a plastic cap obtained by injection of a plastic component, namely high-density polyethylene (HDPE). The cap 100 comprises a generally flat cover 105 and a skirt 106 extending from the cover 105. The cap 100 is configured to seal, in a sealed manner, the neck of a bottle 108 in order to be able to transport a liquid, for example mineral water or milk, contained in the bottle 108.

[0046] For the sake of traceability, the cap 100 comprises distinguishable elements 109 visible in an identification zone 110, here presented by the top of the cover 105. By "top of the cover" is meant the outer face opposite the inner face which is surrounded by the skirt 106 and which is intended to come into contact with the neck of the bottle.

[0047] The distinguishable elements 109 are obtained by adding impurities to the plastic component and correspond in the present non-limiting example of the invention to marbling, lines, dots, speckles or dashes. The impurities are here formed in HDPE but having a different shade from the HDPE used as the main component. For example, the main component may be blue or green, and the impurities white. It should be emphasized that closer shades can be used without harming the authentication result of the part 100. The difference in shade between the main component and the secondary component forming the impurities is chosen according to the sensitivity of the digital image sensors as well as that of the image processing algorithms.

[0048] The cap 100 advantageously comprises at least one marker 120 making it possible to determining the orientation of the identification zone 110 relative to a camera acquiring an image of the cap 100.

[0049] In the present non-limiting example of the invention, the reference 120 corresponds to a hollow formed on the surface of the cover 105, the circumference of which has a predetermined shape whose orientation in the plane can be recognized. The circumference is illustrated here in the form of a truncated circle but it can be a right-angled isosceles triangle or any other shape.

[0050] The mark 120 is here formed in hollow relief but it can also be formed in relief projecting relative to the surface of the cover 105, or by a color marking on the cover 105.

[0051] It should be emphasized that the invention can be applied to any type of manufactured part. For example, it can be a meal tray 200 as illustrated in [Fig.2], comprising a mark 210 having the shape of a right-angled isosceles triangle marked on a handle 220 of the tray 200, and whose identification zone 230 encompassing a portion of the distinguishable elements 240 is formed by the handle 220. It can also be a telephone shell 300 as illustrated in [Fig.3], comprising three marks 310 engraved on the top of the cover 320, the three marks 310 preferably corresponding to the ends of a right-angled isosceles triangle of known dimension. The choice of the mark(s) can be made for reasons of design of the part.

[0052] The part can also be used as a reference when the model of the part is known. For example, in the context of a telephone shell, it is easy to determine an orientation of a telephone shell by taking into account the position of openings formed in the shell opposite elements of the telephone such as a camera, a connector, buttons, etc. This is also the case of the truncated cap as described in French patent application FR2109647.

[0053] The examples presented here are non-limiting and the person skilled in the art seeking to authenticate any plastic part, formed by injection, can adapt without difficulty the present example of an embodiment of the invention, by adding a quantity of impurities in the main component.

[0054] Preferably, the impurities are formed in the same material as the main component or having at least a similar density for reasons of homogeneity of the mixture.

[0055] The materials used for both the main component and the secondary component are any type of plastic material suitable for injection, such as polyethylene (PE), high density polyethylene (HDPE), polyamide, polypropylene, polystyrene, polymethyl methacrylate (PMMA), poly(ethylene terephthalate) (PET), etc.

[0056] The impurities may also correspond to a different grade than the main component. The injected part may, for example, be manufactured with two grades of polyethylene.

[0057] In variations of this particular embodiment of the invention, the impurities may be formed in a different material such as sand, quartz, etc. to form distinguishable features such as inclusions.

[0058] It should be emphasized that to the extent that the impurities are injected with the main component, the detectable elements may extend beyond the identification zone 110.

[0059] [Fig.4] illustrates in the form of a block diagram a method 400 for manufacturing the part 100.

[0060] The manufacturing method 400 comprises a step 420 of forming the part by plastic injection of the plastic component comprising a significant quantity of impurities in the injection mold.

[0061] The plastic injection technique used during this second step 420 is similar to techniques well known to those skilled in the art.

[0062] It should be emphasized that the impurities can be mixed with the plastic component upstream of the injection, during a step 410, or be injected separately directly into the injection mold via two separate nozzles.

[0063] It may also be envisaged to judiciously inject the impurities, for example to concentrate the distinguishable elements in the identification zone. Considering an injection through the center of the part, the main component may for this purpose be injected alone initially and then with the impurities in a second stage. As illustrated in [Fig.2], the distinguishable elements 240 may thus be concentrated on the periphery of the part 200.

[0064] Optionally, the manufacturing method 400 comprises a third step 430 of etching at least one mark on the outer surface of the part 100, near or inside the identification zone 110. This third step 430 is notably implemented when at least one mark is not formed directly during the second injection step, by the presence of a corresponding imprint in the injection mold. The etching of a mark is for example not necessary when the mark corresponds to an element of the part that can be identified without difficulty, such as for example the truncated shape of the cap or when the three-dimensional model of the part is known. In the latter case, the part generally comprises an asymmetry along at least one axis or plane, in order to allow its orientation to be identified without difficulty in an image.

[0065] [Fig.5] illustrates in the form of a block diagram a method 500 for authenticating the part 100.

[0066] The authentication method 500 comprises a first step 510 of acquisition by a camera of at least one image of the identification zone 110 of the part 100.

[0067] During a second step 520 of the method 500, a detection of the marker(s) in at least one previously acquired image is carried out, here of the marker 120 formed in hollow on the outer surface of the cover 105 of the cap 100. This recognition can for example be carried out by any technique well known to those skilled in the art such as for example a detection of landmarks in the image, a detection by deep learning techniques known by the English term “deep learning”, etc.

[0068] Once the marker(s) have been detected in at least one image, or even in each image, a determination of an orientation of the zone 110 relative to the camera is carried out during a third step 530 for each acquired image.

[0069] The determination of the orientation is carried out by calculating the deformation of a representative model of the reference frame(s) superimposed on the reference frame(s). Depending on the case, the representative model may be three-dimensional or two-dimensional (plane). In the example of [Fig.l], the representative model is a plane of the circumference of the cover 105, i.e. a truncated circle.

[0070] A determination of a pose of a model representative of the reference frame(s), or even of the identification zone, in the reference frame of the camera acquiring the acquired image(s) can be carried out for each acquired image. The pose corresponds to the three-dimensional positioning and orientation of the representative model in the reference frame of the camera, so that the representative model is superimposed on the reference frame(s) visible in each acquired image.

[0071] A characteristic dimension of the marker(s) may also be determined during step 530 in order to give a scale to the identification zone.

[0072] It should be emphasized that steps 520 and 530 can in certain cases be carried out concomitantly, in particular when a deep learning type detection is carried out.

[0073] Once the orientation has been determined, a transformation of the image of the identification zone can be carried out during a fourth step 540 of the method 500. The purpose of this transformation is to straighten the image in order to correspond to an image of the identification zone taken from the front.

[0074] It should be emphasized that this rectification can be similar to the processing carried out when reading a QR code where three markers delimiting the code are identified and are used to determine the orientation and scale of the QR code.

[0075] It should be emphasized that the scale used for mapping is relative to an edge of the marker or by the distance between two markers, and generally serves as a reference for authentication. It is therefore not necessary to know a actual dimension of the marker(s) to perform the authentication. Knowledge of a relative dimension or a dimension ratio, for example the position of the truncation relative to the radius in the case of a truncated circle as for part 100 illustrated in [Fig.l], is sufficient to give a relative scale to the mapping.

[0076] A mapping of the visible distinguishable elements 109 is carried out in the transformed image during a fifth step 550 of the authentication method 500. An algorithm for recognizing the distinguishable elements 109 can thus be implemented, for example using gradient methods to detect the variations in hue in the transformed image of the identification zone 110.

[0077] A comparison of the mapping with a mapping database is then carried out in order to authenticate the part 100. It should be emphasized that the distinguishable elements 109 being random in the identification zone 110, each part 100 has a priori a unique identification zone.

[0078] If the mapping of the identification zone 110 is unknown to the database, a record is proposed to the user in order to increase the base for tracing the part 100 later.

[0079] It should be emphasized that in the case of multiple image capture, which is the case with a video or even a scanner, a concatenation of the different images can be carried out in order to produce a more complete map.

[0080] Optionally, processing of the acquired image(s) may be carried out in order to improve the quality of the images in terms of contrast or brightness. Colorimetric filters may also be implemented. Correction of parasitic reflections may also be envisaged.

[0081] In summary, the present invention makes it possible to produce a plastic part 100 which can be easily authenticated. It should be emphasized that the distinguishable elements 109 allowing authentication are structurally incorporated into the part 100, thus avoiding a loss of the authentication element as could be the case with the addition of a QR code or a hologram, and furthermore making the authentication element, corresponding to the identification zone 110, inviolable, unfalsifiable and impossible to copy.

[0082] It may also be envisaged that the distinguishable elements 109 are invisible to the naked eye, but visible under infrared or ultraviolet light by choosing for example a particular type of impurities or suitable shades.

[0083] Authentication can in particular be used in the context of traceability of the part in the context, for example, of recycling the part, routing the part in a logistics process, identification of the part to know associated information (owner, date of manufacture, place of manufacture, verification of non-counterfeiting, etc.).

Claims

Claims

1. Part formed by injecting a plastic component into a volume delimited by a surface, characterized in that it comprises a plurality of distinguishable elements obtained by the presence of a quantity of impurities positioned randomly in the plastic component during injection, the distinguishable elements being identifiable on a part of the surface of the part, the part being called the identification zone, the part also comprising at least one mark near or inside the identification zone.

2. A part according to claim 1, wherein the impurities are formed in the same material as the plastic component but with a distinct color shade and / or grade.

3. A part according to any one of claims 1 to 2, wherein the identification area has a predetermined shape.

4. A part according to any one of claims 1 to 3, in which the identification area is planar.

5. Part according to any one of claims 1 to 4, in which at least one mark has the shape of a truncated circle.

6. A part according to any one of claims 1 to 5, wherein the amount of impurities is between 1 and 10% of the volume of the plastic component.

7. Part according to any one of claims 1 to 6, in which at least one relative dimension between two elements of the one or two reference marks is known.

8. Part according to any one of claims 1 to 7, forming a stopper for a container such as a bottle.

9. A part according to any one of claims 1 to 8, wherein the plastic component is high density polyethylene (HDPE).

10. Method of manufacturing a part by plastic injection, according to any one of claims 1 to 9, characterized in that during the injection a quantity of impurities is mixed with the plastic component.

11. A manufacturing method according to claim 10, wherein the impurities are injected only for at least a predetermined period.

12. Manufacturing method according to any one of claims 10 to 11, also comprising a step of marking at least one mark on the surface of the part.

13. A method of authenticating a part according to any one of claims 1 to 9, comprising steps of: • acquisition, by a camera, of at least one image of the identification zone of the part; • detection of the marker(s) in said at least one image of the identification zone of the part; • determination of an orientation of the identification zone relative to the camera and of a characteristic dimension of the marker(s) in the image; • transformation of the image of the identification zone according to the orientation determined previously, the transformation comprising a rotation and / or a geometric deformation of known mathematical definition; • mapping of visible imperfections in the transformed image; and • comparison of the obtained mapping with an existing mapping database.

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