FR2970202A1 - Method for manufacturing three-dimensional, rectangular, self-adhesive radio frequency identification label, utilized for fixing on e.g. labeling surface of bottle, involves solidifying label, and forming adhesive layer on side of label - Google Patents

Abstract

The method involves placing a mold (202) with respect to a micro-injection machine (200), where the mold comprises a cavity whose shape corresponds to the shape of a label to be manufactured. Plastic materials comprising superimposed layers of the label are injected in liquid form into the mold, by the machine. The label is solidified by cooling, and an adhesive layer is formed on a side of the label. A removable protection sheet is formed on the adhesive layer. A thermoplastic film is arranged in inner side of the mold, and a portion of the label is covered.

Description

The present invention relates to the field of labeling of consumer products. It relates more particularly to a method of manufacturing a three-dimensional adhesive injected label.

Background of the Invention and Problems The purpose of labeling any package is to carry information from the manufacturer to the user of the product contained in the package. As the demand for product traceability is increasing, this labeling includes, in particular, data on the origin and manufacture of the product. The best known way at the moment is the use of paper labels, or printing directly on the packaging. Heat shrinkable plastic labels are also known, applied by heating. These labels are most often circumferential, forming a sleeve around the bottle to be labeled. Their use is limited by the resistance to heating both the label and its support.

OBJECTS OF THE INVENTION The objective of the present invention is to propose a new process for the manufacture of injected labels that allows the production of a label that is both usable on surfaces of any shape, that supports an informative content. considerable, and adapts to virtually any support material.

SUMMARY OF THE INVENTION To this end, the invention relates to a method of manufacturing a label intended to be affixed by gluing on a specific labeling surface on a support such as a bottle or a packaging surface, comprising steps of : - placement of a mold comprising an imprint of shape corresponding to the shape of the label to be produced, opposite an injection device, - injection in liquid form of the materials constituting superposed layers of the label in the mold, - solidification of the label, - deposition of a layer of glue on one side of the label, - deposit of a removable protective sheet on said layer of glue

According to an advantageous embodiment, the injection is carried out by a set of micro-injection nozzles, each nozzle being supplied with a plastic material in liquid form of predetermined color and material, the molds being open on a so-called upper face, wherein the nozzles gravity inject plastics in liquid form, the superimposed layers of the label being deposited successively from the deepest, corresponding to the outermost layers of the label, to the upper layers of the mold.

In a particular embodiment, a curing time of an injected plastic material is respected between two successive injections.

In an alternative embodiment, the injection is carried out using an injection molding machine, each mold comprising on the one hand a mobile part and on the other hand a fixed part, arranged facing each other and having a corresponding imprint to the form of the label to be produced, the method comprising steps of: - applying the two faces of the molds against each other under pressure, - injecting plastics under pressure, by an injection assembly comprising a series of injection nozzles of materials in liquid form. solidification by cooling, opening of the mold and demolding of the labels Advantageously, at least one nozzle is connected to an injection cylinder, receiving a liquid to be injected, at least one injection cylinder comprising means for pressurizing the liquid contained in the injection cylinder, controlled by a steering device.

In a particular case of implementation, the method comprises a heating phase of at least one injection cylinder receiving granules of thermoplastic polymer through a hopper, intended to bring the thermoplastic polymer granules to a temperature such that they go into the liquid phase.

The method optionally comprises a step of simultaneous injection of plastics forming different layers of the label.

In implementation variants possibly used in conjunction: the method comprises, before the closing of the mold, a step of placing at least one element overmolding within the mold. the method comprises a step of placing a thermoplastic film, placed inside at least one of the faces of the mold, and covering at least a part of the label.

BRIEF DESCRIPTION OF THE FIGURES The following description, given solely by way of example of an embodiment of the invention, is made with reference to the appended figures which illustrate: FIGS. 1a and 1b: a multi-layer label obtained by a process according to the invention, in an exploded perspective view (FIG. 1a) and in section (FIG. 1b), - FIGS. 2a and 2b: a mold used in the process, in sectional view (FIG. 2a) and in front view (Figure 2b), - Figure 3: a schematic view of a micro-injection machine used in conjunction with a mold as shown in Figure 2, - Figures 4a and 4b: a schematic view of an injection molding machine, used in the case of a multi-injection label embodiment, in the retracted position (FIG. 4a), and in the operating position (FIG. 4b), FIGS. 5a and 5b: a multilayer label obtained by a method multi-injection, in exploded perspective view (FIG. 5a) and sectional view (FIG. 5b), FIG. 6 is a diagrammatic view of an injection molding machine with an insert overmolding device, used in the case of a multi-injection label embodiment comprising an overmoulding; FIGS. 7a and 7b: a multi-layer label obtained by a multi-injection method with insert overmolding and RFID tag inserted between two thicknesses, in exploded perspective view (FIG. 7a) and sectional view (FIG. 7b).

DETAILED DESCRIPTION OF ONE EMBODIMENT OF THE INVENTION A label 100 according to the invention finds its place on any type of packaging, for example on a glass bottle. In the example illustrated here, the label 100 is substantially rectangular in shape and has dimensions of about 5 cm x 15 cm for a thickness of about one to three millimeters. It is however clear that the label according to the invention may have any other shape chosen according to the needs of the user and the nature and geometry of the supports. As shown in FIGS. 1a and 1b, the label 100 comprises several layers, the number and the stack of which may vary from one part to the other of said label 100.

Starting from the so-called lower face of the label 100, intended to come into contact with the object on which it is desired to glue the label, the latter comprises first and foremost a sheet of removable protective paper 106, of known type. in itself. This sheet of protective paper 106, thin and flexible, is intended to be detached before the introduction of the label 100 on its support. The label 100 then comprises a base layer 101, having on at least a portion of its lower face an adhesive thickness 105.

The base layer 101 is made of plastic material such as polyvinyl chloride (known as PVC) or silicone. In the present non-limiting example, the thickness of the base layer 101 is 0.2 millimeters, so as to maintain a high flexibility allowing it to marry many forms of support. This base layer 101 is here chosen as transparent as possible. The glue 105 used here is of a type known per se. It is adapted to the type of support, for example glass or aluminum. However, it is clear that other types of adhesives, known per se, can be used, their choice by those skilled in the art depending on the nature of the support material (glass, aluminum, PET plastic or PVC, "brick "in plasticized cardboard etc.).

In the present example, the base layer 101 comprises an over-volume layer 102. This over-volume layer 102, of thickness 0.3 to 0.4 millimeters, is here colored and made of PVC or silicone. It comprises a recessed portion 104, This over-volume layer 102 supports, in turn, a set of over-volume reliefs 103, also made here of PVC or silicone.

In the example given here in no way limiting, the recessed portion 104 and the reliefs on volume 103 are arranged to form a logo or the name of a product. The over-volume reliefs 103 here have a thickness of between one tenth of a millimeter and a few millimeters.

As can now be seen in FIG. 3, the method for producing a label as described above uses a microinjection machine 200. This comprises, on the one hand, a plate 201 intended for receive one or more molds 202 (see Figs 2a and 2b). These molds 202 are here made of metal, by a method known per se and out as such the scope of the invention. These molds 202 each have a relief imprint 203 corresponding to the shape of the label 100 that is desired to achieve.

The microinjection machine 200 further comprises an injection unit 204. This injection assembly 204 comprises, in the present example, a dozen microinjection nozzles 205, suspended from a support 206. Each of these nozzles 205 is fed by a supply tube 207, made of silicone or liquid PVC, possibly colored. These products are optionally heated to a temperature of a few tens of degrees, depending on their nature. These data are known to those skilled in the art. During the production of the label 100, the molds 202 are arranged on the plate 201 with respect to the injection assembly 204.

Then, the layers forming the label 100 are injected one after the other starting from the deepest layers, which correspond, in the present example, to the reliefs on volume 103, then in realization the layer on top of each other. volume 102, then the base layer 101. For each layer is used the nozzle 205 containing the PVC or silicone product of the nature and the desired color. It is also conceivable to use several injection nozzles simultaneously. The support 206 can be moved laterally above the plane of the plate 201, which can itself move longitudinally. Each nozzle 205 is lowered closer to the mold 202 during its use.

A hardening time is possibly respected between two successive injections, in particular for different materials. This time depends on the thicknesses and materials considered. At the end of the embodiment of the label, a thickness of adhesive 105 is added to the upper part of the mold, then a protective paper film 106 is placed on this thickness of adhesive 105. The labels thus produced are presented in the form of a roll, so as to be compatible in particular with the most conventional bottle label gluing systems.

In an alternative embodiment illustrated by Figures 4 and 5, the label 100 is made using an injection press 301, as schematized Figures 4a and 4b. Such an injection press 301 comprises a plate 302, adapted to receive the movable portion 303a of a mold 303. This movable portion 303a has a cavity 304 corresponding to the shape of a label 100 'to achieve. It is clear that other types of molds can be used without substantially modifying the present method of manufacturing labels. The technique of making these molds is known per se.

The injection molding machine 301 also comprises an injection assembly 305, to which the fixed part 303b of the mold 303 is secured. The injection assembly 305 here comprises a series of injection nozzles 307. Each of these nozzles 307 is connected to an injection cylinder 308, receiving a liquid to be injected.

Each injection cylinder 308 comprises a plasticizing screw 310, controlled by a control device (not shown in the figures). The plasticizing screw 310 is adapted to print a pressure on the liquid contained in the injection cylinder 308. Other injection devices may also be envisaged (injection gun, etc.), in particular according to the characteristics of the molds and the products. to inject. In the present example, some injection cylinders 308 receive granules of thermoplastic polymer through a hopper 309. The receptacle 308 then comprises a heater 311, intended to bring the granules of thermoplastic polymer to a temperature such that they pass into liquid phase. The injection molding machine 301 allows, in an injection cylinder 308 where the material is heated by conduction and shearing (screw-piston), to plasticize the polymer. The injection molding machine 301 also makes it possible to close the mold 303 before the injection, to keep it closed during its filling, while maintaining the pressure that currently reaches 150 MPa. The fixed part 303b of the mold comprises, in the present example of implementation, in no way limiting, a set of bores arranged with respect to each nozzle 307, intended to allow the passage of the liquid polymer to the cavity 304 of the mold 303.

The movable portion 303a of the mold comprises, in the present example, two channels 311, 312, a first end is located in the region of said mold outside the cavity 304, and faces an injection nozzle 307. The second end of each channel is located in the deepest part of said cavity 304. It is clear that a larger number of channels can be formed in the movable portion 303a of the mold. In this way, it is possible to simultaneously inject a polymer into the different parts of the cavity 304, especially both in reliefs on volume 103 ', in a layer on-volume 102' and in a layer basic 101 '. During the cycle, the molten plastic cools from the injection temperature (most often around 200 ° C or higher) to a temperature close to that of the mold, to which the object becomes solid. It is clear that the transformation temperature and the injection pressure depend on the materials and injection techniques considered. In an example given purely for informational purposes, in the case of an injected material of a type known to those skilled in the art under the acronym PLA (bio plastic): the temperature of the molten polymer is approximately 185 ° C. barrel temperature 160 to 190 ° C - the temperature of the mold is of the order of 15 to 35 ° C - the injection pressure can reach 900 Bars - the speed of the injection screw is typically 100-175 turns / minute

In the present example, illustrated by Figures 5a and 5b, the label 100 'made by an injection press comprises a silicone base layer 101' (flexible at room temperature), a thermoplastic polymer over-volume layer 102 ' (Also flexible at room temperature), reliefs in volume 103 'of rigid thermoplastic polymer, a relief in bioplastic 107, PVC elements 108 and a set of letters 109 flexible silicone phosphorescent. It further comprises a thickness of glue 105 and a protective sheet 108.

In another variant embodiment, illustrated by FIGS. 6 and 7, the injection molding machine 301 comprises an articulated arm 320, intended to dispose at predetermined points of the inside face of the fixed part 303b of the mold 303 of the overmolding parts. 110, 111. These overmolding parts 310, 311 are drawn by the articulated arm 320 into distributors 321, 322, of a type known per se.

In this way, it is possible to produce a label as illustrated by FIGS. 7a and 7b, on which the overmolding elements 110, 111 are recognized, the latter comprising an RFID type tag. This overmolding element 111 is here surrounded by a relief element 112, made of silicone or PVC, and for example transparent.

It will be understood that the process described above (or its variants) makes it possible to produce mono-material or multi-material, single-color or multi-color labels. The label thus produced may be embossed and have hollow portions. Its shape, dimensions and thicknesses can be as large as desired. The invention makes it possible to produce injected labels made of flexible and / or rigid thermoplastic polymers, of flexible and / or rigid bioplastics, and / or of silicone, and / or of natural or synthetic elastomer and / or of thermosetting polymers, and The process as described also allows overmolding (with for example object insertion), or overmolding by thermoplastic film. In this case, the method comprises a step of placing a custom thermoplastic film, in color or transparent, with or without a marking, and which is placed in the injection molding machine described above, and covers all or part of the label.

Claims (9)

REVENDICATIONS1. A method of manufacturing a label (100) to be affixed by gluing to a specific labeling surface on a support such as a bottle or a packaging surface, characterized in that the method comprises steps of: - placement of at least one mold comprising an imprint of shape corresponding to the shape of the label to be produced, opposite an injection device, - injection in liquid form of the materials constituting superposed layers of the label in the mold, solidification of the label, - depositing a layer of glue on one side of the label, - depositing a removable protective sheet on said layer of glue. 2. Method according to claim 1, characterized in that the injection is performed by a set of nozzles (205) micro-injection, each nozzle being fed with a plastic material in liquid form of predetermined color and material, the molds (202) being open on a so-called upper face, in which the nozzles (205) inject by gravity plastics in liquid form, the superposed layers of the label (100) being deposited successively starting from the deepest, corresponding to the layers the outermost of the label, towards the upper layers of the mold. 3. Method according to claim 2, characterized in that a curing time of an injected plastic material is respected between two successive injections. 4. Method according to claim 1, characterized in that the injection is carried out using an injection press (301), each mold comprising on the one hand a movable part (303a) and on the other hand a fixed part (303b ), arranged facing each other and having an imprint corresponding to the shape of the label to be produced, the method comprising steps of applying the two faces of the molds against each other under pressure, plastics under pressure, by an injection assembly (305) comprising a series of injection nozzles (307) of materials in liquid form. - solidification by cooling, - opening of the mold and demolding of the labels 5. Method according to claim 4, characterized in that at least one nozzle (307) is connected to an injection cylinder (308), receiving a liquid to be injected, at least one injection cylinder (308) comprising means for pressurizing (310) the liquid contained in the injection cylinder (308), controlled by a control device. 6. Method according to claim 5, characterized in that it comprises a heating phase of at least one injection cylinder (308) receiving granules of thermoplastic polymer through a hopper (309), intended to bring the granules of thermoplastic polymer at a temperature such that they pass into the liquid phase. 7. Method according to any one of claims 4 to 6, characterized in that it comprises a step of simultaneous injection of plastics forming different layers of the label (100). 8. Method according to any one of claims 4 to 7, characterized in that it comprises, before closure of the mold (303), a step of placing at least one element overmoulding (311, 312) within of the mold. 9. Method according to any one of claims 4 to 8, characterized in that it comprises a step of placing a thermoplastic film, placed inside at least one of the faces of the mold, and covering at least part of the label.