EP1516089B1 - Article formed from at least a fibrous material jet comprising at least a null thickness zone and method for making same - Google Patents

Description

The present invention relates to an article comprising a fibrous layer and a structure at least partially transparent or translucent, and the method of manufacturing said article.

The invention relates more particularly to the manufacture of security papers in general, comprising a transparent window.

There may be mentioned in this regard a number of examples from the prior art having a similar structure, but obtained using fairly distant manufacturing methods.

The patent US4462866 discloses a sheet having an elongate member (a wire) inserted into said sheet, said member being exposed at least partially in windows on the surface of the sheet. It is provided that a film or a liquid material such as a varnish, called "overlay", can be affixed to the exposed parts of the wire so as to protect them.

In the patent EP 690 939 or the request WO 95/09274 the Applicant has described a security paper having a transparent window obtained by inserting a plastic film between two jets of fibrous material.

This technique involves embossing two strips of paper in the course of formation, using relief parts integrated into the fabric of a paper machine of round shapes, these reliefs being high enough to prevent the deposition of fibers paper mills in some places of the paper tape.
This results in a through hole for the paper.
Then, two fibrous layers are joined so as to put the hole of a fibrous layer opposite to that of the other layer, the plastic film passing over the superimposed holes.
This results in a transparent window in the paper.

However, this technique has a number of disadvantages.

One of the disadvantages is that the film sandwiched in the paper structure can cause deformations of the sheet. As the sheet is no longer flat, the paper loses on the one hand in aesthetics and on the other hand is difficult to print and / or stack.

• Sur les bords embossés du papier, certains défauts peuvent ainsi apparaître.
• D'une part, les bords ne sont pas réguliers et droits.
• D'autre part, cette méthode par embossage du papier aboutit à un phénomène assez fréquent et difficilement évitable, l'apparition de « barbes », c'est-à-dire de fibres ou fibrilles dépassant des bords, résultant de ce que le papier n'est pas découpé proprement mais repoussé vers l'extérieur. Une fibre ayant réussi à résister à la force de traction de la forme d'embossage reste de ce fait accrochée en partie à la structure fibreuse, la partie restante dépassant du trou ainsi formé.

In addition, this method of forming windows in paper also has the following drawbacks:

• On the embossed edges of the paper, some defects may appear.
• On the one hand, the edges are not regular and straight.
• On the other hand, this method by embossing the paper leads to a fairly common phenomenon and difficult to avoid, the appearance of "barbs", that is to say fibers or fibrils protruding edges, resulting from the fact that the paper is not cut cleanly but pushed outward. A fiber having successfully resisted the tensile force of the embossing form thus remains attached in part to the fibrous structure, the remaining portion protruding from the hole thus formed.

The patent application EP773320 describes a sheet of paper comprising a band placed inside the sheet, in particular as described in the document WO95 / 09274 mentioned above, and combined with a watermark for the sheet to have a substantially constant thickness.

The patent application FR2764314 discloses a sheet having at least one transparent or translucent window, in particular the window can be made by inserting a strip between two sheets, in particular as described in the document WO95 / 09274 mentioned above, the window can cooperate with an element carried on the rest of the sheet when folded to create an authentication.
This prior art has the same disadvantages as the patent EP690939 or the request WO95 / 09274 .

One of the aims of the invention is therefore to eliminate the disadvantages of the prior art as mentioned above.

Another object of the invention is therefore to form a transparent window in a paper based on cellulosic material by cutting or embossing its surface.

To this end, the Applicant proprose no longer apply transparent plastic film inside two fibrous layers, but deposit a structure at least partially transparent or translucent, including a plastic film transparent, a tracing paper or a printed patch having a transparent window, directly on the fibrous layer at the location of the hole formed in the fibrous layer by embossing so as to hide the ill-formed edges of the hole with the aid of opaque portions present previously or deposited laterally on the applied structure and surrounding an area at least partially transparent or translucent thereof.

Another solution envisaged by the Applicant is to form the hole in the fibrous layer with a cutting device downstream of the formation of the fibrous layer, so as to avoid the appearance of the phenomenon of "barbs", and then covering this hole with a structure at least partly transparent or translucent, this structure may be for example a transparent plastic film, a tracing paper or a printed patch comprising a plastic window.

Therefore, the invention relates firstly to an article formed from at least one jet of fibrous material having at least one zone of zero thickness, characterized in that said zone is covered on at least one of its faces. by a structure at least partially transparent or translucent, arranged to reveal a transparent or translucent window in the paper.

In this article, the aforementioned structure is covered with an opacifying substance so as to hide the edges of the hole formed in the fibrous material.

This opacifying substance may be chosen from printing inks, liquid crystals, metal particles, magnetic particles, thermochromic substances and iridescent substances.

Specifically, the structure at least partially transparent or translucent may be a tracing paper, a transparent plastic film or a printed patch comprising a plastic window.

In the case of a patch, the dimensions thereof must be greater than the hole formed in the fibrous material, so that the edges of the hole formed in the fibrous material are hidden by the patch, the edges of the window transparent patch being disposed above the empty space left by the hole formed in the fibrous material.

In a particular way, particularly in the case of an application to valuable or security papers, it will be possible to apply to the at least partly transparent or translucent structure, in particular a plastic film, a tracing paper, or a patch, a substance selected from metal particles, magnetic particles, thermochromic substances, iridescent substances, liquid crystals or mixtures thereof.

Another way of securing said article will also be to apply a diffraction element on said at least partially transparent or translucent structure so as to create a security hologram, which would prevent all the fraudulent copies of the article by reprography by example.

Other protection devices to falsification are possible for the said article.

It is thus possible to provide a step of printing the article in question, once the structure at least partly transparent or translucent filed on the perforated area of the fibrous layer so as to secure the whole point of view of the security of the document.

The hole of the transparent window can also be used to place thick elements, of the order of 100 microns to the thickness of the article.

These thick elements will be placed on the structure at least partly transparent or translucent, whether on the front or back.

Such elements may be, for example, printed circuits, microprocessors, electronic chips, magnetic elements, metal elements, plastic elements, detection devices emitting a signal when they are placed in a suitable electromagnetic or light field.

In the case of electronic circuits, an antenna may be deposited at the same time and coupled to the circuit on the element at least partially translucent or transparent.

These elements may also be thick so as to allow recognition of the document by blind people because of the difference in thickness created.

As a result, a set of discrete and thick particles, such as crystals, metal or plastic particles, or an object having differences in thickness are conceivable at this level.

Although the article obtained by the present invention can perfectly adapt to all types of applications, it is particularly intended for the formation of banknotes, security papers in general, good gifts, documents of value in general, coupons, trademark or product protection labels, traceability labels.

The invention similarly relates to the method of manufacturing said article described below.

• formation d'au moins un jet de matière fibreuse,
• réalisation d'un trou dans la matière fibreuse,
• dépôt de la structure au moins en partie transparente ou translucide à l'emplacement du trou au recto et/ou au verso de la couche fibreuse, de façon à laisser apparaître une fenêtre transparente ou translucide dans l'article.

The method comprises the following steps:

• forming at least one jet of fibrous material,
• making a hole in the fibrous material,
• depositing the structure at least partially transparent or translucent at the location of the hole on the front and / or back of the fibrous layer, so as to reveal a transparent or translucent window in the article.

The structure may comprise at least one of the following elements: a holographic and / or diffractive element, a magnetic, metallic or crystalline coating, liquid crystals, an impression of a varnish or ink, iridescent pigments, thermochromic and / or piezochromic pigments, at least one reflecting surface.

It may also include a plastic film, especially polyester.

The structure will be composed of a single layer or at least two layers, one of which is a carrier layer to be removed upon transfer of the structure to the sheet.

In the latter case, the carrier layer may comprise a plurality of portions of film or fibrous material arranged so that after their transfer on the sheet, these portions are spaced apart from each other on the surface of the sheet.

• une couche porteuse,
• une couche de libération,
• éventuellement une couche de vernis contenant une résine et éventuellement un colorant,
• une couche de métal, de matière plastique ou de matière fibreuse,
• une couche adhésive.

Advantageously, a structure will initially comprise at least the following layers:

• a carrier layer,
• a release layer,
• optionally a layer of varnish containing a resin and optionally a dye,
• a layer of metal, plastic or fibrous material,
• an adhesive layer.

The deposition of the structure at least partly transparent or translucent may be done by hot transfer or cold at the location of the hole on the front and / or back of the fibrous layer, or by against hot or cold gluing on the front and / or back of the fibrous layer.

The hole may be formed either with an embossing roll during the wet phase of the fibrous layer, or with a mechanical cutting device or laser cutting.

Optionally, the article may then be printed or covered with a security substance selected from metal particles, magnetic particles, thermochromic substances, iridescent substances, liquid crystals.

In addition, at least one thick element may be placed on the front and / or back of the at least partially transparent or translucent structure, the thick element being chosen from printed circuits, microprocessors, electronic chips, elements magnetic elements, metal elements, plastic elements, detection devices emitting a signal in the presence of a suitable electromagnetic or light field.

• Les figures 1A et 1B représentent schématiquement et partiellement, respectivement en vue de dessus et en coupe transversale, un article dont le trou a été formé sur forme ronde par embossage,
• Les figures 2A et 2B représentent schématiquement et partiellement, respectivement en vue de dessus et en coupe transversale, un article dont le trou a été formé par découpe laser et recouvert d'un film transparent,
• Les figures 3A et 3B représentent schématiquement et partiellement, respectivement en vue de dessus et en coupe transversale un article recouvert dont le trou a été formé sur forme ronde par embossage et recouvert d'un film plastique transparent et imprimé sur son recto,
• Les figures 4A et 4B représentent schématiquement et partiellement, respectivement en vue de dessus et en coupe transversale un article dont le trou a été formé sur forme ronde par embossage recouvert d'un patch imprimé sur son recto et d'un film transparent muni d'une puce électronique sur son verso,
• La figure 5 est une coupe transversale, schématique et partielle, d'une structure pouvant être utilisée,
• La figure 6 représente schématiquement une installation permettant de réaliser une couche fibreuse comportant des trous formés par embossage,
• La figure 7 illustre schématiquement le contre-collage d'une couche fibreuse et d'une structure, et
• La figure 8 représente schématiquement le transfert d'une structure sur une couche fibreuse, et
• La figure 9 représente schématiquement et partiellement un détail de la figure 8.

The invention will be better understood on reading the following detailed description of nonlimiting exemplary embodiments and on examining the appended drawings, in which:

• The Figures 1A and 1B show schematically and partially, respectively in plan view and in cross section, an article whose hole has been formed on a round shape by embossing,
• The Figures 2A and 2B show schematically and partially, respectively in plan view and in cross section, an article whose hole has been formed by laser cutting and covered with a transparent film,
• The Figures 3A and 3B show schematically and partially respectively in top view and in cross section a covered article whose hole has been formed on a round shape by embossing and covered with a transparent plastic film and printed on its front,
• The Figures 4A and 4B show schematically and partially respectively in top view and in cross-section an article whose hole has been formed on round shape by embossing covered with a patch printed on its front and a transparent film with an electronic chip on its back,
• The figure 5 is a schematic and partial cross-section of a structure that can be used,
• The figure 6 schematically represents an installation for producing a fibrous layer comprising holes formed by embossing,
• The figure 7 schematically illustrates the laminating of a fibrous layer and a structure, and
• The figure 8 schematically represents the transfer of a structure on a fibrous layer, and
• The figure 9 schematically and partially represents a detail of the figure 8 .

We have shown on Figures 1A and 1B a carrier (1) formed of a single fibrous jet, having a through-hole (2) in its surface, formed by means of an embossing roll during wet formation of the sheet.

The fibrous layer (1) is made from cellulose fibers which may optionally contain synthetic or artificial fibers.

We can see that the edges of the hole are irregular, not straight.

Edges of the hole protrude "barbs", pieces of fibers still partially attached to the rest of the fibrous layer and isolated therefrom during the embossing of the hole.

We have shown on Figures 2A and 2B a support (1) formed of a single fibrous jet having a through hole (2) in its surface, formed with a laser, following the formation of the fibrous layer.

It can be seen that the edges of the hole are straight, regular.

The rectangular shape of the hole is fairly faithfully reproduced.

No "beard" is visible to the naked eye.

As a result, the transparent window can be easily obtained for this paper by covering the fibrous layer at the hole with a transparent plastic film 3 on the front as shown in the drawings. Figures 2A and 2B .

The Figures 3A and 3B represent a particular configuration of the invention, in which the single-jet fibrous layer (1) has been perforated by embossing, with appearance of "barbs".

The front side of the fibrous layer is covered with a transparent plastic film (3).

The said film is then covered with an opacifying substance (4) which, here, consists of ink on an area surrounding the hole, so as on the one hand to hide the barbs and on the other hand to leave a transparent area inside the covered hole.

The Figures 4A and 4B show a variant of the invention in which a transparent film (3) is applied to the back and a patch (5) opaque to the front so as to cover the hole, the patch nevertheless having a cut in the middle.

The area covered by the cutting of the patch is placed so as to hide the "barbs" of the fibrous layer.

Since the transparent film itself carries an electronic chip (6) on its surface, it was necessary to fit the chip inside the hole so as to avoid an extra thickness in the article.

In the previous examples, the film (3) consists only of a single layer of transparent plastic material, for example polyester.

It is not beyond the scope of the present invention using a different structure, including a multilayer structure.

• une couche porteuse (10) en polyester,
• une couche de libération (11), par exemple en cire,
• une couche de vernis (12) contenant une résine et éventuellement un colorant,
• une couche métallique (13), par exemple en aluminium,
• une couche adhésive (14) permettant la fixation d'un élément (6) sur la couche fibreuse (1). La couche adhésive (14) peut être à base d'une résine thermofusible, dite « hotmelt ».

For example, there is shown on the figure 5 a composite structure (3 '), comprising:

• a carrier layer (10) of polyester,
• a release layer (11), for example in wax,
• a layer of varnish (12) containing a resin and optionally a dye,
• a metal layer (13), for example of aluminum,
• an adhesive layer (14) for fixing an element (6) to the fibrous layer (1). The adhesive layer (14) may be based on a hot-melt resin, called "hotmelt".

In the example described, the carrier layer (10) has a thickness of about 12 microns and the cumulative thickness of the layers (11) to (14) is about 2 to 3 microns.

The layers (12), (13) and (14) form a film (3 ") to be transferred onto the sheet (1).

The structure (3 ') is also called "foil" and it allows to assemble the film (3 ") with the sheet (1), for example by hot pressing, operation during wherein the release layer (11) melts and allows separation of the carrier layer (10) from the other layers. The heat provided during this operation also causes the activation of the adhesive layer (14), in order to heat-seal the film (3 ") on the sheet (1).

The metal layer (13), made of aluminum, for example, may have a surface appearance to reflect light through the layer of colored varnish (12), thereby creating a color effect on the surface of the article.

The layer (12) may have a hologram consisting of a diffraction grating. The latter can be produced by means of a matrix of a transfer machine for transferring the film (3 ") onto the sheet (1), alternatively, the hologram can be produced before the layer is assembled ( 12) with the other layers.

The metal layer (13) can be replaced by a plastic layer.

The film (3) or (3 ") can completely cover or not a face of the article.

The film (3) or (3 ") can extend continuously or not between two opposite edges of the article.

The film (3) or (3 ") can form a patch on the article.

We will now describe with reference to the figure 6 a method for producing a fibrous layer having at least one through hole.

Partially and schematically represented on the figure 6 two round-shaped paper machines (35) and (36).

The first machine (35) comprises a tank (37) containing a suspension of fibers, for example cellulose fibers, in which is partially immersed a rotating roll cylinder (38) defining a surface (39) in contact with which is formed continuously a jet of paper (40) taken by a pick-up felt (42). The surface (39) has embossing in relief, so as to create in the first jet (40) through holes.

The second machine (36) comprises, like the machine (35), a tank (37), a rotating fabric cylinder (44) defining a surface (47) in contact with which forms a second jet of paper .

The surface (47) of the web roll (44) has a raised embossing so as to create holes (46) in the second jet, the holes (46) being arranged to overlap with the holes (45) of the web first jet during the assembly of the two jets, obtained during the passage of the two jets between the round shape (44) and a rotary cylinder (48).

Such an installation is in particular described in more detail in the European patent EP 0687 324 .

The sheet can be cut later to the format of the article to be produced.

The cavity can be made by other means, for example using a laser or mechanical abrasion.

The film and the sheet can be combined in many ways without departing from the scope of the invention.

On the figure 7 schematically shows the assembly by laminating a film (3) and a fibrous layer (1) by passage between two rotary cylinders (50) and (51). In this figure, the film (3) is previously brought into contact with a gluing machine (53).

The film (3) and the sheet (1) can then be positioned relative to each other by registration, so that an opaque portion on the film comes to cover the edges of the cavity formed in the sheet ( 1). The film (3) remains permanently on the sheet (1), in the example considered.

In the case of the composite structure (3 '), the film (12), (13), (14) can be transferred, for example hot, onto the sheet (1), as illustrated in FIGS. Figures 7 and 8 .

In such a transfer method, the sheet (1) and the structure (3 ') can be driven with the carrier layer (10), (11) moving in the same direction by means of a machine comprising a first rotary cylinder. (55) carrying dies (56) and a second rotating cylinder (57). The film (12), (13), (14) and the sheet (1) can be assembled when passing between the cylinders (55) and (57). We can see on the figure 8 after passing between the rotating cylinders (54) and (57), the carrier layer and the release layer are separated from the other layers (12), (13) and (14), transferred to the sheet (1).

The film (12), (13), (14) can also be fed between a matrix (56) and the sheet (1) in a direction generally transverse to the displacement of the sheet, as described in the European patent. EP 0 473 635 .

Of course, the invention is not limited to the implementation examples which have just been described.

Each through cavity can be closed on one side only by a film, or on both sides by two films.

Each through cavity can also be closed on one side by a film and on the other by a fibrous layer.

In particular, when an element is placed in the cavity of the sheet by transfer, the layer of the structure carrying the element may be based on fibrous material.

Claims (21)

1. Article formed from at least one ply of fibrous material (1) including at least one transparent or translucent window, characterised in that said ply (1) includes at least one region of zero thickness (2), said region (2) being covered on at least one of its faces by an at least partially transparent or translucent structure (3, 5) disposed in such a way as to reveal said transparent or translucent window in said ply of fibrous material, the structure (3, 5) being covered with an opacifying substance (4) in such a way as to conceal the edges of said region of zero thickness (2) formed in the fibrous material (1).
2. Article according to Claim 1, characterised in that the opacifying substance (4) is selected from printing inks, liquid crystals, metal particles, magnetic particles, thermochromic substances, iridescent substances.
3. Article according to any one of the preceding claims, characterised in that the structure (3) is a transparent plastic film.
4. Article according to either of Claims 1 and 2, characterised in that the structure (3) is a tracing paper.
5. Article according to Claim 1, characterised in that the structure (5) is a printed patch which includes a cut-out.
6. Article according to Claim 5, characterised in that the patch (5) is dimensioned larger than said region of zero thickness (2) formed in the fibrous material (1), so that the edges of said region of zero thickness formed in the fibrous material are concealed by the patch, the edges of the cut-out of the patch being disposed above the empty space left by said region of zero thickness formed in the fibrous material.
7. Article according to Claim 6, characterised in that the patch (5) is covered by a security substance selected from metal particles, magnetic particles, thermochromic substances, iridescent substances, liquid crystals and mixtures thereof.
8. Article according to any one of the preceding claims, characterised in that the at least partially transparent or translucent structure (3,5) defines a security hologram.
9. Article according to any one of the preceding claims, characterised in that it defines an article selected from a banknote, a security paper, a gift voucher, a value document, a coupon, a label protecting a brand or product and a traceability label.
10. Method for producing an article according to any one of the preceding claims, characterised in that it includes the following steps:

    - formation of at least one ply of fibrous material (1),

    - production of a region of zero thickness (2) in the fibrous material,

    - deposition of the at least partially transparent or translucent structure (3, 5) at the location of said region of zero thickness on the front side and/or the reverse side of said ply of fibrous material so as to reveal a transparent or translucent window in the article.
11. Method according to Claim 10, characterised in that the structure (3, 5) includes at least one of the following elements: a holographic and/or diffractive element, a magnetic, metallic or crystalline coating, liquid crystals, printing with a lacquer or an ink, iridescent pigments, thermochromic and/or piezochromic pigments, a reflective surface.
12. Method according to either of Claims 10 and 11, characterised in that the structure comprises a film of plastics material, in particular of polyester.
13. Method according to any one of Claims 10 to 12, characterised in that the structure is composed by a single layer.
14. Method according to any one of Claims 10 to 12, characterised in that the structure comprises at least two layers, one of which is a carrier layer designed to be removed during the transfer of the structure on to the ply of fibrous material.
15. Method according to Claim 14, characterised in that the carrier layer comprises a plurality of portions of film or of fibrous material disposed in such a way that, after being transferred on to the ply of fibrous material, these portions are spaced apart on the surface of said ply of fibrous material.
16. Method according to either of Claims 14 and 15, characterised in that a structure (3') initially comprising at least the following layers:

    - a carrier layer (10),

    - a release layer (11),

    - optionally a layer of lacquer (12) containing a resin and optionally a colorant,

    - a layer of metal (13), of plastics material or of fibrous material,

    - an adhesive layer (14),
    is brought into contact with said ply of fibrous material.
17. Method according to any one of Claims 14 to 16, characterised in that the deposition of the at least partially transparent or translucent structure (3, 5) is effected by hot or cold transfer at the location of said region of zero thickness on the front and/or reverse side of the fibrous layer (1).
18. Method according to any one of Claims 10 to 12, characterised in that the deposition of the at least partially transparent or translucent structure (3, 5) is effected by hot or cold lamination on the front and/or reverse side of said ply of fibrous material (1)
19. Method according to any one of Claims 10 to 18, characterised in that said region of zero thickness (2) is formed with the aid of an embossing roller (38, 44) during the wet forming of said ply of fibrous material (1).
20. Method according to any one of Claims 10 to 18, characterised in that said region of zero thickness (2) is formed by a mechanical or laser cutting device.
21. Method according to any one of Claims 10 to 20, characterised in that at least one thick element (6) is placed on the front and/or reverse side of the structure (3, 5), the thick element being selected from printed circuits, microprocessors, electronic chips, magnetic elements, metal elements, plastics elements, detection devices which emit a signal in the presence of a suitable electromagnetic or light field.

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