Watermarked strip or sheet of paper and manufacturing method thereof

Abstract

The invention relates to a watermarked strip or sheet of paper (1) comprising at least two separate watermarks (2; 3) each formed of characters and having respective directions of reading that form an angle of 90° to one another, the watermarks being arranged on the vellum (11) in such a way that it is possible to connect at least one point of at least one of the watermarks to any character of the other watermark by exclusively passing through an unwatermarked region of the vellum.

Description

[0001] Description

[0002] Title: Watermarked paper strip or sheet, and manufacturing process

[0003] Technical field

[0004] The present invention relates to watermarked papers and methods of making such papers.

[0005] Prior art

[0006] Security documents, like some high-end printing, writing or art papers, very often have watermarks formed during the paper manufacturing process.

[0007] These watermarks can define a pattern in light, dark, with one or more tones, when the paper is observed in transmitted light.

[0008] For some applications, the pattern includes a sequence of characters, for example alphanumeric, which assume a predefined orientation of the paper when reading.

[0009] Paper can be packaged and delivered in roll form or in reams of large sheets for cutting into smaller sheets, generally rectangular in size.

[0010] It is then necessary to respect a certain orientation of the paper when cutting the sheet if we want the watermark and the printing to have the same reading direction, which can complicate the cutting and printing process, and generate additional costs as well as risks of errors.

[0011] Furthermore, it is often desirable that the watermark(s) do not interfere with the rendering of the print under certain viewing conditions of the printed paper.

[0012] Summary of the invention

[0013] The invention aims to address this problem and achieves this by proposing a watermarked strip or sheet of paper comprising at least two separate watermarks, each formed of characters and having respective reading directions forming an angle of 90° between them, the two watermarks being arranged on the vellum in such a way that it is possible to connect, for at least one of the watermarks, at least one point of it to any character of the other watermark by exclusively traversing a non-watermarked area.

[0014] Thanks to the invention, there are at least two possible reading orientations at 90° to each other of the watermarks, which makes it possible on the one hand to produce a print either in landscape format or in portrait format, and on the other hand to always have a watermark on both which has the same reading direction as the print.

[0015] This simplifies the cutting and printing process, since it is no longer necessary to respect a particular paper cutting orientation to ensure that the print has the same reading direction as the watermark. Especially when printing takes place after cutting, it is sufficient to respect the direction of insertion of the paper into the printer.

[0016] The arrangement according to the invention also makes it possible to facilitate authentication by watermark, in particular by making it accessible to a wider public; it thus makes it possible to extend the use of watermarks in particular to papers usually devoid of watermarks such as papers for advertising or communication purposes (notepads, product sheets, etc.).

[0017] By "reading direction" is meant the direction in which the characters are read successively by a normal observer to give the expected meaning to this sequence of characters; for example, for a sequence of Latin alphanumeric characters normally read from left to right, the reading direction corresponds to the direction in which the word is written, starting from the first character to the last. Reading orientations forming an angle of 90° between them can correspond to two watermarks, the orientation of one of which corresponds to that of the other after a 90° rotation, clockwise or counterclockwise. The characters can be characters from the Arabic, Cyrillic, Greek, Hebrew, Japanese, Latin, Chinese, etc. alphabets.

[0018] Furthermore, there remains on the paper an extended unwatermarked surface (vellum), which is not likely to interact optically with the print to modify its rendering. The extent of the vellum can correspond, for example, to more than 50% of the total surface of one side of the sheet or strip, better still to more than 70%.

[0019] One of the watermarks is preferably oriented in the machine direction and the other in the cross direction. This simplifies cutting, which can be done in both the cross and machine directions. The "machine direction" refers to the direction in which the paper web is fed during production. The cross direction is perpendicular to it.

[0020] The strip or sheet may be intended to receive or include printing having the same reading direction as one of the watermarks. This may be handwritten printing, or printing carried out using a digital or non-digital printer, for example using a printing technique chosen from inkjet, laser, intaglio and offset printing, flexographic printing and rotogravure printing.

[0021] Paper

[0022] The paper according to the invention may be based on plant and / or synthetic fibers of all kinds, and may or may not be made from cotton fibers.

[0023] Its weight, measured according to the ISO 536:2019 standard, can be between 40 and 200 g / m 2 .

[0024] H can be white or colored, single-jet or double-jet, coated or not, covered with a matt or glossy varnish.

[0025] H may have undergone surface treatment with a biocidal composition. It may or may not incorporate safety markers.

[0026] Watermarks

[0027] The watermarks may comprise alphanumeric characters, but the invention is not limited to such watermarks, and characters from various alphabets may be used. Each watermark may be formed by a word of one or more letters, belonging to the same font or not, of the same size or not. The number of characters in a watermark is for example at least 1, being for example between 2 and 10. The watermark may comprise acronyms having a particular meaning such as "™", "®" or "©", to indicate that the word is a trademark for example. The watermark may be devoid of any graphic sign other than a character from a recognized alphabet or one of the acronyms above. The characters may appear in a stylized form or as ideograms, if applicable.

[0028] The watermarks according to the invention may comprise, in addition to the characters from which they are formed, at least one image, for example so as to form a logo.

[0029] The watermarks may be identical up to a 90° rotation. This simplifies manufacturing, as it is possible in this case to use identical "galvanos" fixed on the paper forming fabric with orientations at 90° to each other, or alternatively the same fabric embossing tool or identical fabric embossing tools, said embossing tool(s) being used at orientations at 90° to each other. By "embossing tool" is meant in particular a plate provided with a relief intended to be transferred to the paper forming fabric, said embossing tool preferably further comprising a counter-plate which may be provided with a relief forming a counterpart to the relief of said plate. Where appropriate, the manufacturing fabric is embossed by being placed between said plate and said counter-plate.

[0030] All watermarks on the paper can be identical to each other up to a 90° rotation.

[0031] The interval w between the two watermarks may be greater than or equal to 20 mm, preferably 30 mm and more preferably 50 mm. This variant is economically advantageous compared to the production of watermarks in semi-circular form because it limits the operations of embossing the manufacturing canvas and / or fixing "galvanos" on the manufacturing canvas. By making the watermarks stand out in this way compared to the vellum, this variant also helps to facilitate authentication because the public's eye will be more easily attracted by watermarks arranged in this way than by semi-circular watermarks which form a homogeneous visual impression on the paper.

[0032] Watermarks can be light, dark, single-tone or multi-tone. They are made, for example, by embossing the canvas and / or using "galvanos" (also called "electrotypes").

[0033] Each watermark may have a larger dimension, in the sense of the word formed by the characters in particular, between 10 and 100 mm, preferably between 20 and 80 mm, and more preferably between 40 and 80 mm and occupy a surface area of ​​between 1 and 50 cm 2 , preferably between 2 and 16 cm 2 , and more preferably between 4 and 16 cm 2 .

[0034] The strip or sheet may be devoid of any security element other than the watermark. Alternatively, the sheet may include at least one security element other than the watermark.

[0035] The strip or sheet may not contain any watermark other than the two watermarks mentioned above.

[0036] The two watermarks may each consist of the same sequence of characters, which are found in their entirety on the sheet; alternatively, one of the watermarks originally contains the same sequence of characters on the strip as the other, but due to the cutting of the strip to form the sheet, this sequence of characters is found to be incomplete on the sheet. Alternatively, the two watermarks originally contain the same sequence of characters on the strip, but this sequence is found to be incomplete, for the part of each of the watermarks which remains visible on the sheet, due to the cutting of the strip to form the sheet. The cutting of the strip may be carried out in a manner marked or not in relation to the watermarks.When the cutting is carried out in an unmarked manner, the interval between the watermarks is preferably less than that existing between the cutting lines, so as to ensure the presence of at least part of a watermark of a given orientation, on each sheet.

[0037] On the tape, watermarks can follow one another at regular intervals, for example between 50 and 250 watermarks per m 2 .

[0038] The paper strip can be between 1 and 10 m wide and more than 1 km long, for example.

[0039] A sheet produced by cutting the strip may be rectangular or other in shape, and may have, for example, sides with dimensions between 4 and 100 cm, preferably between 10 and 30 cm.

[0040] A large sheet, produced by cutting the strip, can itself, if necessary, be subsequently re-cut to a smaller format, and form one or more new sheets according to the invention.

[0041] A sheet may contain, where appropriate, at least two inverted watermarks, so that the sheet must be turned 180° to maintain the same reading direction from one watermark to the other. In particular, it is possible to have on the strip or sheet at least four watermarks with respective orientations of 0°, 90°, 180° and 270°, and to ensure that at least part of these four watermarks is always found on the sheet after cutting. In this case, it is guaranteed to always have a part of at least one watermark which has the same reading direction as the printing, whether this is done in portrait or landscape mode, and whatever its orientation in which it is inserted into the printer.

[0042] Manufacturing process

[0043] The invention also relates to a method for manufacturing a sheet of paper according to the invention, as defined above, in which a strip of watermarked paper is manufactured in which the watermarks are repeated in the machine direction at regular intervals, a method in which the strip is cut to form at least one sheet comprising at least part of a watermark of each orientation.

[0044] To make the watermarks, at least two identical galvanos can be used, arranged with 90° orientations between them.

[0045] To produce the watermarks, at least two identical galvanos or embossing tools may be used, arranged with orientations at 90° to each other. The invention also relates to a method of printing a sheet obtained by the above method, in which the sheet obtained is printed by forming an impression having the same reading direction as the watermark.

[0046] Brief description of the drawings

[0047] The invention may be better understood by reading the detailed description which follows, non-limiting examples of its implementation, and by examining the attached drawing, in which:

[0048] [Fig 1] Figure 1 shows schematically and partially in front view a strip of paper according to the invention,

[0049] [Fig 2] Figure 2 illustrates the cutting in the strip of sheets in rectangular format with the long side oriented in the cross direction,

[0050] [Fig 3] Figure 3 illustrates the cutting in the strip of sheets in rectangular format with the long side oriented in the machine direction,

[0051] [Fig 4] Figure 4 represents in isolation a sheet according to the invention, with printing in portrait mode,

[0052] [Fig 5] Figure 5 represents the sheet of Figure 4 in isolation, with a landscape mode print,

[0053] [Fig 6] Figure 6 represents another example of a sheet according to the invention, and

[0054] [Fig 7] Figure 7 illustrates an example of the arrangement of galvanos on the paper machine fabric.

[0055] Detailed description

[0056] Figure 1 partially shows a strip of paper 1 according to the invention. This strip 1 may have a length, for example, greater than 1000 m, only a section of it being visible in the figure. It may come from a roll previously produced by the paper machine or be in the process of being produced by the latter.

[0057] The strip 1 is formed by a conventional papermaking technique, and in accordance with the invention has watermarks 2 and 3 having respective reading orientations at 90° to each other. Thus, in the example illustrated in Figure 1, the reading direction of the watermarks 2 is from left to right, while the watermarks 3 only have the same reading direction after a counterclockwise rotation of the paper. In the example illustrated, the watermarks 2 and 3 comprise the character sequence "VWXYZ" but the invention applies to any character sequence, alphanumeric or otherwise. The interval w between the two closest watermarks 2 and 3 is for example between 30 and 100 mm.

[0058] The web 1 is used for the production of sheets 4 intended to be printed, and the cutting of the sheets in the web can be carried out in various ways, as illustrated in figures 2 and 3, the latter representing only one possible example of cutting among many possibilities.

[0059] The sheets 4 may be rectangular in format, and may be cut so as to have their long side 5 perpendicular to the machine direction M, as illustrated in figure 2, or parallel to it, as illustrated in figure 3.

[0060] The cutting of the sheets 4 is done in such a way as to preserve at least a part of a watermark 2 and at least a part of a watermark 3, and better still at least one entire watermark 2 and at least one entire watermark 3, as illustrated in figures 4 and 5. On the latter, each sheet 4 has a single watermark 2 and a single watermark 3, both whole.

[0061] The at least partial presence of a watermark of each orientation on sheet 4 makes it possible to print in portrait or landscape mode while having one of the watermarks retaining the same reading direction as the print.

[0062] As an example, Figure 4 illustrates printing in portrait mode, i.e. with the long side 5 vertical when reading; we see that the reading direction is the same for print 6 and watermark 3. In Figure 5, we printed in landscape mode, and the reading direction is then the same for print 6 and watermark 2.

[0063] In the examples of figures 4 and 5, the large side 5 is oriented parallel to the machine direction M, but as a variant, the large side 5 could be oriented perpendicular to the machine direction M.

[0064] In Figures 4 and 5, there is only one watermark 2 and 3 per sheet 4, and each is whole.

[0065] It is not outside the scope of the present invention when, on each sheet 4, the watermarks which appear in transmitted light constitute, for at least one of them, only a fraction of the watermarks 2 or 3, as illustrated in FIG. 6. The vellum 11 occupies a large fraction of the surface of the strip 1, and extends in particular between the watermarks 2 and 3.

[0066] In Figure 4, we see that if we take a point of a watermark, in this case watermark 2, each straight line D which connects this point to a character of the adjacent watermark 3, remains on the vellum 11 and does not cross any area which would be occupied by a third watermark, other than watermarks 2 and 3 in question.

[0067] To produce strip 1, the forming fabric of the paper machine, which is for example a Fourdrinier type machine fabric, can be equipped with identical galvanos 13, but oriented at 90° to each other, to form watermarks 2 and 3.

[0068] Of course, the invention is not limited to the examples which have just been described.

[0069] For example, the machine used to form the paper may be a flatbed machine. Alternatively, the watermarks may be formed using a watermarking roller.

[0070] The paper may not contain security features other than watermarks, and may be intended for writing, printing or decorative arts, or for making packaging, envelopes, paper bags, wallpaper or gift wrap.

[0071] Alternatively, it includes at least one security element other than a watermark, for example a security thread or a print of optically variable ink, and more generally any first, second or third level security element.

Claims

Demands 1. Watermarked strip or sheet of paper (1) comprising at least two separate watermarks (2; 3) each formed of characters and having respective reading directions forming an angle of 90° between them, the watermarks being arranged on the vellum (11) in such a way that it is possible to connect for at least one of the watermarks at least one point of it to any character of the other watermark by traversing on the vellum exclusively a non-watermarked area.

2. Strip or sheet according to claim 1, one of the watermarks being oriented in the machine direction (M) and the other in the cross direction.

3. Strip or sheet according to any one of claims 1 and 2, the watermarks (2; 3) comprising alphanumeric characters.

4. Strip or sheet according to any one of claims 1 to 3, the watermarks (2; 3) being identical up to a rotation of 90°.

5. Strip or sheet according to any one of the preceding claims, all the watermarks (2; 3) of the paper being identical to each other up to a rotation of 90°.

6. Strip or sheet according to any one of the preceding claims, comprising an impression (6) having the same reading direction as one of the watermarks.

7. Strip or sheet according to any one of the preceding claims, the interval (w) between the two watermarks being greater than or equal to 20 mm.

8. Strip or sheet according to any one of the preceding claims, the watermarks (2; 3) being clear watermarks.

9. Strip or sheet according to any one of the preceding claims, being devoid of any other security element than the watermark.

10. Method of manufacturing a sheet (4) of paper according to any one of the preceding claims, wherein a watermarked paper strip (1) is manufactured in which the watermarks (2; 3) are repeated in the machine direction (M) at regular intervals, method wherein the strip is cut to form at least one sheet (4) comprising at least a part of a watermark of each orientation.

11. Method according to the preceding claim, wherein to produce the watermarks (2; 3) at least two identical electroplaters (13) or at least two identical embossing tools are used, arranged with orientations at 90° to each other.

12. Method of printing a sheet (4) obtained by the method according to any one of claims 10 and 11, wherein the sheet obtained is printed by forming an impression (6) having the same reading direction as one of the watermarks (2; 3).

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