EP2031127B1 - Method for creating an opening in a multiple layer safety paper - Google Patents

Description

The invention relates to a method for producing a passage opening in a multilayer security paper.

Security papers or documents of value are often provided with security features, such as watermarks, embedded security threads and the like, which make it possible to check the authenticity of the security paper or value document and at the same time serve as protection against unauthorized reproduction.

For the purposes of the invention, the term "security paper" here refers to the unprinted paper, which is usually in quasi-endless form and is further processed at a later time. A "document of value" is a document that has been completed for its intended use. Value documents within the meaning of the present invention are, in particular, bank notes, shares, bonds, certificates, vouchers, checks, high-quality admission tickets, but also other papers which are subject to counterfeiting, such as passports and other identification documents, as well as product security elements such as labels, seals, packaging and the like. The simplified term "security paper" or "value document" below includes all such documents and product security means.

In the past, in particular, such authenticity features have proven themselves that can only be introduced into the security paper during production. A first type of authenticity features, such as watermarks, security threads, chemically-reactive additives or mottled fibers, serve for visual authentication by a human. Although these features are visually recognizable, they guarantee a high degree of safety, since the paper equipped with such authenticity features can only be produced with complex machines to which a counterfeiter has no access and whose purchase or replica is not economically worthwhile for counterfeiting purposes.

In addition to features that can be identified visually and without aids, security papers have for a long time also been provided with authenticity features of a second type, which can only be detected by means of special detection devices. With this type of features, a forger additionally has the problem of having to identify the presence of a feature and its special properties.

Many security papers and documents of value contain authenticity features of both types mentioned in order to enable an authenticity check at various levels. For example, a security thread for embedding in banknotes or other value documents may have a visually recognizable negative light in transmitted light and additionally a machine-readable magnetic code.

pamphlet EP 0 825 297 A1 discloses a method for defining a through hole having the features of the preamble of claim 1.

Based on this, the present invention seeks to propose a method for producing security paper with high security against counterfeiting.

This object is solved by the features of the independent claims. Further developments are the subject of the dependent claims.

Hereinafter, in addition to the embodiments according to the invention also further, not even belonging to the invention embodiments are described, which serve to better understand the invention and the advantages associated with the invention.

Multi-ply security paper is a security paper combined from several layers, whereby the merging of the layers can take place already with the papermaking or only after the papermaking. In both variants, there are several different principles according to which the security paper can be equipped with one or more authenticity features. Foreign elements can be applied to the security paper, visually or machine-controllable measures can be taken on the individual layers that make up the multilayer security paper, and intercalations between two or more of the individual layers can be introduced.

The multilayer security paper contains at least one layer of paper. The further layers can likewise be made of paper, but also of other materials, for example by plastic films.

The foreign elements can be applied, for example, glued, both during and after paper production in endless form, such as strips or tapes, or in the form of label-shaped individual elements on the security paper. For interlayer intercalations, individual elements such as fibers, planchettes, pigments, imprints and the like, or continuous materials such as security threads, security tapes, nets, meshes, fabric material or film webs may be considered.

In papermaking, a variety of measures to be taken on the individual layers of paper offer. For example, the individual layers can have a total or even only partially different thickness or different composition. The latter can be achieved for example by additives in the production of individual layers or by forming the individual layers of different fibers. Furthermore, the individual layers can have a different surface structure. These include, for example, authenticity features, such as through openings, watermarks or interruptions, in one or more of the individual layers. Subsequent deformation of the paper layers, for example with the aid of a dandy cutter, is also possible.

If the paper layers are joined to one another by laminating only after papermaking, then authenticity features can be produced on the one hand with the measures just mentioned, ie in particular by varying the thickness, the composition or the surface structure of the paper layers. Additional possibilities arise when different materials, such as paper and plastic films, are combined. One, several, or even all of the different material layers can then be provided with authenticity features, wherein a particularly high protection against counterfeiting is achieved when the authenticity features of different layers enter into a functional correlation with each other. For example, the information present in different layers may be complementary to a total information, or the effect of an authenticity feature of one layer may presuppose the presence of another feature in another layer.

In a multi-ply security paper for the production of security or value documents, such as banknotes, identity cards and the like, which itself is not part of the invention, an endless security element is introduced into a first paper ply, which is freely accessible on at least one side of the paper ply. The first paper layer is on the freely accessible Side of the security element covered by a second paper layer, which has one or more openings in the region of the security element. Preferably, the extent of the opening (s) perpendicular to the running direction of the endless security element is smaller than its width so that it does not extend beyond the security element.

The endless security element can be formed in particular by a security thread or a wide security band. Security threads have a width of 2 mm or less, usually about 1 mm. Wider endless security elements are referred to as security bands in the context of this description. In particular, they have a width of 4 mm to 20 mm, sometimes even up to 30 mm.

While the narrower security threads are mostly embedded in the first paper layer, the wide security tapes typically divide the first paper layer into two parts so that they are visible and accessible on both sides of the paper layer. In this case, a characteristic deckle edge is advantageously formed in the edge regions of the security band, which is not reproduce by cutting or punching. The security element may also be fastened with an adhesive in the first paper layer.

The endless security element can moreover be equipped with optically variable effects, in particular with a diffraction structure, a hologram, a color shift effect or another interference layer effect. It can also be provided with a printed image, in particular positive or negative characters.

The opening of the second paper layer may, for example, in the form of a strip-shaped extending along the endless security element Interruption be provided. Such an interruption can be closed during production with a rupturable release strip, so that an initially closed security paper is formed into which an opening can be made at a later time. Any other hole shapes are eligible for the openings, such as a regular sequence of round or square interruptions. In an advantageous embodiment, the openings in the second paper layer are filled with a transparent material, in particular a polyurethane adhesive.

According to an advantageous embodiment of the security paper, the first paper layer contains a watermark and the second paper layer in the region of the watermark contains an interruption in which the watermark clearly emerges.

In an advantageous variant, the first paper layer has a grammage of 60 to 80 g / m ² , in particular of 65 to 70 g / m ² , while the second paper layer has a grammage of 15 to 45 g / m ² , in particular from 20 to 25 g / m ² . In another, likewise advantageous variant, the conditions are reversed, and the first paper layer has a grammage of 15 to 45 g / m ² , in particular from 20 to 25 g / m ² , while the second paper layer has a grammage of 60 to 80 g / m ² , in particular from 65 to 70 g / m ² .

• eine erste Papierbahn gebildet wird, und ein endloses Sicherheitselement so in die erste Papierbahn eingebracht wird, dass das endlose Sicherheitselement zumindest auf einer Seite der Papierbahn frei zugänglich ist,
• eine zweite Papierbahn gebildet wird, die im noch feuchten Zustand mit der ersten Papierbahn zusammengeführt und fest verbunden wird, so dass sie die frei zugängliche Seite des Sicherheitselements abdeckt,
• wobei in die zweite Papierbahn eine oder mehrere Öffnungen eingebracht werden, die nach dem Zusammenführen mit der ersten Papierbahn im Bereich des endlosen Sicherheitselements zu liegen kommen.

In a method for producing a security paper described above, which itself is not part of the invention, it is provided that

• a first paper web is formed, and an endless security element is introduced into the first paper web such that the endless security element at least on one side of the paper web is freely accessible,
• a second paper web is formed, which is brought together in the still wet state with the first paper web and firmly connected so that it covers the freely accessible side of the security element,
• wherein in the second paper web one or more openings are introduced, which come to rest after merging with the first paper web in the region of the endless security element.

The production of the first and / or second paper web advantageously takes place in a DC round wire paper machine. Alternatively or additionally, the first and / or second paper web can be produced in a short former in which the paper pulp is sprayed onto a round screen.

In a particularly advantageous development of the method, the second paper web is produced on a round screen, the holes of which are closed in partial areas. As a result, the sheet formation is suppressed in these sub-areas and there are fiber-free areas, so openings, in the second paper web. The closing of the holes can be done with advantage by applying, in particular sticking a cover strip, by partial printing of the screen with a lacquer layer or by a voltage applied from the inside of the lateral surface of the round cover ring. It is also possible to run the endless security element in the papermaking on the round screen so that it closes the holes of the round screen at the accumulated places.

In another multi-ply security paper for the production of security or value documents, such as banknotes, identity cards and the like, which itself is not part of the invention, at least two paper layers produced with different fibers are combined with one another. The at least two paper layers can be formed in particular from fibers of different colors, different lengths or fibers with different feature additions.

In one embodiment, the paper layers produced with different fibers are formed with mutually complementary interruptions and complement each other to form a combination paper. This combination paper layer has no greater thickness than the individual layers, since the contributions of the individual layers to the combination paper layer are arranged in each case in interruptions of the other paper layers. In the simplest case, the paper layers consist of two complementary stripe patterns, so that the combination paper layer results in an alternating sequence of strips of the two individual paper layers.

In another embodiment, the at least two layers of paper produced with different fibers have interruptions in the form of vertical or horizontal strips and are arranged one above the other in the security paper, so that they form a checkerboard pattern.

In another advantageous embodiment, a first, watermark-containing paper layer is formed from short fibers and combined to increase the tear strength with a second thinner paper layer of long fibers. Advantageously, the first paper layer of short fibers is even sandwiched between two thinner paper layers with long fibers. Thereby the high tear strength of the long fiber layer (s) is combined with the pronounced watermark effect of the short fiber layer.

In a further advantageous embodiment, a first paper layer containing a watermark is covered by a second paper layer, which is formed in the region of the watermark with transparent fibers and outside the watermark region with ordinary, non-transparent fibers. The watermark is then protected by the transparent fiber area and yet clearly visible.

It is understood that the at least two paper layers produced with different fibers can be combined with further full-surface or interrupted paper layers. They can also be combined with a security element, which is preferably visible through the paper layers at least in a partial area, for example an opening.

• in einer ersten Nasspartie einer Papiermaschine eine erste Papierbahn gebildet und gegebenenfalls mit Individualisierungsmerkmalen, wie einer Öffnung oder einem Wasserzeichen, versehen wird,
• in einer zweiten Nasspartie einer Papiermaschine eine zweite Papierbahn gebildet wird,
• die zweite Papierbahn über ein Abnahmeband mit der ersten Papierbahn zusammengeführt und fest verbunden wird, und bei dem
• aus der zweiten Papierbahn mittels einer Saugvorrichtung im noch feuchten Zustand Papierfasern, vorzugsweise im Register zu den Individualisierungsmerkmalen der ersten Papierbahn, entfernt werden.

In another method for producing a security paper, which itself is not part of the invention, it is provided that

• in a first wet end of a paper machine, a first paper web is formed and optionally provided with individualization features, such as an opening or a watermark,
• in a second wet end of a paper machine, a second paper web is formed,
• the second paper web is brought together via a removal belt with the first paper web and firmly connected, and in which
• be removed from the second paper web by means of a suction device in the still wet state paper fibers, preferably in register with the individualization features of the first paper web.

The suction device may be a perforated suction roll or a suction tube. The suction tube can suck either pulsed or continuously. The openings of the suction roll or the suction pipe can be shaped as desired, so that more complicated hole shapes, such as stars, alphanumeric characters, etc., can be generated.

In one variant, the fibers of the second paper web are only partially removed by the suction device in order to produce regions of lesser layer thickness in the second paper web. The regions of reduced layer thickness of the second paper web may, for example, be in register with watermark regions of the first paper web so as to make them bright.

According to another variant, the fibers of the second paper web are completely removed by the suction device in order to produce openings in the second paper web. These openings are advantageously produced in register with openings of the first paper web. The openings of the first and second paper web can thus complement each other to a see-through hole. Preferably, the openings of the first paper web are produced by so-called E-types on a round screen, while the opening in the second paper web is formed as a continuous strip with the continuously sucking suction tube and the E-type opening and strip opening come to lie one above the other. Of course, it is also possible to additionally arrange a strip-shaped security element between the paper webs or in one of the paper webs, wherein the security element lies in advantageous embodiments in the region of the openings. The width of the security element can correspond to the width of the openings, but also be smaller or larger.

In a particularly expedient embodiment of the method, the suction device is arranged between the second and the first wet end, so that it sucks the paper fibers of the second paper web on their way to the first paper web. However, it is also possible to arrange the suction device after the merging point of the first and second paper web. The paper fibers of the second paper web are in this case preferably sucked through openings in the first paper web.

In order to ensure the registration of the openings of the first and second paper web, it is advisable to produce the first paper web on a round screen, and to drive the suction device, in particular the perforated suction roll in register to this round screen.

Said register-containing openings of the two paper webs are advantageously combined with a security element whose respective security features are then visible from both sides of the security paper. As a security element is in particular a security thread, preferably a two-sided security thread, such as a double hologram security thread, a dual color layer security thread or the like into consideration. The security element can also have an element in the paper web running direction which is in register with the document to be produced. The security element is then introduced in the longitudinal register, which can be done for security threads, for example by means of a direct thread drive.

Especially in confined spaces between the first and second wet end, it may be appropriate to form the suction device in a trapezoidal or triangular shape in order to obtain a sufficiently large contact surface with the second paper web.

In a further advantageous embodiment of the method, a suction device is used, which is designed as a composite of several segment plates Absaugrad.

Such a suction device may generally be used in papermaking to create thin spots or openings in a wet paper web. The suction device is formed by a composite of several segment plates Absaugrad, wherein one or more intermediate plates are provided as a segment plates, which form the removal openings for sucking a substance / water mixture from the wet paper web, and two on both sides of the intermediate plates arranged cover plates, the edge boundary serve. At least a portion of the segment plates expediently has channels connected to the removal openings for the extraction of the substance / water mixture. In order to prevent the adhesion of fibers, the areas of the intermediate plates adjoining the removal openings are advantageously recessed.

In addition, a stationary vacuum device may be provided, which grinds in operation on the surface of at least one of the cover plates of the rotating Absaugrads and which is connected to the exhaustion of the substance / water mixture via one of the channels with each standing in contact with the paper web removal opening.

According to an advantageous development, the suction device is coated with a flexible plastic mask, which has recesses in the form of patterns, characters or codes in the region of the removal openings. These recesses can be made very fine and be formed, for example, in the form of alphanumeric characters or finely engraved graphic symbols. They can also form continuous or registered patterns.

In a method for producing a security paper, which itself is not part of the invention, it is provided that in a wet end of a paper machine on a round screen a paper web is formed and lifted by means of a carrier tape from the round screen, and in which the lifting of the paper web from a in Close proximity to the round screen and arranged with a short distance to the carrier tape suction device is supported. In the suction device, a negative pressure is preferably generated which is at least 0.1 bar, in particular by about 0.2 bar, greater than the negative pressure in the interior of the round screen. By means of such a suction device, the sheet formed can be particularly clean and detached without cracks from the round screen of the paper machine.

In an advantageous embodiment, the suction device is formed by a rotatable suction roll, which is preferably driven in register-synchronism with the round screen of the wet end. In an advantageous embodiment, the suction roll on a perforated roll shell, which is surrounded by a perforated blanket and a felt defined permeability.

The method described is particularly suitable for those production variants in which on the round screen a watermark in the paper web is introduced. Because of the different paper thickness, the distance of the suction device to the round screen is then adjusted appropriately in the region of the watermark to the local paper thickness.

In a papermaking screen in a paper machine, which itself is not part of the invention, it is provided that the screen has ridges and depressions for producing watermark areas, and structuring is provided in the pits to facilitate paper separation from the screen ,

In an advantageous variant, the elevations and depressions for generating Balkenwasserzeichen are arranged bar-shaped next to each other. The structurings are particularly advantageously formed by grooves, in particular by grooves milled into the recesses. The patterning in the recesses results in a more regular deposition of stock on the screen, an improved decrease and thus a more uniform brightness in the watermark areas of the produced paper web.

• eine erste Papierbahn gebildet und mit einer Öffnung versehen wird,
• eine zweite vollflächige Papierbahn gebildet wird, die im noch feuchten Zustand mit der ersten Papierbahn zusammengeführt wird,
• die zusammengeführte erste und zweite Papierbahn zwischen einem erst- und einem zweitbahnseitigen Trägerfilz geführt werden, und
• der zweitbahnseitige Trägerfilz von der zusammengeführten Papierbahn abgehoben wird, um im Bereich der Öffnung der ersten Papierbahn einen Teilbereich der zweiten Papierbahn mitzunehmen und dadurch eine Durchgangsöffnung in der zusammengeführten Papierbahn zu erzeugen.

The present invention relates to a method for producing a passage opening in a multi-layer security paper, in which

• a first paper web is formed and provided with an opening,
• a second full-surface paper web is formed, which is brought together in the still wet state with the first paper web,
• the merged first and second paper web are guided between a first and a second web-side carrier felt, and
• the second web-side carrier felt is lifted off the merged paper web in order to take along in the region of the opening of the first paper web a partial region of the second paper web and thereby to produce a passage opening in the merged paper web.

The second web-side carrier felt is expediently subjected to a suction pressure S ₂ and the first web-side carrier felt in the areas outside the opening with a suction pressure S _{1 is} applied, which is greater than S ₂ , so that the second paper web can not be lifted in these areas. In one embodiment of the method, no suction pressure is applied to the first web-side felt in the region of the opening, which can be achieved, for example, by pulsed suction. Advantageously, the first web-side carrier felt in the region of the opening even with a counter-blowing pressure, in particular an air jet, water jet or a laser beam, acted upon to support the lifting of the second paper web in this area.

In a multilayer security paper for the production of security or value documents, which itself is not part of the invention, a luminescent substance and optionally another feature substance are homogeneously distributed in the volume of the paper layer in at least a first paper layer of the security paper, said first paper layer at least in one Partial area has at least two different paper thicknesses.

Since the luminescent substance is homogeneously distributed in the paper, the different paper thickness is reflected in the amount of luminescent substance present or the luminescence radiation emitted, ie in areas with thicker paper, there is more luminescent per unit area than in areas with thinner paper, hence the intensity of the luminescent radiation is higher in areas with thicker paper than in areas with thinner paper.

If one now misses the intensity of the luminescence radiation as a function of the position of a sensor above the finished document, one can conclude on the thickness of the paper at this position and create a layer thickness profile of the paper. The particular advantage is that in papermaking a very specific thickness modulation, e.g. in the form of a barcode that can incorporate paper that can be easily measured using the procedure described. Only if the measured intensity curve corresponds to the incorporated thickness modulation is it a genuine document. Since a modification of the thickness modulation in papermaking is very easy, the security paper can be provided with a variety of different codes. The number of codes can be further enhanced by incorporating additional feature substances.

Suitable luminescent substances are all fluorescent and phosphorescent substances which emit light in the visible, UV and IR spectral range after appropriate excitation. Preferably, luminescent substances are used which emit outside the visible spectral range. For example, as luminescent substances can be used as in EP 0 053 183 Federation EP 0 052 624 B are disclosed.

The concentration of a luminescent substance based on the weight of the finished sized paper usually ranges from 0.05% by weight to 5% by weight, preferably from 0.1% by weight to 1% by weight.

The luminescent substance is preferably transparent in the visual spectral range, so that it is not readily visually recognizable. The range of available luminescent substances and their optically verifiable properties is very large, so that a potential fraudster, even if he knows that a luminescent substance is present, would have to carry out an elaborate analysis in order to check the correct luminescent substance as well as that from the competent authorities to find optical property of this substance. Luminescent substances which are not available in free trade and have special optical properties and are detectable only with special measuring devices tuned thereto are advantageously suitable for the machine inspection. For example, luminescent substances with anti-Stokes or quasi-resonant behavior can be used. Preferably, luminescent materials in which both excitation and emission spectrum are out of the visible range are used.

In the paper, the luminescent substances are incorporated by, for example, in papermaking e.g. the pulp are added and homogeneously distributed by stirring the paper pulp.

The luminescent substance used can be combined with one or more further luminescent substances but also with one or more further feature substances. In this case, all materials which can be incorporated into the pulp during papermaking and which can be recognized by machine, ie have a physically or chemically measurable or detectable effect, are suitable as feature substances. In this case, substances having electrical and / or magnetic properties are suitable, for example electrically conductive pigments, such as metal particles, electrically conductive polymers, magnetizable iron oxide or iron particles, paramagnetic particles, such as Ni or Mn. The concentration of a feature substance based on the weight of the finished sized paper is usually about 1 wt .-%.

The feature substances can be processed in papermaking, such as paper fillers. Processes for this are known to the person skilled in the art.

The first paper layer further has thickness modulations in at least a portion, i. Areas where the security paper has different thicknesses. Every conceivable form is possible. In the simplest case, an area with two different thicknesses is present in the paper layer. The different paper thicknesses can be produced by different techniques. In the paper layer and windows can be incorporated, so areas that have a paper thickness of zero.

Preferably, however, the thickness modulation is realized in the form of a watermark. The watermark can be incorporated during the scooping process in the paper layer or be subsequently embossed. The thickness modulation can have any conceivable shape. In the simplest form, the watermark represents a barcode. For example, the watermark can also be formed as a two-dimensional area code in the manner of a chessboard. But also complicated watermarks, z. As portraits, with many different paper thicknesses, which can be seen in the finished paper as different shades of gray, can be produced and used.

In the production of a bar code sign in the form of a bar code, one can understand the manufacturing process for security paper with window threads make use of, for example, in the EP 059056 A is described. This process is performed on a paper machine with a round screen. On a paper machine with a wire screen, on the other hand, the beam watermark is imprinted into the paper web via the dandy cutter after papermaking, resulting in the desired thickness modulations.

The paper of the first paper layer usually has a weight of 65 to 120 g / m ² , a density of 500 to 1000 kg / m ³ and a thickness of 50 to 200 microns. With an average paper thickness of 100 .mu.m, the thickness of the regions appearing brighter in transmitted light is about 85 .mu.m or less, and the thickness of the regions appearing darker in transmitted light is about 115 .mu.m or more.

The paper of the first paper layer preferably has a weight of 70 g / m ² , an average thickness of 100 μm and a density of 700 kg / m ³ . The light-emitting areas which appear brighter in this case have a thickness of about 70 μm.

In a further embodiment, the differences in thickness in the paper are visually imperceptible. This is achieved by keeping the thickness differences in the paper very small. The minimum or maximum paper thickness in the watermark is 1 to 10%, preferably 1 to 5%, below or above the average paper thickness. Paper thickness modulations, e.g. are in the range of 105 .mu.m to 115 .mu.m, are no longer visible in the transmitted light with the naked eye as watermarks, but with a sensor very well detectable.

Another possibility of camouflage is to overprint the areas of different paper thicknesses. Preferably, printing inks used, which in the spectral regions in which the feature substance is excited and emitted, do not absorb, ie are transparent.

In one embodiment of the multilayer security paper, the first layer comprises incorporated thickness modulations and at least one luminescent substance which can optionally be combined with further luminescent substances. The second layer may comprise no luminescent substance, the same luminescent substance as the first layer, a luminescent substance different from the first layer or else combinations of different luminescent substances. The same applies to any further existing paper layers. The paper thickness variations of the first and second layers or optionally also further layers can be coordinated so that the layers complement each other to form a multilayer security paper of constant thickness.

Optionally, one or more further feature substances can be incorporated independently of one another into the individual layers. The feature substances are, as described above, machine-readable substances, preferably with electrical and / or magnetic properties.

This aspect offers the advantage that, although it is merely provided with a luminescent substance, a security paper can be produced by simply varying the paper thickness with a variety of codes. By combining the luminescent and feature substances, the number of different possible variations can be further increased. The production of the coded security paper is particularly simple in that the incorporation of the luminescent and optionally feature substances as well as the paper thickness modulation in one step in papermaking and no additional equipment is required to be integrated into the paper machine. In this way, different currencies, denominations of a currency or even tax stamps, etc. can be cost-effectively provided with a machine-readable encoding.

In addition to the simple possibility of production, the counterfeit protection can be significantly increased by the fact that the coding is made invisible, i. Visually not recognizable, but nevertheless easily measurable by machine. Due to the integrated luminescence and feature substances in the paper volume, a subsequent change of the authenticity mark is not possible without destroying the paper.

Furthermore, a method for checking the authenticity of a security paper is described, which itself is not part of the invention. In this authenticity check, the luminescent, electrical and / or magnetic properties of the security paper are measured by means of a sensor, resulting in very specific signal intensities depending on the concentration of the luminescent or the feature substance and the paper thickness. The signal intensity is influenced as follows: the higher the concentration (amount of a substance per unit volume) of the luminescent or feature substance in the paper or the thicker the paper is at a certain point, the higher the intensity of the measurement signal.

In the case of a watermark, the paper appears thinner at the points appearing brighter in transmitted light, and thicker at the darker points in relation to the normal paper thickness. Consequently, the thickness modulation in the paper results in a modulation of the amount of luminescent substance. Accordingly, the signal intensity also varies. Advantageously, the Measurement by means of a hand sensor, which responds to the different luminescence or feature substances.

Some particularly advantageous embodiments of embodiments according to the invention will be explained below with reference to the figures, in the representation of which a representation true to scale and proportion has been omitted in order to increase the clarity.

Fig. 1

eine schematische Darstellung einer Doppelrundsieb-Papiermaschine zur Herstellung eines Sicherheitspapiers,

Fig. 2

eine Papiermaschine mit einer Rundsieb-Papiermaschine und einem Kurzformer in schematischer Darstellung,

Fig. 3

den Schichtaufbau eines Sicherheitspapiers nach einer illustrierenden Gestaltung im Querschnitt,

Fig. 4

in (a) den Schichtaufbau eines Sicherheitspapiers nach einer anderen illustrierenden Gestaltung im Querschnitt und in (b) und (c) eine Aufsicht auf die Vorder- bzw. Rückseite des Sicherheitspapiers,

Fig. 5 und 6

den Schichtaufbau weiterer Sicherheitspapiere im Querschnitt,

Fig. 7

in (a) ein Rundsieb eines Kurzformers mit aufgeklebtem Abdeckstreifen sowie in (b) einen Abschnitt des Abdeckstreifens selbst,

Fig. 8

ein Rundsieb wie in Fig. 7(a) mit einem im Inneren laufenden Abdeckring,

Fig. 9 und 10

den Schichtaufbau weiterer Sicherheitspapiere im Querschnitt,

Fig. 11

ein dreilagiges Sicherheitspapier, in (a) im Querschnitt und in (b) in Aufsicht,

Fig. 12

ein weiteres Sicherheitspapier in Aufsicht,

Fig. 13 und 14

den Schichtaufbau weiterer Sicherheitspapiere im Querschnitt,

Fig. 15

eine schematische Darstellung eines Doppelrundsiebsystems mit einer Lochblechwalze zur Herstellung von Sicherheitspapier,

Fig. 16

die Lochblechwalze der Fig. 15 separat,

Fig. 17 bis 20

den Schichtaufbau weiterer Sicherheitspapiere im Querschnitt,

Fig. 21 und 22

jeweils einen Teilbereich einer Papiermaschine zur Herstellung eines mehrlagigen Sicherheitspapiers,

Fig. 23

die Sauggautsche von Fig. 22 im Querschnitt,

Fig. 24

in (a) eine schematische Darstellung eines Siebs zur Herstellung von Balkenwasserzeichen und in (b) einen Querschnitt durch das vom Sieb abgelöste Papier im Wasserzeichenbereich,

Fig. 25

ein Zwischenstadium bei der Papierherstellung zur Illustration einer erfindungsgemäßen Möglichkeit, eine Durchgangsöffnung in einem mehrlagigen Sicherheitspapier zu erzeugen,

Fig. 26

ein Wertdokument aus Sicherheitspapier nach einer illustrierenden Gestaltung,

Fig. 27 bis 29

Varianten des Sicherheitspapiers der Fig. 26 bei einem Schnitt entlang der Linie A-A,

Fig. 30

ein Messsignal bei der Echtheitsprüfung, nämlich die Intensität I in Abhängigkeit vom Messort,

Fig. 31

eine schematische Darstellung einer Papiermaschine mit Absaugeinrichtungen,

Fig. 32

ein Sicherheitspapier, in (a) in Aufsicht und in (b) im Querschnitt,

Fig. 33 und 34

schematische Darstellungen von weiteren Sicherheitspapieren in Aufsicht,

Fig. 35

ein weiteres Sicherheitspapier im Querschnitt,

Fig. 36

eine in der Papiermaschine der Fig. 31 einsetzbare Absaugeinrichtung, die besonders für beengte Platzverhältnisse geeignet ist,

Fig. 37

einen Ausschnitt einer Seitenansicht eines Absaugrads nach einem weiteren Beispiel,

Fig. 38

eine Aufsicht auf ein Absaugrad mit gegenüber Fig. 37 etwas anders gestalteten Entnahmeöffnungen, und

Fig. 39

in (a) und (b) Seitenansichten der mittleren Segmente des Absaugrads von Fig. 38 in Blickrichtung der Linien A-A bzw. B-B.

Show it:

Fig. 1

a schematic representation of a Doppelrundsieb paper machine for producing a security paper,

Fig. 2

a paper machine with a rotary screen paper machine and a short shaper in a schematic representation,

Fig. 3

the layer structure of a security paper according to an illustrative design in cross-section,

Fig. 4

in (a) the layer structure of a security paper according to another illustrative embodiment in cross-section and in (b) and (c) a plan view of the front and back of the security paper, respectively;

FIGS. 5 and 6

the layer structure of further security papers in cross-section,

Fig. 7

in (a) a round sieve of a short shaper with glued-on cover strip and in (b) a section of the cover strip itself,

Fig. 8

a round screen like in Fig. 7 (a) with a cover ring running inside,

FIGS. 9 and 10

the layer structure of further security papers in cross-section,

Fig. 11

a three-ply security paper, in (a) in cross-section and in (b) in supervision,

Fig. 12

another security paper in supervision,

FIGS. 13 and 14

the layer structure of further security papers in cross-section,

Fig. 15

a schematic representation of a Doppelrundsiebsystems with a perforated plate roller for the production of security paper,

Fig. 16

the perforated plate roller of Fig. 15 separately,

Fig. 17 to 20

the layer structure of further security papers in cross-section,

FIGS. 21 and 22

in each case a subarea of a paper machine for producing a multilayer security paper,

Fig. 23

the suction cup of Fig. 22 in cross section,

Fig. 24

in (a) a schematic representation of a sieve for the production of Balkenwasserzeichen and in (b) a cross section through the screen peeled paper in the watermark area,

Fig. 25

an intermediate stage in papermaking for illustrating a possibility according to the invention for producing a passage opening in a multilayer security paper,

Fig. 26

a document of value made of security paper according to an illustrative design,

Fig. 27 to 29

Variants of the security paper of Fig. 26 at a section along the line AA,

Fig. 30

a measurement signal during the authenticity test, namely the intensity I as a function of the measuring location,

Fig. 31

a schematic representation of a paper machine with suction,

Fig. 32

a security paper, in (a) in plan view and in (b) in cross-section,

FIGS. 33 and 34

schematic representations of further security papers in supervision,

Fig. 35

another security paper in cross section,

Fig. 36

one in the paper machine the Fig. 31 usable suction device, which is particularly suitable for confined spaces,

Fig. 37

a section of a side view of a Absaugrads according to another example,

Fig. 38

a view of a Absaugrad with opposite Fig. 37 slightly different designed removal openings, and

Fig. 39

in (a) and (b) are side views of the central segments of the Absaugrads of Fig. 38 in the direction of the lines AA and BB.

Fig. 1 shows a schematic representation of a Doppelrundsieb-paper machine 10, as it is used in the manufacture of security paper. The paper machine 10 includes two rotary screen paper machines 12 and 14, which communicate with each other via a pick-up felt 16.

In the first paper machine 12, a paper web 20 is formed on a round screen 18, in which a security element, here a wide liquid-impermeable security tape 22, is embedded. For this purpose, the security belt 22 runs on bumps 26 of the round screen 18 before it dips into the paper pulp 24 of the paper machine. The security tape 22 may, for example have a width of 20 mm or even 30 mm. Due to its large width, no sheet formation takes place in the areas in which the liquid-impermeable security tape 22 rests on the protuberances 26 of the first paper wire 18, so that the security tape 22 divides the first paper web 20 into two parts. At the edges of the security band 22 forms a characteristic deckle edge. For better anchoring of the safety band 22 liquid or even fiber-permeable areas can be provided in its edge regions.

In the second paper machine 14, a second, homogeneous paper web 30 is produced in parallel thereto, removed from the round wire 34 by means of the pick-up felt 16 and guided to the first paper machine 12, where it is connected to the first paper web 20 in the region of the pressure roller 36. The first paper web 20 with the enclosed security tape 22 is covered over its entire area by the homogeneous second paper web 30. The interconnected paper webs 38 are then fed to other processing stations, such as calenders, sizing and the like.

The second paper web 30 may, as in Fig. 2 also be produced with a Kurzformer 40, in which the paper pulp is sprayed onto the surface of a round screen 44 with a headbox 42. With such a short shaper, it is possible to produce particularly thin paper layers, for example with a grammage of 15 to 25 g / m ² .

It is understood that three or more paper webs can be produced and combined in an analogous manner with the paper machines 12, 14, 40 shown.

A multi-ply security paper 50, like one of the paper machines of the Figures 1 or 2 can be made is in Fig. 3 shown in cross section. The security paper 50 includes a first paper ply 52 that is shared by a wide security tape 54 and a thinner second paper ply 56 that covers one side of the first paper ply 52. In an advantageous variant, the first paper layer 52 is provided with a watermark and the security tape 54 has a hologram or a hologram-like diffraction structure. The thin second paper layer 56 serves as a reinforcement in the region of the security band 54. Alternatively, in the first paper layer, there may be holes along the security thread embedded in the paper, which are wider than the security band. The second paper layer covers the first paper layer.

For the production of the multilayer security paper in Fig. 3 It is also possible to proceed in such a way that only paper layer 52 having a strip-shaped recess and paper layer 56 are produced and brought together, and then security tape 54 is inserted into the strip-shaped recess.

In the illustrative example of Fig. 4 an interruption 58 is introduced into the second paper layer 56, whose width or diameter 60 is smaller than the width 62 of the security band 54. The interruption 58 may be formed, for example, in the form of a strip-shaped opening with a width of 60, but also in the form of individual openings of any shape. The dimension 60 then corresponds to the extent of the openings perpendicular to the running direction of the safety belt 54. For an embodiment of the interruption 58 as a linear hole pattern shows Fig. 4 (a) the security paper in cross section and the FIGS. 4 (b) and 4 (c) Supervision on the front and back of the security paper.

The further illustrative example of Fig. 5 shows a security paper 64, in which, unlike the example of the Fig. 4 not a wide security band, but a narrow security thread 66 is embedded with a width of 1.5 mm or less. With such security threads, the back sheet formation in the first paper machine 12 is not suppressed, so that the security thread 66 does not divide the first paper layer 52, but is embedded in it and freely accessible only from one side.

In both variants, the first paper layer 52 may include a watermark, additional openings or other authenticity marks. Contains the first paper layer 52, as in Fig. 6 shown, a watermark 68, the second paper layer 56 is interrupted in the area of the watermark 68 with advantage to increase the visibility of the watermark. Of course, instead of the security thread, a wide security band in the security paper of the Fig. 6 be introduced.

In order to generate the interruption 58 in the second paper layer 56, the pores of the round screen of the second sheet forming unit, for example of the round screen 44 of the short former 40, are closed in partial areas. This can, as in Figs. 7 (a) and (b) shown by a glued to the jacket of the round screen 44 net strip 70 with covered in the form of the desired openings areas 72 done. The cover strip 70 may also be formed completely impermeable to produce a strip-shaped interruption.

Alternatively, the holes of the Sieboberfläche can be closed at the desired locations with a Lackaufdruck. A screen-applied paint layer can easily after job completion again be washed out and the screen for the next order with a new coat of paint are provided.

After the in Fig. 8 shown further variant, a running on the Siebachse 46 cover ring 74 is provided with closed and perforated portions in the interior of the round screen 44, which presses radially outward against the screen jacket and thus prevents sheet formation in the closed portions.

In all the described methods interruptions 58 are generated in the second paper layer 56, which have a non-adjustable by punching or cutting deckle edge.

According to a further variant of the manufacturing method, the security thread or the security tape runs on the second sheet forming unit, for example the short former 40. The round screen of the second sheet forming unit can be taped in the area of the security thread or safety bands or the incoming security element can cover the round screen itself accordingly. The thicker first paper web can be formed in this variant with or without a continuous opening in the region of the security element.

An example of a security paper 80 produced according to this production variant is shown in FIG Fig. 9 shown. The first and second paper layers 82 and 84 are shown for illustration only with different hatchings, they appear on the finished security paper 80 as a uniform paper layer in appearance. The security element 86 arranged in the gap of the second paper layer 84 is visible from both sides of the security paper through the interruption 88 in the first paper layer 82 and can be seen on both sides, for example Pages have optically variable elements. If necessary, the security element 86 may be secured with an adhesive in the gap of the second paper ply. The strip-like interruption or the other generated openings of any shape can be filled with polyurethane after drying the security paper.

A modification of the multilayer security paper of Fig. 9 , in which the interruption can be exposed at any time after manufacture, is in Fig. 10 shown. As in the example of Fig. 9 In the second paper layer 84 of the security paper, a security element 86 separating this paper layer and a strip-shaped interruption 88 in the first paper layer 82 are produced. In the strip-shaped interruption 88, a release strip 90 was additionally introduced in papermaking, on the back of which a thin paper layer 92 has formed. The release strip 90 may be peeled off the finished security paper together with the paper deposit 92 like a tearing thread and leaves a subsequently inserted opening in the first paper layer 82 which releases the view of the security element 86.

It is understood that more than two layers of paper can be combined into a multi-layer security paper. For example, a relatively thick paper layer formed on a DC round screen, into which watermarks, apertures or security element may be incorporated, may be combined with two or more thinner paper layers formed on further forming units, in particular the short formers described above. These paper layers can be produced with separate sheet forming units or even produced by separate headboxes on the same Kurzformer.

Some particularly advantageous illustrative examples of such multi-ply security papers will now be described with reference to FIGS FIGS. 11 to 14 described.

Figure 11 shows in (a) a three-ply security paper 100 in cross-section and in (b) in plan view. In a first, produced on a DC circular thick paper layer 102, a security strip or a wide security tape 104 is introduced in the manner described above. Two different colored thin paper layers 106 and 110 are applied to the first paper layer 102 using two short formers.

In the paper layers 106 and 110 strip-shaped interruptions are introduced by masking the round screens of the respective Kurzformer. The round screen of the first Kurzformers is provided with vertical adhesive strips to produce strip-shaped interruptions 108 in the second paper layer 106. The round screen of the second Kurzformers is taped with horizontal strips, whereby strip-shaped interruptions 112 are formed in the third paper layer 110, which are perpendicular to the strip 108 of the second paper layer 106. The designations "horizontal" and "vertical" for the adhesive strips refer to the axis of the respective short forming sieve.

By the mutually perpendicular interruption strips 108 and 112, a checkerboard-like pattern in the security paper 100 as well as views of the surface of the security element 104 in the crossing points. In the example, the second paper layer 106 is colored reddish, while the first and third paper layers 104 and 110 are white.

In regions 114 where neither the second nor the third paper layer is interrupted, the reddish coloration of the second paper layer 106 shines through the thin third paper layer 110 and produces a slightly reddish appearance. In the horizontal interruptions 112 of the third paper layer, the view of the second paper layer 106 is released, so that a more powerful red color appears there. At the points of interruption only in the second paper layer 106, the red color is absent so that these points produce a vertical white stripe pattern against a reddish background. Finally, in the crossing regions 116 of the two interruption patterns, the surface of the first paper layer 102 is exposed. In that interruption strip 108, which lies just above the security tape 104, the view of the surface of the security tape 104 is released in the crossing regions 118, so that further authenticity features can be recognizable there.

A security paper according to another variant is in Fig. 12 shown in supervision. In this variant, a first Kurzformer generates a paper layer 122 with strip-shaped interruptions and a second Kurzformer generates a complementary paper layer 124 also with strip-shaped interruptions, so that the two strip-shaped paper layers 122,124 complement each other to a full-surface paper layer 120. To produce a visually or machine-testable contrast, the paper layers 122, 124 are formed in particular from different fibers, for example from fibers of different colors, different lengths or from fibers with different feature additions. The paper layer 120 may also be combined with a third, homogeneous paper layer or with further layers of paper or plastic.

Another illustrative example is in Figure 13 shown. In order to combine a particularly high tear strength with a clearly recognizable and distinct watermark, the security paper 130 uses paper layers of different thicknesses and with different fiber lengths. The middle paper ply 132 is formed on a DC short fiber screen. This paper layer 132 occupies about 2/3 of the total thickness of the security paper 130. It is provided in a partial area with a watermark 134, which is sharply contoured due to the short fibers used and appears with a pronounced watermark effect.
On its top and bottom, the middle paper layer 132 is connected to two thinner paper layers 136, which are produced, for example, with a Kurzformer. For their production longer fibers are used, which give the multilayer structure 130 a particularly high tensile strength.

Another variant is in Fig. 14 shown. In this variant, a thicker paper layer 142 of the security paper 140 is provided with a watermark 144. On the surface of the first paper layer 142 two mutually complementary Kurzformerlagen 146 and 148 are applied, wherein the first Kurzformerlage 146 has a strip-shaped interruption in the region of the watermark 144, in which the second Kurzformerlage 148 comes to rest. The second short former layer 148 is formed with transparent fibers, in the example with suitable polymer fibers, by which the watermark region 144 is at the same time well protected and clearly visible.

Another way to produce security paper on a Doppelrundsiebsystem with high speeds, is now with reference to the FIGS. 15 to 20 explained. Fig. 15 schematically shows a similar to in Fig.1 constructed Doppelrundsiebsystem 150 with a first round screen 152 and a second round screen 154 for producing a first and second Paper web 156 and 158, which are brought together and connected to each other in the region of the pressure roller 160. The first-round sieve 152 is usually designed individually for the production of various security papers.

If the second paper web 158 is in the grammage range of approximately 10 to 45 g / m ² , then it has proven to be particularly effective if the second paper web 158 is produced homogeneously, that is to say with velin character, since then the second round sieve 154 can be made homogeneous , In particular, in this case eliminates the need to adjust the second round sieve 154 respectively to the individual design of the first round sieve 152. This makes it possible to optimize the technical structure to a stable and maintenance-free production of just this Velinpapiers low grammage. A project-individual design of Zweitrundsiebs 154 is then only with considerable effort or not possible.

In some cases, however, an individualization of the second paper web is desired. If, for example, an opening of the paper to the second round sieve side takes place in addition to an opening of the first-round sieve side and this opening takes place in the wet end, in general the second round sieve 154 must be individualized. Earlier, possibilities were already given to achieve this individualization by partially closing the holes of the second round screen. These options are particularly useful when the Zweitrundsieböffnung in paper web running direction without any registration can be placed differently on each document produced.

If, on the other hand, the second round sieve opening is to be located at specific, predetermined locations of the documents produced, then the above-described Procedure the circumference of the second round screen to be adapted to the first round screen and operated in register and speed of rotation to match the first round screen. This brings a considerable effort in the establishment of paper machines as well as the Siebherstellung and the screen change with it.

The manufacturing route described below is therefore based on the idea of leaving the most efficient mode of operation of the second round screen in the grammage range of 10 to 45 g / m ² and of achieving individualization not via individualization of the second round screen 154 but via individualization of the produced vellum paper web 158 , For this purpose, a perforated plate roller 170 is provided in the embodiment, the in Fig. 16 again shown separately.

The perforated plate roller 170 has a sheet-metal drum 172 in paper web width, which has holes 174 in a desired arrangement and size and which is further provided with a vacuum suction port 176. The perforated plate roller 170 is rotatably mounted and arranged between the second round screen 154 and the first round screen 152 at a small distance from the pick-up felt, on which the second paper web 158 is guided to the pressure roller 160. The circumference of the plate drum 172 corresponds to the length of a printing sheet and is thus in register with the first-round sieve 152. In addition, the perforated plate roller 170 is driven in register with the first-round sieve 152 in order to maintain the registration.

Paper fibers can be sucked out of the second paper web 158 via the vacuum suction connection 176 and the bores 174 so that new effects in the register for the first paper web 154 can be achieved.

For example, the example of the Fig. 17 a security paper 180 having a first paper layer 182 with a watermark 184 and a second paper layer 186 applied to the first paper layer. With the perforated plate roller 170, paper fibers were removed in the wet end of the paper machine 150 from the second paper layer 186 in register with the watermark 184 that the watermark 184 is clearly visible. For this bright position of the watermark 184, it is not necessary to remove all paper fibers in the watermark area, but it is sufficient a partial suction of fibers from the second paper web 156, as in Fig. 17 shown.

A punctual complete removal of the fibers of the second paper layer 186 comes into consideration, as with the security paper 190 of Fig. 18 shown. In the extracted areas 188, the first paper layer 182 is completely exposed.

The partial or complete removal of the paper fibers of the second paper web can be combined, in particular together with openings of the first paper web, with the introduction of various security elements, such as pendulum security threads, two-sided security threads or side-by-side two-sided security elements. The security element can have an element in the paper web running direction which is in register with the document to be produced. The security element is then introduced in the longitudinal register, which can be realized for security threads, for example with a direct thread drive.

Fig. 19 shows a security paper 200 having a plurality of see-through openings 202, which are formed by register openings arranged in the first and second paper layers 204 and 206, respectively. The see-through openings 202 For example, after paper making, one or both sides may be closed with a transparent or translucent film 208.

In the modification of the Fig. 20 When the first paper web is produced, the two-sided security thread 212 is inserted so that it lies completely on the first felt side. The see-through opening 214 formed by the register-containing openings of the first and second paper layers is then closed by the security thread 212 from the inside when the perforated plate roller 170 is operated accordingly. From the two opposite sides of the security paper 210 then each of the top and bottom security features of the security thread 212 can be seen.

The inspection opening (s) of the Figures 19 or 20 can also be designed with a foil thread element, which is inserted in the correct side and / or stands in the longitudinal register for the document to be produced.

The perforated plate roller can also be arranged only after the merger point of the first and second paper web and there suck the paper fibers of the second, thinner web through openings of the first paper web.

Especially in the production of relatively thin paper webs, as they are often used for one of the paper layers of a multilayer security paper, there is a risk that holes are torn in the finished paper web when detaching the web from the round screen. Remedy can be created here, for example, by a suction grille arranged above the carrier screen.

Fig. 21 shows for this purpose a portion of a paper machine for producing multi-layer security paper, such as in Fig. 2 illustrated paper machine. It is in addition to those already associated with Fig. 2 described elements arranged a suction cup 220 above the support 48 to lift the sheet formed clean from the round screen 44. The suction cup 220 generates for this purpose a negative pressure, which in the example by 0.2 bar is greater than the negative pressure in the interior of the round screen 44. The sheet is thereby pulled upwards by the suction cup 220 onto the carrier screen 48 and detached from the round screen 44 cleanly and without cracks.

Such a suction cup can advantageously also be used in conjunction with a DC round screen, as described in connection with FIG Fig. 22 illustrated.
Fig. 22 shows a portion of a paper machine for producing multi-layer security paper, in which over the round screen 18, a suction cup 230 is arranged floating with a small distance. The floating arrangement protects the round screen 18 and the watermark types. Since the suction cup 230 is not seated on the round screen, it must be additionally driven by its own drive, with a register-synchronism with the round screen 18 is advantageous.

The distance of the suction cup 230 to the round screen is preferably less than 1 mm at a paper thickness of about 0.7 mm. The Gautsche 230 is therefore raised in watermark areas of the paper in which the paper thickness can be up to 1.2 mm, so that it does not touch the screen in these areas. Such a suction cup 230 can be advantageously used, for example, in the production of watermarked watermark in security paper. By supporting the separation of the paper web, beams with high brightness constancy are achieved.

In the example, the suction cup 230 includes, as in the cross section of Fig. 23 represented a perforated bronze jacket 232 of a thickness of about 2 cm. The openings 234 in the bronze shell have a diameter of about 6 mm. On its outside, the bronze shell 232 is surrounded by a perforated blanket 236 and a felt 238 of defined permeability.

The uniformity of the watermark in a multi-ply security paper can also be determined using the in Fig. 24 (a) better showed 240 sieves. The screen 240 has a correspondingly arranged sequence of elevations 242 and depressions 244 for generating a bar water mark. In the recesses 244 of the screen, so the locations of greater paper thickness, grooves 246 are milled, which facilitate the paper removal from the screen 240. It has been found that the grooves 244 result in a more regular deposit of pulp on the wire, an improved decrease and thus a more uniform brightness of the generated watermarks in the raised paper web 248 (FIG. Fig. 24 (b) ) to lead.

As already mentioned above, it may be desirable to form a through opening in a multilayer security paper. For this purpose, register-containing openings in the paper layers can be produced, for example, by means of the above-described perforated plate roller. A method according to the invention for producing a passage opening in a multilayer security paper will now be described with reference to the illustration of FIG Fig. 25 explained.

Fig. 25 shows an intermediate stage in papermaking in which a first and second paper web 250 and 252 are already merged and bonded together. In the first, thicker paper web 250 is an opening 254 introduced, the second paper web 252 is formed homogeneously and without individualization. The two paper webs 250, 252 run on a first felt 256, which is acted upon in the regions 258 outside the opening 254 with a suction pressure S ₁ . At a second, on the second paper web 252 resting felt 260 is a suction pressure S ₂ upwards. The suction pressure S ₁ is greater than the suction pressure S ₂ , so that the second paper web 252 in the areas 258 can not be lifted off the second felt 260.

In the region of the opening 254, for example by pulsed suction, no suction pressure S ₁ is applied downward. There, therefore, the suction pressure S ₂ prevails and the second paper web 252 is lifted off with the felt, so that a passage opening in the multilayer security paper 250, 252 is formed. Optionally, in the region of the opening 254, an air jet may also blow against the first felt 256 to facilitate lifting of the second paper web. Other measures, such as a generated by a laser beam or a water jet back pressure or special geometric hole shapes that facilitate the removal of the second paper web in the opening portion 254 may be provided.

As already mentioned, another possibility is to integrate authenticity features in multilayer security paper in the addition of feature substances, such as luminescent substances. Embodiments have been found to be particularly advantageous in which a luminescent substance is homogeneously distributed in the volume of the paper layer in at least one of the paper layers and this paper layer has different paper thicknesses at least in a partial region, as illustrated below by some exemplary embodiments.

Fig. 26 shows a value document 300, here a banknote, in which a bar watermark 302 is incorporated in the form of a bar code. Fig. 27 shows the value document 300 in section along the line A - A and reflects the layer structure of the security paper used. The security paper accordingly has a homogeneous first paper layer 304 and a second paper layer 306 connected thereto with a stepped profile.

The ridges 308 of the second paper layer, i. the thicker paper areas appear darker in transmitted light, the pits 310, i. the areas with thinner paper appear brighter in transmitted light. As a feature substance, a luminescent substance 312 is homogeneously distributed in the second paper layer 306.

This variant of the security paper can be produced by different methods. On the one hand, a barcode can be embossed into the second paper web, into which the luminescent substance has been homogeneously incorporated, and, on the other hand, a watermark in the form of a barcode can be introduced into the second paper web on the round screen during paper web formation. Of course, combinations of luminescent substances can also be used. Furthermore, a feature substance or else a combination of feature substances of the abovementioned type can be introduced into the second paper web.

Fig. 28 shows the structure of a value document according to another illustrative example in cross section. The value document 320 shows the same appearance as the one in FIG Fig. 26 illustrated value document, however, the second paper layer 306 here through openings 322 and the first paper layer also contains a luminescent substance 324, which may be different in particular from the luminescent substance 312. The first and / or second paper layer may also comprise one or more further feature substances of the type described above. For example, the first layer may contain a luminescent substance and the second layer may contain a feature substance.

The preparation of this variant can be carried out according to the production of security paper with window threads, as stated above. According to this principle, two sheets, an upper and a lower sheet are formed and joined together, wherein in the upper sheet windows are inserted and the lower sheet is made over the entire surface. In the production of upper and lower sheets, the desired luminescent and feature substances are incorporated into the sheets. Alternatively, the windows in the top sheet can be produced even after its production by punching, cutting or the like.

Fig. 29 shows a two-layered structure of a value document 330, as it is in a section along AA in Fig. 26 results. In this example, both paper layers have bar watermark. The second paper layer 306 contains a luminescent substance 312, the first paper layer 304 contains one of 312 different luminescent substance 324 and, moreover, a feature substance 332. It is also possible for further luminescent substances to be present independently of one another in the first and / or second layer and optionally independently one or more feature substances are incorporated into each other in the first and / or second position. In general, the bars of the different layers can be congruent or even aligned with gaps. In a further embodiment, the thickness modulations in both layers can be realized by means of windows.

Fig. 30 shows a measurement signal 340, as it results in the authenticity check of a value document 300 with bar watermark 302. The intensities I of the measuring signal 340 are plotted on the ordinate as a function of the measuring position x, ie the position of the sensor above the document of value. The emission intensity of the luminescent substance 312 is measured here. In areas with thicker paper, the signal intensity is greater than in areas with thinner paper, since more or less luminescent or feature substance is located under the sensor as a function of the paper layer thickness. If the sensor is moved across the bar watermark 302, a higher intensity is measured in the region of the thicker paper than in the area of the thinner paper, and thus a type of barcode is measured, which is represented by the measurement signal 340.

If the value document or the layer to be tested of the value document has windows without luminescent substance 312, the measured intensity of the luminescent substance drops to zero. The authenticity check for value documents 320 or 330 with different luminescent substances takes place analogously, whereby if appropriate filters are used which only let through the radiation of one of the luminescent substances.

Further illustrative embodiments will now be described with reference to FIGS FIGS. 31 to 39 explained. First, the example shows the Fig. 31 a paper machine 370 in which a first paper layer with a countercurrent rotary screen 374 and a second paper layer with a short former 372 is produced. Although reference is always made below to the first paper layer as Gegenstromrundsieblage, it is understood that the first paper layer can be produced in other configurations with a DC strainer.

The two paper layers are brought together in the area of the take-off roll 376 and chatted with each other. Between the paper layers, a security thread 378 or a security tape supplied to the countercurrent rotary screen 374 is introduced. Openings can be introduced into the second paper layer (short former layer) 384 by means of a first suction device 380 arranged between the short former 372 and the countercurrent circular sieve 374. If desired, by means of an optional second suction device 382, which is arranged after the merging point of the two paper layers, also openings in the first paper layer (Gegenstromrundsieblage) can be introduced.

Fig. 32 shows a section of a two-ply security paper 350 in supervision, as with a paper machine 370 of in Fig. 31 shown type can be produced. In the first paper web 360 is a circular hole 354, which was preferably produced paper-making by applied to a round screen E-types. In the second paper layer 358, which was preferably produced by means of a Kurzformers, there are star-shaped openings 356. These openings were generated in the embodiment by means of a perforated suction roll 380, which removed the paper fibers from this second paper web while still wet. The shapes of the two openings 354 and 356 can be configured as desired. The position of the openings to each other and their size can be controlled according to the requirements. For example, the two openings can come to lie one above the other so that a see-through window is created. Of course, they can also be arranged side by side. Of course, the openings may be larger or smaller or equal in size relative to each other. In addition, as shown in this embodiment, in the region of the openings, a band-shaped security element 352, for example a wide security thread, between be embedded in the paper webs. The band-shaped security element 352 is covered by the first and second paper layers and is visible only in a plan view of the openings 354 and 356. Fig. 32 (b) shows the cross section of the security paper along the line A - A. The band-shaped security element 352 is covered by the second paper layer 358 and the first paper layer 360 and is accessible at the openings 354 and 356. The size of the openings can correspond to the width of the security band. But it is also quite possible that one or both openings is wider or narrower than the band-shaped security element is / are.

If the two paper layers are a short-former layer 358 and a countercurrent circular layer 360, between which a security thread 352 is embedded, then the different relative sizes of the openings in the short-form layer and the countercurrent circular layer, the width of the security thread 352 and the relative arrangement of the Both openings and possible features of the security thread a variety of possible designs, all with the paper machine 370 of Fig. 31 can be produced (or in other embodiments, with a paper machine in which the first paper layer is generated by a DC strainer).

In a first variant, openings 356 are generated in the short former position by the first suction device 380, which can represent any desired shapes, for example also characters, symbols or the like. On Gegenstromrundsieb 374 a thread 352 is introduced, which rests on an E-type. The E-Type is chosen so high that fibers can "float" under the introduced thread and thus the thread is in the range of E types open. The Gegenstromrundsieböffnungen 354 are always narrower than the thread width formed in this variant. The forms of Short form ply opening 356 may be narrower than the thread width, as in FIG Fig. 32 (a) shown, or even wider. The orifices 356 may be aligned in positional accuracy with the countercurrent vents 354, as in FIG Fig. 32 (a) shown on the left or coincidentally between these openings or overlap with them. In the first case, this variant shows a see-through window, the size of which is limited by the openings 354 in the counter-current round sieve layer, see Fig. 32 (b) , The desired shape 356 can be seen only in the incident light from the side of the short-form position. In the second case, this variant provides a substrate in which the introduced security thread 352 is partially open on both sides. A see-through window is then formed only when opposing openings overlap randomly.

In a second variant, the in Fig. 33 shown in plan view, the openings 354 are always formed in the Gegenstromrundsieblage greater than the openings 356 in the Kurzformerlage, the openings 354 may be narrower or wider than the thread width. The short form liner openings 356 may be as in FIG Fig. 33 be positioned accurately to the openings 354 or lie randomly between these openings or overlap with them. A see-through window results only in positionally accurate alignment of the two openings. In this case, the shape of the shaper openings 356 is visible from both sides of the substrate. If the openings are not aligned with positional accuracy, a substrate with a security thread 352 partially exposed on both sides results again.

At a third, in Fig. 34 illustrated variant openings 356 are introduced into the Kurzformerlage as described above, while the Gegenstromrundsieb has neither E types nor an embossing. By register control, for example, by means of register marks 362 done can, the openings 356 are aligned in the Kurzformerlage on certain locations of the Gegenstromrundsieb supplied security thread 352. For example, a negative writing 364 of the security thread 352 can be seen in the openings 356 of the short former layer.

After a fourth variant, the in Fig. 35 shown in cross-section, 358 openings 356 are introduced into the Kurzformerlage and fed a security thread 352 on Gegenstromrundsieb. The countercurrent rotary screen 374 is provided with an embossing, the webs of which are preferably in register with the short former position openings 356, so that the generated window openings 354 in the countercurrent circular layer 360 and the openings 356 in the short former position 358 alternate on both substrate sides.

According to a fifth variant, an opening is first introduced into the short-former layer in the manner described and the short-former layer and the countercurrent circular layer layer are covered with the security thread. After the removal of the entire paper layer, an opening is sucked out through a second suction device 382 in the region of the security thread. The openings of the two paper layers can be in register with each other or arranged randomly.

The sixth variant is similar to the third variant, however, the Gegenstromrundsieb is provided in this variant with a watermark embossing, which falls on the region of the incoming thread. With the first suction device 380 openings of any shape are sucked out of the Kurzformerlage, so that the thread is exposed in the extracted areas. By registering watermarks and short former apertures, it can be achieved, for example, that the watermarks of the countercurrent circular sieve layer lie around the sucked-out openings.

Instead of sucking out molds from the first or second paper web, it is also possible to invert the suction mechanism of the first and / or second device 380, 382 and apply material to the paper layer. For example, any shaped openings of the device 380 may be filled with a material, such as fibers, plastic granules or rubber, and the material may be transferred to the wet short-form web by over-pressure or adhesion. Subsequently, the paper web is vergautscht with the Gegenstromrundsieblage with thread. The introduced material then appears in transmitted light as a dark shape. If an oil is applied as a material, the mold may also appear semitransparent in the dried substrate.

The diameter of the first or second suction device 380, 382 is dependent on the arc length and is suitably chosen as large as possible in order to keep the rotational speed as low as possible. However, the maximum possible diameter is also limited by the space between Kurzformer 372 and Gegenstromrundsieb 374. Since at a small diameter, the contact surface to the Kurzformerlage 384 will also be small, it may be advisable, especially in confined spaces, not to make the suction 380 round, but form in trapezoidal or triangular shape, as in Fig. 36 shown. In this embodiment of the suction device 380 Absaugformen 386 are mounted on a flexible base material 388. The drive takes place in the embodiment via a chain 390th

Particularly expedient embodiments of a suction device 380 will now be described with reference to the FIGS. 37 to 39 described. The embodiments shown there represent a Absaugrad 380, which consists of several segments 400 to 406 is composed. Fig. 37 shows a section of a Absaugrads 380 in side view, Fig. 38 a similar Absaugrad 380 with a slightly different design of the removal openings 408 and channels 414 in the region of such an opening in supervision and the FIGS. 39 (a) and (b) Side views of the middle segments 402 and 404 of FIG Fig. 38 in the direction of the lines AA and BB of Fig. 38 , In this case, the locations marked with the reference symbols 416 and 418 denote those in the cross-sectional views of FIG Fig. 39 (a) or (b) visible edges. In the Fig. 37 Side view shown corresponds to the side view of the cover plate 406 in the direction of the line CC of Fig. 38 ,

The Absaugrad 380 has a sandwich construction of a plurality of segment plates, through which a variety of shapes for the removal openings 408 can be achieved. In the embodiment, the Absaugrad consists of a first cover plate 400, two intermediate plates 402 and 404, and another cover plate 406. The plates 400 to 406 may be made of metal or an impact resistant, not too brittle plastic and using a laser beam, a water jet or the like Be made technology. The plates are screwed, with the seal optionally a Sprühdichtmasse and / or sealing rings are used. The circumference of the Absaugrads 380 corresponds to the arc length of the paper layer to be processed in the wet state. After screwing the Absaugrad 380 is inserted and fixed to a guide shaft, not shown. If necessary, several suction wheels can be pushed and fixed on the guide shaft. The guide shaft is driven centrally and in preferred embodiments runs synchronously with the web speed.

After the start of the paper machine and the Absaugrad 380 starts, is brought to production speed and the Kurzformerbahn 384 delivered until form through the suction openings in the Kurzformerbahn. In the Fig. 37 and Fig. 39 (a) identifiable raised areas 410 pierce the still wet paper web and an opening of the desired shape is sucked off by an applied partial vacuum via the removal opening 408. In order to prevent the adhesion of fibers on the surface of the suction wheel 380, the areas adjacent to the removal openings 408 may be recessed.

The extraction of the substance / water mixture via the removal opening 408 and a channel 414 which extends through the intermediate plate 404 to the cover plate 406. In order to safely remove the extracted substance, the removal openings 408 and the channels 414 must be cleaned. For this purpose, for example, a trough 392 with filtered water ( Fig. 31 ), which passes through the suction wheel 380 in the opposite region of the suction. The vacuum is in the embodiment with a fixed vacuum device 394 ( Fig. 31 ), which grinds on the surface of the cover plate 406. The suction thus acts via one of the channels 414 only at the removal opening 408 which is in contact with the paper web 384.

How best in Fig. 38 To recognize the sandwich construction of several segment plates allows an almost unlimited shape for the removal openings 408. The intermediate plates, which can be put together in any number, thereby generating the shape of the removal openings per se. By the number and thickness of the intermediate plates, the width of the opening can be adjusted. For example, a 10 mm wide opening by two intermediate plates ä 5 mm, or by five intermediate plates ä 2 mm are produced. The cover plates 400, 406 serve to limit the boundary and the application of the vacuum. While in Fig. 38 just a cover plate 406 has a channel opening, such openings may of course also be provided in both cover plates, in which case on both sides of Absaugrads 380, a vacuum device 394 would be arranged.

It is understood that the described design can also be used for the second suction device 382.

The suction devices 380 and 382 may also be coated with a flexible plastic mask in which not only comparatively coarse but also very fine patterns, such as alphanumeric or abstract characters, may be recessed. In this way, continuous patterns, such as meander shapes or continuous texts, or even accurately arranged patterns, such as value specifications in a banknote, can be generated in the paper layers. The mentioned patterns can be arranged in one of the paper layers or congruent or offset in both paper layers.

Claims (5)

1. A method for producing a through opening in a multi-ply security paper, wherein

   - a first paper web (250) is formed and provided with an opening (254),

   - a second contiguous paper web (252) is formed that, still in the wet state, is merged with the first paper web (250),

   characterized in that

   - the merged first and second paper web (250, 252) are guided between a first- and a second-web-side carrier felt (256, 260), and

   - the second-web-side carrier felt (260) is lifted up from the merged paper web (250,252) to pick up a sub-area of the second paper web in the region of the opening (254) of the first paper web (250) and, in this way, to produce a through opening in the merged paper web (250, 252).
2. The method according to claim 1, characterized in that the second-web-side carrier felt (260) is acted on with a suction pressure S₂, and the first-web-side carrier felt (256) is acted on in the regions (258) outside the opening (254) with a suction pressure S₁ that is greater than S₂.
3. The method according to claim 1 or 2, characterized in that the first-web-side carrier felt (256) is not acted on in the region of the opening (254) with a suction pressure.
4. The method according to claim 3, characterized in that the first-web-side carrier felt (256) is not acted on in the region of the opening (254) with a suction pressure by pulsed suction.
5. The method according to claim 1 or 2, characterized in that the first-web-side carrier felt (256) is acted on in the region of the opening (254) with a counter blowing pressure, especially an air jet, water jet or a laser beam.

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