RU2774535C2 - Method for surface application of protective device above perforation made by paper-making machine - Google Patents

Abstract

FIELD: paper industry.

SUBSTANCE: group of inventions relates to sheet material containing a protective device, to a protected or valuable document containing fibrous sheet material, to a method for the surface application of a protective device, as well as to fibrous sheet material prepared in accordance with such a method. In this case, sheet material (110) has opposite surfaces, a recess in one opposite surface and one or more through perforations (111) that pass from the recess through another opposite surface of fibrous sheet material, wherein one or more through perforations are through perforations formed during the manufacture of paper, wherein fibers pass in one or more holes bounded by the mentioned one or more through perforations, wherein sheet material contains fibrous subdomain (114), which is located below the recess and which surrounds the mentioned one or more through perforations, and an adjacent area of the main mass located next to the mentioned recess and fibrous subdomain; protective device (112) of surface application, located in the recess above the mentioned one or more through perforations; and interface zone (117) between the protective device of surface application and the fibrous subdomain and the area of the main mass. By means of the method for the present invention, a through perforation is performed in the formed fibrous canvas before it becomes sufficiently compacted, and then, the protective device is applied to the fibrous canvas. The application of the protective device and then additional compaction of the area under the device at this stage of paper making, when fibers cannot be displaced, significantly reduces the probability of that the through perforation will be closed or blocked.

EFFECT: documents manufactured in accordance with the method for the present invention, when conducting a test for imitation of circulation, demonstrate minimal damage in an interface zone of paper with a protective device; in addition, protective devices of surface application demonstrated acceptable levels of ink adhesion during gravure printing, and paper had a higher tensile strength in the transverse direction and much less translucency on their opposite sides.

20 cl, 18 dwg

Description

FIELD OF TECHNOLOGY

[0001] In one aspect, the present invention relates to a sheet material having through perforations with one or more security devices connected to the through perforations. Exemplary sheet materials are used to make security documents that contain the aforementioned through-perforations and are bonded by a security device. In another aspect, the present invention also generally relates to a method for producing such sheet material; a method of manufacturing such sheet material; and means of protecting these documents by connecting through perforations to the security device(s). The through perforations described herein include "soft edge" through perforations. Accordingly, a further aspect of the present invention also includes methods for forming through-perforations in a sheet material with soft edges, or more particularly in a security document.

BACKGROUND OF THE INVENTION

[0002] Security devices, which non-exclusively include various kinds of strips, strips, threads or tapes, are widely used to provide security or aesthetics to high security and high value documents by providing a visually and/or machine detectable means for verification of the authenticity of these documents. These security devices may be either fully recessed or partially recessed into or attached to the surface of the documents.

[0003] Security devices that are at least partially buried can be applied to the fibrous web being formed by introducing the security device into the fibrous web during the wet stage of the papermaking process. However, incorporating security devices into the fibrous web at this stage, while at the same time suitable for embedded and partially embedded security devices, has hitherto been impractical for surface applied security devices because the resulting sheet or document would be subject to reduced wear resistance (e.g. , wear resistance during handling).

[0004] It has been found that during wet stage insertion of the protector onto the fibrous web being formed, some of the fibers are displaced as they flow around the protector as it is pressed into the fibrous web. This results in some fibers being displaced from the sub-region (i.e., the area of the fibrous web located under or below the security device) and the kinkline regions (i.e., the regions of the fibrous web located near the edges or sides of the security device), which is enough to influence the interaction of the security device with the fibrous web or with the substrate of the resulting sheet material or document. The resulting fiber concentration in the subregion and breakline regions is less than the fiber concentration in at least the adjacent bulk mass region(s). This results in weak bonding engagement at the interface between the security device and the substrate of the sheet material or document, and in particular results in weak bonding engagement at the adjacent surface and/or at the edges of the security device. During use or handling of the resulting documents, these weak areas are highly susceptible to tears in the sheeting or documents along adjacent edges between the security device and the substrate, or cause breakline effects (i.e., split areas between adjacent edges). In addition, there is a tendency for the reverse side of the document to show through; that is, the applied security device, when applied to one side of the fibrous web, will cause a shadow effect that is observed from the opposite side of the fibrous web, any resulting sheet material, or any resulting document. To solve this problem, the use of a camouflage coating on the reverse side is often required. It was also found that the specified resulting sheet material or document shows a decrease in tensile strength in the transverse direction (CD, cross-direction).

[0005] One alternative for obtaining a surface application security device is to apply a security device to the surface of a fully formed fibrous substrate. However, application to a fully formed fibrous substrate comes with other significant limitations. For example, this substantially limits the thickness range of the guard that can be used. In general, application to the surface is limited to the thinnest of the protective devices, for example, less than 15 micrometers (µm). Thicker guards are generally excluded from such applications, at least in part, because the resulting variation in sheet thickness of the resulting sheet material affects subsequent processing. As used herein, the term "sheet thickness difference" refers to the height difference measured from the top surface of the bulk sheet material region to the top surface of the security device. For this reason, the difference in sheet thickness can be negative or positive. For example, in cases where the top surface of the protector remains below the height of the top surface of the bulk sheet material region, the sheet thickness differential will be negative. On the other hand, in cases where the top surface of the protector remains higher than the height of the top surface of the bulk sheet material region, the thickness difference of the sheet will be positive. Alternatively, a zero sheet thickness difference indicates that the top surface of the guard is flush with the top surface of the bulk region. Due to the difference in sheet thickness obtained with thicker guards, which are introduced either during the dry stage of the papermaking process or during the post-application process, to subsequent processes such as winding, sheeting, stacking, cutting and processing ATM has an impact in terms of time and cost. It is important to note that the stacks thus obtained are not ready for pressing or are not ready for printing.

[0006] In view of the foregoing, there remains a need to improve surface applied sheet materials, regardless of thickness, and to improve the processes by which these sheet materials are manufactured. There is also a continuing need to provide additional elements of authenticity for secure documents that provide the authenticity of the documents to be verified while serving to prevent unauthorized copying.

SUMMARY OF THE INVENTION

[0007] The present invention satisfies at least one of the above needs by providing a sheet material, a security document, and a method for surface-applying a security device to a fibrous sheet material or document by injecting a security device onto a fibrous web being formed during a wet papermaking step. In one embodiment, the security device is applied over one or more "soft edge" through perforations made in the fibrous web. The security device in this embodiment is made from a structural film and is at least about 10 micrometers thick, thus providing a device with sufficient wear resistance to cover the through-perforation(s). The term “soft-edge” through-perforation as used herein means a through-perforation obtained during paper manufacture, with the fibers of the sheet material passing into the hole defined by the through-perforation. The through-perforation opening extends from one side of the web surface to the opposite side or surface and exhibits characteristic irregularities in the edge region. Characteristic irregularities are formed as a result of the absence of a well-defined edge and contain non-uniform compactions of fibers in the edge region and/or fibers that pass into the hole. Where such through holes have characteristic irregularities that often vary and are difficult to repeat, these holes function as elements of authenticity with a high degree of security. The method of the present invention includes: introducing a security device onto or into the fibrous web being formed, optionally over one or more "soft edge" perforations formed therein, during the wet stage of the papermaking process at which the fibrous web is sufficiently densified. In one embodiment, the fibrous web is sufficiently densified when the fibrous web has a water or moisture content of less than 98% by weight, based on the total weight of the fibrous web. Preferably, the fibrous web is sufficiently densified when the fibrous web is on or near a couch roll or similar paper machine tool.

[0008] The present invention also provides a fibrous sheet material obtained by the above method, and the resulting document containing the fibrous sheet material. In a first embodiment, the fibrous sheet material has opposing surfaces, at least one recess on one surface thereof, a fibrous sub-region which is a three-dimensional space located under or below the recess, and a fibrous bulk region which is also a three-dimensional space located next to the recess and sub-region; a surface application protective device disposed in the recess; and an interfacing zone between the surface application protective device and the base mass region and the sub-region of the sheet material; moreover, in the fibrous sub-region and in the fibrous region of the bulk are fibers that are present in essentially the same amounts. The fibrous sub-region has the same extent in the transverse or lateral direction with the protective surface application device. In other words, the three-dimensional sub-region occupies the volume of the fibrous sheet material located under the security device. The fibrous region of the bulk is located adjacent to the recess and the sub-region and occupies the remaining volume of the fibrous sheet material.

[0009] Confirmation that a substantially equal number of fibers are present in both the sub-region and the bulk-mass region is achieved by comparing the mass (weight) of the three-dimensional area of the sheet material under the protector (after the protector has been removed (see e.g., an area bounded by a dimension of width A, height a, and depth (not shown) in Fig. 11) with the mass (weight) of a three-dimensional area of sheet material adjacent to the security device having equal width (i.e., the width is equal to the width of the security device ) (see, for example, the area defined by the width B, height b, and depth dimensions (not shown) in Fig. 11). ) in this area is first corrected by returning the mass (weight) of the area currently occupied by the through perforation before comparing the mass (weight) of this area (sub-region) to the mass (weight) of the area of the main oh mass.

[0010] In a second embodiment or aspect of the present invention, the fibrous sheet material has opposing surfaces and one or more paper machine through perforations or "soft edge" through perforations. The surface-applied security device is applied over the through-perforation(s), the shape and size of which may be substantially the same or different from the shape and size of the through-perforation(s). For example, the surface application security device may have a different shape or be larger than the through-perforation, or it may be similar in size and only slightly larger than the through-perforation. In both cases, the fibrous sheeting and the document made from it will be as described above, except that the through-perforation(s) will extend from the recess through the opposite surface of the fibrous sheeting. Therefore, a fibrous sub-region having a three-dimensional volume will be located under or below these recess areas bordering the through-perforation and will extend therefrom towards the outer perimeter of the surface application security device. In other words, as described above, the fibrous subregion will occupy the space below that occupied by the surface application protective device.

[0011] Surprisingly, it has been found that the protective surface application device can be introduced during the wet stage, in which the fibrous web is sufficiently densified, such as a fully formed wet web. By introducing the protector at this wet stage of the papermaking process, the protector can be properly pressed into the fibrous web to further densify the fibers in the sub-region rather than dislodge them. This in turn helps to provide an increase in bonding interaction between the fibers and the overlay protector. As a result, at least one of the following is improved: abrasion resistance, ink adhesion, transverse tear strength, and reverse side translucency. These unexpected benefits eliminate the need for additional processing steps to increase ink adhesion, increase tear strength, or mask backside show-through. Moreover, due to the fact that the protector is inserted during the wet stage in which the fibrous web is sufficiently densified, it becomes possible to press the protector into the fibrous web, hence allowing the use of thicker protectors since the difference in sheet thickness can be substantially reduced. . Therefore, the resulting difference in sheet thickness has less effect on downstream processes.

[0012] Through the methods provided herein, Applicant has also unexpectedly found that a surface application security device can be applied in precise alignment with at least one other element in a fibrous web, fibrous sheeting, or resulting document. In a second aspect of the present invention, the overlay security device is applied in precise alignment with the perforation(s). As will be appreciated by those skilled in the art, applying the security device in precise alignment with another element in the fibrous web greatly enhances the security against counterfeiting of the resulting sheeting or document. Moreover, due to the fact that the security device is introduced during the wet stage of the fibrous web manufacturing process, it becomes possible to correct the alignment during the paper manufacturing process. Accordingly, additional processing steps that would otherwise be necessary to correct the offset of the security device relative to other elements are eliminated. The continuous insertion of the security device also eliminates the need for a carrier substrate because the security device can be cut/stamped and inserted into the fibrous web with a single inserter. As used herein, the term "insertion device" refers to a device used to cut/stamp or insert a security device into a fibrous web during the wet stage. Suitable insertion devices are described later in this document.

[0013] Those skilled in the art will be able to recognize other features and advantages of the invention with the help of the following detailed description and drawings. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as generally understood by a person skilled in the art to which the present invention pertains. All publications, patent applications, patents and other references mentioned in this document are incorporated herein by reference in their entirety. In the event of conflict, the present description, including definitions, shall prevail. In addition, the materials, methods, and examples are illustrative only and are not restrictive. Moreover, all ranges explicitly described herein also cover all subranges by implication.

BRIEF DESCRIPTION OF GRAPHICS

[0014] The present invention may be better understood with reference to the following drawings. The components shown in the drawings are not necessarily drawn to scale, but emphasis is placed on accurately illustrating the principles of the present invention. Although exemplary embodiments are described in connection with the drawings, this is not intended to limit the present invention to the embodiment or embodiments described herein. On the contrary, the aim is to cover all alternatives, modifications and equivalents.

[0015] Specific features of the described invention are illustrated by reference to the accompanying drawings, in which:

[0016] in FIG. 1 is a cross-sectional side view of a fibrous sheet material obtained by inserting a security device into the fibrous web during the wet stage of papermaking where the fibrous web is not sufficiently compacted;

[0017] in FIG. 2 is a cross-sectional side view of a fibrous sheet material obtained by applying a security device to a fibrous web during or after a dry papermaking stage where the moisture content is too low to allow the security device to be pressed into a substrate to further densify the fibers;

[0018] in FIG. 3 is a cross-sectional side view of an exemplary embodiment of the fibrous sheet material of the present invention with its surface application security device, where the surface application security device is inserted into or onto the fibrous web when the fibrous web has been sufficiently densified;

[0019] in FIG. 4 is a schematic representation of a long wire paper machine in which a solid web guard is introduced into the wire web being formed after the wet line and before the couch roll;

[0020] in FIG. 5 is a plan view of an example embodiment of a document in accordance with the present invention that has a plurality of discrete surface applied security devices (patches and stripes) applied thereto;

[0021] in FIG. 6 is a plan view of another exemplary embodiment of a document in accordance with the present invention that has a plurality of discrete surface application security devices (patches) that are applied in precise alignment with another element in the document, such as a watermark;

[0022] in FIG. 7A is a plan view of the front side of a fibrous web or document obtained by inserting a security device into a fibrous web being formed during a wet papermaking step in which the fibrous web is not sufficiently densified after the fibrous web or document has been subjected to one (1) cycle during the simulation test;

in fig. 7B is a plan view of the reverse side of a fibrous web or document obtained by inserting a security device into a fibrous web during the wet stage of papermaking where the fibrous web is not sufficiently compacted after it has gone through one (1) cycle in during the test for imitation of circulation and was shown;

[0023] in FIG. 8A is a plan view of the front side of an exemplary embodiment of a fibrous sheet or document in accordance with the present invention, obtained by inserting a security device into the fibrous web being formed during the wet stage of papermaking, on which the fibrous web is sufficiently densified, after the fibrous sheet material or document was subjected to one (1) cycle in a simulated handling test;

[0024] in FIG. 8B is a plan view of the reverse side of an exemplary embodiment of a fibrous sheet or document in accordance with the present invention obtained by inserting a security device into the fibrous web during the wet stage of papermaking, in which the fibrous web is sufficiently densified after the fibrous web is the sheeting or document was subjected to one (1) cycle in a simulated handling test;

[0025] in FIG. 9A is a plan view of the front side of a fibrous web or document obtained by inserting a security device into a fibrous web being formed during a wet papermaking step in which the fibrous web is not sufficiently densified after the fibrous web or document has been subjected to three (3) cycles during the simulation test;

[0026] in FIG. 9B is a plan view of the reverse side of a fibrous web or document obtained by inserting a security device into a fibrous web being formed during a wet papermaking step in which the fibrous web is not sufficiently densified after the fibrous web or document has been subjected to three (3) cycles during the simulation test;

[0027] in FIG. 10A is a plan view of the front side of an exemplary embodiment of a fibrous sheet or document in accordance with the present invention obtained by inserting a security device into the fibrous web during the wet stage of papermaking, in which the fibrous web is sufficiently densified after the fibrous web is the sheet or document was subjected to three (3) cycles in a simulated handling test;

[0028] in FIG. 10B is a plan view of the reverse side of an exemplary embodiment of a fibrous sheet material or document in accordance with the present invention obtained by inserting a security device into the fibrous web during the wet stage of papermaking, in which the fibrous web is sufficiently densified after the fibrous sheet the material or document was subjected to three (3) cycles in a simulated handling test;

[0029] in FIG. 11 is a cross-sectional side view of another exemplary embodiment of a fibrous sheet material of the present invention (second aspect) obtained by inserting a security device into a fibrous web having opposite surfaces and a paper machine or "soft edge" through-perforation. . The security device is inserted into or onto the fibrous web when the fibrous web is sufficiently compacted; and

[0030] in FIG. 12 is a schematic representation of a long wire paper machine in which through-perforations are made in the web to be formed with a patterned forming wire, and then a protective device, in the form of a continuous web, is inserted into the web after the wet line and before the couch roll. The patterned forming wire is illustrated in FIG. 12A before the stock is discharged from the headbox onto the forming wire, the same forming wire being illustrated in FIG. 12B after the pulp has been discharged onto the wire mesh.

DETAILED DESCRIPTION

[0031] In addition, the invention will be understood from the following details, which are presented as descriptions of some examples of embodiments of the claimed invention.

[0032] By means of the method of the present invention, a fibrous sheet material is provided containing a surface application protective device. In a first aspect of the invention, a method is provided for surface application of a security device to a fibrous sheet material. The method includes introducing a security device into or onto the fibrous web during papermaking. In a second aspect, the method includes forming one or more "soft edge" through perforations in the fibrous web during papermaking, before the fibrous web is sufficiently densified, and then inserting a security device into or on the fibrous web over the one or more through perforations. "with soft edges" after the fibrous web has become sufficiently compacted. Due to the molding of the through-perforations during papermaking, the through-perforations thus contain characteristic edge irregularities which serve as authentic features having a high degree of security. Moreover, due to the introduction of the safety device during the papermaking process, the known processing steps are not interrupted and additional processing steps are eliminated. In addition, due to the introduction of the security device during the wet stage of papermaking, a thicker security device can be applied in this way compared to that applied during the dry stage of papermaking.

[0033] In one embodiment, the method further comprises further compacting the fibers in the sub-region. To further densify the fibers in the sub-region, the surface application protector is pressed into a sufficiently densified (either evenly or unevenly) fibrous web. The fibers densify in this region so that although the volume of the subregion decreases, the number of fibers in this region does not shift; at least not in any significant amounts. The fact that the fibers in this area are not dislodged significantly reduces, if not eliminates, the chance that the perforation(s) will close or block when the fibers in this area are further compacted.

[0034] As used herein, the term "sufficiently densified" as used herein means that the fibrous web is in a fully formed wet web state. At this wet web stage, the fibrous web contains less than 98% water and/or moisture. Accordingly, the fibrous web contains more than 2% fiber or cellulose. In another embodiment, the fibrous web contains less than 95% water and/or moisture with the remaining 5% fiber and/or cellulose components. In a more preferred embodiment, the water and/or moisture content of the fibrous web is in the range of from about 60% to less than 98%, or from about 60% to about 95%. The Applicant has found that a water and/or moisture content above 98% causes the fibers to shift when the protective device is inserted. Significant displacement of the fibers, especially in the sub-region of the substrate, results in little interaction between the security device and the fibers in the substrate. In particular, the displacement of the fibers reduces the wear resistance and strength of the substrate and reduces the masking effect provided in the sub-region and in the region of the kink line. As noted herein, these weak interactions, especially at adjacent edges of the security device, lead to the above problems. Accordingly, it has been found that in the case where the fibrous web contains less than 60% water and/or moisture, the introduction of the security device during the papermaking process does not allow the security device to be sufficiently deepened to accommodate a thicker security device while still maintaining a low value of difference in sheet thickness. Moreover, below 60% water and/or moisture, the fibers in the sub-region are not further compacted to sufficiently fix the fibers near the adjacent edges of the security device. The term "recessed" as used herein refers to pressing the security device into the fibrous web to form a protrusion/depression in the surface of the substrate of the fibrous sheet material such that at least a portion of the security device is vertically recessed below the surface height of the bulk region, while the region the top or top surface of the protective device remains exposed.

[0035] The wet stage, as described above, can be adjusted to be present at different locations along the paper machine, and the present invention embraces all of these possibilities. However, in a preferred embodiment, the protective device is applied to or on the web being formed during the wet stage of the papermaking process, e.g., on or near a couch roll or similar paper machine tool, when the web is a sufficiently densified or fully formed wet web (t i.e. containing a moisture or water level of less than 98% by weight of the fibrous web, preferably from about 60% to less than 98% by weight of the fibrous web, or more preferably from about 60% to about 95% by weight of the fibrous web, or from about 60 % to about 90% by weight of the fibrous web, based on the total weight of the fibrous web). At such locations, there is no need for additional process adjustments to ensure that the safety device is built into the recess. For example, suction boxes are usually placed directly in front of the couch roll to remove moisture as far as possible before the web exits the wet end of the machine to minimize stress on the dryer end of the machine. Similarly, when exiting the cylindrical portion of the cylindrical paper machine (and after the couch roll), the fibrous web will preferably be comprised of about 75% to about 95% water and/or moisture and about 5% to about 25% cellulose or fiber.

[0036] While several papermaking steps on a long wire paper machine are contemplated to provide sufficient densification (as described herein) of the fibrous web, in the preferred embodiment, the papermaking step in which the security device is introduced into the fibrous web is immediately after the wet lines and in front of the couch shaft. That is, at the point where water is no longer visible on the surface of the upper side of the fibrous web. In an alternative embodiment, the security device is inserted into the fibrous web at or before the vacuum box at the wet end, which helps to advantageously install the device into the web. Preferably, the protective device is placed directly on the front surface of the fibrous web by means of a feed wheel, roller or contact shoe.

[0037] In one embodiment, when moving past or beyond the couch roll, the fibrous web is in a fully formed web with a protective surface application device as it moves towards the dry end of the paper machine, which contains both the press section and the dryer section.

[0038] The press section of both types of paper machines removes water and/or moisture by compressing the wet paper between rollers and felt rollers to reduce the water and/or moisture content to the desired level. Applicant has also surprisingly found that compressing a fully formed wet web with a surface-applied security device causes additional densification of the fibers in the subregion (i.e., the area of the fibrous web that is below or under the inserted security device) as they are densified rather than displaced. As a result, the strength characteristics of the resulting fibrous sheet material or the resulting document are improved, as well as the opacity of the back side, which allows the security device to be masked to reduce back side show-through.

[0039] The security devices of the present invention can be of various thicknesses. However, it has been found that the process of the present invention advantageously allows the surface application of protective devices which are as thick as possible. In one embodiment, the security devices are up to 100 micrometers (µm) thick. In another embodiment, the security device has a thickness in the range of 5 to 75 microns, or more preferably 10 to 50 microns. The width of the guards is only limited by the width of the fibrous sheet material. In a preferred embodiment, the width is in the range of 0.25 to 20 millimeters (mm); more preferably 0.5 to 15 mm.

[0040] By introducing a security device during the wet stage of papermaking, these security devices can be pressed into the fibrous web to provide a recess in the surface of the resulting fibrous sheet material. The resulting fibrous sheet material contains a protective surface application device, which provides a difference in the thickness of the sheet, without leading to the above disadvantages. In one embodiment, the sheet thickness difference is expressed relative to the thickness of the security device. In this embodiment, the absolute value of the sheet thickness difference is in the range from 0% to about 80% of the thickness of the protective device; preferably less than 10% of the thickness of the protective device.

[0041] In one embodiment, the thickness variation of the sheet is in the range of -10 to about 50 microns. More preferably, the sheet thickness difference is in the range of -5 to 30 µm; or from 0 to 25 µm.

[0042] In some embodiments, the device is thin enough that pressing the protector into the fibrous wet web results in a negative sheet thickness drop (i.e., the thickness or height of the protector is less than the thickness or height of the bulk region). In such embodiments, the sheet thickness difference is best characterized by referring to the absolute value of the sheet thickness difference relative to the thickness of the security device. For example, in one embodiment, the thickness of the security device is less than 25 µm such that when the security device is molded into a fibrous web, the absolute value of the thickness differential of the surface applied security device sheet is in the range of 0% to about 50%; more preferably from 0% to about 30%; even more preferably from about 0% to about 10% of the thickness of the protective device. In one other embodiment, the thickness of the protector is again less than 25 µm, so that further densification of the sub-region by pressing the protector into the fibrous web results in a sheet thickness drop in the range of -10 to 15 µm; preferably -5 to 10 µm.

[0043] Alternatively, in one embodiment, the thickness of the protector is greater than 25 µm, such that further densification of the sub-region by pressing the protector into the fibrous web results in a sheet thickness variation in the range of -10 to 50 µm; preferably -5 to 25 µm, or 0 to 15 µm. In one other embodiment, in which the security device is also greater than 25 microns thick, the absolute difference in sheet thickness relative to the security device is in the range of 0% to about 50%. Preferably, the absolute value of the sheet thickness difference is in the range of 0% to about 20% of the thickness of the protective device.

[0044] The term "couch roll" should be understood by those skilled in the art as a guide or turning roll for a long wire on a long wire paper machine located at the point where the paper web leaves the wire (i.e. the wet end or paper forming section) and the wire mesh returns to the chest roll. The "couch roll" performs the same function on a cylindrical paper machine, in which the long mesh part has been replaced by a cylindrical part. In particular, once the web leaves the cylindrical portion and moves towards the couch roll, the couch roll guides and rotates the web.

[0045] Although it is also assumed that the entire fibrous web has a uniform consistency in terms of water and/or moisture and fiber content, it is also within the scope of the present invention that the fibrous web is non-uniformly sufficiently compacted. For example, in one embodiment, the fibrous web is only sufficiently compacted at or near the insertion point. As used herein, the term "point of insertion" refers to the area in or near the fibrous web that is at least partially covered by the security device. In another embodiment, the fibrous web is only partially sufficiently densified, or sufficiently densified in a gradient or matrix pattern, such that the fibers do not substantially scatter at the point of introduction, which does not lead to the above disadvantages. A sufficiently densified gradient or matrix pattern can be achieved, for example, by selective vacuuming at locations along the fibrous web being formed. Alternatively, in one embodiment, the moisture content is removed from the gradient or matrix sample by applying a radiation source (ie, heat) to remove water from the top surface at selected locations along the fibrous web being formed.

[0046] The introduction of the security device into the fibrous web forms an interface between the security device and the substrate of the fibrous web resulting from the sheet material or from the resulting document. The term interface as used herein can mean either direct or indirect contact between the security device and the substrate. Where the interface is direct, the protective device is in direct contact with the fibers in the substrate. However, it is contemplated that the security device forms an indirect interface zone with the substrate along some or all of the bottom and side surfaces. For example, the interface may contain other materials between the security device and the substrate. While various materials are contemplated, additional fibrous or polymeric materials are particularly suitable, e.g. monocomponent and/or multicomponent fibers derived from natural sources such as vegetable sources or spun from molten polymer compositions, etc., individually or in combination. Moreover, adhesive materials are preferred for forming an indirect interface zone. Activated adhesives can be used to secure or bond a security device to or within a recessed surface of a fibrous web. Suitable adhesives are not limited to and include, but are not limited to, water, heat and/or pressure activated adhesives that are activated in the dryer section of a paper machine where temperatures reach between 100°C and 160°C. These coatings can be applied as solvent-based polymer solutions or aqueous solutions or dispersions. Suitable dispersions are selected from the group consisting of: acrylic resin dispersions, epoxy resin dispersions, natural latex dispersions, polyurethane resin dispersions, polyvinyl acetate resin dispersions, polyvinyl alcohol resin dispersions, urea-formaldehyde resin dispersions, vinyl acetate resin dispersions, ethylene-vinyl acetate copolymer dispersions, resin dispersions ethylene-vinyl alcohol, polyester resin dispersions and mixtures thereof. As it moves past the couch roll, the fully formed sheet with the surface protector advances to the dry end of the paper machine, which contains both the press section and the dryer section. The adhesive may alternatively form part of the security device and in such embodiments, the implementation has a thickness in the range from 5 to about 50 microns; preferably from 5 to about 20 microns.

[0047] Security devices suitable for the purposes of the present invention include security devices generally used by those skilled in the art to provide protection against tampering or counterfeiting. In a second aspect of the present invention, the security device is preferably made of a structural film (e.g., polyethylene terephthalate (PET) film) and has a sheet thickness or thickness of at least about 10-15 micrometers that provides the device with sufficient wear resistance to allow it to bridge through perforations (- and). As used herein, the term "structural film" refers to a film with structural integrity that is an integral part of the structure of a security device, and not, for example, a removable carrier film that is commonly used with a transfer foil, or the transfer foil itself. The security devices may be those suitable for alternative or additional application of aesthetic features to the substrate. Suitable security devices may display information that is recognizable by a human, either directly or by means of a device, or may display information that is additionally or alternatively recognizable by a machine. The security device may use one or more of the following elements: demetallized or selectively metallized, magnetic, combined magnetic and metallic or embossed areas or layers, color-changing coatings made with color distortion, iridescent, liquid crystal, photochromic and/or thermochromic materials, coatings of luminescent and/or magnetic materials, holographic and/or diffractive security features and micro-optical security features. In a preferred embodiment, the security device provides security such that a secure or valuable document can be easily verified for authenticity. In one embodiment, the security device comprises an array of focusing elements and an array of icons, wherein the array of focusing elements and icons are arranged such that one or more artificially generated images are projected by the security device. The focusing elements used in the present image are intended to highlight, enlarge, highlight, or shade a small dot in an array of icons, and include, but are not limited to, both stepped lenses and non-cylindrical lenses (ie, microlenses). The artificially generated image mentioned above is a form of composite image in that the image that is recognized by the viewer is artificially created from hundreds or thousands of individual image fragments magnified by lenses (i.e. microlenses) and projected towards the viewer's eyes.

[0048] In an exemplary embodiment, the security device is a microlens security device. Such devices generally comprise: (a) a light-transmitting polymer substrate, (b) an arrangement of micro-sized icons located on or within the polymer substrate, and (c) an arrangement of focusing elements (eg, microlenses). The pictogram and the focusing element arrangement are configured such that when the pictogram arrangement is visible through the focusing element arrangement, one or more artificially generated images are projected. These projected images can exhibit a number of different optical effects. Material structures capable of producing such effects are described in Steenblik et al. US Pat. No. 7,333,268, Steenblik et al. issued by Commander et al., US patent No. 8149511 issued to Kaule et al.; US Pat. No. 8,878,844 to Kaule et al.; US Pat. No. 8,786,521 to Kaule et al.; EP 2162294 to Kaule et al.; European Patent Application No. 08759342.2 (or European Publication No. 2164713) issued to Kaule. These references are incorporated herein in their entirety.

[0049] In a preferred embodiment, the security device that is surface-applied by the method of the present invention includes, among other things, micro-optical security devices, such as the MOTION™ micro-optical security device, which is described, for example, in US patent No. 7333268, micro-optical RAPID™ security device, holographic security devices (eg metallized holographic devices). These devices are supplied by Crane Currency US, LLC, Massachusetts, USA. Other suitable devices include, but are not limited to, optically variable devices (OVDs) such as the KINEGRAM™ optical data carrier and color distortion security devices.

[0050] While the security device can be provided in various forms for insertion into the fibrous web, the most preferred security device has been found to be in the form of a continuous web. By providing the security device as a continuous web, it has been found that the security device can be continuously introduced into the fibrous web. The continuous web is then sectioned or divided into a plurality of discrete security devices. The sectioning of the continuous web in discrete security devices can be accomplished by various cutting and/or stamping techniques. In a preferred embodiment, the method is an in-line process of applying a plurality of discrete security devices, without the use of a carrier film, to the fibrous web during manufacture on a paper machine. This method includes providing a protective device in the form of a continuous web; continuously cutting or stamping the continuous web into discrete security devices each of the desired shape and size; and then continuously applying discrete security devices to the fibrous web during papermaking.

[0051] It is contemplated herein that additional protective devices may be applied to the fibrous sheet material; either by surface application, or partial penetration, or complete penetration. For example, in one embodiment of the invention, an additional protective device is applied to the surface of the fibrous sheet material. Said additional device may be introduced into the fibrous web prior to the introduction or application of the surface application security device or after the introduction of the surface application security device. The additional security device may be different or similar to the overlay protection device. For example, in one embodiment, when one of the discrete devices has a thickness of 25 microns or less, it is assumed that it is introduced into the fibrous web when the moisture content is less than 60%; preferably is in the range from about 90% to 0% by weight. For example, a security device is introduced into the fibrous web as it travels through the paper machine between the first dryer section and the size press, and optionally rewetted to increase the water and/or moisture content from about 4% to about 7%.

[0052] Security devices can be of different sizes, shapes or colors. For example, it is contemplated that the security device in the form of a discrete security device takes the non-limiting form of a strip, strip, thread, tape, or patch. These devices may have an overall width of about 2 to about 25 mm (preferably about 6 to about 12 mm) and an overall thickness of about 10 to about 50 micrometers (preferably about 20 to about 40 micrometers). In a preferred embodiment, the security device is a strip or patch. The term "strip" as used herein refers to a security device having a longitudinal dimension in length that is substantially larger than its transverse dimension in width. The "flap", on the contrary, may have essentially equal longitudinal and transverse lengths, and may have the same or different unequal shapes. Various shapes and sizes of strips and patches are contemplated herein. However, while the strip or flap may extend to the edge of the fibrous sheeting or resulting document, in a preferred embodiment, the strip or flap is located within the perimeter of the fibrous sheeting or document and does not extend to the edge of the sheeting or document.

[0053] As noted, different sizes of security devices are suitable for the method and fibrous sheet material of the present invention. In one embodiment, the overall length dimension is in the range of from about 5 to about 75 mm, preferably from about 15 mm to about 40 mm and; overall width from 2 mm to about 50 mm, preferably from about 6 mm to about 25 mm; and a total thickness of from about 10 to about 50 micrometers, preferably from about 15 micrometers to about 40 micrometers. All numerical ranges specified herein include all sub-ranges including integers and fractions. As noted above, in the second aspect of the present invention, the security device is preferably made of a structural film (e.g., polyethylene terephthalate (PET) film) and has a sheet thickness or thickness of at least about 10-15 micrometers that provides the device with sufficient wear resistance to allow it to overlap through perforation(s).

[0054] As noted above, various forms are also suitable for protective devices; for example patches, stripes or threads, geometric shapes such as stars, parallelograms, polygons (eg hexagons, octagons, etc.), numbers, letters and various symbols. Simple and complex non-geometric designs are also suitable. These shapes and designs can be cut using a rotary die process.

[0055] In one embodiment of the method of the present invention, the security device is inserted into the fibrous web being formed such that it is precisely aligned with at least one other element on or in the substrate of the fibrous web, fibrous sheeting, or resulting document. In some embodiments, the security device is inserted such that a certain element within the security device is precisely aligned with another element in the fibrous web, the resulting fibrous sheeting or document. At least one other element can be changed, if necessary, relative to the application. For example, at least one other element is a watermark, a printed image, an embossed structure, another security device, or a paper-limited element. In a second aspect of the present invention, the security device is inserted such that it preferably aligns accurately with one or more "soft edge" through perforations. By inserting the security device into the fibrous web in such a way that it is precisely aligned, it is assumed that the security device, first presented as a continuous web, is delivered to an item of equipment or system (referred to herein as an insertion device) that can be used to cut /stamping a solid web onto discrete safety devices. While it is possible to use a separate device to cut and then apply the security device to the fibrous web, it is preferred that the system used to form the discrete security devices is also used to apply the security devices to or on the fibrous web. With a single device, it is possible to more accurately apply the protective device in precise alignment because it requires fewer moving parts.

[0056] In a preferred embodiment in which the continuous web is cut into discrete security devices, which are then inserted into or onto the fibrous web via the same insertion devices, it is also contemplated that the location of the security device is adjusted by the inserter such that not exactly aligned (displaced relative to at least one other element) the protective device can be continuously corrected until the exact alignment. By using a single inserter for cutting, applying, and in-place fine-registration adjustments in the papermaking process, additional processing for placement adjustments becomes unnecessary. For example, precise alignment during application and adjustments during the papermaking process eliminates the need for additional processing of the resulting sheeting or document prior to printing.

[0057] Suitable insertion devices will be apparent to those skilled in the art in retrospect of the present invention. However, in a preferred embodiment, the inserter is a system that uses either an optical sensor or a fiber density sensor to control precise alignment between the security device and at least one other element in the fibrous web, fibrous sheeting, or resulting document. Given the determined or calculated location of the security device, or the relative locations of the security device and at least one other element, the inserter is used to make adjustments to the placement of the security device. To make such adjustments, the inserter uses a variable speed travel device (eg, a servo motor) that controls tension on the continuous web so that the discrete protector can be applied with the desired precise alignment. Thus, the insertion point of the security device is continuously adjusted by modulating the tension of the continuous web. Alternatively, the inserter may be a rotary die cutter and the transfer device such as is used in the label industry to apply labels in precise alignment.

[0058] In a second aspect of the invention, a method is provided for forming one or more "soft edge" through-perforations in a fibrous web to be formed, followed by surface application of a security device over the through-perforations(s). In this second aspect, the method includes forming one or more "soft edge" perforations through the fibrous web to be formed during papermaking and after the fibrous web has been sufficiently compacted (uniformly or unevenly), inserting a security device into or onto the fibrous web to be formed. over one or more through perforations "with soft edges".

[0059] While the second aspect of the present invention is described as comprising a security device positioned over the perforation(s), the security device and the perforation(s) may otherwise be accurately aligned, or not at all. For example, the security device and the through-perforations(s) may be combined in an adjacent configuration with the security device adjacent to the through-hole(s) on/in the fibrous web.

[0060] In one embodiment of the method of the present invention, the method further comprises further compacting the fibers in a subregion of the fibrous sheet material. To further densify the fibers in the sub-region, the surface application protector is pressed into a sufficiently densified fibrous web. The fibers are compacted in this region so that although the volume of the sub-region is reduced, the number of fibers in this region (surrounding the through-perforation(s)) is not displaced; at least not in any significant amounts. As noted above, the fact that the fibers in this area are not dislodged significantly reduces, if not eliminates, the likelihood that the perforation(s) will close or block, with the fibers in this area being further compacted.

[0061] The through-perforation(s) are performed during the wet web step of papermaking, before the resulting fibrous web becomes "sufficiently densified". In other words, the fibrous web is in an incompletely formed wet web state. Accordingly, the fibrous web has a water and/or moisture content greater than 98% by weight of the fibrous web. In order to make these through-holes, the paper machine screen must contain one watertight element that prevents the sheet from forming in this area. The papermaking screen may be a continuously moving forming wire of a long wire paper machine or a cylinder of a sheeter cylinder paper machine.

[0062] The through perforation may take any suitable size and shape or outer contour. For example, the through perforations may be round, oval, star-shaped, parallelogram-shaped (eg, square, rectangular) or trapezoidal, and so on. In an exemplary embodiment, the perforation has at least one transverse dimension that is approximately 1 millimeter (mm) narrower/smaller than the security device placed above it. The transverse dimension refers to a line between two points on the perforation that intersects at least a portion of the security device. Thus, if the perforation diameter is 5 mm, the minimum size of the device should be at least about 6 mm. If the perforation is irregular (eg star-shaped), the narrowest edge of the device should be approximately 1 mm from the widest edge of the perforation. The shape or outer contour of the "soft edge" through-perforation(s) may correspond to or be consistent with the shape or outer contour of the security device and/or the image displayed or projected by the security device.

[0063] After the through-perforation(s) have been made and sufficient sealing has been performed, a protective device is applied over the through-perforation(s). As noted above, in a preferred embodiment, the protective device is applied to or on the fibrous web being formed during the wet stage of the papermaking process, e.g., on or near a couch roll or similar paper machine tool, when the fibrous web is sufficiently densified or fully formed wet web (i.e., containing a moisture or water level of less than 98% by weight of the fibrous web, preferably from about 60% to less than 98% by weight of the fibrous web; or more preferably from about 60% to about 95% by weight of the fibrous web; or from about 60% to about 90% by weight of the fibrous web, based on the total weight of the fibrous web).

[0064] The surface application security device may have the same or a different shape than the through-perforation(s) and may have a size that is significantly larger or only slightly larger than the size of the through-perforation(s). As noted above, the security device may take the non-limiting form of a strip, strip, thread, ribbon, or flap, while the through-perforation may be round, oval, star-shaped, parallelogram-shaped (e.g., square, rectangular), or trapezoidal, or the like. P. In one exemplary embodiment, the surface application security device is an elongated security thread having a width in the range of about 5 to about 20 mm (preferably about 8 to about 12 mm) that extends along all or part of the entire length or width of the fibrous sheet material. made from fibrous fabric. In another exemplary embodiment, the through perforation is circular in shape with a maximum diameter in the range of 5 to 15 mm (preferably about 7 to about 10 mm), wherein the surface applied security device is a patch having a complementary or different shape and having a width and length at least 2 mm more perforation.

[0065] In another aspect of the present invention, a fibrous sheet material is provided. Fibrous sheet material, as described herein, is the result of further processing of fibrous sheet material after the introduction of a protective device. Said post-treatment further includes a drying step which is applied before or after the protective device is pressed into the fibrous web. When the protective device is pressed into the fibrous web, a fibrous sheet material is formed, containing a fibrous region of the main mass and a fibrous subregion.

[0066] In a first aspect, the resulting fibrous sheet material, which has opposing surfaces and a recess in one opposing surface, comprises: a surface application security device disposed in the recess; a fibrous subregion located below the recess; fibrous area of the main mass, located next to the protective device (located in the recess) and the sub-region; and an interfacing zone between the security device and at least one surface of the fibrous sheet material. In a second aspect, the resulting fibrous sheeting has one or more "soft edge" through perforations that extend from the recess to the opposite surface of the fibrous sheeting. As used herein, the reference to the base mass region adjacent to the security device indicates that, in a cross-sectional view, the base mass area is a three-dimensional area adjacent to the security device along the x-axis. As used herein, reference to a sub-region below the security device indicates that in a cross-sectional view, the sub-region is a three-dimensional region along the y-axis that overlaps at least a portion of the security device. The sub-region has a thickness that is less than the thickness of the main body region such that the surface application security device provides a sheet thickness drop that is less than 80% of the thickness of the protection device or, as described above, is within the ranges and implied sub-ranges indicated.

[0067] In one embodiment, the fibers in the sub-region are further compacted such that the number of fibers in the sub-region is substantially equal to the number of fibers in at least the immediately adjacent region of the bulk. In one other embodiment, the number of fibers in the sub-region is substantially equal to the number of fibers in the bulk region. As used herein, the term "substantially equal" refers to the amount of fibers in the bulk and sub-region, and means that the amount of fibers in each area is between 80% and 100% of the amount in the other area; preferably from 90% to 100% and is characterized by grams per square meter (g/m ² ) of fibers. In a preferred embodiment, the amount of fibers in the sub-region is equal to an amount in the range of 80% to about 100% of the bulk area; especially in the area immediately adjacent to the main mass.

[0068] As noted herein, different thicknesses may refer to a suitable protective device. Therefore, various differences in sheet thickness are also assumed. In one embodiment of the fibrous sheet material, the security device has a thickness in the range of about 10 to about 75 micrometers. The difference in sheet thickness is in the range from about -10 to about 30 micrometers; preferably from 0 to about 25 micrometers; preferably from about 0 to about 15 microns.

[0069] In one embodiment of both the first and second aspects of the present invention, the fibrous sheet material exhibits at least one of the following: (1) improved wear resistance, (2) acceptable ink adhesion, (3) improved cross-sectional tensile strength. direction, or (4) reduced see-through of the reverse side. As used herein, the improved wear resistance is characterized by at least one of the following: (a) minimal or reduced damage to the interface compared to such sheet materials that are made when the fibrous web is not sufficiently densified or (b) almost no line influence inflection. These effects can be quantified or qualified using methods known in the industry that mimic the effects of document circulation. For example, the circulation of a banknote can be simulated using a wear test. One such suitable endurance test is the Circulation Simulation Test (CST). This is a wear and tear test designed to come close to the mechanical and optical degradation that a banknote undergoes during its entire circulation life cycle. This test is performed by attaching rubber bushings, each weighing 7.5 grams, to the four corners of the banknote, and then placing the banknote under weight in a stone drum at a speed calibrated to 60 revolutions per minute (RPM, revolutions per minute) for a fixed period time 30 minutes (one (1) cycle). The tipping action to which a banknote under load is subjected causes a deterioration in the mechanical and optical properties. Controlled amounts of liquid and solid contaminants (such as soybean oil and clay) are then added to the stone drum to simulate the effects of the oils and dirt that a banknote would normally come into contact with during its life cycle. The banknote is inspected before and after each cycle of simulated deterioration for mechanical wear (e.g. edge damage in the form of perforations, tears, cuts, kink lines, loose parts and rough jagged edges, loss of tensile strength, flexural durability, tear resistance and perforation resistance ), optical degradation (such as color degradation of printing ink), and contamination. Kink line effects and interface tear are examples of mechanical deterioration that is generally acceptable for this wear test.

[0070] Acceptable ink adhesion tests are known to those skilled in the art. For example, set off, which is the amount of ink that is transferred from one sheet to another in a stacked collection of a plurality of fibrous sheet materials or documents, can be quantified by methods known to those skilled in the art. Likewise, tensile strength and reverse side translucency can be quantified by methods known to those skilled in the art. For example, translucency can be quantified by known reflectance or transmittance tests. When tested for tensile strength in the transverse direction (using, for example, the ^INSTRON® tensile tester or tensile tester, and as shown in Table 2 below herein, paper made in accordance with the present invention, showed an increase in transverse tensile strength, with properties tested having an increased value ranging from about 90% to about 100%, compared to conventional application with a protector barrel to a fully formed fibrous web.

[0071] The fibrous sheet material has been noted to have a fibrous sub-region below the guard and a fibrous bulk region adjacent to the guard and the sub-region. Because the security device was introduced when the fibrous web was sufficiently densified, the fibers in a region of the fibrous web that corresponds to a sub-region in the sheet material were not displaced in an amount that would lead to these disadvantages. For this reason, the number of fibers in the fibrous sub-region is substantially equal to the number of fibers in at least the immediately adjacent area of the bulk. As used herein, the term "immediately adjoining main mass region" refers to a three-dimensional region in the main mass region that is adjacent to the sub-region and recessed portion of the security device. The immediately adjacent main mass region extends in the radial direction from the recessed portion and the sub-region for a distance on the transverse x-axis that is equal to the length of the x-axis of the sub-region. Considering the difference in volume between the immediately adjacent main body region and the sub-region, the density of fibers in the sub-region is higher than the density of fibers in the immediately adjacent region of the main body. The number of fibers in the immediately adjacent region of the main body and sub-region is substantially equal such that given the difference in volume of the two regions, the density in the sub-region is higher than the density in the immediately adjacent region of the main body. In one exemplary embodiment, the amount of fibers in the bulk region is in the range of 88.55 g/m ² to 90.15 g/m ² while the amount of fibers in the sub-region is in the range of 87.26 g/m ² up to 90.69 g/ ^m2 . As used herein, the term "density" refers to the average number of fibers per volume.

[0072] In a second aspect of this invention, a fibrous sheet material that has opposing surfaces, one or more "soft edge" through perforations, and a recess above the one or more through perforations, comprises: a surface application security device disposed in the recess; a fibrous subregion located below the recess, which defines the contours of the through perforation(s); fibrous area of the main mass, located next to the protective device (located in the recess) and the sub-region; and an interface area between the protective device and the fibrous sub-region and the main body region of the fibrous sheet material. The fibrous sub-region extends along the area defined by the outer perimeter of the through-perforation(s) and the outer boundary(s) of the security device.

[0073] As noted herein, there are many security devices suitable for the present invention. However, in one embodiment, the fibrous sheet material comprises a security device having an array of cylindrical and/or non-cylindrical focusing elements and an array of image icons that optically interacts with the focusing elements to produce at least one artificially generated image. In a preferred embodiment, the focusing elements are exclusively either cylindrical lenses or non-cylindrical lenses (eg, microlenses). However, in this document, this lens array is intended to contain a combination of both types of lenses in varying ratios.

[0074] As noted herein, the security device may be in the form of a strip or patch, or other shapes or geometries. In one embodiment, the security device is present in the sheeting in exact alignment with at least one other element in the sheeting. Suitable other elements are described herein.

[0075] In another aspect, the object of the invention is a document containing fibrous sheet material. Various documents are contemplated by the present invention. For example, suitable documents include, but are not limited to, banknotes, securities, cheques, traveler's checks, identification cards, lottery tickets, passports, postage stamps, share certificates, as well as unsecured documents such as stationery and labels, and goods, used for aesthetics. A plurality of security devices may be incorporated into the fibrous web and hence a plurality of security devices may be applied to the fibrous web and any resulting document. Alternatively, in one embodiment, the document comprises at least one surface applied security device and at least one other security device, such as a recessed or partially recessed security device or security feature. The overlay security device may be fully compatible with other elements of the document, such as other security devices or security or decorative elements.

[0076] Fibrous sheet material suitable for use in the present invention is paper or paper-like sheet materials. These sheet materials, which are single or multi-sheet materials, can be made from a wide range of fiber types, including synthetic or natural fibers or their composition. For example, these sheet materials can be made from fibers such as manila hemp, cotton, flax, wood pulp, and mixtures thereof. As is well known to those skilled in the art, blends of cotton and cotton/linen or cotton/synthetic fibers are preferred for bank notes, while wood pulp is commonly used in non-bank security documents.

[0077] As noted above, security devices for use with the present invention may take a number of different forms, including, but not limited to, strips, bands, threads, ribbons, or patches (e.g., microlens, holographic, and/or color distorted). security threads).

[0078] A further understanding of the claimed invention will be facilitated by the following description of the figures, which represent exemplary embodiments.

[0079] Conventional techniques are illustrated in FIG. 1 and FIG. 2. Basically, as shown in FIG. 1, the security device (11) is inserted in the wet stage of papermaking to recess the device (11) into the fibrous sheet material or document (10). When this method is used for surface application of a security device, the resulting fibrous sheet material suffers from low handling wear resistance, low transverse tensile strength, and high reverse side translucency. As mentioned elsewhere in this document, it has been found that this is partly due to the displacement of the fibers (15) from the sub-region (12) when the protective device (11) is introduced into the formed fibrous web. As can be seen, the number of fibers in the region (14) of the kink line is significantly reduced. This results in poor interaction between the interfacing zone (17) between the security device and the substrate (18) of the fibrous sheet material or document (10). This is especially noticeable at the mated edges (17a).

[0080] Drawbacks have also been found in the conventional embodiment shown in FIG. 2, in which the security device (21) is introduced during the dry stage of papermaking or after papermaking when the paper is fully densified. Here, the fibers (25) in the sub-region (22) are so completely densified that the protective device (21) cannot be pressed into the substrate (28). As a result, the difference in sheet thickness is large. A large variation in sheet thickness has been associated with poor ink application on the sheet material or document (20). As a consequence, for embodiments in which the protector is added in the dry stage, the protector must be very thin to have a suitable sheet thickness drop.

[0081] At least one of these disadvantages is solved by the present invention. In FIG. 3 illustrates one embodiment of the present invention. Here, in contrast to Fig. 1 and FIG. 2, the protector (31) is inserted in the wet stage when the fibrous web is sufficiently densified so that enough fibers (35) are not displaced from the subregion (32) when the protector is pressed into the substrate (38) of the fibrous sheet material (30) . Rather, the fibers (35) are additionally densified or pressed under the protective device (31) and in the region (34) of the kink line. This results in a strong interaction of the fibers in the mating zone (37) and in particular on the mating edges (37a). Moreover, since the protective device (31) is introduced during the wet stage, it can be pressed into the substrate (38) to ensure that the difference in sheet thickness is small.

[0082] The protective device (41) can be inserted into the fibrous web (49) using various methods and technologies. In the preferred embodiment, which is shown in FIG. 4, the protective device (41) is presented in the form of a continuous web and is continuously applied to the formed fibrous web (49) on a long wire paper machine (40) immediately after the wet line (42) and before the couch roll (44), and between the vacuum boxes ( 45a, 45b) which help to install the protective device into the fibrous web (49).

[0083] FIG. 5 and 6 illustrate fibrous sheet materials or resulting documents (50, 60) of the subject invention containing a plurality of surface applied security devices (52a, 52b, 53, 63a, 63b). The devices (52a, 52b, 53, 63a, 63b) are presented here as patches (53, 63a, 63b) and strips (52a, 52b) of various sizes and shapes. Although not limited in terms of the location of the security device (52a, 52b, 53, 63a, 63b), in one embodiment of the present invention, the security devices (e.g., 53, 63a, 63b) are cut or stamped and applied by means of an inserter (not shown) onto the fibrous web (55) during papermaking so that it is precisely aligned with at least one other feature (e.g., a watermark (61)) in the fibrous web, fibrous sheeting, or resulting document ( 60). In FIG. 6 illustrates an embodiment in which a plurality of security devices applied as patches (63a, 63b) are applied in precise alignment with the watermark (61). The first patch (63a) is applied in perfect transverse alignment with the watermark (61), while the second patch (63b) is applied in longitudinal alignment with the watermark (61). It is also assumed that the security device (63a, 63b) is aligned with the watermark (61) in such a way that at least one element (not shown) in the patch (63a, 63b) is exactly aligned with the watermark (61) or another element in fibrous web, fibrous sheet material or the resulting document (60). Document (50, 60) has edges (59, 69) which, although illustrated here as a side of a parallelogram, can also be illustrated with other shapes with different angles. The security devices (52a, 52b, 53, 63a, 63b) are applied to the fibrous web, fibrous sheet or document so that they do not extend beyond the edge (59, 69) of the document (50, 60). In a preferred embodiment, the protective device is placed on the surface so that it is located at some distance from the edge, without touching.

EXAMPLES

Comparative Example 1 One Cycle of Wear Test of Surface Protector When Fiber Web Is Not Compacted Enough

[0084] In the first comparative example, the fibrous sheet material is made according to a conventional wet stage process in which a security device is introduced into the fibrous web during the papermaking process when the water and/or moisture content of the fibrous web is more than 98%. As a result of the displacement of the fibers, the fibers in the region of the kink line (74) and in the sub-region are displaced, which leads to a decrease in the interaction of the protective device (71) and the fibrous substrate (78) of the fibrous sheet material (70) in these regions. The fibrous sheet material (70) formed according to this process is illustrated in FIG. 7A after one cycle (30 min) during the simulation test. As a result of this one cycle, the fibrous sheet material (70) exhibited poor wear resistance, at least as determined by the propagation of the influence of the kink line, as shown in the area (74) of the kink line. The protective device (71) is separated from the substrate (78) of the fibrous sheet material (70) at points along the mating edges (77a).

[0085] Moreover, the overlay security device exhibited backside see-through. A group of five (5) people (P1, P2, P3, P4, P5) were asked to rate the degree of backside translucency from 1 to 5, with 5 being the most translucent and 1 being the least translucent. Experts P1 and P4 rated the see-through of the reverse side as 4; experts P2, P3, and P5 rated the reverse side show-through as 5. In FIG. 7B illustrates fibrous sheet material (70) showing reverse side show-through. To solve this problem, some kind of camouflage coating of the reverse side would be required.

[0086] The transverse tensile strength of the fibrous sheet material was also measured using the ^INSTRON® Model 5965 Tensile Tester. sample. The specimen was then placed in the grips of an Instron Tensile Tester (Model 5965) with the grips spaced 40 mm apart and the filament centered in the gap. The sample was then stretched at a rate of 38 mm/min until the sample broke. This process was repeated 5 times, with the average of the 5 values being the test result that was reported. The results showed that the tensile strength in the transverse direction ranged from 5.4 to 6.3 kg.

Example of the Invention 1. One Cycle of Wear Test of a Surface Protector When the Fibrous Web is Sufficiently Compacted

[0087] In the first example according to the invention, the fibrous sheet material (80) is made in accordance with the invention described herein, in which the protective device (81) is introduced into the fibrous web during the papermaking process, when the moisture content of the fibrous web is less than 98 %. As a result of the reduced displacement from the kinkline region and the increased compaction of the fibers in the sub-region, the protective device (81) interacts sufficiently with the substrate (88) of the fibrous sheet material (80). The fibrous sheet material (80) formed according to this process is illustrated in FIG. 8A after one cycle during the simulated inversion test. As can be seen, the fibrous sheet material (80) has improved wear resistance compared to that obtained in Comparative Example 1. Here, the fibrous sheet material (80) shows no influence of the kink line and damage or separation along the mating edge (87a) of the protective device (81) and substrate (88) fibrous sheet material (80). The fibrous sheet material (80) remains intact, showing improved wear resistance.

[0088] Moreover, the surface application protective device (81) showed less backside show-through compared to Comparative Example 1. A group of five (5) people (P1, P2, P3, P4, P5) were asked to rate the back side show-through from 1 to 5, with 5 corresponding to the greatest translucency, and 1 to the least translucency. Expert P2 rated the translucency of the reverse side as 1; experts P1, P3, P4, and P5 rated the reverse side show-through as 2. In FIG. 8B illustrates a fibrous sheet material showing reverse side show-through. Alternatively, reverse side translucency was characterized by measuring the gray scale density of the transverse yarn. The paper sample was scanned on an Epson V750 high-end flatbed scanner that was calibrated using an IT8 reference target. The paper was scanned at 600 dpi as a gray scale reflected light image with a black background behind the sample. Immediately after capturing the scanned image, a density profile of the selected area was generated. This function selects an area enclosing a filament where the software captures the gray scale value for each pixel in the selected area, for this particular test, with the filament running vertically through the center of the selected area, the software averages the vertical pixels within the area and plots in report the vertical midpoint data point for each horizontal pixel (for example, if an area is 20 pixels high and 200 pixels wide, then for each horizontal position the corresponding vertical pixel values would be averaged and result in 200 data points). The data obtained was then plotted to show if there was any noticeable shift in the gray scale values within the selected area. The results of the density measurements are shown in Table 1. The results of the inventive example are shown in the top row, while the results of the comparative example are shown in the bottom row, indicating a significant drop in fiber density measurement when the measuring device crosses the opposite side of the guard. Lower values indicate high see-through on the back. As can be seen, in the method according to the invention (<90% water and/or moisture), the density values on the fibrous sheet material remain relatively constant, while in the comparative examples (>98% water and/or moisture), the density values decrease significantly. The average greyscale density of the cross yarn for comparative examples (>98% water) is 214; while the average greyscale density of the transverse yarn for the examples of the invention (<90% water) is 226.

[0089] The transverse tensile strength of the fibrous sheet material (80) was also measured with the ^INSTRON® Model 5965 Tensile Tester. The same process as above was repeated here. The results showed that the tensile strength in the transverse direction was better than that shown in comparative example 1. The results of the comparative example are shown as the first columns (>98% water) in table 2, while the results according to the example according to the invention (<90 % water) are shown as the second columns in Table 2.

Comparative Example 2: Three cycles of wear resistance test of a surface application protective device when the fibrous web is not compacted sufficiently

[0090] In the second comparative example, the fibrous sheet material (90) is made according to a conventional wet stage process in which a security device is introduced into the fibrous web during the papermaking process when the moisture content of the fibrous web is more than 98%. As a result of the displacement of the fibers, the fibers in the kink line region and in the sub-region are displaced during the insertion of the security device (91), which leads to a decrease in the interaction of the security device (91) and the substrate (98) of the fibrous sheet material (90) in these areas. The fibrous sheet material (90) formed according to this process is illustrated in FIG. 9A after three cycles during the simulation test. As a result of these three cycles, the fibrous sheet (90) exhibited poor wear resistance, at least as determined by the propagation of the tear effect in the sheet along the mating edge (97a). The fibrous sheet material (90) is torn in two along the mating edge (97a).

[0091] Moreover, the protective device (91) surface application showed through the reverse side. A group of five (5) people (P1, P2, P3, P4, P5) were asked to rate the degree of backside translucency from 1 to 5, with 5 being the most translucent and 1 being the least translucent. Experts P1 and P5 rated the see-through of the reverse side as 5; experts P2, P3, and P4 rated the reverse side show-through as 4. In FIG. 9B illustrates fibrous sheet material (90) showing tearing and showing through on the reverse side. To solve this problem, some kind of camouflage coating of the reverse side would be required.

Inventive Example 2 Three cycles of a wear test of a surface applied protector when the fibrous web is sufficiently densified

[0092] In the second example according to the invention, the fibrous sheet material (100) is made in accordance with the invention described herein, in which the protective device (101) is introduced into the fibrous web during the papermaking process, when the moisture content of the fibrous web is less than 98 %. As a result of the reduced displacement from the kinkline region and the increased compaction of the fibers in the sub-region, as compared to Comparative Example 1, sufficient interaction of the protective device with the substrate (108) of the fibrous sheet material (100) occurs. The fibrous sheet material (100) formed according to this process is illustrated in FIG. 10A after three cycles during the simulation test. As can be seen, the fibrous sheet material (100) has improved wear resistance compared to that obtained in Comparative Example 2. Here, the fibrous sheet material (100) exhibits little or no kink line influence or damage along the mating edge (107a) of the protective device (101), and substrate (108) fibrous sheet material (100). The fibrous sheet material (100) remains intact, showing improved wear resistance.

[0093] Moreover, the surface applied protective device (101) showed less back side show-through compared to Comparative Example 2. A group of five (5) people (P1, P2, P3, P4, P5) were asked to rate the back side show-through from 1 to 5, with 5 corresponding to the greatest translucency, and 1 to the least translucency. The P1 experts rated the see-through of the reverse side as 2; P2, P4, and P5 rated reverse side translucency as 1; and expert P3 rated back side translucency as 3. In FIG. 10B illustrates a fibrous sheet material showing improved reverse side translucency.

[0094] FIG. 11 illustrates one embodiment of the second aspect of the present invention. Here, the fibrous sheet material is indicated by reference numeral 110. A "soft edge" through perforation (111) is formed in the fibrous sheet material (110) in the wet stage of papermaking, before the fibrous sheet material (110) is sufficiently compacted. The protector (112) is then inserted over the through perforation (111) when the fibrous sheet material is sufficiently densified such that enough fibers (113) are not displaced from the subregion (114) when the protector is pressed into the substrate (115) of the fibrous sheet material. (110). Rather, the fibers (113) are further densified or compacted under the protective device (112) in a sub-region (114) delimited by the through-perforation (111) and the kink line region (116). This results in a strong interaction of the fibers in the mating zone (117) and in particular on the mating edges (117a). Moreover, since the protective device (112) is introduced during the wet stage, it can be molded into the substrate (115) to ensure that the difference in sheet thickness is small. In addition, since the fibers do not move in this state, additional sealing in the sub-region (114) significantly reduces (if not eliminates) the likelihood that the through-perforation (111) will close or block.

[0095] As noted above, the through-perforation (111) and the protective device (112) can be introduced into the fibrous sheet material (110) using various methods and technologies. In particular, the paper machine screen may be a continuously moving forming wire of a long wire paper machine or a cylinder of a sheeter cylinder paper machine. In the preferred embodiment, which is shown in FIG. 12, 12A, 12B, the through-perforation (111) is formed with a patterned wire mesh (118) on a long wire paper machine (119) containing at least one waterproof element (120) which prevents sheet formation in this area. The patterned forming wire (118) is illustrated before (FIG. 12A) and after (FIG. 12B) the stock is discharged from the headbox onto the forming wire. As shown in FIG. 12B, sheet forming is prevented in the area of the watertight members (120). After the through-perforations (111) have been formed and the fibrous sheet (110) has become sufficiently compacted, the protective device (112) is formed as a continuous web and continuously applied to the formed fibrous sheet (110) immediately after the wet line (122) and in front of the couch roll (123) and between the vacuum boxes (124a, 124b) which help to install the protective device into the fibrous sheet material (110).

[0096] While various embodiments of the present invention have been described above, it should be understood that they have been presented solely by way of example and not limitation. Thus, the scope and scope of the present invention should not be limited by any of the exemplary embodiments.

Claims (45)

1. Fibrous sheet material (110) having opposite surfaces, a recess in one opposite surface, and one or more through perforations (111) that extend from the recess through another opposite surface of the fibrous sheet material, wherein one or more through perforations are through perforations , formed during the manufacture of paper, and in one or more holes, limited by the mentioned one or more through perforations, fibers pass, and the sheet material contains: fibrous subregion (114), which is located below the recess and which surrounds the mentioned one or more through perforations, and located next to the said recess and fibrous subregion adjacent area of the main mass; protective device (112) surface application, located in the recess above the mentioned one or more through perforations; and zone (117) interface between the protective device for surface application and the fibrous sub-region and the area of the main body, wherein the fibrous subregion contains from 60 to 98% water by weight at the time of application of the surface application protective device. 2. The fibrous sheet material of claim 1, wherein the fibers in the fibrous subregion are further compacted such that the number of fibers in the fibrous subregion is equal to the number of fibers in at least the adjacent bulk region. 3. The fibrous sheet material of claim. 1, wherein said one or more through perforations have characteristic irregularities in the edge region, a maximum diameter or width in the range of 4 to 15 micrometers, and a shape or outer contour selected from the group consisting of round, oval, star-shaped, parallelogram and trapezoidal shapes, or combinations thereof. 4. The fibrous sheet material of claim 3, wherein the shape or outer contour of said one or more through perforations matches or is consistent with the shape or outer contour of the security device, the image displayed or projected by the security device, or both. 5. The fibrous sheet material according to claim 1, wherein the security device is made of a structural film and has a thickness of at least 10 micrometers. 6. The fibrous sheet material of claim. 1, in which the protective device has a thickness in the range from 10 to 75 micrometers or in which the protective surface application device provides a thickness difference of the sheet, which is in the range from -10 to 25 micrometers. 7. The fibrous sheet material according to claim 1, wherein the number of fibers in the fibrous sub-region is equal to the number of fibers in the bulk region adjacent to the recess and the fibrous sub-region, or in which the density of fibers in the fibrous sub-region is higher than the density of fibers in at least the adjacent area of the bulk. 8. The fibrous sheet material of claim 1, wherein the security device comprises an array of cylindrical or non-cylindrical focusing elements and an array of image icons that optically interacts with the focusing elements to produce at least one artificially generated image. 9. Fibrous sheet material according to claim 1, in which the protective device is made in the form of a strip or flap. 10. The fibrous sheet material of claim 1, wherein the security device is precisely aligned with at least one other element on or within the fibrous sheet material. 11. The fibrous sheet material of claim 10, wherein said at least one other element on or within the fibrous sheet material is selected from the group consisting of a watermark, a printed image, a relief structure, a fiber or array of fibers, another security device, or their combinations. 12. A security or value document containing the fibrous sheet material of claim 1. 13. A security or value document according to claim 12, wherein the security device is inserted in such a way that it is precisely aligned with at least one other element on or in the document, wherein said at least one other element on or in the document is selected from the group , consisting of a watermark, printed image, embossed structure, fiber or other security device. 14. The fibrous sheet material according to claim 1, wherein the fibrous sheet material is a bank note, and moreover, the protective surface application device contains an array of cylindrical and/or non-cylindrical focusing elements and an array of image icons that optically interacts with the focusing elements to obtain at least one artificially created image, moreover, the thickness of the fibrous sub-region is less than the thickness of the fibrous region of the main mass, so that a recess with a side wall is formed in the surface of the sheet material, moreover, the surface application protective device is located inside the recess, moreover, the surface application protective device has a thickness in the range from 10 to 40 micrometers and provides a difference in sheet thickness in the range from 0 to 15 micrometers, and wherein the security device is a strip or patch exposed on at least one side of the banknote. 15. The method of surface application of a protective device (112) surface application on a fibrous sheet material (110), including: forming one or more through perforations (111) in the fibrous sheet material during papermaking, with fibers passing through one or more holes defined by said one or more through perforations; inserting a security device into or onto the fibrous web to be formed above said one or more through-perforations at an insertion point during papermaking; and additional compaction of the fibers in the fibrous sub-region (114) of the fibrous sheet material so that the number of fibers in the fibrous sub-region is equal to the number of fibers in at least the adjacent region of the bulk of the fibrous web, wherein the fibrous subregion contains from 60 to 98% water by weight at the time of application of the surface application protective device. 16. The method of claim 15, wherein the fibrous web is compacted such that the water and/or moisture level is less than 95% by weight, based on the total weight of the fibrous web. 17. The method of claim 15, wherein the security device is first presented as a continuous web, which is then cut and placed in or on the fibrous web, or wherein the security device is inserted into or onto the fibrous web in the form of a strip or patch, or wherein the security device is inserted in such a way that it is precisely aligned with at least one other element on or in the fibrous sheet material or document containing the fibrous sheet material, wherein said at least one other element on or in the fibrous sheet material or document is selected from the group consisting of a watermark, printed image, embossed structure, fiber or other security device. 18. The method of claim 15, further comprising: providing a protective device in the form of a continuous sheet; continuously cutting or stamping the continuous web to form patches or strips; wherein the application of the security device comprises continuously introducing patches or strips into the fibrous web over said one or more through-perforations such that a fibrous bulk region, a fibrous sub-region and a negative relief having a side wall are formed in the fibrous web; and wherein the application of the protective device further densifies the fibers in the fibrous sub-region such that the number of fibers in the fibrous sub-region is equal to the number of fibers in at least the adjacent bulk mass region. 19. The method of claim 15 wherein the insertion point of the security device is continuously adjusted by modulating the tension of the continuous web. 20. Fibrous sheet material prepared in accordance with the method of claim 15, wherein the fibrous sheet material comprises a surface application protective device.

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