Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/40—Manufacture
  • B42D25/405—Marking
  • B42D25/425—Marking by deformation, e.g. embossing

Definitions

• Embossing device for embossing micro- or nanostructures
• the invention relates to a device for producing security elements, wherein the security elements on a front side and a
• Rear side of a film web are arranged and consist of embossed structures in a lacquer layer with dimensions in the range of microns or nanometers.
• a device for producing a value document substrate is known from WO 2013/075811 A2, wherein the device in the transport direction of the substrate comprises a device for providing a substrate, in particular a paper substrate, a first film application device for applying a first film element to a first substrate side and a second Foil application device for applying a second film element has on a second substrate side.
• the first film application device and the second film application device are arranged such that the first film element and the second film element are applied to the opposite sides of the substrate without turning the substrate.
• the device has the following facilities in the direction of conveyance of the film web:
• a first embossing unit for embossing first structures having dimensions in the range of micrometers or nanometers into the first lacquer layer, with the film web entering from above or at least obliquely from above into the first embossing unit,
• a second embossing unit for embossing second structures having dimensions in the range of micrometers or nanometers into the second coating Layer wherein the film web enters from below or at least from obliquely below into the second embossing mill.
• the device in the conveying direction of the film web comprises the following devices:
• a first embossing unit for embossing first structures having dimensions in the range of micrometers or nanometers into the first lacquer layer, wherein the foil web enters the first embossing machine from below or at least obliquely from below,
• a second embossing unit for embossing second structures having dimensions in the range of micrometers or nanometers into the second coating layer, wherein the film web enters the second embossing machine from above or at least obliquely from above.
• the first aspect of the invention differs from the second aspect only in that the directions of the inlet of the film Reverse path in the printing or embossing respectively.
• the film web runs in the first printing unit from below or obliquely down, in the first embossing from above or obliquely above, in the second printing unit also from above or obliquely above and in the second embossing again from below or obliquely down, whereas in the second aspect, the film web in the first printing unit from above or
• the film web is first pressed in the conveying direction with the side on which the not yet hardened lacquer layer is, by a impression roller to an embossing cylinder on the surface of which the structures to be embossed are in the micrometer or nanometer range.
• the structures in the micrometer or nanometer range are formed into the lacquer layer.
• the resist layer is cured by ultraviolet radiation from a source of ultraviolet radiation.
• From above in the sense of this invention means that the film web is fed perpendicularly or at least almost vertically from above or in the direction of the weight force or almost in the direction of the weight force on an embossing cylinder of a stamping mill or a printing cylinder of a printing unit.
• At least obliquely from above in the sense of this invention means that the film web is fed at an angle in a range of more than horizontal to almost perpendicular from above on the embossing cylinder or the printing cylinder, the film web in particular not horizontally on the embossing cylinder or the Pressure cylinder is supplied.
• From below in the context of this invention means correspondingly that the film web perpendicular or at least almost vertically from below or against the direction of gravity or almost against the direction of gravity to an embossing cylinder embossing or nen pressure cylinder of a pressure who supplied ks becomes.
• At least obliquely from below in the sense of this invention means that the film web is fed at an angle in a range of more than horizontal to almost vertical from below onto the embossing cylinder or the printing cylinder, wherein the film web is not in particular horizontal on the embossing cylinder or .
• the printing cylinder is supplied.
• front side or back side of the film web are relative terms, which may also be referred to as “the one” and “the opposite” side and which constitute the major part of the total surface of the film web.
• the side surfaces of the film web which are at a thickness of the film web, which is only fractions of a millimeter in card bodies or banknotes only fractions of a millimeter, are negligible and are usually not provided with security elements or coatings or can be.
• the film web is guided from above or at least obliquely from above to the first or second embossing cylinder. It has surprisingly been found that the part of the lacquer of the not yet hardened lacquer layer, which accumulates in the direction of transport immediately before the point at which the lacquer layer touches the embossing cylinder and forms a so-called "lacquer wedge" there, becomes a larger one.
• the paint wedge of the device according to the invention is not distributed unevenly and its geometric Form and distribution are not stochastically pronounced.
• a lacquer layer with predictable and uniform thickness and greater width and a predictable and constant position on the film web is produced on the film web both before, during and after embossing with structures in the micron or nanometer range.
• the reason for this larger wetted area on the surface of the embossing cylinder in the method according to the invention is that the gravitational force leads the lacquer layer in addition to the direction of movement of the film web to the point at which the film web contacts the embossing cylinder.
• the lacquer layer is pulled away from the embossing cylinder by the gravitational force.
• Another advantage of the paint wedge is that due to the larger wetted surface on the surface of the embossing cylinder, the time for the escape of air from the embossing structures on the surface of the embossing cylinder increases, so that the paint layer at higher speed of the film web and the same number of air bubbles in the embossed lacquer layer or alternatively at the same speed of the film web but reduced number of air bubbles can be embossed in the embossed lacquer layer.
• Such structures with dimensions in the range of micrometers or nanometers are used in particular for increasing the protection against counterfeiting of documents of value, in particular bank notes, stocks, bonds, Certificates, vouchers, checks, high-quality admission tickets, but also other papers that are prone to counterfeiting, such as passports and other identification documents, as well as cards, such as credit or debit cards, as well as product security elements such as labels, seals, packaging and the like.
• the structures with dimensions in the range of micrometers or nanometers are, for example, diffractive structures, micromirrors, matt structures or moth-eye structures.
• Embossing are arranged so that the embossed structures are introduced with dimensions in the range of microns or nanometers without turning the film web in the first coat of paint and in the second coat of paint.
• the film web therefore does not have to be guided in a particularly advantageous manner by a turning device in which the film web is rotated in the conveying direction by 180 ° so that the previous front side and the previous back side of the film web are interchanged.
• the leadership of the film web is much quieter, so that the film web neither oscillations or stochastic movements in the plane of the film web still performs in the direction perpendicular to the surface of the film web or such Vibrations or stochastic movements can be largely avoided.
• a device for surface treatment of the rear side of the film web to be arranged by means of corona discharge, atmospheric plasma or flame pretreatment in the direction of transport of the film web in front of the first printing unit.
• a corresponding device for surface treatment of the front side of the film web can also be arranged in the conveying direction of the film web in front of the second printing unit.
• This surface treatment advantageously increases the adhesion and / or course of the front or rear side of the film web for a lacquer layer.
• the thickness of the lacquer layer is preferably 0.5 ⁇ m to 20 ⁇ m, more preferably 2 ⁇ m to 15 ⁇ m, and very particularly preferably 2 ⁇ m to 8 ⁇ m.
• the film web consists for example of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polypropylene (PP) or polycarbonate (PC) with a thickness for security threads or security films of preferably 8 ⁇ to 36 ⁇ , banknotes made of polymer or composite film bank notes to 100 ⁇ or for card body up to 200 ⁇ .
• PET polyethylene terephthalate
• PEN polyethylene naphthalate
• PP polypropylene
• PC polycarbonate
• a third printing unit for applying a wash ink on the second paint layer on the front side of the film web is arranged.
• a printing and printing process is known for example from WO 99/13157 AI.
• a washing ink is applied, with which an overlying ing covering layer, which is applied to the washing ink in a subsequent process, can be removed again with a liquid by washing.
• the cover layer consists, for example, of one or more metallic layers which are vapor-deposited onto the wash ink.
• embossing devices of the prior art embossing cylinders are used with increasing diameter in the direction of movement of the film web to keep the mechanical tension of the film web within the entire printing and embossing device constant.
• the diameter or the circumference of the embossing cylinder becomes larger with increasing distance from the Folienabrollung by 0.1 mm to 0.5 mm.
• a correction of possible deviations between the individual processes takes place via a register control.
• register deviation is corrected by a change in the rotational speed of the corresponding embossing cylinder.
• this disadvantageously creates a difference between the speed of the surface of the embossing cylinder and the speed of the surface of the film web.
• UV embossing however, the hardened structures on the film web or the lacquer layer are so strongly interlocked with the embossing cylinder that this type of correction of registration errors is not possible.
• the first embossing mill has a first embossing cylinder, on the surface of which the first structures to be embossed are located in the micrometer or nanometer range
• the second embossing mill has a second embossing cylinder on its surface the second structures to be embossed are in the micrometer or nanometer range
• the diameter of the first embossing cylinder and the diameter of the second embossing cylinder are the same size and the first and the second embossing cylinder have the same rotational speed.
• the diameter or circumference of both embossing cylinders need not be exactly the same size.
• the second embossing cylinder it is also possible for the second embossing cylinder to have a circumference smaller by up to 2 mm than the first embossing cylinder, so that the circumference of the embossing cylinders, as opposed to embossing devices of the prior art, can become smaller with increasing distance from the film unwinding.
• embossing shafts it can come not only by their manufacturing tolerances, but also by the use of sleeves, since their thickness is also included in the effective scope of the embossing cylinder.
• the sleeves are also subject to significant variations in thickness, since their production is carried out by galvanic molding, which is known to be subject to greater manufacturing tolerances.
• the device is preferably divided into three areas.
• the first area is the device for providing a film web and the first printing unit and the area up to the entrance to the first embossing unit.
• the film is unwound and printed with a varnish layer, which is curable by means of ultraviolet radiation, so-called UV varnish, printed over the entire surface or in the form of a motif.
• the mechanical tension of the film web is set such that the embossing of the first structures is introduced into the first lacquer layer of an elastically stretched film web.
• the second area is formed by the first stamping mill and the area up to the entrance to the second printing unit.
• the mechanical tension of the film web is lowered compared to the first area.
• the film web relaxes and contracts almost elastically, which leads to a shortening of the arc length.
• the third area is the second printing unit and the second stamping unit.
• the mechanical tension of the film web is adjusted so that the arc length of the stretched film web corresponds exactly to the circumference of the second embossing cylinder.
• a registration of the second lacquer layer with respect to the first lacquer layer can be carried out by means of register control, since the printing cylinder must have a certain slip due to the not yet cured lacquer layer.
• the position and geometry of the film web between the embossing of the first structures and the embossing of the second structures can thus be determined or corrected so that the embossing of the first structures and embossing of the second structures in the exact register to each other.
• the film web has a thickness of 12 ⁇ and a width of 810 mm.
• the embossing takes place with a mechanical tension of the film web of 200 N, wherein the first embossing cylinder has a circumference of 500 mm.
• the result is an arc length of 500 mm in the stretched state.
• an adaptation of the mechanical tension of the film web takes place such that the arc length corresponds exactly to the circumference of the second embossing cylinder.
• the embossing of the first structures to the embossing of the second structures is preferably carried out on the basis of register marks, which are automatically read out and lead to a correction of the mechanical tension of the film web.
• register marks such as double wedge marks
• optical register marks such as double wedge marks, can be used, which are additionally introduced into the embossing cylinder and are molded during the embossing process in the paint layer.
• two double wedge marks are read out with a light barrier.
• the time difference between the first double wedge mark and the second double wedge mark is determined from the signals of the light barrier. This time difference must be constant for all register marks, deviations lead to a control intervention, for example an adaptation of the mechanical tension of the film web.
• FIG. 1 is a side view of an inventive device for the production of security elements
• Fig. 2 is a side view of a stamping method according to the prior art
• Fig. 3 in side view an inventive embossing method.
• FIG. 1 shows a side view of a device for producing security elements, which are arranged on a front side and a rear side of a film web and consist of embossed structures in a lacquer layer with dimensions in the range of micrometers or nanometers.
• the device initially has a device 1 for providing a film web 2, wherein the film web 2 has a front side 2.1 and a
• Rear 2.2 has.
• Device 1 consists for example of a coil or drum on which the film web 2 is provided wound and from which the film web 2 is unwound through the device again.
• the film web 2 of a device A to the surface chen aside the back 2.2 of the film web 2 supplied by means of corona discharge, wherein a device 3.1 generates the corona discharge.
• the direction of movement of the film web 2 is represented by arrows 9.
• the film web 2 is supplied to the first printing unit B, which applies a first curable by ultraviolet radiation paint layer on the back 2.2 of the film web 2.
• the film web 2 runs in this case in the direction of the arrow 9 from below or at least from obliquely below into the first printing unit B with the printing cylinder 5.1 a.
• the printing unit B is, for example, a flexographic printing unit.
• the film web 2 runs in a first embossing C, which embosses first structures with dimensions in the range of micrometers or nanometers in the first coat of paint.
• the film web runs in the direction of the arrow 9 from above or at least obliquely from above into the first embossing C with the embossing cylinder 6.1 and the impression roller 7.1, wherein the lacquer layer is cured by ultraviolet radiation of the source 8.1 for ultraviolet radiation.
• the film web 2 runs in a second printing D.
• the surface of the front side 2.1 of the film web 2 is first treated by corona discharge, wherein a device 3.2 generates the corona discharge.
• a printing cylinder 5.2 brings a second coating layer, which is curable by means of ultraviolet radiation, on the front side 2.1 of the film web 2.
• the film web 2 runs in the direction of the arrow 9 from above or at least from obliquely above into the second printing unit D with the printing cylinder 5.2 a.
• the printing unit D is, for example, a flexographic printing unit.
• the film web 2 runs into a second embossing unit E, which embosses second structures with dimensions in the range of micrometers or nanometers into the second paint layer.
• the film web 2 runs in the direction of the arrow 9 from below or at least diagonally from below into the second embossing unit E with the embossing cylinder 6.2 and the impression roller 7.2, wherein the lacquer layer is cured by ultraviolet radiation of the source 8.2 for ultraviolet radiation.
• the film web 2 runs in a third printing unit F, which applies an ink or wash ink on the front side 2.1 of the film web or on the second lacquer layer.
• the film web 2 of a device G for surface treatment of the front side 2.1 of the film web 2 and the second coating layer is supplied by means of corona discharge, wherein a device 3.3 generates the corona discharge. Finally, a device 10 rewinds the film web 2 onto a spool or drum.
• An optional inspection of the back 2.2 of the film web 2 is carried out with the inspection devices 4.1 and 4.2, an inspection of the front 2.1 of the film web 2 is carried out with the inspection device 4.3.
• the inspection devices 4.1, 4.2 and 4.3 are, for example, traversing camera systems which optically monitor the respective surface of the film web 2 or the correspondingly applied paint layers.
• Fig. 2 shows a side view of a known from the prior art embossing method.
• a lacquer layer 16 On a film web 15 is a lacquer layer 16, wherein the film web is fed in the direction of movement 9 obliquely from below to an embossing device.
• the embossing device consists of a Regezy cylinder 11, in the surface to be embossed structures are introduced with dimensions in the range of micrometers or nanometers, a roll-shaped impression roller 12, a source 4 for ultraviolet radiation and two guide rollers 13.
• the film web 15 is deflected by the first guide roller 13 so in that the lacquer layer 16 comes into contact with the embossing cylinder 11.
• the film web 15 together with lacquer layer 6 is pressed by the impression roller 12 against the embossing cylinder 11 and the Molded with dimensions in the range of microns or nanometers in the paint layer 16.
• the lacquer layer 16 is hardened by electromagnetic radiation in the ultraviolet wavelength range of the source 14 and led away from the embossing cylinder 11 via a second deflection roller 13 and fed to subsequent processing steps.
• Fig. 3 shows a side view of the embossing method according to the invention, in which, in contrast to the embossing method of Fig. 2, the film web 15 is fed from obliquely above the embossing device.
• the film web 15 is deflected by the first guide roller 13 such that the lacquer layer 16 comes into contact with the embossing cylinder 11.
• a part of the not yet cured lacquer layer 16 accumulates, forming the paint wedge 19 described above and particularly advantageously evenly formed.
• the film web 15 together with the lacquer layer 16 is pressed against the embossing cylinder by the impression roller 12 Pressed 11 and molded the structures with dimensions in the range of microns or nanometers in the paint layer 16.
• the lacquer layer 16 is hardened by electromagnetic radiation in the ultraviolet wavelength range of the source 14 and is conveyed via a second deflecting element. roller 13 led away from the embossing cylinder 11 and fed to subsequent processing steps.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Printing Methods (AREA)
• Credit Cards Or The Like (AREA)
• Shaping Of Tube Ends By Bending Or Straightening (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Supply, Installation And Extraction Of Printed Sheets Or Plates (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=57396390

Family Applications (1)

Country Status (6)

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Family Cites Families (9)

• 2015
  • 2015-11-27 DE DE102015015378.1A patent/DE102015015378A1/de not_active Withdrawn
• 2016
  • 2016-11-18 CN CN201680069239.1A patent/CN108290438B/zh active Active
  • 2016-11-18 WO PCT/EP2016/001923 patent/WO2017088965A1/fr not_active Ceased
  • 2016-11-18 EP EP16801381.1A patent/EP3380335B1/fr active Active
  • 2016-11-18 DK DK16801381.1T patent/DK3380335T3/da active
  • 2016-11-18 ES ES16801381T patent/ES2751419T3/es active Active

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