Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
  • D21H21/40—Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper
  • D21H21/44—Latent security elements, i.e. detectable or becoming apparent only by use of special verification or tampering devices or methods
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
  • D21H13/36—Inorganic fibres or flakes
  • D21H13/46—Non-siliceous fibres, e.g. from metal oxides
  • D21H13/48—Metal or metallised fibres

Definitions

• the invention relates to a paper, more particularly a security paper, for example a paper for banknotes, for checks, for visas, passports, credit cards, and others.
• a security paper for example a paper for banknotes, for checks, for visas, passports, credit cards, and others.
• These elements can, for example, be shiny, fluorescent, luminescent, metallic, magnetic fibers or flakes or boards, thermochromic, photochromic, iridescent, etc.
• Document FR-A-2 425 937 describes a fibrous structure comprising metallic fibers and its manufacturing process.
• These metallic fibers are incorporated into the coherent structure in a controllable manner, that is to say in limited places and at predetermined concentrations, either on the surface or in the thickness of the structure, for example in the form of strips. .
• the surface deposition in strips is done by arrangement of a secondary headbox containing a dispersion of metallic fibers above the wet section of the paper machine and extending over part of the width of the paper.
• the final paper comprises a strip in which the fibers are distributed randomly, since an aqueous suspension of metallic fibers is deposited, the concentration of the fibers in the strip having a constant average value.
• These fibers can be incorporated into the thickness of the structure.
• a dispersion containing cellulosic fibers and metallic fibers is formed by the papermaking process, then this fibrous sheet is covered with sheets devoid of metallic fibers. This association can take place either on a machine with several flat tables, or outside a paper machine, by laminating.
• such a sheet is called “multi-ply", that is to say it comprises several layers.
• the concentration of the fibers is either zero, at the place where the layer comprising the metallic fibers does not exist, or constant, at the place where the layer comprising the fibers exists. If the fibers are detected by means of a detector, this will transmit a signal equal to either O (zero fiber concentration) or 1 (average fiber concentration C). Consequently, a counterfeiter can deposit fibers at a certain location, this deposit being either constant or random. At the places where the deposit will be zero, the detector will indicate a signal O. At the places where the deposit will be carried out, the detector will indicate a signal 1, whether the deposit is constant or random, the concentration of the fibers finally having a constant mean value, even in the case of a random deposit.
• a detector will not be able to detect authentic papers or counterfeit papers.
• Document US-A-59281 describes a process for manufacturing paper which consists in adding powder or metallic fillers to the pulp. This process essentially consists in introducing the metallic elements in a random manner, for example using a perforated cylinder containing the perforated elements which fall under the effect of gravity on the sheet of paper being formed.
• Document GB-A-696 673 describes a method and an apparatus for spraying elements, for example metallic powder, just before the sheet of paper is formed.
• the elements can be introduced in the form of lines of points or lines according to a sinusoidal or cycloidal curve. We can control the device to deposit the elements using beta rays, but the concentrations are random.
• the object of the invention is therefore to produce in a simple manner a sheet in the form of a fibrous structure comprising particulate security elements arranged inside the thickness of the fibrous structure.
• fibrous structure means any structure obtained by the papermaking route, from an aqueous composition of cellulosic fibers, optionally synthetic fibers, fillers and any other additive used in the papermaking industry. Another object of the invention is to produce a sheet in the form of a fibrous structure comprising particulate elements allowing differentiated variations of recognition signals.
• the invention relates to a paper comprising security elements in the form of particles, characterized in that it consists of at least one jet, the particles being arranged in the thickness of the jet at concentrations C determined variables, over the entire surface or in bands.
• the sheet is monojet.
• the particles are particles in any form, such as fibers, flakes, boards, for example metallic fibers.
• the particles are arranged in the domains D t , D 2 , D 3 , D devisdistinct, the average concentration of the particles Ci, C, C 3 , C n in each domain being determined.
• the particles are arranged in the domains D t , D 2 , D 3 , D hinderdistinct, the average concentration of the particles Ci, C 2 , C 3 , C Pain in each domain being determined.
• the domains Di, D 2 , D 3 , D n are distant from each other, their distance being determined.
• the average concentrations Ci, C 2 , C 3 , C n are distributed along a curve, for example according to a sinusoid.
• the security elements emit detectable physical signals, in particular optical, magnetic, electrical.
• the security elements can be of average concentration Ci in one place, C 2 in another place and C in another place, so that Ci ⁇ C 2 ⁇ C 3 .
• the signal is therefore encrypted and decrypted on reading.
• the invention further relates to a method for producing such a sheet.
• WO 94/11577 (TUMBA) describes a method for producing delimited areas in paper consisting in preventing the paper from being wrung at one or more places on the machine fabric during the formation of a sheet. of paper on the machine, and by depositing on these places a particular composition which contains fibers which are different from the other fibers deposited on the canvas.
• a nozzle which has a lip which rests against the canvas of the round shape, the nozzle having a part which delivers the particular composition in the part which is said "Naked".
• a paper is thus obtained which has transparent parts, but these parts having all the other physical properties which are the same as that of paper.
• the method according to the present invention consists in depositing or introducing the particles when part of the paper jet is formed on the canvas, preferably when the jet is formed halfway.
• the security elements are introduced by means of a fluid, the flow of which is regulated.
• FIG. 1 is an exploded view of a sheet produced according to document FR-A-2 425 937.
• FIG. 2 is an exploded view of a sheet produced according to document US-A-4,437,935.
• Figure 3 is a view of a sheet produced according to the present invention.
• FIG. 4 is a sectional view along line AA of the sheet of FIG. 3.
• Figure 5 is a view of the signal transmitted to a detector.
• FIG. 6 is a view of the device used to produce the sheet according to FIG. 3.
• Figure 7 is a perspective view of another embodiment of the device for producing the sheet according to the invention.
• the sheet 1 shown in Figure 1 is formed of three folds.
• the outer plies 2 and 3 are, for example, fibrous structures obtained on a flat or round table from an aqueous suspension of cellulose fibers, optionally in admixture with synthetic fibers, fillers and other well-known additives of l skilled in the art.
• the inner sheet 4 is a fibrous structure obtained from an aqueous suspension, containing cellulose fibers, security elements 5, possibly synthetic fibers and other additives.
• the security elements are more particularly metallic or magnetic fibers. Because they are introduced into the aqueous suspension, they are distributed randomly.
• the final sheet consists of three folds. In Figure 2, there is shown a sheet 6 formed of two folds 7 and 8. Between these two folds is introduced during their formation by paper, a band 9 soluble in water having security elements which are separated the each other. These security elements are placed at an equidistant distance. Their concentration is constant.
• FIG. 3 represents a sheet 11 according to the invention.
• the sheet 11 according to the invention is such that it includes security elements 12 in the form of particles.
• particles is meant any element of any shape, for example fibers a few tenths of a millimeter long, flakes, planchettes.
• These security elements can be metallic or magnetic.
• the particulate elements 12 are arranged inside the thickness of the sheet 11, as shown in FIG. 4. Preferably, the elements 12 are located substantially half of the thickness e of the sheet 11.
• the sheet 11 is single-jet and the particles 12 are arranged so that their concentrations are variable, but determined.
• concentrations it is meant that at a given location on the sheet the concentration C of the particles 12 is adjusted.
• the concentration of the particles is Ci, in the area D 2 , it is C, in the area D 3 , it is C 3 , in the area D n , the concentration of particles is Cmony.
• the signals transmitted by the particles will therefore follow the same modifications.
• the concentrations C follow a sinusoidal curve, the transmitted signals will have a sinusoidal profile.
• the concentrations C can be adjusted so that the transmitted signals have the desired configuration.
• FIG. 5 shows a sinusoidal signal S obtained from metallic fibers having increasing then decreasing concentrations. Depending on the average distance d between the different domains Di, D 2 , D 3 , Drete, the pitch of the curve of the signal S can be adjusted.
• Figure 6 there is shown a device for carrying out the particle deposition process.
• the round machine shown in 13 consists of a cylinder 14 formed of a canvas which can be embossed to form a watermark in the paper.
• the cylinder 14 rotates in an aqueous suspension of cellulose fibers, possibly synthetic fibers and other known additives.
• the fibers are deposited on the cylinder 14 to form a jet 15 of paper.
• the particles are deposited at the place where the paper jet is half-formed.
• the flow rate of the particles is adjusted for example by means of a valve 18. Depending on whether the flow rate is greater or less, the particles are deposited in a higher or lower concentration.
• the particles can be brought in by means of a fluid such as compressed air or water.
• the jet When the particles are deposited on the half-formed or forming jet, the jet continues to form due to the rotation of the cylinder 14 and is lifted by means of a lifting cloth shown in 19, then to go to a dryer or any other subsequent treatment of the paper throw.
• a whole series 16a, 16b, 16c of tubes 16 can be provided, the ends of which are placed in the vicinity of the canvas of the cylinder, as shown in FIG. 7.
• the ends 17a, 17b, 17c of the tubes are placed above the canvas of the cylinder, without touching the latter.
• the distance between the ends 17a, 17b, 17c of the tubes and the surface of the fabric 14 is adjusted so that the particles are placed inside the jet 15, in formation.

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• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Paper (AREA)
• Credit Cards Or The Like (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9468454

Family Applications (1)

Country Status (8)

Cited By (3)

Families Citing this family (9)

Citations (5)

Family Cites Families (1)

• 1994
  • 1994-11-03 FR FR9413115A patent/FR2726586B1/fr not_active Expired - Fee Related
• 1995
  • 1995-10-24 GB GB9707858A patent/GB2309710B/en not_active Expired - Fee Related
  • 1995-10-24 ES ES009650014A patent/ES2138892B1/es not_active Expired - Fee Related
  • 1995-10-24 DE DE19581817T patent/DE19581817B4/de not_active Expired - Fee Related
  • 1995-10-24 WO PCT/FR1995/001405 patent/WO1996014469A1/fr active IP Right Grant
  • 1995-10-24 BR BR9509557A patent/BR9509557A/pt not_active IP Right Cessation
  • 1995-11-02 IT IT95TO000879A patent/IT1281007B1/it active IP Right Grant
  • 1995-11-03 NL NL1001577A patent/NL1001577C2/nl not_active IP Right Cessation

Patent Citations (6)

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