FI119391B - Process for producing identification marks in paper or cardboard and a marked material created by the method - Google Patents

Description

119391

A method for providing identification markings on paper or board and the labeled material provided by the method

The present invention relates to a method for producing identification markings on a laminated paper or board made in a continuous sheet. In addition, the invention relates to a layered paper or paperboard comprising a process for obtaining identification markings.

Consumer packaging may be marked at the packaging stage with the aim of informing the consumer, for example, of the date of packaging of the product or the date of expiry of the van-10. In addition, markings which may be partly or wholly invisible are made into product identifiers which identify the origin of the product and ensure its authenticity.

Known ways of marking packages are by means of printing inks as well as stamping, stamping or punching on the packaging material. Nowadays, laser marking of packages is on the rise, where the marking is done with a laser beam without physically touching the packaging material and giving it printing ink or other excess material.

The laser beam can affect a fiber-based material such as paper. or cardboard, in different ways. As is known, the laser beam easily burns thin paper, which, ·· *. To counteract this problem, U.S. Patent No. 6,306,493 discloses a finely divided polymeric additive, which • acts as an absorbent and, in addition, ** "" carbonises, leaving a dark mark on the paper. However, according to the applicant's knowledge and experience, it is possible to burn the surface of paper or the like fiber layer with a laser beam to produce a marking imprint without having to pass through the paper without necessarily having to add to the paper pulp or other polymeric additives.

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Other possible laser processing techniques for the fiber layer include cutting or engraving the surface of the layer using an inert shielding gas to prevent material burning. The resulting marking marks are recesses in the fiber-30 surface of the fibrous layer, where at least no significant color change occurs. •] ·. modifying the structure of the backing by reacting or evaporating a component of it with a laser beam may produce a trace which is detectable by the detector '** and thus useful as a tag marking.

2,119,391

Laser marking paper or paperboard according to the aforementioned U.S. Patent No. 6306493 is disclosed for use as packaging material, labels or wrapping paper for various consumer packages, which is marked by targeting a laser beam to the surface of the material. Thus, laser marking is intrinsically linked to the product packaging process. U.S. Pat. No. 5,340,628 describes a laser-labeled layered packaging material wherein a paper layer of polyester or polypropylene is applied to the paper base and passed through the laser beam leaving a mark on the paper layer beneath. The material is intended for use on product packaging labels, where the laser labels contain information specific to the packaging product.

10 As mentioned above, known fiber-based laser marking materials according to the aforementioned publications are intended primarily for labeling purposes at the packaging stage of a product. Identification markings, which serve to verify the authenticity of the product and which are intended primarily to prevent or discourage counterfeiting, are less suitable. The counterfeiter, who copies the product with its 15 packs, naturally also strives to produce genuine imitation laser markings on the packaging.

It is therefore an object of the present invention to provide a solution which enables paper or cardboard, in particular as packaging material, to be provided with a product-specific laser marking which is substantially more difficult to falsify. The starting point of the invention is that at the packaging stage the finished product. or in place of the mark on the packaging which is about to be completed. * ··. is included in the packaging material, paper or board itself, which is ··· of the sandwich construction. The method according to the invention is characterized in that the markings are made on a web beam moving with a laser beam, whereupon a second layer of material is then applied so that the markings remain within the layer structure of the moving web.

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Thus, in the invention, the identification markings are produced on a moving web on an on-line basis by a paper or board machine or by a paper or board web coating unit. Sat. ···. The serrations may be located, for example, in a stationary mounted transverse beam relative to the web, which provides a regular *: **: pattern for the movable web, suitably covering it. The identifier can be any, for example, the logo of a paper or cardboard manufacturer or the manufacturer of a product or the like, and the preferred *:. min it is specific to the product to be packaged. When left inside a layer of paper or cardboard, the identifier is tamper-proof and not easily • · 35 replicated. In order to be successful, the counterfeiter would have to copy the packaging along with the packaging along with the product, which would render the operation unprofitable as far as technically possible.

Laser marking can be done by burning the surface of the fiber layer using a low power density CCV laser source. By using a CO 2 laser source with a higher power density and an inert shielding gas that is antioxidant, the fiber layer can be vaporized to etch the recesses, which serve as detectable markers on the detector through scanning.

Embodiments of the invention include a paperboard comprising two or more overlapping fiber layers, the surface of the web-like fiber layer being labeled prior to the layers being joined together. During the bonding step, the fibrous webs may still be damp, whereby the markings already exist prior to the final drying of the composite web on a board machine and become integral to the resulting ready board. If the markings are recesses formed on the fiber layer, the damp and still elastic fiber layer applied thereto fills the recesses so that the paperboard becomes uniform in thickness and density. However, if the materials of the layers differ, the markings formed by the recesses can still be seen on the finished board. If the materials of the layers differ in their darkness and the recesses are made in the darker layer, the patterns formed by the recesses will appear in the light of the cardboard as being lighter than their surroundings. Correspondingly, the recesses made to the lighter layer stand out from their surroundings. darker. Such differences in darkness or color sufficient for identification are chemical • · ·. ·· *. between the pulp and the chemimechanical or mechanical pulps, and in particular between the white pulp, such as brown kraft pulp and bleached pulp.

In the paper or board made in accordance with the invention, a layer of material applied over the on-line labeled fiber layer may also be a coating paste or adhesive layer applied in the manufacturing process on a paper or board machine, or a polymer coating to be attached to the fiber layer.

··· *. ···. The transparent polymer coating can, for example, leave the identification marks obtained by burning, while being protected from tampering under the coating. The identification markings and subsequent coatings are made in a continuous process according to the invention without interrupting the movement of the web.

The products obtainable according to the invention comprise a composite sheet of paper or paperboard having identification markings which is embossed with a laser beam and embedded within the layer structure of the web. A full 4,119,391 labeled product can be manufactured on a large scale at a paper or board mill, from where it is delivered in rolls to a customer company that uses it as individual product packaging. The material may be multilayer board, coated paper or board, or polymer coated paper or board, and the markings may be hidden under the coating or fiber layer so that they are detectable by scanning or by detector, or the labels may be visible under a transparent polymer coating.

An example of a laser-labeled packaging board according to the invention is a folding boxboard consisting of a triple layer of outer sulphate pulp layers and a middle layer of intermembrane core (CTMP) therein, with markings on consequently are detectable by a detector.

The invention will now be described in more detail by way of example with reference to the accompanying drawing, in which Figure 1 shows a laser marking of a fibrous material web and its subsequent bonding to another web to provide a layered web product; Figure 2 shows a laser marking and Fig. 3 is a sectional view of the web of ΙΠ-ΙΠ in Fig. 2, Fig. 4 shows a layered structure of a cardboard labeled according to the invention, Fig. 5 shows a layered structure of another laser-labeled cardboard, and .. ** Figure 6 shows a layered structure of a third laser-labeled paperboard.

1-3 shows a fibrous material web 1 with a transverse beam 2 disposed along its path, whose identification marks 5 are produced on the web by adjacent laser beams 4 directed to the web surface.

: The mark may consist of a freely selectable Figure 5, such as the company or product name,.,,, 30, logo or trademark, and in the case of Figure 1, form transverse rows of equal · · length on the web. The markings 5 should be on the web in a sufficiently comprehensive manner so that they are sufficient for each sheet or packaging blank to be separated from the layered web later.

The laser heads 3 in Figures 2 and 3 may be low power density CC2 laser light emitters which lightly burn the surface of the web 1 so that the identification markings 5 are darkening due to oxidation of the fiber material. Alternatively, recesses based on the evaporation of the material can be engraved on the surface of the web 1 by means of a CO 2 laser head 3 having a higher power density and a simultaneously inert shielding gas. Further, it is possible for the laser beams 4 to selectively react or evaporate a component of the web material over a given web depth or total web thickness so that the web density or composition changes at the point of marking.

After the marking step, as the web 1 continues to move against it, a second moving web 6 of material is guided in accordance with Figures 1 and 2 so that the webs together form a layered web-shaped article 7. If necessary, an adhesive can be used. The continuous web product 7 is wound on a reel (not shown) and, following any further processing steps, is delivered in the form of a reel, sheet, or preform into individual product packages containing the identification marks 5.

The second web 6 to be connected to the fibrous material web 1, denoted 5, may. 20 also be a web of fibrous material, whereby the web-shaped product 7 is a multi-ply paperboard. In the schematic figures 1 and 2, the layers 1, 6 only show '··· * two, but the cartons may have more layers, and if desired, the identification markings 5 may be provided on several fiber layers or on opposite sides of the same layer.

The second layer of material to be applied to the marked fibrous material web 1 may also be formed by, for example, a polymer film to be laminated therewith or a single or multiple layer extruded polymer coating. It is also possible to laser-tag the fiber web 1 on a paper or board machine, where in the next step: ··· * a coating paste is applied to cover the identification markings.

When the second fibrous material web 6, * ·; · * is inserted against the marked fibrous material web 1, the identification markings 5 remain hidden within the sandwich carton 7, from which, however, the markings are detectable by the detector. If the layers are * ·· «thin enough, the burn marks 5 may also be visible to the naked eye when looking at the material against light. If the marked fibrous web 1 119391 is provided with a transparent polymer coating, the burned marks 5 are visible through the polymer layer.

Figure 4 illustrates, as an example of the layered products obtained in accordance with the invention, a three-ply paperboard 7 whose middle layer 1 has a fibrous material different from the fibrous material 6, 8 experienced. The material of the middle layer 1 may be e.g. CTMP, and the outer layers 6,8 may be e.g. bleached sulphate pulp. The identification markings 5 inside the layer structure are oxidized on the surface of the middle layer 1. The laser marking of the middle layer 1 and its connection to the outer layer 6 covering the markings 5 can take place as shown in Figures 1-3. The second outer layer 8 may be connected to the middle layer 1 even before the marking step or after the steps described in Figs. 1-3.

The embodiment of the invention according to Figure 5 differs from that shown in Figure 4 in that the markings on the board 7 are recesses 5 'formed on the surface of the middle layer 1. If the marking has been made on a board machine while the fibrous material layers 1, 6 are still wet, the recesses 5 'are filled with the material of the outer layer 6 so that the final board 7 is substantially uniform in thickness and density. However, when the materials of the middle and outer layers 1, 6 differ, the markings formed by the recesses 5 'are detectable on the cardboard by means of a detector. In the example case, CTMP is darker than sulphate pulp, which gives the mer-20 markings a lighter light than their surroundings.

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In the schematic figure 6, the identification markings 5 "are points on the middle layer 1 where the material is • exposed to the laser beam over the entire thickness of the layer, e.g., by changing the color or density of the material. The change may be based, for example, on the doping component, such as polymer particles, which are oxidized by the laser beam, or on the dopant component evaporated by the laser beam. Alternatively, only a portion of the layer 1 material thickness could be affected by the laser beam.

It will be apparent to one skilled in the art that the descriptions of the invention are not limited to the foregoing, but may vary within the scope of the following claims.

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Claims (17)

119391 A method for producing identification markings (5) on laminated continuous paper or board (7), characterized in that the markings (5) are applied to a web-like fibrous layer (1) movable by a laser beam (4), after which a second material layer (6) is applied. such that the markings remain within the layer structure (7) of the moving web and that the marked product obtained as a continuous web is wound on a roll. 2. Förfarande enligt patentkrav 1, kännetecknat av, att markeringama (5) glas genome att bräirna fiberskiktets (1) yta. Method according to Claim 1, characterized in that the markings (5) are made by burning the surface of the fiber layer (1). 3. Förfarande enligt patentkrav 1, kännetecknat av, att markeringama (5) or genome att gravera fördjupningar (5 ') i fiberskiktet (1). 4. Förfarande enligt patentkrav 1, kännetecknat av, att fiberskiktet (1) innehäller et dopande ämne som anordnas att reagera eller avdunstas med lasersträlen (4). Method according to claim 1, characterized in that the markings are made by engraving the recesses (5 ') on the fiber layer (1). Method according to Claim 1, characterized in that the fiber layer (1) contains a dopant which is reacted or evaporated by a laser beam (4). 5. Förfarande enligt face av de föregäende patentkraven, kännetecknat av, att efter markingssteg that you supply the rotlikt banlikt fiberskikt (6) leds mot det rörliga fiberskiktet (1). 6. Förfarande enligt patentkrav 5, kännetecknat av, att markeringen sker i en pappers-eller cardboard mask, där fiberskiktet (1) innehäller fuktighet frän memory, banana (7) pricked after sammanfogningssteget av skikten (1,6). Method according to one of the preceding claims, characterized in that, after the marking step, a second movable web-shaped fiber layer (6) is guided against the moving fibrous layer (1). Method according to Claim 5, characterized in that the marking is carried out on a paper or board machine when the fibrous layer (1) contains moisture from the pulp, wherein the web (7) is dried to combine the layers (1, 6). - ·· ♦ After 20 hrs. The method according to claim 6, characterized in that the materials of the fibrous layers (1,6) to be combined differ from one another. • · · · · · · · Förfarande enligt patentkrav 6, kännetecknat av, att materialen av fiberskik-1 (6) som skall sammanfogas, skiljer sig frän varandra. 15 8. Förfarande enligt patentkrav 7, kännetecknat av, att det ena av fiberskikten * · »* som scall moss, bestar av chemisk mass and det andra av mechananisk eller • · · \ · chemimekanisk mass. • · · • · • ·. ···. 9. Förfarande enligt patentkrav 7 eller 8, kännetecknat av, att det ena av fiber- • · "\ m skikten som skall sammanfogas bestär av oblekt mass och det andra av blekt mas- * ::: 20 sa. • · * * · · · A method according to claim 7, characterized in that one of the fiber layers to be combined is a chemical pulp and the other one is a mechanical or chemimetric pulp. • * • «··· A method according to claim 7 or 8, characterized in that the other. one of the fiber layers to be combined is unbleached pulp and the other is bleached * · * pulp. ·· • · • · · · · ·; Method according to one of the preceding claims, characterized in that a coating layer is applied to the marked web-like fibrous layer (1), which obscures the markings (5). 119391 10. Förfarande enligt face av de föregäende patentkraven, kännetecknat av, att for noticing banlika fiberskiktet (1) appliceras et ytbeläggningsskikt som täcker • "* · markeringama (5). * · · • *" "11. Papper eller carton (7) ) med lamellstructur, som kan account mesh med et förfa- 25 rande enligt face av de föregäende patentkraven och som omfattar identifierings - .. \ t markeringar, kännetecknat av, att det banformiga, skin fold pappret eller kar- '*. tongen (7) , omfattar med en lasersträle gjorda markeringar (5) som är infällda i ba- Nans lamellstmktur. 11. Identifiable laminated paper or paperboard (7) obtainable by the method according to any one of the preceding claims, characterized in that the web, rolled paper or paperboard (7) comprises laser beam markings (5) embedded in the layer structure of the web. weather. 12. Papper eller carton enligt patentkrav 11, turnstile roll, att banan är hop-30 rolls kring en Vals eller box. ίο 119391 Paper or board according to claim 11, characterized in that the web is rolled around a roll or core. 13. Cardboard (7) med lamellar structure som kanillverkas med ett förfarande enligt face av patentkraven 1-10 och som omfattar identifieringsmarkingar, tecknad av, att cartonen omfattar med en lasersträle gjorda markeringar (5) som är infällda i en structur som bestär av kartongens fiberskikt (6, 1, 8) at the end of the day. Identifiable laminated board (7) according to any one of claims 1 to 10, characterized in that the board comprises laser beam markings (S) embedded in a structure consisting of overlapping fiber layers of the board (¢ 6.1, 8). . 14. The carton of the patent patent No. 13, the wrapping pattern, the marking of the sticker (5) on the fibers (1), the vibrant framing of the reaction medium of the laser strip. Cardboard according to Claim 13, characterized in that the markings are darkening (5) on the surface of the fiber layer (1) due to the reaction caused by the laser beam. A carton according to claim 13, in which the markings (5 ') are applied to the fibers (1), the material (10) being the quality of the fibers (6). Cardboard according to Claim 13, characterized in that the markings are recesses (5 ') cut into the fiber layer (1) by a laser beam and adjacent · *. ·. · * Filled with fiber material (6) of material of different quality. The carton according to claim 14 or 15, characterized in that one of the fibrous layers is a chemical pulp and the other is a mechanical or chemimechanical 20 pulp. • · · • · · · Cardboard according to one of Claims 13 to 16, characterized in that it is a folding carton consisting of overlapping sulphate and CTMP layers. • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Tong (7) med lamellstruktur som framställs som en fortlöpande hana, kännetecknat av, att markeringama (5) gål med en lasersträle (4) banners fibrilsk · · (1), varefter ett andra materialskikt (6) appliceras access, try to mark ham-nar innanför den rörliga banans lamelstruktur (7), och att den som en fortlöpande 30 bana erhällna markerade produce roll ihop. 119391 16. Cardboard according to claim 14, wherein the fiber-skikten is a mechanical pulp and a detergent mechanical pulp. 17. The carton enligt face av patent craven 13-16, the wrapping nuts av, att det ΜΙ 5 ga om falskartong som bestär av sulfat och CTMP-skikten daily. • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · to · to · back · · • · 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1