Method for processing a board with a wooden surface, and board produced by the method

Abstract

Method for processing a panel (1, 1a, 16) consisting of a carrier panel (3) with at least one surface (5) made of real wood, wherein the following method steps are carried out: • Providing an original material (7); • Optical recording of the material (7) and processing of the recording in a computer system (8) to a digital image file (9); • Providing the plate (1, 1a, 16) and processing the surface (5) before the printing process with a processing machine (4); • Printing the surface (5) with the image file (9) using the lenticular technique, wherein at least one printing layer (17, 18, 19) and at least one lens structure (22, 23) are applied to the surface (5) using at least one printer (10), and that the printing of the processed surface (5) using the lenticular technique is repeated at least twice, thereby resulting in a superposition of several layers.

Description

[0001] The invention relates to a method for processing a board with a wooden surface, as well as a board produced by the method.

[0002] Wood is the most environmentally friendly building material on earth, yet its resources should be used sustainably. To conserve stocks of slow-growing wood species, veneered panel materials are used.

[0003] Veneer is a thin layer of wood that is cut from the trunk using various sawing and cutting processes and then glued to a lower-quality substrate. Substrates can include chipboard, MDF, multiplex boards, or plywood.

[0004] Numerous methods for producing a flat component with a predetermined surface appearance are already known from the prior art. For example, the document DE 103 23 412 A1 already discloses a printing process in which a wooden surface is printed using a printer, whereby the wooden surface is intended to correspond to a predetermined wood species.

[0005] EP 2 292 436 B1 discloses a method for producing a component with a real wood surface using an inkjet printing process. The process described therein gives the surface an appearance that corresponds to a template with a predetermined desired wood species' grain and porosity, as well as a predetermined color. The timber surface approximately corresponds to the porosity of the predetermined desired wood species, and the three-dimensional surface structure of the timber surface is at least partially retained by printing the timber surface using the inkjet printing process.

[0006] EP 2 899 011 A1 discloses a method and device for creating a three-dimensional structure on a surface of an object by means of producing lenticular images. These lenticular images can be created, for example, on an MDF board, a plywood board, or a veneer.

[0007] DE 10 2010 018 225 A1 discloses a method for providing panels, wherein a decoration is applied to the carrier material. The decorations can, for example, also achieve a moving or 3D effect by having the decorative surface with a lenticular lens structure and the decoration with a lenticular print. Furthermore, it is possible to provide the surface of the carrier material with a deep structure adapted to the decoration, for example, a wood grain structure. A chipboard, HDF, MDF, or cork board can be used as the carrier material, for example.

[0008] AT 511 152 A1 discloses a method for producing wooden elements, such as wooden panels, wooden floorboards, or veneers, with a reclaimed wood decor. In this process, the wooden element is cut, planed, and / or edged to the desired dimensions and / or thickness. This is followed by scanning and digitizing the original reclaimed wood surface to capture the desired structure and color. The digital image of the reclaimed wood surface is then printed onto the processed areas of the wooden element's surface, creating a uniform overall impression.

[0009] US 6 424 467 B1 discloses a high-resolution raster lens which has a plurality of lenses on the front surface and a substantially flat back surface onto which an image file is printed using the lenticular technique.

[0010] EP 2 292 435 A2 discloses a method for producing a component with a real wood surface which is printed by means of an inkjet printing process in such a way that its appearance corresponds to that of a template with a grain and porosity corresponding to a predetermined desired type of wood and a predetermined color. US 5 800 907 A describes a method for producing a lens which is designed in such a way that it generates a type of animation when viewed and allows certain images to appear one after the other.

[0011] US 2014 / 0 028 772 A1 describes a method and apparatus for producing a digital image on a surface by applying a layer of powder containing color pigments to the surface, binding a portion of the powder, and removing the unbound powder from the surface.

[0012] JP 2012-254 528 A discloses a method for producing an ornament, wherein a base plate having a smooth surface is printed with two printing layers and a lens structure.

[0013] DE 197 21 192 A1 discloses a biocompatible barrier membrane which preferably consists of titanium, tantalum or another biocompatible metal or a biocompatible metal alloy and has a microperforation.

[0014] The object of the present invention is to provide a method for printing a plate with which a reproducible and distortion-free image representation is achieved.

[0015] To achieve the stated object, the invention is characterized by the technical teaching of patent claim 1.

[0016] An essential feature of the invention is that the wooden surface of the board is treated with various processing techniques to improve its haptics before the actual printing and is then printed using the lenticular technique.

[0017] The lenticular printing process involves the superimposition of multiple layers. This superimposition of multiple images creates a high level of image sharpness, allowing a high depth of field to be achieved even on uneven surfaces.

[0018] Preferably, up to six printing processes take place consecutively or simultaneously. The first layer is white, for example, and the image is then applied gradually. The more printing processes performed, the better the print quality and sharpness of the image. This is a significant advantage of the embodiment according to the invention over the prior art, which, for example, applied the surface in only one printing process.

[0019] Lenticular technology allows wood grain and individual patterns and designs to be created in a continuous process on veneered or pre-coated MDF, HDF and chipboard.

[0020] Preferably, the lenticular technique is used to produce a lens grid image (prism grid image), which creates a three-dimensional (spatial) impression using tiny optical lenses or prisms.

[0021] In the lenticular technique, images, preferably taken from slightly different perspectives, are cut into narrow strips, recombined, and arranged in stripes. The resulting image information is then printed onto the surface of the plate.

[0022] By printing real wood veneer panels using the inventive digital printing technology, the warmth and feel of wood are retained, but the appearance is altered. The combination of different colors, as well as diverse textures and surface treatments, creates a customized product that can be reproduced identically as often as required. Furthermore, the lenticular technique achieves distortion-free printing up to a depth of 3 mm.

[0023] A further advantage of the embodiment according to the invention is that it is now possible to use favorable sortings or qualities of domestic wood species that could not be used previously or could only be used to a limited extent.

[0024] The inkjet printing process is preferably used for the lenticular process. Unlike conventional printing methods such as offset or gravure printing, inkjet printing is a non-contact printing process. Furthermore, inkjet printing does not require a fixed printing form, meaning different information, such as variable graphics or fonts, can be printed one after the other.

[0025] Printing with the lenticular technique can be carried out, for example, on veneered wood-based panels for flooring, panel or furniture production with a thickness of 0.6 mm, 0.9 mm, 1.5 mm or 2.5 mm.

[0026] Preferably, a real wood surface is applied to a carrier plate, the surface of which can, for example, have the following structures in a subsequent processing process: • rough sawn fine, • rough sawn deep, • rough sawn, coarse, • Planer shaft, • rough relief, • brushed hard, • brushed soft, • brushed abrasive • hacked.

[0027] Surface treatment can be achieved, for example, by brushing or sandblasting. During brushing, rotating brush heads remove the softer wood components from the surface. The hard, resistant components remain, forming a three-dimensional surface that reflects the wood's structure.

[0028] Other preferred surfaces include reclaimed wood, split wood, chopped wood, and brushed surfaces. After finishing the surface, the surface is always dusted with a soft brush or similar tool to remove any dust that may have been created.

[0029] In the method according to the invention, surface treatment takes place with an embossing roller, which imparts a specific structure to the surface. The embossing roller creates a special feel or structure on the surface to be printed. With the help of the embossing roller, haptics can be created on the surface to be printed, which, for example, correspond to a "chopped surface" or a micro-perforated surface. A key advantage of using an embossing roller is that a continuous material can now be embossed in any shape.

[0030] In addition, it is possible to provide the panel with holes such as blind holes, T-holes, hinge holes, hook holes, or fitting holes. The panels can also feature milling, slotting, and CNC machining.

[0031] In a preferred embodiment, the panel has grid holes with different diameters, as well as micro-perforations, so that they can be used as acoustic panels.

[0032] The following boards can be used as carrier boards: plywood, chipboard, blockboard, MDF, HPL compact board, oak carrier board, 3-layer spruce, as well as glass, aluminum materials, composite boards, and much more.

[0033] In a preferred embodiment, precious wood sheets are selected and joined according to the representation, pressed onto a carrier plate and then printed.

[0034] In a preferred embodiment, the first step involves taking a photograph or optically capturing the surface of the original material, for example, in a photo studio. This photograph is then divided into individual layers or strips using a computer system and special software. The original image, which may be 20 MB in size, is then converted into a print template (image file) of up to 3 GB.

[0035] In another preferred embodiment, an ionizer bar, such as a metal rod, is arranged in front of the print head. This bar is guided parallel to the surface to be printed, thereby ionizing the plate. By ionizing the plate, the individual droplets in the inkjet printing process reach precisely the desired point on the plate's surface.

[0036] An additional dust extractor is preferably arranged in front of the metal rod to suck up the dirt or dust particles on the surface to be printed.

[0037] The preferred method for the present invention is an inkjet printer, which is suitable for printing an unlimited number of patterns directly from the computer onto wood panels or similar materials. Inkjet technology is a printing process in which thin ink is sprayed in very small droplets through nozzles onto the surface to be printed. The image is created only on the surface. Since there is no physical contact with the workpiece, printing is possible on both flat and uneven surfaces.

[0038] In a preferred embodiment, a microweave process is used. This is an algorithm for multiple overlays of individual print lines. In conjunction with the variable droplet size, this overlay ensures uniform tonal gradients and a visually rasterless print image. The following line overlays are possible, for example: • 4-Pass Microweave = four-fold line overlay • 8-Pass Microweave = eight-fold line overlay

[0039] The print resolution can be, for example, 720 dpi, unidirectional, 4-pass microweave or 1440 dpi, unidirectional, 8-pass microweave.

[0040] With unidirectional printing, the print head applies ink to the plate surface in only one direction. This significantly increases print quality. Furthermore, printing can also occur in both directions (=bidirectional), which results in a shorter print time but also poorer quality.

[0041] In another preferred embodiment, the surface of the original material is photographed or scanned and interlaced into extremely fine stripes using a digital computer system. The resulting image file is then printed onto the real wood surface, with a transparent grid of vertically arranged cylindrical lenses or prisms placed over the printed layer. Depending on the viewing angle, the lens structure focuses the viewer on a different image strip. The lens strength is determined by the viewing distance. Using the lenticular system, it is possible to display several different images in a single print. The number of phases is determined by the lens size and the image resolution.

[0042] The arrangement of horizontal lenses creates image separation. When the lenses are arranged horizontally, both eyes perceive the same image simultaneously. The arrangement of vertical lenses creates image unification, thus creating a 3D effect. The lenticular stripes and the image information must be arranged vertically for this to happen.

[0043] The following effects can be achieved with the lenticular technique: 2-phase wobbling image, 3- to 5-phase alternating image, animation (video clip), morphing, 3-D images, 3-D images with flip, zoom, unique flip or flyeye.

[0044] By using very narrow semi-cylindrical lenses, the different focusing of the incoming light filters out only the related image elements depending on the viewing angle. Thus, the left eye sees a different image than the right eye. Without special glasses or other aids, the viewer perceives the image as three-dimensional.

[0045] In the embodiment according to the invention, the printing is first carried out on the machined surface and then the lens structure is arranged over it.

[0046] The lens structure consists of a transparent material, such as a toner material, a permeable polymer, a UV-curable material, or a solid-state ink. Of course, the individual materials can also be combined. The key is that each lens structure is aligned to a corresponding group of nested stripes.

[0047] For example, an inkjet printer, a xerographic printer, a dye-jet printer or a laser printer can be used as a printer for the at least one image and / or the lens structure.

[0048] Preferably, the lens structure has several semi-cylindrical convex parts. The more lines per inch (IPI) the lens structure has, the finer the image resolution. For relatively large images, for example, 10 to 60 IPI are required.

[0049] The printing process can be repeated several times, for example, to achieve a suitable height for the lens structure. Furthermore, it is possible to stack multiple lens structures using multiple printing processes.

[0050] Optionally, further processing can be carried out after the printing process, which includes, for example, curing, fixing and / or drying.

[0051] The invention is explained in more detail below with reference to drawings illustrating only one embodiment. Further essential features and advantages of the invention will become apparent from the drawings and their description.

[0052] They show: Fig. 1: Schematic representation of the process step: Production of a special plate surface Fig. 2: Schematic representation of the machined surface Fig. 3: Illustration of the process steps for producing the veneer panel according to the invention Fig. 4: Illustration of the printing process Fig. 5: Representation of the process step: Neutralization of the surface Fig. 6: Illustration of the process step: UV light curing Fig. 7: Schematic diagram: Structure of a non-combustible panel Fig. 8: Schematic representation of the process step: Production of a special plate surface Fig. 9: Illustration of the printing process with a printer Fig. 10: Schematic representation of a plate with a machined surface and a printing layer Fig. 11: Schematic representation of a plate with a machined surface and three superimposed printing layers 11 Fig. 12: Schematic representation of a plate with a machined surface, a printing layer, and a lens structure Fig. 13: Schematic representation of a plate with a machined surface, a printing layer, and several lens structures

[0053] The following figures show different process steps regarding the production and processing of veneered panels.

[0054] With the Fig. 1 shows a first method step in which a veneer panel 1a is processed with a processing machine 4. The veneer panel 1a essentially consists of a carrier panel 3, which has a veneer 2 on its bottom and / or top side. The veneer 2 consists, for example, of a native European wood species produced by sliced veneering, rotary-cutting, sawn veneering, or as sawn timber.

[0055] The surface 5 of the veneer panel 1a is prepared according to the Fig. 1 is processed by a processing machine 4, which is designed as a combined sanding and brushing machine. In particular, the surface 5 is sandblasted and / or brushed in the direction of the grain. Processing with the machine 4 causes the soft annual rings (summer wood) to become more pronounced than the hard annual rings (winter wood), resulting in a sanded but structured surface 5 on the processed veneer panel 1a. The veneer panel 1, 1a can be processed multiple times with the processing machine 4.

[0056] With the Fig. 2 shows the processed veneer panel 1a with its surface 5. The surface 5 now has different contours or a special haptic quality, which can be perceived tactilely.

[0057] The Fig. 3 schematically shows the process steps for producing a veneer panel 1a with digital printing 15 using the process according to the invention.

[0058] In a first step, a digital, high-resolution image of an original material 7 is taken using a camera 6. The original material 7 can be, for example, an aged wooden wall, a concrete wall, a stone wall, a wooden panel with a "vintage look," or the like. The image of the material 7 serves as a template and is later printed onto the surface 5, 5a of the panel 1.

[0059] The image of the material is then processed using a computer system 8, which creates an image file 9 that serves as a template for printing. The digitally processed image file 9 is then printed onto the surface 5 of the veneer panel 1, 1a using the inventive printing process. It is crucial that the printer 9 performs multiple printing operations, with at least three printing operations being necessary. The stripe lens process guarantees a distortion-free representation of the original image, even when the substrate is tactile and uneven.

[0060] Fig. 4 shows the printer 10, which applies a UV-reactive ink to the processed wood surface 5 by means of lenticular printing.

[0061] In order to avoid the microfine color pixels being deflected by static charge before they hit surface 5, the area between surface 5 and pixel nozzles must be neutralized - this is determined by the Fig. 5. In front of the actual print head, an ionizer bar 11 is arranged, which is guided parallel at a distance from the surface 5 to be printed.

[0062] In general, finishing, painting or protective coating can be avoided in most cases, which leads to further resource conservation and high efficiency. Fig. 6 However, it is also possible in a further, optional process step to cure the applied print by irradiation with at least one UV lamp 12.

[0063] With the Fig. Figure 7 shows another preferred embodiment of the panel 16. The material is a non-combustible panel 16, the carrier plate 3 of which consists, for example, of vermiculite (non-combustible A1 according to EN 13501). A thin wood veneer 2 is applied to both sides of the vermiculite carrier plate 3 using a thermosetting adhesive 13.

[0064] According to the Fig. 8, the plate 16 is processed using a special press 14 and subjected to high temperatures. Subsequently, the surface 5 of the plate 16 is ground to a thickness of < 0.2 mm using a processing machine 4, e.g., a grinding machine with an articulated pressure beam.

[0065] Following this ( Fig. 9), an image of the desired original workpiece 7 is applied to the surface 5 of the processed plate 16 using the lenticular technique. A reactive, non-combustible lacquer is then applied using a roller technique in a quantity of <25 g / m2. The final product is then a non-combustible plate 16 with a printed surface.

[0066] With the Fig. 10 shows a printed plate 1, 1a having a machined surface 5, 5a. On the surface 5, 5a is a first printing layer 17, which was created during a printing process with the printer 10. Of course, it is also possible for the first printing layer 17 to extend partially into the surface 5, 5a or to penetrate into the surface 5, 5a.

[0067] Fig. Figure 11 shows a plate 1, 1a, which has a total of three printing layers 17, 18, and 19. The three printing layers 17, 18, and 19 create a special depth effect. In particular, the combination of a machined surface 5, 5a and the three printing layers 17, 18, and 19 results in a surface appearance and feel that corresponds to the original material 7.

[0068] The three printing layers 17, 18, 19 are preferably applied or printed by three successive (repeated) printing processes, resulting in an overlay of the printing layers 17, 18 and 19.

[0069] The key is that, despite a rough or uneven surface 5, 5a, a sharp image with a special depth effect is produced. This is achieved in particular by the multiple printing processes and the multiple printing layers 17, 18, and 19.

[0070] With the Fig. 12 shows a further preferred embodiment, wherein at least one printed layer 17, 18, 19 is applied to the processed surface 5, 5a. At least one lens structure 22 or prism structure 22 is applied over the at least one printed layer 17, 18, 19. The lens structure 22 or prism structure 22 is preferably applied using the same printer 10 that already printed the printed layers 17, 18, or 19 onto the surface 5, 5a. The alignment of the lens structure 22 or prism structure 22 with respect to the printed image of the at least one printed layer 17, 18, 19 is preferably performed by the computer system 8.

[0071] In a further preferred embodiment, it is possible for the computer system 8 to control at least two different printers 10, which successively apply the at least one printing layer 17, 18, 19 and the lens structures 22 or prism structures 22 to the surface 5, 5a. The height 24 of the lens structure 22 is determined by the printing process. In particular, the height 24 of the structures 22, 23 can be influenced by repeating the printing process several times.

[0072] According to the Fig. 13 shows a further preferred embodiment in which at least one further lens structure 23 or prism structure 23 is applied to the first lens structure 22 or prism structure 22. For example, three lens structures 22, 23 or prism structures 22, 23 can be arranged one after the other over the at least one printing layer 17, 18, 19.

[0073] By arranging several lens structures 22, 23 or prism structures 22, 23, the viewing direction 21 is redirected several times, creating a special surface impression. Drawing legend 1 plate, veneer plate 1a 2 veneer 3 Carrier plate 4 processing machine 5 surface, 5a surface machined 6 Camera 7 Material (original) 8 IT (System) 9 Image file 10 printers 11 ionizer bar 12 UV lamp 13 Adhesive 14 Press 15 Digital printing 16 plates 17 1st printing layer 18 2nd printing layer 19 3rd printing layer 20 Eye 21 Direction of view 22 lens structure / prism structure (1st layer) 23 lens structure / prism structure (2nd layer) 24 Height of lenses 22, 23

Claims

[1] Method for processing a panel (1, 1a, 16) which consists of a carrier panel (3) with at least one surface (5) made of real wood, wherein the following method steps are carried out: • Providing an original material (7); • Optical recording of the material (7) and processing of the recording in a computer system (8) to a digital image file (9); • Providing the plate (1, 1a, 16) and processing the surface (5) before the printing process with a processing machine (4); • Printing the surface (5) with the image file (9) using the lenticular technique, wherein at least one printing layer (17, 18, 19) and at least one lens structure (22, 23) are applied to the surface (5) using at least one printer (10), and that the printing of the processed surface (5) using the lenticular technique is repeated at least twice, thereby resulting in a superposition of several layers. [2] Method according to claim 1, characterized by that the plate (1, 1a, 16) has grid holes with different diameters, as well as micro-perforations, so that the plate (1, 1a, 16) can be used as an acoustic plate. [3] Method according to claim 1, characterized by that the processing machine (4) sandblasts and / or brushes the surface (5). [4] Method according to claim 1, characterized by that the processing machine (4) processes the surface (5) by means of an embossing roller. [5] Method according to claim 1, characterized by that the processing machine (4) drills holes, millings or slots into the surface (5). [6] Method according to one of claims 1 to 5, characterized by that the printer (10) prints a lens structure (22, 23) with a toner material, a permeable polymer, a UV-curable material or a solid phase ink. [7] Method according to one of claims 1 to 6, characterized by that after the printing process, a UV varnish or a UV oil is applied to the surface (5, 5a) of the plate (1) and after the printing process, the surface (5, 5a) is irradiated with at least one UV light. [8] Method according to one of claims 1 to 7, characterized by that the optical recording of the surface (5) of the original material (7) takes place from slightly offset perspectives and the image material (recording) is processed in the so-called interlacing process with the aid of an EDP system (8) and special software which digitally divides the image material (9) into fine strips, whereby an alignment of the strips and the lens structure (22, 23) takes place with the EDP system (8). [9] Method according to one of claims 1 to 8, characterized by that after the printing process, a reactive, non-flammable varnish is applied using a rolling technique. [10] Method according to one of claims 1 to 9, characterized bythat the surface (5) of the plate (1,1a, 16) is covered with at least one primer film which is printed using the lenticular technique. [11] Board (1, 1a, 16) consisting of a carrier board (3) and at least one surface (5, 5a) made of real wood, wherein the surface (5, 5a) has a tactile structure due to mechanical processing and the surface (5, 5a) is printable with at least one printing layer (17, 18, 19), characterized by that the plate (1, 1a, 16) is produced by a method according to claims 1 to 10. [12] Plate (1,1a,16) according to claim 11, characterized by that the carrier plate (3) is made of non-combustible vermiculite.

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