Method and system for creating a pattern on a substrate

Abstract

A method and system for producing a pattern (7) on a substrate (1; 4), the method comprising successively: providing a base layer (2) at least partially covering the substrate (1; 4); applying a plurality of liquid droplets in or on the base layer (2), and transferring at least a portion of the liquid (3) comprising or at least partially defined by the liquid droplets to a transfer surface (S) by means of adhesion of the liquid (3) to the transfer surface (S) when the transfer surface (S) is in contact with the liquid (3) without the transfer surface (S) sliding on the base layer (2), so as to at least partially reveal the pattern (7).

Description

Technical Field

[0001] The present invention relates to a method and system for producing patterns such as embossing or texture on a substrate, wherein a plurality of droplets with defined patterns are applied, for example by means of digital inkjet printing, on a base layer extending on the surface of the substrate.

[0002] This invention is particularly applicable to the field of manufacturing products for building and furniture, such as panels for furniture, doors and floors, and profiles for door and window frames. Background Technology

[0003] Currently, methods and systems for creating patterns on substrates by applying multiple droplets (e.g., by means of digital inkjet printing) to a base layer extending on the surface of a substrate are well known. These methods and systems offer advantages in terms of high flexibility and high precision compared to other methods and systems for creating patterns on substrates, such as engraving or molding.

[0004] For example, document US2010 / 092688 discloses a method for creating an embossing on a substrate by means of digital inkjet printing on a liquid base layer extending on the substrate. The droplets and the liquid base layer are configured to be immiscible with each other, such that the injected droplets repel the liquid surface of the base layer on which they are applied and are introduced into the base layer so that an embossing is generated once the base layer has solidified.

[0005] Similarly, document WO2010070485A2 discloses a method and system for producing embossing on a substrate by means of digital inkjet printing on a liquid base layer extending on the substrate. The droplets are configured to provide a masking effect relative to the liquid base layer, thereby inhibiting solidification of the liquid base layer at the location where the droplets are applied by blocking curing or heating radiation from penetrating to the liquid base layer. Once the base layer has solidified, the material beneath the droplets (whose solidification has been inhibited) is soft or partially solidified, making it easily removable from the base layer to produce the embossing. Devices such as brushes or vacuum devices are mentioned for removing the material and droplets.

[0006] Similarly, document WO2011126148A1 discloses a method for creating embossing on a substrate by means of digital inkjet printing on a liquid substrate extending on the substrate. Due to the impact force or amount of movement of the droplets when they impact the liquid substrate, the viscosity and / or surface tension of the droplets and the liquid substrate, the droplets injected on the liquid substrate create negative embossing in the substrate.

[0007] Similarly, document WO2020039361A1 discloses a method and system for producing embossing on a substrate by means of digital inkjet printing on a liquid base layer extending on the substrate. The droplets and the base layer are solidified, for example by UV curing, and the droplets are configured to inhibit or modify solidification, for example by a curing inhibitor, such as a UV absorber, so that the area of ​​the base layer to which the droplets have been applied is softer or more brittle than the rest of the base layer. Therefore, the resulting product corresponding to the mixture of droplets and base layer in said area can be easily removed from the base layer to produce the embossing. Means such as brushing, air or water jetting, tape or adhesive rollers, or solvents are mentioned for removing said product.

[0008] Known means for removing the resulting product (which, in the context of this invention, is generally understood to include or be at least partially defined by the applied droplets) have the disadvantage that they cause the obtained pattern to lose sharpness or clarity due to the abrasion that may be required to remove sufficient resulting product. Removal of the resulting product is performed by dragging force, or in a manner that allows the product to be removed, extracted, or separated from the substrate by means of a movement of the product or a fluid element.

[0009] Besides requiring the product generated by the applied droplets to be solid for removal, using adhesive rollers or tapes (i.e., with adhesive provided) has the disadvantage that they easily soil the substrate surface, leaving adhesive residue adhering to the substrate, thus requiring additional steps to remove the adhesive from the substrate surface. Since abrasion may be needed to remove or separate the adhesive, this again easily leads to a loss of sharpness or clarity in the obtained pattern. Furthermore, the use of solvents also has the disadvantage of potentially causing degradation on the substrate surface due to the solvent itself.

[0010] Removing the product generated by the applied droplets through heating, evaporation, or drying is also known in the prior art. Alternatively or complementaryly, traces of the product can be retained solidified, particularly cured, especially along with the substrate on the resulting pattern.

[0011] The means of removing the resulting product by heating, drying or evaporation have the disadvantage that they may not be able to effectively remove enough product to obtain a specific pattern, such as a relief with at least a certain depth.

[0012] In addition, known means of removing the resulting products have the disadvantage of being difficult to clean or maintain, because when the products are removed, they accumulate in the device, for example, in the bristles of a brush, or spread in an unpredictable or uncontrolled manner.

[0013] In view of the known solutions currently available, the present invention aims to provide an alternative or complementary method and system for generating patterns on a substrate, which enables the overcoming of the aforementioned disadvantages. Summary of the Invention

[0014] The purpose of this invention In order to achieve the objectives mentioned in the preceding section, in addition to providing additional advantages that can be derived from this specification, the present invention provides a method for generating a pattern on a substrate, the method comprising: providing a base layer that at least partially covers the substrate; applying a plurality of droplets in or on the base layer; and transferring a portion of a liquid comprising the droplets or at least partially defined by the droplets to the transfer surface, by adhering the liquid to the transfer surface, so as to at least partially reveal the pattern, while the transfer surface is in contact with the liquid without sliding on the base layer.

[0015] In the context of this invention, "pattern" can be particularly understood as decoration or relief. Relief can particularly be understood as a three-dimensional surface or texture. Patterns can be decorative or functional. Examples of decorative patterns are matte finishes or textures that mimic natural surfaces such as rock or wood. Examples of functional patterns are patterns used to modify the physical properties of a substrate, such as elasticity, adhesion, strength, surface roughness, and its optical or tactile properties. Microstructural functional patterns can be used in fields such as biology, optics, and electronics. For example, they are used in optics to produce Fresnel lenses; in electronics to produce circuits, particularly microfluidic channels; and in biology to produce pharmaceuticals.

[0016] The relief obtained by applying this method can be positive (raised on the substrate) or negative (grooved in the substrate). The pattern can also consist of, for example, so-called reverse printing, where a previously applied background is made visible by removing the transfer liquid from the substrate. Reverse printing advantageously allows decoration to be achieved using inks that, due to their characteristics, cannot be printed by inkjet printing (e.g., inks with solid particles, particularly those containing metal particles), by applying the ink onto a background that becomes visible after this method.

[0017] According to the invention, when the resulting liquid contacts the transfer surface and the transfer surface does not slide on the substrate, the transfer of the liquid generated by the applied droplets to the transfer surface is performed by adhesion, i.e., particularly by wetting the surface. The transfer of the liquid occurs through the action of intermolecular forces, such as van der Waals forces. According to the invention, when the transfer surface and the liquid are in contact with each other and the transfer surface does not slide on the substrate, these intermolecular forces act between the transfer surface and the liquid, and thus prevent a tangential drag component of the liquid from the substrate. By preventing this tangential component, the invention makes it possible to remove the product (liquid) generated by the applied droplets without significant deformation or localized tangential movement of the product during contact, thereby preventing the product from slipping on the substrate when the pattern is developed, and thus preventing defects in the sharpness or clarity of the obtained pattern.

[0018] When the resulting liquid comes into contact with the transfer surface, the transfer of liquid generated by the droplets applied to the transfer surface is performed, the transfer surface being either facing the surface of the substrate or opposite the surface of the substrate.

[0019] The transfer surface can be the rolling surface of the transfer roller. The rolling of the transfer roller on the substrate is performed without slippage. For this purpose, preferably, the rotation of the transfer roller is actuated, particularly in a manner synchronized with the transfer of the substrate; in other words, the linear velocity of the rolling surface (transfer surface) relative to the substrate when in contact with the substrate is essentially zero. When the transfer roller rolls without slipping on the substrate, the relative velocity of the rolling surface relative to the substrate is zero, the transfer is performed locally in a static manner, and thus pattern defects caused by slippage of the transfer liquid relative to the application position of the droplets are prevented.

[0020] According to the invention, in order to come into contact with the transfer liquid, the transfer surface can be any surface facing or away from the substrate or base layer. For example, it can also be the front surface of a transfer sheet facing the substrate. Similarly, it is also envisioned that, instead of a transfer roller or transfer sheet (continuous or discontinuous) as a transfer element, any other element included in the transfer surface, such as a plate having a front surface (transfer surface) facing the substrate, can be used.

[0021] The base layer extends at least partially on the surface of the substrate. Liquid base layers can be applied, for example by means of rollers, spraying, or printing, particularly by inkjet printing.

[0022] A droplet is applied to or onto a substrate, particularly a substrate at least partially composed of liquid, such that the applied droplet settles at the location of application into, is introduced into, and / or displaces the liquid substrate. A pattern is formed in or onto the substrate, particularly by at least partially, and more particularly completely, removing the transferred liquid, and is at least partially revealed on the substrate. In particular, a relief can be formed in the substrate when the volume occupied by the transferred liquid in the substrate is released.

[0023] By modifying the composition of the droplets and / or the liquid substrate, for example, to obtain a certain viscosity, density, or surface tension of the liquid when the droplets are applied, and by modifying the parameters of the method of applying the droplets to or onto the liquid substrate (such as, for example, the injection rate or injection volume of the droplets, and / or other parameters of the method), it is possible to control or influence the pattern to be obtained, such that the applied droplets settle into, are introduced into, and / or displace the liquid substrate at the location where they are applied. Therefore, the actual content of the disclosure referenced in the Prior Art section is incorporated herein by reference, provided that it applies to the method and system for generating patterns on a substrate according to the invention.

[0024] Other parameters of the method that can be modified to obtain the desired pattern include, for example, the degree of solidification or curing of the droplets, the transfer liquid, and / or the substrate, the pressure applied to the transfer surface, or the height at which the transfer surface is positioned on the substrate surface when the transfer liquid is transferred. The degree of solidification, particularly the degree of curing, of the substrate, droplets, or transfer liquid can be determined by means of the amount of transfer energy relative to the total energy transferred until solidification is complete, for example by radiation or by heating.

[0025] In particular, it is envisioned that in order to increase the adhesion or wettability of the transfer liquid and / or reduce the adhesion or wettability of the substrate to / on the transfer surface, at least one parameter of the liquid substrate, the droplet and / or the viscosity and / or surface tension of the transfer liquid when the droplet is applied, and / or the method is selected such that the surface energy of the transfer surface is preferably greater than the surface tension of the liquid to be transferred and / or less than or equal to the surface tension or surface energy of the substrate when the liquid is transferred.

[0026] Similarly, for the same purpose mentioned in the previous paragraph, it is envisioned that the viscosity and / or surface tension of the liquid substrate, droplets, and / or the transfer liquid when the droplets are applied, and / or at least one parameter of the method, are selected such that the viscosity of the transfer liquid is preferably less than the viscosity of the substrate when the liquid is transferred.

[0027] In particular, the transfer liquid has a lower viscosity and lower surface tension compared to the substrate, while the surface tension or surface energy of the transfer surface is higher than that of the transfer liquid when the liquid is transferred. This facilitates the transfer of the liquid to the transfer surface via adhesion due to the intermolecular forces between the liquid and the transfer surface. Furthermore, by increasing the viscosity of the transfer liquid when it is transferred, the cohesive force of the transfer liquid can be increased due to the internal intermolecular forces, and therefore it is possible to influence the amount of liquid removed in each transfer by modifying the viscosity.

[0028] Preferably, the surface tension and / or viscosity of the transfer liquid should be low enough during its transfer to facilitate wetting of the transfer surface. Similarly, preferably, the surface tension and / or viscosity of the substrate should be high enough to prevent the substrate from wetting the transfer surface when the transfer liquid is removed.

[0029] Preferably, according to the invention, the substrate is at least partially solidified before the transfer liquid is transferred by means of the transfer surface, until the surface tension or surface energy of the substrate reaches a level greater than or equal to the surface energy of the transfer surface.

[0030] The solidification of the substrate, the applied droplets, and / or the transferred liquid can be performed, for example, by curing, particularly by radiation, more particularly by electromagnetic radiation, and preferably by UV. In the context of this invention, the term curing includes the concept of polymerization. Alternatively or complementaryly, solidification can be performed, for example, by heating, drying, and / or evaporation.

[0031] Preferably, droplets are applied selectively, more particularly according to the pattern, such as a digital pattern, especially by means of digital printing, preferably by inkjet. In particular, the digital pattern is aligned with the image on the substrate, such that the pattern (e.g., embossing) is synchronized with the image in at least one area of ​​the substrate. In this way, it is possible to mimic natural colors or textures (e.g., wood or rock), including grain or cracks, in a more realistic manner.

[0032] According to the invention, the transfer liquid is at least partially determined by, or comprises, the applied droplets. In other words, at least a portion of the transfer liquid may be generated by physical and / or chemical changes in the applied droplets themselves and / or by their interaction with the substrate, particularly by chemical reactions, mixing, or immiscibility between the applied droplets and the substrate.

[0033] Preferably, the droplets and / or transfer liquid can be configured to counteract or inhibit the solidification of the substrate. Specifically, the droplets and / or transfer liquid can be configured to solidify to a lesser extent than the substrate; in other words, such that, for example, when the substrate is completely solidified, the droplets and / or transfer liquid partially solidify. For example, it is possible to counteract solidification by using droplets or transfer liquids of a non-curable material (such as, for example, water). Similarly, it is possible, for example, to inhibit solidification by means of a UV absorber during UV curing.

[0034] The substrate, particularly the liquid substrate, can be made of, for example, a UV-polymerizable resin, especially acrylic or acrylate resin. The droplet can further comprise a UV-polymerizable resin, particularly acrylic or acrylate resin. The droplet may be provided with a curing inhibitor, for example, configured to partially absorb electromagnetic radiation, particularly compared to the substrate. Examples of UV curing inhibitors are benzophenone, benzotriazole, hindered amines, and / or oxalamide. Similarly, the droplet may be provided with a surface tension increaser, such as, for example, a surfactant. Likewise, the droplet may be provided with a viscosity reducer, such as, for example, water, and / or a solvent, such as alcohol or ethylene glycol.

[0035] Preferably, the transfer liquid is at least partially removed by means of a transfer surface before and / or after the substrate has at least partially solidified. The applied droplets and / or transfer liquid can at least partially solidify, particularly together with the substrate. In other words, the substrate, droplets, and / or transfer liquid can be configured to solidify in this manner, particularly to be curable.

[0036] It is also envisioned that the liquid substrate can be at least partially solidified before the droplets are applied. This allows the parameters for obtaining a specific pattern by applying the droplets to be controlled, particularly the viscosity and / or surface tension of the substrate, the droplets, and / or the transfer liquid.

[0037] The transfer surface can be configured to apply adjustable pressure to the substrate and / or be brought closer to the substrate so as to be positioned at a certain height relative to the substrate surface. For this purpose, the height of the transfer surface relative to the substrate surface can be adjusted. Decreasing the height allows for greater pressure to be applied to the substrate, and vice versa. Similarly, height adjustment specifically allows the method to accommodate different thicknesses of liquid substrates and / or base layers.

[0038] In addition to devices for displacing the transfer surface in height, for example by means of a linear actuator, it is envisioned to use auxiliary pressure devices, including, for example, reverse pressure elements, such as rollers.

[0039] The present invention envisions the use of multiple transfer surfaces. In this way, it is possible to gradually remove the transfer liquid by means of successive transfer surfaces. Successive transfer surfaces can be understood as transfer surfaces that are applied successively in the method (successive transfer steps), and particularly transfer surfaces arranged successively in a system for generating patterns according to the method.

[0040] The substrate can at least partially solidify between successive applications. In other words, in this method, the substrate solidifies at the time intervals between the successive applications of the transfer surfaces, particularly in systems used to generate patterns according to this method, where the solidification device is arranged between the successive transfer surfaces. It is also envisioned that the pressure applied by the transfer surfaces (or by different transfer surfaces) increases successively, and / or the height of the transfer surfaces relative to the substrate surface decreases successively. In particular, the pressure applied to the substrate by the subsequent successive transfer surfaces is greater than the pressure applied to the substrate by the previous successive transfer surfaces. In this way, as the method proceeds, it helps to remove the transfer liquid located at greater depths.

[0041] Preferably, according to the invention, the transfer surface is cleaned to remove products generated by the removed transfer liquid. In this way, continuous cleaning of the transfer liquid is facilitated, unlike prior art cleaning systems in which products generated by the applied droplets diffuse more or less around their removal area, thus requiring auxiliary cleaning systems such as suction devices.

[0042] Preferably, the transfer surface is solid. In particular, the transfer surface is at least partially free of liquid. Preferably, the transfer surface is at least partially free of adhesive. Adhesive can be understood as a substance used to bond solids, such as glue.

[0043] Preferably, the transfer surface is shaped such that it substantially replicates the surface of the substrate when it comes into contact with the transfer liquid. In particular, for substrates in the form of panels or sheets, the transfer surface is substantially flat, or the curvature of the transfer surface is substantially the same as the curvature of the substrate or base layer. It is also preferred that the transfer surface extends at least to the entire width of the substrate.

[0044] The envisioned transfer surface is substantially smooth. A substantially smooth transfer surface can be understood as having a surface roughness of less than or equal to 2 μm, and more specifically, less than or equal to 1 μm (Ra, measured according to ISO standard 4288:1998). In this way, it facilitates the cleaning of the transfer surface.

[0045] However, to increase the wettability of the transfer surface, a sufficiently high roughness can be provided, particularly greater than 2 μm (Ra, measured according to ISO standard 4288:1998), for example, by scribing the transfer surface. Preferably, the roughness is less than or equal to 50 μm, more preferably less than or equal to 15 μm (Ra, measured according to ISO standard 4288:1998), which allows the wettability of the transfer surface to be increased without significantly hindering its cleaning.

[0046] It is also envisioned that the transfer surface is essentially deformable. An essentially deformable surface can be understood as one that is adaptable to the relief obtained in the substrate by means of this method, essentially in contact with the substrate surface that forms the relief.

[0047] According to the present invention, patterns with reliefs or textures that mimic natural materials, such as rock or wood, including textures or cracks, can be obtained. Preferably, for a substrate with a thickness up to 500 μm, particularly from 50 to 200 μm, a relief with a depth equal to the substrate thickness can be obtained, particularly from 1 to 500 μm, more particularly from 2 to 200 μm, and even more particularly from 3 to 50 μm. By using a substantially soft material for the rolling surface, such as rubber, and especially EPDM (ethylene propylene diene), a substantially deformable transfer surface can be obtained. For the purposes of this invention, substantially soft can be understood as having a Shore A hardness (Shore A grade) less than or equal to 50, preferably less than or equal to 30, as measured according to ISO 7619-1:2011.

[0048] Alternatively or complementary, considering that a high surface energy or surface tension of the rolling surface is beneficial to its wettability or vice versa, the material of the transfer surface can be selected to have a suitable surface energy or surface tension based on the required amount of transfer liquid to be removed relative to the substrate. In this sense, for example, the use of porous or low-density materials is beneficial for the absorption of transfer liquid due to the effects of surface tension or capillary action.

[0049] In order to achieve the objectives mentioned in the prior art section, in addition to providing additional advantages that can be obtained from this specification, the present invention also provides a system, particularly an apparatus or machine, configured to generate a pattern on the surface of a substrate by performing the method of the present invention as described above.

[0050] The system according to the invention includes a substrate transport device for transporting a substrate having a base layer and a droplet application device for applying droplets into or onto the base layer. The system is characterized in that it further includes at least one transfer element provided with a transfer surface for transferring the liquid to the transfer surface when the transfer surface comes into contact with the liquid, the transfer element being configured such that the contact does not slide on the base layer in a manner synchronized with the substrate transport.

[0051] In particular, synchronization can be performed while the substrate is being transported or held stationary. For example, if the transfer element is in the form of a transfer roller that rolls on the substrate without slipping, the relative velocity of the roller in contact with the substrate relative to the substrate is zero. Similarly, for example, if the transfer element is in the form of a sheet or plate in contact with the substrate, the relative velocity of the sheet or plate relative to the substrate is zero in the direction corresponding to the transport of the substrate.

[0052] The transport device may include a conveyor belt. The application device may include at least one digital printhead, particularly an inkjet printhead.

[0053] Furthermore, the system may include a coagulation device for solidifying the substrate, droplets, and / or transferring liquids. The coagulation device may include a curing apparatus, particularly a radiation source, more particularly electromagnetic radiation, preferably UV radiation. Electromagnetic radiation curing apparatuses may have variable wavelengths.

[0054] The system may also include means for applying a substrate (particularly a liquid), means for pressing against the transfer surface and / or displacing the transfer surface in height relative to the substrate, means for cleaning products generated by the removed transfer liquid, etc. Preferably, the system includes control means configured to perform the method. Attached Figure Description

[0055] The following figures illustrate different practical embodiments of the invention, which are described below by way of example rather than limitation.

[0056] Figure 1 A first embodiment of the method and system for generating patterns according to the present invention is schematically shown, wherein the substrate used is in the form of a panel.

[0057] Figure 2 A second embodiment of the method and system for generating patterns according to the present invention is illustrated schematically, wherein the substrate used is in the form of a sheet.

[0058] Figure 3 An embodiment of transfer by means of a roller-shaped transfer element according to the invention is illustrated schematically, applicable to the first embodiment.

[0059] Figure 4 An additional embodiment of transfer by means of a roller-shaped transfer element according to the invention is illustrated schematically, which is applicable to the second embodiment.

[0060] Figures 5 to 8 A corresponding additional embodiment of the invention, which involves transfer by means of a transfer element in the form of a continuous sheet, is schematically shown and is applicable to both the first and second embodiments.

[0061] Figures 9a to 9d A third embodiment of the method and system for generating patterns according to the present invention is illustrated schematically, wherein the transfer is performed while the substrate is held fixed, unlike the first and second embodiments, in which the transfer is performed while the substrate is being transported in the system. This transfer is performed by means of a transfer element in the form of a plate.

[0062] Figure 10 and 11 A corresponding additional embodiment of the invention, which involves transfer by means of a transfer element in the form of a continuous sheet, is schematically shown and is applicable to any of the first to third embodiments.

[0063] Figures 12a to 12c Figures 13a to 13e schematically illustrate different embodiments of the liquid-cleaning apparatus, each of which can be used independently or in combination with the embodiments in the foregoing figures.

[0064] also, Figure 13c and 13d Different embodiments of the auxiliary cleaning device are schematically illustrated, and Figure 13e Embodiments of devices for reusing cleaning products are schematically illustrated, particularly devices for recycling cleaning products. Each of these additional embodiments can be applied independently to the embodiments in the preceding figures or in combination with the embodiments in the preceding figures.

[0065] Figure 14 A digital pattern corresponding to a local area of ​​an embossed design, obtained according to an exemplary embodiment of the present invention, is shown.

[0066] Figure 15a , 16a 17a illustrates the invention based on Figure 14 The digital pattern shown is a photograph of the relief sculpture.

[0067] Figure 15b , 16b Figures 17b show photographs of reliefs obtained according to a comparative method of the prior art, wherein the removal of the transfer liquid is carried out by means of brushing rather than by means of a transfer roller as in the present invention.

[0068] Figure 18 The representation is shown based on the corresponding Figure 14 , 15a Graphs of parameters of the methods and systems of variations of the present invention, 16a and 17a. Detailed Implementation

[0069] Figure 1 A schematic side view of a first embodiment of the system according to the invention is shown, wherein the base (1) is in the form of a panel. In the figures, the base (1) can be transported forward in a left-to-right direction through different stations of the system when the steps of the corresponding method are performed. To move the base (1), a transport device (60) is used, which includes, for example, a conveyor belt (63) or a conveyor roller in a manner known per se.

[0070] exist Figure 1In the first station of the system shown, a liquid base layer (2) is applied to the substrate (1) by means of a liquid base layer application device (20). In the embodiment shown, the liquid base layer application device (20) is used for application by means of a roller, which includes an applicator roller (21) and a metering roller (22) in a manner known per se.

[0071] As in Figure 1 As seen in the diagram, droplets are then applied to the liquid substrate (2) by means of a droplet application device (30). In the illustrated embodiment, the droplet application device (30) is used for digital printing and includes at least one inkjet printhead (31), each printhead (31) including multiple droplet nozzles corresponding to different positions or pixels, wherein droplets are applied in a manner known per se to produce a pattern (7), in which case the pattern is in the form of an emboss or texture. The pattern (7) is revealed by removing the liquid (3).

[0072] In particular, due to the characteristics of the substrate (2) and / or the droplets (such as viscosity, surface tension or surface energy and density) and the droplet application parameters (such as droplet injection velocity and injection volume), the applied droplets settle, are introduced into the liquid substrate (2) and / or displace the liquid substrate (2) in a manner known per se at the location where the droplets are applied. Modification of these characteristics or parameters makes it possible to control the characteristics of the pattern (7) to be obtained, especially the forces affecting the hydrodynamics between the droplets and the substrate, particularly by changing the amount of droplet movement when the droplets are deposited on or impact the surface of the liquid substrate (2) and the intermolecular adhesion and / or cohesive forces.

[0073] According to the method or system of the invention, a pattern (7) is obtained on the substrate (1) by removing the liquid (3) generated by the applied droplets through transfer from the substrate (2); in other words, it is at least partially defined by, or at least partially comprised of, the applied droplets. Depending on how the pattern (7) is obtained, the transferred liquid (3) may, for example, consist only of the liquid from the applied droplets, or may consist of a mixture of the liquid from the applied droplets and the liquid from the liquid substrate (2) at the location where the droplets were applied. Different ways of obtaining a pattern by removing the liquid (3) generated by the applied droplets are known; all of them can be applied to the invention.

[0074] continue Figure 1In one embodiment, once the transfer liquid (3) has formed in the substrate (2), a substrate curing device (40) is applied. In the illustrated embodiment, the substrate curing device (40) is cured by UV radiation from at least one initial UV curing lamp (41), which is applied to the substrate (1) and the components of the transfer liquid (3). Using these initial UV curing lamps (41), partial curing is provided to the substrate (2), which will allow the transfer liquid (3) to be removed, particularly without removing the substrate (2), in subsequent steps of the method or at a station of the system, by transferring the liquid (3) to the transfer surface (S), particularly by means of at least one transfer roller (10, 11, 12, 13) according to the invention.

[0075] exist Figure 1 In the illustrated embodiment, three successive transfer rollers (11, 12, 13) are used, which are configured to gradually remove the transfer liquid (3) as they roll on the substrate (2). For this purpose, each subsequent successive transfer roller applies increasing pressure to the substrate (2) through its respective rolling surface (S) (i.e., the transfer surface (S), with the rollers (11, 12, 13) arranged at a gradually decreasing height relative to the substrate (1). According to the invention, the liquid (3) is removed by means of the transfer rollers (11, 12, 13) and rolled on the substrate (2) through the rolling surface (S), such that the transfer liquid (3) is transferred to the rolling surface (S) by adhering to or wetting the rolling surface (S) with the liquid (3).

[0076] for Figure 1 Each transfer roller (11, 12, 13) shown in the embodiments is provided with a transfer liquid cleaning device (50), which may be in the form of a blade (51) and is configured to clean the liquid (3) transferred from the rolling surface (S) by scraping the rolling surface (S) with the blade (51).

[0077] Finally, the base coagulation device (40) is applied in... Figure 1 In the illustrated embodiment, the device performs UV curing by means of at least one final UV curing lamp (42). Using these final UV curing lamps (42), the substrate (2) is provided with complete curing until the pattern (7) is obtained.

[0078] Figure 2 A schematic side view of a second embodiment of the system according to the invention is shown, wherein, unlike the first embodiment, the substrate (4) is in the form of a continuous sheet. When the steps of the corresponding method are performed, the substrate (4) is continuously fed through different stations of the system. Once the pattern (7) has been formed in the substrate (4), the substrate (4) is fed from the feed reel (5) and collected in the collection reel (6).

[0079] Advantageously, the invention can be applied to substrates (1; 4) having any form or construction. In particular, the method can be applied to substrates (4) in sheet form (continuous or discontinuous), unlike prior art methods, in which abrasive forces that must be applied to the substrate (2) to remove liquids or products generated by applied droplets, for example by brushing, prevent them from being applied to substrates (4) with low mechanical resistance to shear stress, such as continuous sheets, because the sheets tend to break due to said forces.

[0080] Unlike existing technologies, according to the present invention, the removal of liquid (3) generated by the applied droplets is performed by transferring it from the substrate to the transfer surface, essentially by means of intermolecular forces, i.e., in a static or predominantly static or quasi-static manner. In this way, it is possible to advantageously remove the products generated by the applied droplets in order to create patterns applied to a substrate with low resistance to shear stress, such as thinner sheets.

[0081] Similar to Figure 1 The first embodiment shown is in Figure 2 In the second embodiment shown, the liquid base layer (2) is first applied to the surface of the substrate (4) by means of a base layer application device (20) by a roller comprising an applicator roller (21) and a metering roller (22). Then, droplets are applied by means of an inkjet droplet application device (30) comprising at least one inkjet printhead (31) such that the droplets define the transfer liquid (3) in the base layer (2).

[0082] Similarly, according to Figure 2 The system of the second embodiment shown includes a substrate curing device (40) cured by electromagnetic radiation, which is formed by an initial UV curing lamp (41) and a final UV curing lamp (42). Unlike the first embodiment, this second embodiment incorporates a single transfer roller (10) with a corresponding transfer liquid cleaning device (50), which includes a cleaning blade (51).

[0083] continue Figure 2 The transfer device (60) for the substrate (4) may include guide rollers (not shown) for the substrate (4) in a manner known per se. Similarly, in the application area and / or solidification area of ​​the droplets, the system may incorporate a substrate positioning device to prevent unwanted displacement of the substrate (1; 4) and thus prevent printing and / or solidification defects. The substrate (1; 4) may, for example, take the form of a suction chamber for the substrate in a manner known per se. These devices for preventing unwanted displacement are also applicable in a manner known per se, particularly to the first embodiment involving a substrate (1) in the form of a panel.

[0084] Figure 3A schematic side view of an embodiment of a transfer liquid removal device (3) according to the present invention is shown, which is suitable for, for example... Figure 1 The first embodiment shown can be combined with the remaining embodiments described.

[0085] As in Figure 3 As seen in more detail, the system includes a transfer roller actuator (14) for rotating the transfer roller (10) as it rolls on the base layer (2) by means of the rolling surface (S) of the transfer roller (10). The transfer roller actuator (14) is configured such that the transfer roller (10) can roll on the base layer (2) in sync with the transport of the base layer (1) without slipping.

[0086] If still Figure 3 As seen in the image, the transfer roller (10) is pressed against the base layer (2) with the aid of the reverse roller (10'), which acts on the opposite side of the base layer (1). The system also includes a transfer roller pressure device (70) against the base layer (2), which takes the form of a linear actuator (71) for the height displacement of the transfer roller (10).

[0087] Figure 3 The base transport device (60) is shown in more detail, which includes a conveyor belt (63) guided by at least one conveyor belt guide roller (61, 62) and actuated by a conveyor belt actuator (64).

[0088] Figure 4 A schematic side view of an embodiment of the transfer liquid removal device (3) according to the present invention is shown, which is applicable to, for example... Figure 2 The second embodiment shown can be combined with the remaining embodiments described.

[0089] As in Figure 4 As seen in more detail, the system includes a transfer roller actuator (14) for rotating the transfer roller (10) as it rolls on the base layer (2) by means of the rolling surface (S) of the transfer roller (10). The transfer roller actuator (14) is configured such that the transfer roller (10) can roll on the base layer (2) without slipping.

[0090] Similar to Figure 3 The illustrated embodiment, in Figure 4In one embodiment, the transfer roller (10) is pressed against the substrate (2) with the aid of a reverse roller (10'), which acts on the opposite side of the substrate (4). Similarly, the system also includes a transfer roller pressure device (70) against the substrate, which takes the form of a linear actuator (71) for height displacement of the transfer roller (10). The reverse roller (10') is rotated by the actuator (14') to facilitate guiding the sheet of the substrate (4).

[0091] Figures 5 to 8 A schematic side view of a corresponding additional embodiment of the transfer liquid removal device according to the present invention is shown. These embodiments are applicable to, for example, both the first and second embodiments, and can be combined with each other and with the remainder of the embodiments.

[0092] exist Figure 5 In the illustrated embodiment, unlike the embodiments described above, the transfer surface (S) forms part of the transfer sheet (15) rather than part of the transfer roller (10). The illustrated transfer sheet (15) is continuous; in other words, it is continuously fed from the feed reel (81) to the collection reel (82). According to this… Figure 5 The embodiment shown envisions that the transfer liquid (3) removed from the base layer (2) accumulates in the collection reel (82) for disposal or subsequent processing, which enables it to be reused as a feed reel (81).

[0093] exist Figure 6 In the illustrated embodiment, unlike the embodiments described above, the transfer surface (S) forms part of the transfer sheet (15) rather than part of the transfer roller (10), and furthermore, the transfer sheet (15) is continuously fed in a closed loop; in other words, the transfer sheet (15) is in the form of an annular belt. The transfer sheet (15) is guided in the closed loop by means of guide rollers (83). In this way, a larger usable space is obtained in the system so that auxiliary devices, such as cleaning devices (50; 51) or pressure devices (70; 73), can be installed, for example, by utilizing the space above the pressure roller (72). Figure 6 As shown.

[0094] exist Figure 7 In the illustrated embodiment, the transfer sheet (15) is continuously fed in a closed loop by a plurality of guide rollers (in this case, two guide rollers (83)) and a plurality of pressure rollers (72) (in this case, two successive pressure rollers (72)). Advantageously, as Figure 7As shown, a base layer solidification device (40) can be installed between successive pressure rollers (72). This device may take the form of an electromagnetic radiation curing device, such as at least one UV radiation lamp (43), especially when the transfer sheet (15) is transparent. In this way, the solidification, and in particular the curing, of the base layer (2) or the transfer liquid (3) can be optimized by reducing the amount of air or oxygen between the transfer sheet (15) and the base layer (2), because the transfer sheet (15) remains in contact with the base layer (2) in this area without sliding on the base layer (2), in other words, in conjunction with the forward movement of the substrate (1) in the system.

[0095] replace Figure 7 The guide roller (83) shown is, as Figure 8 As shown, some sliding guide elements (85) can be used, which are made of suitable materials and in shape, in order to reduce friction between the transfer sheet (15) and the sliding element (85). Similarly, instead of the pressure roller (72), some sliding pressure elements (74) can be used.

[0096] Figures 9a to 9d The following steps according to a third embodiment of the invention are shown, wherein the transfer is performed by means of a transfer element in the form of a plate (16), while the substrate (1) remains fixed. Once the transfer element (16) is positioned on the substrate (1) Figure 9a The transfer element (16) descends until it contacts the base layer (2). Figure 9b Next, the transfer element (16) is raised, thereby removing the liquid (3) from the substrate (2). Figure 9c Next, clean (50) the transfer surface (S).

[0097] exist Figure 10 and 11 In the embodiment shown, the transfer element is in the form of a sheet (15). When the substrate (1) is held fixed ( Figure 10 ), or when the substrate (1) is transported ( Figure 11 The transfer surface (S) is pressed against the base layer (2). In the latter case, the transfer sheet (15) is fed without sliding on the base layer (2), in other words, it moves integrally with the base layer (2). Figures 9a to 9d In the embodiment shown in 10, it is envisioned that as the transfer liquid (3) is removed at a deeper depth, the transfer surface (S) can rise and fall successively to contact the transfer liquid (3) on the same surface facing the substrate (2).

[0098] Especially Figures 7 to 11Another advantage of the illustrated embodiment stems from the following feature: the transfer surface (S) is in contact with the transfer liquid (3), and the transfer surface (S) remains facing or opposite to the substrate, particularly between the two pressure application points where the transfer surface (S) abuts against the substrate (2). For example, as Figure 7 , 8 As shown in 10 and 11, the transfer sheet contacts the base layer (2) through a contact surface that extends continuously for a certain length and time between two successive pressure elements (72; 74). Similarly, as Figures 9a to 9d As shown, the front surface of the transfer plate (16) contacts the base layer (2) for a certain length and time. In this way, by increasing the contact time, it is possible to facilitate the adhesion of the transfer liquid (3) to the transfer surface (S).

[0099] Figures 12a to 12c Figures 13a and 13b show schematic side views of embodiments of an apparatus (50) for cleaning products generated by a liquid transferred to a transfer surface (S), which are applicable to embodiments of the invention and are capable of being combined with each other and with the remainder of the embodiments.

[0100] like Figures 12a to 12c As shown, the cleaning device (50) is applied to the rolling surface (S) that forms part of the transfer roller (10), but it can also be applied to the transfer surface (S) that will form part of any other transfer element (e.g., transfer sheet (15) or transfer plate (16)). Figure 13a and 13b In this process, cleaning devices (50) are applied to the transfer surfaces (S) that form part of the transfer sheet (15), but they can also be applied to the rolling surfaces that will form part of any other transfer element.

[0101] Figure 12a A cleaning device (50) in the form of multiple cleaning blades is shown, in this case two successive cleaning blades (51, 52). To facilitate the capture of the transferred liquid (3) by the blades, a cleaning product (56') may be applied, such as a solvent of the product generated by the transferred liquid (3), particularly by means of a cleaning product applicator (56).

[0102] Figure 12bA cleaning device (50) in the form of a cleaning roller (53) is shown, which removes the product generated by the transferred liquid (3) for cleaning by means of a cleaning blade (53'). The outer surface of the cleaning roller (53) can be constructed to be substantially rigid, such as, for example, metallic. In this way, greater resistance to wear of the cleaning roller (53) can be provided compared to a case where the surface is deformable, preventing wear due to contact between the blade and the surface. Similarly, the safety of the system is increased by preventing possible snag between the blade and the roller. A cleaning product collection tank (57) can be arranged for collecting the cleaned product.

[0103] Figure 12c A cleaning device (50) in the form of a cleaning brush (54) is shown. The cleaning brush (54) can be soaked with cleaning product supplied from a cleaning product supply tank (59). Figure 13a A cleaning device (50) in the form of a fluid cleaning blower, such as a compressed air blower (55), is also shown, which enables the transferred product to be removed and / or enables the cleaning product added thereto to be dried for removal. Figure 13b A cleaning device (50) is also shown, which includes a cleaning suction device (58) for aspirating the cleaned transferred product.

[0104] For example, such as Figures 13c to 13e As shown, according to the present invention, the system includes a dry cleaning device (58, 511) and / or a wet cleaning device (56, 56', 512) for the transfer surface (S) to clean the transfer surface (S) of the transferred liquid (3') in the absence or presence of a cleaning product (56'), in particular, the cleaning product is a solvent for dissolving the transferred liquid (3') transferred to the transfer surface (S), especially for dissolving the transferred liquid (3'), and the cleaning product (56') is mixed with a product of the transferred liquid (3') in a liquid or at least partially solidified state.

[0105] In particular, Figure 13c and 13d A dry cleaning device (90) in the form of a first dry cleaning blade (511) is shown, which is configured to clean the transfer surface (S) by dry scraping to separate the resulting product of the transferred liquid (3'), in other words, without applying cleaning product to the transfer surface. The same Figure 13c and 13dA wet cleaning device in the form of a second wet cleaning blade (512) is also shown. In other words, the wet cleaning device is configured to clean a transfer surface (S) such that when the blade (512) scrapes the transfer surface (S), the resulting product of the transferred liquid (3') is mixed with or impregnated with the cleaning product, thereby facilitating the removal of the product from the transfer surface (S).

[0106] The use, either alone or in combination, of the dry cleaning devices (58, 511) and wet cleaning devices (56, 56', 512) on the transfer roller (10), as well as their combination with the foregoing embodiments (e.g., replacing the transfer roller (10) with any other type of transfer element), has not been abandoned. Similarly, other embodiments of cleaning devices besides blades, such as brushes, rollers, blowers, or vacuum cleaners, can be considered, which are generally applicable in both dry and wet applications. For example, Figure 13c and 13d A dry cleaning device in the form of a vacuum (58) is also shown.

[0107] The same Figure 13c and 13d Additionally, auxiliary cleaning devices are described, which are configured to assist the cleaning devices in performing their cleaning functions. Two main types of auxiliary cleaning devices can be distinguished according to their functions, and in the context of this specification, they are referred to as auxiliary dry cleaning devices (90) and auxiliary wet cleaning devices (90'), respectively.

[0108] An auxiliary dry cleaning device (90) is an auxiliary cleaning device that helps to separate the product obtained from the transferred liquid (3') from the transfer surface (S) by means of the coagulation, drying and / or evaporation of the product of the transferred liquid (3') via a dry cleaning device (58, 511). The auxiliary dry cleaning device (90) is thus applied to the dry cleaning devices (58, 511), which are external to or different from them. These auxiliary dry cleaning devices (90) may include, for example, heating devices (such as heaters with IR lamps (93, 94)), air blowing devices (especially with hot air), and / or curing devices by means of electromagnetic radiation, especially by means of UV (91, 92), which clean the product (3') from the transfer surface (S) by means of the dry cleaning device (58, 511).

[0109] Auxiliary dry cleaning devices (90) can be applied before and / or during the removal of product (3') from the transfer surface by dry cleaning devices (58, 511). In particular, these auxiliary devices (90) can be considered for application around the product of the transferred liquid (3') being cleaned by a cleaning device (e.g., blade, brush, roller, blower, vacuum, etc.), where the product is separated from the transfer surface (S). Auxiliary dry cleaning devices (90) facilitate the separation of product (3') from the transfer surface (S) by mechanical or fluid means because they have less adhesion to the transfer surface (S). These auxiliary dry cleaning devices (90) also make it possible to simplify the maintenance of the cleaning device because they are generally easier to clean solid residues on the surface of the cleaning device than liquid residues that may deposit on the surface of the cleaning device.

[0110] Furthermore, the auxiliary wet cleaning device (90') is an auxiliary cleaning device that removes the cleaning product (56') applied by means of drying and / or evaporating the solvent of the product of the transferred liquid (3') transferred to the transfer surface (S), by means of a wet cleaning device (56, 56', 512) on the transfer surface (S) in a controlled manner, and is therefore suitable for wet cleaning devices (56, 56', 512). It can be considered that the removal of the cleaning product (56') performed by the auxiliary wet cleaning device (90') is performed without applying either a dry cleaning device (90) or a wet cleaning device (90') to the same cleaning product (56').

[0111] These auxiliary wet cleaning devices (90') may include, for example, heating devices, such as heaters with IR lamps (95) and / or air blowing devices (97), particularly heaters with hot air. These auxiliary devices (90') are applied to the transfer surface (S) after the cleaning product (56') is applied and before the surface (S) comes into contact with the substrate (2) to transfer the transfer liquid (3). The auxiliary wet cleaning devices (90') make it possible to control the transfer surface (S) to have suitable adhesive properties (such as wetting or surface tension) so that when the transfer surface (S) comes into contact with the transfer liquid (3) on the substrate (2), the transfer liquid (3) is properly transferred to the transfer element (10).

[0112] Similarly, the heat transfer element (10) can also be considered as an auxiliary dry cleaning device (90) and an auxiliary wet cleaning device (90') by means of heat conduction. For example, as Figure 13c and 13dAs shown, the transfer roller (10) is heated by a heater (96), which may include a resistor for localized heating at least on the transfer surface. These auxiliary cleaning devices (96) have the advantage that they can be used both as auxiliary dry cleaning devices (90) and as auxiliary wet cleaning devices (90'). The auxiliary dry cleaning device (90) heats the product of the transferred liquid (3') transferred to the transfer element while the liquid remains on the transfer surface (S) until it is removed by the dry cleaning device. The auxiliary wet cleaning device (90') removes the residue of the cleaning product (56') from the transfer surface (S) by heating it.

[0113] According to the present invention, the system is also envisioned to include a wet cleaning device that includes means for reusing cleaning products (56'). Figure 13e The present invention represents a device for reusing cleaning products (59, 591) and is applied to wet cleaning apparatus (56, 56', 512). These devices (59, 591) for reusing cleaning products (56') include means for recirculating the cleaning product (591) between the cleaning product supply tank (59) and its application on the transfer surface (S) (e.g. by the applicator (56) via the cleaning product circulation conduit (591)) for reuse.

[0114] Similarly, as Figure 13e As shown, the reuse apparatus (59, 591) includes a cleaning product recycling device (592, 593, 594) for reusing cleaning products. The cleaning product recycling device (592, 593, 594) may include a recycling unit (593), which, for example, recycles cleaning products by distillation. The recycling unit (593) is connected to the cleaning product supply tank (59) via a cleaning product circulation conduit (592), and the cleaning product waste extracted through the outlet conduit (594) is recycled by distillation.

[0115] As solvent-based cleaning products, acetone, butyl ethylene glycol, and dipropylene glycol methyl ether (in order of lowest to highest molecular weight) can be used, for example. Solvents with high molecular weights have the advantage of being less volatile, which facilitates their processing and reuse. However, given that the presence of the cleaning product (56') on the transfer element (10) as explained above may alter the wetting or surface tension characteristics during contact, a sufficiently high volatility of the cleaning product is also of interest to facilitate its evaporation after application to the transfer surface (S) before the transfer element (10) returns to contact with the substrate (2) to remove more transfer liquid (3) again. Therefore, a suitable compromise is to use the cleaning product (56'), particularly the solvent of the product of the transferred liquid (3'), with a molecular weight between 55 and 150 g / mol, and preferably between 100 and 125 g / mol, such as, for example, butyl ethylene glycol. In addition, given that higher polarity implies lower volatility of the cleaning product, the volatility of the cleaning product can be altered by modifying its polarity. In order for the cleaning product (56') to properly dissolve the product of the transferred liquid (3'), the appropriate polarity of the product may also be selected, preferably substantially similar.

[0116] According to the present invention, the description of a system including different designated means for performing different steps is generally also applicable to a method for generating a pattern including said steps, which means that the method according to the present invention is not necessarily limited to the direct use of the described system or means.

[0117] Practical examples of generating negative relief or grooves in a substrate according to embodiments of the method of the present invention. To perform this practical example, a substrate in the form of a 5 mm thick SPC (“Stone Plastic Composite” panel was used. A liquid base layer was applied by rollers to the flat front surface of the pretreated substrate. The applied liquid base layer had the following characteristics: Composition: UV-curable transparent polymerizable resin.

[0118] Viscosity (25℃): 7.5 Pa·s.

[0119] Surface tension (25℃): 22 mN / m.

[0120] Density (25℃): 1.4 g / cm3.

[0121] Thickness: 175 µm.

[0122] Then, droplets are injected onto the liquid substrate using digital inkjet printing, and the applied droplets have the following characteristics.

[0123] Composition: A partially UV-curable transparent polymerizable resin, relative to the resin used for liquid substrates.

[0124] Viscosity (25℃): 11 mPa·s.

[0125] Surface tension (25℃): 35 mN / m Density (25℃): 1.0 g / cm3.

[0126] Spray speed: 5 m / s.

[0127] Injection volume: 25 - 45 pL.

[0128] Next, initial UV electromagnetic radiation was applied to the substrate and the assembly of the transfer liquid (a mixture of droplets and liquid substrate) until the substrate partially cured (γ ≅ 25%). Radiation was applied at 120 W / cm using Ga and Hg UV lamps. Once the initial UV radiation was applied, the substrate had a measured surface energy of 58 mN / m (25°C). The transfer liquid is then removed by using four successive transfer rollers according to the invention, which have a substantially smooth rolling surface (transfer surface) and correspond to the flat surface of the substrate, covering the entire width of the substrate, and have the following characteristics.

[0129] Material of the rolling surface: EPDM (ethylene propylene diene monomer rubber), with a Shore A hardness of 25 as measured according to standard ISO 7619-1:2011.

[0130] Roughness of rolling surface: 2 µm (Ra, measured according to ISO standard 4288).

[0131] Outer diameter of the transfer roller (corresponding to the rolling surface): 245 mm.

[0132] Surface energy of the rolling surface: 56 mN / m.

[0133] The transfer rollers are applied by pressing them onto the substrate with increased pressure, and the height of each successive transfer roller is reduced by approximately 50 × 50 µm, starting from the substrate surface level.

[0134] Finally, the final UV electromagnetic radiation was applied to the substrate and the (remaining) transfer liquid components until the substrate curing energy was complete. Radiation was applied at 120 W / cm² using Ga and Hg UV lamps. The total applied energy (the sum of the initial and final radiation energies in the UV-A, UV-B, and UV-C ranges) was measured to be 440 mJ / cm².

[0135] Without applying any subsequent finishing layers or treatments, the relief is achieved directly from the resulting base layer.

[0136] The exemplary embodiment described is made by changing the number (N) of transfer rollers between the initial UV curing and the final UV curing, and by changing the degree of initial curing (γ). Figure 18 The graphs in the figure show the percentage (%p) of the amount of transfer liquid removed relative to the total amount of transfer liquid removed for the initial degree of curing values ​​of γ ≅ 25% (lower curve), γ ≅ 75% (middle curve), and γ ≅ 100% (upper curve) after transfer to each successive transfer roller (N=1 to 8), with no curing performed between successive rollers.

[0137] As can be seen in the graph, a lower initial curing degree, especially γ ≅ 25%, allows for the removal of a larger amount of transfer fluid with a smaller number (N) of transfer rollers. Furthermore, the initial curing is sufficient such that the surface energy of the initially cured substrate is greater than or equal to the surface energy of the rolling surface, preventing the substrate, rather than the transfer fluid, from being transferred to the rolling surface; only the transfer fluid is transferred.

[0138] Comparison of the previous exemplary embodiment with creating a negative relief or groove by means of brushing in the substrate A substrate with the same characteristics as that used in the exemplary embodiment described above was used. Similarly, the liquid substrate and droplets were applied with the same characteristics and in the same manner.

[0139] Unlike the exemplary embodiments described, a single initial UV electromagnetic radiation is applied to the substrate and the component that transfers the liquid (a mixture of droplets and liquid substrate) until the substrate is fully cured (γ ≅ 100), in other words, by applying a total energy of 440 mJ / cm2.

[0140] The transfer liquid is then removed by brushing with metal bristles using two successive brush rollers to remove approximately the same amount of transfer liquid as in the exemplary embodiment described above. The first brush roller applies at a linear velocity and contacts the substrate in the forward direction of the substrate, while the second successive brush roller applies in the opposite direction. The brush rollers used have the following characteristics.

[0141] Outer diameter: 220 mm.

[0142] Bristle length: 40 mm.

[0143] Rotation speed: 650 rpm.

[0144] Without applying any subsequent finishing layer or treatment, the relief on the base is obtained directly from the resulting base layer.

[0145] Figure 14The digital pattern processed in digital inkjet printing on a portion of the obtained embossed area (corresponding to a 7cm × 10cm area at real scale) is shown. The digital pattern is in the form of a grayscale image, where black represents the maximum depth of the embossing (175 μm) and white represents no depth (flush with the substrate).

[0146] Figure 15a It is for the corresponding Figure 14 A vertical photograph of a portion of the digital pattern shown, based on an embossed plan view obtained according to an exemplary embodiment of the invention. Figure 16a A magnified detail of the same photograph from 15a is shown.

[0147] Figure 17a It is aimed at Figure 16a The same area of ​​the photograph, an angled photograph of the relief obtained based on an exemplary embodiment of the present invention.

[0148] and Figure 15a , 16a Compared to 17a, Figure 15b , 16b Figures 17b show photographs corresponding to the same partial area obtained with the same digital pattern, but for this example of relief obtained by applying a brush to create a negative relief.

[0149] As clearly seen in these figures, the relief obtained by means of an exemplary embodiment of the invention has greater clarity, in this example by brushing areas with imperceptible grooves, and without defects due to wear of the metal bristles. While it may be of interest to obtain a pattern with a rustic appearance due to wear of the metal-brushed material, in other cases it may be of interest to obtain a very smooth surface or a suitable gloss, for which, according to the invention, the use of brushes or other known removal devices to remove the transfer liquid can be omitted or reduced. However, according to the invention, the known devices can also be used in a complementary manner.

[0150] List of reference numerals in the attached diagram: 1. A base in the form of a panel 2. Grassroots 3. Transfer fluid 4. Substrate in the form of continuous sheet 5. Feed roll of substrate in the form of continuous sheet 6. Collection rolls of substrates in the form of continuous sheets 7. The obtained pattern 10 Transfer Rollers 10' Reverse roller of the transfer roller 11 First transfer roller 12 Second transfer roller 13 Third transfer roller 14 Rotary actuator for transfer rollers 14 Rotary actuator for transferring the reverse roller 15 Transfer Sheets 16 Transfer Plates 16' Reverse roller of the transfer plate 20 Liquid base layer application device 21. Base layer applicator roller 21' Reverse roller of the base layer applicator roller 22. Base layer quantitative roller 30 Droplet application device 31 Inkjet Printhead 40 Solidification apparatus 41 Initial UV Curing Lamp 42 Final UV Curing Lamp 43 Intermediate UV curing lamp 50 Transfer Liquid Cleaning Device 51 Transfer Surface Cleaning Blade 52 Additional Transfer Surface Cleaning Blades 53 Cleaning Rollers 53' Cleaning roller cleaning blade 54 Transfer Surface Cleaning Brush 55 Clean Air Blower 56 Cleaning Product Applicator 56 Cleaning Products 57 Cleaning Product Collection Container 58 Cleaning Suction Device 59 Cleaning Product Supply Tanks 511 Dry Cleaning Blade 512 Wet Cleaning Blade 591 Circulation catheters for its reusable cleaning products 592 Cleaning product circulation tubing used for its recirculation 593 Recycling unit for cleaning products through distillation 594 Waste recovery outlet conduit for cleaning products via distillation 60 Base transport device 61 First conveyor belt guide rollers 62 Second conveyor belt guide rollers 63 Base Conveyor Belt 64. Rotary actuator for conveyor with guide rollers 70. Surface pressure transfer device against the base layer 71 Displacement actuator for transfer rollers 72 Pressure rollers for transferring sheets 72' Reverse roller of the pressure roller 73 Displacement actuator for pressure roller 74 Sliding pressure element for transferring sheet 74' Reverse roller of sliding pressure element 75 Displacement actuator for sliding pressure element 76 Rotary actuator for pressure rollers 77. Displacement actuator for the transfer plate 80 Continuous feeding device for transfer sheets 81 Transfer Sheet Feed Reel 82 Transfer Sheet Collection Reel 83 Guide rollers for transferring sheets 84 Rotary actuator for the guide rollers of the transfer sheet 85 Sliding guide element for transfer sheet 90 Auxiliary dry cleaning device 90' Auxiliary wet cleaning device 91 UV curing lamp before dry cleaning 92 UV curing lamps during dry cleaning 93. IR heating lamp before dry cleaning 94. IR heating lamps during dry cleaning 95 IR heating lamp after wet cleaning 96 Heat transfer roller heater 97. Air blower after wet cleaning S Transfer Surface %p is the percentage of transferred liquid removed. N Number of transfer rollers γ represents the initial curing degree of the substrate.

Claims

1. A method for generating a pattern (7) on a substrate, comprising, sequentially: Provide a base layer (2) that at least partially covers the substrate. Multiple droplets are applied in or on the base layer (2), and When the transfer surface (S) comes into contact with the liquid (3) without sliding on the base layer (2), at least a portion of the liquid (3), including the droplet or at least partially defined by the droplet, is transferred to the transfer surface (S) by adhering the liquid (3) to the transfer surface (S) so as to at least partially reveal a pattern (7), wherein the pattern (7) is a three-dimensional surface or texture.

2. The method according to claim 1, wherein, The transfer surface (S) is the rolling surface of the transfer roller (10).

3. The method according to claim 1, wherein, The transfer surface (S) is the front surface of the transfer sheet (15).

4. The method according to claim 3, wherein, The transfer sheet (15) is continuously fed.

5. The method according to claim 4, wherein, The transfer sheet (15) is continuously fed from the transfer sheet feed reel (81) and / or continuously fed to the transfer sheet collection reel (82), or continuously fed in a closed loop.

6. The method according to claim 1, wherein, The liquid (3) is transferred while the substrate is being transported or while the substrate is being held in place.

7. The method according to claim 1, wherein, Clean the transferred liquid (3) from the transfer surface (S).

8. The method according to claim 7, wherein, When transferring the additional liquid (3) to the transfer surface (S), clean the transferred liquid (3) on the transfer surface (S).

9. The method according to claim 1, wherein, The transfer surface (S) has such a form that when it comes into contact with the liquid (3), it substantially reproduces the surface of the base layer (2).

10. The method according to claim 9, wherein, For a substrate in the form of a panel (1) or a sheet (4), the transfer surface (S) is substantially flat, and / or the transfer surface (S) is substantially smooth, and / or the transfer surface (S) is substantially elastically deformable.

11. The method according to claim 1, wherein, The transfer surface (S) has a surface roughness of less than or equal to 50 μm.

12. The method according to claim 11, wherein, The transfer surface (S) has a surface roughness of less than or equal to 15 μm.

13. The method of claim 1, comprising a plurality of successive transfer steps.

14. The method according to claim 1, wherein, The transfer surface (S) presses against the base layer (2) and / or is closer to the base layer (2).

15. The method according to claim 14, wherein, When the liquid (3) is transferred, the transfer surface (S) presses against the base layer (2) and / or gets closer to the base layer (2).

16. The method of claim 14, wherein, The pressure on the base layer (2) increases, and / or the height of the transfer surface (S) relative to the base layer surface decreases successively.

17. The method according to claim 16, wherein, For different transfer surfaces (S), the pressure on the base layer (2) increases, and / or the height of the transfer surface (S) relative to the base layer surface decreases successively.

18. The method of claim 1, comprising at least partially solidifying the base layer (2) before and / or after transferring the liquid (3).

19. The method according to claim 18, wherein, When multiple droplets are applied, the base layer (2) is at least partially liquid.

20. The method according to claim 18, wherein, Before the liquid (3) is transferred, the base layer (2) is at least partially solidified so that the surface tension of the base layer (2) is greater than the surface energy of the transfer surface (S) when the liquid (3) is transferred.

21. The method according to claim 20, wherein, Before the liquid (3) is transferred, the base layer (2) solidifies so that the surface energy of the base layer (2) is greater than the surface energy of the transfer surface (S) when the liquid (3) is transferred.

22. The method according to claim 1, wherein, The base layer (2) and / or the liquid (3) solidify at least partially by curing.

23. The method according to claim 22, wherein, The base layer (2) and / or the liquid (3) are cured by radiation and at least partially solidified.

24. The method according to claim 23, wherein, The base layer (2) and / or the liquid (3) are solidified by electromagnetic radiation, at least partially solidifying.

25. The method according to claim 24, wherein, The base layer (2) and / or the liquid (3) are cured by UV curing and at least partially solidified.

26. The method according to claim 1, wherein, Selectively apply droplets.

27. The method according to claim 26, wherein, Droplets are selectively applied based on a digital pattern.

28. The method according to claim 27, wherein, Droplets are selectively applied using digital printing.

29. The method according to claim 28, wherein, Droplets are selectively applied by inkjet printing.

30. A system for performing the method of claim 1 for generating a pattern (7) on a substrate, comprising: A base transport device (60) for transporting the base and the base layer (2), and Droplet application device (30) for applying droplets in or on the substrate (2). Its features It includes at least one transfer element, which is provided with a transfer surface (S) for transferring the liquid (3) to the transfer surface (S) when the transfer surface (S) comes into contact with the liquid (3), and the transfer element is configured such that the contact does not slide on the base layer (2) in a manner synchronized with the transport of the substrate.

31. The system of claim 30, comprising a dry cleaning device (58, 511) for cleaning the transfer surface (S) without the presence of a cleaning product (56').

32. The system according to claim 31, wherein, The cleaning product (56') is a solvent for the product of the transferred liquid that is transferred to the transfer surface (S), and also includes an auxiliary dry cleaning device (90) for facilitating the separation of the product of the transferred liquid from the transfer surface (S) by the dry cleaning device (58, 511) through the product of the transferred liquid by solidification, drying and / or evaporation of the product of the transferred liquid without applying a cleaning device to the same product of the transferred liquid.

33. The system according to claim 32, wherein, The auxiliary dry cleaning device (90) includes: a heating device by thermal radiation; a heating device by thermal conduction; a curing device; and / or an air blowing device.

34. The system according to claim 33, wherein, The auxiliary dry cleaning device (90) includes a heating device that uses electromagnetic radiation.

35. The system according to claim 34, wherein, The auxiliary dry cleaning device (90) includes a heating device via IR (93, 94).

36. The system according to claim 33, wherein, The auxiliary dry cleaning device (90) includes a heating device that conducts heat through a heater (96) of a transfer element.

37. The system according to claim 33, wherein, The auxiliary dry cleaning device (90) includes a curing device that uses electromagnetic radiation.

38. The system according to claim 37, wherein, The auxiliary dry cleaning device (90) includes a curing device using UV (91, 92).

39. The system according to claim 33, wherein, The auxiliary dry cleaning device (90) includes an air blowing device that blows hot air.

40. The system according to claim 32, wherein, The auxiliary dry cleaning device (90) is configured to apply the product of the transferred liquid to the transfer element before and / or during the separation of the product of the transferred liquid from the transfer surface (S).

41. The system according to claim 40, wherein, The auxiliary dry cleaning device (90) is configured to apply the product of the transferred liquid to the transfer element around the dry cleaning device that performs separation.

42. The system of claim 30, comprising a wet cleaning device for cleaning the transfer surface (S) in the presence of a cleaning product (56').

43. The system of claim 42, wherein the cleaning product (56') is a solvent of the product of the transferred liquid transferred to the transfer surface (S), further comprising an auxiliary wet cleaning device (90') for removing the cleaning product (56') applied by the wet cleaning device from the transfer surface (S) by drying and / or evaporating the cleaning product (56') without applying the cleaning device to the same cleaning product (56').

44. The system according to claim 43, wherein, The auxiliary wet cleaning device (90') includes: a heating device by thermal radiation; a heating device by thermal conduction; and / or an air blowing device (97).

45. The system according to claim 44, wherein, The auxiliary wet cleaning device (90') includes a heating device that uses electromagnetic radiation.

46. ​​The system according to claim 45, wherein, The auxiliary wet cleaning device (90') includes a heating device via IR (95).

47. The system according to claim 44, wherein, The auxiliary wet cleaning device (90') includes a heating device that conducts heat through a heater (96) of a transfer element.

48. The system according to claim 44, wherein, The auxiliary wet cleaning device (90') includes an air blowing device (97) that blows hot air.

49. The system according to claim 42, wherein, The wet cleaning apparatus includes means for reusing the cleaning product (56'), wherein the cleaning product (56') is recycled for reuse via a cleaning product recycling loop.

50. The system according to claim 49, wherein, The reuse device further includes a recycling device (592, 593, 594) for the cleaning product (56').

51. The system according to claim 50, wherein, The reuse device includes a recycling device (592, 593, 594) for the cleaning product (56'), which recycles the cleaning product (56') by distillation.

52. The system according to claim 42, wherein, The cleaning product (56') has a molecular weight between 55 and 150 g / mol.

53. The system according to claim 52, wherein, The cleaning product (56') has a molecular weight between 100 and 125 g / mol.

54. The system according to claim 52, wherein, The cleaning product (56') is butyl ethylene glycol.

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