Process and system for generating textures

Abstract

The invention relates to a texture-generating process and system (3). Radiation curing by polymerisation is applied to a base layer (cb) differentially in zones (7, 7', 7") in which curing radiation is inhibited with respect to zones (8) laterally adjacent to the inhibition zones (7, 7', 7"). Textures (3) comprise cavities (4) which are formed by the removal of removable material from the base layer (cb) in the inhibition zones (7, 7', 7"'), in which the base layer (cb) has a substantially lower degree of curing than in the respective adjacent zones (8). The invention is characterized in that the base layer (cb) is spread over a separation layer (cs, cs', cs"), so that, when the removable material is removed, it is substantially separated out through the interface between the base layer (cb) and the separation layer (cs, cs', cs").

Description

[0001] TEXTURE GENERATION PROCEDURE AND SYSTEM

[0002] DESCRIPTION

[0003] OBJECT OF THE INVENTION

[0004] The present invention relates to a method and system for generating textures, i.e., relief surfaces, that can be applied to substrates such as, for example, panels or cardboard. The invention is applicable, for example, to flooring panels, roofing, furniture, packaging, etc.

[0005] More specifically, the invention seeks to introduce improvements in relation to the generation of textures by digital printing and, in particular, inkjet printing.

[0006] BACKGROUND OF THE INVENTION

[0007] Procedures and systems for generating textures using digital printing are well known in the state of the art.

[0008] Patent document WO 2010070485 A2 discloses a procedure for generating textures formed by cavities, by means of inkjet printing, in which, on a base layer of resin, solidifiable by curing radiation, drops of printing are deposited that determine the cavities.

[0009] According to this procedure, the impression droplets are configured to inhibit curing radiation, so that cavities are formed by the removal of extractable material from the base layer in the inhibition zones, for example, using brushes. The material can be removed because in these zones it exhibits a lower degree of curing solidification than in the adjacent lateral areas.

[0010] To inhibit curing radiation, impression droplets can incorporate a curing radiation inhibitor, which physically inhibits the curing radiation, either by completely blocking or masking it, or by partially blocking or filtering it. The solidification gradient that occurs at the interface between the inhibition zones and their adjacent zones corresponds to a difference in cohesive stresses between the two zones. When the material is removed, for example, by the mechanical drag of brush bristles, this difference tends to cause the inhibition zones and the adjacent zones to separate laterally at the interface.

[0011] This type of texture generation process, in which cavities are formed by removing material from the base layer, offers significant advantages, largely due to the fact that the procedures can be performed using inkjet printing. Its flexibility, precision, and speed are noteworthy, as is its ability to produce textures with high mechanical and chemical resistance.

[0012] Furthermore, this type of procedure allows the generation of both visual and haptic and matting textures, depending on the depth of the inhibition zones and the amount of material extracted, allowing, in particular, the generation of micrometric textures.

[0013] In this respect, visual textures are considered to be those whose relief can be distinguished with the naked eye, particularly those presenting cavities with a depth of approximately 100 micrometers or more. Haptic textures are considered to be those that can be distinguished by touch, particularly those presenting cavities with a depth of approximately 10 to 100 micrometers. Matte textures are considered to be those that can be visually distinguished by their degree of gloss, particularly those presenting cavities with a depth of approximately 10 micrometers or less.

[0014] However, known procedures of this type have the drawback that, since the extractable material from the base layer in the inhibition zones must have a lower degree of solidification than in its adjacent zones in order to be extracted, the extraction of the material is difficult when the curing radiation has been applied exceeding a certain degree of solidification of the base layer.

[0015] Removing the extracted material while it is not sufficiently solidified results in the residue being difficult to handle because, due to its stickiness, it adheres to the surfaces of the material removal equipment, such as the surfaces of the brush bristles or the suction ducts of the extracted material.

[0016] Another drawback of known procedures of this type is the difficulty in obtaining textures with deep cavities, since the removable material tends to separate at an intermediate depth and some distance to the sides within the inhibition zone. This is because the adhesive forces at the interface, between the masking zones and the adjacent zones, tend to be stronger than the cohesive forces of the removable material due to its viscoelastic properties.

[0017] Patent document WO 2020039361 A1 also discloses a procedure for generating textures formed by cavities, by means of inkjet printing, in which, on a base layer of resin, solidifiable by curing radiation, drops of printing are deposited that determine the cavities.

[0018] According to this procedure, the impression drops are formulated to inhibit curing. That is, unlike the procedure described previously, in this one the impression drops inhibit the curing of the base layer itself, not necessarily the curing radiation that causes the curing. To achieve this, the impression drops include curing inhibitors, that is, chemical substances that slow down or prevent the polymerization reactions of the curing process.

[0019] Cavities are formed by the removal of extractable material from the base layer in the areas where the impression droplets penetrate, for example, using brushes. The material can be removed because in these areas it exhibits a lower degree of curing solidification than in the adjacent lateral areas.

[0020] This same patent document also discloses other procedures related to the above, insofar as they try to facilitate the extraction of the material to generate the texture.

[0021] According to one of these procedures, the printing drops are configured to lower the glass transition temperature (Tg) of the base layer at room temperature. To achieve this, the printing drops incorporate low-Tg monomers. According to another procedure, the printing drops incorporate liquids that are immiscible or partially miscible with the resin, such as water or PEG acrylate.

[0022] However, the procedures disclosed in this second patent document mentioned have the drawback that they only allow obtaining cavities of shallow depth, since this is limited by the depth of penetration of the printing drops into the base layer when deposited.

[0023] To increase the depth of the cavities, the patent document itself proposes using printing droplets with a surface tension sufficiently different from the surface tension of the base layer resin. Furthermore, the patent document proposes increasing the impact velocity of the printing droplets on the base layer to achieve this.

[0024] However, the procedures disclosed in this second patent document mentioned above do not allow obtaining cavities with the depths allowed by the procedure disclosed in the first patent document mentioned above, even with the measures it discloses to increase the depth of penetration of the impression drops.

[0025] The present invention aims to overcome the limitations of the prior art, in particular by allowing the creation of textures with cavities of different depths, particularly deeper cavities, facilitating the removal of the extracted material, as well as its subsequent handling, especially by avoiding the accumulation of residue of said material on surfaces of the means of removing the material, such as surfaces of the bristles of the brushes or of the suction ducts of the extracted material.

[0026] EXPLANATION OF THE INVENTION

[0027] To achieve the aforementioned objective, as well as additional technical advantages that may be derived from this invention, the invention provides a method for generating textures comprising cavities, which are formed by removing extractable material from a base layer. For this purpose, curing radiation is applied to the base layer, which is curable by polymerization curing radiation. This radiation acts differentially on areas of curing radiation inhibition compared to areas adjacent to these inhibition zones.

[0028] The texture cavities are formed by the removal of extractable material from the base layer in the inhibition zones, where the base layer has a substantially lower degree of curing than in the respective adjacent zones.

[0029] According to the invention, the base layer is spread over another layer, herein called the separation layer. This designation is due to the fact that, as explained below, the layer serves to help separate the extractable material from the base layer. The separation layer is also curable by polymerization curing radiation, and when the base layer is spread over the separation layer, the latter is partially cured.

[0030] Furthermore, according to the invention, at least one inhibition zone extends into the separation layer. Curing radiation acts differentially on the separation layer, specifically on this at least one inhibition zone compared to its adjacent zones; in particular, the curing radiation applied to the base layer acts differentially. Consequently, when the removable material is withdrawn, it separates substantially at the interface between the base layer and the separation layer, with this interface exhibiting substantially less polymerization adhesion in the at least one inhibition zone than in the respective adjacent zones.

[0031] In the context of the present invention, "inhibition zones" can be understood as the zones in which the curing radiation is inhibited, which may not necessarily be part of the base layer only, but also of the separation layer, other lower layers or even the substrate on which these layers are spread and, in general, any part of the finished product after applying the procedure.

[0032] Furthermore, the existence of an "inhibition zone" is not limited, by definition, to the time interval in which radiation inhibition occurs, but can also be understood, in a broader sense, as the area in which inhibition has occurred or will occur as a result of the procedure. For example, at the moment when the base layer has not yet spread and, therefore, inhibition has not yet occurred, conceptually a portion of the inhibition zone can extend into the separation layer, where radiation is subsequently inhibited.

[0033] Extraction of base layer material in inhibition zones is possible because in these zones the base layer has a substantially lower degree of curing solidification than in adjacent zones of the base layer.

[0034] In this context, the portion being removed can be extracted from a base layer that is, for example, highly gelled, while the surrounding base layer may remain solid. To achieve this, the means of removing the extractable material, such as brushes, work by dragging away the highly gelled portion, while the rest of the base layer remains fixed.

[0035] Unlike the prior art, the existence of a separation layer according to the invention also makes it possible to separate or detach the removable material, substantially through the interface between the base layer and the separation layer, thus facilitating the removal of the removable material.

[0036] To this end, the invention takes advantage of the production of differential adhesion at the interface between the base layer and the separation layer, so that the adhesion produced in the inhibition zones that reach the separation layer is substantially less than in the respective zones adjacent laterally to the separation layer.

[0037] This production of adhesion is generally due to two main natural mechanisms related to the polymerization process, particularly crosslinking, of polymeric materials, as explained below.

[0038] Polymeric materials that can be used in the base and separation layers include, for example, photocurable resins, particularly those cured using UV radiation. Examples include epoxy, urethane, and polyester acrylates.

[0039] The first mechanism is based on the fact that the application of curing radiation on the separation layer leads to a decrease in the number of free radicals of polymer chains available to crosslink or intertwine with other polymer chains as the degree of curing increases.

[0040] The second mechanism is based on the fact that the application of curing radiation to the interface between the base layer and the separation layer, once the base layer has been spread over the separation layer, leads to the fact that, as the degree of curing increases, the available polymer chain free radicals join together forming bonds, i.e., crosslinking or intertwining the polymer chains.

[0041] Applying curing radiation to the separation layer, particularly before applying the base coat, affects the availability of free radicals to form bonds on the separation layer's surface. Increasing the degree of curing reduces the presence of free radicals.

[0042] Applying curing radiation to the interface between the base layer and the spacer layer affects the formation of bonds between the base layer and the spacer layer, based on available free radicals. Increasing the degree of curing increases the number of bonds formed from the free radicals present.

[0043] Preferably, the invention provides that the curing radiation that acts differentially on the base layer also acts differentially on the separation layer during at least part of the time that the separation layer is still partially cured.

[0044] A sufficiently high degree of curing of the separation layer, prior to extending the base layer, allows the presence of available free radicals to be low and, therefore, the application of differential curing radiation at the interface to be relatively more effective.

[0045] Conversely, a lower degree of curing of the separation layer allows for a greater presence of available free radicals and, therefore, requires greater differential curing radiation energy at the interface to produce interface separation.

[0046] Furthermore, the invention preferably also provides that, prior to applying the base coat, the separation layer is differentially cured in areas of radiation promotion, substantially coinciding with at least one inhibition zone at the interface, compared to its adjacent areas. In particular, it is provided that the separation layer is selectively cured in these radiation promotion zones prior to applying the base coat.

[0047] Thus, prior to applying the base coat, the separation layer is partially cured, though not necessarily along its entire length. Specifically, the separation layer may be fully cured only in the promotion zones and partially cured in adjacent areas. For example, the separation layer may be partially cured along its entire length before applying differential curing radiation to the promotion zones.

[0048] By promoting curing radiation in the separation layer's promotion zones, prior to base layer application, the effect of reducing the presence of free radicals within that zone, thus preventing them from forming bonds at the interface with the base layer, is intensified. This effect can be further maximized by selectively curing the entire separation layer or curing only those promotion zones.

[0049] This differential curing radiation action in the promotion zones can be carried out in addition to or as an alternative to the differential curing radiation action in the inhibition zones of the interface between the base layer and the separation layer when the separation layer is partially cured.

[0050] In light of the aforementioned technical rules and the explanation in this document, a person skilled in the art can establish precise limits for implementing the invention based on the desired results. This can be achieved by adjusting process design variables without excessive experimentation. Examples of process design variables according to the invention are those listed below.

[0051] The type of means used to remove the extractable material from the base layer, such as brushes, influences the drag force exerted on the material for its extraction. According to the invention, any type of means for removing extractable material can be used, including brushing, contact transfer means (particularly contact transfer rollers), suction, blowing, or fluidic propulsion (compressed air, water jet, sandblasting, etc.).

[0052] The pressure exerted by the removal means on the base layer to remove the removable material, in particular, for example, due to the drag force of the brushes, can also be regulated and, therefore, can be adjusted by influencing the design of the procedure according to the invention.

[0053] Contact transfer means, particularly in the form of rollers, are disclosed in patent document WO 2022180292 A1. In particular, a contact transfer roller can be used, for example, in a first stage of material removal to remove a more liquid or less gelled portion of the removable material, followed by a brush to remove the remaining material down to the separation layer. In general, according to the invention, any transfer means can be used, in particular transfer rollers of any type, for example, absorbent rollers.

[0054] The specific composition of the separation layer also influences the radiation energy required to achieve a certain degree of curing or a certain presence of free radicals on the surface to which the curing radiation is applied. For example, when using a light-cured resin, the addition of photoinitiators generally increases the curing rate.

[0055] Furthermore, the specific composition of the base layer influences the curing of both the base layer and the separation layer. For example, when using a UV-curable resin, the addition of photoinitiators generally increases the curing speed and the depth to which the radiation penetrates.

[0056] The thickness of the base layer also influences the curing of both the base layer and the separation layer. Generally, the greater the thickness of the base layer—that is, the depth at which the separation layer is located—the less radiation energy reaches this layer. Furthermore, the way in which the differential curing radiation is applied to the base layer also affects the curing of both the base layer and the separation layer. Factors such as the degree of radiation inhibition, the amount of radiated energy, the radiation power, the type of radiation, and the processing speed can all have an impact.

[0057] For example, regarding the type of radiation used, for UV photocurable resins, Ga lamps allow for a deeper cure than Hg lamps.

[0058] In short, the invention makes it possible for the base layer material to be easily removable to form the texture cavities, being able to be easily detached from its side faces due to the difference in solidification states and from its lower face due to the lesser adhesion with the resulting separation layer.

[0059] In particular, the extraction of base layer material for deeper cavities is facilitated compared to procedures known in the prior art. In this respect, the procedure according to the invention allows, in particular, for obtaining more precise textures since it allows for the extraction of only the necessary amount of base layer material.

[0060] Furthermore, since the cavities thus obtained reach the separation layer, passing through the base layer, cavities with a precise depth can be obtained, as it is equivalent to the thickness of the base layer.

[0061] In any case, the invention contemplates that, in addition to the cavities that reach the separation layer, the texture includes shallower cavities, depending on the depth of the respective inhibition zones. Thus, depending on the depth, visual, haptic, and / or matting textures can be obtained on the same surface of the base layer, providing a wide variety of textured finishes.

[0062] The invention is also compatible with obtaining textures in register with other motifs, for example, decorative or colored ones. In particular, the base layer and the separation layer can be transparent and spread over a decorative layer provided with decorative motifs, so that the generated textures are in register or correspondence with said motifs.

[0063] The configuration of texture layers with decorative layers in register also offers the possibility of creating a wide variety of designs, for example, designs imitating natural motifs, such as wood grain.

[0064] The following section provides definitions and clarifications of terms used in this document. These terms should be interpreted, in principle, according to their common technical meaning and in a broad sense, allowing for a flexible understanding adapted to each associated concept.

[0065] In the context of the present invention, “curing radiation inhibition” includes both the concept of “reduction of applied radiation energy” and the concept of “suppression of applied radiation energy” in the inhibition zones, with respect to their laterally adjacent zones.

[0066] In particular, the term “inhibition” of radiation includes both “masking” or total blocking of radiation, and “filtering” or partial blocking of radiation.

[0067] Furthermore, in the context of the present invention, “curing radiation promotion” includes the concept of “increasing the applied radiation energy” in the promoted zones, relative to their laterally adjacent zones. In particular, the term “radiation promotion” includes the concept of radiation “concentration.”

[0068] “Curing radiation” refers, in particular, to electromagnetic curing radiation, for example, UV radiation. The term “curing” encompasses the concept of “polymerization,” that is, the formation of polymer chains (polymerization proper) and the cross-links between polymer chains (crosslinking).

[0069] The "degree of cure" of a material refers to the degree of transformation the material has undergone, quantified with respect to its complete cure, in which the material's monomers have been fully transformed into polymer chains. Thus, for example, a degree of cure of 100% corresponds to a fully cured material, and 0% to a material in its monomeric state.

[0070] In the context of the present invention, the concept of "degree of curing" includes the concept of "degree of solidification." The "degree of solidification" of a material allows for the quantification of its solidification relative to a maximum solidity, on a predetermined scale. Thus, a degree of solidification of 100% corresponds to a substantially solid material, and 0% to a substantially liquid material.

[0071] As the degree of curing increases, the degree of solidification of a material also increases. Typically, polymeric materials are used whose glass transition temperature (Tg) of the fully cured material is higher than the ambient temperature of use of the final product (preferably 10-20°C). 2 greater), so that the degree of curing corresponds to the degree of solidification.

[0072] The degree of curing or solidification can be measured in relation to a scale of radiation energy applied per unit area, considering, for example, the power of curing radiation that is irradiated and the processing speed.

[0073] A hardness scale can also be used to measure the degree of solidification. For example, using an HB indentation pencil, where 6H corresponds to maximum hardness (100% solidification or substantially solid) and 3B to minimum hardness (0% solidification or substantially liquid).

[0074] The degree of solidification can also be observed qualitatively. For example, one can distinguish between liquid (L), gel (G), solid gel (G+), or solid (S) states. A material in a gel state (G) can be touched without being dragged along, unlike a liquid state (L), which can be dragged along when touched. A material in a solid gel state (G+) would be in an intermediate state between gel (G) and solid (S). Thus, a liquid state (L) would correspond approximately to a degree of solidification of 0–33%, a gel state (G) to 34–66%, a solid gel state (G+) to 67–99%, and a solid state (S) to 100%.

[0075] In this sense, measuring or observing the degree of curing or solidification, for example, as indicated, especially allows the expert in the field to carry out tests to adjust design variables of the procedure.

[0076] In relation to the descriptive terms referred to below that have been mentioned above and that appear throughout this report, the following clarifications should be noted.

[0077] The term “at least one”, for example, referring to “at least one zone of inhibition”, includes, in particular, “all”, i.e., for example, “all zones of inhibition”.

[0078] The term “sufficiently”, for example, referring to “sufficiently high”, includes, in particular, “substantially” or at least the referred value, that is, also any higher value.

[0079] The term “over”, for example, referring to “over the separation layer”, includes, in particular, “directly over” or “substantially over”.

[0080] Returning to the technical explanation of the invention, additional preferred embodiments are described below. In these embodiments, the process according to the invention is applied including features complementary to those described so far, which provide additional advantages.

[0081] Preferably, according to the invention, it is envisaged that, upon removal of the extractable material, the extracted material exhibits a degree of curing, in particular a degree of solidification, sufficiently high to substantially prevent its adhesion to surfaces of the means used to remove the extractable material. These surfaces may be, in particular, the bristle surfaces of extraction brushes, the surfaces of suction ducts for the extracted material, etc.

[0082] In particular, it is understood that, when removing the extractable material from the base layer, the extracted material should have a degree of solidification by curing substantially greater than or equal to 70%, preferably 80%, and more preferably 85%.

[0083] On the other hand, when removing the extractable material from the base layer, the extracted material preferably exhibits a degree of solidification lower than the maximum degree of solidification that would prevent its convenient extraction due to excessive cohesion of the base layer. Specifically, the extracted material is intended to have a degree of solidification by curing substantially less than 100%, preferably less than 90%, and more preferably less than 85%.

[0084] Qualitatively, it can be observed that the extracted material with a degree of solidification between 80% and 85% has a rubbery appearance, similar to a residue left on paper after erasing a pencil stroke with an eraser.

[0085] In this way, advantageously, the invention allows the generation of textures without soiling the surfaces of the means of removing the removable material, unlike prior art texture generation procedures, especially for deeper textures, which tend to leave sticky residues on the surfaces that are difficult to clean.

[0086] Furthermore, once the extracted material is removed, the invention offers the advantage that the residue consisting of said material is easier to store and process, given its more solid state. In general, the material extracted according to the invention can be recycled or reused.

[0087] In this regard, processes and systems are known in the state of the art that apply additional curing radiation to the surfaces of the means of removing extractable material, in order to solidify the residues and thus facilitate their cleaning from said surfaces.

[0088] The invention has the advantage that these processes or systems can be dispensed with, since the extractable material can be removed directly in a sufficiently solid state. However, these processes and systems can also be applied to the present invention.

[0089] In prior art texture generation processes, it is not possible to remove the extractable material when it is as cured or solidified as it may be when applying the process according to the invention. This is because, lacking a separation layer configured as in the invention, the only mechanism for extracting the material from the base layer is by softening the material in the inhibition zone relative to its laterally adjacent zones, since its hardening or solidification effectively prevents its extraction.

[0090] The following describes various embodiments related to the application of radiation for differential polymerization curing. According to the invention, the curing radiation can act differentially on the base layer and the separation layer.

[0091] Preferably, the invention involves selectively depositing a curing radiation inhibition product onto the inhibition zones and / or the zones adjacent to the promotion zones. Alternatively or additionally, the invention involves selectively depositing a curing radiation promotion product onto the promotion zones and / or the zones adjacent to the inhibition zones.

[0092] “Radiation inhibition product” means any product which, placed on the inhibition zones or zones adjacent to the promotion zones, inhibits, in particular, masks or filters, radiation in those zones.

[0093] “Radiation promotion product” means any product which, placed on promotion zones or zones adjacent to inhibition zones, promotes, in particular, concentrates radiation in those zones.

[0094] Furthermore, the invention also provides that the curing radiation inhibition product deposited on the inhibition zones additionally comprises a curing inhibitor and / or a glass transition temperature (Tg) lowering agent. This helps to reduce the degree of curing, particularly the degree of solidification or softening, of the removable material in the inhibition zones of the base layer, thus facilitating its extraction and removal.

[0095] In this regard, the inhibition product can also be configured to cure via radiation, to be immiscible or partially miscible in the base layer, and / or to sublimate. These options further facilitate the extraction and removal of the extractable material in a more solid state.

[0096] The promoting product and / or the inhibiting product that are deposited on the separation layer can be removed by suitable material removal means, prior to spreading the base layer and once the corresponding curing radiation has been applied.

[0097] In accordance with other embodiments, the invention also contemplates that, prior to extending the base layer, on the separation layer, in areas substantially coinciding with the at least one inhibition zone, a barrier product to radiation curing polymerization is deposited.

[0098] A “polymerization barrier product” means any product that, by itself and / or in combination with other products, is incapable of, or prevents, polymerization. A polymerization barrier product may include, in particular, a curing inhibitor and / or a curing inert agent. For example, water or specific solvents may be used.

[0099] Thus, once the base layer is spread over the separation layer, a barrier is created at the interface, in which the curing radiation acts differentially, in the inhibition zones where the barrier product is deposited with respect to its adjacent zones, producing less adhesion by polymerization in these zones.

[0100] Furthermore, the deposited radiation inhibition product, curing radiation promotion product, and / or polymerization barrier product can be configured so that, once deposited, they remain on the coating, mix with the coating material, or penetrate the coating, base coat, or separation layer, as appropriate. This can be influenced, for example, by selecting a chemical composition for the printing droplets, as well as for the base coat, in particular to provide suitable surface tension and / or viscosity.

[0101] Likewise, for example, this can also be influenced by whether the inhibition product is curable, since a higher degree of solidification of the impression drops can favor the drops remaining on the surface of the base layer, while in a more liquid state they tend to penetrate the base layer.

[0102] In particular, depending on the configuration chosen for the polymerization barrier product, in terms of its ability to remain on, mix with, or be introduced into the separation layer once deposited, a greater or lesser barrier effect can be achieved.

[0103] For example, if the barrier product consists of an agent that is inert to curing, a greater barrier effect can be achieved if it remains on the surface of the separation layer. In this case, once the base coat is applied over the separation layer, the barrier product will be embedded between the two layers, breaking the polymerization bond between them.

[0104] In contrast, for example, if the barrier product consists of an agent inert to curing and is mixed with the separation layer, the breaking of the adhesion bridge by polymerization between both layers will be mitigated, as the barrier product is dispersed within the separation layer.

[0105] Likewise, for example, if the barrier product consists of a curing inhibitor and is mixed with the separation layer, a mitigated bond break can also be expected, due to the curing inhibition caused by the barrier product in the mixing zone.

[0106] The invention also contemplates that the radiation-promoting product and the polymerization-barrier product can be combined on the same separation layer. In particular, a barrier product can also be a radiation-promoting product.

[0107] Preferably, according to the invention, the radiation inhibition product, the radiation promotion product, and / or the polymerization barrier product are deposited in the form of printing droplets by inkjet printing. Inkjet printing provides flexibility, precision, and speed to the process.

[0108] Digital inkjet printing also facilitates obtaining cavities with predetermined depth levels by selecting the volume of ink drop per impression point and / or the spacing between impression points. Generally, a larger volume of ink drop per impression point results in a greater depth of inhibition or promotion zone, and therefore, a greater potential depth of the resulting cavities. Likewise, a greater spacing between impression points generally results in a shallower depth of inhibition or promotion zone, and therefore, a shallower potential depth of the resulting cavity.

[0109] As explained, the texture generation process according to the invention allows for obtaining textures with cavities that can extend to the full thickness of the base layer. In particular, base layers with a thickness greater than or equal to 100 micrometers can be used, preferably 150 micrometers, and more preferably 200 micrometers.

[0110] A finished product made according to the invention comprises a substrate on which the texture is generated by a procedure as described in this specification.

[0111] According to another aspect, the invention also provides a texture generation system, adapted to carry out a procedure as described in this document.

[0112] According to the invention, the system comprises means for extending a base layer, means for applying curing radiation configured to act differentially on the base layer, and means for removing extractable material from the base layer.

[0113] Characteristically, the system comprises means for extending a separation layer, means for applying curing radiation onto the separation layer, and a controller configured to actuate said means (for extending layers, applying curing radiation, and removing material) by carrying out a procedure according to one of the claims.

[0114] Preferably, these curing radiation application means, configured to differentially affect the base layer, comprise an inkjet printer, particularly a single-pass printer. The inkjet printer is configured to inject curing radiation inhibition product onto the base layer.

[0115] The system inherits the effects and technical advantages of the procedure according to the invention and, advantageously, allows its automation, as well as the signaling of the generation of textures on substrates.

[0116] BRIEF DESCRIPTION OF THE DRAWINGS

[0117] The invention is described in greater detail below for illustrative and non-limiting purposes, as well as with respect to a preferred embodiment by way of example, with reference to the accompanying drawings. In the drawings:

[0118] Figure 1 shows a representation of the digital information of an example of a texture to be generated.

[0119] Figure 2 shows a texture generated based on the representation of Figure 1, plan view.

[0120] Figures 3 to 6 show a first embodiment of the texture of figure 2 according to the invention, viewed in section according to A'-A' or B'-B'.

[0121] Figures 7 and 9 show a second form of embodiment of the texture of figure 2 according to the invention, viewed in section according to A'-A'.

[0122] Figures 8 and 10 show a third form of embodiment of the texture of figure 2 according to the invention, viewed in section according to A'-A'.

[0123] Figures 11 and 12 show a fourth form of embodiment of the texture of figure 2 according to the invention, viewed in section according to A'-A'.

[0124] Figure 13 shows a fifth embodiment of the texture of Figure 2 according to the invention, viewed in section.

[0125] Figure 14 shows a sixth embodiment of the texture of Figure 2 according to the invention, viewed in section.

[0126] Figure 15 shows a curing diagram for three examples of the procedure according to the invention, based on the embodiment of Figure 14.

[0127] Figure 16 schematically shows an example of a system embodiment according to the invention, suitable for carrying out an example of a procedure embodiment based on Figure 15.

[0128] DETAILED DESCRIPTION OF THE INVENTION

[0129] Figure 1 shows a representation of the digital information of an example texture (3) with cavities (4), which can be generated by a procedure or system (1) according to the invention. It is a matrix representation in which each cell, for a given row and column, corresponds to a pixel or unit of information about the depth of the cavities (4) of the texture (3) to be generated.

[0130] In this example, each pixel can take one of four possible values, where each value is assigned a level of texture cavity depth (3) to be obtained. These four values ​​are: level 0 (the cell appears empty), level 1 (the cell appears with a circle of smaller diameter), level 2 (the cell appears with a circle of intermediate diameter), and level 3 (the cell appears with a circle of larger diameter).

[0131] Level 0 means there is no cavity (4), a higher level means a greater depth of the cavity (4) to be generated, ranging from a minimum depth (level 1), to a maximum (level 3), passing through an intermediate one (level 2).

[0132] Figure 2 shows an example of a texture (3) generated on a substrate (2), based on the representation in Figure 1. For simplicity, the texture (3) shown was created with a scaling of one pixel per point. Textures of greater or lesser precision can be obtained with a higher or lower number of pixels per point, respectively.

[0133] The texture (3) generated as seen from section A'-A' is the one obtained for the (imaginary) section AA of the representation in figure 1. Similarly, section B'-B' is the one obtained for the (imaginary) section BB of the representation in figure 1.

[0134] Figures 3 to 6 refer to a first form of realization of the texture of figure 2.

[0135] On one side, figures 3 and 4 show different sections of the substrate (2), respectively, corresponding to A'-A' and B'-B', at a time prior to the generation of the texture (3), that is, when differential curing radiation acts on the base layer (cb).

[0136] On the other hand, figures 5 and 6 show the true sections of the substrate (2), respectively, A'-A' and B'-B', that is, when the texture (3) has already been generated.

[0137] Referring to figures 3 and 4, as can be seen, to reach the time instant represented in the figures, the following steps have been previously carried out: extension of a separation layer (es) on the substrate (2), extension of a base layer (cb) on the partially cured separation layer (es), and application of curing radiation inhibition product (5) on the base layer (cb).

[0138] The inhibition product (5) can be applied, for example, by inkjet printing, in particular, using a single-pass inkjet printer. In such a case, by selecting the volume of print droplet ejected per print dot and / or the spacing between print dots, a desired distribution of the quantity of inhibition product (5) on the base layer (cb) can be achieved.

[0139] The distribution of the amount of inhibition product (5), in particular, as impression drops, influences the shape and size of the inhibition zones (7, 7', 7") of curing radiation.

[0140] As depicted in the figures, generally, due to the inhibition effect of the inhibition product (5), a greater amount of product (5) at a point produces deeper inhibition zones (7, 7', 7"), and a greater dispersion of the inhibition product (5) around a point produces shallower inhibition zones (7, 7', 7").

[0141] Thus, the inhibition zones (7) are the deepest, reaching the separation layer (es) and even the substrate (2), as shown in Figures 3 and 4. The inhibition zones (7') reach an intermediate depth, and the inhibition zones (7") reach the shallowest depth. The inhibition zones (7, T, 7") are confined laterally by their adjacent zones (8). The inhibition zones (7, 7', 7"), as well as the adjacent zones (8), can extend into the base layer (cb) and even into lower layers or the substrate (2).

[0142] Figures 5 and 6 show the texture (3) already generated, with the cavities (4) formed. To reach the point depicted in these figures, starting from the point shown in Figures 3 and 4, following the procedure according to the invention, material was removed from the base layer (cb), for example, by brushing, resulting in the various cavities (4) after differentially applying curing radiation to the base layer (cb). The removal of the extractable material occurs due to the lower degree of curing or solidification in the inhibition zones (7, 7', 7") compared to the adjacent zones (8) laterally of the base layer (cb).

[0143] Characteristically, the inhibition zones (7) reach the separation layer (es) and, upon removal of the material from the base layer (cb), said material is substantially separated by the interface between the base layer (cb) and the separation layer (es).

[0144] When this material is removed, the interface between the base layer (cb) and the separation layer (es) exhibits substantially less polymerization adhesion in the inhibition zone (7) than in its adjacent zones (8), which facilitates the detachment or separation of the base layer (cb) at the interface.

[0145] As can be seen in Figures 3 and 4, where the inhibition zones (7, 7”, 7”’) have been delineated, the curing radiation that acts differentially on the base layer (cb) also acts differentially on the separation layer (es) for at least part of the time that the separation layer (es) is still partially cured. Thus, the available free radicals intertwine at the interface to a lesser extent in the inhibition zone (7) than in its adjacent zones (8).

[0146] Figures 7 and 9 refer to a second form of embodiment of the texture of figure 2 according to the invention.

[0147] On one hand, Figure 7 shows a section of the substrate (2) along A'-A', at a time prior to the generation of the texture (3), corresponding to when differential curing radiation acts on the base layer (cb). On the other hand, Figure 9 shows the actual section of the substrate (2), A'-A', that is, when the texture (3) has already been generated.

[0148] Unlike the first embodiment, here the base layer (cb) comprises a plurality of base sublayers (cb1, cb2) overlapping one another. In the particular embodiment shown, there are two base sublayers (cb1, cb2) that constitute the base layer (cb). Partial curing of the base layer (cb1) may occur between the application of the base layer (cb1) and the application of the base layer (cb2) to increase its cohesion and thus prevent a detrimental drag effect of the base layer (cb1) by the base layer (cb2), particularly between any successive layers and especially with the thicker layers.

[0149] This method is advantageous because it allows for greater flexibility in obtaining textures with coatings of varying base layer thicknesses (cb). It also offers the advantage of producing thicker base layers (cb) by preventing the base layer (cb) from overflowing the substrate edges (2) when applied, thus enabling more precise thicknesses.

[0150] Figures 8 and 10 refer to a third form of embodiment of the texture of figure 2 according to the invention.

[0151] Unlike the first or second embodiments, here a plurality of base layer (cbl, cbll, cblll) and gap layer (esl, csll, cslll) pairs are extended over one another, such that different inhibition zones (7) reach respective gap layers (esl, csll, cslll). In the particular case of the embodiment shown, three base layer (cbl, cbll, cblll) and respective gap layer (esl, csll, cslll) pairs have been extended.

[0152] Specifically, the extension of the different layers involves the selective application of differential curing radiation to each separating layer (esl, csll, cslll) and its immediately superior base layer (cbl, cbll, cblll). In this regard, it is envisaged that the extractable material from the immediately superior base layer can be extracted along with the material from the other superior layers in the inhibition zone (7). Advantageously, this embodiment makes it possible to obtain more precise depth levels, as they can be linked to corresponding base layer thicknesses, especially to discrete depth level values. In the particular case of the embodiment shown, there are three discrete depth levels, obtained for respective inhibition zones (7), depending on their depth.

[0153] In particular, these second and third forms of realization are compatible with each other, since each base layer (cbl, cbll, cblll) can be made up of a plurality of base sublayers (cb1, cb2).

[0154] Figures 11 and 12 refer to a fourth form of embodiment of the texture of figure 2 according to the invention.

[0155] On one side, Figure 11 shows a section of the substrate (2) according to A'-A', at a time before the extension of the base layer (cb), corresponding to when differential curing radiation acts on the separation layer (es).

[0156] On the other hand, Figure 12 shows a section of the substrate (2) according to A'-A', at a time before the generation of the texture (3), corresponding to when differential curing radiation acts on the base layer (cb).

[0157] Prior to extending the base layer (cb), differential curing radiation acts on the separation layer (es) in promotion zones (9), substantially coinciding with the inhibition zone (7) at the interface between the base layer (cb) and the separation layer (es).

[0158] The curing radiation acts differentially on the separation layer (es) in the promotion zone (9) compared to its adjacent zones (8) laterally. This reduces the number of free radicals available to interlock during the subsequent bonding phase with the base layer (cb) in the promotion zones (9) compared to the adjacent zones (8).

[0159] The promotion zones (9) are produced, in this example, by depositing radiation promotion product (6) onto the separation layer (es), for example, by inkjet printing, in particular, by a single-pass inkjet printer.

[0160] The radiation promotion product (6) in this case also acts as a polymerization barrier, containing, for example, a curing inhibition agent that acts on the separating layer material (es) when mixed with it. Thus, as shown in Figure 12, this product (6) becomes embedded between the separating layer (es) and the base layer (cb) in an area substantially coinciding with the inhibition zone (7) in the inference, reducing polymerization adhesion in that area.

[0161] In particular, this fourth embodiment is compatible with any of the embodiments set out, since the method for reducing adhesion in the interface, in the inhibition zones (7) with respect to their adjacent zones (8), by means of the differential action of curing radiation in zones of promotion (9) of radiation and / or barrier to polymerization, can be applied to interfaces between different base layers (cb, cbl, cbll, cblll) and separation layers (es, esl, csll, cslll).

[0162] Figure 13 relates to a fifth embodiment of the texture of Figure 2 according to the invention. The figure shows a section of the substrate (2) at a time prior to the differential action of curing radiation on the base layer (cb).

[0163] According to this embodiment, the separation layer (es) incorporates reinforcing particles (pr) and / or thickening agents. This allows the cohesion of the separation layer (es) to be increased by extending the base layer (cb).

[0164] The differential action of curing radiation, after the instant represented in figure 13, can take place, for example, as described for any of the above embodiments, arranging the separation layer(s) of said embodiments with this configuration.

[0165] In particular, this fifth embodiment is also compatible with any of the embodiments described, since a separation layer (es, esl, csll, cslll) configured in this way can be applied to any of them. Figure 14 relates to a sixth embodiment of the texture of Figure 2 according to the invention. The figure shows a section of the substrate (2) at a time prior to the differential action of curing radiation on the base layer (cb).

[0166] According to this embodiment, the separation layer (es) is spread onto a substrate (2) by means of a decoration layer (cd) and a protective layer (cp) for the decoration layer (cd). The decoration layer (cd) may be, for example, inkjet printed, in particular by a single-pass inkjet printer.

[0167] Any other arrangement of intermediate layers between a separation layer (es) and the substrate (2) is also possible according to the invention. In general, the separation layer (es) can be applied to the substrate (2) directly or through at least one intermediate layer, which, for example, can be selected from at least one primer layer for decorative or textured layers, at least one decorative (cd) or textured layer, at least one protective (cp) layer for decorative or textured layers, and a combination thereof.

[0168] The differential action of curing radiation, after the instant represented in figure 14, can take place, for example, as described for any of the above embodiments, by arranging intermediate layers between the separation layer (es) and the respective substrate (2).

[0169] In particular, this sixth embodiment is also compatible with any of the embodiments described, since in any of them, in particular, a decorative layer (cd) and a protective layer (cp) can be applied beforehand.

[0170] Figure 15 shows a curing diagram for three embodiments of the procedure according to the invention. Each embodiment corresponds to a separation layer (es, es', es") with different curing rates.

[0171] By way of example, the embodiments are based on an embodiment such as that shown in Figure 14, in conjunction with any of the embodiments shown in Figures 3 to 10, in which a curing radiation inhibition product (5) is applied. In this respect, the texture (3) is generated on a substrate (2), on which a decoration layer (cd) is applied. A protective layer (cp) is spread over the decoration layer (cd). A separation layer (es, es', es") is applied over the protective layer (cp), and over this, a base layer (cb) is applied, on which the texture (3) is generated.

[0172] The curing diagram represents, on the y-axis, the degree of curing or solidification of the different layers used (in %) and, on the x-axis, the time (in time units, ut). Each layer (cd; cp; es, es', es”, cb) is represented by a graph. For the separation layer (es, es', es”), three graphs are shown, each of which refers to one of the three implementation examples.

[0173] As can be observed, the curing curve of the decorative layer (cd) extends from the moment (ted) of layer (cd) application, the moment when the layer (cd) is liquid. As the curing time increases, the degree of curing increases. At time (tep), the protective layer (cp) is applied over the decorative layer (cd). Due to the covering effect of the protective layer (cp) over the decorative layer (cd), as the exposure time to the curing of the protective layer (cp) increases, the decorative layer cures at a slower rate, which is observed in the decreasing slope of the curing curve of the decorative layer (cd).

[0174] In order to apply the protective layer (cp) over the partially cured decorative layer (cd), the degree of curing of the decorative layer (cd) must be high enough to prevent drag effects from the decorative layer (cd) when applying the protective layer (cp). At the same time, the degree of curing of the decorative layer (cd) must not be so high as to compromise the bond between the layers through polymerization.

[0175] At time (tes), the separation layer (es, es', es") is extended over the protective layer (cp). Analogously to what has been explained for the protective layer (cp), the extension of the separation layer (es) modifies the curing rate of the protective layer (cp)—it would also modify that of the decorative layer (cd) if it were partially cured. Likewise, at time (tes) when the extension of the separation layer (es) is enhanced, the protective layer (cp) is sufficiently cured to prevent drag effects from the protective layer (cp) but not so cured as to impair the bond between layers through polymerization.

[0176] At time (teb), the base layer (cb) is spread over the separation layer (es, es', es"). Similarly to what has been explained for the previous layers, the spread of the base layer (cb) modifies the curing rate of the preceding layers. Likewise, at time (teb), the separation layer (es, es', es") is sufficiently cured to prevent drag effects from the separation layer (es, es', es") but not so cured as to impair the bond between layers through polymerization.

[0177] Specifically, at time (tpi), an inhibition product (5) is applied to the base layer (cb). In the curing graph of the base layer (cb), this is reflected in a bifurcation of the graph at time (tpi) into two branches. One branch corresponds to the curing of the portion of the base layer (cbi) in the inhibition zone (7), which reaches the separation layer (es, es', es"). The other branch corresponds to the curing of the portion of the base layer (cba) in the adjacent zones (8), which are not influenced by the inhibition product (5).

[0178] At time (tr), the removal of the extractable material occurs. Preferably, this time (tr) takes place within an interval represented by brackets in the diagram. In this interval, the degree of curing is sufficiently high (approximately 80%) to prevent the material removal agents from adhering to surfaces, but not so high as to hinder extraction due to the bonds between the material in the inhibition zone and that of adjacent zones becoming too strong, in particular, to the point where extraction becomes impossible due to the material having fully cured.

[0179] Different types of separation layers (es, es', es") can be used to achieve various complementary technical effects in the invention. In particular, as shown in the curing diagram, separation layers configured with different curing speeds can be used, for example, by varying the amount of photoinitiators present in their composition. For instance, different chemical formulations of the separation layer (es, es', es") can be employed; in particular, a higher concentration of photoinitiators results in faster curing. The thickness of the base layer (cb) can also influence the curing speed of the separation layer (es, es', es") from the moment the base layer (cb) is applied.

[0180] Considering the type of separation layer (es), with a greater number of photoinitiators, the type of separation layer (es') - with a greater slope - could be obtained, while with a smaller number of photoinitiators, the type of separation layer (es”) - with a lower slope - could be obtained.

[0181] According to a first embodiment example shown in the curing diagram for the separation layer (es), the separation layer (es) is configured to fully cure substantially no later than the base layer (cb) fully cures in the inhibition zones (7) and substantially later than it fully cures in the adjacent zones (8).

[0182] According to a second embodiment example shown in the curing diagram for the separation layer (es'), the separation layer (es') is set up to fully cure substantially no later than the base layer (cb) fully cures in the adjacent areas (8).

[0183] According to a third embodiment example shown in the curing diagram for the separation layer (es”), the separation layer (es”) is configured to fully cure substantially later than the base layer (cb) fully cures in said inhibition zones (7).

[0184] In the three embodiments represented in the curing diagram, differential curing radiation acts on the separation layer (es, es', es"), such that, upon removal of the extractable material, it is substantially separated at the interface between the base layer (cb) and the separation layer (es, es', es"). This interface exhibits substantially lower polymerization adhesion in at least one inhibition zone (7) than in the respective adjacent zones (8), due to the differential action of the curing radiation applied to the base layer (cb) on the separation layer (es, es', es"). The curing radiation acting differentially on the base layer (cb), due to the radiation inhibition product (5), also acts differentially on the separation layer (es, es', es") for at least part of the time (td, td', td") during which the separation layer (es, es', es") remains partially cured.

[0185] Comparatively, when the base layer (cb) is applied, the separation layer (es') in the second example is the most cured, and the separation layer (es") in the third example is the least cured of the three, with the separation layer (es) in the first example having an intermediate degree of curing. Consequently, the separation layer (es') provides fewer free radicals for bonding with the base layer (cb) than with the separation layer (es), and the latter has fewer free radicals than the separation layer (es").

[0186] Conversely, since the time intervals (td, td', td") during which the curing radiation acts differentially are different, with the separation layer (es, es', es") being partially cured, the bond with the base layer (cb) formed by the intertwining of the available free radicals is different in the three cases.

[0187] Thus, the separation of the extractable material can be achieved, in particular, with the three types of separation layer (es, es', es"), with which the least adhesion by polymerization is achieved at the interface between the base layer (cb) and the separation layer (es, es', es") in the inhibition zones (7) with respect to their adjacent zones (8).

[0188] If the type of separation layer (es') from the second example is used, when the removable material is removed with a sufficiently high degree of curing, the separation layer (es') is already fully cured and therefore the base layer (cb) can be bonded more strongly to the separation layer (es').

[0189] If the type of separation layer (es”) from the third example is used, when removing the extractable material with a sufficiently high degree of cure, the separation layer (es”) is still partially cured. This further facilitates material extraction due to the difference in the degree of cure between the base layer (cb) and the separation layer (es”). Moreover, if the base layer (cbi) in the inhibition zone (7) is more cured than the separation layer (es”), material extraction can be facilitated even further, for example, with less brushing force.

[0190] Preferably, if the type of separation layer (es) of the first example is used, a balanced technical effect can be achieved, in particular, between an adequate bonding force between base layer (cb) and separation layer (es) while at the same time optimally facilitating the extraction of the material once it is sufficiently cured or solidified.

[0191] Figure 16 schematically shows an example of a texture generation system embodiment (3) according to the invention. In particular, this system embodiment can be used to carry out the procedure depicted in Figure 15.

[0192] According to this embodiment, the texture generation system (1) (3) comprises extension means (32) of a base layer (cb), curing radiation application means (23, 24) configured to act differentially on the base layer (cb), and means for removing extractable material (50, 51) from the base layer (cb).

[0193] Characteristically, the system (1) comprises extension means (31) of a separation layer (es), means for applying curing radiation (22) onto the separation layer (es, es', es") and a controller (70) configured to actuate said means (31, 32; 22, 23, 24; 50, 51) by carrying out a procedure according to the invention.

[0194] The layer spreading means (30, 31, 32) may comprise, for example, as shown in the figure, spreading rollers. The curing radiation application means (20, 21, 22, 23, 24, 25) may comprise, for example, as shown in the figure, UV radiation lamps. The removable material removal means (50, 51) may comprise, for example, as shown in the figure, extraction brushes (51) and / or transfer rollers (50). The substrate transport means (60) may comprise, for example, as shown in the figure, conveyor belts (60) on which the substrates (2) are transported.

[0195] As shown in Figure 16, the substrate (2) on which the texture (3) is generated is transported along the different stations of the system (1) to carry out the procedure by means of substrate transport, for example, as shown in the figure, in the form of a conveyor belt (60).

[0196] First, a decorative layer (cd) is applied to the substrate (2), for example, as shown in the figure, using a single-pass inkjet printer (10). The printer (10) comprises inkjet printheads (11, 12, 13) of different colors and, preferably, lamps (15) for fixing (“pinning”) the deposited print droplets.

[0197] After applying curing radiation to the decorative layer (cd) using a UV lamp (20), the protective layer (cp) is spread onto the substrate (2) using a spreading roller (30). Then, curing radiation is again applied to the protective layer (cp) using a UV lamp (21).

[0198] The separation layer (es) is then spread using a spreading roller (31). Curing radiation is then applied to the separation layer (es) again using a UV lamp (22). The base layer (cb) is then spread over the separation layer (es), also using a spreading roller (32). Curing radiation is then applied to the base layer (cb) again using a UV lamp (23).

[0199] Next, the substrate (2) is subjected to curing radiation that acts differentially on the base layer (cb). For this purpose, the system (1) may comprise, as shown in the figure, a single-pass inhibitor product inkjet printer (40). The printer (40) comprises inhibitor product injection heads (41) and, preferably, pinning lamps (42) for the deposited print droplets.

[0200] Once the radiation inhibition product (5) has been deposited on the base layer (cb), the application of curing radiation on the inhibition product (5) and the base layer (cb), using a UV lamp (24), allows obtaining the radiation inhibition zones (7).

[0201] Then, the cavities (4) of the texture (3) are formed by removing the extractable material from the base layer (cb), which is separated by the interface between the base layer (cb) and the separation layer (es) in the inhibition zones (7). For this purpose, as shown in the figure, a transfer roller (50) can be used first, which facilitates the extraction of the more liquid part of the extractable material, and then an extraction brush (51), which facilitates the extraction of the deeper part of the extractable material.

[0202] Finally, curing radiation is applied, for example, as shown in the figure, using a UV lamp (25), to complete the curing of the final product.

[0203] The system (1) is configured to carry out a procedure according to the invention. Thus, in the context of this specification, it may be understood that any procedural feature described herein can be provided by physical features of the system in the form of suitable means, devices, or elements. Consequently, the effects and technical advantages of the procedure according to the invention also apply to the system.

[0204] In short, as explained in this document, the invention provides a procedure and a system that allows overcoming the limitations of the state of the art, offering additional technical advantages.

[0205] To that end, the invention is not limited to the embodiments presented, but includes all variations, modifications, and combinations included within the scope of the attached claims.

[0206] List of reference signs

[0207] 1 Texture generation system

[0208] 2 Substrate

[0209] 3 Texture

[0210] 4 Cavity

[0211] 5 Radiation inhibition product

[0212] 6 Radiation promotion product

[0213] 7, 7', 7” Radiation inhibition zones

[0214] 8 Zone adjacent to the inhibition zones

[0215] 9 Radiation promotion zone

[0216] 10 Decorative inkjet printer 11, 12, 13 Color printheads

[0217] 15 Color printing fixing radiation lamp

[0218] 20, 21, 22, 23, 24, 25 Curing radiation lamps

[0219] 30 Protective Coating Extension Roller

[0220] 31 Separation layer extension roller

[0221] 32 Base coat spreading roller

[0222] 40 Inkjet printer inhibitor product

[0223] 41 Inhibition Product Printhead

[0224] 42 Inhibition product fixation lamp

[0225] 50 Material Transfer Roller

[0226] 51 Material Extraction Brush

[0227] 60 Substrate transport belt

[0228] 70 Texture generation procedure controller cb, cbl, cbll, cblll Base layers cb1, cb2 Base sublayers es, es', es”, esl, csll, cslll Separation layers pr Reinforcement particles cp Protection layer cd Decoration layer

[0229] The liquid state

[0230] G state gel

[0231] G+ solid gel state

[0232] S solid state cba Base layer in adjacent zones cbi Base layer in inhibition zones td, td', td” Time intervals in which the separation layer is partially cured since differentially applied inhibition curing radiation ted Time interval at which the decoration layer is spread tep Time interval at which the protection layer is spread tes Time interval at which the separation layer is spread teb Time interval at which the base layer is spread tpi Time interval at which the inhibition product is applied tr Time interval at which the removable material is removed

Claims

CLAIMS 1. A texture generation method (3), wherein polymerization curing radiation acts on a base layer (cb), differentially in inhibition zones (7, 7', 7") of curing radiation with respect to adjacent zones (8) lateral to the inhibition zones (7, 7', 7"), the textures (3) comprising cavities (4) formed by the removal of extractable material from the base layer (cb) in the inhibition zones (7, 7', 7"), in which the base layer (cb) exhibits a substantially lower degree of curing than in the respective adjacent zones (8), characterized in that the base layer (cb) extends over a separation layer (es, es', es"), said separation layer (es, es', es") being partially cured by polymerization curing radiation, such that at least one inhibition zone (7) reaches the separation layer (es, es', es") and, on the separation layer (es, es', es"),The curing radiation acts differentially in at least one inhibition zone (7) compared to its adjacent zones (8), so that, when the removable material is removed, it separates substantially at the interface between the base layer (cb) and the separation layer (es, es', es"), with said interface exhibiting substantially less polymerization adhesion in at least one inhibition zone (7) than in its adjacent zones (8).

2. Texture generation method (3), according to the preceding claim, characterized in that the curing radiation that acts differentially on the base layer (cb) acts differentially at the same time on the separation layer (es, es', es"), during at least part of the time (td, td', td") in which the separation layer (es, es', es") is still partially cured.

3. A texture generation method (3), according to one of the preceding claims, characterized in that, prior to spreading the base layer (cb), curing radiation acts differentially on the separation layer (es, es', es") in promotion zones (9) of curing radiation, substantially coinciding with the at least one inhibition zone (7) in said interface, with respect to its adjacent zones (8), in particular, the separation layer (es, es', es") being cured completely, prior to spreading the base layer (cb), selectively in the promotion zones (9) by curing radiation.

4. A texture generation method (3), according to one of the preceding claims, characterized in that, upon removal of the removable material, the extracted material exhibits a sufficiently high degree of curing to substantially prevent its adhesion to surfaces of means for removing the removable material.

5. A texture generation method (3), according to any of the preceding claims, characterized in that the separation layer (es, es', es") is configured so that the separation layer (es) cures fully substantially no later than the base layer (cb) cures fully in said inhibition zones (7) and substantially later than it cures fully in the adjacent zones (8), or the separation layer (es') cures fully substantially no later than the base layer (cb) cures fully in the adjacent zones (8), or the separation layer (es") cures fully substantially later than the base layer (cb) cures fully in said inhibition zones (7).

6. Texture generation method (3), according to one of the preceding claims, characterized in that the base layer (cb) comprises a plurality of base sublayers (cb1, cb2) that extend over one another.

7. A texture generation method (3), according to one of the preceding claims, characterized in that a plurality of base layer (cbl, cbll, cblll) and separation layer (esl, csll, cslll) pairs are extended over one another, such that said inhibition zones (7) reach respective separation layers (esl, csll, cslll).

8. Texture generation method (3), according to one of the preceding claims, characterized in that the separation layer (es) incorporates reinforcing particles (pr) and / or thickening agents to increase the cohesion of the separation layer (es) when spreading the base layer (cb).

9. A texture generation method (3) according to any of the preceding claims, characterized in that it comprises depositing a curing radiation inhibition product selectively onto the inhibition zones (7) and / or onto the zones adjacent (8) to the promotion zones (9), and / or a curing radiation promotion product (6) selectively onto the promotion zones (9) and / or the zones adjacent (8) to the inhibition zones (7).

10. A digital texture printing process according to claim 9, characterized in that the curing radiation inhibition product deposited on the inhibition zones further comprises a curing inhibition agent and / or a glass transition temperature (Tg) lowering agent, and / or is configured to cure by curing radiation, be immiscible or partially miscible in the base layer and / or sublimate.

11. A texture generation method (3), according to one of the preceding claims, characterized in that, prior to spreading the base layer (cb), on the separation layer (es, es', es"), in areas substantially coinciding with the at least one inhibition zone (7), a polymerization barrier product is deposited by curing radiation, comprising a curing inhibition agent and / or a curing inert agent, in particular, the polymerization barrier product being at the same time a promotion product (6).

12. Texture generation method (3), according to any one of claims 9 to 11, characterized in that the curing radiation inhibition product, the curing radiation promotion product (6) and / or the polymerization barrier product are deposited in the form of printing droplets (5) by inkjet printing.

13. Texture generation procedure (3), according to the previous claim, characterized in that it comprises selecting print drop volumes per print point and / or separation of print points to obtain cavities (4) with predetermined depth levels.

14. Texture generation method (3), according to one of the preceding claims, characterized in that the thickness of the base layer (cb) is greater than or equal to 100 microns, preferably 150 microns, more preferably 200 microns.

15. Texture generation system (3), comprising extension means (32) of a base layer (cb), curing radiation application means (23, 24) configured to act differentially on the base layer (cb) and means for removing removable material (50, 51) from the base layer (cb), characterized in that it comprises extending means (31) of a separation layer (es), curing radiation application means (22) on the separation layer (es) and a controller (70) configured to actuate said means (31, 32; 22, 23, 24; 50, 51) by carrying out a procedure according to any one of claims 1 to 14.

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