Printing method for three-dimensional plate with clear wood grain effect and use

Abstract

The present invention relates to the field of plate production, and in particular to a printing method for a three-dimensional plate with a clear wood grain effect and a use. The method comprises: acquiring a first ink input value-first ink output value change curve of a first printing device and at least one second ink output value matched with the first ink input value-first ink output value change curve, so as to obtain at least one first ink input value-second ink output value change curve, determining the inkjet amount of a first ink and the inkjet amount of a second ink, and then allocating the inkjet amount of the first ink and the inkjet amount of the second ink to the first printing device, so as to output on the surface of a plate a wood grain at the bottom layer. According to the present application, the inkjet amount of different inks is accurately determined on the basis of characteristic curves of the inks by means of a "curve matching" method, so as to control the distribution of different inks on the surface of a plate. By matching curves of different ink output values, accurate inkjet amount allocation can be carried out on the surfaces of wood grains at the bottom layer, so that the definition and fineness of the wood grains are ensured.

Description

Printing method and application of three-dimensional sheet material with clear wood grain effect Technical Field

[0001] The present invention relates to the field of board production, and in particular to a printing method and application of a three-dimensional board with a clear wood grain effect. Background Art

[0002] Solid wood flooring, a flooring material made from natural wood, offers an elegant appearance and durability. Solid wood flooring can enhance the natural atmosphere of any home, creating a home environment that connects with nature and allows people to experience its charm. Furthermore, due to the wide variety of solid wood flooring options, different wood floors offer varying textures and colors, showcasing a natural beauty and uniqueness. Consumers can choose the right solid wood flooring pattern based on their preferences and decorating style, showcasing their individuality and taste. This allows consumers to meet their diverse decorating needs and personalization needs, creating a unique interior design.

[0003] However, as environmental protection becomes increasingly stringent, attitudes toward solid wood flooring are also evolving. For example, solid wood flooring is manufactured from logs, requiring a significant amount of wood as raw material. If the acquisition of this wood is not effectively managed and regulated, it can lead to over-logging and damage to forest resources, posing a threat to the balance and conservation of forest ecosystems.

[0004] To reduce the impact of solid wood flooring on forest resources, promote sustainable forestry management, and advocate for forest conservation and sustainable development, artificial wood flooring has gradually gained popularity in the market. Artificial flooring is typically made from materials such as wood fiber and recycled plastic, conserving natural wood resources and reducing the pressure to clear virgin forests. Furthermore, artificial flooring is typically produced on industrial production lines, effectively utilizing raw materials such as wood and plastic, reducing waste. Finally, artificial flooring is manufactured with high homogeneity and consistent dimensions, reducing waste and resource consumption.

[0005] Currently, common artificial flooring options include rubber-plastic flooring, wood-plastic flooring, and stone-plastic flooring. Each has its own unique characteristics in appearance, performance, and applicable environments. As artificial flooring becomes increasingly diverse in production processes and material options, its environmental performance and lifespan are also constantly improving, meeting the diverse needs of consumers in renovation and decoration.

[0006] However, existing artificial board flooring still differs significantly from solid wood flooring in appearance and feel, ultimately failing to achieve a texture similar to natural wood. Therefore, to bridge the gap between artificial board flooring and solid wood flooring, researchers have devoted extensive research and development efforts to develop products based on artificial boards or non-wood boards that resemble the visual and tactile qualities of natural wood. These boards are expected to offer improved performance and durability, thus meeting consumer demand for high-quality, low-maintenance, and low-cost products. Furthermore, these products, which resemble natural wood, can reduce reliance on natural resources, thereby protecting the environment and promoting sustainable development.

[0007] For example, in order to obtain a texture similar to natural wood on the surface of artificial boards or non-wood boards, manufacturers usually adopt the following methods:

[0008] 1. Printing technology: Use high-resolution printing technology to print the natural wood texture pattern onto the surface of the board;

[0009] 2. Veneer: A thin wood surface is glued to the surface of the board to imitate the look and texture of natural wood;

[0010] 3. Coating technology: Through a special coating process, a texture and color similar to natural wood are formed on the surface of the board.

[0011] While these methods can mimic the look and feel of natural wood to a certain extent, they also have certain drawbacks. For example, printing technology cannot fully replicate the texture of natural wood; thin wood veneers are easily affected by moisture and crack; and coating technology may have adverse effects on the environment.

[0012] Patent publication number CN 101659073 B discloses a wood grain treatment process for waterproof flooring substrates. This process involves printing simulated wood grain on the surface of a wood-plastic flooring material and then adding a wear-resistant layer over the simulated wood grain. This protects the wood grain pattern and maintains the wood grain texture over time. However, this type of board, which is simply printed with a two-dimensional graphic, no longer meets people's demand for a more realistic visual and tactile experience.

[0013] Therefore, forming three-dimensional wood grain on the surface of a board material that corresponds to a two-dimensional plane image and has a touch that is more similar to wood is currently a common concern in the art.

[0014] In the prior art, a variety of different technical solutions have been proposed to form a three-dimensional structure on the surface of a substrate. Conventional methods generally include molding, upward stacking, and downward indentation. For specific technical solutions, please refer to the following patents.

[0015] For example, patent publication number CN115027117A discloses an enhanced wood-grain flooring, comprising a foam core with a shell and attachments distributed on the shell surface. The shell is formed from a first-color resin, and the attachments are formed from a second-color resin. During the manufacturing process, the core is embossed using an embossing roller, pressing portions of the second-color resin layer below the shell surface, giving the shell and second-color resin layers a combined wood-grain texture.

[0016] Patent publication number CN 112455110 A discloses a process for producing wooden flooring using inkjet printing. This patent enables the formation of convex three-dimensional wood grain on the surface of a printed pattern by continuously printing additive ink on the surface of the printed pattern.

[0017] Patent publication number CN 112739463 A discloses a new method and apparatus for producing a surface structure, comprising the following steps: A) applying resin A to the surface of a material; B) applying liquid B to at least a portion of the resin A when the resin A is liquid or partially solidified; C) polymerizing the resin A and the liquid B separately; and D) removing the polymerized liquid B.

[0018] Patent publication number CN 112996649 A discloses a method for manufacturing a three-dimensional structure on the surface of a flat substrate, the resulting substrate, and an apparatus for producing the substrate according to the method. A material for forming wood grain joints is previously dripped onto the surface of the substrate, and then a curable resin is applied to areas of the substrate surface not covered with the material for forming wood grain joints. The resin is then cured and the material for forming wood grain joints is removed, thereby forming wood grain joints in the cured resin.

[0019] However, after forming the three-dimensional structure on the substrate surface, researchers discovered that the wood grain on some boards was blurred and had mixed colors. No specific solution has been proposed in the prior art to address this technical issue.

[0020] Summary of the Invention

[0021] The present invention aims to overcome the problems of blurred wood grain and mottled color in the preparation process of boards containing three-dimensional wood grain in the prior art, and therefore provides a printing method for three-dimensional boards with clear wood grain effect to overcome the above-mentioned shortcomings.

[0022] To achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions:

[0023] In a first aspect, the present invention provides a method for printing a three-dimensional plate material with a clear wood grain effect, which comprises at least the following steps:

[0024] - obtaining a first ink input value-first ink output value variation curve of a first printing device;

[0025] - obtaining at least one second ink output value of the first printing device that matches the first ink input value-first ink output value variation curve, thereby obtaining at least one first ink input value-second ink output value variation curve;

[0026] - determining the ejection amounts of the first ink and the second ink based on the first ink input value-first ink output value variation curve and the first ink input value-second ink output value variation curve;

[0027] - allocating the inkjet amounts of the first ink and the second ink determined based on the first ink input value-first ink output value variation curve and the first ink input value-second ink output value variation curve to the first printing device, thereby outputting the underlying wood grain on the surface of the board;

[0028] -A three-dimensional wood grain that matches the shape of the underlying wood grain is printed on the surface of the underlying wood grain using a second printing device to obtain a three-dimensional board with a clear wood grain effect.

[0029] The inventors of the present application discovered during the actual production process that the problem of blurring and discoloration of the wood grain on the surface of the three-dimensional plate may be caused by: (1) during the printing process of the two-dimensional wood grain, due to insufficient ink purity, there is a certain gap between the value of the ink input from the printing device and the final output value of the ink, resulting in the inability to achieve good color accuracy; (2) during the process of printing the three-dimensional wood grain on the surface of the two-dimensional wood grain, since the wear-resistant resin used to form the three-dimensional wood grain presents a certain arc state, the three-dimensional wood grain will present a certain convex lens state, which has a certain magnifying effect on the printing points of the three-dimensional wood grain, thereby magnifying the originally imperceptible blur and discoloration defects.

[0030] To overcome the problems of blurred wood grain and discoloration encountered in existing technologies, the inventors of this application discovered that, due to limitations in ink quality and color gamut, a single ink alone cannot achieve the desired color when printing two-dimensional wood grain. Therefore, it is often necessary to add other colors during the printing process, using multiple colors of ink dots to overlay and print, to ensure that the printed color is consistent with the desired color. However, while existing color overprinting techniques can predict the final result within a certain range, they cannot always achieve the optimal color output effect.

[0031] In this application, in order to achieve more realistic and higher-definition two-dimensional wood grain printing, the inventor first selects a main color close to the desired two-dimensional wood grain color (i.e., the first ink described in this application) during the ink selection process, and then uses some other color inks (i.e., the second ink in this application) to assist in obtaining a state closer to the ideal wood grain color.

[0032] However, in actual operation, we found that the auxiliary color can only ensure that the final two-dimensional wood grain has higher clarity and fidelity when it is within a small range. When the amount of auxiliary color used is small, the saturation of the final output color may decrease, resulting in unclearness. When the amount of auxiliary color used is too much, the final output color will be accompanied by a phenomenon of mixed colors. Therefore, the key point of the present invention is how to determine the usage ratio between the auxiliary color (i.e., the second ink in this application) and the main color (i.e., the first ink described in this application) so that the final color obtained is clearer and more realistic.

[0033] When considering how to print clear wood grain effects on 3D panels, the first challenge is how to effectively control the ink jet volume to ensure the clarity and quality of the underlying wood grain. This patent addresses this challenge through a series of innovative steps and methods.

[0034] First, this patent proposes a step for obtaining a first ink input value-first ink output value variation curve for a first printing device. This means that we first calibrate the input and output states of the first ink to determine the first printing device used for printing two-dimensional wood grain and the difference between the target printing value and the actual printing value of the first ink used. Through multiple calibrations, we ultimately obtain different first ink input value-first ink output value variation curves, which lay the foundation for subsequent inkjet volume control.

[0035] Secondly, at least one second ink is matched based on the points on the first ink input value-first ink output value variation curve, thereby obtaining multiple optimal output values ​​of different second inks that match the first ink input value-first ink output value variation curve. After multiple matches, the first ink input value-second ink output value variation curve can be obtained. At this time, the point on the first ink input value-second ink output value variation curve is the second ink output value that can help the first ink achieve the best display effect. Therefore, the present application ultimately determines the inkjet volume of different inks by comparing the curves of different ink output values. This "curve matching" method provides a new approach to controlling the ink jetting volume.

[0036] Next, based on the first ink input value-first ink output value change curve and the first ink input value-second ink output value change curve, this patent proposes a method for determining the inkjet volume of the first ink and the second ink. This means that we can accurately determine the inkjet volume of different inks based on the ink characteristic curve, thereby controlling the distribution of different inks on the surface of the board. Therefore, by matching the curves of different ink output values, this application can accurately distribute the ink jet volume on the underlying wood grain surface to ensure the clarity and fineness of the wood grain. This personalized ink jet volume distribution can better adapt to the printing requirements of different wood grain shapes and textures, thereby achieving a clearer and more realistic effect.

[0037] Finally, by distributing the ink jetting amounts determined based on these curves to the printing devices, the underlying wood grain is output on the surface of the underlying wood grain. Based on the underlying wood grain, a second printing device prints a three-dimensional wood grain that matches the shape of the underlying wood grain, resulting in a three-dimensional board with a clear wood grain effect.

[0038] At this time, when the first ink and the second ink are at the optimal output value, the final wood grain effect is the state with the maximum saturation value or the maximum blackness value. Even under the magnifying effect of the convex lens of the wear-resistant resin, the problems of blurring and discoloration can still be avoided.

[0039] Therefore, compared to the existing technology, the solution in this application abandons the traditional experience-based color matching scheme, and can always ensure that the final two-dimensional wood grain has a clearer and more realistic effect, thereby effectively avoiding the blurring of the wood grain and the interference of various colors, making the final artificial board flooring have a more excellent visual effect. This application uses the change curve of the ink to determine the ink injection amount, thereby achieving clear printing of the wood grain. Through this personalized ink injection amount distribution technology, this patent provides a new solution for the printing of three-dimensional board materials, making the underlying wood grain clearer and more realistic, greatly improving the quality and precision of the printing effect.

[0040] Preferably, when the first ink is achromatic ink, the output value of the second ink is the second ink output value corresponding to the maximum blackness value after the first ink and the second ink are superimposed;

[0041] When the first ink is colored ink, the output value of the second ink is the second ink output value corresponding to the maximum saturation value after the first ink and the second ink are superimposed.

[0042] The advantage of this approach in this application is that it provides customized adjustments for different ink types to achieve better printing results. This color attribute-based output value selection method optimizes the output value of the achromatic ink and the colored ink separately, so that the output value of the second ink and the superposition effect of the first ink are optimal, thus ensuring the best printing and visual performance.

[0043] For achromatic ink, selecting the second ink output value with the largest blackness value after superposition can ensure that when printing the underlying wood grain, the ink superposition effect is clearer and more vivid, thereby making the depth and shallowness of the underlying wood grain clearer and improving the visual quality of the printing effect.

[0044] For colored inks, selecting the second ink output value with the largest saturation value after superposition can ensure that the color vividness and purity are optimally guaranteed when printing the underlying wood grain, making the color of the underlying wood grain more full and rich, and improving the visual appeal of the printing effect.

[0045] Therefore, the color attribute-based output value selection method allows the second ink to be better superimposed with the first ink, ensuring optimal clarity and color rendering when printing the underlying wood grain. This method provides more detailed and personalized ink adjustment for printing the underlying wood grain, resulting in a clearer, more realistic, and more vivid wood grain effect on the final three-dimensional board.

[0046] Preferably, the achromatic ink is black ink;

[0047] The colored ink is a combination of at least one or more of cyan ink, magenta ink, and yellow ink.

[0048] As an advantage, the method further comprises the following steps:

[0049] - The step of establishing a bottom wood grain printing dataset and a three-dimensional wood grain printing dataset; wherein,

[0050] The bottom wood grain printing dataset includes a bottom wood grain shape dataset;

[0051] The three-dimensional wood grain printing data set includes a three-dimensional wood grain shape data subset corresponding to the bottom wood grain shape data set and a three-dimensional wood grain printing depth data subset matching the three-dimensional wood grain shape data subset;

[0052] - Simultaneously allocating the bottom wood grain shape dataset and the inkjet amounts of the first ink and the second ink to the first printing device, thereby outputting the bottom wood grain on the surface of the board;

[0053] - Assigning the three-dimensional wood grain printing data set to the second printing device, so that printing is performed on the bottom wood grain surface by the second printing device to obtain a three-dimensional wood grain that matches the shape of the bottom wood grain, and the height or depth of the three-dimensional wood grain corresponds to the three-dimensional wood grain printing depth data subset.

[0054] After extensive and in-depth research on natural wood panels, the applicant discovered that the color, grain shape, and three-dimensional structure of natural wood materials vary to varying degrees depending on the wood species and growth environment. This results in individual natural wood panels exhibiting varying visual and tactile effects. Based on this discovery, in order to create a more realistic three-dimensional wood grain on the surface of artificial panels, it is necessary to consider the visual similarity between the two-dimensional structure and the natural wood grain, as well as the visual and tactile similarity between the three-dimensional structure and the natural wood grain.

[0055] Numerous methods exist for creating a two-dimensional base wood grain layer on the surface of artificial boards, including printing and high-precision printing techniques. These techniques can effectively reproduce the color and grain patterns of authentic natural wood materials, making these patterns visually closer to natural wood grain. However, achieving a three-dimensional wood grain pattern above the base wood grain layer that matches the underlying wood grain layer and provides a feel similar to natural wood grain remains a challenge in this field.

[0056] Generally speaking, in order to form three-dimensional wood grain on the surface of a board, it is first necessary to make a shape reference for the two-dimensional underlying wood grain layer to be printed, and use the two-dimensional underlying wood grain layer to model the board to be printed, so that the printing device can print according to the established three-dimensional model, thereby obtaining a three-dimensional wood grain that corresponds to the target model in the shape of the wood grain and the length, width and depth of the wood grain. Therefore, in this type of model, a three-dimensional model can only correspond to a board with a specific two-dimensional underlying wood grain layer. If any variable that forms the board needs to be changed individually, the model needs to be redrawn and adjusted, resulting in the above-mentioned method of forming three-dimensional wood grain being less flexible and difficult to adapt to the board in a short period of time. At the same time, the production cost is relatively high. Therefore, the product lines of companies that use this traditional method to prepare boards with three-dimensional wood grain on the surface are usually relatively single, and it is difficult to meet the needs of customization according to customer requirements.

[0057] To overcome the deficiencies in the aforementioned prior art, the applicants conducted further in-depth research on both planar underlying wood grain layers and three-dimensional wood grain patterns. After studying the planar underlying wood grain layer, the applicants discovered that the elements that form the underlying wood grain layer typically include the color and shape of the wood grain. Simply by combining the color and shape of the wood grain, a wood grain pattern that matches different wood materials can be formed. Furthermore, after conducting in-depth research on three-dimensional wood grain patterns, the applicants discovered that the elements that form the three-dimensional wood grain typically include the shape of the wood grain and the corresponding depths of different wood grain shapes. Combining the wood grain shape with different depth information can create a three-dimensional wood grain pattern that more closely resembles a natural wood grain structure.

[0058] Therefore, based on the above findings, compared with the prior art, the present invention analyzes and processes the information containing natural wood grain, thereby classifying and regularizing the formation parameters related to natural wood grain, thereby obtaining a bottom wood grain printing data set and a three-dimensional wood grain printing data set. Among them, the bottom wood grain printing data set records the data information used to control the formation of the bottom wood grain layer, while the three-dimensional wood grain printing data set records the data information used to control the formation of three-dimensional wood grain. In addition, the three-dimensional wood grain printing data set in this application contains a bottom wood grain shape data set corresponding to the bottom wood grain printing data set. Therefore, when the relevant information for printing the bottom wood grain layer is determined, the three-dimensional wood grain shape data that matches the shape and size of the bottom wood grain layer can be selected from the bottom wood grain shape data set, thereby effectively achieving the correspondence between the shape and position of the bottom wood grain layer and the top three-dimensional wood grain, avoiding the problem of inaccurate alignment between the two.

[0059] In addition, after the three-dimensional wood grain shape is determined, by calling the three-dimensional wood grain printing depth data subset, one or more wood grain depths are assigned to each wood grain of different shapes, so that three-dimensional wood grains of different shapes can have different corresponding depths, and the depth can change with the three-dimensional wood grain of different shapes, so as to be more adapted to the structure of natural wood grain, so that the obtained three-dimensional wood grain has a higher similarity with the natural wood grain.

[0060] Therefore, through the method described in this application, three-dimensional wood grain similar to that of natural wood boards can be obtained on the surface of artificial or non-wood boards, and by digitizing the wood grain information, the bottom wood grain layer and the three-dimensional wood grain located above the bottom wood grain layer can be strictly corresponded during the printing process, thereby overcoming the problem of difficulty in "matching patterns" in the existing technology.

[0061] Finally, the method in the present application also has the advantage of high flexibility. Compared with the existing technology, the three-dimensional wood grain in the present application does not require three-dimensional modeling of a single underlying wood grain layer. It only needs to analyze the wood grain shape contained in the underlying wood grain layer, and obtain it by retrieving it from the three-dimensional wood grain printing shape data subset of the three-dimensional wood grain printing data set. The shape data recorded in the three-dimensional wood grain printing shape data subset is matched with the depth data recorded in the three-dimensional wood grain printing depth data subset, thereby creating a three-dimensional wood grain that is closer to natural wood grain, effectively simplifying the construction process of the three-dimensional wood grain, enabling manufacturers to customize the production of products according to customer needs, expanding the richness of the company's product line, effectively reducing production costs and improving production efficiency.

[0062] Preferably, the underlying wood grain shape data set includes multiple sets of plane wood grain printing coordinate data for printing wood grain shapes, each plane wood grain printing coordinate data corresponds to the underlying wood grain color data, and the first printing device prints based on the plane wood grain printing coordinate data and the underlying wood grain color data, and each plane wood grain printing coordinate data corresponds to an underlying wood grain printing route.

[0063] The underlying wood grain shape data set in the present invention includes multiple planar wood grain printing coordinate data for printing wood grain. This data also corresponds to color information, and this color information should be different from the wood grain base color to distinguish the planar wood grain from the base color, allowing the wood grain to be displayed on the base color surface. Furthermore, because the planar wood grain printing coordinate data records the coordinates of each point that makes up the wood grain, the first printing device can print and output the wood grain based on this planar wood grain printing coordinate data.

[0064] Preferably, the three-dimensional wood grain shape data subset includes multiple two-dimensional three-dimensional wood grain printing coordinate data for printing wood grain, each three-dimensional wood grain shape data subset corresponds to a three-dimensional wood grain printing route, and the multiple three-dimensional wood grain printing routes respectively overlap with the multiple bottom wood grain printing routes on the two-dimensional plane.

[0065] The three-dimensional wood grain printing coordinate data contained in the three-dimensional wood grain printing shape data subset in the present application also records the plane coordinates of each point that constitutes the three-dimensional wood grain, and can correspond to the coordinate information recorded in the underlying wood grain printing shape data subset in the underlying wood grain printing data set on a two-dimensional plane. Therefore, it is only necessary to determine the three-dimensional wood grain shape data subset and the three-dimensional wood grain printing depth data subset that matches the three-dimensional wood grain shape data subset before the second printing device can output and print along the established printing line, thereby completing the pattern matching process between the three-dimensional wood grain and the underlying wood grain layer.

[0066] Preferably, the three-dimensional wood grain printing depth data subset includes printing depth data of each three-dimensional wood grain printing coordinate data.

[0067] Preferably, the step of printing the three-dimensional wood grain includes the following steps:

[0068] - outputting a wood grain precursor liquid using the three-dimensional wood grain printing data set through a second printing device, thereby depositing a wood grain precursor that matches the shape of the underlying wood grain on the surface of the underlying wood grain;

[0069] - Applying energy to the wood grain precursor so that the wood grain precursor is solidified to obtain three-dimensional wood grain.

[0070] As described in the background, there are various methods for preparing a three-dimensional wood grain layer. In some preferred embodiments of the present invention, a stacking method can be employed to form a three-dimensional wood grain layer on the surface of an underlying wood grain layer. In this method, a curable wood grain precursor liquid can be continuously stacked upward to form a wood grain precursor with varying depths, lengths, and widths. In this case, the wood grain precursor only needs to be cured to form a three-dimensional wood grain layer. The curing method of the wood grain precursor depends on the physicochemical properties of the applied wood grain precursor liquid. If the wood grain precursor liquid contains a thermosetting resin, thermal curing can be used during the curing process. If the wood grain precursor liquid contains a photocatalytic resin, curing of the wood grain precursor can be initiated by simply irradiating the wood grain precursor with ultraviolet light in the presence of a photoinitiator. Generally speaking, photocuring offers higher curing efficiency, thereby effectively improving the efficiency of forming a three-dimensional wood grain layer.

[0071] Preferably, the wood grain precursor liquid includes at least a photocatalytic resin and a photoinitiator for initiating polymerization of the photocatalytic resin.

[0072] Preferably, the photocatalytic resin contained in the wood grain precursor liquid includes acrylic resin, epoxy resin or other photocurable resin.

[0073] Preferably, the photocatalytic resin includes any one or more combinations of unsaturated polyester, epoxy resin, acrylic resin, acrylic modified polyurethane resin, acrylic modified silicone resin, acrylic modified epoxy resin, water-based epoxy acrylate, water-based polyurethane acrylate, and water-based polyester acrylate.

[0074] Preferably, the photoinitiator includes any one of a free radical polymerization initiator, a cationic polymerization initiator, an energy transfer initiator, and an ion reaction initiator.

[0075] Preferably, the wood grain precursor liquid at least includes a thermosetting resin and a curing agent for curing the thermosetting resin.

[0076] Preferably, the thermosetting resin includes one or more combinations of epoxy resin, phenolic resin, melamine formaldehyde resin, furan resin, unsaturated polyester resin, silicone resin, and polybutadiene resin.

[0077] Preferably, the bottom wood grain surface is evenly coated with a three-dimensional base material layer by means of a coating tool, and the wood grain precursor is deposited on the surface of the three-dimensional base material layer.

[0078] Preferably, the step of printing the three-dimensional wood grain includes the following steps:

[0079] - applying a curable liquid resin on the bottom wood grain layer by means of a coating tool, thereby forming a liquid resin layer;

[0080] - outputting a wood grain precursor liquid on a surface of the liquid resin layer using the three-dimensional wood grain printing dataset via a second printing device, so that the wood grain precursor liquid and / or at least a portion of the liquid resin mixed with the wood grain precursor liquid and / or at least a portion of the liquid resin covered by the wood grain precursor liquid forms a wood grain precursor;

[0081] - applying energy to the liquid resin layer to cure the liquid resin layer, so that the liquid resin except the wood grain precursor is cured;

[0082] - A step of removing the wood grain precursor, thereby obtaining three-dimensional wood grain.

[0083] As mentioned above, in addition to the upward stacking method mentioned above, the formation of three-dimensional wood grain layers also includes a downward inward method. Compared with the upward stacking method, the downward inward method creates a texture with controllable width and greater depth, thus creating a stronger three-dimensional effect. Furthermore, the wood grain does not deform during the printing process, resulting in higher printing precision.

[0084] The prior art has adopted the step of applying wood grain precursor liquid to an incompletely cured resin layer. However, from the actual test results, due to the high viscosity of the incompletely cured resin layer itself, it is difficult for the wood grain precursor liquid to enter the resin layer. This brings the following problems: (1) The depth of the wood grain precursor liquid entering the resin layer is low, resulting in a low depth of the final wood grain, making the three-dimensional effect of the overall three-dimensional wood grain layer poor; (2) Due to the high viscosity of the incompletely cured resin layer, the wood grain precursor liquid is more likely to accumulate on the surface of the incompletely cured resin layer after application, making it easier for the wood grain precursor liquid to diffuse on the surface of the resin layer, making it difficult for the shape and width of the final wood grain to match the underlying wood grain layer, thereby causing the problem of misalignment; (3) The incompletely cured resin layer has weak fluidity, so it is difficult to blend with the wood grain precursor liquid in a short time, resulting in the formation of The edges of the three-dimensional wood grain layer are more blurred and not sharp, which is obviously different from the structure of natural wood grain; (4) Since the viscosity of the incompletely cured resin layer is relatively high, even after it is mixed with the wood grain precursor liquid, the viscosity of the obtained wood grain precursor is also relatively high. Although the wood grain precursor cannot be completely cured in the subsequent curing process, its viscosity can still be improved to a certain extent. Therefore, these high-viscosity wood grain precursors are difficult to be removed in the subsequent mechanical removal process, so there will often be a certain amount of residue, which further leads to the problem of unclear and blurred texture of the wood grain, which further widens the gap between its texture and the actual natural wood material.

[0085] Therefore, in addition to adopting a pretreatment step in the preparation process, the present invention also adopts a technical solution of applying the wood grain precursor liquid directly to the surface of the uncured liquid resin during the pretreatment step. Compared with applying the wood grain precursor liquid to the semi-cured resin layer, by changing this step, it can bring the following beneficial effects: (1) Since the uncured liquid resin itself has a low viscosity and good fluidity, the wood grain precursor liquid can smoothly penetrate downward into the uncured liquid resin after being applied to the uncured liquid resin, thereby greatly improving the depth of the prepared wood grain and effectively improving the three-dimensional effect of the three-dimensional wood grain layer. (2) At the same time, since the wood grain precursor liquid can penetrate into the interior of the uncured liquid resin, the wood grain precursor liquid is prevented from diffusing on the surface of the uncured liquid resin, so that the shape and width of the wood grain formed can match the ink layer below, thereby effectively improving the accuracy of the pattern. (3) Since the uncured liquid resin and the wood grain precursor liquid have a good mixing effect, the edges of the wood grain precursor liquid or the wood grain precursor liquid mixed with the uncured liquid resin are more neat and sharp, so the prepared three-dimensional wood grain layer is closer to the natural wood grain. (4) Since the wood grain precursor liquid or the wood grain precursor liquid mixed with the uncured liquid resin still has a low viscosity after curing, it is easier to remove after curing, and no residue will be left after removing the wood grain precursor, so the formed wood grain is cleaner and has sharper edges.

[0086] Preferably, the step (S.3) is followed by a pretreatment step, the pretreatment step comprising: covering at least a portion of the surface above the underlying wood grain layer with a curable liquid resin, and curing at least a portion of the curable liquid resin on the surface of the underlying wood grain layer to form a three-dimensional wood grain bottom layer.

[0087] In the conventional process of creating three-dimensional wood grain using the downward indentation method, the process of removing the wood grain precursor to obtain the three-dimensional wood grain layer will partially expose the underlying wood grain layer. This exposed underlying wood grain layer is easily worn or even peeled off by external forces. Therefore, when mechanically removing the wood grain precursor, the depth of the downward removal must be considered to prevent wear of the underlying wood grain layer, which makes it difficult to increase the depth of the three-dimensional wood grain layer.

[0088] During the process of preparing the three-dimensional structure, the present invention first covers the surface of the underlying wood grain layer with a three-dimensional wood grain base layer obtained by curing a curable liquid resin. A further three-dimensional wood grain layer is then formed on the surface of the three-dimensional wood grain base layer. Due to the presence of the three-dimensional wood grain base layer, the underlying wood grain layer is not exposed during the process of removing the wood grain precursor and forming the three-dimensional wood grain layer. Instead, it is covered by the three-dimensional wood grain base layer, thus preventing the underlying wood grain layer from being worn or peeled off due to external forces. Therefore, the mechanical removal of the wood grain precursor allows for maximum downward excavation, ensuring that the depth of the three-dimensional wood grain layer is effectively increased.

[0089] In addition, in order to make the board containing three-dimensional wood grain prepared by the present invention obtain a texture close to that of natural wood, in addition to considering the wear of the bottom wood grain layer and the depth of the three-dimensional wood grain layer, it is also necessary to consider the correspondence between the bottom bottom wood grain layer and the upper three-dimensional wood grain layer, that is, the problem of alignment between the two. Regarding the alignment problem, the applicant found that the following factors can cause the alignment defect between the bottom wood grain layer and the upper three-dimensional wood grain layer: (1) During the preparation process of the upper three-dimensional wood grain layer, the three-dimensional wood grain layer or the bottom wood grain layer is deformed due to the shrinkage of the curable liquid resin material itself during the curing process; (2) During the preparation process of the three-dimensional wood grain layer, the compatibility between the wood grain precursor liquid and the curable liquid resin is insufficient, resulting in the depth, width and edge shape of the three-dimensional wood grain layer not being consistent with expectations. The applicant found that only after considering the above two factors at the same time can a texture close to that of natural wood be truly obtained.

[0090] Regarding the influencing factor (1), the applicant found that during the curing process of the curable liquid resin, since the energy (UV or heat) used to cure the curable liquid resin is usually input from the top of the liquid resin, the liquid resin at the top will cure first, while the liquid resin at the bottom will cure later. Since the liquid resin often undergoes a certain volume shrinkage during the curing process, a certain internal stress will be generated. These internal stresses will be superimposed downward, thus reaching a maximum value at the bottom of the liquid resin. If the liquid resin is in direct contact with the bottom wood grain layer at this time, once the maximum internal stress is greater than the bonding force between the bottom wood grain layer and the board surface, it will cause the bottom wood grain layer and the board surface to slip, and then make it difficult for the bottom wood grain layer at the bottom to correspond to the three-dimensional wood grain at the top, thereby causing the problem of misalignment, which seriously affects the visual effect of the board. In addition, when the amount of liquid resin applied above the bottom wood grain layer is large, the bottom wood grain layer and the board surface may even peel off, which seriously reduces the product yield.

[0091] Therefore, in order to overcome the above problems, the present invention first covers at least a portion of the surface of the bottom wood grain layer with liquid resin and solidifies this portion of liquid resin to form a wood grain bottom layer. Since the amount of this portion of liquid resin used is small at this time, the internal stress generated after solidification is weak and will not affect the bottom wood grain layer and the surface of the board.

[0092] Because the liquid resin used to form the three-dimensional wood-grain layer is further coated on top of the wood-grain base layer and then cured to form the three-dimensional wood-grain layer, the affinity and adhesion between the wood-grain base layer and the three-dimensional wood-grain layer are strong, so slippage and peeling between the two will not occur. Furthermore, because the wood-grain base layer has high mechanical strength after curing, the internal stress generated by the three-dimensional wood-grain layer during curing is not sufficient to cause deformation of the wood-grain base layer, and thus the internal stress generated by the three-dimensional wood-grain layer during curing will not be transmitted to the underlying wood-grain layer located below the wood-grain base layer. Therefore, by adding this pretreatment step, it is possible to effectively prevent the problem of misalignment between the three-dimensional wood-grain layer and the underlying wood-grain layer during subsequent production.

[0093] Preferably, the wood grain precursor liquid contains at least a polymerization inhibitor for preventing or delaying polymerization of the curable liquid resin.

[0094] Preferably, after the three-dimensional wood grain is prepared, the method further includes covering at least a portion of the surface of the three-dimensional wood grain layer with a topcoat and curing the topcoat layer.

[0095] In a second aspect, the present invention further provides a three-dimensional plate material, which is prepared by the method described above.

[0096] In a third aspect, the present invention further provides the use of the three-dimensional plate material as described above in floors, decorative wall panels or ceiling panels.

[0097] Therefore, the present invention has the following beneficial effects:

[0098] (1) This application uses a "curve matching" method to accurately determine the inkjet volume of different inks based on the ink's characteristic curve, thereby controlling the distribution of different inks on the board surface. By matching the curves of different ink output values, accurate ink jet volume distribution can be performed on the underlying wood grain surface to ensure the clarity and fineness of the wood grain. This personalized ink jet volume distribution can better adapt to the printing requirements of different wood grain shapes and textures, thereby achieving a clearer and more realistic effect;

[0099] (2) By matching the underlying wood grain print dataset with the 3D wood grain print dataset, a 3D wood grain layer can be obtained on the board surface that completely corresponds to the underlying wood grain layer, thereby effectively improving the accuracy of the alignment between the two. Furthermore, because this application processes different shape, color, and depth information separately, it simplifies the preparation process of the 3D wood grain layer and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0100] Figure 1 is a photograph of the underlying wood grain printed using prior art technology.

[0101] FIG. 2 is a first ink input value-first ink output value variation curve.

[0102] FIG. 3 is a curve showing a change in the first ink input value versus the second ink output value (black versus cyan).

[0103] FIG. 4 is a curve showing a change in the first ink input value versus the second ink output value (black versus magenta).

[0104] FIG5 is a curve showing a change in the first ink input value and the second ink output value (black-yellow).

[0105] FIG6 is a superimposed curve of the first ink input value and the second ink output value obtained by superimposing black ink, cyan ink, magenta ink, and yellow ink.

[0106] FIG7 is a photograph of the bottom wood grain printed by the method of the present application. DETAILED DESCRIPTION

[0107] The present invention will be further described below with reference to specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below generally represent only a portion of the present invention, rather than all of the embodiments. Therefore, all other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0108] The inventors of this application discovered in actual testing that, due to limitations in ink quality and color gamut, a single ink alone cannot achieve the desired color when printing two-dimensional wood grain. Therefore, it is often necessary to add other colors during the printing process, using multiple ink dots to overlay and print, to ensure the desired color is achieved. However, while existing color overprinting techniques can predict the final result within a certain range, they cannot always achieve optimal color output.

[0109] Therefore, in the prior art, in order to achieve more realistic and higher-definition two-dimensional wood grain printing, technicians in this field first select a first ink that is close to the color of the two-dimensional wood grain during the ink selection process, and then use some other second inks to assist, so as to obtain a state that is closer to the ideal wood grain color.

[0110] However, in actual operation, we found that the auxiliary color only ensures that the final two-dimensional wood grain has higher clarity and fidelity when it is within a small range. When the amount of auxiliary color used is small, the saturation of the final output color may decrease, resulting in unclearness. When the amount of auxiliary color used is too much, the final output color will be accompanied by a phenomenon of mixed colors (as shown in Figure 1, the wood grain in the figure has a problem of messy ink spots). Therefore, the key point of this embodiment is how to determine the ratio between the second ink and the first ink so that the final color obtained is clearer and more realistic.

[0111] To determine the usage ratio of the second ink to the first ink, the inventors first provide a step in this embodiment for obtaining a curve of first ink input versus first ink output from a first printing device. This step specifically includes simultaneously recording the expected concentration of the first ink input to the first printing device and the corresponding concentration of the first ink output from the first printing device. Using black ink as an example, the corresponding test results are shown in Table 1 below:

[0112] Table 1 Correspondence table of first ink input value and first ink output value

[0113] The data in Table 1 are integrated to obtain the first ink input value-first ink output value change curve shown in Figure 2, wherein the first ink input value-first ink output value change curve is fitted to obtain the first ink input value-first ink output value fitting equation. It should be noted that the fitting equation can change according to the change of the fitting method and is not unique. Therefore, the one listed below is only a preferred fitting equation.

[0114] One of the preferred fitting equations is as follows: y = a + b * x;

[0115] Where: y is the first ink output value, x is the first ink input value;

[0116] a=0.91956±0.16477

[0117] b=1.01505±0.00253.

[0118] After determining the first ink input value-first ink output value curve, cyan, magenta, and yellow inks are used as second inks to overlay the first ink. When the first ink is black and the blackness value of the color after overlaying the second colored ink with the black first ink reaches a maximum (the blackness value testing method can refer to the method described in standard GB / T7048-2012), the type of second ink and its output value are recorded, and the output value of the second ink is then determined.

[0119] Among them: the corresponding tables of the first ink input value-second ink output value (black-cyan, black-magenta, black-yellow) are shown in Table 2, Table 3, and Table 4 respectively.

[0120] Table 2 Correspondence table of first ink input value and second ink output value (black-cyan)

[0121] The data in Table 2 are integrated to obtain the first ink input value-second ink output value (black-cyan) change curve shown in Figure 3, wherein the first ink input value-second ink output value (black-cyan) change curve is fitted to obtain the first ink input value-second ink output value (black-cyan) fitting equation. It should be noted that the fitting equation can change according to the change of the fitting method and is not unique. Therefore, the one listed below is only a preferred fitting equation.

[0122] One fitting equation is as follows: y = A1*exp(-x / t1) + A2*exp(-x / t2) + A3*exp(-x / t3) + y0; where y is the second ink output value and x is the first ink input value;

[0123] y0=0.80406±0.30401

[0124] A1=0.00526±0.04909

[0125] t1=-9.24733±4.47594

[0126] A2=1.84081±171.05366

[0127] t2=-15.46834±63.15607

[0128] A3=-1.24152±171.2418

[0129] t3=-14.32169±68.29501.

[0130] Table 3 Correspondence table of first ink input value and second ink output value (black-magenta)

[0131] The data in Table 3 are integrated to obtain the first ink input value-second ink output value (black-magenta) change curve shown in Figure 4, wherein the first ink input value-second ink output value (black-magenta) change curve is fitted to obtain the first ink input value-second ink output value (black-magenta) fitting equation. It should be noted that the fitting equation can change according to the change of the fitting method and is not unique. Therefore, the one listed below is only a preferred fitting equation.

[0132] One of the fitting equations is as follows: equation y = A1*exp(x / t1) + y0;

[0133] Where: y is the second ink output value, x is the first ink input value;

[0134] y0=2.06391±0.24497

[0135] A1=0.11348±0.02295

[0136] t1=16.28326±0.59259.

[0137] Table 4 Correspondence table of first ink input value and second ink output value (black-yellow)

[0138] The data in Table 4 are integrated to obtain the first ink input value-second ink output value (black-yellow) change curve shown in Figure 5, wherein the first ink input value-second ink output value (black-yellow) change curve is fitted to obtain the first ink input value-second ink output value (black-yellow) fitting equation. It should be noted that the fitting equation can change according to the change of the fitting method and is not unique. Therefore, the one listed below is only a preferred fitting equation.

[0139] One of the fitting equations is as follows: y = y0 + A1*exp((x-x0) / t1) + A2*exp((x-x0) / t2);

[0140] y0=0.41038±0.02623

[0141] x0=76.54361±490453.27855

[0142] A1=6.27835E-8±0.022

[0143] t1=0.9682±224.88336

[0144] A2=-6.27657E-8

[0145] t2=0.96913±230.05037.

[0146] Figure 6 shows a superimposed curve of the first ink input value and the second ink output value, obtained by superimposing black ink as the first ink and cyan ink, magenta ink, and yellow ink as the second ink. In this case, the second ink output value on the same horizontal axis is the second ink output value that can assist the first ink in achieving the best display effect. Therefore, the present application compares the curves of different ink output values ​​to ultimately determine the inkjet volume of different inks. This means that we can accurately determine the inkjet volume of different inks based on the ink characteristic curves, thereby controlling the distribution of different inks on the surface of the board. Therefore, by matching the curves of different ink output values, the present application can accurately distribute the inkjet volume on the underlying wood grain surface to ensure the clarity and fineness of the wood grain. This personalized inkjet volume distribution can better adapt to the printing requirements of different wood grain shapes and textures, thereby achieving a clearer and more realistic effect. The underlying wood grain printed using the method of this application is shown in Figure 7. Comparing Figure 7 with Figure 1, it can be seen that the underlying wood grain printed using the method disclosed in this embodiment has higher clarity and does not exhibit any color variations.

[0147] After determining the inkjet amounts of the first and second inks that will produce the clearest and most realistic printed underlying wood grain, the present application further includes a step of establishing an underlying wood grain printing dataset. The underlying wood grain printing dataset includes an underlying wood grain shape dataset, the initial data of which is obtained by scanning a variety of natural wood species with a scanner.

[0148] For example, the shape image of wood grain of common natural wood includes, but is not limited to, closed, semi-closed, or fully open growth ring textures, semi-annular pore structures, striped structures, wavy structures, and burl textures. The obtained wood grain shape image is processed using image processing software. For example, the background image is corrected for color and / or brightness and / or contrast, and the wood grain shape image is processed by at least one of the following operations, such as geometric transformation, removal of unnecessary image elements, image skew, and image distortion. The processed wood grain information is then analyzed to extract and establish an underlying wood grain shape dataset, which is used to record the shape information of the wood grain on the wood surface.

[0149] Subsequently, the bottom wood grain shape data set and the inkjet amounts of the first ink and the second ink are simultaneously distributed to the first printing device, so as to output the bottom wood grain on the surface of the board.

[0150] The bottom wood grain printing background color data subset may include multiple background color printing point coordinate data (X, Y), each background color printing point coordinate data (X, Y) is marked with color information (black, cyan, magenta, yellow) that matches different colors of the wood grain pattern.

[0151] Specifically, the underlying wood grain shape data set includes multiple sets of two-dimensional plane wood grain printing coordinate data for printing wood grain. Each plane wood grain printing coordinate data is marked with color information (black, cyan, magenta, yellow). These color information constituting the wood grain can be distinguished from the color information constituting the background color, so that the shape of the underlying wood grain can be displayed on the background color. After determining the plane wood grain printing coordinate data, each underlying wood grain printing shape data subset can correspond to an underlying wood grain printing route.

[0152] The first printing device uses multiple sets of planar wood grain printing coordinate data for printing wood grain, as well as the color information corresponding to the planar wood grain printing coordinate data, recorded in the underlying wood grain shape data set, to print on the substrate surface according to the underlying wood grain printing path corresponding to each subset of the underlying wood grain printing shape data. This outputs colored ink used to form the wood grain shape on the substrate surface, thereby forming the wood grain shape. To ensure the clarity of the overall underlying wood grain after printing, the first printing device must maintain a printing resolution of greater than or equal to 100 DPI when printing the planar wood grain printing coordinate data used to form the wood grain shape.

[0153] The colored ink used in the first printing device is preferably a photocurable ink. After printing, the resulting underlying wood grain layer is photocured to maintain its stability and wear resistance. To ensure the photocurability of the colored ink, in this embodiment, the colored ink must include a photocurable resin, a photoinitiator for initiating the curing of the photocurable resin, and pigments for providing different colors.

[0154] Furthermore, since the board materials used in this embodiment can be wood-plastic board, stone-plastic board, wood board, metal board, or other types of board materials, and each type of board material has a different inherent color, after printing the underlying wood grain layer on different board surfaces, the inherent color of the board material will cause a certain degree of color shift in the underlying wood grain layer. Therefore, in some preferred embodiments of this application, the board material needs to undergo a certain surface modification treatment first.

[0155] The surface modification of the board includes the following steps:

[0156] The SPC board is first coated with a layer of curable primer (for example, the primer may contain: 90% light curing varnish HYS01-1, 5% photoinitiator 184, 0.5% photoinitiator TPO, 4.5% diluent hydroxyethyl acrylate), and 12g / m2 of the primer is applied to the SPC board while the SPC board is in contact with the coating roller. 2 The primer is applied to the surface of the SPC board with a 395nm and 8W / cm 2 The primer is cured by a UV lamp to form a primer layer.

[0157] The SPC sheet obtained in the previous step is passed through a roller coater. The surface of the roller coater is coated with a light-curable white paint (for example, the white paint contains: 50% light-curing epoxy HYS01-1, 30% titanium dioxide, 5% photoinitiator 184, 0.5% photoinitiator TPO, and 14.5% diluent hydroxyethyl acrylate). When the SPC sheet is in contact with the coating roller, 18g / m 2 The white paint is applied on the surface of the primer, and the 2 After curing with a UV lamp, a white paint layer is obtained.

[0158] The first printing device outputs on the surface of the white paint layer, thereby forming an underlying wood grain layer on the surface of the paint layer to cover up the influence of the color of the SPC board itself on the underlying wood grain.

[0159] After the base wood grain is formed on the substrate surface by printing using the first printing device, the method in this embodiment further includes a step of establishing a three-dimensional wood grain printing dataset, wherein the three-dimensional wood grain printing dataset includes a three-dimensional wood grain shape data subset corresponding to the base wood grain shape data subset and a three-dimensional wood grain printing depth data subset matching the three-dimensional wood grain shape data subset. The three-dimensional wood grain shape data subset includes multiple two-dimensional three-dimensional wood grain printing coordinate data for printing the wood grain, each three-dimensional wood grain shape data subset corresponding to a three-dimensional wood grain printing route, and the multiple three-dimensional wood grain printing routes respectively overlap with the multiple base wood grain printing routes on the two-dimensional plane. The three-dimensional wood grain printing depth data subset includes printing depth data for each three-dimensional wood grain printing coordinate data.

[0160] In order to form three-dimensional wood grain on the surface of the underlying wood grain that is compatible with the wood grain shape in the underlying wood grain, in this embodiment, a subset of the three-dimensional wood grain shape data and a subset of the three-dimensional wood grain printing depth data in the three-dimensional wood grain printing data set are respectively assigned to the second printing device, thereby forming three-dimensional wood grain during the printing process of the second printing device.

[0161] As described in the background art, there are various methods for forming three-dimensional wood grain, so the method of printing three-dimensional wood grain using the second printing device also needs to be explained separately.

[0162] The steps of a preferred embodiment of forming three-dimensional wood grain using the upward stacking method are as follows:

[0163] (1) Preparation of wood grain precursor liquid: In this embodiment, since the wood grain precursor liquid needs to be stacked upward to form three-dimensional wood grain, the wood grain precursor liquid used must include at least a curable resin and a photoinitiator (as an example, the wood grain precursor liquid used in the upward stacking method may include 40% polyurethane acrylate, 5% silica, 15% hydroxyethyl acrylate, 30% aluminum oxide, 5% photoinitiator 184, 0.5% photoinitiator TPO, and 4.5% diluent).

[0164] (2) The second printing device prints on the surface of the bottom wood grain layer according to the multiple two-dimensional three-dimensional wood grain printing coordinate data corresponding to the three-dimensional wood grain shape data subset and the three-dimensional wood grain printing route corresponding to each three-dimensional wood grain shape data subset, thereby outputting a wood grain precursor liquid on the bottom wood grain surface. The height of the wood grain precursor liquid can be controlled by the second printing device using the three-dimensional wood grain printing depth data subset, so that the wood grain precursor is finally formed in the process of continuously piling up the wood grain precursor liquid. In this embodiment, the three-dimensional wood grain printing routes corresponding to the multiple three-dimensional wood grain shape data subsets respectively overlap with the multiple bottom wood grain printing routes on the two-dimensional plane, thereby completing the alignment between the three-dimensional wood grain and the bottom wood grain.

[0165] (3) The wood grain precursor was sequentially subjected to 395nm and 8W / cm 2 UV lamp and 160w / cm 2 The Hg lamp irradiates the liquid wood grain precursor to transform into a solidified three-dimensional wood grain layer.

[0166] The steps of a preferred embodiment of forming three-dimensional wood grain using the downward indentation method are as follows:

[0167] (1) Preparation of wood grain precursor liquid: In this embodiment, since the wood grain precursor liquid needs to penetrate downward into the liquid resin layer to form three-dimensional wood grain, the wood grain precursor liquid used must at least include an inhibitor that hinders or delays the polymerization of the resin liquid layer (as an example, the wood grain precursor liquid used in the upward stacking method contains: 45.5% diacrylate monomer PEG600DA, 20.5% p-hydroxyanisole HQMME, 10% 2-tert-butylhydroquinone MTBHQ, and 24% diethylene glycol butyl ether).

[0168] (2) With the help of a coating tool, a curable liquid resin is applied on the bottom wood grain layer. The coating amount of the curable liquid resin can be 50 to 200 g / m 2 When the coating amount of the cured liquid resin is greater than 150g / m 2When the liquid resin layer is applied, the coating can be carried out in batches to form a liquid resin layer.

[0169] (3) The second printing device prints on the surface of the liquid resin layer according to the two-dimensional three-dimensional wood grain printing coordinate data corresponding to the three-dimensional wood grain shape data subset and the three-dimensional wood grain printing route corresponding to each three-dimensional wood grain shape data subset, thereby outputting the wood grain precursor liquid on the surface of the liquid resin layer. The depth of the wood grain precursor liquid can be controlled by the second printing device using the wood grain printing depth data subset, so that the wood grain precursor liquid and / or at least a portion of the liquid resin mixed with the wood grain precursor liquid and / or at least a portion of the liquid resin covered by the wood grain precursor liquid forms a wood grain precursor. In this embodiment, the three-dimensional wood grain printing routes corresponding to the multiple three-dimensional wood grain shape data subsets respectively overlap with the multiple bottom wood grain printing routes on the two-dimensional plane, thereby completing the alignment between the three-dimensional wood grain and the bottom wood grain.

[0170] (4) The liquid resin layer on the surface of the SPC sheet obtained in the previous step was sequentially subjected to 395nm and 8W / cm 2 UV lamp and 160w / cm 2 The SPC board is irradiated with an Hg lamp to achieve deep curing, and then the obtained SPC board is conveyed to a cleaning device including a steel brush, so that the wood grain precursor is brushed out by the steel brush, thereby forming a three-dimensional wood grain layer.

[0171] In some preferred embodiments, in order to improve the wear resistance and scratch resistance of the bottom wood grain layer and to make the three-dimensional wood grain layer have better stereoscopic effect and visual effect, a pre-treatment step is performed after obtaining the bottom wood grain.

[0172] The pre-processing step comprises:

[0173] The step of covering at least a portion of the surface of the bottom wood grain square with a curable liquid resin and curing it. The amount of the resin liquid applied by roller is about 45g / m 2 The photocurable resin liquid (as an example, the resin liquid contains: polyurethane acrylate 40%, 5% silicon dioxide, 15% hydroxyethyl acrylate, 30% aluminum oxide, 5% photoinitiator 184, 0.5% photoinitiator TPO, 4.5% diluent) 90% Dow Corning 65Additive, 5% photoinitiator 184, 0.5% photoinitiator TPO, 4.5% diluent hydroxyethyl acrylate) was sequentially subjected to 395nm and 8W / cm 2 UV lamp and 160w / cm 2 After being irradiated and cured by an Hg lamp, a three-dimensional wood grain base layer is formed, and then a three-dimensional wood grain layer is formed on top of the three-dimensional wood grain base layer.

[0174] In some preferred embodiments, in order to improve the touch feel of the board and adjust the optical properties, after preparing the three-dimensional wood grain layer, it is necessary to continue to apply at least one layer of topcoat on the surface of the three-dimensional wood grain layer and solidify it to obtain the topcoat layer.

[0175] Taking the coating of double-layer topcoat as an example, in some preferred embodiments: first, the board is passed through a roller coater, thereby coating the surface of the three-dimensional wood grain layer with 12g / m 2 The first topcoat was then subjected to a 395nm and 8W / cm 2 The first topcoat layer is obtained by irradiating with an ultraviolet lamp to cure the first topcoat layer;

[0176] Then, the plate 10 obtained in the previous step was again subjected to a roller coater and a 395 nm and 8 W / cm 2 UV lamp, thereby coating 12g / m on the surface of the first topcoat layer 2 The second topcoat is applied and cured to obtain a second topcoat layer.

[0177] In summary, this application uses a "curve matching" method to accurately determine the inkjet volume of different inks based on the ink's characteristic curve, thereby controlling the distribution of different inks on the board surface. By matching the curves of different ink output values, the ink jet volume can be accurately distributed across the underlying wood grain surface to ensure the clarity and fineness of the wood grain. This personalized ink jet volume distribution can better adapt to the printing needs of different wood grain shapes and textures, achieving a clearer and more realistic effect.

[0178] In addition, the present application can also obtain three-dimensional wood grain similar to natural wood board on the surface of artificial or non-wood board, and by digitizing the wood grain information, it can make the bottom wood grain layer and the three-dimensional wood grain located above the bottom wood grain layer strictly correspond to each other during the printing process, thereby overcoming the problem of difficulty in "matching patterns" in the existing technology.

[0179] At the same time, based on the above principles, the method in the present application also has the advantage of high flexibility. Compared with the existing technology, the three-dimensional wood grain in the present application does not require three-dimensional modeling of a single underlying wood grain layer. It only needs to analyze the wood grain shape contained in the underlying wood grain layer, and obtain it by retrieving it from the three-dimensional wood grain printing shape data subset of the three-dimensional wood grain printing data set, and match the shape data recorded in the three-dimensional wood grain printing shape data subset with the depth data recorded in the three-dimensional wood grain printing depth data subset, so as to create a three-dimensional wood grain that is closer to natural wood grain, thereby effectively simplifying the construction process of the three-dimensional wood grain, so that customized production of products can be carried out according to customer needs, expanding the richness of the company's product line, effectively reducing production costs and improving production efficiency.

[0180] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A method for printing a three-dimensional plate with a clear wood grain effect, characterized in that: It includes at least the following steps: - obtaining a first ink input value-first ink output value variation curve of a first printing device; - obtaining at least one second ink output value of the first printing device that matches the first ink input value-first ink output value variation curve, thereby obtaining at least one first ink input value-second ink output value variation curve; - determining the ejection amounts of the first ink and the second ink based on the first ink input value-first ink output value variation curve and the first ink input value-second ink output value variation curve; - allocating the inkjet amounts of the first ink and the second ink determined based on the first ink input value-first ink output value variation curve and the first ink input value-second ink output value variation curve to the first printing device, thereby outputting the bottom layer wood grain on the surface of the board; -A three-dimensional wood grain that matches the shape of the underlying wood grain is printed on the surface of the underlying wood grain using a second printing device to obtain a three-dimensional board with a clear wood grain effect.

2. The method for printing a three-dimensional plate with a clear wood grain effect according to claim 1, characterized in that: When the first ink is achromatic ink, the output value of the second ink is the second ink output value corresponding to the maximum blackness value after the first ink and the second ink are superimposed; When the first ink is colored ink, the output value of the second ink is the second ink output value corresponding to the maximum saturation value after the first ink and the second ink are superimposed.

3. The method for printing a three-dimensional plate with a clear wood grain effect according to claim 2, characterized in that: The achromatic ink is black ink; The colored ink is a combination of at least one or more of cyan ink, magenta ink, and yellow ink.

4. The method for printing a three-dimensional plate with a clear wood grain effect according to claim 1, characterized in that: The following steps are also included: - The step of establishing a bottom wood grain printing dataset and a three-dimensional wood grain printing dataset; wherein, The bottom wood grain printing dataset includes a bottom wood grain shape dataset; The three-dimensional wood grain printing data set includes a three-dimensional wood grain shape data subset corresponding to the bottom wood grain shape data set and a three-dimensional wood grain printing depth data subset matching the three-dimensional wood grain shape data subset; - Simultaneously allocating the bottom wood grain shape dataset and the inkjet amounts of the first ink and the second ink to the first printing device, thereby outputting the bottom wood grain on the surface of the board; - Assigning the three-dimensional wood grain printing data set to the second printing device, so that printing is performed on the bottom wood grain surface by the second printing device to obtain a three-dimensional wood grain that matches the shape of the bottom wood grain, and the height or depth of the three-dimensional wood grain corresponds to the three-dimensional wood grain printing depth data subset.

5. The method for printing a three-dimensional plate with a clear wood grain effect according to claim 4, characterized in that: The underlying wood grain shape data set includes multiple sets of plane wood grain printing coordinate data for printing wood grain shapes, each plane wood grain printing coordinate data corresponds to the underlying wood grain color data in the underlying wood grain color data set, and the first printing device prints based on the plane wood grain printing coordinate data and the underlying wood grain color data, and each plane wood grain printing coordinate data corresponds to a underlying wood grain printing route.

6. The method for printing a three-dimensional plate with a clear wood grain effect according to claim 5, characterized in that: The 3D wood grain shape data subset includes multiple two-dimensional 3D wood grain printing coordinate data for printing wood grains. Each 3D wood grain shape data subset corresponds to a 3D wood grain printing route. The multiple 3D wood grain printing routes respectively overlap with the multiple bottom wood grain printing routes on the two-dimensional plane.

7. The method for printing a three-dimensional plate with a clear wood grain effect according to claim 6, characterized in that: The three-dimensional wood grain printing depth data subset includes printing depth data of each three-dimensional wood grain printing coordinate data.

8. The method for printing a three-dimensional plate with a clear wood grain effect according to claim 4, characterized in that: The three-dimensional wood grain printing step includes the following steps: - outputting a wood grain precursor liquid using the three-dimensional wood grain printing data set through a second printing device, thereby depositing a wood grain precursor that matches the shape of the underlying wood grain on the surface of the underlying wood grain; - Applying energy to the wood grain precursor so that the wood grain precursor is solidified to obtain three-dimensional wood grain.

9. The method for printing a three-dimensional plate with a clear wood grain effect according to claim 8, characterized in that: The wood grain precursor liquid at least includes a photocatalytic resin and a photoinitiator for initiating polymerization of the photocatalytic resin.

10. The method for printing a three-dimensional plate with a clear wood grain effect according to claim 8, characterized in that: The wood grain precursor liquid at least includes a thermosetting resin and a curing agent for curing the thermosetting resin.

11. The method for printing a three-dimensional plate material with a clear wood grain effect according to claim 8, 9 or 10, characterized in that: The bottom wood grain surface is also evenly coated with a three-dimensional base material layer by means of a coating tool, and the wood grain precursor is deposited on the surface of the three-dimensional base material layer.

12. The method for printing a three-dimensional plate with a clear wood grain effect according to claim 4, characterized in that: The three-dimensional wood grain printing step includes the following steps: - applying a curable liquid resin on the bottom wood grain layer by means of a coating tool, thereby forming a liquid resin layer; - outputting a wood grain precursor liquid on a surface of the liquid resin layer using the three-dimensional wood grain printing dataset via a second printing device, so that the wood grain precursor liquid and / or at least a portion of the liquid resin mixed with the wood grain precursor liquid and / or at least a portion of the liquid resin covered by the wood grain precursor liquid forms a wood grain precursor; - applying energy to the liquid resin layer to cure the liquid resin layer, so that the liquid resin except the wood grain precursor is cured; - A step of removing the wood grain precursor, thereby obtaining three-dimensional wood grain.

13. The method for printing a three-dimensional plate with a clear wood grain effect according to claim 12, characterized in that: The three-dimensional wood grain printing step further includes a pre-processing step, which includes: The step of covering at least a portion of the surface above the bottom wood grain layer with a curable liquid resin and curing at least a portion of the curable liquid resin on the surface of the bottom wood grain layer to form a three-dimensional wood grain bottom layer.

14. The method for printing a three-dimensional plate with a clear wood grain effect according to claim 12 or 13, characterized in that: The wood grain precursor liquid at least contains a polymerization inhibitor for preventing or delaying polymerization of the curable liquid resin.

15. The method for printing a three-dimensional plate material with a clear wood grain effect according to claim 1, 4, 8 or 12, characterized in that: After the three-dimensional wood grain is prepared, the method further includes covering at least a portion of the surface of the three-dimensional wood grain layer with a topcoat and curing the topcoat layer.

16. Three-dimensional plate, characterized in that: It is prepared by the method according to any one of claims 1 to 15.

17. Use of the three-dimensional plate according to claim 16 in flooring, decorative wall panels or ceiling panels.

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