Quartz stone plate and surface pattern forming method and device thereof

Abstract

The invention discloses a quartzite plate and a surface pattern forming method and equipment thereof. The surface pattern forming method comprises the following steps: providing a cured and polished quartzite plate; the surface of the to-be-treated part of the quartz stone plate is pretreated; printing a predetermined pattern on the pretreated surface part by an ink-jet printer; curing the printed pattern; wherein the pretreatment is to treat the surface of the to-be-treated part by adopting a plasma surface treatment machine. According to the scheme, a simple process is adopted, the processing time can be saved on the premise that the pattern forming effect is ensured, and the defects in the prior art are overcome.

Description

Technical Field

[0001] This invention relates to the field of slab processing technology, and in particular to quartz slabs and methods and equipment for forming surface patterns thereon. Background Technology

[0002] Quartz stone slabs are artificial boards produced by mixing inorganic solid particles with resin adhesive, feeding the mixture into a mold or similar material, and then pressing, curing, and polishing them. They are often used for tabletops.

[0003] To enhance the decorative richness of the slab surface, such as mimicking the texture of natural stone, patterns are mainly formed on the slab surface through the following two methods.

[0004] One method involves mixing a textured dye (a different material from the substrate) into the substrate during the fabric application process. After pressing and curing, the dye exposed on the surface of the slab naturally forms different patterns that resemble the texture of natural stone. The disadvantages of this method are the complexity of the fabric application process, leading to lower slab production efficiency. The presence of dye also increases production costs, as a significant portion of the dye is embedded within the substrate and does not participate in texture formation.

[0005] Another approach involves directly creating textures on the surface of the pre-formed board after pressing, curing, and polishing. This can be done through inkjet printing or transfer paper, forming the pattern directly on the board surface, followed by curing. The advantage of this technology is that it eliminates the need for a complex fabric application process. However, printing or transferring the pattern is a complex and inefficient process, adding an extra step. Furthermore, since the surface of a pre-formed board is generally very smooth and lacks good ink absorption, it is difficult for patterns formed on a cured board surface, whether through inkjet printing or transfer, to adhere firmly. Additionally, the printed or transferred pattern may become blurry or distorted before curing, affecting the overall pattern formation.

[0006] Chinese invention patent CN112092527A, entitled "A Method for Forming Patterns on a Substrate Surface," describes a method for roughening the surface of artificial stone where patterns are desired (while partially masking areas where patterns are not desired) using sandblasting or acid etching. UV inkjet printing is then applied to the roughened areas. The bonding strength between UV ink and the material is directly proportional to the surface roughness. A rough surface increases the contact area, allowing the material and UV ink to penetrate each other, achieving a bonding effect and increasing the adhesion strength between the UV ink and the substrate. However, the surface roughening process is time-consuming and prone to errors due to its complexity.

[0007] Chinese invention patent CN111393184A, entitled "A Method for Preparing Textures of Artificial Stone Slabs," describes a method that involves first printing a source image onto a drawing of the corresponding size, then placing the printed drawing face-up onto one surface of the artificial stone slab. The drawing and the artificial stone slab are then clamped together using the upper and lower layers of a heated ink-absorbing machine. Heating causes the ink from the plastic image to penetrate the surface of the artificial stone slab, which is then cooled to room temperature. The drawbacks of this method are that the printing process and the heating step in the transfer process are time-consuming, complex, and prone to errors.

[0008] Italian patent IT102021000003353B1, entitled "Method and System for Producing Mineral Particle Boards Bonded with Resin," describes a method that, on a cured finished sheet, provides at least one stage to increase the inherent porosity of the finished sheet, which facilitates ink penetration into the finished sheet before digital printing of ink decoration on the surface of the finished sheet according to a predetermined design. Specifically, the stage of increasing inherent porosity is carried out by heating at 30-180°C. Furthermore, an ink fixer can be applied to the surface of the sheet after heating and before digital printing to promote ink adhesion to the finished sheet surface; alternatively, the ink fixer can be applied before heating. The drawback is that both the heating process and the application of the ink fixer are time-consuming, complex, and prone to errors.

[0009] Italian patents IT102022000000026B1, "Method for producing a slab with decorative and / or color effects from stone or stone aggregate material, the slab obtained therefrom, and an intermediate for processing the slab," and IT102023000000510B1, "Method and apparatus for manufacturing a slab of stone or aggregate stone type material with textured and colored surface effects, and the slab obtained therefrom," both involve applying a primer composed of an organic compound solution or dispersion (which promotes the adhesion of the disperse ink) to a hardened slab blank. The disperse ink is then applied to a film formed by the dried primer. The disperse ink is dried at a high temperature (85-100°C), cooled, and excess ink is removed. Finally, a functional compound of silazane solution is applied to form a protective layer that protects the colored effects created by the disperse ink. Its drawbacks are that it requires applying a primer, a process of heating and cooling, removal of excess ink, and finally the formation of a protective layer, which is time-consuming and the process is complex and prone to errors.

[0010] Therefore, there is an urgent need for a method for forming surface patterns on quartz stone slabs to simplify the process and form stable surface patterns, thereby saving processing time. Summary of the Invention

[0011] The purpose of this invention is to propose a method and equipment for forming patterns on quartz stone slabs and their surfaces, which adopts a simple process and saves processing time while ensuring the pattern forming effect.

[0012] To achieve this objective, the present invention adopts the following technical solution: A method for forming a surface pattern on a quartz stone slab includes the following steps: We offer pre-cured and polished quartz stone slabs; The surface of the portion of the quartz stone slab to be treated is pretreated; A predetermined pattern is printed on a pre-treated surface area by an inkjet printer; The printed pattern is then solidified; The pretreatment involves using a plasma surface treatment machine to treat the surface of the part to be treated.

[0013] Preferably, after the printed pattern has been cured, excess uncured ink on the surface of the quartz slab is removed.

[0014] Preferably, before printing, the distance between the printhead of the inkjet printer and the quartz stone slab is adjusted to a preset printing distance, and the preset printing distance is 2 to 15 mm.

[0015] Preferably, during the pretreatment process, the plasma surface treatment machine treats all surfaces of the quartz stone slab.

[0016] Preferably, the ink raw material for printing includes organic dyes, and the organic dyes include color particles and solvents, wherein the particle size of the color particles is 60-200 nm.

[0017] Preferably, the input gas for the plasma surface treatment machine is clean air.

[0018] Preferably, during the curing process of the printed pattern, the temperature difference between different locations of the quartz stone slab is less than 20°C, and the curing temperature is 120-150°C.

[0019] A surface pattern forming device for quartz stone slabs, used to implement the above-mentioned surface pattern forming method for quartz stone slabs, includes a conveying device, two gantry frames, an inkjet printer, and a plasma surface treatment machine; Two gantry frames are spaced apart and erected above the conveying device, and the conveying device is capable of longitudinal movement relative to the two gantry frames; The inkjet printer is mounted on any gantry, and the inkjet printer can move laterally relative to the gantry, and the direction of movement of the inkjet printer is perpendicular to the conveying direction of the conveying device. The plasma surface treatment machine is mounted on another gantry, and the plasma surface treatment machine can move laterally relative to the gantry, and the direction of movement of the plasma surface treatment machine is perpendicular to the conveying direction of the conveying device. The inkjet printer and the plasma surface treatment machine are arranged sequentially along the conveying direction of the conveying device; The conveying device is used to convey quartz stone slabs; The plasma surface treatment machine is used to treat the surface of the quartz stone slab to be treated; The inkjet printer is used to print a predetermined pattern on a pre-treated surface portion.

[0020] A quartz stone slab, prepared using the above-mentioned method for forming a surface pattern of quartz stone slab, wherein the ink penetration depth in the cured pattern-forming area is ≤0.3mm.

[0021] Preferably, after curing, the reflectivity of the pattern-forming area is 25-90%, and the Mohs hardness is 3-4.

[0022] The technical solution provided by this invention may include the following beneficial effects: The present invention proposes a method and equipment for forming surface patterns on quartz stone slabs. It adopts a simple process and can save processing time while ensuring the pattern forming effect, thus overcoming the shortcomings of the prior art. Attached Figure Description

[0023] Figure 1 This is a schematic diagram illustrating the printing effect of an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the printing effect of Comparative Example 1 of the present invention.

[0025] Figure 3 This is a schematic diagram of the printing effect of Comparative Example 2 of the present invention. Detailed Implementation

[0026] A method for forming a surface pattern on a quartz stone slab includes the following steps: We offer pre-cured and polished quartz stone slabs; The surface of the portion of the quartz stone slab to be treated is pretreated; A predetermined pattern is printed on a pre-treated surface area by an inkjet printer; The printed pattern is then solidified; The pretreatment involves using a plasma surface treatment machine to treat the surface of the part to be treated.

[0027] To save processing time while ensuring the desired pattern formation effect, this technical solution proposes a method of plasma treatment on the surface of the quartz stone slab to be treated. This plasma treatment improves the wettability of the slab surface through the following two mechanisms: 1. Introduction of polar functional groups: The active particles in the plasma react chemically with the surface of the board to introduce oxygen- or nitrogen-containing polar groups (such as C—O, C=O, C=O—O, etc.), which enhance the polarity of the board surface and thus improve wettability. 2. Surface etching and roughening: The physical bombardment of high-energy particles creates rough structures such as micro-pits and micro-grooves on the surface of the board, which increases the mechanical interlocking between the board surface and the printed pattern, further improving wettability and adhesion.

[0028] In other words, this solution uses a simple process that can save processing time while ensuring the desired pattern formation effect.

[0029] To further explain, after the printed pattern has been cured, excess uncured ink on the surface of the quartz slab is removed.

[0030] In one specific embodiment, a protective layer may be applied to the surface of the quartz slab after the printed pattern has been cured. Specifically, the protective layer may be an organic polymer coating (such as polyurethane resin, epoxy resin, silicone resin, etc.), a polymer film (such as PVC film, PET film, etc.), or an inorganic coating (such as a nano-ceramic coating, metal oxide plating, etc.), and is not limited thereto.

[0031] To further explain, before printing, the distance between the inkjet printer nozzle and the quartz stone slab is adjusted to a preset printing distance, and the preset printing distance is 2 to 15 mm.

[0032] In the actual production process of quartz stone slabs, it is difficult to achieve a completely flat surface; a warp of 2–15 mm is common. However, inkjet printer printheads can generally only move along a single horizontal plane and cannot adjust their height in real time to follow the warp of the slab. This solution optimizes the distance between the inkjet printer printhead and the quartz stone slab to be 2–15 mm, with closer distances resulting in higher printing accuracy. If the distance is too low, the warp of the quartz stone slab may scratch the printhead; if the distance is too high, the quartz stone slab will be unsuitable for printing.

[0033] To further explain, during the pretreatment process, the plasma surface treatment machine treats all surfaces of the quartz stone slab.

[0034] While treating only a portion of the surface requiring inkjet printing might save plasma and be faster, in practice, precisely positioning the plasma surface treatment machine to that specific area requires detailed programming of the machine's drive mechanism and precise sensor configuration, significantly increasing both the machine's operational status and hardware costs. Therefore, treating the entire surface of quartz stone slabs with a plasma surface treatment machine is more cost-effective in terms of programming, control, and drive hardware.

[0035] To further explain, the ink raw material for printing includes organic dyes, and the organic dyes include color particles and solvents, and the particle size of the color particles is 60-200 nm.

[0036] Furthermore, this solution uses printing ink made from organic dyes because it has the property of sublimating in the temperature range of 120–200°C, and the sublimated molecules are small enough to penetrate into the quartz stone slab. If pigment ink made from solid inorganic pigments is used, even if the above temperature range is reached, the physical properties of the pigments will prevent the particles from penetrating the surface of the slab, and the ink will easily wipe off after drying, making it difficult to ensure the image formation effect.

[0037] It should be noted that the organic dyes used in this scheme can be detected by any of the following test methods: (1) When organic dyes are heated to above 130°C, there are obvious diffusion and sublimation phenomena.

[0038] (2) Heat the organic dye to above 130°C so that the vapor of the organic dye adheres to the surface of the quartz stone slab; after 1 hour, there will be obvious color marks left on the surface of the quartz stone slab, which cannot be wiped off with paper or hands.

[0039] It should be further explained that even when the inorganic ink is heated to above 130°C and its vapor is applied to the surface of the quartz stone slab, no marks will be left on the surface of the quartz stone slab after 1 hour; the marks can be easily wiped off.

[0040] (3) When organic dyes are placed in a container and heated with a lighter, they will undergo obvious sublimation. If paper is placed on the vapor of organic dyes, it will be stained.

[0041] To further clarify, the input gas for the plasma surface treatment machine is clean air.

[0042] In one specific embodiment, the clean gas introduced during the plasma surface treatment is at a pressure of 0.4 MPa, a flow rate of 120 L / min, and an ionization driving power of 800 W. The effective treatment diameter of a single plasma particle in the plasma surface treatment is 80 mm. Specifically, in the plasma surface treatment process of this scheme, clean compressed gas is introduced into the plasma generation chamber at a pressure of 0.4 MPa and a flow rate of 120 L / min. The gas is then driven by an 800 W driving power to ionize it into plasma. Finally, the ionized plasma is ejected in a stable form under the pressure of the gas, forming an effective treatment area with a diameter of 80 mm, thus treating the surface of the quartz stone slab to be treated.

[0043] To further clarify, during the curing process of the printed pattern, the temperature difference between different locations on the quartz stone slab is less than 20°C.

[0044] Due to the inherent properties of printing ink, its final color will change depending on the highest temperature reached during curing. To ensure the printing effect, this solution preferably maintains a temperature difference of less than 20℃ between different locations on the quartz stone slab during the curing process.

[0045] To further explain, the curing temperature for curing the printed pattern is 120–150°C.

[0046] The preferred curing temperature in this design is 120–150°C, which can be adjusted according to different quartz printing substrates and inks. If the curing temperature is too high, the substrate may deform and discolor; if the curing temperature is too low, the ink may not sublimate sufficiently to color the substrate.

[0047] In one specific embodiment, the curing process can use a curing oven commonly used in the art. The curing principle is to generate heat by an electric heating wire or a gas burner, heat the air inside the oven, and finally transfer the heat to the board.

[0048] A surface pattern forming device for quartz stone slabs, used to implement the above-mentioned surface pattern forming method for quartz stone slabs, includes a conveying device, two gantry frames, an inkjet printer, and a plasma surface treatment machine; Two gantry frames are spaced apart and erected above the conveying device, and the conveying device is capable of longitudinal movement relative to the two gantry frames; The inkjet printer is mounted on any gantry, and the inkjet printer can move laterally relative to the gantry, and the direction of movement of the inkjet printer is perpendicular to the conveying direction of the conveying device. The plasma surface treatment machine is mounted on another gantry, and the plasma surface treatment machine can move laterally relative to the gantry, and the direction of movement of the plasma surface treatment machine is perpendicular to the conveying direction of the conveying device. The inkjet printer and the plasma surface treatment machine are arranged sequentially along the conveying direction of the conveying device; The conveying device is used to convey quartz stone slabs; The plasma surface treatment machine is used to treat the surface of the quartz stone slab to be treated; The inkjet printer is used to print a predetermined pattern on a pre-treated surface portion.

[0049] In one specific embodiment, the conveying device may be a belt conveyor, a roller conveyor, etc., which is not limited here.

[0050] A quartz stone slab, prepared using the above-mentioned method for forming a surface pattern of quartz stone slab, wherein the ink penetration depth in the cured pattern-forming area is ≤0.3mm.

[0051] To further explain, after curing, the reflectivity of the pattern-forming area is 25-90%, and the Mohs hardness is 3-4.

[0052] This design preferably uses a reflectance of 25% to 90% for the pattern formation area. If the reflectance is too low, the printed drawing will be difficult to display, failing to achieve its decorative purpose. It should be noted that the reflectance in this design refers to the proportion of reflected light to incident light, which can be measured using conventional reflectance measuring instruments.

[0053] In addition, the Mohs hardness of this solution can be tested using the following methods: Place the quartz slab sample stably on a hard support, with the veneer facing upwards. Use standard minerals of varying Mohs values, from lowest to highest, to scratch the sample surface. Apply even, vertical pressure with a fresh cutting edge of the mineral to scratch the sample surface, ensuring the pressure is moderate. The cutting edge of the standard mineral should not break due to excessive force, resulting in double or multiple scratch marks. The lowest hardness value that just produces a noticeable scratch is taken as the test result. The lowest value among all test values ​​for the sample is the final test result.

[0054] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0055] Example We offer pre-cured and polished quartz stone slabs; The entire surface of the quartz stone slab is completely and uniformly treated using a plasma surface treatment machine. A predetermined pattern is printed on the plasma-treated surface using an inkjet printer with ink containing organic dyes. The printed pattern is solidified, and the printed effect is shown in the schematic diagram below. Figure 1 As shown.

[0056] Comparative Example 1 Provide the same quartz stone slabs as in the embodiment; A predetermined pattern is printed on the entire surface of a quartz slab using an inkjet printer with an ink containing organic dyes. The printed pattern is solidified, and the printed effect is shown in the schematic diagram below. Figure 2 As shown.

[0057] Comparative Example 2 Provide the same quartz stone slabs as in the embodiment; The quartz stone slab is placed in a heating furnace at 170°C for heat treatment, and the surface of the quartz stone slab is heated to 70°C. A predetermined pattern is printed by an inkjet printer on a heat-treated surface using ink containing organic dyes. The printed pattern is solidified, and the printed effect is shown in the schematic diagram below. Figure 3 As shown.

[0058] like Figure 1-3 The printed effect diagram includes multiple color blocks, each with a number below it. This number represents the total ink volume (relative value) of the printed color block above it; 0 represents no ink, and 400 represents the maximum ink volume the printer can print in a single pass. It can be seen that Comparative Example 1 already exhibits severe ink droplet aggregation at 256 color blocks, which is detrimental to the final printing effect. However, the 256 color blocks in the embodiment still show no obvious ink droplet aggregation. Therefore, it can be concluded that the plasma-treated board will have a better printing effect than the untreated one, and can maintain a similar effect to the heat-treated (i.e., Comparative Example 2) at ink volumes below 280.

[0059] It should be noted that in the embodiment, when the plasma surface treatment machine is used to treat the entire surface of the quartz stone slab, the processing time is only 4 minutes. In contrast, in Comparative Example 2, the quartz stone slab needs to be heated for at least 10 minutes to reach a temperature similar to that of the embodiment, and the uniformity is not as good. Although the heating method can accelerate the heating rate of the slab by increasing the furnace temperature, excessively high furnace temperatures will also cause the slab temperature to rise too quickly, making precise temperature control impossible and unsuitable for actual production.

[0060] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. A method for forming a surface pattern on a quartz stone slab, comprising the following steps: We offer pre-cured and polished quartz stone slabs; The surface of the portion of the quartz stone slab to be treated is pretreated; A predetermined pattern is printed on a pre-treated surface area by an inkjet printer; The printed pattern is then solidified; The characteristic feature is that the pretreatment is performed by using a plasma surface treatment machine to treat the surface of the part to be treated.

2. The method for forming a surface pattern on a quartz stone slab according to claim 1, characterized in that, After the printed pattern has cured, remove any excess uncured ink from the surface of the quartz slab.

3. The method for forming a surface pattern on a quartz stone slab according to claim 1, characterized in that, Before printing, the distance between the inkjet printer nozzle and the quartz stone slab is adjusted to a preset printing distance, which is 2 to 15 mm.

4. The method for forming a surface pattern on a quartz stone slab according to claim 1, characterized in that, During the pretreatment process, the plasma surface treatment machine treats all surfaces of the quartz stone slab.

5. The method for forming a surface pattern on a quartz stone slab according to claim 1, characterized in that, The ink raw material for printing includes organic dyes, and the organic dyes include color particles and solvents, wherein the particle size of the color particles is 60-200 nm.

6. The method for forming a surface pattern on a quartz stone slab according to claim 1, characterized in that, The input gas for the plasma surface treatment machine is clean air.

7. The method for forming a surface pattern on a quartz stone slab according to claim 1, characterized in that, During the curing process of the printed pattern, the temperature difference between different locations of the quartz stone slab is less than 20°C, and the curing temperature is 120-150°C.

8. A surface pattern forming device for quartz stone slabs, characterized in that, The method for forming a surface pattern of quartz slabs according to any one of claims 1 to 7 includes a conveying device, two gantry frames, an inkjet printer, and a plasma surface treatment machine. Two gantry frames are spaced apart and erected above the conveying device, and the conveying device is capable of longitudinal movement relative to the two gantry frames; The inkjet printer is mounted on any gantry, and the inkjet printer can move laterally relative to the gantry, and the direction of movement of the inkjet printer is perpendicular to the conveying direction of the conveying device. The plasma surface treatment machine is mounted on another gantry, and the plasma surface treatment machine can move laterally relative to the gantry, and the direction of movement of the plasma surface treatment machine is perpendicular to the conveying direction of the conveying device. The inkjet printer and the plasma surface treatment machine are arranged sequentially along the conveying direction of the conveying device; The conveying device is used to convey quartz stone slabs; The plasma surface treatment machine is used to treat the surface of the quartz stone slab to be treated; The inkjet printer is used to print a predetermined pattern on a pre-treated surface portion.

9. A quartz stone slab, characterized in that, The quartz stone slab is prepared using the surface pattern forming method according to any one of claims 1 to 7, and the ink penetration depth of the cured pattern forming area is ≤0.3mm.

10. A quartz stone slab according to claim 9, characterized in that, After curing, the reflectivity of the pattern-forming area is 25-90%, and the Mohs hardness is 3-4.

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