Digital mold positioning dry granular ceramic tile with reduced number of blisters and pinholes and method for making the same

Abstract

The application discloses digital mold positioning dry particle ceramic tiles with reduced pimple and pinhole and a preparation method thereof, and the method comprises the following steps: A, a blank is formed by rolling and molding, and a body is obtained after first drying; B, mold ink and digital face glaze are printed on the surface of the body in sequence, and a digital mold layer is obtained after second drying; C, oily protective glaze ink is printed on the surface of the digital mold layer to obtain a moisture isolation layer; D, positioning glue and positioning dry particles are printed on the surface of the moisture isolation layer in sequence, and a positioning dry particle layer is obtained after third drying; E, protective glaze is sprayed on the surface of the positioning dry particle layer, and digital mold positioning dry particle ceramic tiles are obtained after fourth drying, firing and polishing in sequence. The scheme can effectively solve the problem of difficult exhaust caused by large thickness of the positioning dry particle layer and large number of dry particles, and improve the pimple and pinhole defects on the surface of the ceramic tiles, so as to overcome the shortcomings in the prior art.

Description

Technical Field

[0001] This invention relates to the field of building ceramics technology, and in particular to a digital mold positioning dry granule ceramic tile that reduces prickly heat and pinholes, and its preparation method. Background Technology

[0002] With the increasing demand for aesthetically pleasing and personalized ceramic tiles in the building decoration industry, digital mold-positioned dry-granule ceramic tiles have become one of the mainstream products in the high-end decoration field due to their unique surface texture and decorative effect. The positioning dry-granule layer is one of the core structures that determines the decorative effect of digital mold-positioned dry-granule ceramic tiles. To ensure a strong decorative texture with a raised surface, existing technologies typically adopt the design approach of increasing the thickness of the dry-granule layer and improving the density of the dry-granule laying, so as to ensure that the positioning dry-granule layer forms a decorative layer with a strong three-dimensional effect.

[0003] However, the above design concept has inherent flaws. The positioning dry granule layer with a large thickness and a large number of dry granules will make it difficult to exhaust air during the sintering process of the tile, which will lead to serious appearance defects such as prickly heat and pinholes on the surface of the tile. This has become the core technical pain point that restricts the improvement of the quality and the expansion of production capacity of this type of tile.

[0004] Currently, although the industry has tried to improve exhaust performance by optimizing sintering curves and reducing organic additives in the positioning dry granule layer, these solutions either reduce production efficiency or fail to fundamentally solve the problem of exhaust channel blockage caused by thick dry granule layers and high dry granule density. Defects such as blemishes and pinholes are still difficult to completely eliminate.

[0005] In summary, the difficulty in venting existing digital mold-positioned dry-granule ceramic tiles due to the large thickness and quantity of the positioning dry-granule layer has become a key bottleneck restricting product quality and production efficiency. Solving the venting problem and eliminating surface blemishes and pinholes while ensuring the decorative effect of the positioning dry-granule layer has become a core technological need that the ceramic industry urgently needs to overcome. Summary of the Invention

[0006] The purpose of this invention is to propose a digital mold positioning dry granule ceramic tile and its preparation method to reduce prickly heat and pinholes. It can effectively solve the problem of difficult air release caused by the large thickness of the positioning dry granule layer and the large number of dry granules, improve the defects of prickly heat and pinholes on the surface of the ceramic tile, and overcome the shortcomings of the prior art.

[0007] To achieve this objective, the present invention adopts the following technical solution: A method for preparing digitally molded, dry-granule ceramic tiles that reduce prickly heat and pinholes includes the following steps: A. The billet is rolled into shape and dried for the first time to obtain the billet body; B. Print mold ink and spray digital glaze sequentially on the surface of the blank, and obtain the digital mold layer after a second drying. C. Print an oil-based protective glaze ink on the surface of the digital mold layer to obtain a moisture isolation layer; D. Sequentially print positioning adhesive and lay positioning dry granules on the surface of the moisture isolation layer, and obtain the positioning dry granule layer after a third drying. E. Spray a protective glaze onto the surface of the positioning dry granule layer, and after the fourth drying, obtain the digital mold positioning dry granule ceramic tile by firing and polishing in sequence. The printing areas of the protective glaze ink, the printing areas of the positioning adhesive, and the laying areas of the positioning dry granules are matched with each other. In step E, the raw materials for the protective glaze include a protective glaze base, a suspending agent, and water. The chemical composition of the protective glaze base, by mass percentage, includes 44-48% SiO2, 12-16% Al2O3, 4-8% CaO, 1-3% MgO, 2-4% K2O, 2-4% Na2O, 8-12% BaO, 2-4% SrO, and 3-6% ZnO.

[0008] Preferably, in step B, the raw materials of the digital glaze include glaze base material, ink removal agent, defoamer, methylcellulose and water, and the chemical composition of the glaze base material by mass percentage includes SiO2 58-62%, Al2O3 24-28%, CaO 1-3%, MgO 1-3%, K2O 0.1-2% and Na2O 4-7%.

[0009] Preferably, in steps C and D, the same inkjet printer is used to print oil-based protective glaze ink and positioning adhesive sequentially, and the speed of the inkjet printer is 20-25 m / min.

[0010] Preferably, in step B, the inkjet volume of the mold ink is 10–30 g / m³. 2 The specific gravity of the digital glaze is 1.50–1.55, and the glaze application rate is 530–612 g / m³. 2 .

[0011] Preferably, in step E, the specific gravity of the protective glaze is 1.20–1.25, and the glaze application rate is 285–326 g / m³. 2 .

[0012] Preferably, in step B, the drying temperature for the second drying is 80–100°C, and the drying time is 2–4 min. In step D, the drying temperature for the third drying is 100-120°C, and the drying time is 2-4 minutes. In step E, the drying temperature for the fourth drying is 80–100°C, and the drying time is 1–3 minutes.

[0013] Preferably, in step D, the amount of the positioning dry granules is 612–734 g / m³. 2 According to mass percentage, the chemical composition of the positioning dry granules includes 46-50% SiO2, 18-22% Al2O3, 4-7% CaO, 0.1-3% MgO, 2-5% K2O, 2-5% Na2O, 3-6% BaO, 4-6% SrO and 8-12% ZnO.

[0014] Preferably, in step D, the positioning dry granules, by mass percentage, comprise 5-10% of first granules of 100-120 mesh, 20-30% of second granules of >120 and ≤160 mesh, 40-50% of third granules of >160 and ≤200 mesh, and 15-25% of fourth granules of >200 and ≤250 mesh.

[0015] Preferably, it further includes step F, which is located between step B and step C: F. Print color ink on the surface of the digital mold layer to obtain an inkjet printing layer; C. Print an oil-based protective glaze ink on the surface of the inkjet printing layer to obtain a moisture isolation layer.

[0016] A digital mold-positioned dry granule ceramic tile that reduces prickly heat and pinholes is prepared using the above-described preparation method for digital mold-positioned dry granule ceramic tiles that reduce prickly heat and pinholes.

[0017] The technical solution provided by this invention may include the following beneficial effects: 1. To improve the defects of blistering and pinholes on the surface of ceramic tiles, this solution prints an oil-based protective glaze ink between the digital mold layer and the positioning dry granule layer. This forms a moisture isolation layer between the two water-based glazes, the digital glaze and the protective glaze. The moisture in the digital glaze and the protective glaze are separated by the oil-based protective glaze ink and evaporate independently. This prevents the migration of moisture and the accumulation of steam in the multiple layers of water-based glazes during the early stage of ceramic tile firing, thus avoiding blistering and pinhole defects caused by poor air venting.

[0018] 2. After introducing protective glaze ink as a moisture isolation layer, this solution also limits the chemical composition of the basic components in the protective glaze, adopting a high-barium formula system to moderately increase its high-temperature viscosity. The intention is that after the gas is discharged, the higher viscosity glaze can close to form a dense glaze surface, preventing secondary glaze defects such as glaze shrinkage and orange peel caused by excessive glaze thinning in the later stage. At the same time, it inhibits excessive flow of the glaze surface, reduces the spread of the glaze surface to the bottom layer of micro-cavities, and prevents the glaze with too strong fluidity from enlarging the micropores and forming visible defects. Detailed Implementation

[0019] This technical solution provides a method for preparing digital mold-positioned dry granule ceramic tiles that reduces prickly heat and pinholes, including the following steps: A. The billet is rolled into shape and dried for the first time to obtain the billet body; B. Print mold ink and spray digital glaze sequentially on the surface of the blank, and obtain the digital mold layer after a second drying. C. Print an oil-based protective glaze ink on the surface of the digital mold layer to obtain a moisture isolation layer; D. Sequentially print positioning adhesive and lay positioning dry granules on the surface of the moisture isolation layer, and obtain the positioning dry granule layer after a third drying. E. Spray a protective glaze onto the surface of the positioning dry granule layer, and after the fourth drying, obtain the digital mold positioning dry granule ceramic tile by firing and polishing in sequence. The printing areas of the protective glaze ink, the printing areas of the positioning adhesive, and the laying areas of the positioning dry granules are matched with each other. In step E, the raw materials for the protective glaze include a protective glaze base, a suspending agent, and water. The chemical composition of the protective glaze base, by mass percentage, includes 44-48% SiO2, 12-16% Al2O3, 4-8% CaO, 1-3% MgO, 2-4% K2O, 2-4% Na2O, 8-12% BaO, 2-4% SrO, and 3-6% ZnO.

[0020] To address the difficulty in air removal caused by the large thickness and quantity of the positioning dry granule layer, thereby improving surface defects such as blistering and pinholes in ceramic tiles, this technical solution proposes a method for preparing digital mold-positioned dry granule ceramic tiles that reduces blistering and pinholes. The method mainly includes five steps: A (pressing), B (preparing the digital mold layer), C (printing a moisture isolation layer), D (preparing the positioning dry granule layer), and E (spraying a protective glaze). The digital mold layer and the positioning dry granule layer serve as the effect layers of the ceramic tile, giving it a strong three-dimensional effect. It should be noted that the digital mold layer has a textured surface, formed by oil-based mold ink peeling away water-based digital glaze. The positioning dry granule layer also has an uneven textured structure due to the accumulation of positioning dry granules in the positioning adhesive area. Furthermore, the printing areas of the mold ink and the positioning adhesive can be determined according to a preset pattern. When these two printing areas overlap, the overlapping area has a superimposed effect of the mold texture formed by the digital mold layer and the texture structure formed by the positioning dry granule layer, further enhancing the richness of the three-dimensional effect of the ceramic tile.

[0021] During the ceramic tile firing process, the defects of blistering and pinholes on the tile surface are mainly caused by two factors: First, the body has a high density (e.g., the body is obtained through roll forming), resulting in few internal pores and limited and obstructed air venting channels; second, the glaze layer has a high moisture content, which rapidly vaporizes during the rapid heating phase of firing. When the gas generated during the firing process cannot escape through the dense body, it focuses at the glaze-body interface and breaks through the glaze layer. However, due to the large thickness and quantity of the dry granule layer, the gas cannot escape in time, thus forming areas prone to blistering and pinholes.

[0022] To improve surface defects such as blistering and pinholes in ceramic tiles, this solution first prints an oil-based protective glaze ink between the digital mold layer and the positioning dry granule layer. This forms a moisture barrier between the two water-based glazes, the digital glaze and the protective glaze. The moisture in the digital glaze and the protective glaze is separated by the oil-based protective glaze ink, allowing them to evaporate independently. This prevents the migration of moisture and the accumulation of steam from the multiple layers of water-based glazes during the initial firing stage of the tile, thus avoiding blistering and pinhole defects caused by poor venting. It should be noted that since blistering and pinhole defects are most prevalent in the area where the positioning dry granules are laid, this solution only prints the oil-based protective glaze ink in the area where the positioning dry granules are located to ensure effective control of the risk of blistering and pinholes in this high-risk area, while also considering the process difficulty and cost. In areas without the positioning dry granule layer, since there are no dry granules to obstruct venting, gas can escape more easily, having little impact on the overall surface effect of the tile.

[0023] It should be further explained that the oil-based protective glaze ink used in this solution is a commercially available functional material widely used in architectural ceramics. Unlike traditional water-based glazes, it employs an organic solvent system, and its common raw material composition includes inorganic powders, organic solvents, and additives. In this solution, in addition to acting as a moisture barrier layer, the inorganic powders in the protective glaze ink can also form a thin and dense glassy phase substrate during firing, thereby improving the bonding strength between the positioning dry particles and the digital surface glaze.

[0024] Furthermore, after introducing protective glaze ink as a moisture isolation layer, this solution also limits the chemical composition of the basic components (i.e., protective glaze base material) in the protective glaze, adopting a high-barium formulation system to moderately increase its high-temperature viscosity. This is intended so that after the gas is discharged, the higher viscosity glaze can close to form a dense glaze surface, preventing secondary glaze defects such as glaze shrinkage and orange peel caused by excessive glaze thinning in the later stage. At the same time, it inhibits excessive flow of the glaze surface, reduces the spread of tiny air pockets in the bottom layer of the glaze surface, and prevents the glaze with too strong fluidity from enlarging the micropores and forming visible defects.

[0025] To further explain, in step B, the raw materials of the digital glaze include glaze base material, ink removal agent, defoamer, methylcellulose and water, and the chemical composition of the glaze base material by mass percentage includes SiO2 58-62%, Al2O3 24-28%, CaO 1-3%, MgO 1-3%, K2O 0.1-2% and Na2O 4-7%.

[0026] In a preferred embodiment of this technical solution, the chemical composition of the basic component (i.e., the glaze base material) in the digital glaze is also defined. A high-silicon, high-alumina formulation system is adopted to ensure that it has a large high-temperature viscosity. On the one hand, this ensures that the digital mold layer after firing retains the required mold texture, and on the other hand, it suppresses the tiny bubbles generated when the blank is vented, preventing them from spreading upward to other layers.

[0027] To further explain, in steps C and D, the same inkjet printer is used to print oil-based protective glaze ink and positioning adhesive sequentially, and the speed of the inkjet printer is 20-25 m / min.

[0028] This facilitates the alignment of the protective glaze ink and positioning adhesive during printing, reducing process difficulty and equipment costs. Furthermore, optimizing the printing speed effectively prevents the positioning adhesive from drying too quickly, ensuring effective accumulation of the positioning particles and guaranteeing a three-dimensional effect for the positioning particle layer.

[0029] To further clarify, in step B, the inkjet volume of the mold ink is 10–30 g / m³. 2 The specific gravity of the digital glaze is 1.50–1.55, and the glaze application rate is 530–612 g / m³. 2 .

[0030] This helps ensure the rapid drying of the digital mold layer; otherwise, the glaze may be difficult to dry, reducing the bonding strength between the positioning dry granule layer and the digital surface glaze, which may subsequently cause the positioning dry granule layer to peel off.

[0031] To further clarify, in step E, the specific gravity of the protective glaze is 1.20–1.25, and the glaze application rate is 285–326 g / m³. 2 .

[0032] To further explain, in step B, the drying temperature for the second drying is 80-100°C, and the drying time is 2-4 minutes. In step D, the drying temperature for the third drying is 100-120°C, and the drying time is 2-4 minutes. In step E, the drying temperature for the fourth drying is 80–100°C, and the drying time is 1–3 minutes.

[0033] Optimizing the drying temperature and time in steps B and E is beneficial for quickly drying the moisture in the water-based glaze; optimizing the drying temperature and time in step D can achieve stable laying of the positioning dry particles and avoid peeling of the positioning dry particle layer when the protective glaze with high moisture content is sprayed later.

[0034] To further clarify, in step D, the amount of the positioning dry granules laid is 612–734 g / m³. 2 According to mass percentage, the chemical composition of the positioning dry granules includes 46-50% SiO2, 18-22% Al2O3, 4-7% CaO, 0.1-3% MgO, 2-5% K2O, 2-5% Na2O, 3-6% BaO, 4-6% SrO and 8-12% ZnO.

[0035] In a preferred embodiment of this technical solution, the positioning dry granules adopt a chemical composition of a high-alumina and high-zinc formula system, which can maintain transparency and semi-emulsion state even with a large accumulation thickness, thereby enhancing the three-dimensional texture of the ceramic tile.

[0036] To further explain, in step D, according to the mass percentage, the positioning dry granules include 5-10% of the first granules with a mesh size of 100-120, 20-30% of the second granules with a mesh size of >120 and ≤160, 40-50% of the third granules with a mesh size of >160 and ≤200, and 15-25% of the fourth granules with a mesh size of >200 and ≤250.

[0037] In this way, the three-dimensional effect richness of the positioning dry granule layer can be provided.

[0038] To further explain, it also includes step F, which is located between steps B and C: F. Print color ink on the surface of the digital mold layer to obtain an inkjet printing layer; C. Print an oil-based protective glaze ink on the surface of the inkjet printing layer to obtain a moisture isolation layer.

[0039] This solution also allows for the application of colored ink before the step of printing the protective glaze ink, thus giving the tiles a strong dual decorative effect in terms of both visual appeal and tactile feel.

[0040] A digital mold-positioned dry granule ceramic tile that reduces prickly heat and pinholes is prepared using the above-described preparation method for digital mold-positioned dry granule ceramic tiles that reduce prickly heat and pinholes.

[0041] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0042] Example A. The billet is rolled into shape and dried for the first time to obtain the billet body; B. Print mold ink and spray digital glaze sequentially on the surface of the blank, and obtain the digital mold layer after a second drying. C. Print an oil-based protective glaze ink on the surface of the digital mold layer to obtain a moisture isolation layer; D. Sequentially print positioning adhesive and lay positioning dry granules on the surface of the moisture isolation layer, and obtain the positioning dry granule layer after a third drying. E. Spray a protective glaze onto the surface of the positioning dry granule layer, and after the fourth drying, obtain digital mold positioning dry granule ceramic tiles through firing and polishing. After observation, the ceramic tiles have very few blemishes and pinholes.

[0043] The printing areas of the protective glaze ink, the printing areas of the positioning adhesive, and the laying areas of the positioning dry granules are matched with each other.

[0044] In step B, the raw materials for the digital glaze include a glaze base, an ink-removing agent, a defoamer, methylcellulose, and water. The chemical composition of the glaze base, by mass percentage, includes 59.3% SiO2, 27.8% Al2O3, 2.8% CaO, 1.2% MgO, 1.6% K2O, and 6.2% Na2O, with the remainder being unavoidable impurities in the formulation. The inkjet volume of the mold ink is 15 g / m³. 2 The specific gravity of the digital glaze is 1.50, and the glaze application rate is 600 g / m³. 2 The second drying process was carried out at a temperature of 80°C for 4 minutes.

[0045] In steps C and D, the same inkjet printer is used to sequentially print oil-based protective glaze ink and positioning adhesive, with the printer speed at 22 m / min. The third drying step is performed at 100°C for 4 minutes. The amount of positioning dry granules applied is 650 g / m³. 2 The chemical composition of the targeted dry granules, by mass percentage, includes 47.2% SiO2, 20.6% Al2O3, 4.5% CaO, 1.8% MgO, 2.3% K2O, 3.6% Na2O, 4.7% BaO, 4.3% SrO, and 10.2% ZnO, with the remainder being unavoidable impurities in the formulation system. By mass percentage, the targeted dry granules comprise 5% of first-stage particles (100-120 mesh), 25% of second-stage particles (mesh > 120 and ≤ 160 mesh), 50% of third-stage particles (mesh > 160 and ≤ 200 mesh), and 20% of fourth-stage particles (mesh > 200 and ≤ 250 mesh).

[0046] In step E, the raw materials for the protective glaze include a protective glaze base, a suspending agent, and water. The chemical composition of the protective glaze base, by mass percentage, includes 45.6% SiO2, 15.3% Al2O3, 7.2% CaO, 2.1% MgO, 3.6% K2O, 3.8% Na2O, 11.8% BaO, 3.9% SrO, and 5.8% ZnO. The remaining content represents unavoidable impurities in the formulation system. The specific gravity of the protective glaze is 1.20, and the spraying amount is 300 g / m³. 2 The fourth drying process was carried out at a temperature of 80°C for 3 minutes.

[0047] Comparative Example 1) The billet is rolled into shape and dried for the first time to obtain the billet body; 2) Print mold ink and spray digital glaze on the surface of the blank in sequence, and obtain the digital mold layer after a second drying; 3) Sequentially print positioning adhesive and lay positioning dry granules on the surface of the digital mold layer, and obtain the positioning dry granule layer after a third drying. 4) Spray a protective glaze onto the surface of the positioning dry granule layer, and after the fourth drying, obtain digital mold positioning dry granule ceramic tile through firing and polishing. After observation, the ceramic tile has a lot of blistering and pinholes.

[0048] The printing area of ​​the positioning adhesive and the laying area of ​​the positioning dry granules are matched with each other; In step 2), the raw materials for the digital glaze include a glaze base, an ink-removing agent, a defoamer, methylcellulose, and water. The chemical composition of the glaze base, by mass percentage, is a conventional composition found in existing technologies, including SiO2: 50.93%, Al2O3: 21.01%, Fe2O3: 0.20%, CaO: 8.60%, MgO: 3.67%, K2O: 1.69%, Na2O: 1.97%, BaO: 1.96%, ZnO: 0.96%, ZrO2: 0.38%, and a loss on ignition of 8.44%. The remaining content represents unavoidable impurities in the formulation system. The inkjet volume of the mold ink is 15 g / m³. 2 The specific gravity of the digital glaze is 1.50, and the glaze application rate is 600 g / m³. 2 The second drying process was carried out at a temperature of 80°C for 4 minutes.

[0049] In step 3), the third drying process is carried out at a temperature of 100°C for 4 minutes. The amount of the positioned dry granules is 650 g / m³. 2The chemical composition of the targeted dry granules, by mass percentage, includes 47.2% SiO2, 20.6% Al2O3, 4.5% CaO, 1.8% MgO, 2.3% K2O, 3.6% Na2O, 4.7% BaO, 4.3% SrO, and 10.2% ZnO, with the remainder being unavoidable impurities in the formulation system. By mass percentage, the targeted dry granules comprise 5% of first-stage particles (100-120 mesh), 25% of second-stage particles (mesh > 120 and ≤ 160 mesh), 50% of third-stage particles (mesh > 160 and ≤ 200 mesh), and 20% of fourth-stage particles (mesh > 200 and ≤ 250 mesh).

[0050] In step 4), the raw materials for the protective glaze include a protective glaze base, a suspending agent, and water. The chemical composition of the protective glaze base, by mass percentage, is a conventional composition found in existing technologies, including SiO2: 52.90%, Al2O3: 17.41%, CaO: 6.66%, MgO: 1.25%, K2O: 3.87%, Na2O: 2.40%, BaO: 6.78%, ZnO: 4.40%, SrO: 4.08%, and a loss on ignition of 0.10%. The remaining content represents unavoidable impurities in the formulation system. The specific gravity of the protective glaze is 1.20, and the spraying amount is 300 g / m³. 2 The fourth drying process was carried out at a temperature of 80°C for 3 minutes.

[0051] 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 preparing digitally molded, positioned dry-granule ceramic tiles that reduces prickly heat and pinholes, characterized in that, Includes the following steps: A. The billet is rolled into shape and dried for the first time to obtain the billet body; B. Print mold ink and spray digital glaze sequentially on the surface of the blank, and obtain the digital mold layer after a second drying. C. Print an oil-based protective glaze ink on the surface of the digital mold layer to obtain a moisture isolation layer; D. Sequentially print positioning adhesive and lay positioning dry granules on the surface of the moisture isolation layer, and obtain the positioning dry granule layer after a third drying. E. Spray a protective glaze onto the surface of the positioning dry granule layer, and after the fourth drying, obtain the digital mold positioning dry granule ceramic tile by firing and polishing in sequence. The printing areas of the protective glaze ink, the printing areas of the positioning adhesive, and the laying areas of the positioning dry granules are matched with each other. In step E, the raw materials for the protective glaze include a protective glaze base, a suspending agent, and water. The chemical composition of the protective glaze base, by mass percentage, includes 44-48% SiO2, 12-16% Al2O3, 4-8% CaO, 1-3% MgO, 2-4% K2O, 2-4% Na2O, 8-12% BaO, 2-4% SrO, and 3-6% ZnO.

2. The method for preparing a digital mold-positioned dry-granule ceramic tile with reduced prickly heat and pinholes according to claim 1, characterized in that, In step B, the raw materials of the digital glaze include glaze base material, ink removal agent, defoamer, methylcellulose and water, and the chemical composition of the glaze base material by mass percentage includes SiO2 58-62%, Al2O3 24-28%, CaO 1-3%, MgO 1-3%, K2O 0.1-2% and Na2O 4-7%.

3. The method for preparing a digital mold-positioned dry-granule ceramic tile with reduced prickly heat and pinholes according to claim 1, characterized in that, In steps C and D, the same inkjet printer is used to print oil-based protective glaze ink and positioning adhesive sequentially, and the speed of the inkjet printer is 20-25 m / min.

4. The method for preparing a digital mold-positioned dry-granule ceramic tile with reduced prickly heat and pinholes according to claim 1, characterized in that, In step B, the inkjet volume of the mold ink is 10–30 g / m³. 2 The specific gravity of the digital glaze is 1.50–1.55, and the glaze application rate is 530–612 g / m³. 2 .

5. The method for preparing a digital mold-positioned dry-granule ceramic tile with reduced prickly heat and pinholes according to claim 1, characterized in that, In step E, the specific gravity of the protective glaze is 1.20–1.25, and the glaze application rate is 285–326 g / m³. 2 .

6. The method for preparing a digital mold-positioned dry-granule ceramic tile with reduced prickly heat and pinholes according to claim 1, characterized in that, In step B, the drying temperature for the second drying is 80-100℃, and the drying time is 2-4 minutes. In step D, the drying temperature for the third drying is 100-120°C, and the drying time is 2-4 minutes. In step E, the drying temperature for the fourth drying is 80–100°C, and the drying time is 1–3 minutes.

7. The method for preparing a digital mold-positioned dry-granule ceramic tile with reduced prickly heat and pinholes according to claim 1, characterized in that, In step D, the amount of the positioning dry granules laid is 612–734 g / m³. 2 The chemical composition of the positioning dry granules, by mass percentage, includes 46-50% SiO2, 18-22% Al2O3, 4-7% CaO, 0.1-3% MgO, 2-5% K2O, 2-5% Na2O, 3-6% BaO, 4-6% SrO, and 8-12% ZnO.

8. The method for preparing a digital mold-positioned dry-granule ceramic tile with reduced prickly heat and pinholes according to claim 1, characterized in that, In step D, according to the mass percentage, the positioning dry granules include 5-10% of the first granules with a mesh size of 100-120, 20-30% of the second granules with a mesh size of >120 and ≤160, 40-50% of the third granules with a mesh size of >160 and ≤200, and 15-25% of the fourth granules with a mesh size of >200 and ≤250.

9. The method for preparing a digital mold-positioned dry-granule ceramic tile with reduced prickly heat and pinholes according to claim 1, characterized in that, It also includes step F, which is located between steps B and C: F. Print color ink on the surface of the digital mold layer to obtain an inkjet printing layer; C. Print an oil-based protective glaze ink on the surface of the inkjet printing layer to obtain a moisture isolation layer.

10. A digital mold-positioned dry-granule ceramic tile that reduces prickly heat and pinholes, characterized in that, It is prepared using the preparation method of digital mold positioning dry granule ceramic tile for reducing prickly heat and pinholes as described in any one of claims 1 to 9.