Preparation method of deep-color full-glazed ceramic tile and deep-color full-glazed ceramic tile

Abstract

The invention provides a preparation method of a deep-color full-glazed ceramic tile and the deep-color full-glazed ceramic tile, and the preparation method of the deep-color full-glazed ceramic tile comprises the following steps: preparing a ceramic tile green body, and applying ground coat on the ceramic tile green body to form a ground coat layer; inkjet decorative printing is conducted on the ground coat layer, meanwhile, functional ink is printed, and a pattern decorative layer is formed; the pattern decoration layer is dried, isolation glaze is applied, and an isolation glaze layer is formed; fully polished glaze is applied to the isolation glaze layer to form a fully polished glaze layer, and then the fully polished glaze layer is fired to obtain the deep-color fully polished ceramic tile. Wherein the thermal expansion coefficient of the ground glaze layer is between the thermal expansion coefficient of the ceramic tile green body and the thermal expansion coefficient of the full-polished glaze layer. According to the application, in the firing process, thermal expansion coefficients among the ceramic tile green body, the ground glaze and the full-polished glaze are in uniform transition, deformation caused by stress concentration due to violent change is avoided, and the problems of edge warping and unevenness of the deep-color full-polished glaze ceramic tile are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of tile production, in particular to a preparation method of a dark-colored fully-glazed tile and the dark-colored fully-glazed tile. Background Art

[0002] Dark, fully glazed tiles are popular for their high color saturation, rich colors, and diverse textures, creating a luxurious decor. To achieve a strong visual experience, dark, fully glazed tiles generally have a high gloss, so the glaze applied to their surface must be low-temperature glaze. This allows for a larger glass phase to form on the surface during the firing process, increasing the gloss of the polished product. Because glazes fired at low temperatures typically have a high degree of vitrification and a relatively compact internal structure, their expansion coefficient is relatively small. This makes dark, fully glazed tiles prone to thermal expansion coefficient mismatches between the glaze and the base. Specifically, the lower the firing temperature of the glaze relative to the base, the more pronounced the thermal expansion coefficient mismatch between the base and glaze becomes. Although ordinary ceramic products also have the problem of body-glaze mismatch, the problem of body-glaze mismatch of dark fully-glazed tiles is particularly prominent. This is because ordinary ceramic products can be solved simply by adjusting the formula to increase the glaze firing temperature, while dark fully-glazed tiles need to take into account both the glaze firing temperature and the body-glaze matching. In order to obtain a high-gloss glaze effect, low-temperature glaze must be used, which makes the problem of mismatch between the thermal expansion coefficient of the glaze and the body difficult to solve, resulting in the tiles being easy to deform, easy to warp and uneven, and because of the poor brick shape, it is difficult to obtain a uniform polishing effect, resulting in the product having yin and yang colors, that is, color difference problems.

[0003] Therefore, the existing technology has defects and needs to be improved and developed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a preparation method of dark full-glazed tiles and dark full-glazed tiles in response to the above-mentioned defects of the prior art, aiming to solve the problems in the prior art that dark full-glazed tiles are easy to deform, easy to warp and uneven.

[0005] The technical solutions adopted by the present invention to solve the technical problems are as follows:

[0006] The first embodiment of the present application provides a method for preparing dark fully glazed ceramic tiles, which comprises:

[0007] preparing a ceramic tile body, and applying a ground glaze on the ceramic tile body to form a ground glaze layer;

[0008] Performing inkjet decorative printing on the base glaze layer and simultaneously printing functional ink to form a pattern decoration layer;

[0009] drying the pattern decoration layer and applying an isolation glaze to form an isolation glaze layer;

[0010] Applying full-polished glaze on the isolation glaze layer to form a full-polished glaze layer and then firing to obtain a dark full-polished glaze ceramic tile;

[0011] Wherein, the thermal expansion coefficient of the bottom glaze layer is between the thermal expansion coefficient of the ceramic tile body and the thermal expansion coefficient of the full-polished glaze layer.

[0012] In one embodiment of the present application, the raw materials of the ceramic tile body include, by mass percentage:

[0013] High alumina washed mud 20-30%, raw ore mud 10-15%, ball clay 3-9%, bentonite 5-10%, tonite powder 20-30%, malachite powder 5-10%, potassium sand and stone powder 3-6%, Xingning water abrasive 10-15%, magnesia 2-6%.

[0014] In one embodiment of the present application, the raw materials of the base glaze include, by mass percentage:

[0015] Zinc oxide 1-2%, zirconium silicate 4-7%, potassium feldspar 20-30%, sodium feldspar 30-40%, kaolin 8-15%, calcined kaolin 5-10%, frit 10-20%, aluminum oxide 1-4%, dolomite 5-10%;

[0016] wherein the thermal expansion coefficient of the frit is within a preset low expansion coefficient range;

[0017] The chemical composition of the base glaze, calculated by mass percentage, comprises:

[0018] SiO2 55~65%, Al2O3 18~22%, Fe2O3 0.1~0.2%, CaO 3~6%, MgO 1~3%, Na2O 1~4%, K2O 2~5%, ZnO 2~5%, BaO 0~2%.

[0019] In one embodiment of the present application, the raw materials for the full-polished glaze include, by mass percentage:

[0020] Zinc oxide 4-6%, sodium fluorosilicate 3-5%, potassium feldspar 25-30%, sodium feldspar 10-15%, kaolin 6-10%, quartz 5-10%, high calcium and high barium frit 20-30%, calcite 8-15%, talc 6-10%;

[0021] The chemical composition of the full-polished glaze is calculated by mass percentage and includes:

[0022] SiO2 50~60%, Al2O3 10~15%, Fe2O3 0.1~0.2%, CaO 10~15%, MgO1~3%, K2O 2~4%, Na2O 1~3%, ZnO 5~10%, BaO 7~12%.

[0023] In one embodiment of the present application, preparing a ceramic tile body comprises:

[0024] Prepare green body powder according to the raw material formula of ceramic tile green body, wherein the whiteness of the green body powder is 20-30 degrees and the particle size of the powder is 0.3-0.6 mm;

[0025] Pressing the green body powder into a shape, and drying it at a drying temperature of 90 to 130° C. for 50 to 70 minutes to obtain a ceramic tile green body;

[0026] The thermal expansion coefficient of the ceramic tile body is 7.0×10 -6 / ℃~7.5×10 -6 / ℃.

[0027] In one embodiment of the present application, applying a ground glaze on the ceramic tile body to form a ground glaze layer comprises:

[0028] Applying a base glaze to the ceramic tile body by a bell-shaped glaze pouring method, with a glaze specific gravity of 1.72 to 1.80 and a glaze amount of 500 to 600 g / m2 to form a base glaze layer;

[0029] The thermal expansion coefficient of the base glaze is 6.8×10 -6 / ℃~7.2×10 -6 / ℃.

[0030] In one embodiment of the present application, the functional ink includes: white ink, glossy ink and / or matte ink.

[0031] In one embodiment of the present application, the pattern decoration layer is dried and an isolation glaze is applied to form an isolation glaze layer, comprising:

[0032] When drying the pattern decoration layer, the pattern decoration layer is dried using a plurality of open flame guns added to the glaze line drying kiln;

[0033] Use a rubber roller to roll the isolation glaze, the glaze specific gravity is 1.45-1.55, the glaze amount is 100-150 g / m2, to form an isolation glaze layer;

[0034] The isolation glaze is prepared using ethylene glycol as a solvent; the chemical composition of the isolation glaze, calculated by mass percentage, includes:

[0035] SiO2 45~55%, Al2O3 10~15%, CaO 10~15%, MgO 1~3%, K2O 2~4%, Na2O 2~4%, ZnO 5~10%, BaO 7~12%.

[0036] In one embodiment of the present application, a full-polished glaze is applied on the isolation glaze layer to form a full-polished glaze layer and then fired to obtain a dark full-polished glaze tile, comprising:

[0037] Applying full-polished glaze on the isolation glaze layer by a bell-shaped glaze pouring method, with a glaze specific gravity of 1.72 to 1.80 and a glaze amount of 400 to 500 grams per square meter to form a full-polished glaze layer;

[0038] The ceramic tiles are fired at a temperature of 1150-1220°C for 60-100 minutes, and then polished and waxed to obtain dark fully glazed ceramic tiles.

[0039] The thermal expansion coefficient of the full-glaze is 6.5×10 -6 / ℃~6.8×10 -6 / ℃.

[0040] A second aspect of the present application provides a dark fully glazed ceramic tile, wherein the dark fully glazed ceramic tile is prepared by the dark fully glazed ceramic tile preparation method as described above.

[0041] The present application discloses a preparation method of a dark fully glazed ceramic tile and a dark fully glazed ceramic tile. The preparation method of the dark fully glazed ceramic tile comprises: preparing a ceramic tile body, applying a base glaze on the ceramic tile body to form a base glaze layer; inkjet decorative printing on the base glaze layer, and simultaneously printing functional ink to form a pattern decoration layer; drying the pattern decoration layer, and applying an isolation glaze to form an isolation glaze layer; applying a full glaze on the isolation glaze layer to form a full glaze layer and then firing to obtain a dark fully glazed ceramic tile; wherein the thermal expansion coefficient of the base glaze layer is between the thermal expansion coefficient of the ceramic tile body and the thermal expansion coefficient of the full glaze layer. The thermal expansion coefficient of the base glaze layer of the present application is between the thermal expansion coefficient of the ceramic tile body and the thermal expansion coefficient of the full glaze layer, so that during the firing process, the thermal expansion coefficients of the three layers of the ceramic tile body, the base glaze, and the full glaze are uniformly transitioned, avoiding deformation caused by stress concentration due to drastic changes, and avoiding the problem of warping and unevenness of the dark fully glazed ceramic tile. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The present invention is a flowchart of a preferred embodiment of a method for preparing dark fully glazed ceramic tiles. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present invention more clear and distinct, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0044] Existing dark, fully polished glazed tiles are sensitive to raw materials and firing conditions, resulting in color variations. High temperatures in the glaze layer can easily generate gas, forming pinholes or bubbles. This results in a low quality rating and a relatively high manufacturing cost. Most importantly, dark, fully polished glazes are prone to deformation, warping, and uneven edges, while also having a low glaze surface hardness, making them susceptible to wear and tear after long-term use.

[0045] The current market lacks dark, fully glazed tiles that can achieve low cost, high quality, smooth laying, good wear resistance, and high clarity. The present application embodiment reduces production costs and improves product quality from the source of the production process, and enhances the flatness, anti-fouling, wear resistance, and clarity of dark, fully glazed products.

[0046] Specifically, the embodiments of the present application aim to solve the following problems:

[0047] First, the problem of deformation and unevenness when laying dark-colored fully glazed ceramic tiles. The embodiment of the present application reduces the thermal expansion coefficient of the ceramic tile body, and designs and adjusts a special base glaze and fully glaze that are suitable for the ceramic tile body, so that the expansion coefficients of the three layers of ceramic tile body, base glaze and fully glaze are evenly transitioned during the firing process, avoiding deformation caused by stress concentration due to drastic changes. The kiln flatness of the embodiment of the present application can achieve concave / convex ≤ 0.2 (referring to the maximum height difference of the concave or convex at any position within the range of the detected surface is no more than 0.2mm), and batch deviation ≤ 0.4 (referring to the products in the same batch, the maximum dimensional deviation between each part is no more than 0.4mm.), which is much higher than the current market industry control standards of concave / convex ≤ 0.4 and batch deviation ≤ 0.6.

[0048] Secondly, dark-colored fully glazed tiles have low overall quality ratings and high manufacturing costs. By adjusting the basic formulas for the tile body, base glaze, and fully glazed tiles, reducing the amount of carbonate materials added, and prioritizing the use of ternary aluminum raw materials instead of binary aluminum raw materials in the glaze raw materials, the initial melting temperature and melting range are increased, and the chemical stability is improved, thereby greatly reducing impurities, bulges, pinholes, bubbles, and other defects generated during the firing process. The overall quality rating of the embodiments of the present application can be increased from the industry-wide average of 92% to 97%, the overall manufacturing cost can be reduced by 20%, and the market competitiveness is greatly enhanced.

[0049] Third, the problem of poor clarity and transparency of dark-colored fully-glazed tiles: In order to ensure surface hardness and wear resistance, traditional dark-colored fully-glazed tiles generally increase the thickness of the glaze layer and the aluminum content to ensure wear resistance. However, it is precisely because of the thick glaze layer and high aluminum content that the tiles become turbid and have poor transparency during the firing process, resulting in poor pattern clarity and transparency. The embodiment of the present application optimizes the basic formula of the fully-glazed glaze, increases the content of the glass former SiO2, and uses high calcium and high barium to improve the hardness of the glaze surface, which can significantly reduce the aluminum content in the formula. At the same time, because the hardness and wear resistance problems are solved, the thickness of the glaze layer can also be reduced by 15%, thereby making the dark-colored fully-glazed tiles have high clarity and high transparency.

[0050] Fourth, the anti-fouling and wear-resistant performance of dark-colored fully-glazed tiles. The embodiment of this application adjusts the special full-glazed base formula by increasing the introduction of high-hardness materials such as aluminum silicates and calcium-aluminum compounds to replace low-hardness materials such as aluminum-silicon compounds and aluminum-magnesium compounds, thereby improving the wear resistance of the full-glazed glaze. While ensuring high clarity and high transparency, the dark-colored fully-glazed tiles of the embodiment of this application can achieve a glaze hardness of above national standard level 4 and a wear resistance of above level 3.

[0051] See Figure 1 , Figure 1 This is a flow chart of the method for preparing dark fully glazed tiles in the present invention. Figure 1 As shown, the preparation method of the dark fully glazed ceramic tile according to the embodiment of the present invention comprises the following steps:

[0052] Step S100: preparing a ceramic tile body, and applying a ground glaze on the ceramic tile body to form a ground glaze layer;

[0053] Step S200, performing inkjet decorative printing on the base glaze layer and simultaneously printing functional ink to form a pattern decoration layer;

[0054] Step S300: drying the pattern decoration layer and applying an isolation glaze to form an isolation glaze layer;

[0055] Step S400, applying full-polished glaze on the isolation glaze layer, forming a full-polished glaze layer and then firing to obtain a dark full-polished glazed tile; wherein the thermal expansion coefficient of the base glaze layer is between the thermal expansion coefficient of the tile body and the thermal expansion coefficient of the full-polished glaze layer.

[0056] The thermal expansion coefficient of the base glaze layer in the embodiment of the present application is between the thermal expansion coefficient of the ceramic tile body and the thermal expansion coefficient of the full-polished glaze layer, so that during the firing process, the thermal expansion coefficients of the three layers of the ceramic tile body, the base glaze and the full-polished glaze are evenly transitioned, avoiding deformation caused by stress concentration due to drastic changes, and avoiding the problem of warping and unevenness of dark full-polished glazed tiles.

[0057] Dark fully glazed tiles generally use high gloss to give the product a high sense of transparency, but the high gloss of dark glaze means a lower glaze temperature. Low glaze temperature is bound to bring about the problem of mismatch between the expansion coefficients of the body and glaze, causing the product to be easily deformed and have color difference. The traditional method can only solve the problem of mismatch between the expansion coefficients of the body and glaze by increasing the glaze temperature, thereby improving the flatness of the product and solving the color difference problem, but doing so will reduce the gloss of the product and cause poor glaze transparency.

[0058] Specifically, a low glaze temperature means that the temperature range for the formation of the glass phase during firing is narrow, which can easily lead to uneven glaze flow, and "orange peel texture" or water ripples are likely to appear after glazing, affecting the visual effect. Therefore, the amount of glazing is usually increased to make the glaze layer thick enough, giving the polishing process more cutting volume to ensure flatness and avoid orange peel texture or water ripples. However, a sufficiently thick glaze layer will cause the viscosity of the glaze to be too high, affecting the pores during firing, forming pinholes or prickly heat bubbles, which will lead to problems such as low overall quality rate of dark fully polished glazes. The higher the glaze temperature, the more sensitive it is to the firing temperature, and the more likely it is to have the risk of color difference due to the temperature difference of the kiln. At the same time, due to the reduction of the glass phase component, the glaze structure is rougher, and the glaze is more uneven after polishing, and the orange peel texture or water ripples will be worse. If you blindly add a layer of glaze to solve the water ripples, it will lead to more pinholes and prickly heat bubbles, and the quality rate is poor. This application first solves the matching between the expansion coefficients of the body and glaze to make the tiles more flat, and then solves the problems of yellow edges and color difference of the polished glaze. On this basis, high-calcium and high-barium frits are introduced to solve the problem of the difficulty in balancing the high hardness and high transparency of the full-polished glaze. This achieves the high clarity and high transparency of dark full-polished glazed tiles while maintaining high hardness and high wear resistance.

[0059] This application adjusts the formula of the blank, base glaze and full-polished glaze to achieve a uniform transition of the thermal expansion coefficients between the three layers of the tile blank, base glaze and full-polished glaze during the firing process, avoiding deformation caused by stress concentration due to drastic changes, and avoiding the problem of warping and unevenness of dark full-polished glazed tiles.

[0060] In the embodiment of the present application, the raw materials of the ceramic tile body include, by mass percentage:

[0061] 20-30% high-alumina washed mud, 10-15% raw ore mud, 3-9% ball clay, 5-10% bentonite, 20-30% tonite powder, 5-10% malachite powder, 3-6% potash sand and stone powder, 10-15% Xingning water abrasive, and 2-6% magnesia. The chemical composition of some of the raw materials for the blanks is shown in Table 1, calculated by mass percentage. Any percentage not meeting 100% is impurity.

[0062] Table 1

[0063]

[0064]

[0065] Specifically, high-alumina water-washed mud is rich in alumina, and the linear expansion coefficient of alumina is low; magnesium oxide is introduced through magnesia, and the expansion coefficient of magnesium oxide is low.

[0066] This application adjusts the formula of the tile body and uses magnesia to introduce alkaline earth metals such as calcium and magnesium to replace part of the alkali metals such as potassium sodium stone powder as flux, thereby reducing the expansion coefficient. At the same time, bentonite is used instead of kaolin as flux to reduce the expansion coefficient.

[0067] In a specific embodiment, the chemical composition of the ceramic tile body, calculated by mass percentage, includes: loss on ignition 5.25%, SiO2 66.14%, Al2O3 20.08%, Fe2O3 1.49%, CaO 0.42%, MgO 1.49%, K2O2.49%, Na2O 2.14%, and the remainder is impurities.

[0068] In one embodiment, the raw materials of the base glaze include, by mass percentage:

[0069] Zinc oxide 1-2%, zirconium silicate 4-7%, potassium feldspar 20-30%, sodium feldspar 30-40%, kaolin 8-15%, calcined kaolin 5-10%, frit 10-20%, aluminum oxide 1-4%, dolomite 5-10%;

[0070] Wherein, the thermal expansion coefficient of the frit is within a preset low expansion coefficient range.

[0071] The chemical composition of the frit, calculated by mass percentage, includes: SiO2 48.1%, Al2O3 21.8%, Fe2O3 0.21%, CaO 15.9%, MgO 0.8%, K2O 3.5%, Na2O 0.7%, B2O3 0.7%, ZnO 7.4%, and BaO 0.7%.

[0072] The chemical composition of the base glaze, calculated by mass percentage, comprises:

[0073] SiO2 55~65%, Al2O3 18~22%, CaO 3~6%, MgO 1~3%, Na2O 1~4%, K2O 2~5%, ZnO 2~5%, BaO 0~2%.

[0074] Specifically, the low-expansion frit forms a low-expansion glass network in the glaze layer, offsetting the high expansion of minerals such as quartz; calcined kaolin generates mullite, further reducing expansion; the mixture of potassium feldspar and sodium feldspar can optimize the balance between the glaze's melting temperature and expansion, because potassium feldspar has a large linear expansion coefficient and a higher melting point than sodium feldspar, while sodium feldspar has a small linear expansion coefficient and a lower melting point than potassium feldspar. Replacing potassium feldspar with part of sodium feldspar can reduce the linear expansion coefficient and melting temperature, and vice versa, that is, adjusting the ratio of potassium feldspar to sodium feldspar, or replacing potassium feldspar with calcium and magnesium can also reduce the linear expansion coefficient and increase the melting temperature; zirconium silicate acts as an inert particle in the glaze, inhibiting overall expansion while not participating in the glass phase reaction. Therefore, the base glaze of this application has a low thermal expansion coefficient.

[0075] Furthermore, zirconium silicate provides a strong opacifying effect, leaving the glaze white and providing a pure background for color development. It also protects the colorant from damage by high temperatures, resulting in more vivid colors. Zinc oxide forms a stable spinel structure with transition metal ions such as cobalt and chromium, enhancing color intensity, smoothing the glaze surface, and reducing light scattering for a more vibrant color. Therefore, the base glaze of this application exhibits excellent color development performance.

[0076] The base glaze formula of the embodiment of the present application can be adapted to the ceramic tile body, and the base glaze has a low thermal expansion coefficient and good color development performance.

[0077] In a specific embodiment, the chemical composition of the base glaze, calculated by mass percentage, includes:

[0078] Loss on ignition 4.89%, SiO2 59.22%, Al2O3 19.86%, Fe2O3 0.19%, CaO 4.21%, MgO1.81%, K2O 4.78%, Na2O 1.74%, ZnO 2.63%, BaO 0.31%, and the remainder is impurities.

[0079] In the embodiment of the present application, the raw materials for the full-polished glaze include, by mass percentage:

[0080] Zinc oxide 4-6%, sodium fluorosilicate 3-5%, potassium feldspar 25-30%, sodium feldspar 10-15%, kaolin 6-10%, quartz 5-10%, high calcium and high barium frit 20-30%, calcite 8-15%, talc 6-10%.

[0081] The chemical composition of the high-calcium and high-barium frit includes, by mass percentage, SiO2 40.42%, Al2O3 14.68%, BaO 24.7%, CaO 13.36%, MgO 2.5%, K2O 0.17%, Na2O 2.71%, B2O3 0.49%, ZnO 0.05%, Fe2O3 0.1%, and the remainder is impurities.

[0082] The chemical composition of the full-polished glaze is calculated by mass percentage and includes:

[0083] SiO2 50~60%, Al2O3 10~15%, CaO 10~15%, MgO 1~3%, K2O 2~4%, Na2O 1~3%, ZnO 5~10%, BaO 7~12%.

[0084] The fully polished glaze of the embodiment of the present application introduces raw materials such as ternary aluminum glaze such as kaolin, sodium fluorosilicate, and high calcium and high barium frit after melting to replace traditional binary aluminum such as alumina and aluminum hydroxide to improve the hardness, wear resistance and chemical stability of the glaze, increase the SiO2 content, and use high calcium and high barium to improve the hardness of the glaze, so as to achieve high hardness and high wear resistance under low aluminum content. Because the hardness and wear resistance problems are solved, the high clarity and high transparency of dark fully polished glazed tiles are achieved. The fully polished glaze has high hardness (hardness level 4-5), high transparency, and high wear resistance (wear resistance level 3 1500 revolutions) performance.

[0085] Specifically, the present application introduces sodium fluorosilicate into the full-polished glaze to reduce the melting temperature of the glaze and the viscosity of the glaze layer. The gas released at high temperature can bring out the bubbles in the glaze, reduce pinhole defects, and be more conducive to exhaust. Sodium fluorosilicate changes the ratio of SiO2 and Na2O in the glaze during firing, which better matches the expansion rate of the body while promoting the vitrification of the glaze layer, strengthening the microstructure of the glaze layer, and enhancing its wear resistance and light transmittance. The full-polished glaze tiles in this application can achieve high transparency and high wear resistance at a gloss of 30 to 100 degrees. However, most of the existing dark full-polished glazes can only achieve high transparency at 70 to 100 degrees and cannot achieve high wear resistance at the same time. This application introduces more high-hardness materials such as aluminum silicates and calcium-aluminum compounds into the full-polished glaze to replace low-hardness materials such as aluminum-silicon compounds and aluminum-magnesium compounds, while increasing the SiO2 content, using high calcium and high barium to improve the glaze hardness, adding fluxing agents such as ZnO to promote the escape of bubbles, and the glaze layer thickness can also be reduced by 15-20%, thereby achieving high hardness and high wear resistance while still maintaining high clarity and high transparency of dark full-polished glazed tiles.

[0086] Therefore, this application not only solves the problem of mismatch in expansion coefficients of body and glaze, making the product have better flatness and no obvious color difference, but also enables dark fully polished glazed tiles to have the characteristics of high transparency, high wear resistance and high clarity.

[0087] In a specific embodiment, the chemical composition of the full-polished glaze comprises, by mass percentage:

[0088] Loss on ignition 2.8%, SiO2 51.64%, Al2O3 12.53%, Fe2O3 0.18%, CaO 11.4%, MgO1.36%, K2O 3.74%, Na2O 1.11%, ZnO 6.29%, BaO 8.6%.

[0089] The thermal expansion coefficient of the full-polished glaze is 6.5×10 -6 / ℃~6.8×10 -6 / ℃.

[0090] In one embodiment of the present application, the “preparing a ceramic tile body” in step S100 specifically includes:

[0091] Prepare green body powder according to the raw material formula of ceramic tile green body, wherein the whiteness of the green body powder is 20-30 degrees and the particle size of the powder is 0.3-0.6 mm;

[0092] Pressing the green body powder into a shape, and drying it at a drying temperature of 90 to 130° C. for 50 to 70 minutes to obtain a ceramic tile green body;

[0093] The thermal expansion coefficient of the ceramic tile body is 7.0×10 -6 / ℃~7.5×10 -6 / ℃.

[0094] Specifically, the green powder of the embodiment of the present application is composed of selected fine powder with less impurities, high purity and stable composition, with a whiteness of 20-30 degrees, a powder particle size of 0.3-0.6 mm, a ratio of 100%, and a thermal expansion coefficient of 7.0×10 -6 / ℃~7.5×10 -6 / ℃. The thermal expansion coefficient of the original ceramic tile body is about 7.8×10 -6 / °C, therefore, the embodiment of the present application reduces the thermal expansion coefficient of the ceramic body.

[0095] The embodiment of the present application adopts a high-precision press to ensure the forming performance of the green body and reduce the later firing deformation caused by uneven distribution of powder.

[0096] After the ceramic tile bodies are dried, two ceramic tile dust removal fans are used to remove dust from the ceramic tile bodies and a small amount of water is applied to cool the ceramic tile bodies. The amount of water sprayed is controlled at 70g + 1g / m2, and the ceramic tile body temperature is controlled between 65 and 85°C after water spraying.

[0097] The present application provides a basis for reducing the deformation of ceramic tile bodies by reducing the thermal expansion coefficient of the ceramic body.

[0098] In the embodiment of the present application, the step S100 of "applying a base glaze on the ceramic tile body to form a base glaze layer" specifically includes:

[0099] Applying a base glaze to the ceramic tile body by a bell-shaped glaze pouring method, with a glaze specific gravity of 1.72 to 1.80 and a glaze amount of 500 to 600 g / m2 to form a base glaze layer;

[0100] The thermal expansion coefficient of the base glaze is 6.8×10 -6 / ℃~7.2×10 -6 / ℃.

[0101] Specifically, after the ceramic tile body is cleaned, a layer of base glaze with low thermal expansion coefficient and good color development performance is applied for decoration to fill the capillary pores on the surface of the ceramic tile body. The thermal expansion coefficient of the applied base glaze is 7.0×10 -6 / ℃, which is between the ceramic tile body and the fully glazed one, and has good chemical stability, whiteness and color development ability, good flatness and other properties.

[0102] The base glaze applied in the embodiment of the present application can achieve a glaze whiteness of more than 60 degrees, a gloss within 5 degrees, a wear resistance level of more than level 4 2100 turns, and a flatness ≤0.3, so that the dark full-polished glaze can simultaneously achieve high color saturation, good flatness, wear resistance, high chemical stability and other properties.

[0103] In an embodiment of the present application, the functional ink includes: white ink, glossy ink and / or matte ink.

[0104] Specifically, the embodiment of the present application uses inkjet decorative printing to adjust the dark full-glaze pattern texture, and at the same time adds printing of multiple functional inks, such as white ink, glossy ink, matte ink, etc., by adjusting the whiteness difference and gloss difference between the pattern textures to bring about visual brightness and saturation differences, thereby achieving a pattern decoration effect with strong contrast and high clarity.

[0105] In the embodiment of the present application, step S300 specifically includes:

[0106] When drying the pattern decoration layer, the pattern decoration layer is dried using a plurality of open flame guns added to the glaze line drying kiln;

[0107] Use a rubber roller to roll the isolation glaze, the glaze specific gravity is 1.45-1.55, the glaze amount is 100-150 g / m2, to form an isolation glaze layer;

[0108] The isolation glaze is prepared using ethylene glycol as a solvent; the chemical composition of the isolation glaze, calculated by mass percentage, includes:

[0109] SiO2 45~55%, Al2O3 10~15%, CaO 10~15%, MgO 1~3%, K2O 2~4%, Na2O 2~4%, ZnO 5~10%, BaO 7~12%.

[0110] Specifically, because dark full-polished glaze is dark in color and requires a large amount of ink, if the full-polished glaze is directly poured, it is very easy to cause glaze avoidance defects, affecting the overall excellent rate. This is because the ink is oily and the full-polished glaze is water-based. If the ink is not dry when glazing, it is very easy to cause glaze avoidance defects. Therefore, the embodiment of the present application adds an open flame baking and application of high-transparency isolation glaze process after pattern decoration. Four open flame guns are added to the glaze line drying kiln to dry the ink, and then the isolation glaze is applied once using a rubber roller flower machine. Among them, the isolation glaze is prepared with ethylene glycol as a solvent instead of traditional rubber roller printing oil, making full use of the hydrophilic and lipophilic properties of ethylene glycol to improve the effects of ink oiliness on glaze avoidance, pinholes, pits, etc., thereby solving glazing defects and improving the overall excellent rate.

[0111] In the embodiment of the present application, step S400 specifically includes:

[0112] Applying full-polished glaze on the isolation glaze layer by a bell-shaped glaze pouring method, with a glaze specific gravity of 1.72 to 1.80 and a glaze amount of 400 to 500 grams per square meter to form a full-polished glaze layer;

[0113] The ceramic tiles are fired at a temperature of 1150-1220°C for 60-100 minutes, and then polished and waxed to obtain dark fully glazed ceramic tiles.

[0114] The thermal expansion coefficient of the full-glaze is 6.5×10 -6 / ℃~6.8×10 -6 / ℃.

[0115] In the embodiment of the present application, after the isolation glaze is applied by the rubber roller, a layer of high-hardness, high-transparency, and wear-resistant full-polished glaze is applied, and then the bricks are put into the kiln for firing. After the finished bricks are taken out of the kiln, they are polished, waxed, edged, and film-laminated. Specifically, after firing, high-precision polishing equipment is used and 4 polishing processes are adopted to gradually and evenly improve the gloss and transparency of the dark full-polished glaze to ensure that the glaze surface is as smooth as a mirror after polishing and waxing, thereby improving the clarity and transparency of the dark full-polished glaze.

[0116] Compared with traditional dark fully glazed ceramic tiles, the embodiments of the present application adopt a basic formula of ceramic tile body, base glaze and fully glazed ceramic tile with a lower thermal expansion coefficient. During the firing process, the expansion coefficients of the three layers of ceramic tile body, base glaze and fully glazed ceramic tile are evenly transitioned to avoid deformation caused by stress concentration due to drastic changes. The kiln flatness of the embodiments of the present application can achieve concave / convex ≤ 0.2 and batch deviation ≤ 0.4, which is much higher than the current industry control standards of concave / convex ≤ 0.4 and batch deviation ≤ 0.6 in the market. The flatness of the brick shape is greatly improved, which greatly reduces the risk of uneven yellow edges and yin and yang colors (i.e. color difference) in the glazing process caused by the flatness of the brick shape, improves the overall quality rate of the product, and reduces manufacturing costs.

[0117] The embodiment of the present application also reduces the amount of carbonate materials added by adjusting the basic formula of tile body, base glaze and full-polished glaze, and gives priority to using ternary aluminum raw materials instead of binary aluminum raw materials in glaze raw materials, thereby increasing its initial melting temperature and widening its melting range, improving its chemical stability, and achieving high hardness and high wear resistance at low aluminum content, reducing defects such as bubbles and pinholes generated by low-temperature materials during firing; thereby greatly reducing defects generated during the firing process, improving the overall quality rate, and reducing manufacturing costs.

[0118] The present invention also proposes adding an open flame baking step and the application of a high-transparency isolation glaze after pattern decoration. Four open flame guns are added to the glaze line's drying kiln to dry the ink, and then a rubber roller machine is used to apply the isolation glaze. The isolation glaze uses ethylene glycol as the solvent, replacing traditional rubber roller ink. This fully utilizes the hydrophilic and lipophilic properties of ethylene glycol to mitigate the effects of the ink's oiliness on glaze application, such as glaze avoidance, pinholes, and pitting. This eliminates glazing defects, improves the overall quality rate, and reduces manufacturing costs.

[0119] Therefore, this application achieves the following effects:

[0120] First, this application improves the overall quality rating of dark full-polished glaze and reduces manufacturing costs. Compared to the industry's current 92% overall quality rating for dark full-polished glaze, this application can increase the overall quality rating from the industry average of 92% to 97%, and reduce overall manufacturing costs by 20%. This not only meets the needs of high-end decoration, but can also penetrate the mid- and low-end markets, greatly enhancing market competitiveness.

[0121] Second, this application improves the smoothness and wear resistance of dark, fully polished glaze products, addressing existing issues such as deformation, color variation, and low wear resistance. By adjusting the basic formula of the blank and glaze, this application improves the smoothness of the brick, reduces color variation, and enhances the wear resistance of the product, significantly improving product quality and durability.

[0122] Third, this application improves the pattern clarity and color saturation of dark fully-glazed tiles, and solves the current industry problems of dark fully-glazed tiles prone to white fog and low transparency. It introduces raw materials for ternary aluminum glaze to replace traditional binary aluminum and alumina, improves the glaze hardness, wear resistance, and chemical stability, and can achieve high hardness and high wear resistance under low aluminum content. It increases the content of glass former SiO2 and uses high calcium and high barium to improve the glaze hardness, which can significantly reduce the aluminum content in the formula. At the same time, because the hardness and wear resistance problems are solved, the thickness of the glaze layer is reduced by 15%, thereby achieving high clarity and high transparency of dark fully-glazed tiles.

[0123] The present invention provides a preparation method of dark-colored fully-glazed ceramic tiles and dark-colored fully-glazed ceramic tiles. The preparation method of the dark-colored fully-glazed ceramic tiles comprises: preparing a ceramic tile body, applying a base glaze on the ceramic tile body to form a base glaze layer; inkjet decorative printing on the base glaze layer, and simultaneously printing functional ink to form a pattern decoration layer; drying the pattern decoration layer, and applying an isolation glaze to form an isolation glaze layer; applying a full-glaze on the isolation glaze layer to form a full-glaze layer, and then firing to obtain a dark-colored fully-glazed ceramic tile; wherein the thermal expansion coefficient of the base glaze layer is between the thermal expansion coefficient of the ceramic tile body and the thermal expansion coefficient of the full-glaze layer. The thermal expansion coefficient of the base glaze layer of the present application is between the thermal expansion coefficient of the ceramic tile body and the thermal expansion coefficient of the full-glaze layer, so that during the firing process, the thermal expansion coefficients of the three layers of the ceramic tile body, the base glaze, and the full-glaze are uniformly transitioned, thereby avoiding deformation caused by stress concentration due to drastic changes, and avoiding the problem of warping and unevenness of the dark-colored fully-glazed ceramic tiles.

[0124] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing dark fully glazed ceramic tiles, characterized in that: include: preparing a ceramic tile body, and applying a ground glaze on the ceramic tile body to form a ground glaze layer; Performing inkjet decorative printing on the base glaze layer and simultaneously printing functional ink to form a pattern decoration layer; drying the pattern decoration layer and applying an isolation glaze to form an isolation glaze layer; Applying full-polished glaze on the isolation glaze layer to form a full-polished glaze layer and then firing to obtain a dark full-polished glaze ceramic tile; Wherein, the thermal expansion coefficient of the bottom glaze layer is between the thermal expansion coefficient of the ceramic tile body and the thermal expansion coefficient of the full-polished glaze layer.

2. The method for preparing dark fully glazed ceramic tiles according to claim 1, characterized in that: The raw materials of the ceramic tile body include, by mass percentage: High alumina washed mud 20-30%, raw ore mud 10-15%, ball clay 3-9%, bentonite 5-10%, tonite powder 20-30%, malachite powder 5-10%, potassium sand and stone powder 3-6%, Xingning water abrasive 10-15%, magnesia 2-6%.

3. The method for preparing dark fully glazed ceramic tiles according to claim 1, characterized in that: The raw materials of the base glaze include, by mass percentage: Zinc oxide 1-2%, zirconium silicate 4-7%, potassium feldspar 20-30%, sodium feldspar 30-40%, kaolin 8-15%, calcined kaolin 5-10%, frit 10-20%, aluminum oxide 1-4%, dolomite 5-10%; wherein the thermal expansion coefficient of the frit is within a preset low expansion coefficient range; The chemical composition of the base glaze, calculated by mass percentage, comprises: SiO2 55~65%, Al2O3 18~22%, Fe2O3 0.1~0.2%, CaO 3~6%, MgO 1~3%, Na2O 1~4%, K2O 2~5%, ZnO 2~5%, BaO 0~2%.

4. The method for preparing dark fully polished glazed ceramic tiles according to claim 1, characterized in that: The raw materials of the full-polished glaze include, by mass percentage: Zinc oxide 4-6%, sodium fluorosilicate 3-5%, potassium feldspar 25-30%, sodium feldspar 10-15%, kaolin 6-10%, quartz 5-10%, high calcium and high barium frit 20-30%, calcite 8-15%, talc 6-10%; The chemical composition of the full-polished glaze is calculated by mass percentage and includes: SiO2 50~60%, Al2O3 10~15%, Fe2O3 0.1~0.2%, CaO 10~15%, MgO1~3%, K2O 2~4%, Na2O 1~3%, ZnO 5~10%, BaO 7~12%.

5. The method for preparing dark fully glazed ceramic tiles according to claim 1, characterized in that: Preparation of ceramic tile bodies, including: Prepare green body powder according to the raw material formula of ceramic tile green body, wherein the whiteness of the green body powder is 20-30 degrees and the particle size of the powder is 0.3-0.6 mm; Pressing the green body powder into a shape, and drying it at a drying temperature of 90 to 130° C. for 50 to 70 minutes to obtain a ceramic tile green body; The thermal expansion coefficient of the ceramic tile body is 7.0×10 -6 / ℃~7.5×10 -6 / ℃.

6. The method for preparing dark fully glazed ceramic tiles according to claim 1, characterized in that: Applying a base glaze on the ceramic tile body to form a base glaze layer comprises: Applying a base glaze to the ceramic tile body by a bell-shaped glaze pouring method, with a glaze specific gravity of 1.72 to 1.80 and a glaze amount of 500 to 600 g / m2 to form a base glaze layer; The thermal expansion coefficient of the base glaze is 6.8×10 -6 / ℃~7.2×10 -6 / ℃.

7. The method for preparing dark fully glazed ceramic tiles according to claim 1, characterized in that: The functional ink includes: white ink, glossy ink and / or matte ink.

8. The method for preparing dark fully glazed ceramic tiles according to claim 1, characterized in that: The pattern decoration layer is dried and an isolation glaze is applied to form an isolation glaze layer, comprising: When drying the pattern decoration layer, the pattern decoration layer is dried using a plurality of open flame guns added to the glaze line drying kiln; Use a rubber roller to roll the isolation glaze, the glaze specific gravity is 1.45-1.55, the glaze amount is 100-150 g / m2, to form an isolation glaze layer; The isolation glaze is prepared using ethylene glycol as a solvent; the chemical composition of the isolation glaze, calculated by mass percentage, includes: SiO2 45~55%, Al2O3 10~15%, CaO 10~15%, MgO 1~3%, K2O 2~4%, Na2O 2~4%, ZnO 5~10%, BaO 7~12%.

9. The method for preparing dark fully glazed ceramic tiles according to claim 1, characterized in that: Applying full-polished glaze on the isolation glaze layer to form a full-polished glaze layer and then firing to obtain a dark full-polished glaze tile, comprising: Applying full-polished glaze on the isolation glaze layer by a bell-shaped glaze pouring method, with a glaze specific gravity of 1.72 to 1.80 and a glaze amount of 400 to 500 grams per square meter to form a full-polished glaze layer; The ceramic tiles are fired at a temperature of 1150-1220°C for 60-100 minutes, and then polished and waxed to obtain dark fully glazed ceramic tiles. The thermal expansion coefficient of the full-glaze is 6.5×10 -6 / ℃~6.8×10 -6 / ℃.

10. A dark fully glazed tile, characterized in that: The dark fully glazed ceramic tile is prepared by the preparation method of the dark fully glazed ceramic tile according to any one of claims 1 to 9.

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