Lightweight high-strength domestic ceramic and preparation method thereof

Abstract

The invention belongs to the technical field of domestic ceramics, and particularly discloses a lightweight and high-strength domestic ceramic and a preparation method thereof. The domestic ceramic comprises a porous green body layer, a middle green body layer and a cover glaze layer, wherein the middle green body layer and the cover glaze layer sequentially cover the surface of the porous green body layer from inside to outside; the porous green body layer is prepared from the following raw material components in parts by weight: 30 to 35 parts of mechanically-piled mud, 40 to 45 parts of quartz, 10 to 15 parts of dolomite, 7 to 10 parts of calcium carbonate and 3 to 5 parts of zirconium silicate; and the pore-forming agent is a high-molecular polymer. The prepared domestic ceramic has high mechanical strength and smooth glaze appearance on the premise of reducing the weight of the product. Compared with bone china with the same thickness, the domestic ceramic has the advantages that the weight is reduced by 15-30%, and the impact strength is increased by more than 30%.

Description

Technical Field

[0001] The present invention belongs to the technical field of daily-use ceramics, and in particular relates to a light and high-strength daily-use ceramic and a preparation method thereof. Background Art

[0002] Daily ceramic tableware is an indispensable utensil in people's diet life, but ceramic materials also have their disadvantages compared with melamine or other polymer tableware on the market, such as low mechanical strength and heavy weight, which also affect its usage experience.

[0003] To address these shortcomings of household ceramics, researchers have been continuously exploring methods to strengthen and toughen ceramics, as well as reduce product weight. Currently, strengthening and toughening ceramics primarily involves adding a certain amount of inorganic fibers or whiskers to the green body formula, while reducing ceramic weight typically involves creating a porous structure to reduce product density and thus weight.

[0004] For example, patent publication CN111499368A discloses an ultra-light household ceramic. This ceramic uses chopped quartz and mullite fibers as a skeleton, with boron nitride and sepiolite as high-temperature binders. During sintering, adjacent short fibers are bonded together by heat-resistant silicon carbide, forming a high-porosity, lightweight, bird's nest-like structure with a certain strength. However, this preparation method is only suitable for low-temperature firing at 800-1000°C, making it difficult to ensure the mechanical strength of the product. Furthermore, the ceramic is unglazed.

[0005] Patent publication number CN104016703A discloses a method for preparing ultra-lightweight closed-cell ceramics. This method uses 5-60% oxide or nitride ceramic particles, 0.01-5% blowing agent, and water to create a stable foam. This foam is then sintered at 1500-2000°C to produce an ultra-lightweight closed-cell ceramic with a porosity of over 85%. However, the firing temperature of this ceramic product is too high to be suitable for household ceramics (generally not exceeding 1400°C).

[0006] At the same time, household ceramics also have very high requirements for surface smoothness. Porous ceramic bodies prepared using conventional pore-forming methods inevitably contain open pores. If glazed directly, the fired product will inevitably have an uneven glaze surface and even defects such as pinholes and melt holes. In addition, the typical thickness of household ceramics is generally 5-6mm, and the thinnest ones are even 2-3mm. It is difficult to ensure the strength of porous ceramics made with such a thin thickness.

[0007] Therefore, there is an urgent need to develop a new daily-use ceramic that can simultaneously have high mechanical strength and good glaze quality while reducing product weight. Summary of the Invention

[0008] The present invention aims to address at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a lightweight, high-strength household ceramic and a method for preparing the same. Compared to conventional household ceramics of the same thickness (such as bone china), the present invention not only reduces weight by 15-30%, but also increases impact strength by over 30%, while maintaining good glaze quality.

[0009] In order to solve the above technical problems, the first aspect of the present invention provides a daily-use ceramic, including a porous green body layer, an intermediate green body layer and a surface glaze layer, wherein the intermediate green body layer and the surface glaze layer are sequentially covered on the surface of the porous green body layer from the inside to the outside; the raw material components of the porous green body layer include a basic green body and a pore-forming agent, and the basic green body includes, by weight: 30-35 parts of machine-made mud, 40-45 parts of quartz, 10-15 parts of dolomite, 7-10 parts of calcium carbonate, and 3-5 parts of zirconium silicate; the pore-forming agent is a high molecular polymer.

[0010] Specifically, the present invention uses a high molecular polymer as a pore-forming agent. The high molecular polymer will decompose at a lower temperature to form large pores. The pore diameter of these large pores becomes smaller during the high-temperature firing process, so that the green body layer forms a porous structure, thereby reducing the weight of daily-use ceramics. However, the addition of the high molecular polymer will not only have a significant impact on the plasticity of the green body, but also the formed pores are easily filled during the firing process, and may have a negative impact on the strength and glaze quality of the product. In response to this, the basic green body of the present invention uses machine-stacked mud as a clay raw material, which is used to improve the plasticity and strength of the green body; and uses calcium magnesium alkaline earth metal minerals (dolomite and calcium carbonate) as fluxes, and adds a certain amount of zirconium silicate to reduce the high-temperature fluidity of the green body, thereby effectively preventing the pores from being filled, ensuring the formation of a porous structure, and reducing the impact on the glaze quality. In addition, quartz and zirconium silicate are beneficial to enhancing the strength of the porous skeleton structure.

[0011] In some embodiments of the present invention, the pore-forming agent is selected from at least one of polypropylene and polycarbonate.

[0012] Specifically, these high molecular polymers can decompose at relatively low temperatures (below 400°C) to form larger pores, and the pores become smaller during the subsequent high-temperature sintering process. By adjusting the components of the basic blank, it is beneficial to form a porous structure with appropriate pore size.

[0013] In some embodiments of the present invention, the particle size of the pore-forming agent is 40-60 mesh.

[0014] Specifically, the selection of a pore-forming agent with this particle size can not only better match the base blank and prevent agglomeration during the mixing process; it can also obtain a suitable pore size, preventing the green body strength after molding from being too low due to the particles being too large; and preventing the pores from being completely filled during the high-temperature firing process due to the particles being too small.

[0015] In some embodiments of the present invention, the mass ratio of the base blank to the pore-forming agent is (96-98): (2-4). By controlling the amount of the pore-forming agent added, the weight of the product can be reduced while ensuring its mechanical strength.

[0016] In some embodiments of the present invention, the raw material components of the intermediate green body layer include, by weight: 30-35 parts of machine pile mud, 35-45 parts of quartz, 15-25 parts of potassium feldspar, 3-5 parts of alumina, and 2-5 parts of dolomite.

[0017] Specifically, the raw material composition of the intermediate green body layer of the present invention is similar to that of the porous green body layer. Furthermore, potassium feldspar and dolomite are used as fluxes, and a certain amount of alumina is added for reinforcement to reduce the high-temperature viscosity of the intermediate green body layer, making it easier to spread and fill the surface of the porous green body layer, thereby forming a smooth, dense intermediate layer. This not only helps reduce glaze defects but also improves the mechanical strength of the product.

[0018] In some embodiments of the present invention, the Al2O3 content in the machine-pile mud is 37-40wt%, and the plasticity index is ≥17. Machine-pile mud is a mud material obtained by machine-pile processing of high-alumina washed mud. Compared with traditional clay raw materials (such as kaolin), this mud material has a higher aluminum content and plasticity.

[0019] In some embodiments of the present invention, the plasticity index of the machine pile mud is 17-19.

[0020] In some embodiments of the present invention, the chemical composition of the glaze layer includes, by weight percentage: 50-55% SiO2, 9-11% Al2O3, 4-6% K2O, 4-6% Na2O, 0-0.1% Fe2O3, 0-0.05% TiO2, 7-9% CaO, 1-2% MgO, 7-9% ZnO, 3-4% B2O3, 2-4% SrO, and a loss on ignition of 1.5-2.5%.

[0021] In some embodiments of the present invention, the glaze used to prepare the glaze layer is frit glaze.

[0022] Specifically, by adjusting the chemical composition of the surface glaze layer, it has a higher initial melting temperature, preventing the premature closure of pores and leaving defects such as pinholes and melt holes on the glaze surface; at the same time, it has good body-glaze adaptability with the intermediate body layer, thereby improving the mechanical strength of the product.

[0023] In some embodiments of the present invention, the thickness ratio of the porous green body layer, the intermediate green body layer and the glaze layer is (70-80): (10-15): (10-15).

[0024] A second aspect of the present invention provides a method for preparing the above-mentioned daily-use ceramics, comprising the following steps:

[0025] (1) wet grinding and spray granulation of a base blank to obtain a base blank powder; then mixing the base blank powder with a pore-forming agent and forming the mixture to obtain a porous blank layer;

[0026] (2) wet-grinding the raw materials for preparing the intermediate body layer to obtain a slurry; then immersing the porous body layer in the slurry, and drying the slurry to form an intermediate body layer, thereby obtaining a green body;

[0027] (3) biscuit-firing the green body to obtain a biscuit-fired body;

[0028] (4) After the unglazed blank is ground and polished, a glaze is sprayed to form a glaze layer, and glaze firing is performed to obtain the daily-use ceramic.

[0029] In some embodiments of the present invention, in step (1), the particle gradation of the basic green body powder is as follows: the mass proportion of particles with a size of 20 mesh and above is less than 1%, the mass proportion of particles with a size of 20-40 mesh is 35-50%, the mass proportion of particles with a size of 40-80 mesh is 45-60%, and the mass proportion of particles with a size of less than 80 mesh is less than 5%.

[0030] In some embodiments of the present invention, in step (1), the molding method is isostatic pressing.

[0031] Specifically, because a certain amount of lightweight pore-forming agent is added to the porous green body layer, the agent tends to float or aggregate in the slurry, making traditional rolling or high-pressure grouting impossible. Therefore, the present invention employs isostatic pressing and controls a specific particle size distribution to ensure the strength of the porous green body layer after forming.

[0032] In some embodiments of the present invention, in step (2), the slurry has a concentration of 37-40 degrees Baume. By controlling the slurry concentration, an intermediate green body layer of suitable thickness can be obtained; if the intermediate green body layer is too thick, it will not be conducive to the discharge of gas from the porous green body layer, while if it is too thin, it will not be able to completely cover the lightweight porous layer.

[0033] In some embodiments of the present invention, in step (1) and step (2), the wet grinding further includes an iron removal step.

[0034] In some embodiments of the present invention, in step (3), the maximum temperature of the biscuit firing is 1250-1280° C., and the firing period of the biscuit firing is 18-20 hours.

[0035] Specifically, the high-temperature slow-firing bisque firing system is beneficial to the full decomposition of the polymer pore-forming agent into pores, preventing the incomplete decomposition of the pore-forming agent during the glaze firing process from affecting the glaze quality; on the other hand, it is beneficial to the filling of the porous body layer by the intermediate body layer, forming a closed-pore porous structure and improving the glaze quality.

[0036] In some embodiments of the present invention, in step (4), the maximum temperature of the glaze firing is 1130-1160° C., and the firing cycle of the glaze firing is 7-8 hours.

[0037] Specifically, the firing system that combines high-temperature bisque firing with low-temperature glaze firing can effectively reduce the occurrence of defects such as glaze pinholes and melt holes, and improve the quality of the glaze.

[0038] In some embodiments of the present invention, in step (4), the grinding and polishing is performed by wet grinding and polishing using a spiral vibration grinder to ensure that the bisque-fired body is smooth and flat.

[0039] Compared with the prior art, the above technical solution of the present invention has at least the following technical effects or advantages:

[0040] (1) The daily-use ceramics of the present invention include a porous body layer, an intermediate body layer, and a surface glaze layer. The porous body layer uses a high molecular weight polymer as a pore-forming agent. The high molecular weight polymer decomposes at low temperatures to form large pores. The pore diameter decreases during high-temperature firing, forming a porous structure to reduce the weight of the product. At the same time, the porous body layer uses a specific composition of machine-pile mud, calcium magnesium alkaline earth metal minerals, zirconium silicate, and quartz as the basic material, ensuring the formation of the porous structure, reducing the impact of pores on the glaze quality, and improving the mechanical strength of the product.

[0041] (2) By optimizing and rationally compounding the raw material components of each layer of the daily-use ceramic, controlling the particle size and particle size distribution, and adopting a high-temperature bisque firing and low-temperature glaze firing system, the daily-use ceramic produced by the present invention can simultaneously achieve high mechanical strength and good glaze quality while reducing the product weight. Compared with traditional daily-use bone china of the same thickness, this daily-use ceramic not only reduces the weight by 15-30%, but also increases the impact strength by more than 30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the cross-sectional structure of the daily-use ceramic of the present invention. DETAILED DESCRIPTION

[0043] The present invention is described in detail below with reference to the examples to facilitate understanding of the present invention by those skilled in the art. It is necessary to point out that the examples are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above-mentioned invention should still fall within the scope of protection of the present invention. At the same time, the raw materials mentioned below that are not described in detail are all commercially available products; the process steps or preparation methods that are not mentioned in detail are all process steps or preparation methods known to those skilled in the art.

[0044] like Figure 1 As shown, the daily-use ceramics of the present invention include a porous body layer 100, an intermediate body layer 200 and a surface glaze layer 300, wherein: the intermediate body layer 200 and the surface glaze layer 300 are sequentially covered on the surface of the porous body layer 100 from the inside to the outside, that is, the intermediate body layer 200 completely covers the outer surface of the porous body 100, and the surface glaze layer 300 completely covers the outer surface of the intermediate body layer 200.

[0045] Example 1

[0046] A daily-use ceramic (bowl) comprises a porous body layer, an intermediate body layer and a glaze layer. The thickness ratio of the porous body layer, the intermediate body layer and the glaze layer is 75:15:10. The total thickness of the product is 4 mm and the size is 4.5 inches.

[0047] The raw material components of the porous green body layer include a basic green body and a pore-forming agent in a mass ratio of 98:2, and the pore-forming agent is polypropylene with a particle size of 50 meshes.

[0048] The basic blank comprises, by weight, 30 parts of machine pile mud, 45 parts of quartz, 10 parts of dolomite, 10 parts of calcium carbonate, and 5 parts of zirconium silicate.

[0049] The raw material components of the intermediate green body layer include, by weight, 30 parts of machine pile mud, 45 parts of quartz, 17 parts of potassium feldspar, 3 parts of alumina, and 5 parts of dolomite.

[0050] The Al2O3 content in the machine pile mud is 38wt% and the plasticity index is 17.

[0051] The chemical composition of the glaze layer includes, by weight percentage: 55% SiO2, 9% Al2O3, 6% K2O, 4% Na2O, 0.05% Fe2O3, 0.05% TiO2, 8% CaO, 1% MgO, 8% ZnO, 4% B2O3, 3% SrO, and a loss on ignition of 1.9%.

[0052] The method for preparing the above-mentioned daily-use ceramic bowl comprises the following steps:

[0053] (1) The base blank is ground, iron is removed by screening, and spray granulation is performed to obtain a base blank powder; the base blank powder is then mixed with a pore-forming agent and isostatically pressed to obtain a porous blank layer; wherein: the particle size distribution of the base blank powder is as follows: the mass proportion of particles with a size of more than 20 mesh is 0.5%, the mass proportion of particles with a size of 20-40 mesh is 45%, the mass proportion of particles with a size of 40-60 mesh is 50%, and the mass proportion of particles with a size of less than 60-80 mesh is 4.5%.

[0054] (2) wet-grinding the raw materials for preparing the intermediate green body layer, sieving out iron, and preparing a slurry (with a concentration of 39 degrees Baume); then immersing the porous green body layer prepared in step (1) in the slurry, and drying it to form an intermediate green body layer, thereby preparing a green body;

[0055] (3) biscuit-firing the green body obtained in step (2) to obtain a biscuit-fired body; wherein the maximum biscuit-firing temperature is 1260° C. and the firing period is 19 hours;

[0056] (4) The bisque-fired blank obtained in step (3) is wet-polished using a spiral vibrating grinder. After drying, it is sprayed with glaze to form a glaze layer, and then glaze-fired. The maximum glaze-firing temperature is 1150° C., and the glaze-firing cycle is 7 hours. Thus, the daily-use ceramic (bowl) of this embodiment is obtained.

[0057] Example 2

[0058] A daily-use ceramic (bowl) comprises a porous body layer, an intermediate body layer and a glaze layer. The thickness ratio of the porous body layer, the intermediate body layer and the glaze layer is 70:15:15. The total thickness of the product is 4 mm and the size is 4.5 inches.

[0059] The raw material components of the porous green body layer include a base green body and a pore-forming agent in a mass ratio of 96:4, and the pore-forming agent is polycarbonate with a particle size of 40 meshes.

[0060] The basic blank comprises, by weight, 35 parts of machine pile mud, 40 parts of quartz, 15 parts of dolomite, 7 parts of calcium carbonate and 3 parts of zirconium silicate.

[0061] The raw material components of the intermediate green body layer include, by weight, 35 parts of machine pile mud, 40 parts of quartz, 20 parts of potassium feldspar, 3 parts of alumina, and 2 parts of dolomite.

[0062] The Al2O3 content in the machine pile mud is 39wt% and the plasticity index is 18.

[0063] The chemical composition of the glaze layer includes, by weight percentage: 50% SiO2, 11% Al2O3, 6% K2O, 5% Na2O, 0.1% Fe2O3, 0.02% TiO2, 7% CaO, 2% MgO, 9% ZnO, 4% B2O3, 4% SrO, and a loss on ignition of 1.88%.

[0064] The method for preparing the above-mentioned daily-use ceramic bowl comprises the following steps:

[0065] (1) The base blank is ground, iron is removed by screening, and spray granulation is performed to obtain a base blank powder; the base blank powder is then mixed with a pore-forming agent and isostatically pressed to obtain a porous blank layer; wherein: the particle size distribution of the base blank powder is as follows: the mass proportion of particles with a size of 20 mesh or more is 0.3%, the mass proportion of particles with a size of 20-40 mesh is 45%, the mass proportion of particles with a size of 40-80 mesh is 52%, and the mass proportion of particles with a size of less than 80 mesh is less than 2.7%.

[0066] (2) wet-grinding the raw materials for preparing the intermediate green body layer, sieving out iron, and preparing a slurry (with a concentration of 38 degrees Baume); then immersing the porous green body layer prepared in step (1) in the slurry, and drying it to form an intermediate green body layer, thereby preparing a green body;

[0067] (3) biscuit-firing the green body obtained in step (2) to obtain a biscuit-fired body; wherein the maximum biscuit-firing temperature is 1270° C. and the firing period is 18 hours;

[0068] (4) The bisque-fired blank obtained in step (3) is wet-polished using a spiral vibrating grinder. After drying, it is sprayed with glaze to form a glaze layer, and then glaze-fired. The maximum glaze-firing temperature is 1160° C., and the glaze-firing cycle is 7 hours. Thus, the daily-use ceramic (bowl) of this embodiment is obtained.

[0069] Example 3

[0070] A daily-use ceramic (bowl) comprises a porous body layer, an intermediate body layer and a glaze layer. The thickness ratio of the porous body layer, the intermediate body layer and the glaze layer is 75:15:10. The total thickness of the product is 4 mm and the size is 4.5 inches.

[0071] The raw material components of the porous green body layer include a basic green body and a pore-forming agent in a mass ratio of 97:3, and the pore-forming agent is polypropylene with a particle size of 60 meshes.

[0072] The basic blank comprises, by weight, 32 parts of machine pile mud, 43 parts of quartz, 13 parts of dolomite, 8 parts of calcium carbonate and 4 parts of zirconium silicate.

[0073] The raw material components of the intermediate green body layer include, by weight, 33 parts of machine pile mud, 40 parts of quartz, 20 parts of potassium feldspar, 4 parts of alumina, and 3 parts of dolomite.

[0074] The Al2O3 content in the machine pile mud is 40wt% and the plasticity index is 19.

[0075] The chemical composition of the glaze layer includes, by weight percentage: 54% SiO2, 11% Al2O3, 5% K2O, 5% Na2O, 0.05% Fe2O3, 0.05% TiO2, 8% CaO, 1% MgO, 8% ZnO, 3% B2O3, 3% SrO, and a loss on ignition of 1.9%.

[0076] The method for preparing the above-mentioned daily-use ceramic bowl comprises the following steps:

[0077] (1) The base blank is ground, iron is removed by screening, and spray granulation is performed to obtain a base blank powder; the base blank powder is then mixed with a pore-forming agent and isostatically pressed to obtain a porous blank layer; wherein: the particle size distribution of the base blank powder is as follows: the mass proportion of particles with a size of more than 20 mesh is 0.5%, the mass proportion of particles with a size of 20-40 mesh is 50%, the mass proportion of particles with a size of 40-80 mesh is 46%, and the mass proportion of particles with a size of less than 80 mesh is 3.5%.

[0078] (2) wet-grinding the raw materials for preparing the intermediate green body layer, sieving out iron, and preparing a slurry (with a concentration of 37 degrees Baume); then immersing the porous green body layer prepared in step (1) in the slurry, and drying it to form an intermediate green body layer, thereby preparing a green body;

[0079] (3) biscuit-firing the green body obtained in step (2) to obtain a biscuit-fired body; wherein the maximum biscuit-firing temperature is 1250° C. and the firing period is 19 hours;

[0080] (4) The bisque-fired blank obtained in step (3) is wet-polished using a spiral vibrating grinder. After drying, it is sprayed with glaze to form a glaze layer, and glaze firing is performed. The maximum glaze firing temperature is 1130° C., and the glaze firing cycle is 8 hours, thereby obtaining the daily-use ceramic (bowl) of this embodiment.

[0081] Comparative Example 1

[0082] The difference between Comparative Example 1 and Example 1 is that the raw material components of the basic blank are different. Comparative Example 1 uses an equal amount of kaolin (alumina content of 30wt%, plasticity index of 12) to replace the machine pile mud in Example 1.

[0083] Comparative Example 2

[0084] The difference between Comparative Example 2 and Example 1 is that the raw material components of the basic blank are different. The raw material components of the basic blank of Comparative Example 2 include, by weight, 30 parts of machine pile mud, 45 parts of quartz, 20 parts of potassium feldspar, and 5 parts of zirconium silicate.

[0085] Comparative Example 3

[0086] The difference between Comparative Example 3 and Example 1 is that the pore-forming agent is different. In Comparative Example 3, silicon carbide with the same particle size and amount is used to replace the polypropylene in Example 1.

[0087] Comparative Example 4

[0088] The difference between Comparative Example 4 and Example 1 is that the raw material components of the intermediate body are different. Comparative Example 4 uses an equal amount of albite to replace the dolomite in Example 1.

[0089] Comparative Example 5

[0090] The difference between Comparative Example 5 and Example 1 is that the particle gradation of the basic green body powder is different. The particle gradation of the basic green body powder in Comparative Example 5 is: the mass proportion of particles with a size of more than 20 mesh is 0.5%, the mass proportion of particles with a size of 20-40 mesh is 80%, the mass proportion of particles with a size of 40-60 mesh is 15%, and the mass proportion of particles with a size of less than 60-80 mesh is 4.5%.

[0091] Comparative Example 6

[0092] The difference between Comparative Example 6 and Example 1 is that the firing process is different. Comparative Example 6 adopts a one-time firing process without biscuit firing, and the maximum firing temperature is 1250° C. and the firing cycle is 18 hours.

[0093] Comparative Example 7

[0094] The daily-use ceramic of Comparative Example 7 is traditional daily-use bone porcelain, comprising a body layer and a glaze layer. The thickness ratio of the body layer to the glaze layer is 90:10, the total thickness of the product is 4 mm, and the size is 4.5 inches.

[0095] The raw material components of the green body layer include, by weight, 35 parts of kaolin, 24 parts of quartz, 36 parts of bone char, and 5 parts of bentonite.

[0096] The chemical composition of the glaze layer includes, by weight percentage: 55% SiO2, 9% Al2O3, 6% K2O, 4% Na2O, 0.05% Fe2O3, 0.05% TiO2, 8% CaO, 1% MgO, 8% ZnO, 4% B2O3, 3% SrO, and a loss on ignition of 1.9%.

[0097] The method for preparing the above-mentioned daily-use ceramic bowl comprises the following steps:

[0098] (1) The raw materials of the green body layer are ground, iron is removed by screening, and spray granulation is performed to obtain a basic green body powder, which is then isostatically pressed to obtain the green body layer.

[0099] (2) biscuit-firing the green body layer obtained in step (1) to obtain a biscuit green body; wherein the maximum biscuit-firing temperature is 1260° C. and the firing period is 19 hours;

[0100] (3) The bisque-fired blank obtained in step (2) is wet-polished using a spiral vibrating grinder. After drying, it is sprayed with glaze to form a glaze layer, and then glaze-fired. The maximum glaze-firing temperature is 1150° C., and the glaze-firing cycle is 7 hours. Thus, the daily-use ceramic (bowl) of this comparative example is obtained.

[0101] Performance Testing

[0102] The household ceramic samples (bowls) prepared in Examples 1-3 and Comparative Examples 1-7 were subjected to weight and mechanical property tests. The formation of the porous green body layer was recorded, and the glaze quality of the products was observed. The impact strength was tested according to the T / CCIA0008-2021 standard, and the test results are shown in Table 1.

[0103] Table 1:

[0104]

[0105]

[0106] As shown in Table 1, the daily-use ceramics prepared in Examples 1-3 are not only 15-30% lighter than the traditional daily-use bone china of the same size (4.5 inches) and thickness (4 mm) as in Comparative Example 7, but also have an impact strength increased by more than 30% and a good glaze quality.

[0107] Compared with Example 1, Comparative Examples 1 and 5 respectively use conventional clay and particle grading in the base blank, which results in that the porous green body layer cannot be formed smoothly.

[0108] Compared with Example 1, in Comparative Examples 2 and 6, the pores generated by the decomposition of the pore-forming agent were completely filled due to the use of traditional potassium feldspar as a flux and a single-firing process in the base blank, respectively. Therefore, the total weight of the product was not reduced.

[0109] Compared with Example 1, Comparative Example 3 uses high-temperature dispersed pore-forming agent silicon carbide instead of polypropylene. Although it also has a good pore-forming effect, it causes a series of glaze problems, such as blackening, pinholes and melt holes, and the impact strength is also reduced.

[0110] Compared with Example 1, in Comparative Example 4, since the intermediate body layer uses low-temperature flux albite instead of dolomite in Example 1, the high-temperature viscosity is too low, and the gas generated in the body layer overflows into the glaze layer, resulting in a large number of pinholes on the glaze surface.

[0111] For those skilled in the art to which the present invention belongs, a number of simple deductions or substitutions can be made without departing from the concept of the present invention, without having to resort to creative work. Therefore, based on the disclosure of the present invention, simple improvements made by those skilled in the art to the present invention should be within the scope of protection of the present invention. The above embodiments are preferred embodiments of the present invention, and all processes similar to the present invention and equivalent changes made should fall within the scope of protection of the present invention.

Claims

1. A daily-use ceramic, characterized in that: The invention comprises a porous green body layer, an intermediate green body layer and a surface glaze layer, wherein the intermediate green body layer and the surface glaze layer sequentially cover the surface of the porous green body layer from the inside to the outside; the raw material components of the porous green body layer include a basic green body and a pore-forming agent, wherein the basic green body comprises, by weight, 30-35 parts of machine pile mud, 40-45 parts of quartz, 10-15 parts of dolomite, 7-10 parts of calcium carbonate and 3-5 parts of zirconium silicate; the pore-forming agent is a high molecular polymer.

2. The daily-use ceramic according to claim 1, characterized in that: The pore-forming agent is selected from at least one of polypropylene and polycarbonate; and / or the particle size of the pore-forming agent is 40-60 mesh.

3. The daily-use ceramic according to claim 1, characterized in that: The mass ratio of the basic blank to the pore-forming agent is (96-98): (2-4).

4. The daily-use ceramic according to claim 1, characterized in that: The raw material components of the intermediate body layer include, by weight, 30-35 parts of machine pile mud, 35-45 parts of quartz, 15-25 parts of potassium feldspar, 3-5 parts of alumina, and 2-5 parts of dolomite.

5. The daily-use ceramic according to claim 1 or 4, characterized in that: The Al2O3 content in the machine pile mud is 37-40wt%, and the plasticity index is ≥17.

6. The daily-use ceramic according to claim 1, characterized in that: The chemical composition of the glaze layer includes, by weight percentage, 50-55% SiO2, 9-11% Al2O3, 4-6% K2O, 4-6% Na2O, 0-0.1% Fe2O3, 0-0.05% TiO2, 7-9% CaO, 1-2% MgO, 7-9% ZnO, 3-4% B2O3, 2-4% SrO, and a loss on ignition of 1.5-2.5%.

7. The daily-use ceramic according to claim 1, characterized in that: The thickness ratio of the porous green body layer, the intermediate green body layer and the surface glaze layer is (70-80): (10-15): (10-15).

8. A method for preparing the daily-use ceramic according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) wet grinding and spray granulation of a base blank to obtain a base blank powder; then mixing the base blank powder with a pore-forming agent and forming the mixture to obtain a porous blank layer; (2) wet-grinding the raw materials for preparing the intermediate body layer to obtain a slurry; then immersing the porous body layer in the slurry, and drying the slurry to form an intermediate body layer, thereby obtaining a green body; (3) biscuit-firing the green body to obtain a biscuit-fired body; (4) After the unglazed body is ground and polished, a glaze is sprayed to form a glaze layer, and glaze firing is performed to obtain the daily-use ceramic.

9. The method for preparing daily-use ceramics according to claim 8, characterized in that: In step (1), the particle size distribution of the basic green body powder is as follows: the mass proportion of particles with a size of 20 mesh and above is less than 1%, the mass proportion of particles with a size of 20-40 mesh is 35-50%, the mass proportion of particles with a size of 40-80 mesh is 45-60%, and the mass proportion of particles with a size of less than 80 mesh is less than 5%.

10. The method for preparing daily-use ceramics according to claim 8, characterized in that: In step (2), the concentration of the slurry is 37-40 degrees Baume; And / or, in step (3), the maximum temperature of the biscuit firing is 1250-1280°C, and the biscuit firing period is 18-20 hours; And / or, in step (4), the maximum temperature of the glaze firing is 1130-1160° C., and the firing cycle of the glaze firing is 7-8 hours.

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