Easily demoulded pottery jar preparation process

Abstract

The invention relates to the field of pottery jars, aims to solve the problem of low production efficiency caused by the fact that a wet blank needs to be reserved for a long time in a gypsum model in the existing pottery jar preparation process, and provides a pottery jar preparation process which comprises the following steps: S100, main materials and water are prepared into pug, the main materials comprise raw materials and clinker, and the clinker accounts for 6-10 wt% of the main materials; s200, molding the pug through a gypsum model to obtain a wet blank; s300, after the wet blank is dried through a primary drying process, demolding is conducted, and a prefabricated product is obtained; and S400, after the prefabricated product is subjected to a secondary drying process and a sintering process, the pottery jar is obtained. By improving the pug ratio, additionally drying the plaster model, improving the plaster-water ratio of the plaster model and improving the structure and the drying process of the wet blank, the retention time of the wet blank in the plaster model is greatly shortened on the premise of ensuring the form stability of the wet blank during demolding, the energy consumption is reduced, and the productivity is improved.

Description

Technical Field

[0001] The present invention relates to the field of pottery jars, and more particularly to a preparation process for a pottery jar with easy demolding. Background Art

[0002] A pottery jar is a traditional container, usually made of clay, and goes through processes such as forming, drying, and firing. The preparation of a pottery jar generally requires processes such as material selection, embryo making, trimming and decoration, drying, and firing. Among them, the embryo making process can use a plaster model to form the clay material. However, for the wet embryo to be successfully demolded, its water content needs to be relatively low. If the initial water content of the clay material is too low, it is not conducive to its rolling forming. Therefore, when the initial water content of the clay material is relatively high, the wet embryo needs to stay in the plaster model for a longer time, resulting in lower production efficiency. Summary of the Invention

[0003] The purpose of the present invention is to provide a preparation process for a pottery jar with easy demolding, so as to solve the problem of low production efficiency caused by the need for the wet embryo to stay in the plaster model for a long time during the preparation of existing pottery jars.

[0004] The embodiments of the present invention are achieved through the following technical solutions:

[0005] A preparation process for a pottery jar with easy demolding includes the following steps:

[0006] S100. Prepare a clay material by mixing a main material and water. The main material includes a raw material and a clinker, and the clinker accounts for 6wt%-10wt% of the main material;

[0007] S200. The clay material is formed by a plaster model to obtain a wet embryo;

[0008] S300. After the wet embryo is dried by a primary drying process, it is demolded to obtain a preform;

[0009] S400. After the preform goes through a secondary drying process and a sintering process, a pottery jar is obtained.

[0010] In the prior art, the embryo making process uses a plaster model to form the clay material. However, for the wet embryo to be successfully demolded, its water content generally needs to be about 15%. If the initial water content of the clay material is too low, it is not conducive to its rolling forming. Therefore, the initial water content of the clay material is generally 20%-22%, and the water content basically needs to lose about 6%. The wet embryo needs to stay in the plaster model for a long time, resulting in lower production efficiency. Usually, it takes 2-3 days to demold the plaster model. When the winter temperature is relatively low, the time will be appropriately extended. The entire process is difficult to accurately control, and the quality uniformity of the products is relatively low. Therefore, the applicant hopes to make the demolding of the wet embryo controllable within 24 hours through technical improvement, shorten the residence time of the wet blank in the plaster model, reduce the occupation of the site, improve production capacity, and reduce energy consumption.

[0011] While ensuring the air permeability during the firing process of the mud embryo, the present invention appropriately increases the proportion of clinker. The clinker is preferably in the form of particulate matter, without powder, and does not reduce the plasticity of the mud. In addition, during rolling forming, the plastic roller of the rolling press can be replaced with a composite nylon roller. Since the hardness of the composite nylon is greatly improved, the wear resistance is improved, and the service life of the nylon roller is extended by 2-3 times.

[0012] Preferably, the S300 includes: drying the gypsum model again after demolding until the water content is 5wt%-8wt%.

[0013] The prior art is to directly perform the rolling of the next batch of wet embryos after demolding the wet embryos. However, the gypsum model has a certain water absorption function. During the process from the forming to the demolding of the previous batch of wet embryos, the gypsum model has absorbed a certain amount of water, and thus its water absorption function will be damaged to a certain extent. Furthermore, during the process from the forming to the demolding of the next batch of wet embryos, if the same process conditions are adopted, the final products will have performance differences or even demolding failures. And to meet the demolding conditions, the retention time of the wet embryos in the gypsum model will be further increased. Therefore, in order to reduce the retention time of the wet embryos in the gypsum model and improve the process controllability, the present invention adds a drying process for the gypsum model. Through experiments, it is obtained that when the gypsum model is dried until the water content is not higher than 8%, it can maintain a good water absorption function without consuming too much drying time. In addition, for the bottom mold at the bottom of the gypsum model, a low-pressure fast drainage process can be used, and compressed air is used to drain water at any time to avoid insufficient drying time of the bottom mold and failure to meet the water content requirements.

[0014] Preferably, the heat energy sources for drying the gypsum model include: waste heat from the kiln and a hot air device, and the hot air device is arranged inside the wet embryo.

[0015] Utilizing the preheating of the kiln can reduce energy consumption.

[0016] Preferably, the temperature of the waste heat from the kiln is 400°C - 500°C, the temperature of the hot air generated by the hot air device is 100°C - 150°C higher than the waste heat from the kiln, and the drying time is 18h - 22h.

[0017] Although directly using the waste heat from the kiln can also achieve the drying of the gypsum model, the drying time is relatively long, which is contrary to the aforementioned improvement of production capacity. Therefore, the present invention adds a hot air device inside the model and the temperature of the hot air device is higher than that of the kiln. By controlling the temperature difference between the hot air and the waste heat from the kiln, the drying time of the gypsum model is reduced as much as possible on the premise of ensuring the morphological and structural stability of the gypsum model.

[0018] Preferably, the paste-water ratio of the gypsum model is 100:(40 - 60).

[0019] The process of making a gypsum model is a chemical reaction process between hemihydrate gypsum and water. Adjusting the plaster-water ratio is very important. If the water content is relatively high, the strength of the gypsum model will decrease. If the water content is relatively low, the porosity of the gypsum model will be insufficient, affecting the siphon capillary negative pressure water absorption function of the gypsum model, and the moisture content of the wet blank cannot reach the required level in a short time. After many experiments, the applicant reduced the plaster-water ratio as much as possible while ensuring the porosity, strength, and drying stability of the gypsum. Since under the preparation process of the present invention, the gypsum model will undergo repeated water absorption and drying processes, and thus the gypsum model will continuously experience a certain degree of linear shrinkage and slight expansion. Therefore, during the process of adjusting the ratio, the structural stability and recoverability of the gypsum model under the preparation process of the present invention need to be ensured.

[0020] Preferably, the particle size of the main material is 48μm - 58μm.

[0021] The main material can be ground by a ball mill. By reducing the particle size in the present invention, the specific surface area of the main material particles is increased, the plasticity of the mud is improved, the moisture content of the mud in the initial stage can be reduced to a certain extent, and further the retention time of the wet blank in the gypsum model can be shortened. Since the hardness of the mud is increased, the cast iron of the original roller axis often breaks. Therefore, the material of the inner axis of the plastic roller of the rolling press can be improved to 40 chromium special steel, which has high toughness and can ensure the service life of the equipment even when the hardness of the mud in the present invention is increased.

[0022] Preferably, the mass ratio of the main material to water in the S100 is 100:(15 - 18).

[0023] Since the particle size of the main material is reduced, the ratio of the main material to water can be adjusted accordingly to reduce the proportion of water.

[0024] Preferably, the height of the pottery jar is greater than 2m. The heat energy source for in-vessel drying in the primary drying process includes: a hot air device and an electric heating device. The temperature of the hot air is 40°C - 50°C, the power of the electric heating device is 250w - 300w, the distance between the electric heating device and the inner bottom wall of the wet blank is 0.4m - 0.6m, and the drying time is 16h - 20h.

[0025] When the volume of the ceramic jar is large, especially when the height is high, it is difficult to ensure that the hot air reaches the inner bottom wall of the wet embryo only through the hot air device. Increasing the hot air speed may cause the wet embryo to shrink and crack. For example, the upper part of the wet embryo is closer to the hot air source, and the attenuation of the wind speed here is lower. When the wind speed is increased, under the influence of wind pressure and / or accelerated shrinkage, etc., the embryo body may crack. Therefore, the present invention adopts a combination of hot air and electric heating devices. The electric heating device can adopt a heating lamp, which is arranged close to the bottom, and its heat is mainly used for drying the bottom and the side wall close to the bottom, while the hot air is mainly used for drying the upper part of the wet embryo and the side wall close to the upper part. After baking the bottom in this way for 17.5 hours, it can reach the thickest part at the bottom corner of the wet blank, and the hardness measured by the Shore hardness tester reaches 80-90, and it will not cause over-soft cracking after dehumidifying the wet blank.

[0026] In order to make the heat shrinkage of each part of the wet embryo uniform, the present invention regulates the power of the electric heating device.

[0027] Preferably, the thickness of the bottom wall of the wet embryo gradually decreases from the edge to the center. The thickness of the bottom wall edge is 45mm - 50mm, and the thickness of the bottom wall center is 25mm - 30mm.

[0028] When demolding a large ceramic jar, it may cause molding defects. Therefore, on the premise of ensuring the same hardness of the bottom and the rest of the parts during the drying process, the present invention further reduces the risk of bottom cracking through the adjustment of the bottom thickness, reduces or avoids the use of waste clay from the corner of the recycled clay, and there is no need to process the flash and other recycled clay back to the raw material workshop.

[0029] Preferably, the temperature of the sintering process is 1100°C - 1200°C, and the sintering time is 50h - 72h.

[0030] The present invention has at least the following beneficial effects:

[0031] Through the improvement of the mud material ratio, the addition of the drying of the gypsum model, the improvement of the paste-water ratio of the gypsum model, and the improvement of the structure and drying process of the wet embryo, the present invention has achieved a significant reduction in the retention time of the wet embryo in the gypsum model, reduced energy consumption, and increased production capacity on the premise of ensuring the morphological stability of the wet embryo during demolding. Detailed Embodiments

[0032] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention.

[0033] Embodiment 1: A preparation process for an easily demoldable ceramic jar, including the following steps:

[0034] S100. Prepare a mud material by mixing the main materials and water. The main materials include raw materials and clinker, and the clinker accounts for 6 wt% of the main materials. The mud material is processed using a vacuum clay kneading technique with a vacuum degree of 0.1 MPa, and then aged for three days. The particle size of the main materials is 48 μm. The mass ratio of the main materials to water is 100:15.

[0035] S200. After the mud material is formed through a gypsum model, a green blank is obtained. The forming method is rolling forming.

[0036] S300. After the green blank is dried through a primary drying process, it is demolded to obtain a preform. After demolding, the gypsum model is dried again to a water content of 5 wt%.

[0037] The heat energy source for drying the gypsum model includes: waste heat from the kiln and a hot air device. The hot air device is arranged inside the green blank. The temperature of the waste heat from the kiln is 400 °C, the temperature of the hot air generated by the hot air device is 100 °C higher than the waste heat from the kiln, and the drying time is 22 h. The plaster-water ratio of the gypsum model is 100:40.

[0038] The height of the pottery jar is greater than 2 m. The heat energy source for drying inside the blank in the primary drying process includes: a hot air device and an electric heating device. The temperature of the hot air is 40 °C, the hot air velocity is 2.5 m / s, the power of the electric heating device is 250 w, the distance between the electric heating device and the inner bottom wall of the green blank is 0.4 m, and the drying time is 16 h.

[0039] The thickness of the bottom wall of the green blank gradually decreases from the edge to the center. The thickness of the bottom wall edge is 45 mm, and the thickness of the bottom wall center is 25 mm.

[0040] S400. After the preform is trimmed and glazed, and through a secondary drying process and a sintering process, a pottery jar is obtained.

[0041] The secondary drying process includes: slow drying at room temperature for 10 days, drying at 45 °C for 5 days, loading into the kiln when the moisture content at the bottom corner is less than 5%, drying at 800 °C for 20 hours, and starting sintering after the moisture content is lower than 1%.

[0042] The temperature of the sintering process is 1100 °C, and the sintering time is 72 h.

[0043] Example 2: A preparation process for an easily demoldable pottery jar, including the following steps:

[0044] S100. Prepare a mud material by mixing the main materials and water. The main materials include raw materials and clinker, and the clinker accounts for 10 wt% of the main materials. The mud material is processed using a vacuum clay kneading technique with a vacuum degree of 0.1 MPa, and then aged for three days. The particle size of the main materials is 58 μm. The mass ratio of the main materials to water is 100:18.

[0045] S200. After the mud material is formed by a plaster model, a green blank is obtained; the forming method is rolling forming.

[0046] S300. After the green blank is dried by a primary drying process, it is demolded to obtain a preform; after demolding, the plaster model is dried again until the water content is 8 wt%.

[0047] The heat energy source for drying the plaster model includes: the waste heat of the kiln and a hot air device, and the hot air device is arranged inside the green blank; the temperature of the waste heat of the kiln is 500 °C, the temperature of the hot air generated by the hot air device is 150 °C higher than the waste heat of the kiln, and the drying time is 18 h; the plaster-water ratio of the plaster model is 100:60.

[0048] The height of the pottery jar is greater than 2 m. The heat energy source for drying inside the blank in the primary drying process includes: a hot air device and an electric heating device. The temperature of the hot air is 50 °C, the hot air velocity is 4 m / s, the power of the electric heating device is 300 w, the distance between the electric heating device and the inner bottom wall of the green blank is 0.6 m, and the drying time is 16 h.

[0049] The thickness of the bottom wall of the green blank gradually decreases from the edge to the center. The thickness of the bottom wall edge is 50 mm, and the thickness of the bottom wall center is 30 mm.

[0050] S400. After the preform is trimmed and glazed, and through a secondary drying process and a sintering process, a pottery jar is obtained.

[0051] The secondary drying process includes: slow drying at room temperature for 10 days, drying at 45 °C for 5 days, loading into the kiln when the water content of the bottom corner is less than 5%, drying at 800 °C for 20 hours, and starting sintering after the water content is lower than 1%.

[0052] The temperature of the sintering process is 1200 °C, and the sintering time is 72 h.

[0053] Example 3: A preparation process for an easily demoldable pottery jar, comprising the following steps:

[0054] S100. Prepare a mud material by mixing the main materials and water. The main materials include: raw materials and clinker, and the clinker accounts for 8 wt% of the main materials; the mud material adopts vacuum clay refining technology with a vacuum degree of 0.1 MPa, and then is aged for three days; the particle size of the main materials is 50 μm; the mass ratio of the main materials to water is 100:16.

[0055] S200. After the mud material is formed by a plaster model, a green blank is obtained; the forming method is rolling forming.

[0056] S300. After the green blank is dried by a primary drying process, it is demolded to obtain a preform; after demolding, the plaster model is dried again until the water content is 6 wt%.

[0057] The heat energy sources for drying the gypsum model include: the waste heat of the kiln and the hot air device, and the hot air device is arranged inside the wet blank; the temperature of the waste heat of the kiln is 460 °C, the hot air temperature generated by the hot air device is 120 °C higher than the waste heat of the kiln, the drying time is 20 h; the paste-water ratio of the gypsum model is 100:50;

[0058] The height of the pottery jar is greater than 2 m. The heat energy sources for drying inside the blank in the primary drying process include: the hot air device and the electric heating device. The temperature of the hot air is 45 °C, the hot air velocity is 3.5 m / s, the power of the electric heating device is 270 w, the distance between the electric heating device and the inner bottom wall of the wet blank is 0.5 m, and the drying time is 17.5 h;

[0059] The thickness of the bottom wall of the wet blank gradually decreases from the edge to the center. The thickness of the bottom wall edge is 47 mm, and the thickness of the bottom wall center is 27 mm;

[0060] S400. After the preform is trimmed and glazed, a pottery jar is obtained through the secondary drying process and the sintering process;

[0061] The secondary drying process includes: slow drying at room temperature for 10 days, drying at 45 °C for 5 days, loading into the kiln when the moisture content of the bottom corner is less than 5%, drying at 800 °C for 20 hours, and starting sintering after the moisture content is lower than 1%;

[0062] The temperature of the sintering process is 1180 °C, and the sintering time is 65 h.

[0063] Comparative Example 1: A preparation process for an easily demoldable pottery jar, comprising the following steps:

[0064] S100. Prepare mud by mixing the main materials and water. The main materials include: raw materials and clinker, and the clinker accounts for 8 wt% of the main materials; the mud uses vacuum clay kneading technology with a vacuum degree of 0.1 MPa, and then ages for three days; the particle size of the main materials is 50 μm; the mass ratio of the main materials to water is 100:16;

[0065] S200. After the mud is formed through a gypsum model, a wet blank is obtained; the forming method is rolling forming;

[0066] S300. After the wet blank is dried through the primary drying process, it is demolded to obtain a preform; after demolding, the gypsum model is dried again until the water content is 6 wt%;

[0067] The heat energy sources for drying the gypsum model include: the waste heat of the kiln and the hot air device, and the hot air device is arranged inside the wet blank; the temperature of the waste heat of the kiln is 460 °C, the hot air temperature generated by the hot air device is 120 °C higher than the waste heat of the kiln, the drying time is 20 h; the paste-water ratio of the gypsum model is 100:50;

[0068] The height of the pottery jar is greater than 2m. The heat energy sources for in-ware drying in the primary drying process include: a hot air device and an electric heating device. The temperature of the hot air is 45°C, the hot air velocity is 3.5m / s, the power of the electric heating device is 270w, the distance between the electric heating device and the inner bottom wall of the wet ware is 0.5m, and the drying time is 17.5h;

[0069] The thickness of the bottom wall of the wet ware is 27mm;

[0070] S400. After the preform is trimmed and glazed, a pottery jar is obtained through a secondary drying process and a sintering process;

[0071] The secondary drying process includes: slow drying at room temperature for 10 days, drying at 45°C for 5 days, loading into the kiln when the moisture content at the bottom corner is less than 5%, drying at 800°C for 20 hours, and starting sintering after the moisture content is lower than 1%;

[0072] The temperature of the sintering process is 1180°C, and the sintering time is 65h.

[0073] Comparative Example 2: A preparation process for an easily demoldable pottery jar, including the following steps:

[0074] S100. Prepare a mud material by mixing the main materials and water. The main materials include: raw materials and clinker, and the clinker accounts for 8wt% of the main materials; the mud material uses vacuum clay kneading technology with a vacuum degree of 0.1MPa, and then is aged for three days; the particle size of the main materials is 50μm; the mass ratio of the main materials to water is 100:16;

[0075] S200. After the mud material is formed through a plaster mold, a wet ware is obtained; the forming method is roll forming;

[0076] S300. After the wet ware is dried through a primary drying process, it is demolded to obtain a preform; after demolding, the plaster mold is dried again until the moisture content is 6wt%;

[0077] The heat energy sources for drying the plaster mold include: the waste heat of the kiln and a hot air device, and the hot air device is arranged inside the wet ware; the temperature of the waste heat of the kiln is 460°C, the temperature of the hot air generated by the hot air device is the same as that of the waste heat of the kiln, the drying time is 20h; the plaster-water ratio of the plaster mold is 100:50;

[0078] The height of the pottery jar is greater than 2m. The heat energy sources for in-ware drying in the primary drying process include: a hot air device and an electric heating device. The temperature of the hot air is 45°C, the hot air velocity is 3.5m / s, the power of the electric heating device is 270w, the distance between the electric heating device and the inner bottom wall of the wet ware is 0.5m, and the drying time is 17.5h;

[0079] The thickness of the wet embryo bottom wall gradually decreases from the edge to the center. The thickness of the bottom wall edge is 47 mm, and the thickness of the bottom wall center is 27 mm;

[0080] S400. After the preform is trimmed and glazed, a pottery jar is obtained through a secondary drying process and a sintering process;

[0081] The secondary drying process includes: slow drying at room temperature for 10 days, drying at 45 °C for 5 days, loading into the kiln when the moisture content of the bottom corner is less than 5%, drying at 800 °C for 20 hours, and starting sintering after the moisture content is lower than 1%;

[0082] The temperature of the sintering process is 1180 °C, and the sintering time is 65 h.

[0083] Comparative Example 3: A preparation process for an easily demoldable pottery jar, comprising the following steps:

[0084] S100. Prepare a mud material by mixing the main materials and water. The main materials include raw materials and clinker, and the clinker accounts for 8 wt% of the main materials; the mud material adopts vacuum clay refining technology with a vacuum degree of 0.1 MPa, and then is aged for three days; the particle size of the main materials is 50 μm; the mass ratio of the main materials to water is 100:22;

[0085] S200. After the mud material is formed by a plaster model, a wet embryo is obtained; the forming method is rolling forming;

[0086] S300. After the wet embryo is dried by a primary drying process, it is demolded to obtain a preform; after demolding, the plaster model is dried again to a moisture content of 6 wt%;

[0087] The heat source for drying the plaster model includes: waste heat from the kiln and a hot air device, and the hot air device is arranged inside the wet embryo; the temperature of the waste heat from the kiln is 460 °C, the hot air temperature generated by the hot air device is 120 °C higher than the waste heat from the kiln, and the drying time is 20 h; the plaster-water ratio of the plaster model is 100:50;

[0088] The height of the pottery jar is greater than 2 m. The heat source for drying inside the embryo in the primary drying process includes: a hot air device and an electric heating device. The temperature of the hot air is 45 °C, the hot air velocity is 3.5 m / s, the power of the electric heating device is 270 w, the distance between the electric heating device and the inner bottom wall of the wet embryo is 0.5 m, and the drying time is 17.5 h;

[0089] The thickness of the wet embryo bottom wall gradually decreases from the edge to the center. The thickness of the bottom wall edge is 47 mm, and the thickness of the bottom wall center is 27 mm;

[0090] S400. After the preform is trimmed and glazed, a pottery jar is obtained through a secondary drying process and a sintering process;

[0091] The secondary drying process includes: slow drying at room temperature for 10 days, drying at 45°C for 5 days, loading into the kiln when the moisture content at the bottom corner is less than 5%, drying at 800°C for 20 hours, and starting sintering after the moisture content is lower than 1%;

[0092] The temperature of the sintering process is 1180°C and the sintering time is 65h.

[0093] Comparative Example 4: A preparation process for an easily demoldable pottery jar, comprising the following steps:

[0094] S100. Prepare a mud material by mixing the main materials and water. The main materials include raw materials and clinker, and the clinker accounts for 8wt% of the main materials; the mud material uses vacuum clay kneading technology with a vacuum degree of 0.1MPa, and then ages for three days; the particle size of the main materials is 50μm; the mass ratio of the main materials to water is 100:16;

[0095] S200. After the mud material is formed by a gypsum model, a wet blank is obtained; the forming method is rolling forming;

[0096] S300. After the wet blank is dried by a primary drying process, it is demolded to obtain a preform; after demolding, the gypsum model is dried again to a moisture content of 6wt%;

[0097] The heat energy source for drying the gypsum model includes: waste heat from the kiln and a hot air device, and the hot air device is arranged inside the wet blank; the temperature of the waste heat from the kiln is 460°C, the hot air temperature generated by the hot air device is 120°C higher than the waste heat from the kiln, and the drying time is 20h; the plaster-water ratio of the gypsum model is 100:70;

[0098] The height of the pottery jar is greater than 2m. The heat energy source for drying inside the blank in the primary drying process includes: a hot air device and an electric heating device. The temperature of the hot air is 45°C, the hot air velocity is 3.5m / s, the power of the electric heating device is 270w, the distance between the electric heating device and the inner bottom wall of the wet blank is 0.5m, and the drying time is 17.5h;

[0099] The thickness of the bottom wall of the wet blank gradually decreases from the edge to the center. The thickness of the bottom wall edge is 47mm, and the thickness of the bottom wall center is 27mm;

[0100] S400. After the preform is trimmed and glazed, and through the secondary drying process and sintering process, a pottery jar is obtained;

[0101] The secondary drying process includes: slow drying at room temperature for 10 days, drying at 45°C for 5 days, loading into the kiln when the moisture content at the bottom corner is less than 5%, drying at 800°C for 20 hours, and starting sintering after the moisture content is lower than 1%;

[0102] The temperature of the sintering process is 1180°C and the sintering time is 65h.

[0103] Comparative Example 5: A preparation process of an easily demouldable pottery jar, comprising the following steps:

[0104] S100. Prepare a mud material by mixing the main materials and water. The main materials include raw materials and clinker, and the clinker accounts for 8 wt% of the main materials; the mud material is processed by vacuum pugging technology with a vacuum degree of 0.1 MPa, and then aged for three days; the particle size of the main materials is 50 μm; the mass ratio of the main materials to water is 100:16;

[0105] S200. After the mud material is formed by a plaster model, a wet blank is obtained; the forming method is rolling forming;

[0106] S300. After the wet blank is dried by a primary drying process, it is demoulded to obtain a preform; after demoulding, the plaster model is dried again to a water content of 6 wt%;

[0107] The heat energy source for drying the plaster model includes: waste heat from the kiln and a hot air device, and the hot air device is arranged inside the wet blank; the temperature of the waste heat from the kiln is 460 °C, the hot air temperature generated by the hot air device is 120 °C higher than the waste heat from the kiln, and the drying time is 20 h; the plaster-water ratio of the plaster model is 100:50;

[0108] The height of the pottery jar is greater than 2 m, and the heat energy source for drying inside the blank in the primary drying process includes: a hot air device, the temperature of the hot air is 45 °C, the hot air velocity is 3.5 m / s, and the drying time is 17.5 h;

[0109] The thickness of the bottom wall of the wet blank gradually decreases from the edge to the center, the thickness of the bottom wall edge is 47 mm, and the thickness of the bottom wall center is 27 mm;

[0110] S400. After the preform is trimmed and glazed, and through a secondary drying process and a sintering process, a pottery jar is obtained;

[0111] The secondary drying process includes: slow drying at room temperature for 10 days, drying at 45 °C for 5 days, loading into the kiln when the water content of the bottom corner is less than 5%, drying at 800 °C for 20 hours, and starting sintering after the water content is lower than 1%;

[0112] The temperature of the sintering process is 1180 °C, and the sintering time is 65 h.

[0113] Comparative Example 6: A preparation process of an easily demouldable pottery jar, comprising the following steps:

[0114] S100. Prepare a mud material by mixing the main materials and water. The main materials include raw materials and clinker, and the clinker accounts for 8 wt% of the main materials; the mud material is processed by vacuum pugging technology with a vacuum degree of 0.1 MPa, and then aged for three days; the particle size of the main materials is 65 μm; the mass ratio of the main materials to water is 100:16;

[0115] S200. After the mud material is formed through a plaster model, a green blank is obtained; the forming method is rolling forming;

[0116] S300. After the green blank is dried through a primary drying process, it is demolded to obtain a preform; after demolding, the plaster model is dried again to a water content of 6 wt%;

[0117] The heat energy source for drying the plaster model includes: waste heat from the kiln and a hot air device, and the hot air device is arranged inside the green blank; the temperature of the waste heat from the kiln is 460 °C, the hot air temperature generated by the hot air device is 120 °C higher than the waste heat from the kiln, and the drying time is 20 h; the plaster-water ratio of the plaster model is 100:50;

[0118] The height of the pottery jar is greater than 2 m. The heat energy source for drying inside the blank in the primary drying process includes: a hot air device and an electric heating device. The temperature of the hot air is 45 °C, the hot air velocity is 3.5 m / s, the power of the electric heating device is 270 w, the distance between the electric heating device and the inner bottom wall of the green blank is 0.5 m, and the drying time is 17.5 h;

[0119] The thickness of the bottom wall of the green blank gradually decreases from the edge to the center. The thickness of the bottom wall edge is 47 mm, and the thickness of the bottom wall center is 27 mm;

[0120] S400. After the preform is trimmed and glazed, and through a secondary drying process and a sintering process, a pottery jar is obtained;

[0121] The secondary drying process includes: slow drying at room temperature for 10 days, drying at 45 °C for 5 days, loading into the kiln when the bottom corner moisture content is less than 5%, drying at 800 °C for 20 hours, and starting sintering after the moisture content is lower than 1%;

[0122] The temperature of the sintering process is 1180 °C, and the sintering time is 65 h.

[0123] Experiment:

[0124] Raw materials:

[0125] The raw material composition is 70% silicon dioxide, 22% aluminum oxide, 5.5% iron oxide, and the balance is the total content of calcium, magnesium, potassium, and sodium. The total content of calcium, magnesium, potassium, and sodium refers to the total amount of compounds containing calcium ions, magnesium ions, potassium ions, and sodium ions.

[0126] The clinker composition is 45% mullite phase, 35% glass phase (monovalent potassium and sodium, divalent calcium and magnesium), 9% free quartz, 6% iron metal oxide, and 5% other impurities.

[0127] Experiment 1: The pottery jars were prepared according to the pottery jar preparation processes provided in Examples 1-3 and Comparative Examples 1-6. The height of the pottery jars was 2.5 m, and then the apparent quality of the pottery jars was detected. Among them, the pottery jars prepared according to the pottery jar preparation processes provided in Examples 1-3 had no cracks, no bubbles, and no deformation. Certain bottom deformations occurred in Comparative Examples 1-6. The applicant conjectured that it was related to insufficient drying before demolding. The yield is shown in Table 1.

[0128] Table 1

[0129] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Yield 98.1％ 98.6％ 99.2％ 75.4％ 86.7％ Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Yield 79.8％ 91.7％ 83.4％ 93.2％

[0130] From the test results of Examples 1-3, it can be seen that the pottery jars prepared by using the pottery jar preparation processes provided in Examples 1-3 had a high yield.

[0131] From the comparison between Comparative Examples 1-6 and Example 3, it can be seen that the structure of the wet embryo bottom wall, the drying process of the gypsum model, the ratio of the main material to water, the paste-water ratio, the primary drying process, and the particle size of the main material all affect the appearance quality of the product.

[0132] Experiment 2: The pottery jars were prepared according to the pottery jar preparation processes provided in Examples 1-3 and Comparative Examples 1-6, and then the performance of the pottery jars was detected. The average value was taken after each group was tested 5 times. The test results are shown in Table 2.

[0133] Table 2

[0134] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Flexural Strength (MPa) 187.6 196.4 212.3 125.7 137.8 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Flexural Strength (MPa) 128.8 164.2 153.5 169.1

[0135] From the test results of Examples 1-3, it can be seen that the pottery jars prepared by using the pottery jar preparation processes provided in Examples 1-3 had good strength performance.

[0136] From the comparison between Comparative Examples 1-6 and Example 3, it can be seen that the structure of the wet embryo bottom wall, the drying process of the gypsum model, the ratio of the main material to water, the paste-water ratio, the primary drying process, and the particle size of the main material all affect the strength performance of the product. The applicant conjectured that the reason was that the bubbles and cracks in the pottery jar structure affected the strength performance of the pottery jar.

[0137] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, various changes and modifications can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A process for preparing a pottery jar that is easy to demould, characterized in that: The following steps are involved: S100, preparing a main material and water to obtain a mud material, wherein the main material comprises: a raw material and a clinker, wherein the clinker accounts for 6wt%-10wt% of the main material; S200, the mud material is formed by a plaster model to obtain a wet embryo; S300, the wet embryo is dried through a primary drying process, and then demoulded to obtain a preform; S400, the preform is subjected to a secondary drying process and a sintering process to obtain a pottery jar.

2. The pottery jar preparation process according to claim 1, characterized in that: The step S300 includes: drying the plaster model again to a water content of 5wt%-8wt% after demoulding.

3. The pottery jar preparation process according to claim 2, characterized in that: The heat energy sources for drying the plaster model include: waste heat from the kiln furnace and a hot air device, and the hot air device is arranged inside the wet embryo.

4. The pottery jar preparation process according to claim 3, characterized in that: The temperature of the waste heat from the kiln furnace is 400°C-500°C, the temperature of the hot air generated by the hot air device is 100°C-150°C higher than the waste heat from the kiln furnace, and the drying time is 18h-22h.

5. The pottery jar preparation process according to claim 1, characterized in that: The plaster-to-water ratio of the plaster model is 100:(40-60).

6. The process for preparing a pottery jar according to any one of claims 1 to 5, characterized in that: The particle size of the main material is 48 μm-58 μm.

7. The pottery jar preparation process according to claim 6, characterized in that: The mass ratio of the main material to water in the S100 is 100:(15-18).

8. The pottery jar preparation process according to claim 6, characterized in that: The height of the pottery jar is greater than 2m. The sources of heat energy for drying the embryo in the primary drying process include: a hot air device and an electric heating device. The temperature of the hot air is 40°C-50°C, and the wind speed of the hot air is 2.5m / s-4m / s; the power of the electric heating device is 250w-300w, and the distance between the electric heating device and the bottom wall of the wet embryo is 0.4m-0.6m. The drying time is 16h-20h.

9. The pottery jar preparation process according to claim 6, characterized in that: The thickness of the wet embryo bottom wall gradually decreases from the edge to the center, the thickness of the bottom wall edge is 45mm-50mm, and the thickness of the bottom wall center is 25mm-30mm.

10. The pottery jar preparation process according to claim 6, characterized in that: The temperature of the sintering process is 1100° C.-1200° C., and the sintering time is 50 h-72 h.