Large volume thin body green ceramic and method of making same

Abstract

The present application relates to the field of ceramic and its preparation method, and particularly relates to a large-volume thin-body green ceramic and its preparation method, wherein the green body is prepared by freeze-drying, and a reinforcing layer is adhered to the inner wall of the green body, so that the green body is not easy to collapse or be damaged during demolding, and the success rate of green body forming is greatly improved; during the preparation of slurry and the injection of slurry, vacuum stirring and ultrasonic vibration are adopted to effectively remove air bubbles in the slurry, and the density and strength of the green body are improved; when the crystalline glaze is matched with the mint green glaze, white crystals are formed on the glaze surface, the crystalline glaze has large fluidity, and the crystalline glaze flows downward during the glaze firing process to form local vertical lines or mottling, which is similar to frost, so that the upper half of the glaze surface presents a translucent moss mottling and white frost mottling interlaced glaze surface effect, and with the help of the thin wall of the green body, when the green body is irradiated by a light source, the light source transmits through the green body to present a light spot on the local glaze surface, which is unique and beautiful.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ceramic and its preparation method, in particular to large volume thin body ceramic and its preparation method. BACKGROUND

[0002] Thin body porcelain is also called eggshell porcelain, which is one of the famous traditional porcelain varieties in Jingdezhen. The porcelain body is thin like an eggshell, transparent, and made of pure glaze. The production of thin body porcelain requires more than 40 processes, all of which are done by hand, and is fired three times. The body is polished repeatedly for more than 100 times to make it 0.5mm thick from 2-3mm thick rough body. The body thickness is mostly within 1mm, which is called "thin as a cicada's wing, bright as glass, and light as a cloud". It is light, beautiful, delicate, and transparent, which is one of the traditional art porcelain in Jingdezhen, China. The body of thin body porcelain is flexible before it is completely dried. During the subsequent body polishing or transportation, the body is easy to deform or even collapse, especially for large volume thin body. In addition, the traditional thin body porcelain processing technology needs to be polished to the required thickness after the body is formed, and the process is basically completed by hand, which requires high skills of the master, long production cycle, and is not suitable for industrialization and mass production. Therefore, the present application is produced. SUMMARY

[0003] An object of the present application is to solve at least the above problems by large volume thin body ceramic and its preparation method.

[0004] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a large volume thin body ceramic, including a body and a surface glaze, the raw materials of the body include the following components by weight: 30-35 parts of kaolin, 20-25 parts of feldspar, 10-15 parts of quartz stone, 6-8 parts of industrial alumina, and 10-12 parts of Suzhou soil.

[0005] Preferably, the upper half of the surface glaze is covered with transparent glaze, mint green glaze and crystal glaze from bottom to top, and the lower half is covered with transparent glaze.

[0006] Preferably, the raw materials of the bright glaze include the following components by weight: 35-40 parts of nepheline syenite, 15-20 parts of silicon dioxide, 15-20 parts of light rutile, 15-20 parts of borate, 13-15 parts of kaolin, 7-9 parts of wollastonite, and 2-3 parts of zinc oxide.

[0007] Preferably, the raw materials of the mint green glaze include, by weight, nepheline syenite 30-35 parts, kaolin 15-20 parts, silica 20-25 parts, ball clay 12-15 parts, dolomite 8-12 parts, strontium carbonate 4-6 parts, lithium carbonate 2-3 parts, copper carbonate 2-3 parts, and titanium dioxide 1-2 parts.

[0008] Preferably, the raw materials of the crystalline glaze include, by weight, feldspar 35-40 parts, kaolin 20-25 parts, calcium carbonate 15-20 parts, strontium carbonate 10-12 parts, transparent filler 20-22 parts, talc 10-12 parts, zinc oxide 5-7 parts, dolomite 8-9 parts, lithium carbonate 3-5 parts, titanium dioxide 2-3 parts, and bentonite 6-8 parts.

[0009] The method for preparing a large-volume thin-body green body ceramic includes the following steps:

[0010] Step a, configuring a green body and a reinforcing agent;

[0011] Step b, slip casting a green body;

[0012] Step c, forming a reinforcing layer on the inner wall of the green body;

[0013] Step d, freezing the gypsum mold and the green body;

[0014] Step e, demolding the gypsum mold to take out the green body;

[0015] Step f, vacuumizing the green body;

[0016] Step g, heating and drying in a vacuum environment to obtain a dried and shaped green body;

[0017] Step h, putting the green body into a kiln for bisque firing;

[0018] Step i, applying a glaze to the surface of the green body;

[0019] Step j, putting the green body into a kiln for glaze firing.

[0020] Preferably, in step a, the green body slurry is stirred at a low temperature of 3-8℃ and vacuum defoaming is performed every 10 min; in step b, the green body slurry is injected into the gypsum mold, the gypsum mold is rotated to make the green body slurry adhere to the inner wall of the gypsum mold to form a green body, and ultrasonic waves are applied during slip casting, and finally the excess green body is poured out.

[0021] Preferably, in step c, the reinforcing agent is injected into the gypsum mold, the gypsum mold is rotated to make the reinforcing agent adhere to the inner side of the body, and a heating rod is inserted into the injection port to heat during the rotation of the gypsum mold, so that a reinforcing layer is formed on the inner side of the body; the raw materials of the reinforcing agent include, by weight, 10-12 parts of carboxymethyl cellulose glue and 15-16 parts of polypropylene short fibers; in step d, the temperature of the freezing chamber is -10 to -15 DEG C, and the freezing time is 7-9 hours.

[0022] Preferably, in step h, the biscuit firing process is as follows: the temperature is raised to 350 DEG C within 1.5-2 hours, and then kept for 3 hours, then the temperature is raised to 600 DEG C within 2 hours, and then kept for 3-4 hours, and then the biscuit is naturally cooled; in step i, the bright glaze is applied to the whole body, then the mint green glaze is applied to the lower half of the top of the body, and finally the crystalline glaze is applied to the lower third of the top of the body.

[0023] Preferably, in step j, in the glaze firing process, the temperature is raised to 950-1050 DEG C for 3-4 hours, then raised to 1050-1100 DEG C for 1-1.2 hours, then raised to 1100-1200 DEG C for 3-4 hours, and then kept at 1200 DEG C for 4-5 hours.

[0024] As can be seen from the above description, the large-volume thin-body ceramic body and the preparation method thereof have the following beneficial effects: the body is dried by freezing, and a reinforcing layer is adhered to the inner wall of the body, so that the body is not easy to collapse or be damaged during demolding, the success rate of body forming is greatly improved, the slurry is prepared and injected by vacuum stirring and ultrasonic vibration, air bubbles in the slurry are effectively removed, the density and strength of the body are improved, and the body is suitable for firing; the body is prepared by injection molding, and the production efficiency is high; when the crystalline glaze and the mint green glaze are matched, white crystals are formed on the glaze surface, the crystalline glaze has high fluidity, flows downward during glaze firing, and forms local vertical lines or mottling, which looks like frost, so that the upper half of the glaze surface presents a translucent moss mottling and white frost mottling interlaced glaze surface effect, and the thin wall of the body makes the light source penetrate the body and present a light spot on the local glaze surface when the light source is illuminated inside the body, which has unique beauty. DETAILED DESCRIPTION

[0025] The application will be further described in the following specific embodiments.

[0026] In order to make the technical means, creative features, purposes and effects of the application easy to understand, the application will be further described in the following specific embodiments.

[0027] The large-volume thin-body blank ceramic comprises a blank body and a surface glaze, and raw materials of the blank body comprise, in parts by weight, the following components: kaolin 30-35 parts, feldspar 20-25 parts, quartz stone 10-15 parts, industrial alumina 6-8 parts, Suzhou clay 10-12 parts.

[0028] The upper half of the surface glaze is sequentially covered from bottom to top with transparent glaze, mint green glaze and crystal glaze, and the lower half is covered with transparent glaze. The transparent glaze forms a bright white glaze surface effect on the lower half of the blank body after firing. The mint green glaze forms a translucent green glaze surface effect after firing, and the mint green glaze has large fluidity and forms green vertical lines. When the crystal glaze is matched with the mint green glaze, white crystals are formed on the glaze surface. The crystal glaze has large fluidity and flows downward during the glazing process to form local vertical lines or mottling, which looks like white frost. Therefore, the overall glaze surface has a translucent moss mottling and white frost mottling effect. When the blank body is illuminated by a light source, the light source transmits through the blank body to form light spots on the local glaze surface, and the light spots and the moss mottling interweave, which has unique beauty.

[0029] The raw materials of the bright glaze comprise, in parts by weight, the following components: nepheline syenite 35-40 parts, silicon dioxide 15-20 parts, light gold rutile 15-20 parts, borate 15-20 parts, kaolin 13-15 parts, wollastonite 7-9 parts, and zinc oxide 2-3 parts.

[0030] The raw materials of the mint green glaze comprise, in parts by weight, the following components: nepheline syenite 30-35 parts, kaolin 15-20 parts, silicon dioxide 20-25 parts, ball clay 12-15 parts, dolomite 8-12 parts, strontium carbonate 4-6 parts, lithium carbonate 2-3 parts, copper carbonate 2-3 parts, and titanium dioxide 1-2 parts.

[0031] The raw materials of the crystal glaze comprise, in parts by weight, the following components: feldspar 35-40 parts, kaolin 20-25 parts, calcium carbonate 15-20 parts, strontium carbonate 10-12 parts, transparent filler 20-22 parts, talc 10-12 parts, zinc oxide 5-7 parts, dolomite 8-9 parts, lithium carbonate 3-5 parts, titanium dioxide 2-3 parts, and bentonite 6-8 parts. When the crystal glaze is matched with the mint green glaze, white crystals are formed on the glaze surface. The crystal glaze has large fluidity and flows from the mint green glaze during the glazing process to form white frost mottling.

[0032] The preparation method of the large-volume thin-body blank ceramic comprises the following steps:

[0033] Step a, configuring a blank and a reinforcing agent;

[0034] Step b, slip casting body; the traditional thin body processing technology needs to draw the body after forming the body, and then to repair the body to the required thickness, the process is basically completed by hand, the skill of the master is required, the production cycle is long, not suitable for industrialization and batch production, and the quality stability is poor; the body is prepared by the slip casting method, the production efficiency is high, and the large volume thin body can be produced;

[0035] Step c, forming a reinforcing layer on the inner wall of the body;

[0036] Step d, freezing the gypsum mold and the body;

[0037] Step e, demolding the gypsum mold and taking out the body; since the body is frozen in the above steps, the body has good strength, and the reinforcing layer adhered to the inner wall of the body, so that the body is not easy to collapse or damage during demolding, greatly improving the success rate of body forming.

[0038] Step f, vacuumizing the body;

[0039] Step g, heating and drying in a vacuum environment to obtain a dried and shaped body; since the body has a certain flexibility after forming, the body is dried by the freezing and drying method, which can help the thin wall body not to deform between the forming and the complete drying, especially suitable for drying and forming of large volume, large height thin wall body, such as drying of high vase body and other products. Specifically, the freezing and drying adopts the above three processes of freezing, vacuumizing and heating to dry the body. First, the body to be dried is placed in a freezer, and the water in the body is converted from liquid to solid during freezing, and the body is solidified, then the body is placed in a vacuum box to vacuumize, and heated in a vacuum state, so that the frozen water changes from solid to gas, finally achieving the purpose of drying, and ensuring that the body maintains high stability during drying.

[0040] Step h, putting the body into the kiln for biscuit firing;

[0041] Step i, glazing the surface of the body;

[0042] Step j, glaze firing in the kiln.

[0043] In step a, the green body slurry is stirred at a low temperature of 3-8℃ and vacuum degassing is performed by vacuumizing every 10 minutes; in step b, the green body slurry is injected into the gypsum mold, the gypsum mold is rotated to make the green body slurry adhere to the inner wall of the gypsum mold to form a green body, ultrasonic waves are applied during the injection molding process, and finally the excess green body is poured out. The degassing time is controlled so that good degassing effect can be obtained and the water in the slurry can not evaporate excessively under vacuum. The thickness of the green body is controlled to be between 1-1.5mm. During the injection molding process, the ultrasonic vibration makes the bubbles break, thereby removing the bubbles in the slurry to improve the tightness of the green body and further improve the strength of the green body.

[0044] In step c, the reinforcing agent is injected into the gypsum mold, the gypsum mold is rotated to make the reinforcing agent adhere to the inner side of the green body, a heating rod is inserted into the injection port to heat during the rotation of the gypsum mold, and a reinforcing layer is formed on the inner side of the green body; the raw materials of the reinforcing agent include, by weight, carboxymethyl cellulose 10-12 parts and polypropylene short fiber 15-16 parts; in step d, the temperature of the freezing chamber is -10 to -15℃, and the freezing time is 7-9 hours. The reinforcing layer adhered to the inner layer of the green body protects the green body, avoids the thin-walled green body from breaking or collapsing during the subsequent demolding process, and the components of the reinforcing layer are high molecular compounds which are decomposed completely during the sintering process of the green body, leaving only the thin-walled green body. During the freezing process, the water in the green body changes from liquid to solid, so the ceramic raw materials are bonded, the green body is strengthened without drying, and the green body is not easily damaged during demolding.

[0045] The sintering process is as follows: the temperature is raised to 350℃ in 1.5-2 hours, kept for 3 hours, then raised to 600℃ in 2 hours, kept for 3-4 hours, and naturally cooled; in step i, the green body is applied with a bright glaze, then a mint green glaze is applied from the top half to the bottom of the green body, and finally a crystal glaze is applied from the top third to the bottom of the green body. The sintering process has a large exothermic peak at 350℃, and the decomposition reaction of organic matter mainly occurs at this stage, so slow heating to this temperature is required and a certain period of time is needed for heat preservation. After sintering, the reinforcing layer adhered to the inside of the green body is completely burned and decomposed, the green body is sintered, and during the glazing process, the mint green glaze and the crystal glaze flow downward to form vertical lines, the crystal glaze crystallizes on the surface of the mint green glaze to form white streaks, and the transparent glaze covers the lower half of the green body. Therefore, the upper half of the glaze surface of the green body presents a green-based imitation bamboo joint pattern covered with white frost, and the lower half is a white transparent glaze surface. When the light source is incident into the green body, green and white light spots are formed on the upper half of the green body through the translucent glaze surface, and a bright glaze effect is presented on the lower half.

[0046] During the process of glaze firing: the temperature rising time from 950 to 1050℃ is 3-4 hours, the temperature rising time from 1050 to 1100℃ is 1-1.2 hours, the temperature rising time from 1100 to 1200℃ is 3-4 hours, and the temperature holding time at 1200℃ is 4-5 hours. The shrinkage of the ceramic is obvious in the temperature range between 950-1050℃ and 1100-1200℃, so the temperature rising should be relatively slow in the two temperature ranges, otherwise the internal gas cannot be discharged in time due to the too fast shrinkage, thus closed pores are formed in the ceramic, and the strength of the ceramic is reduced or cracking occurs. And around 1000-1200℃, liquid phase appears and the ceramic forming reaction starts to occur, by reasonably controlling the temperature rising rate, the smooth growth of the crystal grains and the effective discharge of the pores are ensured, so that the strength of the ceramic is high enough.

[0047] The above merely describes several specific embodiments of the present application, but the design concept of the present application is not limited thereto, and any non-essential modification of the present application by using the concept should be regarded as an infringement of the protection scope of the present application.

Claims

1. A method for preparing a large-volume thin green ceramic, characterized in that: The steps include: Step a, preparing green body slurry and reinforcing agent; Step b, slip casting to form a green body; Step c, forming a reinforcement layer on the inner wall of the blank; Step d, freezing the plaster mold and the blank; Step e, demoulding the plaster mold and taking out the green body; Step f, vacuuming the green body; Step g, heating and drying under a vacuum environment to obtain a dried and shaped green body; Step h: placing the green body into a kiln for biscuit firing; Step i, glazing the surface of the green body; Step j, placing in kiln for glaze firing; In step a, the green body slurry is stirred at a low temperature of 3 to 8° C. and subjected to vacuum degassing, with vacuuming performed every 10 minutes. In step b, the green body slurry is injected into a plaster mold, and the plaster mold is rotated so that the green body slurry adheres to the inner wall of the plaster mold to form a green body. Ultrasonic waves are applied during the slip injection molding process, and excess green body is finally poured out. In step c, a reinforcing agent is injected into the plaster mold, and the plaster mold is rotated to allow the reinforcing agent to adhere to the inner side of the green body. During the rotation of the plaster mold, a heating rod is inserted through the grouting port to heat the green body, thereby forming a reinforcing layer on the inner side of the green body. The raw materials of the reinforcing agent include the following components, calculated by weight: 10-12 parts carboxymethyl cellulose glue and 15-16 parts polypropylene staple fibers. In step d, the temperature of the freezing chamber is -10 to -15 degrees Celsius, and the freezing time is 7-9 hours. In step h, the bisque firing process is as follows: heating to 350° C. within 1.5-2 hours, holding at that temperature for 3 hours, then heating to 600° C. within 2 hours, holding at that temperature for 3-4 hours, and naturally cooling; in step i, applying a bright glaze to the entire body, then applying a mint green glaze to the lower half of the top of the body, and finally applying a crystalline glaze to the lower third of the top of the body; In step j, during the glaze firing process, the heating time from 950 to 1050°C is 3-4 hours, the heating time from 1050 to 1100°C is 1-1.2 hours, the heating time from 1100 to 1200°C is 3-4 hours, and the temperature is kept at 1200°C for 4-5 hours; The large-volume thin-body ceramic comprises a body and a glaze. The raw materials of the body include the following components in parts by weight: 30-35 parts of kaolin, 20-25 parts of feldspar, 10-15 parts of quartz, 6-8 parts of industrial alumina, and 10-12 parts of Suzhou clay.

2. The method for preparing a large-volume thin green ceramic according to claim 1, characterized in that: The raw materials of the bright glaze include the following components in parts by weight: 35-40 parts of nepheline orthoclase, 15-20 parts of silicon dioxide, 15-20 parts of light rutile, 15-20 parts of borate, 13-15 parts of kaolin, 7-9 parts of wollastonite, and 2-3 parts of zinc oxide.

3. The method for preparing a large-volume thin-green ceramic according to claim 1, wherein: The raw materials of the mint green glaze include the following components in parts by weight: 30-35 parts of nepheline orthoclase, 15-20 parts of kaolin, 20-25 parts of silicon dioxide, 12-15 parts of ball clay, 8-12 parts of dolomite, 4-6 parts of strontium carbonate, 2-3 parts of lithium carbonate, 2-3 parts of copper carbonate, and 1-2 parts of titanium dioxide.

4. The method for preparing a large-volume thin-green ceramic according to claim 1, wherein: The raw materials of the crystalline glaze include the following components in parts by weight: 35-40 parts of feldspar, 20-25 parts of kaolin, 15-20 parts of calcium carbonate, 10-12 parts of strontium carbonate, 20-22 parts of transparent filler, 10-12 parts of talc, 5-7 parts of zinc oxide, 8-9 parts of dolomite, 3-5 parts of lithium carbonate, 2-3 parts of titanium dioxide, and 6-8 parts of bentonite.