Peeled cracked glaze ceramic and preparation method thereof

Abstract

The invention relates to the technical field of ceramics, in particular to peeled cracked glaze ceramic and a preparation method thereof.The peeled cracked glaze ceramic comprises a green body, the green body sequentially comprises an upper green body, a middle green body and a lower green body from top to bottom, the upper green body and the lower green body are covered with black volcanic glaze, and cracks are distributed on the surface of the middle green body. During glaze firing, an upper blank and a lower blank are covered with black volcanic glaze, a middle blank is covered with stripping glaze, during cooling, the stripping glaze is cracked due to the fact that the expansion coefficient of the stripping glaze is lower than that of a blank body, the surface layer of the middle blank is driven to form cracks, then stripping operation is conducted on the stripping glaze, the white middle blank is exposed, and black cracks are distributed on the middle blank. The black volcanic glaze covers the surfaces of the upper blank and the lower blank, and the annular dents of the upper blank and the lower blank can release stress, so that the black volcanic glaze is not easy to crack; the upper and lower parts of the whole prepared ceramic product are covered with black glazes, and the middle part is a white green body without glazes and with black cracks, so that the prepared ceramic product has a very strong contrast feeling and a unique artistic effect on the whole.

Description

Technical Field

[0001] The invention relates to the technical field of ceramics, and in particular to peeling crack glaze ceramics and a preparation method thereof. Background Art

[0002] Crackle glaze is an artistic glaze with a unique decorative effect. It is named for the natural cracking texture on its surface. These cracks have different shapes, such as ice cracks, crab claw patterns, fish roe patterns, etc., which add a different kind of beauty and artistic value to ceramics. The formation of crackle glaze is based on the difference in thermal expansion coefficients between the glaze and the body. Generally speaking, the thermal expansion coefficient of the glaze is greater than that of the body. During the firing process of ceramics, when the temperature rises, the glaze and the body expand at the same time; and in the cooling stage, the glaze shrinks more than the body due to its large thermal expansion coefficient, thus generating tensile stress on the glaze surface. When this tensile stress exceeds the tensile strength of the glaze, the glaze surface will crack and form various cracks. It can be seen from this that in the traditional ceramic preparation process, if you want to achieve a crack-like effect, you can only achieve it on the basis of the glaze surface, and its expression form is relatively single. In view of this, this case is generated. Summary of the invention

[0003] An object of the present invention is to solve at least the above-mentioned problems by exfoliating cracked glaze ceramics and a method for preparing the same.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: peeling crack glaze ceramics, including a body, the body including an upper body, a middle body and a lower body from top to bottom, the upper body and the lower body are covered with black volcanic glaze, and cracks are distributed on the surface of the middle body.

[0005] Preferably, the raw materials of the green body include the following components in parts by weight: 30-40 parts of kaolin, 20-30 parts of calcined clay, 20-25 parts of feldspar powder, 10-15 parts of quartz powder, 5-8 parts of borax, 10-13 parts of white lead, 5-8 parts of soda ash, 7-9 parts of cassiterite, and 6-8 parts of Suzhou soil.

[0006] Preferably, annular indentations are distributed on the surfaces of the upper and lower blanks, and the raw materials of the black volcanic glaze include the following components in parts by weight: 4-6 parts of chromium oxide, 4-6 parts of iron oxide, 2-4 parts of nickel oxide, 20-25 parts of quartz, 35-40 parts of feldspar, 20-25 parts of kaolin, and 10-14 parts of calcium carbonate.

[0007] Preferably, a metal piece is embedded in the middle blank.

[0008] Preferably, the metal parts are bolts and nuts, the bolt heads are located on the outer surface of the middle blank, the screw rod passes through the middle blank, and the nut is located on one side of the inner surface of the middle blank and is threadedly connected to the screw rod.

[0009] The method for preparing the above-mentioned peeling crack glaze ceramic comprises the following steps:

[0010] Step a, forming a blank, forming a through hole on the middle blank, and drying the blank;

[0011] Step b, carving annular indentations on the surfaces of the upper blank and the lower blank;

[0012] Step c, installing the metal part in the through hole;

[0013] Step d, covering the surface of the middle blank with a mask, applying black volcanic glaze on the upper blank and the middle blank, and removing the mask after drying;

[0014] Step e, covering the dried black volcanic glaze surface with a mask, applying a peeling glaze on the middle blank, and removing the mask after drying;

[0015] Step f, glaze firing in a kiln at a temperature of 1150-1200 degrees Celsius for 1-1.5 hours, then cooling to 800 degrees Celsius within 1-1.5 hours, and keeping warm for 3-4 hours in a reducing atmosphere, and continuing to maintain the reducing atmosphere and cooling naturally;

[0016] Step g: peeling off the peeling glaze from the middle blank by using a tool to expose the middle blank and the black cracks on its surface.

[0017] Preferably, in step c, the screw portion of the bolt is dipped in bonding slurry, the screw passes through the through hole of the middle blank, and the end of the screw is locked and connected with a nut. The raw materials of the bonding slurry include the following components in parts by weight: 20-30 parts of clay, 10-15 parts of sodium silicate, 20-30 parts of quartz powder, 25-35 parts of alumina powder, 20-25 parts of feldspar powder, 3-5 parts of sodium tripolyphosphate, and 10-15 parts of starch.

[0018] Preferably, in step e, the raw materials of the stripping glaze include the following components in parts by weight: 30-35 parts of quartz, 20-25 parts of feldspar, 10-15 parts of kaolin, 5-0 parts of talc, 3-6 parts of lithium carbonate, 5-8 parts of zinc oxide, 3-5 parts of borax, and 2-4 parts of aluminum oxide.

[0019] Preferably, in step e, before applying the stripping glaze, the head of the metal part is covered with solid wax.

[0020] Preferably, in step g, a tool is used to peel the stripping glaze, and the tool head applies pressure to the connection between the head of the metal part and the stripping glaze, forcing the stripping glaze to be peeled off from the middle blank, exposing the middle blank and cracks.

[0021] From the above description, it can be seen that the peeling crack glaze ceramics and the preparation method thereof provided by the present invention have the following beneficial effects: when the glaze is fired, the upper and lower blanks are covered with black volcanic glaze, and the middle blank is covered with peeling glaze. When the glaze is fired and cooled, the peeling glaze cracks due to the lower expansion coefficient of the blank, and drives the formation of cracks on the surface of the middle blank. The peeling glaze is then peeled off to expose the white middle blank with black cracks distributed on it, while the surfaces of the upper and lower blanks are covered with black volcanic glaze. The annular indentations of the upper and lower blanks can release stress, so that the black volcanic glaze is not easy to crack. The ceramic product manufactured is covered with black glaze on the upper and lower parts as a whole, and the middle part is a white blank without glaze and with black cracks, which has a strong sense of contrast and a unique artistic effect as a whole. DETAILED DESCRIPTION

[0022] The present invention is further described below through specific implementation modes.

[0023] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0024] The peeling crack glaze ceramic of the present invention comprises a body, which comprises an upper body, a middle body and a lower body from top to bottom in sequence, the upper body and the lower body are covered with black volcanic glaze, and cracks are distributed on the surface of the middle body. When the glaze is fired, the upper body and the lower body are covered with black volcanic glaze, and the middle body is covered with peeling glaze. When the glaze is fired and cooled, the peeling glaze cracks due to the lower expansion coefficient of the body, and drives the surface of the middle body to form cracks. After that, the peeling glaze is peeled to expose the white middle body with black cracks distributed thereon, and the surfaces of the upper body and the lower body are covered with black volcanic glaze. The annular indentations of the upper body and the lower body can release stress, so that the black volcanic glaze is not easy to crack. The ceramic product is covered with black glaze from top to bottom as a whole, and the middle part is a white body without glaze and with black cracks, which has a strong sense of contrast and a unique artistic effect as a whole.

[0025] The raw materials of the blank include the following components in parts by weight: 30-40 parts of kaolin, 20-30 parts of burnt clay, 20-25 parts of feldspar powder, 10-15 parts of quartz powder, 5-8 parts of borax, 10-13 parts of lead white, 5-8 parts of soda ash, 7-9 parts of cassiterite, and 6-8 parts of Suzhou soil. The blank is white without glaze, wherein cassiterite is added to the blank as an emulsifier, so that the blank is milky white, and the peeling glaze on the surface of the blank is peeled off, revealing the main body color of the blank, and black cracks generated by the peeling glaze are distributed on the blank.

[0026] There are annular indentations on the surface of the upper and lower blanks. The raw materials of the black volcanic glaze include the following components by weight: 4-6 parts of chromium oxide, 4-6 parts of iron oxide, 2-4 parts of nickel oxide, 20-25 parts of quartz, 35-40 parts of feldspar, 20-25 parts of kaolin, and 10-14 parts of calcium carbonate. The black volcanic glaze is dark black after firing. The annular indentations have the following functions: the cracking of the glaze surface is mainly due to the stress generated between the glaze layer and the blank during the firing and cooling process of the ceramic, which exceeds the bearing capacity of the glaze. The engraved annular lines will form certain undulations and gaps on the surface of the blank. When the glaze layer generates stress due to thermal expansion and contraction, these lines can buffer and disperse the stress. The annular lines provide a release channel for the stress, reducing the possibility of the glaze surface cracking due to stress concentration. The annular lines increase the surface area of ​​the body, allowing the glaze to adhere better and enhancing the mechanical bite between the glaze layer and the body. The stronger bonding force allows the glaze layer to more closely follow the changes of the body during contraction and expansion, reducing the glaze cracking caused by excessive relative displacement between the two. At the same time, the thermal expansion coefficients of the black volcanic glaze and the body are relatively close, so that the glaze and the body shrink and expand to similar degrees during heating and cooling. The thermal expansion coefficients of the black volcanic glaze and the peeling glaze are significantly different, resulting in the black volcanic glaze on the upper and lower bodies to adhere firmly and not crack, while the peeling glaze on the middle body has significant cracks.

[0027] Metal parts are embedded in the middle blank. The metal parts are embedded in the middle blank when the blank is formed. The material of the metal parts is iron, which has a high melting point. When fired at high temperature, except for a small part of the edge that melts, most of it can maintain its original shape. Its head is exposed on the surface of the middle blank, which plays a decorative role. The end face of the metal parts exceeds the surface of the blank by 2-3mm. At the same time, the end of the metal parts has another function. Since the shrinkage rate of the end of the metal parts and the material of the stripping glaze is different, during the cooling process, the end of the metal parts serves as the starting point for inducing cracks in the stripping glaze, and radial cracks are formed outward with the end of the metal parts as the center. When the glaze is fired, the carbon element penetrates into the middle blank along the radial cracks to form black radial cracks. When the stripping glaze is stripped, except for the black radial cracks, the rest of the middle blank is white as a whole, which has a unique artistic effect as a whole; at the same time, the end of the metal parts also serves as the starting point for stripping the stripping glaze. Tools are used to apply pressure and strip the glaze surface from the end of the metal parts to avoid damage to the middle blank during the pressure and stripping process.

[0028] The metal parts are bolts and nuts. The bolt head is located on the outer surface of the middle blank, the screw rod passes through the middle blank, and the nut is located on one side of the inner surface of the middle blank and is threadedly connected with the screw rod. The blank is a hollow structure, the bolt passes through the blank, and the other end is fixed by the nut. The metal parts are fixed to the blank through the structure of the bolt and nut.

[0029] The preparation method of peeling crack glaze ceramics comprises the following steps:

[0030] Step a, forming a blank, forming a through hole on the middle blank, and drying the blank;

[0031] Step b, carving annular indentations on the surfaces of the upper blank and the lower blank;

[0032] Step c, installing the metal part in the through hole;

[0033] Step d: Cover the surface of the middle blank with a mask, apply black volcanic glaze on the upper blank and the middle blank, and remove the mask after drying; the mask can be tape, paper, plastic film, etc., and its function is to protect the parts that do not need to be applied with glaze.

[0034] Step e: Cover the surface of the dried black volcanic glaze with a mask, apply a stripping glaze on the middle blank, and remove the mask after drying; by covering with the mask, the purpose of applying different glazes on the upper blank, the middle blank and the lower blank is achieved.

[0035] Step f, putting the glaze into the kiln for firing at a temperature of 1150-1200 degrees Celsius for 1-1.5 hours, then cooling to 800 degrees Celsius within 1-1.5 hours, and keeping warm for 3-4 hours in a reducing atmosphere, continuing to maintain the reducing atmosphere and cooling naturally; cooling to 800 degrees Celsius in a short period of time, because the expansion coefficient of the stripping glaze is lower than the expansion coefficient of the body, the stripping glaze cracks, and the cracking of the stripping glaze will induce cracks to form on the surface of the middle body, and then carbon powder is introduced into the kiln in a reducing atmosphere, and the carbon powder penetrates into the middle body and the cracks through the cracks, and the carbon element is absorbed by the cracks of the middle body. After the stripping glaze is subsequently stripped off, black cracks are formed.

[0036] Step g, using a tool to peel off the peeling glaze from the middle blank, exposing the middle blank and the black cracks on its surface. Since the expansion coefficients of the peeling glaze and the middle blank are greatly different, cracks will be generated in the peeling glaze during cooling, and the cracks are radially distributed with the metal piece as the center. There are multiple metal pieces spaced apart on the middle blank, and the cracks are interconnected to form a network. Moreover, since the bonding between the peeling glaze and the middle blank is very weak, the peeling glaze can be easily peeled off cleanly under the application of external force, exposing the inner blank.

[0037] In step c, the screw rod of the bolt is dipped into the bonding mud, the screw rod passes through the through hole of the middle blank, and the end of the screw rod is locked and connected with the nut. The raw materials of the bonding mud include the following components in parts by weight: 20-30 parts of clay, 10-15 parts of sodium silicate, 20-30 parts of quartz powder, 25-35 parts of alumina powder, 20-25 parts of feldspar powder, 3-5 parts of sodium tripolyphosphate, and 10-15 parts of starch. The bonding mud contains clay and sodium silicate as a binder, which is used to fill the gap between the screw rod and the blank. After drying, the metal parts are fixed on the blank, and starch is added to the raw materials of the bonding mud as a pore-forming agent to increase the porosity of the bonding mud, absorb the deformation of the blank, and prevent the blank from cracking at the junction with the metal.

[0038] In step e, the raw materials of the stripping glaze include the following components by weight: 30-35 parts of quartz, 20-25 parts of feldspar, 10-15 parts of kaolin, 5-0 parts of talc, 3-6 parts of lithium carbonate, 5-8 parts of zinc oxide, 3-5 parts of borax, and 2-4 parts of aluminum oxide. Quartz is used as the main raw material to provide silicon dioxide. High content of quartz can reduce the expansion coefficient. The proportion of feldspar is relatively high, so that the thermal expansion coefficient of the glaze surface is greatly different from that of the body, and the contraction of the cooling chamber is inconsistent, which causes cracking. Excessive talc affects the thermal stability of the glaze surface, resulting in easier cracking when the temperature changes. Too high a content of lithium carbonate will cause the glaze surface to shrink too fast during the cooling process, generating large internal stress, thereby causing cracking. Zinc oxide causes the thermal expansion coefficient of the glaze surface to not match that of the body, causing cracking. In summary, the components and formula of the stripping glaze make it not match the thermal expansion coefficient of the body, which can cause cracking during cooling.

[0039] In step e, before applying the stripping glaze, the head of the metal part is covered with solid wax. After the wax is heated and melted, the wax liquid is applied to the end surface of the metal part with a brush to form a wax protective film. The wax layer can effectively prevent the glaze from adhering. After the stripping glaze is applied and the glaze is dried, the blank is heated to melt the wax on the metal part and fall off, exposing the end of the metal part. The role of the solid wax is to cover the head of the metal part. Since the solid wax is hydrophobic, when the stripping glaze is applied, the stripping glaze will not cover the solid wax, so the stripping glaze will only cover the middle blank outside the metal part.

[0040] In step g, a tool is used to peel off the peeling glaze, and the tool head applies pressure to the connection between the head of the metal piece and the peeling glaze, forcing the peeling glaze to peel off from the middle blank, exposing the middle blank and cracks. The end of the metal piece is used as the starting point for peeling off the peeling glaze, and a tool is used to apply pressure and peel off the glaze surface from the end of the metal piece to avoid damage to the middle blank during the pressure and peeling process. The flaky peeling glaze is peeled off piece by piece from the end of the metal piece, and the peeling glaze on the middle blank is gradually peeled off, exposing the entire middle blank and the black cracks on the middle blank.

[0041] The above are only some specific implementation methods of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial changes to the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. Peeling crack glaze ceramics, characterized by: The invention comprises a body, which comprises an upper body, a middle body and a lower body from top to bottom in sequence, the upper body and the lower body are covered with black volcanic glaze, and cracks are distributed on the surface of the middle body.

2. The peeling crack glaze ceramic according to claim 1, characterized in that: The raw materials of the green body include the following components in parts by weight: 30-40 parts of kaolin, 20-30 parts of calcined clay, 20-25 parts of feldspar powder, 10-15 parts of quartz powder, 5-8 parts of borax, 10-13 parts of lead white, 5-8 parts of soda ash, 7-9 parts of cassiterite, and 6-8 parts of Suzhou soil.

3. The peeling crack glaze ceramic according to claim 1, characterized in that: Annular indentations are distributed on the surfaces of the upper and lower blanks. The raw materials of the black volcanic glaze include the following components in parts by weight: 4-6 parts of chromium oxide, 4-6 parts of iron oxide, 2-4 parts of nickel oxide, 20-25 parts of quartz, 35-40 parts of feldspar, 20-25 parts of kaolin, and 10-14 parts of calcium carbonate.

4. The peeling crack glaze ceramic according to claim 1, characterized in that: A metal piece is embedded in the middle blank.

5. The peeling crack glaze ceramic according to claim 1, characterized in that: The metal parts are bolts and nuts, the bolt heads are located on the outer surface of the middle blank, the screw rod passes through the middle blank, and the nuts are located on one side of the inner surface of the middle blank and are threadedly connected with the screw rod.

6. The method for preparing the peeling crack glaze ceramic according to any one of claims 1 to 5, characterized in that: The steps include: Step a, forming a blank, forming a through hole on the middle blank, and drying the blank; Step b, carving annular indentations on the surfaces of the upper blank and the lower blank; Step c, installing the metal part in the through hole; Step d, covering the surface of the middle blank with a mask, applying black volcanic glaze on the upper blank and the middle blank, and removing the mask after drying; Step e, covering the dried black volcanic glaze surface with a mask, applying a peeling glaze on the middle blank, and removing the mask after drying; Step f, glaze firing in a kiln at a temperature of 1150-1200 degrees Celsius for 1-1.5 hours, then cooling to 800 degrees Celsius within 1-1.5 hours, and keeping warm for 3-4 hours in a reducing atmosphere, and continuing to maintain the reducing atmosphere and cooling naturally; Step g: peeling off the peeling glaze from the middle blank by using a tool to expose the middle blank and the black cracks on its surface.

7. The method for preparing peeling crack glaze ceramics according to claim 6, characterized in that: In the step c, the screw rod portion of the bolt is dipped into the bonding slurry, the screw rod passes through the through hole of the middle blank, and the end of the screw rod is locked and connected with the nut. The raw materials of the bonding slurry include the following components in parts by weight: 20-30 parts of clay, 10-15 parts of sodium silicate, 20-30 parts of quartz powder, 25-35 parts of alumina powder, 20-25 parts of feldspar powder, 3-5 parts of sodium tripolyphosphate, and 10-15 parts of starch.

8. The method for preparing peeling crack glaze ceramics according to claim 6, characterized in that: In the step e, the raw materials of the stripping glaze include the following components in parts by weight: 30-35 parts of quartz, 20-25 parts of feldspar, 10-15 parts of kaolin, 5-0 parts of talc, 3-6 parts of lithium carbonate, 5-8 parts of zinc oxide, 3-5 parts of borax, and 2-4 parts of aluminum oxide.

9. The method for preparing peeling crack glaze ceramics according to claim 6, characterized in that: In the step e, before applying the stripping glaze, the head of the metal piece is covered with solid wax.

10. The method for preparing peeling crack glaze ceramics according to claim 6, characterized in that: In the step g, a tool is used to peel the stripping glaze, and the tool head applies pressure to the connection between the head of the metal part and the stripping glaze, forcing the stripping glaze to be peeled off from the middle blank, exposing the middle blank and cracks.