A mud for improving thermal shock resistance of Jian-shui purple pottery and a preparation method thereof

Abstract

The present application relates to the field of pottery clay. The purpose is to provide a kind of mud that can improve the thermal shock resistance of Jian Shui purple pottery, which is composed of main material and water. The main material is composed of the following raw materials in percentage by weight: 50% purple pottery clay, 20% cordierite, 15% talc, 10% purple pottery clay chamotte, and 5% silicon powder. The present application uses a reasonable proportion of purple pottery clay, cordierite, talc, purple pottery clay chamotte, and silicon powder to form the main material of the mud. By adding cordierite to the mud of Jian Shui purple pottery, the overall thermal expansion coefficient of the mud can be effectively reduced, and the thermal conductivity of the mud can be improved. This allows the temperature difference between the inside and outside of the material to be alleviated and balanced. When the temperature changes rapidly, the internal stress of the pottery product caused by thermal expansion and contraction is smaller, and the heat can be quickly transferred when heated, reducing the accumulation of thermal stress in the material in a short period of time. Therefore, thermal shock damage phenomena such as cracking and peeling are less likely to occur.

Description

TECHNICAL FIELD

[0001] The application relates to the field of clay materials, in particular to a clay material for improving the thermal shock resistance of Jian Shui purple pottery and a preparation method. BACKGROUND

[0002] Jian Shui purple pottery is a traditional folk handicraft in Jian Shui County, Yunnan Province, and is one of the four famous Chinese pottery, together with Jiangsu Yixing purple clay pottery, Guangxi Qinzhou Nixing pottery and Chongqing Rongchang pottery. The Jian Shui purple pottery has a long history, and is pure and clean, rich in various minerals and trace elements. The Jian Shui purple pottery is prepared through a plurality of complex processes including clay material preparation, blanking, wet blank decoration, carving and filling, high-temperature sintering and glaze-free polishing. The finished Jian Shui purple pottery has a fine texture and a breathable structure, and is widely praised in the tea and kitchen utensil industries.

[0003] However, due to the fine clay material, the particle size of the blank is between 180 and 400 meshes, the fine clay particles are small and have a large specific surface area, and a dense structure is more likely to be formed in the sintering process. Although this can make the ceramic have a smoother appearance and more uniform texture, it also leads to a decrease in the porosity and a decrease in the size of the pores in the ceramic. When the ceramic is subjected to a sharp change in temperature, the heat is transferred relatively quickly in the dense structure, and a large thermal stress is easily generated between different parts. However, due to the low porosity and small size of the pores, the thermal stress cannot be effectively relieved, so the ceramic is more likely to crack or even break, and the thermal shock resistance is reduced. Therefore, it is a very important problem in the Jian Shui purple pottery industry to improve the thermal shock resistance of the product without affecting the plasticity and overall fine texture of the clay material, by improving the material ratio and process of the clay material. SUMMARY

[0004] The application aims to provide a clay material for improving the thermal shock resistance of Jian Shui purple pottery and a preparation method. The clay material has good plasticity, has no obvious effect on molding, has excellent thermal shock resistance, can be cooked by open fire, and has the advantages of fine texture and good breathability of Jian Shui purple pottery clay.

[0005] To achieve the above-mentioned application purposes, the technical solution adopted by the application is as follows: a clay material for improving the thermal shock resistance of Jian Shui purple pottery is formed by mixing and stirring a main material and water, and the main material is composed of the following raw materials in the following weight percentages: 50% of purple pottery clay, 20% of staurolite, 15% of talc, 10% of purple pottery clay chamotte, and 5% of silicon powder.

[0006] Preferably, the purple pottery clay is composed of the following raw materials in the following weight percentages: 50% of wuhua clay, 15% of loess, 15% of white clay, 10% of gray clay, and 10% of purple clay.

[0007] Preferably, the weight ratio of the main material to water is 1:0.8.

[0008] Preferably, the particle size of each raw material in the main material is 250 mesh for purple clay, 200 mesh for cordierite, 300 mesh for talc, 200 mesh for purple clay grog, and 400 mesh for silica powder.

[0009] Preferably, in the preparation method of the mud, the main material and water are mixed at a ratio of 1:0.8, stirred sufficiently to make them uniformly mixed, and screened through a 200-mesh sieve to remove impurities; the mud cake is obtained by pressure filtration through a filter press, and the mud cake is sent to a mud mill for mud preparation to obtain a green body with a water content of 20-25%.

[0010] Preferably, the mud is milled three times by the mud mill, and the extrusion pressure of the discharge port of the mud mill is controlled during the milling process. The extrusion pressure of the discharge port of the mud mill is pressurized in the first two times of milling, and gradually reduced in the two times. The extrusion pressure of the discharge port of the mud mill returns to normal in the third time of milling.

[0011] Preferably, the extrusion pressure of the discharge port of the mud mill is controlled by an outlet pressure adjusting device arranged between the extrusion cylinder and the discharge cylinder of the mud mill; the outlet pressure adjusting device comprises a connecting cylinder and a pressurizing cylinder arranged on the upper part of the connecting cylinder, the two ends of the connecting cylinder are respectively communicated with the extrusion cylinder and the discharge cylinder, and the pressurizing cylinder is communicated with the connecting cylinder; a mud pressing plate capable of moving vertically in the pressurizing cylinder is arranged in the pressurizing cylinder, and the mud pressing plate is driven by a driving mechanism.

[0012] Preferably, the connecting cylinder comprises an inner cylinder and an outer cylinder, an annular cavity is formed between the inner cylinder and the outer cylinder, and the annular cavity is communicated with the pressurizing cylinder; a plurality of strip-shaped holes extending along the length direction of the inner cylinder are uniformly arranged on the side wall of the inner cylinder in a ring shape, and the annular cavity is communicated with the inner cylinder through the strip-shaped holes.

[0013] Preferably, a pressurizing nozzle is arranged on the inner side wall of the inner cylinder corresponding to the strip-shaped hole, the pressurizing nozzle extends along the length direction of the strip-shaped hole, and the inner cavity of the pressurizing nozzle gradually narrows from outside to inside.

[0014] Preferably, the driving mechanism comprises a screw rod arranged in the upper section of the pressurizing cylinder, the upper end of the screw rod is connected with a driving motor arranged on the top of the pressurizing cylinder; a driving sleeve is arranged outside the screw rod, the driving sleeve is threadedly matched with the screw rod, and the driving sleeve is fixedly connected with the mud pressing plate through a crank arm.

[0015] Preferably, the driving sleeve comprises a main sleeve threadedly matched with the screw rod and arranged outside the screw rod, and a secondary sleeve rotationally matched with the main sleeve and arranged outside the lower end of the main sleeve, the secondary sleeve is connected with the crank arm;

[0016] A plurality of column holes extending along the radial direction of the secondary sleeve are uniformly arranged on the inner side wall of the secondary sleeve in a ring shape, and a pin column with hemispherical ends is arranged in the column hole; a hemispherical clamping groove is arranged on the outer side wall of the main sleeve opposite to the pin column;

[0017] The top of the secondary sleeve is provided with an annular groove extending downward from the upper end face, and the annular groove is closed by a cover plate provided on the top of the secondary sleeve. A vertical adjusting bolt is provided on the cover plate opposite to the annular groove, and the adjusting bolt is threaded into the cover plate. A pressure ring and a set of butterfly springs are arranged sequentially from top to bottom in the annular groove. A pressure ring is also provided below the butterfly springs at a position corresponding to the pin. The adjusting bolt presses the outer end of the pin by squeezing the pressure ring, butterfly springs and pressure ring, and causes the pin to extend into the groove on the main sleeve.

[0018] Preferably, an air inlet is provided on one side of the upper part of the pressure cylinder, which communicates with the inside of the pressure cylinder, and the air inlet is connected to the exhaust port of the vacuum device of the pumice machine through a pipeline.

[0019] Preferably, the connecting cylinder is provided with flanges at both ends, and is connected to the extrusion cylinder and the discharge cylinder through the flanges.

[0020] Preferably, the connecting cylinder has a stepped surface at one end near the extrusion cylinder that corresponds to the inner cavity of the extrusion cylinder, and a sealing ring with a triangular cross-section is provided on the stepped surface.

[0021] The beneficial effects of this invention are mainly reflected in the following aspects: The main material of the clay is composed of a reasonable ratio of purple clay, cordierite, talc, purple clay clinker, and silica powder. By adding cordierite to the clay of Jianshui purple pottery, this invention effectively reduces the overall thermal expansion coefficient of the clay and improves its thermal conductivity. This alleviates and balances the temperature difference between the inside and outside of the material. When the temperature changes rapidly, the internal stress generated by thermal expansion and contraction in the pottery is smaller, allowing for rapid heat transfer and reducing the accumulation of thermal stress in the material within a short period. This makes it less prone to thermal shock damage such as cracking and peeling. Simultaneously, cordierite, through its crystal structure and distribution, can also hinder crack propagation and consume the energy required for crack propagation, thereby improving the thermal shock resistance of the finished product. Furthermore, this clay has good plasticity and does not significantly affect molding. While maintaining good thermal shock resistance, it also possesses the advantages of fine texture and good breathability of Jianshui purple pottery clay. Attached Figure Description

[0022] Figure 1 This is a flowchart of the process flow of the present invention;

[0023] Figure 2 This is a schematic diagram of the discharge port of an existing plywood mill.

[0024] Figure 3 This is a schematic diagram of the outlet pressure regulating device used in this invention;

[0025] Figure 4 for Figure 3 Enlarged view of part A;

[0026] Figure 5Schematic view of the end structure of the pressurizing nozzle. DETAILED DESCRIPTION

[0027] The application is a kind of mud for improving the thermal shock resistance of Jian Shui purple pottery and its preparation method. The mud is mainly used for the production of Jian Shui purple pottery products such as tea sets and kitchen utensils. It has the advantages of fine texture, good air permeability, good thermal shock resistance, and is not easy to crack when heated. It can be cooked with open fire.

[0028] The application adds cordierite to the mud of Jian Shui purple pottery, which can effectively reduce the overall thermal expansion coefficient of the mud and improve the thermal conductivity of the mud. This allows the temperature difference between the inside and outside of the material to be relieved and balanced. When the temperature changes sharply, the internal stress of the ceramic product caused by thermal expansion and cold contraction is small. When heated, it can quickly transfer heat and reduce the accumulation of thermal stress of the material in a short period of time. Thus, it is not easy to appear cracking, peeling and other thermal shock damage phenomena. At the same time, cordierite can also hinder crack propagation through its crystal structure and distribution, consume the energy of crack propagation, thereby improving the thermal shock resistance of the finished product.

[0029] Purple pottery clay grog is a powder obtained by grinding purple pottery clay after sintering at a specific temperature. The sintering temperature is generally 1100-1250℃. When making Jian Shui purple pottery with high thermal shock resistance, purple pottery clay grog will be used. After mixing these grog powders in a reasonable proportion, the plasticity of the blank is reduced to a certain extent, the shrinkage of the blank is reduced, which is beneficial to overcome the deformation and cracking of the product, and also improves the thermal stability and mechanical strength.

[0030] The application will be described in detail below in conjunction with the embodiments.

[0031] Embodiment 1

[0032] A kind of mud for improving the thermal shock resistance of Jian Shui purple pottery, formula is formed by main material and water mixing stirring, the main material is formed by the following weight percentage of raw materials: 250 mesh purple pottery clay 50%, 200 mesh cordierite 20%, talc 15%, 300 mesh purple pottery clay grog 10%, 400 mesh silicon powder 5%; The purple pottery clay is formed by the following weight percentage of raw materials: five flower soil 50%, loess 15%, white clay 15%, grey soil 10%, purple soil 10%, each soil is passed through 250 mesh screen, and then mixed uniformly according to the proportion to form purple pottery clay.

[0033] As Figure 1The total preparation process of the clay body according to the present application is as follows: the main material and water are mixed in a ratio of 1:0.8, and stirred thoroughly to make them uniformly mixed, and then screened through a 200-mesh sieve to remove impurities; the clay cake is obtained by pressure filtration through a filter press, and then sent to a clay mill for clay milling, and the clay milling is performed three times to prepare a green body with a water content of 20-25%. The clay mill is a ZL-350 vacuum clay mill produced by Hekou City Helong Special Equipment Co., Ltd. When the above clay body is extruded, the extrusion pressure of the discharge port is measured to be 1.3 MPa.

[0034] Example 2

[0035] The same as example 1, except that: in the clay milling, the clay milling is performed three times by the clay mill, and the extrusion pressure of the discharge port of the clay mill is controlled during the clay milling process, and the extrusion pressure of the discharge port of the clay mill is gradually reduced in the first two times of clay milling, and no pressure treatment is performed in the third time, and the discharge port pressure returns to the normal level. The first and second times of pressure treatment are 1.8 MPa and 1.5 MPa, respectively, and the third time is 1.3 MPa.

[0036] Comparative Example 1

[0037] The same as the preparation method of example 1, except that: the cordierite is 15%, and the purple pottery clay chamotte is 15%.

[0038] Comparative Example 2

[0039] The same as the preparation method of example 1, except that: the cordierite is 25%, and the purple pottery clay chamotte is 5%.

[0040] Comparative Example 3

[0041] The same as the preparation method of example 1, except that: the main material formula: purple pottery clay 65%, talc 15%, purple pottery clay chamotte 15%, and silicon powder 5%.

[0042] Comparative Example 4

[0043] The same as the preparation method of example 1, except that: the main material formula: purple pottery clay 65%, cordierite 15%, talc 15%, and silicon powder 5%.

[0044] Plasticity test: the plasticity of the clay bodies prepared in examples 1-2 and comparative examples 1-4 is analyzed, and during the analysis, a round rod sample with a diameter of 2 cm and a length of 20 cm is cut from the clay body through a sampling tube; hold both ends of the sample and perform a back-and-forth loop bending, and score the plasticity according to the fracture and surface crack conditions, and more than 10 times of back-and-forth bending without fracture or crack is excellent, 5-10 times of back-and-forth bending without fracture or crack is qualified, and less than 5 times of back-and-forth bending with fracture or crack is unqualified (poor plasticity), and the results are shown in Table 1 below;

[0045] Porosity test: The clay of example 1-2, comparative example 1-4 was shaped into 20cm in diameter, 1.5cm in wall thickness sand pots by traditional process, and sintered into 10 pots each. The porosity of example 1-2, comparative example 1-4 was tested. First, the 10 samples were weighed in air, then they were completely immersed in water, so that the pores were filled with water. The surface water was wiped dry with a dry towel, and weighed again. According to the data of the two weighings and the density of water, the volume of water, i.e. the pore volume, was calculated, and finally the porosity was calculated. The average porosity of the 10 samples in each example or comparative example was taken as the final data (retained to one decimal place), and the results are shown in Table 1 below.

[0046] Thermal shock resistance test: The sand pot samples of example 1-2, comparative example 1-4 after the porosity test were subjected to thermal shock resistance test. During the test, each sand pot sample was heated at 1300℃ for 5 minutes, and then cooled in water at a temperature lower than 5℃ for 1 minute. The above process was repeated until the sand pot cracked or broke, which was recorded as damage. The number of cycles before damage was recorded, and the average number of thermal shock cycles of the 10 samples in each example or comparative example was taken as the final data (retained to the integer), and the results are shown in Table 1 below.

[0047] Good product rate test: 100 ceramic cups with a diameter of 5cm were made from the clay of example 1-2 by traditional process of clay shaping and sintering. The flaws of the 100 ceramic cups of example 1 and example 2 were judged, and the good product rate was calculated. The results are shown in Table 1 below.

[0048] Table 1: Plasticity and thermal shock resistance of the clay in the examples and comparative examples

[0049]

[0050] As can be seen from Table 1, the clay according to the present application has good plasticity and does not significantly affect shaping. It has the advantages of fine texture and good air permeability of Jiashui Zitao clay, and has a great improvement in thermal shock resistance.

[0051] After three times of clay refining by a clay refining machine and controlling the pressure, the thermal shock resistance is further improved, and the good product rate of the product is excellent. The inventor believes that the reason is as follows: Jiashui Zitao clay has fine and tight texture. During the refining process, the air inside the clay body is more difficult to be discharged. Therefore, the clay body needs to be refined multiple times by a vacuum clay refining machine, otherwise it is easy to have hole defects in the clay body, which affects the quality of the finished product. By increasing the extrusion pressure at the discharge port of the clay refining machine and refining multiple times, the density of the clay body is better, which helps to discharge the gas inside the clay body and reduce the internal hole defects.

[0052] The present application adopts three times of mud mixing, and the first two times of mud mixing are under pressure, which can assist the discharge of gas in the mud, improve the density, eliminate the possible hole defects in the later stage, and on the other hand, the normal discharge port pressure of the mud mixing machine is used in the last time of mud mixing, since the mud is extruded under pressure and then enters the mud mixing machine again and is broken and transported by the twisting teeth, although there is a risk of generating holes again, the mud is protected by the vacuum system during the mud mixing process, and the influence is not significant; instead, the normal pressure treatment can restore the overpressure defects caused by the pressure, and the plasticity and uniformity of the mud are restored, and the risk of uneven particles is reduced. The reasonable and effective processing procedure of the present application can well ensure the final good yield rate of the finished product.

[0053] Of course, when controlling the pressure of the discharge port, theoretically, although the size of the discharge port can be reduced to significantly improve the extrusion pressure and reduce the hole defects in the green body, this method is not universal due to the size requirements of the green body for the drawing molding, and frequent replacement of the discharge port also increases the complexity of the operation. Increasing the rotation speed of the main shaft to increase the pressure will increase the output power of the main motor, which may cause the motor to burn out, and replacing the high-power new equipment to meet the demand for increasing the extrusion pressure will obviously cause a huge economic burden to the enterprise, which is not desirable. Therefore, how to modify the existing mud mixing machine to achieve the effect of increasing the pressure is also a very important problem, and therefore, the present application also discloses a mud mixing machine outlet pressure adjusting device suitable for modification of the existing machine type and capable of effectively controlling the pressure of the discharge port.

[0054] The existing mud mixing machine outlet is shown in Figure 2 , which is a direct flange connection between the extrusion cylinder 3 and the discharge cylinder 4. The pressure adjusting device of the present application is shown in Figures 3-5 , which includes a connecting cylinder 1 and a pressurizing cylinder 2 arranged on the upper part of the connecting cylinder 1, which is installed between the extrusion cylinder 3 and the discharge cylinder 4, and can meet the installation requirements of various types. The two ends of the connecting cylinder 1 are in communication with the extrusion cylinder 3 and the discharge cylinder 4, respectively, and the pressurizing cylinder 2 is in communication with the connecting cylinder 1. The connection between the connecting cylinder 1 and the extrusion cylinder 3 and the discharge cylinder 4 is also a direct flange connection, that is, the two ends of the connecting cylinder 1 are provided with flanges, and the flanges are connected with the extrusion cylinder 3 and the discharge cylinder 4. In order to ensure the tightness of the connection, a sealing gasket can be added between the two flanges, and in order to facilitate the mud in the extrusion cylinder 3 to enter the connecting cylinder 1, a stepped surface corresponding to the inner cavity of the extrusion cylinder 3 is formed on the end of the connecting cylinder 1 close to the extrusion cylinder 3, and a sealing ring 27 with a triangular cross section is arranged on the stepped surface.

[0055] The pressing cylinder 2 is provided with a pressing plate 5 capable of moving along the vertical direction of the pressing cylinder 2, which is driven by a driving mechanism. The specific structure of the driving mechanism is more, and simply from the point of view of implementation, it can be, for example: hydraulic cylinder (simple control, but relatively expensive), air cylinder (simple control, but relatively poor extrusion pressure, need special customization, and the pressure is not stable enough).

[0056] At the beginning of use, first use the plug to block the discharge port of the discharge cylinder 4. After the clay machine spindle extrudes and fills the lower section of the discharge cylinder 4, the connecting cylinder 1 and the pressing cylinder 2, open the plug, and normally discharge. The pressure sensor arranged in the discharge cylinder 4 detects the pressure of the discharge port. When the pressure is increased, the driving mechanism controls the pressing plate 5 to press down, and the clay machine spindle extrudes the clay together, so as to test the purpose of the pressure. This form of pressure regulating device is convenient for the modification of the existing equipment to control the discharge port pressure, and will not significantly increase the economic burden of enterprises.

[0057] In order to make the pressure from the pressing plate 5 more evenly distributed to the clay at the connecting cylinder 1 and the discharge cylinder 4, the connecting cylinder 1 can include an inner cylinder 6 and an outer cylinder 7, which are generally assembled by detachable connection, so as to facilitate disassembly and cleaning after use, and facilitate secondary use. The annular cavity 8 is formed between the inner cylinder 6 and the outer cylinder 7, and the annular cavity 8 is communicated with the pressing cylinder 2; a plurality of strip-shaped holes 9 extending along the length direction of the inner cylinder 6 are uniformly arranged on the side wall of the inner cylinder 6 in a ring shape, and the annular cavity 8 is communicated with the inner cylinder 6 through the strip-shaped hole 9. In this way, the clay can be extruded from the circumference to the inside through the annularly distributed strip-shaped holes 9, and the overall extrusion uniformity is better. Generally, 4-6 strip-shaped holes 9 can be arranged, and too many are not conducive to the overall structural strength of the inner cylinder 6.

[0058] In an alternative, for some low viscosity materials with relatively large fluidity, in order to improve the extrusion pressure, prevent the clay from backflowing to the annular cavity 8 and the pressing cylinder 2, and reduce the load of the pressing plate 5, in combination with the description in Figure 3 and 5 A pressing nozzle 10 is arranged on the inner side wall of the inner cylinder 6 corresponding to the strip-shaped hole 9, the pressing nozzle 10 extends along the length direction of the strip-shaped hole 9, and the inner cavity of the pressing nozzle 10 gradually narrows from outside to inside.

[0059] Regarding the specific form of the driving mechanism, a feasible scheme is as follows Figure 3As shown, the driving mechanism of the present invention includes a screw 11 disposed in the upper section of the pressure cylinder 2. The upper end of the screw 11 is connected to a drive motor 12 disposed at the top of the pressure cylinder 2. A drive sleeve 13 is sleeved on the screw 11, and the drive sleeve 13 is threadedly engaged with the screw 11. The drive sleeve 13 is fixedly connected to the pressing plate 5 via a crank arm 14. The drive motor 12 continuously outputs power to the screw 11, and the screw 11 drives the pressing plate 5 downward through the drive sleeve 13 and the crank arm 14. At this time, the pressure cylinder 2 is generally a square cylinder, and the pressing plate 5 is a square plate that slides with it. However, in this case, in order to control the pressure and simultaneously provide pressure limiting protection for the drive motor 12, the drive sleeve 13 of the present invention can disengage the power when the pressure exceeds the set pressure, and can also connect the power when the pressure is insufficient, driving the pressing plate 5 to continue to press down.

[0060] Therefore, such as Figure 4 As shown, the drive sleeve 13 includes a main sleeve 15 that is sleeved on the outside of the screw 11 and has a threaded engagement with the screw 11, and a secondary sleeve 16 that is sleeved on the lower end of the main sleeve 15 and has a rotatable engagement with the main sleeve 15. The secondary sleeve 16 is connected to the crank arm 14.

[0061] The structure for achieving power connection and power release is as follows: A plurality of circularly arranged post holes 17 extending radially along the inner wall of the secondary sleeve 16 are uniformly arranged on the inner sidewall; each post hole 17 contains a pin 18 with hemispherical ends; a hemispherical groove 19 is provided on the outer sidewall of the main sleeve 15 opposite to the pin 18; the top of the secondary sleeve 16 has an annular groove 20 extending downward from its upper end face, and the annular groove 20 is closed by a cover plate 21 located on the top of the secondary sleeve 16. A vertical adjusting bolt 22 is provided on the cover plate 21 at a position opposite to the annular groove 20. The adjusting bolt 22 is threadedly engaged with the cover plate 21. A pressure ring 23 and a set of butterfly spring pieces 24 are arranged sequentially from top to bottom in the annular groove 20. A pressure ring 25 is also provided below the butterfly spring pieces 24 at a position corresponding to the pin 18. The adjusting bolt 22 presses the outer end of the pin 18 by squeezing the pressure ring 23, the butterfly spring pieces 24 and the pressure ring 25, and causes the pin 18 to extend into the slot 19 on the main sleeve 15.

[0062] When the pressure is insufficient, the screw 11 continuously drives the drive sleeve 13, which in turn drives the mud-pressing plate 5 downwards via the crank arm 14. When the power reaches the set value (set via the adjusting bolt 22), the drive sleeve 13 cannot continue to move downwards due to the large reaction force. As the screw 11 continues to rotate, the rotational force of the main sleeve 15 overcomes the elastic force of the butterfly spring 24, pushing the pin 18 back from the slot 19 into the pin hole 17, thus disengaging the main sleeve 15 and the auxiliary sleeve 16, achieving power release. When pressure adjustment is required, the side door on the upper section of the pressure cylinder 2 can be opened, and the adjusting bolt 22 can be turned.

[0063] On this basis, in order to further improve the performance of the pressurizing adjusting device, one side of the upper part of the pressurizing cylinder 2 is provided with an air inlet nozzle 26 communicated with the inside of the pressurizing cylinder 2, and the air inlet nozzle 26 is communicated with the exhaust port of the vacuum device of the mud mixing machine through a pipeline. The air inlet nozzle 26 can be connected to the exhaust port of the vacuum device, and the pressurized air punched by the vacuum device is used to pressurize the inside of the pressurizing cylinder 2, so as to improve the internal pressure of the pressurizing cylinder 2, thereby reducing the load of the driving motor 12 and the load of the mud pressing plate 5 to a certain extent.

Claims

1. A clay material for improving the thermal shock resistance of Jianshui purple pottery, characterized in that, It is composed of a main ingredient and water, wherein the main ingredient consists of the following raw materials in weight percentage: 50% kaolin, 20% cordierite, 15% talc, 10% kaolin clinker, and 5% silica powder; The purple clay is composed of the following raw materials by weight percentage: 50% multicolored clay, 15% yellow clay, 15% white clay, 10% gray clay, and 10% purple clay; The weight ratio of the main ingredient to water is 1:0.8; The particle sizes of the raw materials in the main ingredients are: 250 mesh for purple clay, 200 mesh for cordierite, 300 mesh for talc, 200 mesh for purple clay clinker, and 400 mesh for silica powder. The preparation method of the mud is as follows: Mix the main material and water at a ratio of 1:0.8, stir thoroughly to make the mixture uniform, and remove impurities by passing through a 200-mesh sieve; press the mud into mud cake by a filter press, and send the mud cake into a mud refining machine for refining to prepare a blank with a moisture content of 20-25%; The mud was processed three times in a mud-making machine. During the mud-making process, the extrusion pressure at the discharge port of the mud-making machine was controlled. In the first two mud-making processes, the extrusion pressure at the discharge port of the mud-making machine was increased and then gradually decreased. In the third mud-making process, the extrusion pressure at the discharge port of the mud-making machine returned to normal. The extrusion pressure at the discharge port of the pumice machine is controlled by an outlet pressure regulating device set between the extrusion cylinder (3) and the discharge port of the pumice machine. The outlet pressure regulating device includes a connecting cylinder (1) and a pressure cylinder (2) disposed on the upper part of the connecting cylinder (1). The two ends of the connecting cylinder (1) are respectively connected to the extrusion cylinder (3) and the discharge cylinder (4). The pressure cylinder (2) is connected to the connecting cylinder (1). A mud-pressing plate (5) capable of moving along the vertical direction of the pressure cylinder (2) is provided inside the pressure cylinder (2). The mud-pressing plate (5) is driven by a driving mechanism. The connecting cylinder (1) includes an inner cylinder (6) and an outer cylinder (7), and the inner cylinder (6) and the outer cylinder (7) form an annular cavity (8), which is connected to the pressure cylinder (2); the inner cylinder (6) has a plurality of strip holes (9) extending along the length of the inner cylinder (6) evenly arranged in an annular pattern on its side wall, and the annular cavity (8) is connected to the inner cylinder (6) through the strip holes (9); The drive mechanism includes a screw (11) disposed in the upper section of the pressure cylinder (2), the upper end of the screw (11) being connected to a drive motor (12) disposed at the top of the pressure cylinder (2); a drive sleeve (13) is provided on the screw (11), the drive sleeve (13) being threadedly engaged with the screw (11), and the drive sleeve (13) being fixedly connected to the mud plate (5) via a crank arm (14); The drive sleeve (13) includes a main sleeve (15) sleeved outside the screw (11) and forming a threaded engagement with the screw (11), and a secondary sleeve (16) sleeved outside the lower end of the main sleeve (15) and forming a rotational engagement with the main sleeve (15). The secondary sleeve (16) is connected to the crank arm (14). The inner wall of the sub-sleeve (16) is uniformly provided with a number of column holes (17) extending radially along the sub-sleeve (16) in a ring shape, and a pin (18) with hemispherical ends is provided in the column hole (17); a hemispherical groove (19) is provided on the outer wall of the main sleeve (15) opposite to the pin (18). The top of the sub-sleeve (16) is provided with an annular groove (20) extending downward from the upper end face, and the annular groove (20) is closed by a cover plate (21) provided on the top of the sub-sleeve (16). A vertical adjusting bolt (22) is provided on the cover plate (21) at a position opposite to the annular groove (20), and the adjusting bolt (22) is threadedly engaged with the cover plate (21). A pressure ring (23) and a set of butterfly spring pieces (24) are arranged sequentially from top to bottom in the annular groove (20). A pressure ring (25) is also provided below the butterfly spring pieces (24) at a position corresponding to the pin (18). The adjusting bolt (22) presses the outer end of the pin (18) by squeezing the pressure ring (23), the butterfly spring pieces (24) and the pressure ring (25), and causes the pin (18) to extend into the slot (19) on the main sleeve (15).

2. The method for preparing clay material to improve the thermal shock resistance of Jianshui purple pottery according to claim 1, characterized in that: Mix the main material and water at a ratio of 1:0.8, stir thoroughly to make the mixture uniform, and remove impurities by passing through a 200-mesh sieve; press the mixture into mud cakes using a filter press, and then send the mud cakes into a mud refining machine to refining the mud to prepare raw materials with a moisture content of 20-25%. The mud was processed three times in a mud-making machine. During the mud-making process, the extrusion pressure at the discharge port of the mud-making machine was controlled. In the first two mud-making processes, the extrusion pressure at the discharge port of the mud-making machine was increased and then gradually decreased. In the third mud-making process, the extrusion pressure at the discharge port of the mud-making machine returned to normal. The extrusion pressure at the discharge port of the pumice machine is controlled by an outlet pressure regulating device set between the extrusion cylinder (3) and the discharge port of the pumice machine. The outlet pressure regulating device includes a connecting cylinder (1) and a pressure cylinder (2) disposed on the upper part of the connecting cylinder (1). The two ends of the connecting cylinder (1) are respectively connected to the extrusion cylinder (3) and the discharge cylinder (4). The pressure cylinder (2) is connected to the connecting cylinder (1). A mud-pressing plate (5) capable of moving along the vertical direction of the pressure cylinder (2) is provided inside the pressure cylinder (2). The mud-pressing plate (5) is driven by a driving mechanism. The connecting cylinder (1) includes an inner cylinder (6) and an outer cylinder (7), and the inner cylinder (6) and the outer cylinder (7) form an annular cavity (8), which is connected to the pressure cylinder (2); the inner cylinder (6) has a plurality of strip holes (9) extending along the length of the inner cylinder (6) evenly arranged in an annular pattern on its side wall, and the annular cavity (8) is connected to the inner cylinder (6) through the strip holes (9); The drive mechanism includes a screw (11) disposed in the upper section of the pressure cylinder (2), the upper end of the screw (11) being connected to a drive motor (12) disposed at the top of the pressure cylinder (2); a drive sleeve (13) is provided on the screw (11), the drive sleeve (13) being threadedly engaged with the screw (11), and the drive sleeve (13) being fixedly connected to the mud plate (5) via a crank arm (14); The drive sleeve (13) includes a main sleeve (15) sleeved outside the screw (11) and forming a threaded engagement with the screw (11), and a secondary sleeve (16) sleeved outside the lower end of the main sleeve (15) and forming a rotational engagement with the main sleeve (15). The secondary sleeve (16) is connected to the crank arm (14). The inner wall of the sub-sleeve (16) is uniformly provided with a number of column holes (17) extending radially along the sub-sleeve (16) in a ring shape, and a pin (18) with hemispherical ends is provided in the column hole (17); a hemispherical groove (19) is provided on the outer wall of the main sleeve (15) opposite to the pin (18). The top of the sub-sleeve (16) is provided with an annular groove (20) extending downward from the upper end face, and the annular groove (20) is closed by a cover plate (21) provided on the top of the sub-sleeve (16). A vertical adjusting bolt (22) is provided on the cover plate (21) at a position opposite to the annular groove (20), and the adjusting bolt (22) is threadedly engaged with the cover plate (21). A pressure ring (23) and a set of butterfly spring pieces (24) are arranged sequentially from top to bottom in the annular groove (20). A pressure ring (25) is also provided below the butterfly spring pieces (24) at a position corresponding to the pin (18). The adjusting bolt (22) presses the outer end of the pin (18) by squeezing the pressure ring (23), the butterfly spring pieces (24) and the pressure ring (25), and causes the pin (18) to extend into the slot (19) on the main sleeve (15).

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