Mud for improving thermal shock resistance of Jianshui purple pottery and preparation method

Abstract

The invention relates to the field of clay materials. The invention aims to provide pug for improving thermal shock resistance of Jianshui purple pottery, the pug is formed by mixing and stirring a main material and water, and the main material is prepared from the following raw materials in percentage by weight: 50% of purple pottery clay, 20% of cordierite, 15% of talc, 10% of purple pottery clay clinker and 5% of silica powder. The purple pottery clay, the cordierite, the talc, the purple pottery clay clinker and the silica powder are reasonably proportioned to form a main material of the pug, and the cordierite is added into the pug of the Jianshui purple pottery, so that the overall thermal expansion coefficient of the pug can be effectively reduced, the thermal conductivity of the pug is improved, the temperature difference between the inside and the outside of the material is relieved and balanced, and when the temperature is sharply changed, the thermal conductivity of the pug is improved. The internal stress generated by thermal expansion and cold contraction of the ceramic product is small, heat can be quickly transferred when the ceramic product is heated, and thermal stress gathering of the material in a short time is reduced. Therefore, thermal shock damage phenomena such as cracking and peeling are not easy to occur.

Description

Technical Field

[0001] The invention relates to the field of pottery clay materials, and in particular to a clay material for improving the thermal shock resistance of Jianshui purple pottery and a preparation method thereof. Background Art

[0002] Jianshui purple pottery is a traditional folk craft from Jianshui County, Yunnan Province. It is considered one of China's "Four Famous Potteries," along with Yixing purple sand pottery from Jiangsu, Nixing pottery from Qinzhou, Guangxi, and Rongchang pottery from Chongqing. Its craftsmanship dates back a long time, and its fine texture is pure and free of impurities, rich in various minerals and trace elements. It is crafted through a complex production process involving clay preparation, wheel throwing, wet-body decoration, carving and filling, high-temperature firing, and unglazed polishing. The finished product, Jianshui purple pottery, boasts a delicate feel and breathable structure, earning it widespread acclaim in the teaware and kitchenware industries.

[0003] However, it is precisely because of its fine clay material, the general particle size of the blank is between 180 mesh and 400 mesh, the fine clay material has small particles and a large specific surface area, which makes it easier to form a dense structure during the sintering process. Although this can make the appearance of the ceramic smoother and the texture more uniform, it also leads to a decrease in its internal porosity and a smaller pore size. When the ceramic is subjected to a sharp change in temperature, due to the relatively fast heat transfer in the dense structure, large thermal stress is easily generated between different parts, and due to the low porosity and small size, the thermal stress cannot be effectively relieved, making the ceramic more prone to cracks or even rupture, reducing the thermal shock resistance. For this reason, how to improve the thermal shock resistance of the product by improving the material ratio of the clay and the process without affecting the plasticity and overall fine texture of the clay is a very important issue in the Jianshui purple pottery industry. Summary of the Invention

[0004] The object of the present invention is to provide a clay material and a preparation method for improving the thermal shock resistance of Jianshui purple pottery. The clay material has good plasticity, has no obvious effect on molding, has excellent thermal shock resistance, and can be cooked over an open fire; and also has the advantages of Jianshui purple pottery clay material of fine texture and good air permeability.

[0005] To achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is: a clay material for improving the thermal shock resistance of Jianshui purple pottery, which is composed of a main ingredient and water mixed and stirred, wherein the main ingredient is composed of the following raw materials in the following weight percentages: 50% purple clay, 20% cordierite, 15% talc, 10% purple clay clinker, and 5% silicon powder.

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

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

[0008] Preferably, the particle size of each raw material in the main ingredient is 250 mesh of kaolin, 200 mesh of cordierite, 300 mesh of talc, 200 mesh of kaolin clinker, and 400 mesh of silicon powder.

[0009] Preferably, the method for preparing the mud material is to mix the main material and water in a ratio of 1:0.8, stir them thoroughly to make them evenly mixed, and pass them through a 200-mesh sieve to remove impurities; filter them through a filter press to form a mud cake, and send the mud cake to a mud kneading machine for mud kneading to prepare a blank with a moisture content of 20-25%.

[0010] Preferably, the mud is kneaded three times using a mud kneading machine, and the extrusion pressure at the discharge port of the mud kneading machine is controlled during the mud kneading process. The extrusion pressure at the discharge port of the mud kneading machine is pressurized for the first two of the three mud kneading processes, and is gradually reduced for the two times. The extrusion pressure at the discharge port of the mud kneading machine returns to normal for the third time.

[0011] Preferably, the extrusion pressure of the discharge barrel of the mud trainer is controlled by an outlet pressure regulating device arranged between the extrusion barrel and the discharge barrel of the mud trainer; the outlet pressure regulating device includes a connecting barrel and a pressurizing barrel arranged on the upper part of the connecting barrel, the two ends of the connecting barrel are respectively connected to the extrusion barrel and the discharge barrel, and the pressurizing barrel is connected to the connecting barrel; a mud pressing plate capable of moving in the vertical direction of the pressurizing barrel is arranged in the pressurizing barrel, and the mud pressing plate is driven by a driving mechanism.

[0012] Preferably, the connecting cylinder includes 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 connected to the pressurizing cylinder; a plurality of strip holes extending along the length direction of the inner cylinder are evenly arranged in an annular shape on the side wall of the inner cylinder, and the annular cavity is connected to the inner cylinder through the strip holes.

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

[0014] Preferably, the driving mechanism includes a screw arranged in the upper section of the pressurizing cylinder, the upper end of the screw is connected to the driving motor arranged at the top of the pressurizing cylinder; the screw outer sleeve is provided with a driving sleeve, the driving sleeve is matched with the screw thread, and the driving sleeve is fixedly connected to the mud pressing plate through a crank arm.

[0015] Preferably, the driving sleeve includes a main sleeve sleeved outside the screw and forming a threaded fit with the screw, and a secondary sleeve sleeved outside the lower end of the main sleeve and forming a rotational fit with the main sleeve, and the secondary sleeve is connected to the crank arm;

[0016] The inner wall of the secondary sleeve is provided with a plurality of cylindrical holes evenly arranged in an annular shape and extending radially along the secondary sleeve, and pins with hemispherical ends are arranged in the cylindrical holes; the outer wall of the main sleeve is provided with a hemispherical groove at a position opposite to the pins;

[0017] The top of the secondary sleeve is provided with an annular groove extending downward from the upper end surface, and the annular groove is closed by a cover plate provided on the top of the secondary sleeve, and a vertical adjusting bolt is provided on the cover plate at a position opposite to the annular groove, and the adjusting bolt is threadedly engaged with the cover plate; a pressure ring and a group of butterfly spring pieces are sequentially provided in the annular groove from top to bottom, and a pressure ring is further provided at a position corresponding to the pin below the butterfly spring piece, and the adjusting bolt presses the outer end of the pin by squeezing the pressure ring, the butterfly spring piece and the pressure ring, and causes the pin to extend into the slot on the main sleeve.

[0018] Preferably, an air inlet nozzle connected to the interior of the pressure cylinder is provided on one side of the upper portion of the pressure cylinder, and the air inlet nozzle is connected to the exhaust port of the vacuum device of the mud kneading machine through a pipeline.

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

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

[0021] The beneficial effects of the present invention are embodied in the following: by rationally proportioning kaolin, cordierite, talc, kaolin clinker, and silica powder to form the main ingredients of the clay, the addition of cordierite to the clay of Jianshui purple pottery 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. During rapid temperature fluctuations, the internal stress generated by thermal expansion and contraction in the ceramic product is minimized, allowing for rapid heat transfer during heating, reducing the accumulation of thermal stress in the material within a short period of time. Consequently, thermal shock damage such as cracking and spalling is less likely to occur. Furthermore, the cordierite, through its crystal structure and distribution, inhibits crack propagation, dissipating the energy required for crack expansion, thereby improving the thermal shock resistance of the finished product. Furthermore, the clay exhibits excellent plasticity, with no significant impact on molding. While exhibiting excellent thermal shock resistance, it also combines the advantages of Jianshui purple pottery clay, such as its fine texture and excellent air permeability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a process flow diagram of the present invention;

[0023] Figure 2 It is a structural diagram of the discharge port of an existing mud extruder;

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

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

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

[0027] The present invention relates to a clay material for improving the thermal shock resistance of Jianshui purple pottery and a preparation method thereof. The clay material is mainly used for making finished Jianshui purple pottery products such as tea sets and kitchen utensils. The clay material has the advantages of fine texture and good air permeability of Jianshui purple pottery, and at the same time has good thermal shock resistance, is not easy to crack when heated, and can be cooked over an open fire.

[0028] The present invention incorporates cordierite into the clay used for Jianshui purple pottery, effectively reducing the overall thermal expansion coefficient and improving its thermal conductivity. This mitigates and balances temperature differences between the inside and outside of the material. During rapid temperature fluctuations, the internal stress generated by thermal expansion and contraction in the ceramic product is minimized, allowing for rapid heat transfer during heating, reducing the accumulation of thermal stress in the material over a short period of time. This reduces the risk of thermal shock damage such as cracking and spalling. Furthermore, cordierite, through its crystal structure and distribution, inhibits crack propagation, dissipating the energy required for crack expansion and thus improving the thermal shock resistance of the finished product.

[0029] Purple clay clinker is a powder made by sintering purple clay at a specific temperature and then grinding it. The general sintering temperature is 1100-1250℃. Purple clay clinker is used in the production of Jianshui purple pottery clay with high thermal shock resistance. After adding these clinker powders in a reasonable proportion, the plasticity of the blank can be reduced to a certain extent, the shrinkage of the blank can be reduced, which is conducive to overcoming deformation and cracking of the product, and can also improve thermal stability and mechanical strength.

[0030] The present invention will be described in detail below with reference to the embodiments;

[0031] Example 1

[0032] A clay material for improving the thermal shock resistance of Jianshui purple pottery is prepared by mixing a main ingredient and water. The main ingredient is composed of the following raw materials in weight percentage: 50% of 250-mesh purple clay, 20% of 200-mesh cordierite, 15% of talc, 10% of 300-mesh purple clay clinker, and 5% of 400-mesh silicon powder. The purple pottery is composed of the following raw materials in weight percentage: 50% of five-flowered soil, 15% of loess, 15% of white soil, 10% of gray soil, and 10% of purple soil. After passing each soil material through a 250-mesh sieve, the mixture is evenly mixed according to a certain proportion to form the purple pottery.

[0033] like Figure 1As shown in , the overall preparation process of the clay material described in the present invention is as follows: the main ingredients and water are mixed in a ratio of 1:0.8, stirred thoroughly to ensure a uniform mixture, and then filtered through a 200-mesh sieve to remove impurities; the clay cake is filtered through a filter press to form a clay cake, which is then sent to a clay kneader for kneading three times to prepare a blank with a moisture content of 20-25%. The clay kneader is a ZL-350 vacuum clay kneader produced by Hebi Helong Special Equipment Co., Ltd. When extruding the clay material, the extrusion pressure at the discharge port was measured to be 1.3 MPa.

[0034] Example 2

[0035] The same as Example 1, except that: during the mud kneading, the mud was kneaded three times using a mud kneader. During the mud kneading process, the extrusion pressure at the mud kneader outlet was controlled. The extrusion pressure at the mud kneader outlet was pressurized for the first two times and gradually decreased for the two times. The third time, no pressurization was performed, and the outlet pressure returned to normal. The first and second times were pressurized, with the first pressure being 1.8 MPa, the second pressure being 1.5 MPa, and the third pressure being 1.3 MPa.

[0036] Comparative Example 1

[0037] The preparation method is the same as that of Example 1, except that the cordierite is 15% and the kaolin clinker is 15%.

[0038] Comparative Example 2

[0039] The preparation method is the same as that of Example 1, except that the cordierite is 25% and the kaolin clinker is 5%.

[0040] Comparative Example 3

[0041] The preparation method is the same as that of Example 1, except that the main ingredient formula is: 65% purple clay, 15% talc, 15% purple clay clinker, and 5% silicon powder.

[0042] Comparative Example 4

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

[0044] Plasticity test: The clay materials prepared in Examples 1-2 and Comparative Examples 1-4 were subjected to plasticity analysis. During the analysis, a round rod-shaped sample with a diameter of 2 cm and a length of 20 cm was cut from the clay material through a sampling tube; the sample was held at both ends and bent back and forth in a circular manner. The plasticity was scored based on the presence of fractures and surface cracks. A sample with no fractures or cracks after more than 10 back and forth bends was rated as excellent; a sample with no fractures or cracks after 5-10 back and forth bends was rated as qualified; and a sample with fractures or cracks after less than 5 bends was rated as unqualified (poor plasticity). The results are detailed in Table 1 below.

[0045] Porosity Testing: Ten clay pots each with a diameter of 20 cm and a wall thickness of 1.5 cm were sintered using traditional wheel throwing techniques using the clay materials from Examples 1-2 and Comparative Examples 1-4. The porosity of each of these ten samples was tested by weighing them in air, then completely immersing them in water until the pores were filled with water. The surface water stains were wiped clean with a dry towel, and the samples were weighed again. Based on these two weighings and the density of water, the volume of water in the sample (i.e., the pore volume) was calculated. Finally, the porosity was calculated. The average porosity of the ten samples in each Example or Comparative Example was used as the final value (rounded to one decimal place). The results are detailed in Table 1 below.

[0046] Thermal shock resistance test: 10 casserole samples in each of Examples 1-2 and Comparative Examples 1-4 after the porosity test were subjected to a thermal shock resistance test. During the test, each casserole sample was kept at 1300°C for 5 minutes, placed in water with a temperature below 5°C and cooled for 1 minute. The above process was repeated until the casserole cracked or broke and was recorded as damaged. The number of cycles before damage was recorded. The average number of thermal shock resistance cycles of the 10 samples in each Example or Comparative Example was used as the final data (rounded to an integer). The results are shown in Table 1 below.

[0047] Yield rate test: 100 ceramic cups with a diameter of 5 cm were made in batches from the clay materials of Examples 1-2, and the traditional method of wheel throwing, shaping, and sintering was adopted for production. The defects of the 100 ceramic cups of Example 1 and Example 2 were judged, and those with uneven surface, small particles in some areas, small bubbles, etc. were considered defective products. The yield rate was also statistically analyzed, and the results are shown in Table 1 below.

[0048] Table 1 Statistics of plasticity and thermal shock resistance of the clay materials in the examples and comparative examples

[0049] plasticity Thermal shock resistance Porosity Yield Example 1 Excellent 18 10.5% 95% Example 2 Excellent 23 11.2% 99% Comparative Example 1 qualified 12 10.5% Comparative Example 2 Excellent 10 9.8% Comparative Example 3 Unqualified 8 11.7% Comparative Example 4 Excellent 11 9.7%

[0050] As can be seen from Table 1, the clay material of the present invention has good plasticity and no significant effect on molding. It has the advantages of Jianshui purple pottery clay material of fine texture and good air permeability, and has a significant improvement in thermal shock resistance.

[0051] After three cycles of clay kneading using a clay kneading machine and controlling the pressure, its thermal shock resistance was further improved, and the product yield rate was excellent. The inventors believe the reason is as follows: Due to the fine and dense texture of Jianshui purple pottery, the air inside the clay is difficult to expel during the clay refining process, necessitating multiple cycles of clay kneading using a vacuum clay kneading machine. Otherwise, holes are likely to appear in the clay, affecting the quality of the finished product. By increasing the extrusion pressure at the clay kneading machine outlet and combining multiple cycles of clay kneading, the clay can be made more dense, assisting in the expulsion of air from the clay, and reducing internal holes.

[0052] The present invention adopts three times of mud kneading, and the first two times the discharge port is pressurized. On the one hand, it can assist in the discharge of gas in the mud, improve the density, and eliminate the hole defects that may appear in the later stage. On the other hand, during the last mud kneading, the normal discharge port pressure of the mud kneading machine is used. Since the mud enters the mud kneading machine again after being pressurized and exhausted and squeezed out, it is broken and transported by the cutter teeth. Although there is a risk of secondary hole generation at this time, the mud is under the protection of the vacuum system during the mud kneading process, so the impact is not significant. On the contrary, this method of restoring normal pressure treatment can restore the overpressure defect caused by pressurization, restore the plasticity and uniformity of the mud, and reduce the risk of uneven particles. The present invention has an excellent guarantee of the final yield of the finished product through reasonable and effective processing procedures.

[0053] Of course, when controlling the pressure of the discharge port, in theory, by reducing the size of the discharge port, although the extrusion pressure can be significantly increased and the hole defects in the clay blank can be reduced, this method is not universal due to the requirements of the clay blank size for wheel throwing, and the frequent replacement of the discharge port also increases the complexity of the operation. Increasing the pressure by increasing the operating speed of the main shaft will increase the output power of the main motor, which has the risk of burning the machine. Simply replacing high-power new equipment to meet the demand for increasing the extrusion pressure will obviously also cause a huge economic burden on the company, which is not desirable. How to achieve the effect of supercharging by modifying the existing model on the basis of the existing mud extruder is also a very important issue. For this reason, the present invention also discloses a mud extruder outlet pressure regulating device that is suitable for the modification of the existing model and can effectively control the pressure of the discharge port. The extrusion pressure of the mud extruder outlet is controlled by the outlet pressure regulating device arranged between the mud extruder extrusion barrel and the discharge port.

[0054] The discharge port of the existing mud making machine is as follows Figure 2 As shown in FIG, the extrusion cylinder 3 and the discharge cylinder 4 are directly flange-connected. The pressure regulating device of the present invention is as follows Figure 3-5 As shown in , the outlet pressure regulating device 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 adapt to the installation requirements of various models. The two ends of the connecting cylinder 1 are respectively connected to the extrusion cylinder 3 and the discharge cylinder 4, and the pressurizing cylinder 2 is connected to the connecting cylinder 1. The connection between the connecting cylinder 1 and the extrusion cylinder 3 and the discharge cylinder 4 is also directly flange-connected, that is, flanges are provided at both ends of the connecting cylinder 1, and are connected to the extrusion cylinder 3 and the discharge cylinder 4 through the flanges. In order to ensure the tightness of the connection, a sealing gasket can be added between the two flanges. In addition, in order to facilitate the mud in the extrusion cylinder 3 to enter the connecting cylinder 1, the connecting cylinder 1 is formed with a stepped surface corresponding to the inner cavity of the extrusion cylinder 3 near one end of the extrusion cylinder 3, and a sealing ring 27 with a triangular cross-section is provided on the stepped surface.

[0055] The pressurizing cylinder 2 is provided with a mud pressing plate 5 capable of moving in the vertical direction of the pressurizing cylinder 2. The mud pressing plate 5 is driven by a driving mechanism. The specific structure of the driving mechanism is relatively large. From the perspective of implementation alone, it can be, for example: a hydraulic cylinder (simple to control, but relatively expensive), a pneumatic cylinder (simple to control, but relatively poor extrusion force, requiring special customization, and the pressurization is not stable enough).

[0056] When first used, the discharge port of the discharge barrel 4 is sealed with a plug. After the main shaft of the clay making machine squeezes the clay material and fills the discharge barrel 4, the connecting barrel 1, and the lower section of the pressurizing barrel 2, the plug is opened and the material is discharged normally. The pressure at the discharge port is detected by the pressure sensor set in the discharge barrel 4. When pressurizing, the drive mechanism controls the clay pressing plate 5 to press down, and the main shaft of the clay making machine squeezes the clay material together, thereby testing the purpose of pressurization. This type of pressure regulating device is convenient for modifying the discharge port pressure control of existing equipment without significantly increasing the economic burden of the enterprise.

[0057] In order to distribute the pressure from the mud pressing plate 5 more evenly to the mud material at the connecting tube 1 and the discharging tube 4, the connecting tube 1 may include an inner tube 6 and an outer tube 7, which are generally assembled in a detachable connection to facilitate disassembly and cleaning after use, and to facilitate secondary use. An annular cavity 8 is formed between the inner tube 6 and the outer tube 7, and the annular cavity 8 is connected to the pressurizing tube 2; a plurality of strip holes 9 extending along the length direction of the inner tube 6 are evenly arranged on the side wall of the inner tube 6 in an annular shape, and the annular cavity 8 is connected to the inner tube 6 through the strip holes 9. In this way, the mud material can be squeezed inward from the circumference through the annularly distributed strip holes 9, and the overall extrusion uniformity is better. Generally, 4-6 strip holes 9 are sufficient, and too many are not conducive to the overall structural strength of the inner tube 6.

[0058] In an alternative solution, for some low-viscosity materials with high fluidity, in order to increase the extrusion force, prevent the mud from flowing back into the annular cavity 8 and the pressure cylinder 2, and reduce the load of the mud pressing plate 5, a combination of Figure 3 and 5 As shown in , a pressure nozzle 10 is provided on the inner side wall of the inner cylinder 6 corresponding to the strip hole 9. The pressure nozzle 10 extends along the length direction of the strip hole 9, and the inner cavity of the pressure nozzle 10 gradually narrows from the outside to the inside.

[0059] Regarding the specific form of the driving mechanism, a feasible solution is as follows Figure 3As shown in , the driving mechanism of the present invention includes a screw 11 arranged in the upper section of the pressurizing cylinder 2, and the upper end of the screw 11 is connected to the driving motor 12 arranged at the top of the pressurizing cylinder 2; the outer sleeve of the screw 11 is provided with a driving sleeve 13, and the driving sleeve 13 is threadedly matched with the screw 11, and the driving sleeve 13 is fixedly connected to the mud pressing plate 5 through the crank arm 14. The driving motor 12 continuously outputs power to the screw 11, and the screw 11 is used to drive the mud pressing plate 5 downward through the driving sleeve 13 and the crank arm 14. At this time, the pressurizing cylinder 2 is generally a square cylinder, and the pressure plate 5 is a square plate that slides with it. However, in this case, in order to achieve pressure control and pressure limiting protection for the driving motor 12, the driving sleeve 13 of the present invention can achieve power tripping when the set pressure is exceeded, and can connect power when the pressure is insufficient, driving the mud pressing plate 5 to continue to press down.

[0060] For this reason, Figure 4 As shown in the figure, the drive sleeve 13 includes a main sleeve 15 which is sleeved outside the screw rod 11 and forms a threaded fit with the screw rod 11, and a secondary sleeve 16 which is sleeved outside the lower end of the main sleeve 15 and forms a rotational fit with the main sleeve 15, and the secondary sleeve 16 is connected to the crank arm 14.

[0061] The structure for realizing power connection and power release is as follows: a plurality of cylindrical holes 17 extending radially along the secondary sleeve 16 are evenly arranged on the inner side wall of the secondary sleeve 16 in an annular shape, and a pin 18 with hemispherical ends is arranged in the cylindrical hole 17; a hemispherical card groove 19 is provided on the outer side wall of the main sleeve 15 at a position opposite to the pin 18; an annular groove 20 extending downward from the upper end surface is provided on the top of the secondary sleeve 16, and the annular groove 20 is closed by a cover plate 21 provided on the top of the secondary sleeve 16, and the cover plate A vertical adjusting bolt 22 is provided at a position on 21 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 group of butterfly spring pieces 24 are sequentially provided in the annular groove 20 from top to bottom, and a pressure ring 25 is further provided at a position corresponding to the pin 18 below the butterfly spring piece 24. The adjusting bolt 22 presses the outer end of the pin 18 by squeezing the pressure ring 23, the butterfly spring piece 24 and the pressure ring 25, and makes the pin 18 extend into the slot 19 on the main sleeve 15.

[0062] When the pressure is insufficient, the screw 11 can continue to drive the drive sleeve 13, thereby driving the mud press plate 5 downward through the crank arm 14. When the power reaches the set value (set by the adjusting bolt 22), the driving sleeve 13 cannot continue to move downward 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, retracting the pin 18 from the slot 19 into the column hole 17, achieving the separation of the main sleeve 15 and the auxiliary sleeve 16, thus achieving power release. When the pressure needs to be adjusted, the side door on the upper side of the pressurizing cylinder 2 can be opened and the adjusting bolt 22 can be turned.

[0063] On this basis, to further enhance the performance of the pressure regulating device, an air inlet nozzle 26 is provided on one side of the upper portion of the pressure cylinder 2, communicating with the interior of the pressure cylinder 2. The air inlet nozzle 26 is connected to the exhaust port of the vacuum device of the clay extruder via a pipeline. The air inlet nozzle 26 can be connected to the exhaust port of the vacuum device, and the pressurized air pumped out by the vacuum device is used to pressurize the interior of the pressure cylinder 2, thereby increasing the internal pressure of the pressure cylinder 2 and reducing the load on the drive motor 12 and the load on the clay 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: The main material is mixed and stirred with water, wherein the main material is composed of the following raw materials in the following weight percentages: 50% kaolin, 20% cordierite, 15% talc, 10% kaolin clinker, and 5% silicon powder.

2. The clay material for improving the thermal shock resistance of Jianshui purple pottery according to claim 1, characterized in that: The purple clay is composed of the following raw materials in the following weight percentages: 50% of five-flowered clay, 15% of loess, 15% of white clay, 10% of gray clay, and 10% of purple clay.

3. The clay material for improving the thermal shock resistance of Jianshui purple pottery according to claim 2, characterized in that: The weight ratio of the main material to water is 1:0.

8.

4. The clay material for improving the thermal shock resistance of Jianshui purple pottery according to claim 3, characterized in that: The particle sizes of the raw materials in the main ingredients are 250 meshes of kaolin, 200 meshes of cordierite, 300 meshes of talc, 200 meshes of kaolin clinker, and 400 meshes of silicon micropowder.

5. The method for preparing a clay material for improving the thermal shock resistance of Jianshui purple pottery according to any one of claims 1 to 4, characterized in that: The main material and water are mixed in a ratio of 1:0.8, stirred thoroughly to make the mixture uniform, and passed through a 200-mesh sieve to remove impurities; the mixture is filtered through a filter press to form a mud cake, which is sent to a mud kneading machine for mud kneading to prepare a blank with a moisture content of 20-25%.

6. The method for preparing clay material for improving the thermal shock resistance of Jianshui purple pottery according to claim 5, characterized in that: The mud is kneaded three times on a mud kneading machine, and the extrusion pressure at the discharge port of the mud kneading machine is controlled during the kneading process. The extrusion pressure at the discharge port of the mud kneading machine is pressurized for the first two of the three times, and is gradually reduced for the two times. The extrusion pressure at the discharge port of the mud kneading machine returns to normal for the third time.

7. The method for preparing clay material for improving the thermal shock resistance of Jianshui purple pottery according to claim 6, characterized in that: The extrusion pressure of the mud extruder outlet is controlled by an outlet pressure regulating device arranged between the mud extrusion cylinder and the outlet.

Images