Preparation method of high-purity alumina ceramic green tape

Abstract

The invention belongs to the technical field of preparation of aluminum oxide ceramic green tapes, and particularly relates to a preparation method of a high-purity aluminum oxide ceramic green tape. An adjusting assembly is installed in a drying box, a temperature supply assembly is installed on the drying box, and the temperature supply assembly and a steam tank are installed on a support; the adjusting assembly comprises a fixed plate and a driving plate, the fixed plate is fixedly installed in the drying box, the movable driving plate is installed in the drying box, the interior of the drying box is divided into a low-temperature cavity, a moisturizing cavity and a high-temperature cavity through the fixed plate and the driving plate, a fixed hole plate is installed on the fixed plate, a movable hole plate is installed on the driving plate, and a moisture sensor is installed in the drying box. The fluidity of the slurry on the green tape is detected through the moisture sensor at the inlet of the drying box, namely, the moisture content of the slurry is detected, the cavity space of the low-temperature cavity and the steam input amount of the moisturizing cavity are controlled according to the fluidity of the slurry, and the solvent removal time is adjusted according to the slurry with different fluidity.

Description

Technical Field

[0001] The invention belongs to the technical field of alumina ceramic green tape preparation, and specifically relates to a method for preparing a high-purity alumina ceramic green tape. Background Art

[0002] Alumina ceramic green tape is a flexible material made of high-purity alumina powder. It is widely used in electronic packaging, circuit substrates and other fields. The quality of electronic ceramic products depends to a large extent on the quality of the green tape. Therefore, the preparation of high-quality green tape has become the key to the development of functional ceramics.

[0003] Tape casting is an important process for batch production of high-quality green ceramic tapes. In the tape casting process, ceramic powder, adhesive, plasticizer and solvent are first mixed and evenly ball-milled to form a ceramic slurry with a certain viscosity coefficient; the PET film tape is used as the tape casting substrate, and the treated ceramic slurry is tape-cast to form a green ceramic tape; the green ceramic tape after tape casting is dried to remove the residual solvent and improve the strength of the green ceramic tape. The drying process of the ceramic body is an important part of the tape casting production process, which directly affects the production efficiency and quality of the product.

[0004] During the drying process of the ceramic body, the solvent in the ceramic body tends to volatilize as the temperature rises, causing cracks or deformation in the green ceramic tape. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a high-purity alumina ceramic green tape in view of the shortcomings of the prior art, so as to solve the technical problems in the prior art.

[0006] The purpose of the present invention can be achieved by the following technical solution: A method for preparing a high-purity alumina ceramic green tape, which comprises the following specific steps: Step S1: adding ceramic powder into a ball mill, adding a dispersant, deionized water, a binder, a plasticizer and a solvent according to the proportion of the powder, mixing evenly and obtaining a mixture A; Step S2: adding a defoaming agent and a film-forming aid to the mixture A step by step, and continuing to ball mill with a planetary ball mill to obtain a mixture B; then placing the mixture B in a vacuum stirring tank for degassing to obtain a ceramic slurry; Step S3: heating, stirring and keeping the ceramic slurry warm, using the PET film tape as a tape-casting substrate, and tape-casting the treated ceramic slurry to obtain a green ceramic tape; Step S4: Place the green porcelain tape after casting in a drying box. The conveying device drives the green porcelain tape through the low-temperature chamber, the moistening chamber and the high-temperature chamber in sequence. During this process, the moisture sensor at the entrance of the drying box detects the fluidity of the slurry on the green porcelain tape, and the multi-stage heating plate inside the drying box assists in heating the green porcelain tape.

[0007] As a further optimization or improvement of this solution, step S4 specifically includes the following steps: Step S401: When the fluidity of the slurry on the green porcelain belt is low, the moisture sensor controls the cylinder to extend, and the cylinder drives the active plate to move from the moistening chamber to the low-temperature chamber through the push-pull rod. The slider on the active plate drives the connecting rod and the driven plate to move. When the cylinder drives the active plate to pass over one of the low-temperature branch pipes, it stops. At this time, the cavity space of the low-temperature chamber is reduced, and the cavity space of the moistening chamber is increased; Step S402: When the cylinder 7 drives the active plate 802 and the driven plate 803 to move, the movable orifice plate 806 on the active plate 802 moves relative to the fixed orifice plate 807, and the through holes on the movable orifice plate 806 gradually overlap with the through holes on the fixed orifice plate 807; Step S403: When the green porcelain tape passes through the low-temperature chamber, the time it takes for the green porcelain tape to pass through the low-temperature chamber is reduced due to the reduced space of the low-temperature chamber. At the same time, the low-temperature branch pipe blows dry hot air into the low-temperature chamber to provide a low-humidity volatile environment while removing the solvent inside the green porcelain tape. Step S404: When the green porcelain belt passes through the moistening chamber, the steam tank injects steam into the moistening chamber. Since the high-temperature branch pipe and the low-temperature branch pipe are both located inside the moistening chamber, the hot air from the high-temperature branch pipe and the low-temperature branch pipe is introduced into the moistening chamber to mix and heat the steam, so that the temperature of the steam and hot air inside the moistening chamber is balanced between the temperature of the low-temperature chamber and the temperature of the high-temperature chamber. At this time, the steam and hot air inside the moistening chamber are blown toward the green porcelain belt through the through holes on the fixed orifice plate and the movable orifice plate; Step S405: When the green porcelain tape passes through the high-temperature chamber, the high-temperature air pressure tank heats the green porcelain tape inside the high-temperature chamber through the high-temperature branch pipe to dry it.

[0008] As a further optimization or improvement of this solution, step S4 specifically includes the following steps: Step S411: When the fluidity of the slurry on the green porcelain belt is strong, the moisture sensor controls the cylinder to retract. As the cylinder drives the active plate to move toward the moisturizing chamber, the push-pull rod drives the slider to slide along the slide slot to separate the active plate from the driven plate. When the active plate returns to its previous position, the cylinder is closed. During this process, the low-temperature chamber space increases and the moisturizing chamber space decreases. Step S412: When the cylinder drives the active plate to move, the movable orifice plate on the active plate moves relative to the fixed orifice plate, so that the through holes on the movable orifice plate and the through holes on the fixed orifice plate are gradually staggered, and the steam output of the moisturizing chamber is reduced; Step S413: When the green porcelain belt passes through the low-temperature chamber, the cavity space of the low-temperature chamber increases, the time for the green porcelain belt to pass through the low-temperature chamber increases, and at the same time, the moisture absorbing block can absorb the moisture inside the low-temperature chamber; Step S414: When the raw porcelain tape passes through the moistening chamber, the slurry has strong fluidity and can automatically flow to smooth out the fine cracks caused by volatilization inside the raw porcelain tape. The moistening chamber does not need to use steam to increase the fluidity of the slurry. The multi-stage heating plate is started, and the multi-stage heating plate with step-by-step heating gradually heats the raw porcelain tape.

[0009] As a further optimization or improvement of this solution, a regulating component is installed in the drying box, a heating component is installed on the drying box, and a heating component and a steam tank are installed on the bracket; The adjustment component includes a fixed plate and an active plate, the fixed plate is fixedly installed in the drying box, a movable active plate is installed inside the drying box, the fixed plate and the active plate divide the inside of the drying box into a low-temperature chamber, a moistening chamber and a high-temperature chamber, a fixed orifice plate is installed on the fixed plate, and a movable orifice plate is installed on the active plate, and the movable orifice plate and the fixed orifice plate are slidably matched; The heating component comprises a high-temperature pressure tank and a low-temperature pressure tank, the high-temperature pressure tank is connected to the high-temperature cavity, the low-temperature pressure tank is connected to the low-temperature cavity, the steam tank is connected to the moisturizing cavity, and a moisture sensor is installed in the drying box.

[0010] As a further optimization or improvement of this solution, a cylinder is installed inside the moisturizing chamber, and the cylinder is connected to the active plate through a push-pull rod. A plurality of multi-stage heating plates are installed at the bottom of the drying box, and exhaust fans are installed on both the low-temperature chamber and the high-temperature chamber.

[0011] As a further optimization or improvement of this solution, a connecting rod is installed on the driven plate, a sliding groove is opened inside the connecting rod, a sliding block is installed on the push-pull rod, the sliding block slides inside the sliding groove, an electromagnetic suction cup is installed inside the sliding groove, and the electromagnetic suction cup adsorbs the sliding block.

[0012] As a further optimization or improvement of the present solution, a sealing frame is installed on the driven plate, a moisture absorbing block is installed on the active plate, and the sealing frame covers the moisture absorbing block.

[0013] As a further optimization or improvement of the present solution, sealing strips are installed on the fixed plate and the active plate, and the fixed plate and the active plate contact the top of the drying box through the sealing strips thereon.

[0014] As a further optimization or improvement of this solution, the low-temperature pressure tank is connected to the low-temperature cavity through a low-temperature branch pipe, and the high-temperature pressure tank is connected to the high-temperature cavity through a high-temperature branch pipe, and one of the heads on the high-temperature branch pipe is located in the humidification cavity.

[0015] As a further optimization or improvement of this solution, the solvent is a mixture of anhydrous ethanol, butanone and n-butanol.

[0016] Beneficial effects of the present invention: (1) The present invention detects the fluidity of the slurry on the green porcelain belt through a moisture sensor; when the fluidity of the slurry on the green porcelain belt is low, the low-temperature chamber space is reduced by the cylinder, the steam output of the moistening chamber is increased, and the time for the green porcelain belt to pass through the low-temperature chamber is reduced, so as to avoid the slurry with low fluidity on the green porcelain belt being in the low-temperature chamber for a long time, which leads to excessive drying and cracking of the slurry. At the same time, since the low-temperature branch pipe blows dry hot air into the low-temperature chamber, a low-humidity volatilization environment is provided while removing the solvent inside the green porcelain belt; Furthermore, when the raw porcelain belt passes through the moistening chamber, the steam tank injects steam into the moistening chamber. Since the high-temperature branch pipe and the low-temperature branch pipe are both located inside the moistening chamber, the hot air from the high-temperature branch pipe and the low-temperature branch pipe enters the moistening chamber to mix and heat the steam, so that the temperature of the steam and hot air inside the moistening chamber is balanced between the temperatures of the low-temperature chamber and the high-temperature chamber. At this time, the steam and hot air inside the moistening chamber are blown toward the raw porcelain belt through the through holes on the fixed orifice plate and the movable orifice plate, so that it gradually heats the raw porcelain belt and reduces the influence of the temperature difference between the low-temperature chamber and the high-temperature chamber on the raw porcelain belt. At the same time, the high-humidity steam can improve the fluidity of the slurry on the green porcelain belt, accelerate the flow of slurry, and smooth out the fine cracks caused by the volatilization of the solvent from the inside of the green porcelain belt.

[0017] (2) When the fluidity of the slurry on the green porcelain belt is strong, that is, the amount of solvent inside the slurry is large, the cylinder controls the increase of the low-temperature chamber space, controls the steam output of the moisturizing chamber to decrease, and controls the moisture absorption block to be exposed in the low-temperature chamber, so that the time for the green porcelain belt to pass through the low-temperature chamber is increased, thereby completely removing the solvent inside the green porcelain belt. The moisture absorption block can absorb the moisture inside the low-temperature chamber, providing a drier environment for the low-temperature chamber, and cooperates with the dry hot air of the low-temperature branch pipe to remove the moisture in the slurry while increasing the volatility of ethanol in the solvent; Furthermore, when the raw porcelain belt passes through the wetting chamber, the steam output of the wetting chamber is reduced or stopped due to the staggered through holes on the movable orifice plate and the fixed orifice plate. At the same time, due to the strong fluidity of the slurry, the slurry can automatically flow to smooth out the fine cracks caused by volatilization inside the raw porcelain belt, and the wetting chamber does not need to use steam to increase the fluidity of the slurry. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings.

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0020] Figure 2 It is a schematic diagram of the internal structure of the present invention.

[0021] Figure 3 It is a front view of the internal structure of the present invention.

[0022] Figure 4 for Figure 3 A magnified view of the structure of part A.

[0023] Figure 5 This is an exploded view of the overall structure of the adjustment component.

[0024] Figure 6 This is a schematic diagram of the connection between the cylinder and the adjustment component.

[0025] Figure 7 for Figure 6 Schematic diagram of the structure of part B.

[0026] The following are marked in the figure: 1. Drying box; 101. Low-temperature chamber; 102. Moisturizing chamber; 103. High-temperature chamber; 2. Bracket; 3. Heating component; 301. High-temperature pressure tank; 302. High-temperature branch pipe; 304. Low-temperature pressure tank; 305. Low-temperature branch pipe; 4. Steam tank; 5. Exhaust fan; 6. Multi-stage heating plate; 7. Cylinder; 8. Adjustment component; 801. Fixed plate; 802. Active plate; 803. Driven plate; 804. Sealing frame; 805. Moisture absorbing block; 806. Moisture absorbing block; 807. Fixed orifice plate; 808. Connecting rod; 809. Slide; 810. Push-pull rod; 811. Sliding block; 812. Electromagnetic suction cup; 813. Sealing strip; 9. Moisture sensor. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] See also Figure 1-Figure 7 A method for preparing a high-purity alumina ceramic green tape comprises the following specific steps: Step S1: adding ceramic powder into a ball mill, adding a dispersant, deionized water, a binder, a plasticizer and a solvent according to the proportion of the powder, mixing evenly and obtaining a mixture A; Step S2: adding a defoaming agent and a film-forming aid to the mixture A step by step, and continuing to ball mill with a planetary ball mill to obtain a mixture B; then placing the mixture B in a vacuum stirring tank for degassing to obtain a ceramic slurry; Step S3: heating, stirring and keeping the ceramic slurry warm, using the PET film tape as a tape-casting substrate, and tape-casting the treated ceramic slurry to obtain a green ceramic tape; Step S4: Place the green porcelain tape after casting in the drying box 1, and the conveying device drives the green porcelain tape to pass through the low-temperature chamber 101, the moistening chamber 102 and the high-temperature chamber 103 in sequence. During this process, the moisture sensor 9 at the entrance of the drying box 1 detects the fluidity of the slurry on the green porcelain tape, and the multi-stage heating plate 6 inside the drying box 1 assists in heating the green porcelain tape.

[0029] It should be noted that the conveying device is a conventional conveyor belt in the prior art, and the present invention will not describe it in detail, which does not affect the integrity of this solution.

[0030] The ceramic powder of the present invention includes 996 alumina, 96 alumina, 90 black porcelain and 92 black porcelain; Based on different powders, the mixture is uniformly mixed with dispersant, deionized water, binder and plasticizer in proportion, and ball milled for about 5 hours to obtain mixture A; then the defoamer and film-forming aid are added to the mixture A step by step, and the mixture B is obtained by using a planetary ball mill for further ball milling for about 5 hours; then the mixture B is degassed in a vacuum stirring tank for 5-10 hours to obtain a ceramic slurry with a viscosity in the range of 5000-15000m Pa·S; the ceramic slurry is heated, stirred and kept warm at a temperature of 30°C, characterized in that the casting preparation zone prevents its sedimentation, and the stirring speed is 15rpm. Then, the PET film tape is used as the casting substrate, and the treated ceramic slurry is tape-cast to obtain a raw porcelain tape; the raw porcelain tape state during the casting is set to apply a 90N pulling force to the raw tape through a roller at a temperature of 30°C, the gap between the equipment scraper and the conveyor belt is 0.2-2mm (adjusted according to the thickness of the raw porcelain tape produced), and the conveyor belt speed is 0.1-0.6m / min. The air inlet speed of the low temperature chamber 101 is set to 500-550rpm, and the exhaust speed is 1550-1650rpm. The air inlet speed of the high temperature chamber 103 is set to 450-500rpm, and the exhaust speed is 1500-1550rpm.

[0031] When the present invention produces 96 alumina, the thickness of the green porcelain tape obtained by tape casting is 500mm or more, 300-500mm and less than 300mm. When the tape casting thickness is less than 300mm, the viscosity of the slurry is adjusted to 5000-6000Pa·s by vacuum degassing.

[0032] The temperature of the multi-stage heating plate 6 is set to 35, 45, 55, 60, and 70°C. The air inlet of the low-temperature chamber 101 is 450rpm, the exhaust of the low-temperature chamber 101 is 1450rpm, the air inlet of the high-temperature chamber 103 is 500rpm, and the exhaust of the high-temperature chamber 103 is 1550rpm. When the casting thickness is 300-500mm, the viscosity of the slurry is regulated to 10000-11000Pa·s by vacuum degassing. The temperature of the multi-stage heating plate 6 is set to 42, 53, 63, 70, and 80. The air inlet of the low-temperature chamber 101 is 450rpm, the exhaust of the low-temperature chamber 101 is 1450rpm, the air inlet of the high-temperature chamber 103 is 500rpm, and the exhaust of the high-temperature chamber 103 is 1550rpm. When the casting thickness is greater than 500mm, the viscosity coefficient is 12000-15000Pa·s after vacuum degassing, and the other parameters are the same as 300-500mm.

[0033] When the present invention produces 996 alumina, the thickness of the green porcelain tape obtained by tape casting is 500 mm or more, 300-500 mm or less and 300 mm or less. When the tape casting thickness is less than 300 mm, the viscosity of the slurry is adjusted to 5000-7000 Pa·s by vacuum degassing.

[0034] The temperature of the multi-stage heating plate 6 is set to 40, 50, 55, 60, 60°C. The air inlet of the low-temperature chamber 101 is 450rpm, the exhaust of the low-temperature chamber 101 is 1450rpm, the air inlet of the high-temperature chamber 103 is 500rpm, and the exhaust of the high-temperature chamber 103 is 1550rpm. When the casting thickness is 300-500mm, the viscosity of the slurry is adjusted to 9000-11000Pa·s by vacuum degassing. The temperature of the multi-stage heating plate 6 is set to 40, 50, 60, 70, 80°C. The air inlet of the low-temperature chamber 101 is 550rpm, the exhaust of the low-temperature chamber 101 is 1650rpm, the air inlet of the high-temperature chamber 103 is 500rpm, and the exhaust of the high-temperature chamber 103 is 1550rpm. The viscosity coefficient is 12000-14000 during true degassing treatment, and the other parameters are the same as 300-500mm.

[0035] When the present invention produces alumina 90 black porcelain / 92 black porcelain, the thickness of the raw porcelain tape obtained by casting is four specifications, namely, above 330 mm, 330 mm, 133-264 mm, and within 133 mm. When the casting thickness is lower than 133 mm, the slurry viscosity is regulated to be 5000-5500 Pa·s by vacuum degassing. The temperature of the multi-stage heating plate 6 is set to 40, 50, 55, 60, and 60°C. The air inlet of the low-temperature chamber 101 is 450 rpm, the exhaust of the low-temperature chamber 101 is 1450 rpm, the air inlet of the high-temperature chamber 103 is 500 rpm, and the exhaust of the high-temperature chamber 103 is 1550 rpm. When the casting thickness is 133-264 mm, the slurry viscosity is regulated to be 8000-9000 Pa·s by vacuum degassing, and the other parameters are the same as those below 133 mm. When the casting thickness is 330mm, the slurry viscosity is regulated to 10000-11000Pa·s by vacuum degassing. The temperature of the multi-stage heating plate 6 is set to 40, 50, 60, 70, 80℃. The air inlet of the low-temperature chamber 101 is 600rpm, the exhaust of the low-temperature chamber 101 is 1650rpm, the air inlet of the high-temperature chamber 103 is 550rpm, and the exhaust of the high-temperature chamber 103 is 1550rpm. When the casting thickness is greater than 330mm, the viscosity coefficient is 12000-15000Pa·s after vacuum degassing, and the other parameters are the same as 330mm.

[0036] The particle size of the ceramic powder selected in the process of preparing the green porcelain tape is 3-4μm. The ceramic particle size of 3-4μm can make the powder distribution more uniform while ensuring the packing density of the green porcelain tape, so that the powder can form a more compact packing structure, thereby improving the density of the green porcelain tape. After sintering, the pores and porosity of the ceramic core are small, and the grain boundary density is increased, thereby ensuring the microstructure and properties of the ceramic core, such as bending strength and creep resistance.

[0037] The solvent preferably includes one or more of toluene, xylene, butanone, ethanol and ethyl acetate, so that the solvent can fully disperse the components, improve the fluidity of the alumina ceramic casting slurry, and have good volatility.

[0038] See also Figure 3-Figure 7 , the step S4 specifically comprises the following steps: Step S401: When the fluidity of the slurry on the green porcelain belt is low, the moisture sensor 9 controls the cylinder 7 to extend, and the cylinder 7 drives the active plate 802 to move from the moistening chamber 102 to the low-temperature chamber 101 through the push-pull rod 810. The slider 811 on the active plate 802 drives the connecting rod 808 and the driven plate 803 to move. When the cylinder 7 drives the active plate 802 to cross one of the low-temperature branch pipes 305, it stops. At this time, the cavity space of the low-temperature chamber 101 is reduced, and the cavity space of the moistening chamber 102 is increased; Step S402: When the cylinder 7 drives the active plate 802 and the driven plate 803 to move, the movable orifice plate 806 on the active plate 802 moves relative to the fixed orifice plate 807, and the through holes on the movable orifice plate 806 gradually overlap with the through holes on the fixed orifice plate 807; Step S403: When the green porcelain tape passes through the low temperature chamber 101, the time for the green porcelain tape to pass through the low temperature chamber 101 is reduced due to the reduction of the cavity space of the low temperature chamber 101. At the same time, the low temperature branch pipe 305 blows dry hot air into the low temperature chamber 101, providing a low humidity volatilization environment while removing the solvent inside the green porcelain tape; Step S404: When the green porcelain belt passes through the moistening chamber 102, the steam tank 4 injects steam into the moistening chamber 102. Since the high-temperature branch pipe 302 and the low-temperature branch pipe 305 are both located inside the moistening chamber 102, the hot air from the high-temperature branch pipe 302 and the low-temperature branch pipe 305 is introduced into the moistening chamber 102 to mix and heat the steam, so that the temperature of the steam and hot air inside the moistening chamber 102 is balanced between the temperature of the low-temperature chamber 101 and the temperature of the high-temperature chamber 103. At this time, the steam and hot air inside the moistening chamber 102 are blown toward the green porcelain belt through the through holes on the fixed orifice plate 807 and the movable orifice plate 806; Step S405: When the green porcelain tape passes through the high temperature chamber 103, the high temperature pressure tank 301 heats the green porcelain tape inside the high temperature chamber 103 through the high temperature branch pipe 302 to dry it.

[0039] See also Figure 3-Figure 7 , the step S4 specifically comprises the following steps: Step S411: When the fluidity of the slurry on the green porcelain belt is strong, the moisture sensor 9 controls the cylinder 7 to retract. As the cylinder 7 drives the active plate 802 to move toward the moistening chamber 102, the push-pull rod 810 drives the slider 811 to slide along the slide groove 809, so that the active plate 802 is separated from the driven plate 803. When the active plate 802 returns to its previous position, the cylinder 7 is closed. In this process, the space of the low-temperature chamber 101 increases, and the space of the moistening chamber 102 decreases. Step S412: When the cylinder 7 drives the active plate 802 to move, the movable orifice plate 806 on the active plate 802 moves relative to the fixed orifice plate 807, so that the through holes on the movable orifice plate 806 and the through holes on the fixed orifice plate 807 are gradually staggered, and the steam output of the moisturizing chamber 102 is reduced; Step S413: When the green porcelain tape passes through the low temperature chamber 101, the cavity space of the low temperature chamber 101 increases, the time for the green porcelain tape to pass through the low temperature chamber 101 increases, and at the same time, the moisture absorption block 805 can absorb the moisture inside the low temperature chamber 101; Step S414: When the raw porcelain tape passes through the moistening chamber 102, the slurry has strong fluidity and can automatically flow to smooth out the fine cracks caused by volatilization inside the raw porcelain tape. The moistening chamber 102 does not need to use steam to increase the fluidity of the slurry. The multi-stage heating plate 6 is started, and the multi-stage heating plate 6 with step-by-step heating gradually heats the raw porcelain tape.

[0040] See also Figure 3-Figure 7 , the adjustment component 8 is installed in the drying box 1, the heating component 3 is installed on the drying box 1, and the heating component 3 and the steam tank 4 are installed on the bracket 2; The regulating assembly 8 comprises a fixed plate 801 and an active plate 802. The fixed plate 801 is fixedly installed in the drying box 1. A movable active plate 802 is installed inside the drying box 1. The fixed plate 801 and the active plate 802 divide the interior of the drying box 1 into a low-temperature chamber 101, a moistening chamber 102 and a high-temperature chamber 103. A fixed orifice plate 807 is installed on the fixed plate 801. A movable orifice plate 806 is installed on the active plate 802. The movable orifice plate 806 and the fixed orifice plate 807 are slidably matched. The heating component 3 includes a high-temperature pressure tank 301 and a low-temperature pressure tank 304 . The high-temperature pressure tank 301 is connected to the high-temperature chamber 103 , the low-temperature pressure tank 304 is connected to the low-temperature chamber 101 , the steam tank 4 is connected to the moisturizing chamber 102 , and a moisture sensor 9 is installed in the drying box 1 .

[0041] Specifically, the cylinder 7 is installed inside the moisturizing chamber 102 , and the cylinder 7 is connected to the active plate 802 via a push-pull rod 810 .

[0042] Specifically, the low-temperature pressure tank 304 is connected to the low-temperature chamber 101 through a low-temperature branch pipe 305, and the high-temperature pressure tank 301 is connected to the high-temperature chamber 103 through a high-temperature branch pipe 302, and one of the heads on the high-temperature branch pipe 302 is located in the moisturizing chamber 102.

[0043] It should be noted that the present invention detects the fluidity of the slurry on the green porcelain belt through the moisture sensor 9 at the entrance of the drying box 1, that is, detects the water content of the slurry, controls the cavity space of the low-temperature chamber 101 and the steam input amount of the moistening chamber 102 according to the fluidity of the slurry, and adjusts the solvent removal time for slurries with different fluidities. The output ends of the high-temperature pressure tank 301 and the low-temperature pressure tank 304 are both equipped with control valves for controlling the air intake.

[0044] See also Figure 7 A connecting rod 808 is installed on the driven plate 803 , a slide groove 809 is opened inside the connecting rod 808 , a slider 811 is installed on the push-pull rod 810 , the slider 811 slides inside the slide groove 809 , an electromagnetic suction cup 812 is installed inside the slide groove 809 , and the electromagnetic suction cup 812 adsorbs the slider 811 .

[0045] It should be noted that when it is necessary to drive the active plate 802 and the driven plate 803 to move synchronously through the cylinder 7, the electromagnetic suction cup 812 is started, that is, the push-pull rod 810 is connected to the connecting rod 808 through the slider 811. At this time, the active plate 802 and the driven plate 803 can be driven to move synchronously through the cylinder 7; if it is necessary to drive the active plate 802 to move alone, the electromagnetic suction cup 812 can be closed, and the active plate 802 can be driven to move alone through the cylinder 7.

[0046] See also Figure 7 A sealing frame 804 is installed on the driven plate 803 , a moisture absorbing block 805 is installed on the active plate 802 , and the sealing frame 804 covers the moisture absorbing block 805 .

[0047] It should be noted that a low humidity environment helps the solvent evaporate. In a humid environment, the moisture in the air will slow down the evaporation rate of the ethanol inside the solvent.

[0048] The moisture absorbing block 805 is made of a strong water-absorbing material. When the fluidity of the slurry on the green porcelain belt is strong, the sealing frame 804 is separated from the sealing cover of the moisture absorbing block 805. At this time, the moisture absorbing block 805 is exposed in the low-temperature chamber 101, so that the moisture absorbing block 805 absorbs moisture in the air inside the low-temperature chamber 101, provides a low-humidity space for the low-temperature chamber 101, and accelerates the volatilization of ethanol in the solvent.

[0049] See also Figure 4-Figure 6 The fixed plate 801 and the active plate 802 are provided with sealing strips 813 , and the fixed plate 801 and the active plate 802 contact the top of the drying box 1 through the sealing strips 813 thereon.

[0050] It should be noted that the fixed plate 801 and the active plate 802 seal and separate the low-temperature chamber 101 , the moistening chamber 102 and the high-temperature chamber 103 through the sealing strip 813 .

[0051] See also Figure 2-Figure 3 A plurality of multi-stage heating plates 6 are installed at the bottom of the drying box 1 , and exhaust fans 5 are installed on both the low-temperature chamber 101 and the high-temperature chamber 103 .

[0052] It should be noted that the temperature of the multi-stage heating plate 6 increases in steps. The multi-stage heating plate 6 is arranged in five groups, with two groups inside the low-temperature chamber 101 and the high-temperature chamber 103, and one group inside the moisturizing chamber 102, so as to reduce the influence of the temperature difference between the low-temperature chamber 101 and the high-temperature chamber 103 on the drying of the green porcelain tape.

[0053] The implementation principle of the present invention is: When in use, the green porcelain tape after casting is placed in the drying box 1, and the conveying device drives the green porcelain tape through the low-temperature chamber 101, the moistening chamber 102 and the high-temperature chamber 103 in sequence. During this process, the moisture sensor 9 at the entrance of the drying box 1 detects the fluidity of the slurry on the green porcelain tape, that is, detects the water content of the slurry.

[0054] When the fluidity of the slurry on the green porcelain belt is low, that is, the amount of solvent inside the slurry is small, the moisture sensor 9 controls the cylinder 7 to extend, see Figure 7 , the cylinder 7 drives the active plate 802 to move from the moistening chamber 102 to the low temperature chamber 101 through the push-pull rod 810. At the same time, the slider 811 on the active plate 802 drives the connecting rod 808 and the driven plate 803 to move. At this time, the active plate 802 and the driven plate 803 move synchronously toward the low temperature chamber 101. Figure 4 When the cylinder 7 drives the active plate 802 to cross one of the low-temperature branch pipes 305 and stops, the cavity space of the low-temperature chamber 101 is reduced, and the cavity space of the moisturizing chamber 102 is increased; in the process of the cylinder 7 driving the active plate 802 and the driven plate 803 to move, the movable orifice plate 806 on the active plate 802 moves relative to the fixed orifice plate 807, and the through holes on the movable orifice plate 806 gradually overlap with the through holes on the fixed orifice plate 807, and the steam output of the moisturizing chamber 102 increases.

[0055] When the raw porcelain belt passes through the low-temperature chamber 101, the cavity space of the low-temperature chamber 101 is reduced, and the time for the raw porcelain belt to pass through the low-temperature chamber 101 is reduced. While removing the solvent inside the raw porcelain belt, it is also possible to prevent the slurry with low fluidity on the raw porcelain belt from being in the low-temperature chamber 101 for a long time, which may cause the slurry to dry excessively and crack. At the same time, since the low-temperature branch pipe 305 blows dry hot air into the low-temperature chamber 101, a low-humidity volatile environment is provided while removing the solvent inside the raw porcelain belt; when the raw porcelain belt passes through the moisturizing chamber 102, the steam tank 4 injects steam into the moisturizing chamber 102. Since the high-temperature branch pipe 302 and the low-temperature branch pipe 305 are both located inside the moisturizing chamber 102, the hot air from the high-temperature branch pipe 302 and the low-temperature branch pipe 305 enters the moisturizing chamber. The steam is mixed and heated in the chamber 102, so that the temperature of the steam and hot air in the moistening chamber 102 is balanced between the temperature of the low-temperature chamber 101 and the high-temperature chamber 103. At this time, the steam and hot air in the moistening chamber 102 are blown to the green porcelain belt through the through holes on the fixed orifice plate 807 and the movable orifice plate 806, so that the green porcelain belt is gradually heated, and the influence of the temperature difference between the low-temperature chamber 101 and the high-temperature chamber 103 on the green porcelain belt is reduced. At the same time, the high-humidity steam can improve the fluidity of the slurry on the green porcelain belt, accelerate the flow of the slurry, and smooth the fine cracks caused by the volatilization of the solvent from the inside of the green porcelain belt; when the green porcelain belt passes through the high-temperature chamber 103, the high-temperature pressure tank 301 heats the green porcelain belt inside the high-temperature chamber 103 through the high-temperature branch pipe 302 to dry it. (Since the low-temperature branch pipe 305 blows dry hot air to the low-temperature chamber 101, it provides a low-humidity volatilization environment while removing the solvent inside the green porcelain belt. The solvent volatilization and diffusion from the inside of the green porcelain belt will easily cause fine cracks on the green porcelain belt).

[0056] When the fluidity of the slurry on the green porcelain belt is strong, that is, the amount of solvent inside the slurry is large, the moisture sensor 9 controls the cylinder 7 to retract, see Figure 7 , the electromagnetic suction cup 812 is closed, and as the cylinder 7 drives the active plate 802 to move toward the moistening chamber 102, the push-pull rod 810 drives the slider 811 to slide along the slide groove 809, so that the active plate 802 is separated from the driven plate 803. At this time, the sealing frame 804 on the driven plate 803 is separated from the seal of the moisture absorption block 805. When the active plate 802 returns to its previous position, the cylinder 7 is closed. Figure 4 During this process, the space of the low-temperature chamber 101 increases, and the space of the moisturizing chamber 102 decreases. At the same time, when the cylinder 7 drives the active plate 802 to move, the movable orifice plate 806 on the active plate 802 moves relative to the fixed orifice plate 807, so that the through holes on the movable orifice plate 806 and the through holes on the fixed orifice plate 807 are gradually staggered, and the steam output of the moisturizing chamber 102 is reduced.

[0057] When the raw porcelain belt passes through the low-temperature chamber 101, the cavity space of the low-temperature chamber 101 increases, and the time for the raw porcelain belt to pass through the low-temperature chamber 101 increases. Since the amount of solvent in the slurry is large, the time for the raw porcelain belt to pass through the low-temperature chamber 101 increases, thereby completely removing the solvent inside the raw porcelain belt. At the same time, the moisture absorption block 805 can absorb the moisture inside the low-temperature chamber 101, providing a drier environment for the low-temperature chamber 101, and cooperate with the dry hot air of the low-temperature branch pipe 305 to remove the moisture in the slurry while increasing the volatility of ethanol in the solvent; when the raw porcelain belt passes through the moistening chamber 102, due to the through holes on the movable orifice plate 806 and the fixed orifice plate The through holes on 807 are staggered, and the steam output of the moisturizing chamber 102 is reduced or stopped. At the same time, due to the strong fluidity of the slurry, the slurry can automatically flow to smooth out the fine cracks caused by volatilization inside the raw porcelain tape, and the moisturizing chamber 102 does not need to increase the fluidity of the slurry through steam; the multi-stage heating plate 6 is started, and the multi-stage heating plate 6 with step-by-step heating can gradually heat the raw porcelain tape to reduce the impact of the temperature difference between the low-temperature chamber 101 and the high-temperature chamber 103 on the raw porcelain tape; when the raw porcelain tape passes through the high-temperature chamber 103, the high-temperature pressure tank 301 heats the raw porcelain tape inside the high-temperature chamber 103 through the high-temperature branch pipe 302 to dry it.

[0058] While drying the green porcelain tape, the exhaust fan 5 is started, which accelerates the flow of hot air inside the low-temperature chamber 101 and the high-temperature chamber 103, so that the exhaust fan 5 can quickly discharge the solvent vapor volatilized from the green porcelain tape during the drying process in the low-temperature chamber 101, thereby preventing the vapor from condensing on the green porcelain tape and causing defects.

[0059] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for preparing a high-purity alumina ceramic green tape, characterized in that: The specific steps include: Step S1: adding ceramic powder into a ball mill, adding a dispersant, deionized water, a binder, a plasticizer and a solvent according to the proportion of the powder, mixing evenly and obtaining a mixture A; Step S2: adding a defoaming agent and a film-forming aid to the mixture A step by step, and continuing to ball mill with a planetary ball mill to obtain a mixture B; then placing the mixture B in a vacuum stirring tank for degassing to obtain a ceramic slurry; Step S3: heating, stirring and keeping the ceramic slurry warm, using the PET film tape as a tape-casting substrate, and tape-casting the treated ceramic slurry to obtain a green ceramic tape; Step S4: The green porcelain tape after tape casting is placed in a drying box (1), and a conveying device drives the green porcelain tape to pass through a low-temperature chamber (101), a moistening chamber (102), and a high-temperature chamber (103) in sequence. During this process, a moisture sensor (9) at the entrance of the drying box (1) detects the fluidity of the slurry on the green porcelain tape, and a multi-stage heating plate (6) inside the drying box (1) assists in heating the green porcelain tape.

2. The method for preparing a high-purity alumina ceramic green tape according to claim 1, characterized in that: The step S4 specifically comprises the following steps: Step S401: When the fluidity of the slurry on the green porcelain belt is low, the moisture sensor (9) controls the cylinder (7) to extend, and the cylinder (7) drives the active plate (802) to move from the moistening chamber (102) to the low-temperature chamber (101) through the push-pull rod (810), and the slider (811) on the active plate (802) drives the connecting rod (808) and the driven plate (803) to move. When the cylinder (7) drives the active plate (802) to pass over one of the low-temperature branch pipes (305), it stops. At this time, the cavity space of the low-temperature chamber (101) is reduced, and the cavity space of the moistening chamber (102) is increased; Step S402: When the cylinder (7) drives the active plate (802) and the driven plate (803) to move, the movable orifice plate (806) on the active plate (802) moves relative to the fixed orifice plate (807), and the through holes on the movable orifice plate (806) gradually overlap with the through holes on the fixed orifice plate (807); Step S403: when the green porcelain tape passes through the low-temperature chamber (101), the time for the green porcelain tape to pass through the low-temperature chamber (101) is reduced due to the reduction in the cavity space of the low-temperature chamber (101). At the same time, the low-temperature branch pipe (305) blows dry hot air into the low-temperature chamber (101), thereby providing a low-humidity volatilization environment and removing the solvent inside the green porcelain tape; Step S404: when the green porcelain belt passes through the moistening chamber (102), the steam tank (4) injects steam into the moistening chamber (102). Since the high-temperature branch pipe (302) and the low-temperature branch pipe (305) are both located inside the moistening chamber (102), the hot air from the high-temperature branch pipe (302) and the low-temperature branch pipe (305) are introduced into the moistening chamber (102) to mix and heat the steam, so that the temperature of the steam and hot air inside the moistening chamber (102) is balanced between the temperature of the low-temperature chamber (101) and the temperature of the high-temperature chamber (103). At this time, the steam and hot air inside the moistening chamber (102) are blown toward the green porcelain belt through the through holes on the fixed orifice plate (807) and the movable orifice plate (806); Step S405: When the green porcelain tape passes through the high-temperature chamber (103), the high-temperature pressure tank (301) heats the green porcelain tape inside the high-temperature chamber (103) through the high-temperature branch pipe (302) to dry it.

3. The method for preparing a high-purity alumina ceramic green tape according to claim 1, characterized in that: The step S4 specifically comprises the following steps: Step S411: When the fluidity of the slurry on the green porcelain belt is relatively strong, the moisture sensor (9) controls the cylinder (7) to retract. As the cylinder (7) drives the active plate (802) to move toward the moistening chamber (102), the push-pull rod (810) drives the slider (811) to slide along the slide groove (809), so that the active plate (802) and the driven plate (803) are separated. When the active plate (802) returns to its previous position, the cylinder (7) is closed. During this process, the space of the low-temperature chamber (101) increases, and the space of the moistening chamber (102) decreases. Step S412: when the cylinder (7) drives the active plate (802) to move, the movable orifice plate (806) on the active plate (802) moves relative to the fixed orifice plate (807), so that the through holes on the movable orifice plate (806) and the through holes on the fixed orifice plate (807) gradually stagger, and the steam output of the moisturizing chamber (102) decreases; Step S413: when the green porcelain tape passes through the low-temperature chamber (101), the cavity space of the low-temperature chamber (101) increases, the time for the green porcelain tape to pass through the low-temperature chamber (101) increases, and at the same time, the moisture absorption block (805) can absorb moisture inside the low-temperature chamber (101); Step S414: When the raw porcelain tape passes through the moistening chamber (102), the slurry has high fluidity and can automatically flow to smooth out the fine cracks caused by volatilization inside the raw porcelain tape. The moistening chamber (102) does not need to use steam to increase the fluidity of the slurry. The multi-stage heating plate (6) is started, and the multi-stage heating plate (6) with stepped heating gradually heats the raw porcelain tape.

4. The method for preparing a high-purity alumina ceramic green tape according to claim 2, characterized in that: An adjusting component (8) is installed in the drying box (1), a heating component (3) is installed on the drying box (1), and a heating component (3) and a steam tank (4) are installed on the bracket (2); The regulating assembly (8) comprises a fixed plate (801) and an active plate (802); the fixed plate (801) is fixedly mounted in the drying box (1); a movable active plate (802) is mounted inside the drying box (1); the fixed plate (801) and the active plate (802) divide the interior of the drying box (1) into a low-temperature chamber (101), a moistening chamber (102), and a high-temperature chamber (103); a fixed orifice plate (807) is mounted on the fixed plate (801); a movable orifice plate (806) is mounted on the active plate (802); and the movable orifice plate (806) and the fixed orifice plate (807) are slidably matched; The heating component (3) comprises a high-temperature pressure tank (301) and a low-temperature pressure tank (304); the high-temperature pressure tank (301) is connected to the high-temperature chamber (103); the low-temperature pressure tank (304) is connected to the low-temperature chamber (101); the steam tank (4) is connected to the moisturizing chamber (102); and a moisture sensor (9) is installed in the drying box (1).

5. The method for preparing a high-purity alumina ceramic green tape according to claim 4, characterized in that: A cylinder (7) is installed inside the moisturizing chamber (102), and the cylinder (7) is connected to the active plate (802) via a push-pull rod (810). A plurality of multi-stage heating plates (6) are installed at the bottom of the drying box (1), and exhaust fans (5) are installed on both the low-temperature chamber (101) and the high-temperature chamber (103).

6. The method for preparing a high-purity alumina ceramic green tape according to claim 5, characterized in that: A connecting rod (808) is installed on the driven plate (803), a sliding groove (809) is provided inside the connecting rod (808), a sliding block (811) is installed on the push-pull rod (810), the sliding block (811) is located inside the sliding groove (809) and slides, an electromagnetic suction cup (812) is installed inside the sliding groove (809), and the electromagnetic suction cup (812) adsorbs the sliding block (811).

7. The method for preparing a high-purity alumina ceramic green tape according to claim 6, characterized in that: A sealing frame (804) is installed on the driven plate (803), a moisture absorbing block (805) is installed on the active plate (802), and the sealing frame (804) covers the moisture absorbing block (805).

8. The method for preparing a high-purity alumina ceramic green tape according to claim 4, characterized in that: A sealing strip (813) is installed on the fixed plate (801) and the active plate (802), and the fixed plate (801) and the active plate (802) contact the top of the drying box (1) through the sealing strip (813) thereon.

9. The method for preparing a high-purity alumina ceramic green tape according to claim 4, characterized in that: The low-temperature pressure tank (304) is connected to the low-temperature chamber (101) via a low-temperature branch pipe (305), and the high-temperature pressure tank (301) is connected to the high-temperature chamber (103) via a high-temperature branch pipe (302), and one of the heads on the high-temperature branch pipe (302) is located in the moisturizing chamber (102).

10. The method for preparing a high-purity alumina ceramic green tape according to claim 1, characterized in that: The solvent is a mixture of anhydrous ethanol, butanone and n-butanol.

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