Multilayer ceramic atomizing core and preparation method thereof

Abstract

The invention relates to a multilayer ceramic atomizing core and a preparation method thereof. The multilayer ceramic atomizing core comprises an oil guide layer, an oil locking layer and an atomizing layer, a containing groove is formed in the lower end of the oil guide layer, the oil locking layer and the atomizing layer are sequentially arranged in the containing groove from top to bottom, the porosity of the oil guide layer is larger than that of the atomizing layer, and the porosity of the atomizing layer is larger than that of the oil locking layer; raw materials of the oil guide layer, the oil locking layer and the atomization layer respectively comprise at least one of diatomite, silicon dioxide, a pore forming agent, glass powder, paraffin and oleic acid, the oil locking layer further comprises at least one of corundum and silicon carbide, and the porosity of the oil locking layer is the lowest. The atomization layer and the oil locking layer are wrapped by the oil guide layer, so that cracking at a joint seam can be avoided. And the porosity is set to be greater than the porosity of the oil locking layer and less than the porosity of the oil guiding layer, so that the atomization effect is ensured. And corundum and silicon carbide are added into the oil locking layer, so that the change of the porosity is influenced, and meanwhile, the structural stability and the atomization efficiency of the atomization core are improved.

Description

Technical Field

[0001] This invention relates to the field of electronic cigarette technology, and in particular to a multilayer ceramic atomizing core and its preparation method. Background Technology

[0002] The atomizer core of an electronic atomizing device is a core component, playing a crucial role in the aerosol flavor, vapor production, and other performance aspects of the device. Existing technology discloses a ceramic atomizer core and its preparation method (application number 202110784612.4). This ceramic atomizer core uses only one material as its matrix, and the atomization effect is controlled by adjusting the thickness of the wicking area and the resistance of the heating wire. Excessive matrix porosity can lead to incomplete atomization and leakage; insufficient porosity can result in slow wicking speeds and dry burning of the heating wire. Furthermore, the use of pore-forming agents to influence porosity often results in poor structural stability of the atomizer core.

[0003] Some ceramic atomizing cores also adopt a multi-layered structure design, such as a dual-hole three-layer ceramic atomizing core and electronic cigarette with application number 202320126927.4. By setting up a multi-layered structure, however, due to differences in the types and ratios of ingredients and density, different shrinkage rates will occur, which often leads to inconsistent shrinkage rates between layers. This will cause stress between layers, resulting in delamination and affecting the atomization effect and product reliability. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a multi-layer ceramic atomizing core. By placing the wicking layer on the outermost layer, encapsulating the atomizing layer and the oil-locking layer, cracking at the joints due to different shrinkage rates of the layers can be effectively prevented during sintering. Furthermore, the wicking layer has the highest porosity, resulting in faster wicking speed. The middle oil-locking layer has the lowest porosity, slowing down the wicking speed and preventing e-liquid from entering the atomizing layer too quickly, thus preventing incomplete atomization. The bottom layer is the atomizing layer, ensuring the atomization effect of the core. Moreover, the oil-locking layer, by adding corundum and silicon carbide to influence porosity, also improves the structural stability and atomization efficiency of the atomizing core.

[0005] Another objective of this invention is to provide a method for preparing a multilayer ceramic atomizing core, which is easy to control, has high production efficiency, and is conducive to large-scale production.

[0006] The objective of this invention is achieved through the following technical solution: A multi-layer ceramic atomizing core includes an oil guiding layer, an oil locking layer, and an atomizing layer. A receiving groove is formed at the lower end of the oil guiding layer. The oil locking layer and the atomizing layer are arranged sequentially from top to bottom in the receiving groove. The porosity of the oil guiding layer is greater than that of the atomizing layer, and the porosity of the atomizing layer is greater than that of the oil locking layer. The atomizing layer is provided with a heating wire.

[0007] Furthermore, the upper end face of the oil-locking layer is connected to the top wall of the receiving groove, the lower end face of the oil-locking layer is connected to the upper end face of the atomizing layer, and the peripheral sidewalls of the oil-locking layer and the atomizing layer are connected to the peripheral inner wall of the receiving groove. That is, the oil-guiding layer is located on the outermost layer, wrapping the atomizing layer and the oil-locking layer.

[0008] The multi-layer ceramic atomizing core of this invention mainly comprises three parts: an oil guiding layer, an oil locking layer, and an atomizing layer. By sequentially placing the oil locking layer and the atomizing layer in the receiving groove of the oil guiding layer from top to bottom, the oil guiding layer wraps around the atomizing layer and the oil locking layer, covering the joint between the inner wall of the oil guiding layer and the oil locking layer, as well as the joint between the oil locking layer and the atomizing layer. This not only satisfies the speed at which the ceramic atomizing core draws oil from the oil tank, but also avoids cracking at the joint due to different shrinkage rates of each layer. In addition, the outermost wicking layer has high porosity, which quickly absorbs e-liquid from the oil tank to ensure a sufficient supply of e-liquid and prevent dry burning due to slow absorption. The oil-locking layer between the wicking layer and the atomizing layer has low porosity, which slows down the transfer speed of e-liquid from the wicking layer to the atomizing layer and prevents e-liquid from entering the atomizing layer too quickly, which would prevent the heating coil from completely atomizing the e-liquid. The bottom atomizing layer has medium porosity between the two, which can smoothly receive the e-liquid transferred by the oil-locking layer and work with the heating efficiency of the heating coil to ensure that the e-liquid is fully atomized. At the same time, it avoids the influence of the low porosity of the oil-locking layer and ensures the stability of atomization. Furthermore, since the e-liquid is transferred through surface contact between the wicking layer and the locking layer, and between the locking layer and the atomizing layer, the flow of e-liquid mainly relies on the pressure difference generated during atomization. Specifically, during atomization, the heating coil heats the e-liquid within the atomizing layer, causing it to evaporate and creating a localized low-pressure zone. The pressure difference between the wicking layer (high porosity, ample e-liquid) and the atomizing layer (low-pressure zone) propels the e-liquid through the locking layer to the atomizing layer. This driving method avoids the problem of slow e-liquid absorption in traditional single-material low-porosity ceramic atomizing cores. Traditional single-material ceramics rely on capillary action for e-liquid absorption, and low porosity leads to insufficient absorption speed. In other words, the three-layer structure of the wicking layer, locking layer, and atomizing layer is driven by pressure difference, which avoids the problem of slow e-liquid absorption from the tank when the porosity of the ceramic atomizing core made of a single material is too small, as well as the risk of incomplete atomization and leakage when the porosity is too large.

[0009] Furthermore, the raw materials for the oil guiding layer, the oil locking layer, and the atomizing layer respectively include at least one of diatomaceous earth, silica, pore-forming agent, glass powder, paraffin wax, and oleic acid, wherein the oil locking layer also includes at least one of corundum and silicon carbide, and the oil locking layer has the lowest porosity.

[0010] This invention relates to a multilayer ceramic atomizing core prepared by adding diatomaceous earth, silica, a pore-forming agent, glass powder, paraffin wax, and oleic acid to the raw materials for preparing the oil-guiding layer, oil-locking layer, and atomizing layer. This multilayer ceramic atomizing core exhibits advantages such as uniform pore distribution, high atomization efficiency, and good compressive strength. The diatomaceous earth and silica used, under the action of the pore-forming agent, form voids, ensuring the porosity of the product. This results in a sintered ceramic atomizing core with good strength, high porosity, and small, uniformly distributed pore size. The addition of glass powder promotes the sintering reaction by forming a liquid phase during high-temperature sintering, lowering the sintering temperature. Upon cooling, a new solid phase is formed, promoting particle rearrangement and mass transfer. The liquid phase generated at a lower temperature facilitates sintering and simultaneously promotes the densification of the ceramic matrix. The addition of oleic acid ensures low moisture content in the powder, reducing powder agglomeration during ball milling to prevent clumping, improving powder dispersibility and fineness, increasing surface activity, and enhancing slurry flowability when mixed with paraffin. Furthermore, compared to the wicking and atomizing layers, the oil-locking layer also incorporates silicon carbide and corundum. While corundum and silicon carbide influence the porosity of the oil-locking layer, silicon carbide's stable chemical properties and high thermal conductivity improve the thermal conductivity of the oil-locking layer. Contact between the e-liquid and the oil-locking layer preheats the e-liquid, improving atomization efficiency and accelerating heat and oil conduction. Corundum enhances the bonding between multi-layer ceramic atomizing core particles, thereby improving the structural stability and strength of the multi-layer ceramic atomizing core. Through formula adjustments and structural improvements, the structural stability of the multi-layer ceramic atomizing core is enhanced while maintaining atomization efficiency, resulting in a multi-layer ceramic atomizing core matrix with better strength, consistency, and superior overall performance.

[0011] Furthermore, the oil-guiding layer comprises the following components in the following weight ratio: diatomaceous earth 45-75: silica 25-55: pore-forming agent 10-35: glass powder 10-35: paraffin wax 20-40: oleic acid 2-5.

[0012] Furthermore, the oil-locking layer comprises the following components in the following weight ratio: diatomaceous earth 20-50: silicon dioxide 35-65: pore-forming agent 10-35: glass powder 10-35: corundum 1-10: silicon carbide 5-20: paraffin wax 20-40: oleic acid 2-5.

[0013] Furthermore, the atomizing layer comprises the following components in the following weight ratio: diatomaceous earth 35-65: silica 35-65: pore-forming agent 10-35: glass powder 10-35: paraffin wax 20-40: oleic acid 2-5.

[0014] This invention employs a ceramic matrix for the atomizing layer, a ceramic matrix for the oil-locking layer, and a ceramic matrix for the oil-guiding layer, all made from the aforementioned ceramic materials. The composition and proportions of each ceramic matrix layer are somewhat different, resulting in variations in porosity, pore size, and thermal conductivity of each layer. This allows for adjustment of the porosity, pore size, and oil-guiding velocity of each layer of the ceramic atomizing core, avoiding the influence of e-liquid transfer in the oil-locking layer. By simply adjusting the composition and proportions of the oil-locking layer, and by adding corundum and silicon carbide, the porosity, thermal conductivity, and compressive strength can be influenced, thereby optimizing the atomization effect.

[0015] Furthermore, the glass powder is low-temperature glass powder with a mesh size of 2000-5000 mesh.

[0016] Furthermore, the diatomaceous earth has a mesh size of 200-600 mesh; the silicon dioxide has a mesh size of 200-600 mesh; the glass powder has a mesh size of 2000-5000 mesh; the corundum has a mesh size of 200-600 mesh; and the silicon carbide has a mesh size of 200-600 mesh.

[0017] Furthermore, the pore size of the wicking layer is larger than that of the atomizing layer, and the pore size of the atomizing layer is larger than that of the oil-locking layer. The wicking layer has the largest pore size and porosity, forming a coarse channel. Under the combined action of capillary force and subsequent atomization pressure difference, the e-liquid quickly fills the coarse channel of the wicking layer, completing the oil storage. The oil-locking layer has the smallest pore size and porosity, forming a fine channel. The high resistance generated significantly reduces the flow rate of the e-liquid, keeping the e-liquid transfer rate within a range that matches the heating efficiency of the atomizing layer, balancing the oil supply and atomization rhythm. The porosity and pore size of the atomizing layer are between the two, forming a medium channel. After the e-liquid, slowed down by the oil-locking layer, enters the atomizing layer, the resistance of the medium-sized channel is moderately reduced, allowing the e-liquid to be evenly dispersed inside the atomizing layer and fully contact the heating coil.

[0018] Furthermore, the pore-forming agent is at least one selected from polyethylene, methylcellulose, graphite powder, starch, walnut powder, carbon powder, and PMMA. The present invention uses the above-mentioned pore-forming agent, which can promote an increase in porosity, does not react with other components, is easily removed during heating and sintering, and leaves no harmful residues in the matrix after removal, thus ensuring the structural stability of the matrix.

[0019] Furthermore, the oil guiding layer is in the shape of a cuboid, annular, or rectangular annular. The appropriate shape can be selected based on the available space, oil tank, and assembly requirements of the corresponding equipment.

[0020] Furthermore, the heating wire is made of at least one of nickel-chromium alloy, iron-chromium-aluminum alloy, stainless steel, or titanium alloy. This allows the heating wire to quickly generate stable heat when energized.

[0021] Another objective of this invention is achieved through the following technical solution: a method for preparing the above-mentioned multilayer ceramic atomizing core, comprising the following steps:

[0022] (1) According to the weight parts, diatomaceous earth, silica, pore-forming agent, glass powder and oleic acid are ball-milled and mixed evenly to obtain atomized layer ceramic material. The ball-milled ceramic material is dried at a temperature of 80-125℃. At the same time, paraffin is heated to 90-125℃ to melt it. Then, the dried atomized layer ceramic material is added while stirring. After the addition is completed, stirring is continued for 2-4 hours to obtain atomized layer ceramic slurry for later use.

[0023] (2) According to the weight parts, diatomaceous earth, silica, pore-forming agent, glass powder, oleic acid, silicon carbide and corundum are ball-milled and mixed evenly to obtain oil-locking ceramic material. The ball-milled ceramic material is dried at a temperature of 80-125℃. At the same time, the paraffin is heated to 90-125℃ to melt it. Then the dried oil-locking ceramic material is added while stirring. After the addition is completed, stirring is continued for 2-4 hours to obtain oil-locking ceramic slurry for later use.

[0024] (3) According to the weight parts, diatomaceous earth, silica, pore-forming agent, glass powder and oleic acid are ball-milled and mixed evenly to obtain oil-conducting layer ceramic material. The ball-milled ceramic material is dried at a temperature of 80-125℃. At the same time, the paraffin is heated to 90-125℃ to melt it. Then the dried oil-conducting layer ceramic material is added while stirring. After the addition is completed, stirring is continued for 2-4 hours to obtain oil-conducting layer ceramic slurry for later use.

[0025] (4) First molding: The heating wire is placed in the hot press mold, and then the atomized layer ceramic slurry is injected into the hot press mold for hot press molding. Under the conditions of temperature of 70-90℃ and pressure of 4-5MPa, the atomized layer ceramic matrix is ​​obtained for later use.

[0026] (5) Second molding: The atomized layer ceramic substrate obtained in step (4) is placed in a hot press mold, and the oil-locking layer ceramic slurry is injected for a second hot press molding. Under the conditions of temperature of 70-100℃ and pressure of 4-7MPa, the atomized layer and oil-locking layer combined ceramic substrate is obtained for later use.

[0027] (6) Third molding: Place the ceramic matrix of the atomizing layer and the oil-locking layer obtained in step (5) into a hot press mold, inject the oil-guiding layer ceramic slurry for the third hot press molding, and make a multi-layer ceramic atomizing core matrix under the conditions of temperature of 70-100℃ and pressure of 4-7MPa for later use.

[0028] (7) Debinding: Place the multilayer ceramic atomizing core substrate obtained in step (6) into a debinding furnace, use air as the debinding atmosphere, and debind at 400-800℃ for 2-6 hours.

[0029] (8) Sintering: The multilayer ceramic atomizing core substrate obtained in step (7) is transferred to a sintering furnace, air is used as the sintering atmosphere, and sintering is carried out according to the sintering curve to produce a multilayer ceramic atomizing core.

[0030] The ceramic atomizing core of this invention is prepared by the above method. The preparation method is easy to control, has high production efficiency, and is conducive to large-scale production. The ceramic atomizing core prepared by the above method has a novel structure, fast oil absorption, strong compressive strength, and will not crack or delaminate due to different shrinkage rates of each layer.

[0031] Furthermore, in step (8), the sintering curve includes the following steps:

[0032] S1. Heating stage: Increase the temperature from room temperature to 400-500℃ at a rate of 3-8℃ / minute, and keep it at 400-500℃ for 2-3 hours.

[0033] S2, Intermediate heat preservation stage: Heat to 600-700℃ and keep warm for 2-4 hours;

[0034] S3, High-temperature sintering stage: Continue to raise the temperature to 800-1000℃ and hold for 4-6 hours;

[0035] S4. Cooling stage: After sintering, the material is naturally cooled to room temperature to obtain a multi-layer ceramic atomizing core.

[0036] This invention uses the aforementioned sintering curve to sinter the multilayer ceramic atomizing core matrix obtained in step (7). In step S2, at 600-700℃, the ceramic particles begin to diffuse on the surface, and the particles initially bond to form a continuous skeleton, rapidly densifying. Simultaneously, the pore-forming agent reserved in the matrix begins to decompose, initially forming a porous structure. In step S3, at 800-1000℃, the particles enter the volume diffusion stage, and the skeleton is further densified to improve mechanical strength. At the same time, this temperature can effectively reduce thermal stress, compensate for shrinkage, and reduce pore closure caused by local deformation, thus obtaining a multilayer ceramic atomizing core with uniformly distributed pores.

[0037] The beneficial effects of this invention are as follows:

[0038] (1) The multi-layer ceramic atomizing core of the present invention arranges the oil-locking layer and the atomizing layer sequentially from top to bottom in the receiving groove of the oil-guiding layer, so that the oil-guiding layer covers the joint between the inner wall of the oil-guiding layer and the oil-locking layer, as well as the joint between the oil-locking layer and the atomizing layer. This can effectively prevent cracking at the joint due to different shrinkage rates of each layer. Moreover, the outermost oil-guiding layer has the largest porosity, which makes the atomizing core absorb oil faster. The middle oil-locking layer has the smallest porosity, which can slow down the oil guiding speed and prevent the e-liquid from entering the atomizing layer too quickly, resulting in incomplete atomization. The bottom atomizing layer has a medium porosity between the two, which can smoothly receive the e-liquid transferred by the oil-locking layer and cooperate with the heating efficiency of the heating wire to ensure that the e-liquid is fully atomized. The oil-guiding layer, the oil-locking layer and the atomizing layer cooperate with each other to ensure atomization stability and greatly improve the atomization effect.

[0039] (2) The multi-layer ceramic atomizing core of the present invention has surface contact between the oil guiding layer, the oil locking layer and the atomizing layer. The flow of e-liquid mainly depends on the pressure difference generated during atomization. This can avoid the problem of slow oil absorption speed from the oil tank when the porosity of the ceramic atomizing core made of a single material is too small, as well as the situation of incomplete atomization and leakage risk when the porosity is too large.

[0040] (3) The multi-layer ceramic atomizing core of the present invention, which is made by mixing diatomaceous earth, silica, pore-forming agent, glass powder, paraffin and oleic acid, has the advantages of uniform pore distribution, high atomization efficiency and good compressive strength. In addition, silicon carbide and corundum are added to the oil-locking layer. While the porosity of the oil-locking layer is affected by the corundum and silicon carbide, the structural stability and thermal conductivity of the atomizing core are also improved.

[0041] (4) The preparation method is easy to control, has high production efficiency, and is conducive to large-scale production. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the three-dimensional structure of a multi-layer ceramic atomizing core.

[0043] Figure 2 This is a top view of the multi-layer ceramic atomizing core.

[0044] Figure 3 This is a longitudinal cross-sectional view of the multi-layer ceramic atomizing core.

[0045] Figure 4 This is a schematic diagram showing the exploded structure of a multi-layer ceramic atomizing core.

[0046] Figure 5 This is a microscopic morphology diagram of Example 6.

[0047] Figure 6 The image shown is of the product in Comparative Example 1.

[0048] The attached diagram is labeled as follows: 1. Oil guiding layer; 2. Oil locking layer; 3. Atomizing layer; 4. Heating wire. Detailed Implementation

[0049] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention.

[0050] like Figure 1-6 As shown, in one embodiment of the present invention, a multi-layer ceramic atomizing core includes an oil-guiding layer 1, an oil-locking layer 2, and an atomizing layer 3. The lower end of the oil-guiding layer 1 has a receiving groove. The oil-locking layer 2 and the atomizing layer 3 are arranged sequentially from top to bottom in the receiving groove. The porosity of the oil-guiding layer 1 is greater than that of the atomizing layer 3, and the porosity of the atomizing layer 3 is greater than that of the oil-locking layer 2. The atomizing layer 3 is provided with a heating wire 4.

[0051] Furthermore, the upper end face of the oil-locking layer 2 is connected to the top wall of the receiving groove, the lower end face of the oil-locking layer 2 is connected to the upper end face of the atomizing layer 3, and the peripheral side walls of the oil-locking layer 2 and the atomizing layer 3 are connected to the peripheral inner wall of the receiving groove. That is, the oil-guiding layer 1 is located on the outermost layer, wrapping the atomizing layer 3 and the oil-locking layer 2.

[0052] In one embodiment of the present invention, the pore size of the oil guiding layer 1 is larger than the pore size of the atomizing layer 3, and the pore size of the atomizing layer 3 is larger than the pore size of the oil locking layer 2.

[0053] In some embodiments of the present invention, the oil guiding layer 1 is in the shape of a cuboid, annulus, or rectangular annulus. The shape can be selected according to the space, oil tank, and assembly requirements of the corresponding equipment.

[0054] In some embodiments of the present invention, the heating wire 4 is made of at least one of nickel-chromium alloy, iron-chromium-aluminum alloy, stainless steel, or titanium alloy. This allows the heating wire 4 to quickly generate stable heat when energized.

[0055] In some embodiments of the present invention, the raw materials of the oil guiding layer, the oil locking layer and the atomizing layer respectively include at least one of diatomaceous earth, silica, pore-forming agent, glass powder, paraffin wax and oleic acid, wherein the oil locking layer further includes at least one of corundum and silicon carbide, and the oil locking layer has the lowest porosity.

[0056] In some embodiments of the present invention, the oil-guiding layer comprises the following components in the following weight ratio: diatomaceous earth 45-75: silica 25-55: pore-forming agent 10-35: glass powder 10-35: paraffin wax 20-40: oleic acid 2-5.

[0057] Furthermore, the oil-locking layer comprises the following components in the following weight ratio: diatomaceous earth 20-50: silicon dioxide 35-65: pore-forming agent 10-35: glass powder 10-35: corundum 1-10: silicon carbide 5-20: paraffin wax 20-40: oleic acid 2-5.

[0058] Furthermore, the atomizing layer comprises the following components in the following weight ratio: diatomaceous earth 35-65: silica 35-65: pore-forming agent 10-35: glass powder 10-35: paraffin wax 20-40: oleic acid 2-5.

[0059] In some embodiments of the present invention, the pore-forming agent is at least one selected from polyethylene, methylcellulose, graphite powder, starch, walnut powder, carbon powder, and PMMA.

[0060] In some embodiments of the present invention, the glass powder is low-temperature glass powder with a mesh size of 2000-5000 mesh.

[0061] In some embodiments of the present invention, the diatomaceous earth has a mesh size of 200-600 mesh; the silicon dioxide has a mesh size of 200-600 mesh; the glass powder has a mesh size of 2000-5000 mesh; the corundum has a mesh size of 200-600 mesh; and the silicon carbide has a mesh size of 200-600 mesh.

[0062] In an embodiment of the present invention, a method for preparing a multilayer ceramic atomizing core includes the following steps:

[0063] (1) According to the weight parts, diatomaceous earth, silica, pore-forming agent, glass powder and oleic acid are ball-milled and mixed evenly to obtain atomized layer ceramic material. The ball-milled ceramic material is dried at a temperature of 80-125℃. At the same time, paraffin is heated to 90-125℃ to melt it. Then, the dried atomized layer ceramic material is added while stirring. After the addition is completed, stirring is continued for 2-4 hours to obtain atomized layer ceramic slurry for later use.

[0064] (2) According to the weight parts, diatomaceous earth, silica, pore-forming agent, glass powder, oleic acid, corundum and silicon carbide are ball-milled and mixed evenly to obtain oil-locking layer ceramic material. The ball-milled ceramic material is dried at a temperature of 80-125℃. At the same time, paraffin is heated to 90-125℃ to melt it. Then, the dried oil-locking layer ceramic material is added while stirring. After the addition is completed, stirring is continued for 2-4 hours to obtain oil-locking layer ceramic slurry for later use.

[0065] (3) According to the weight parts, diatomaceous earth, silica, pore-forming agent, glass powder and oleic acid are ball-milled and mixed evenly to obtain oil-conducting layer ceramic material. The ball-milled ceramic material is dried at a temperature of 80-125℃. At the same time, the paraffin is heated to 90-125℃ to melt it. Then the dried oil-conducting layer ceramic material is added while stirring. After the addition is completed, stirring is continued for 2-4 hours to obtain oil-conducting layer ceramic slurry for later use.

[0066] (4) First molding: The heating wire is placed in the hot press mold, and then the atomized layer ceramic slurry is injected into the hot press mold for hot press molding. Under the conditions of temperature of 70-90℃ and pressure of 4-5MPa, the atomized layer ceramic matrix is ​​obtained for later use.

[0067] (5) Second molding: The atomized layer ceramic substrate obtained in step (4) is placed in a hot press mold, and the oil-locking layer ceramic slurry is injected for a second hot press molding. Under the conditions of temperature of 70-100℃ and pressure of 4-7MPa, the atomized layer and oil-locking layer combined ceramic substrate is obtained for later use.

[0068] (6) Third molding: Place the ceramic matrix of the atomizing layer and the oil-locking layer obtained in step (5) into a hot press mold, inject the oil-guiding layer ceramic slurry for the third hot press molding, and make a multi-layer ceramic atomizing core matrix under the conditions of temperature of 70-100℃ and pressure of 4-7MPa for later use.

[0069] (7) Debinding: Place the multilayer ceramic atomizing core substrate obtained in step (6) into a debinding furnace, use air as the debinding atmosphere, and debind at 400-800℃ for 2-6 hours.

[0070] (8) Sintering: The multilayer ceramic atomizing core substrate obtained in step (7) is transferred to a sintering furnace, air is used as the sintering atmosphere, and sintering is carried out according to the sintering curve to produce a multilayer ceramic atomizing core.

[0071] In some embodiments of the present invention, step (8) includes the following steps:

[0072] S1. Heating stage: Increase the temperature from room temperature to 400-500℃ at a rate of 3-8℃ / minute, and keep it at 400-500℃ for 2-3 hours.

[0073] S2, Intermediate heat preservation stage: Heat to 600-700℃ and keep warm for 2-4 hours;

[0074] S3, High-temperature sintering stage: Continue to raise the temperature to 800-1000℃ and hold for 4-6 hours;

[0075] S4. Cooling stage: After sintering, the material is naturally cooled to room temperature to obtain a multi-layer ceramic atomizing core.

[0076] Example 1

[0077] like Figure 1-6 As shown in this embodiment, a multi-layer ceramic atomizing core includes an oil-guiding layer 1, an oil-locking layer 2, and an atomizing layer 3. A receiving groove is formed at the lower end of the oil-guiding layer 1. The oil-locking layer 2 and the atomizing layer 3 are sequentially disposed within the receiving groove from top to bottom. The porosity of the oil-guiding layer 1 is greater than that of the atomizing layer 3, and the porosity of the atomizing layer 3 is greater than that of the oil-locking layer 2. The atomizing layer 3 is provided with a heating wire 4. The heating wire 4 is made of nickel-chromium alloy.

[0078] Furthermore, the upper end face of the oil-locking layer is connected to the top wall of the receiving groove, the lower end face of the oil-locking layer is connected to the upper end face of the atomizing layer, and the peripheral sidewalls of the oil-locking layer and the atomizing layer are connected to the peripheral inner wall of the receiving groove. That is, the oil-guiding layer is located on the outermost layer, wrapping the atomizing layer and the oil-locking layer.

[0079] Furthermore, the oil-guiding layer comprises the following components in the following weight ratio: diatomaceous earth 60: silica 40: pore-forming agent 31: glass powder 19: paraffin wax 25: oleic acid 3.

[0080] Furthermore, the oil-locking layer comprises the following components in the following weight ratio: diatomaceous earth 34: silica 50: pore-forming agent 22: glass powder 28: corundum 8: silicon carbide 8: paraffin wax 8: oleic acid 3.

[0081] Furthermore, the atomizing layer comprises the following components in the following weight ratio: diatomaceous earth 50: silica 50: pore-forming agent 26: glass powder 24: paraffin wax 25: oleic acid 3.

[0082] Furthermore, the glass powder is low-temperature glass powder with a mesh size of 3000.

[0083] Furthermore, the diatomaceous earth has a mesh size of 400; the silicon dioxide has a mesh size of 400; the corundum has a mesh size of 400; and the silicon carbide has a mesh size of 400.

[0084] This embodiment also provides a method for preparing a multilayer ceramic atomizing core, including the following steps:

[0085] (1) According to the weight parts, diatomaceous earth, silica, pore-forming agent, glass powder and oleic acid are ball-milled and mixed evenly to obtain atomized layer ceramic material. The ball-milled ceramic material is dried at a temperature of 100℃. At the same time, paraffin is heated to 108℃ to melt it. Then the dried atomized layer ceramic material is added while stirring. After the addition is completed, stirring is continued for 3 hours to obtain atomized layer ceramic slurry for later use.

[0086] (2) According to the weight parts, diatomaceous earth, silica, pore-forming agent, glass powder, oleic acid, silicon carbide and corundum are ball-milled and mixed evenly to obtain oil-locking layer ceramic material. The ball-milled ceramic material is dried at a temperature of 100℃. At the same time, paraffin is heated to 108℃ to melt it. Then, the dried oil-locking layer ceramic material is added while stirring. After the addition is completed, stirring is continued for 3 hours to obtain oil-locking layer ceramic slurry for later use.

[0087] (3) According to the weight parts, diatomaceous earth, silica, pore-forming agent, glass powder and oleic acid are ball-milled and mixed evenly to obtain oil-conducting layer ceramic material. The ball-milled ceramic material is dried at a temperature of 100℃. At the same time, paraffin is heated to 108℃ to melt it. Then, the dried oil-conducting layer ceramic material is added while stirring. After the addition is completed, stirring is continued for 3 hours to obtain oil-conducting layer ceramic slurry for later use.

[0088] (4) First molding: The heating wire is placed in the hot press mold, and then the atomized layer ceramic slurry is injected into the hot press mold for hot press molding. Under the conditions of temperature of 80℃ and pressure of 4.5MPa, the atomized layer ceramic matrix is ​​obtained for later use.

[0089] (5) Second molding: The atomized layer ceramic substrate obtained in step (4) is placed in a hot press mold, and the oil-locking layer ceramic slurry is injected for a second hot press molding. Under the conditions of 85°C and 5.5MPa, the atomized layer and oil-locking layer combined ceramic substrate is obtained for later use.

[0090] (6) Third molding: The ceramic matrix of the atomizing layer and the oil-locking layer obtained in step (5) is placed in the hot press casting mold, and the oil-guiding layer ceramic slurry is injected for the third hot press casting. Under the conditions of temperature of 85℃ and pressure of 5.5MPa, a multi-layer ceramic atomizing core matrix is ​​made for later use.

[0091] (7) Debinding: The multilayer ceramic atomizing core substrate obtained in step (6) is placed in a debinding furnace, and air is used as the debinding atmosphere. Debinding is carried out at 600°C for 4 hours.

[0092] (8) Sintering: The multilayer ceramic atomizing core substrate obtained in step (7) is transferred to a sintering furnace, air is used as the sintering atmosphere, and sintering is carried out according to the sintering curve to produce a multilayer ceramic atomizing core.

[0093] Furthermore, in step (8), the sintering curve includes the following steps:

[0094] S1. Heating stage: The temperature is increased from room temperature to 450℃ at a rate of 5℃ / minute, and then held at 450℃ for 2.5 hours.

[0095] S2, Intermediate heat preservation stage: Heat up to 650℃ and keep warm for 3 hours;

[0096] S3, High-temperature sintering stage: Continue to heat to 900℃ and hold for 5 hours;

[0097] S4. Cooling stage: After sintering, the material is naturally cooled to room temperature to obtain a multi-layer ceramic atomizing core.

[0098] In Examples 2-6 of the present invention, the components and weight ratios of the oil guiding layer, oil locking layer and atomizing layer are different from those in Example 1, while the rest are the same as in Example 1.

[0099] The weights of each component of the oil guiding layer, oil locking layer, and atomizing layer in Examples 1-6 are shown in Table 1 below:

[0100] Table 1

[0101]

[0102]

[0103] Comparative Example 1

[0104] The difference between this comparative example and Example 6 above is that the atomizing ceramic core of this comparative example includes an oil-guiding layer, an oil-locking layer, and an atomizing layer arranged sequentially from top to bottom. The lower end face of the oil-guiding layer does not have a receiving groove, and its structure is a flat sheet. That is, the oil-guiding layer does not wrap the oil-locking layer and the atomizing layer. The lower end face of the oil-guiding layer is connected to the upper end face of the oil-locking layer, and the lower end face of the oil-locking layer is connected to the upper end face of the atomizing layer, forming a layered structure. The rest of the contents of this comparative example are the same as those of Example 6, and will not be repeated here.

[0105] Comparative Example 2

[0106] The difference between this comparative example and Example 6 above is that the atomizing ceramic core of this comparative example is formed by hot pressing of a single ceramic material in one step, with the same thickness as the ceramic atomizing core obtained in Example 6, and the structure is a single layer of ceramic material. The rest of the contents of this comparative example are the same as those of Example 6, and will not be repeated here.

[0107] Comparative Example 3

[0108] The difference between this comparative example and Example 6 above is that the atomizing ceramic core of this comparative example is made by hot pressing and casting a single ceramic material with an oil-locking layer, and has the same thickness as the ceramic atomizing core obtained in Example 6, with a single-layer ceramic material structure. The rest of the contents of this comparative example are the same as those of Example 6, and will not be repeated here.

[0109] Comparative Example 4

[0110] The difference between this comparative example and Example 6 above is that the atomizing ceramic core of this comparative example is made by hot pressing and casting a single ceramic material into an oil-guiding layer ceramic core in one piece. It has the same thickness as the ceramic atomizing core obtained in Example 6, and its structure is a single-layer ceramic material. The rest of the contents of this comparative example are the same as those of Example 6, and will not be repeated here.

[0111] Comparative Example 5

[0112] The difference between this comparative example and Example 6 above is that the oil-locking layer in this comparative example includes the following components in the following weight ratio: diatomaceous earth 42.85: silica 57.15: pore-forming agent 22: glass powder 28: paraffin wax 25: oleic acid 3. The rest of the contents of this comparative example are the same as those of Example 6, and will not be repeated here.

[0113] Comparative Example 6

[0114] The difference between this comparative example and Example 6 above is that the oil-locking layer in this comparative example includes the following components in the following weight ratio: diatomaceous earth 40.28: silica 53.72: pore-forming agent 22: glass powder 28: corundum 6: paraffin wax 25: oleic acid 3. The rest of the contents of this comparative example are the same as those of Example 6, and will not be repeated here.

[0115] Comparative Example 7

[0116] The difference between this comparative example and Example 6 above is that the oil-locking layer in this comparative example includes the following components in the following weight ratio: diatomaceous earth 38.57: silicon dioxide 51.43: pore-forming agent 22: glass powder 28: silicon carbide 10: paraffin wax 25: oleic acid 3. The rest of the contents of this comparative example are the same as those of Example 6, and will not be repeated here.

[0117] Comparative Example 8

[0118] The difference between this comparative example and Example 6 above is that:

[0119] The atomizing layer in this comparative example comprises the following components in the following weight ratio: diatomaceous earth 36: silica 48: pore-forming agent 22: glass powder 28: paraffin wax 25: oleic acid 3: silicon carbide 10: corundum 6; (these are the components and corresponding weight ratios of the oil-locking layer in Example 6)

[0120] The oil-locking layer in this comparative example comprises the following components in the following weight ratio: diatomaceous earth 48: silica 52: pore-forming agent 25: glass powder 25: paraffin wax 25: oleic acid 3; (the components and corresponding weight ratios of the atomizing layer in Example 6)

[0121] The oil-guiding layer in this comparative example comprises the following components in the following weight ratio: diatomaceous earth 58: silica 42: pore-forming agent 30: glass powder 20: paraffin wax 25: oleic acid 3; (the components and corresponding weight ratios of the oil-guiding layer in Example 6)

[0122] Based on the above adjustments to the components and proportions, the components and proportions of the atomizing layer and the oil-locking layer in Example 6 are interchanged, so that the porosity of the atomizing layer, the oil-locking layer, and the oil-guiding layer in this comparative example is set to a porosity of atomizing layer < porosity of oil-locking layer < porosity of oil-guiding layer.

[0123] The rest of the contents of this comparative example are the same as those of Example 6, and will not be repeated here.

[0124] Comparative Example 9

[0125] The difference between this comparative example and Example 6 above is that:

[0126] The atomizing layer in this comparative example comprises the following components in the following weight ratio: diatomaceous earth 58: silica 42: pore-forming agent 30: glass powder 20: paraffin wax 25: oleic acid 3; (the components and corresponding weight ratios of the oil-guiding layer in Example 6)

[0127] The oil-locking layer in this comparative example comprises the following components in the following weight ratios: diatomaceous earth 36: silica 48: pore-forming agent 22: glass powder 28: paraffin wax 25: oleic acid 3: silicon carbide 10: corundum 6; (These are the components and corresponding weight ratios of the oil-locking layer in Example 6)

[0128] The oil-guiding layer in this comparative example comprises the following components in the following weight ratio: diatomaceous earth 48: silica 52: pore-forming agent 25: glass powder 25: paraffin wax 25: oleic acid 3; (the components and corresponding weight ratios of the atomizing layer in Example 6)

[0129] Based on the above adjustments to the components and proportions, the components and proportions of the atomizing layer and the oil guiding layer in Example 6 are interchanged, so that the porosity of the atomizing layer, the oil locking layer, and the oil guiding layer in this comparative example is set to oil locking layer porosity < oil guiding layer porosity < atomizing layer porosity.

[0130] The rest of the contents of this comparative example are the same as those of Example 6, and will not be repeated here.

[0131] Comparative Example 10

[0132] The difference between this comparative example and Example 6 above is that:

[0133] The atomizing layer in this comparative example comprises the following components in the following weight ratio: diatomaceous earth 48: silica 52: pore-forming agent 25: glass powder 25: paraffin wax 25: oleic acid 3; (the components and corresponding weight ratios of the atomizing layer in Example 6)

[0134] The oil-locking layer in this comparative example comprises the following components in the following weight ratio: diatomaceous earth 58: silica 42: pore-forming agent 30: glass powder 20: paraffin wax 25: oleic acid 3; (the components and corresponding weight ratios of the oil-guiding layer in Example 6)

[0135] The oil-guiding layer in this comparative example comprises the following components in the following weight ratios: diatomaceous earth 36: silica 48: pore-forming agent 22: glass powder 28: paraffin wax 25: oleic acid 3: silicon carbide 10: corundum 6; (these are the components and corresponding weight ratios of the oil-locking layer in Example 6)

[0136] Based on the above adjustments to the components and proportions, the components and proportions of the oil guiding layer and the oil locking layer in Example 6 are interchanged, so that the porosity of the atomizing layer, the oil locking layer, and the oil guiding layer in this comparative example is set to oil guiding layer porosity < atomizing layer porosity < oil locking layer porosity.

[0137] The rest of the contents of this comparative example are the same as those of Example 6, and will not be repeated here.

[0138] The ceramic atomizing cores prepared in Examples 1-6 and Comparative Examples 1-10 were subjected to performance tests, and the test results are shown in Table 2 below:

[0139] Porosity: Porosity was tested according to Archimedes' drainage method, with liquid absorption time tested under the same conditions for a 10mm*4mm part;

[0140] Liquid absorption time: Place the ceramic atomizing core with the oil-conducting layer facing up on a mixture of 1.3-1.4g of propylene glycol and glycerol in a 1:1 volume ratio, and test the time it takes for the ceramic atomizing core to fully absorb the mixture.

[0141] Aperture testing: Aperture was tested using Auto Pore IV 9500 (Micromeritics Instrument Corporation);

[0142] Thermal conductivity test: Tested according to (GB / T 5990-2006);

[0143] Compressive strength test: On the compressive strength tester, place the ceramic atomizing core on the test fixture (with 2-3mm contact on both sides and the middle suspended) and test the compressive strength of the ceramic atomizing core;

[0144] Joint seam test: The cross-section of the ceramic atomizing core was examined using a crystal phase microscope.

[0145] Table 2

[0146]

[0147]

[0148] As can be seen from Examples 1-6 and Comparative Examples 1-10, the oil-guiding layer, oil-locking layer, and atomizing layer of the multilayer ceramic atomizing core are each composed of three components and ceramic materials with certain weight ratios, resulting in differences in porosity, pore size, and thermal conductivity of the atomizing layer ceramic matrix, the oil-locking layer ceramic matrix, and the oil-guiding layer ceramic matrix. According to Comparative Example 1... Figure 6 As shown, obvious delamination occurs at the joint of the oil guiding layer, oil locking layer, and atomizing layer. In Example 6, the oil guiding layer is disposed on the upper surface of the oil locking layer and wraps around the atomizing layer and the oil locking layer, as shown. Figure 5 As shown, the final multi-layered ceramic atomizing core layer is tightly bonded to each other, exhibiting good consistency. This avoids the drawbacks of gaps or delamination that existed in previous layer-to-layer bonding processes. While meeting the required oil absorption speed from the oil reservoir, it also prevents cracking at the joints caused by uneven shrinkage of the ceramic materials between layers. Furthermore, from... Figure 5 It is evident that the upper oil-guiding layer has the most pores, the middle oil-locking layer has the fewest pores, and the bottom atomizing layer has pores between the oil-guiding and oil-locking layers. The layers are tightly bonded together. Based on Comparative Examples 2-4 and 8-10, setting the porosity of the atomizing, oil-locking, and oil-guiding layers in the ceramic atomizing core to be: oil-locking layer porosity < atomizing layer porosity < oil-guiding layer porosity, ensures optimal liquid absorption time while also maintaining overall compressive strength and thermal conductivity. According to Comparative Examples 5-7, adding silicon carbide and corundum to the oil-locking layer effectively increases thermal conductivity and the overall compressive strength of the ceramic atomizing core while reducing porosity.

[0149] The specific embodiments described above are further illustrations of the technical solution and beneficial effects of the present invention, and are not intended to limit the implementation methods. For those skilled in the art, any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A multilayer ceramic atomizing core, characterized by: The system comprises an oil-guiding layer, an oil-locking layer, and an atomizing layer. A receiving groove is formed at the lower end of the oil-guiding layer. The oil-locking layer and the atomizing layer are sequentially disposed within the receiving groove from top to bottom. The porosity of the oil-guiding layer is greater than that of the atomizing layer, and the porosity of the atomizing layer is greater than that of the oil-locking layer. The raw materials for the oil-guiding layer, the oil-locking layer, and the atomizing layer respectively include at least one of diatomaceous earth, silica, a pore-forming agent, glass powder, paraffin wax, and oleic acid. The oil-locking layer further includes at least one of corundum and silicon carbide, and has the lowest porosity.

2. The multilayer ceramic atomizing core of claim 1, wherein: The atomizing layer is equipped with a heating wire.

3. The multilayer ceramic atomizing core of claim 1, wherein: The oil-guiding layer comprises the following components in the following weight ratio: diatomaceous earth 45-75: silica 25-55: pore-forming agent 10-35: glass powder 10-35: paraffin wax 20-40: oleic acid 2-5.

4. The multilayer ceramic atomizing core of claim 1, wherein: The oil-locking layer comprises the following components in the following weight ratio: diatomaceous earth 20-50: silicon dioxide 35-65: pore-forming agent 10-35: glass powder 10-35: corundum 1-10: silicon carbide 5-20: paraffin wax 20-40: oleic acid 2-5.

5. The multilayer ceramic atomizing core of claim 1, wherein: The atomizing layer comprises the following components in the following weight ratio: diatomaceous earth 35-65: silica 35-65: pore-forming agent 10-35: glass powder 10-35: paraffin wax 20-40: oleic acid 2-5.

6. The multilayer ceramic atomizing core of claim 1, wherein: The pore size of the oil guiding layer is larger than that of the atomizing layer, and the pore size of the atomizing layer is larger than that of the oil locking layer.

7. The multilayer ceramic atomizing core according to any one of claims 3, 4, or 5, characterized in that: The pore-forming agent is at least one of polyethylene, methylcellulose, graphite powder, starch, walnut powder, carbon powder, and PMMA.

8. The multilayer ceramic atomizing core according to any one of claims 3, 4, or 5, characterized in that: The glass powder is a low-temperature glass powder.

9. A method for preparing a multilayer ceramic atomizing core according to any one of claims 1-6, characterized in that... Includes the following steps: (1) According to the weight parts, diatomaceous earth, silica, pore-forming agent, glass powder and oleic acid are ball-milled and mixed evenly to obtain atomized layer ceramic material. The ball-milled ceramic material is dried at a temperature of 80-125℃. At the same time, paraffin is heated to 90-125℃ to melt it. Then, the dried atomized layer ceramic material is added while stirring. After the addition is completed, stirring is continued for 2-4 hours to obtain atomized layer ceramic slurry for later use. (2) According to the weight parts, diatomaceous earth, silica, pore-forming agent, glass powder, oleic acid, corundum and silicon carbide are ball-milled and mixed evenly to obtain oil-locking layer ceramic material. The ball-milled ceramic material is dried at a temperature of 80-125℃. At the same time, paraffin is heated to 90-125℃ to melt it. Then, the dried oil-locking layer ceramic material is added while stirring. After the addition is completed, stirring is continued for 2-4 hours to obtain oil-locking layer ceramic slurry for later use. (3) According to the weight parts, diatomaceous earth, silica, pore-forming agent, glass powder and oleic acid are ball-milled and mixed evenly to obtain oil-conducting layer ceramic material. The ball-milled ceramic material is dried at a temperature of 80-125℃. At the same time, the paraffin is heated to 90-125℃ to melt it. Then the dried oil-conducting layer ceramic material is added while stirring. After the addition is completed, stirring is continued for 2-4 hours to obtain oil-conducting layer ceramic slurry for later use. (4) First molding: The heating wire is placed in the hot press mold, and then the atomized layer ceramic slurry is injected into the hot press mold for hot press molding. Under the conditions of temperature of 70-90℃ and pressure of 4-5MPa, the atomized layer ceramic matrix is ​​obtained for later use. (5) Second molding: The atomized layer ceramic substrate obtained in step (4) is placed in a hot press mold, and the oil-locking layer ceramic slurry is injected for a second hot press molding. Under the conditions of temperature of 70-100℃ and pressure of 4-7MPa, the atomized layer and oil-locking layer combined ceramic substrate is obtained for later use. (6) Third molding: Place the ceramic matrix of the atomizing layer and the oil-locking layer obtained in step (5) into a hot press mold, inject the oil-guiding layer ceramic slurry for the third hot press molding, and make a multi-layer ceramic atomizing core matrix under the conditions of temperature of 70-100℃ and pressure of 4-7MPa for later use. (7) Debinding: Place the multilayer ceramic atomizing core substrate obtained in step (6) into a debinding furnace, use air as the debinding atmosphere, and debind at 400-800℃ for 2-6 hours. (8) Sintering: The multilayer ceramic atomizing core substrate obtained in step (7) is transferred to a sintering furnace, air is used as the sintering atmosphere, and sintering is carried out according to the sintering curve to produce a multilayer ceramic atomizing core.

10. The method for preparing the multilayer ceramic atomizing core according to claim 9, characterized in that: In step (8), the sintering curve includes the following steps: S1. Heating stage: Increase the temperature from room temperature to 400-500℃ at a rate of 3-8℃ / minute, and keep it at 400-500℃ for 2-3 hours. S2, Intermediate heat preservation stage: Heat to 600-700℃ and keep warm for 2-4 hours; S3, High-temperature sintering stage: Continue to raise the temperature to 800-1000℃ and hold for 4-6 hours; S4. Cooling stage: After sintering, the material is naturally cooled to room temperature to obtain a multi-layer ceramic atomizing core.

Images