Manufacturing method of carbon fiber rigid felt cylinder

Abstract

This application relates to a method for manufacturing a carbon fiber rigid felt cylinder, comprising the following steps: S10 immersing a first section of carbon fiber preform in a first immersion solution, and immersing a second section of carbon fiber preform in a second immersion solution, wherein the first and second immersion solutions have different compositions; S20 processing the first section of carbon fiber preform into an inner cylinder, and processing the second section of carbon fiber preform into an outer cylinder that mates with the inner cylinder, wherein the inner and outer cylinders are combined to form a rigid felt cylinder preform; S30 subjecting the rigid felt cylinder preform to heat treatment to form a finished rigid felt cylinder. The technical solution of this application effectively solves the problem in the prior art that the thermal insulation performance and oxidation resistance of carbon fiber rigid felt cylinders cannot be simultaneously achieved.

Description

Technical Field

[0001] This application relates to the technical field of carbon fiber rigid felt cylinder manufacturing, and more specifically, to a method for manufacturing a carbon fiber rigid felt cylinder. Background Technology

[0002] Carbon fiber is mainly composed of carbon elements and has properties such as high temperature resistance, friction resistance and corrosion resistance. It is fibrous in shape, soft and can be processed into various fabrics. Due to its graphite microcrystalline structure preferentially oriented along the fiber axis, it has high strength and modulus along the fiber axis.

[0003] Carbon fiber rigid felt cylinders can be used for insulation, such as as an insulation layer in the hot zone of a single crystal furnace. Existing conventional rigid felt cylinders reduce their overall density to improve insulation performance. However, while this improves insulation, it increases the number of voids in the felt cylinder, reduces its oxidation resistance, and consequently shortens the overall lifespan of the rigid felt cylinder.

[0004] When rigid felt tubes are used in single crystal furnaces, if there is any oxidation on the inner wall, powder will form at the oxidized area, which will then contaminate the furnace cavity and reduce the heat insulation effect of the carbon fiber rigid felt tubes. Summary of the Invention

[0005] This application provides a method for manufacturing a carbon fiber rigid felt cylinder to solve the problem that the thermal insulation performance and oxidation resistance performance of the carbon fiber rigid felt cylinder in the prior art cannot be simultaneously achieved.

[0006] According to the present application, a method for manufacturing a carbon fiber rigid felt cylinder includes the following steps: S10, immersing a first section of carbon fiber preform in a first immersion solution and immersing a second section of carbon fiber preform in a second immersion solution, wherein the first and second immersion solutions have different compositions; S20, processing the first section of carbon fiber preform into an inner cylinder and processing the second section of carbon fiber preform into an outer cylinder that matches the inner cylinder, wherein the inner cylinder and the outer cylinder are combined to form a rigid felt cylinder preform; S30, subjecting the rigid felt cylinder preform to heat treatment to form a finished rigid felt cylinder.

[0007] Furthermore, the first soaking solution comprises: boron carbide powder, water-soluble phenolic resin, octanol polyoxyethylene ether, multi-walled carbon nanotube powder, and pure water;

[0008] Preferably, by mass percentage: 10-18% boron carbide powder with a particle size of 1-10 micrometers, 20-35% water-soluble phenolic resin, 1-4% octanol polyoxyethylene ether, 6-13% multi-walled carbon nanotube powder with a particle size of 10-30 nanometers, and 30-50% pure water.

[0009] Furthermore, the first soaking solution comprises: silicon nitride, phenolic resin, octylbenzene polyoxyethylene ether, single-walled carbon nanotube powder, and pure water;

[0010] Preferably, by mass percentage: 10-25% silicon nitride powder with a particle size of 1-10 micrometers, 25-35% water-soluble phenolic resin, 1-4% octylbenzene polyoxyethylene ether, 5-10% single-walled carbon nanotube powder with a particle size of 10-30 nanometers, and 30-50% pure water.

[0011] Furthermore, the first soaking solution comprises: triammonium phosphate, water-soluble phenolic resin, octanol polyoxyethylene ether, single-walled carbon nanotube powder, and pure water;

[0012] Preferably, by mass percentage: 10-25% triammonium phosphate powder with a particle size of 1-10 micrometers, 20-35% water-soluble phenolic resin, 1-4% octanol polyoxyethylene ether, 10-20% single-walled carbon nanotube powder with a particle size of 10-30 nanometers, and 30-50% pure water.

[0013] Furthermore, the second soaking solution comprises: phenolic resin and pure water;

[0014] Preferably, the mixture contains 20-40% water-soluble phenolic resin and 50-80% pure water.

[0015] Furthermore, before step S10, the process includes making a total preform using carbon fiber short filaments and cutting the total preform into a first carbon fiber preform and a second carbon fiber preform, wherein the ratio of the length of the first carbon fiber preform to the length of the second carbon fiber preform is between 3:7 and 3:2.

[0016] Furthermore, the cutting surface of the precast body is an inclined surface, and the connection points of the inner cylinder and the outer cylinder are staggered.

[0017] Furthermore, the heat treatment includes a curing stage and a graphitization stage.

[0018] Furthermore, the curing stage includes: a moisture evaporation stage and a resin curing stage;

[0019] Preferably, the steps of the moisture evaporation stage include: baking in an oven, with the temperature controlled at 50-100℃ and the time controlled at 1-5 hours.

[0020] Preferably, the resin curing stage includes the following steps: heating to 120-190°C, baking for 1-4 hours while the mold is continuously rotated.

[0021] Furthermore, the graphitization process includes: sending the cured preform into a high-temperature furnace for graphitization.

[0022] Preferably, the cured hard felt cylinder preform is placed in a high-temperature furnace at 2200°C to 2800°C for graphitization treatment.

[0023] By applying the technical solution of this application, the first and second carbon fiber preforms are immersed in different soaking solutions and then heat-treated, resulting in differences in their properties. This achieves both thermal insulation and oxidation resistance, thus balancing both aspects. The technical solution of this application effectively solves the problem in existing technologies where carbon fiber rigid felt cylinders cannot simultaneously achieve both thermal insulation and oxidation resistance. Attached Figure Description

[0024] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A flowchart illustrating the manufacturing method of the carbon fiber rigid felt cylinder according to an embodiment of this application is shown;

[0027] Figure 2 It shows Figure 1 A schematic diagram of the structure of a carbon fiber rigid felt cylinder, illustrating the manufacturing method of the carbon fiber rigid felt cylinder.

[0028] Figure 3 It shows Figure 2 A schematic diagram of the connection structure of the carbon fiber rigid felt tube.

[0029] The above figures include the following reference numerals:

[0030] 10. Inner cylinder; 20. Outer cylinder. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0033] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, rotated 90 degrees, or in other orientations, and the spatial relative descriptions used herein will be interpreted accordingly.

[0034] like Figures 1 to 3 As shown, a method for manufacturing a carbon fiber rigid felt cylinder according to this application includes the following steps: S10, immersing a first section of carbon fiber preform in a first immersion solution, and immersing a second section of carbon fiber preform in a second immersion solution, wherein the first and second immersion solutions have different compositions. S20, processing the first section of carbon fiber preform into an inner cylinder, and processing the second section of carbon fiber preform into an outer cylinder that mates with the inner cylinder, wherein the inner and outer cylinders are combined to form a rigid felt cylinder preform. S30, subjecting the rigid felt cylinder preform to heat treatment to form a finished rigid felt cylinder.

[0035] By applying the technical solution of this application, the first and second carbon fiber preforms are immersed in different soaking solutions and then heat-treated, resulting in differences in their properties. This achieves both thermal insulation and oxidation resistance, thus balancing both aspects. The technical solution of this application effectively solves the problem in existing technologies where carbon fiber rigid felt cylinders cannot simultaneously achieve both thermal insulation and oxidation resistance.

[0036] It should be noted that the first section of the carbon fiber preform is processed into the inner cylinder 10, and the second section of the carbon fiber preform is processed into the outer cylinder 20.

[0037] In this application, the first soaking solution comprises: boron carbide powder, water-soluble phenolic resin, octanol polyoxyethylene ether, multi-walled carbon nanotube powder, and pure water. Preferably, by mass percentage: 10-18% boron carbide powder with a particle size of 1-10 micrometers, 20-35% water-soluble phenolic resin, 1-4% octanol polyoxyethylene ether, 6-13% multi-walled carbon nanotube powder with a particle size of 10-30 nanometers, and 30-50% pure water. The residual carbon content of the phenolic resin in this application is between 30-35%. Boron carbide is the main factor increasing antioxidant properties, octanol polyoxyethylene ether can enhance the stability of the solution, allowing the soft felt to be soaked more thoroughly, and carbon nanotubes are added because boron carbide can make the felt container brittle at high temperatures, and adding a certain amount of carbon nanotubes can enhance the strength of the felt container at high temperatures.

[0038] The formulation of the first soaking solution in this application may also include: silicon nitride, phenolic resin, octylphenyl polyoxyethylene ether, single-walled carbon nanotube powder, and pure water. Preferably, by mass percentage: 10-25% silicon nitride powder with a particle size of 1-10 micrometers, 25-35% water-soluble phenolic resin, 1-4% octylphenyl polyoxyethylene ether, 5-10% single-walled carbon nanotube powder with a particle size of 10-30 nanometers, and 30-50% pure water. Silicon nitride serves as the main raw material for anti-oxidation, while carbon nanotubes can enhance antioxidant properties and ensure a certain level of strength.

[0039] The first soaking solution of this application may further comprise: triammonium phosphate, water-soluble phenolic resin, octanol polyoxyethylene ether, single-walled carbon nanotube powder, and pure water. Preferably, by mass percentage: 10-25% triammonium phosphate powder with a particle size of 1-10 micrometers, 20-35% water-soluble phenolic resin, 1-4% octanol polyoxyethylene ether, 10-20% single-walled carbon nanotube powder with a particle size of 10-30 nanometers, and 30-50% pure water. Triammonium phosphate serves as the main raw material for antioxidation, while carbon nanotubes provide strong antioxidant properties and ensure a certain level of strength.

[0040] The second soaking solution of this application comprises phenolic resin and pure water. Preferably, the mass percentage is 20-40% water-soluble phenolic resin and 50-80% pure water.

[0041] In the technical solution of this application, before step S10, a total preform is made by using short carbon fiber filaments, and the total preform is cut into a first carbon fiber preform and a second carbon fiber preform. The ratio of the length of the first carbon fiber preform to the length of the second carbon fiber preform is between 3:7 and 3:2. Experimental analysis shows that the above ratio provides good comprehensive performance in terms of thermal insulation and oxidation resistance. By measuring the above ratio, the carbon fiber rigid felt cylinder can be directly cut during manufacturing without calculating the wall thickness of the inner cylinder 10 and the outer cylinder 20, as well as other indicators such as thermal insulation and oxidation resistance, which greatly improves manufacturing efficiency.

[0042] In the technical solution of this application, the cutting surface of the precast body is an inclined surface, and the connection points of the inner cylinder and the outer cylinder are staggered. The inclined surface makes the mating area of ​​the connection larger, the connection effect better, and there is no change in gap. The staggered arrangement of the connection points of the inner cylinder 10 and the outer cylinder 20 results in better thermal insulation performance and oxidation resistance, and a longer service life.

[0043] In the technical solution of this application, the heat treatment includes a curing stage and a graphitization stage.

[0044] In the technical solution of this application, the curing stage includes a moisture evaporation stage and a resin curing stage. Preferably, the moisture evaporation stage includes baking in an oven at a temperature controlled at 50-100°C for 1-5 hours. This facilitates the removal of moisture first. Preferably, the resin curing stage includes heating to 120-190°C and baking for 1-4 hours while the mold is continuously rotated.

[0045] In the technical solution of this application, the graphitization stage includes: sending the cured pre-product into a high-temperature furnace for graphitization. Preferably, the cured hard felt cylinder pre-product is placed in a high-temperature furnace at 2200℃ to 2800℃ for graphitization. Such a hard felt cylinder has better performance.

[0046] In summary, the detailed steps of the technical solution of this application are as follows: the carbon fiber filament is cut into short filaments of 50-70mm, and after being combed in a carding machine, it is made into a mesh. The mesh is then needle-punched and composited using a continuous needle-punching device to form a preform (the total preform mentioned above) with a length between 1 meter and 20 meters, a width between 0.5 meters and 1.5 meters, and a thickness between 7mm and 14mm. The length, thickness, and width can be specified according to specific usage requirements.

[0047] Cut the precast structure into two sections according to the required total length (other methods are also possible, such as cutting it into multiple sections if the total length is too long). The first section should be 30-60% of the total length, and the second section 40-70% of the total length. Cut the joint between the two carbon fiber precast sections at an angle to achieve the best connection effect, ensuring a tight connection without gaps. The final shape is shown in the attached figure. Figure 3 As shown. The thickness ratio of the inner cylinder 10 to the outer cylinder 20 is between 0.8 and 1.2.

[0048] The two sections of cut soft felt (carbon fiber preform) were immersed in two different types of resin solutions to obtain the special properties of each section.

[0049] The first soaking solution for the first section of the carbon fiber preform consists of one of three components:

[0050] ① 10-18% boron carbide powder with a particle size of 1-10 micrometers, 20-35% water-soluble phenolic resin (with residual carbon content between 30-35%), 1-4% octanol polyoxyethylene ether, 6-13% multi-walled carbon nanotube powder with a particle size of 10-30 nanometers, and 30-50% pure water.

[0051] ②10-25% silicon nitride powder with a particle size of 1-10 micrometers, 25-35% water-soluble phenolic resin (with residual carbon content between 30-35%), 1-4% octylbenzene polyoxyethylene ether, 5-10% single-walled carbon nanotube powder with a particle size of 10-30 nanometers, and 30-50% pure water.

[0052] ③ 10-25% triammonium phosphate powder with a particle size of 1-10 micrometers, 20-35% water-soluble phenolic resin (with residual carbon content between 30-35%), 1-4% octanol polyoxyethylene ether, 10-20% single-walled carbon nanotube powder with a particle size of 10-30 nanometers, and 30-50% pure water.

[0053] The second soaking solution for the second section of the carbon fiber preform consists of 20-40% water-soluble phenolic resin and 50-80% pure water (this is a commonly used component in the production of ordinary rigid felt cylinders).

[0054] The first and second carbon fiber preforms, after soaking, are sequentially wrapped onto the wooden mold and baked in an oven at 50-100℃ for 1-5 hours. The temperature is then increased to 120-190℃ for 1-4 hours. The first stage temperature is conducive to the evaporation of water from the solution and prevents the resin from curing, thus reducing stress concentration. The second stage temperature is the resin curing temperature. During production, the wooden mold is continuously rotated by a motor to prevent uneven distribution of the resin due to the increased viscosity and fluidity caused by the increased temperature during baking.

[0055] The cured hard felt cylinder is then placed in a 2500℃ high-temperature furnace for graphitization treatment.

[0056] The final product, a carbon fiber rigid felt cylinder, is obtained.

[0057] The following analysis uses several specific embodiments:

[0058] Example 1:

[0059] The carbon fiber precursor is cut into 55mm short filaments, which are then carded in a carding machine to form a mesh. The mesh is then needle-punched and composited using a continuous needle-punching device to form a preform with a length of 10 meters, a width of 1 meter, and a thickness of 12mm. In actual manufacturing, the length, thickness, and width can be specified according to specific usage requirements, so that the products produced are not limited.

[0060] The precast structure is cut into two sections according to the required total length. The first section is 40% of the total length, and the second section is 60% of the total length. The joint between the two sections is cut at an angle to achieve the best connection effect, ensuring a tight fit without gaps. This prevents the insulation cylinder from detaching at high temperatures. The final shape is shown in the attached figure. Figure 3 As shown.

[0061] The two sections of cut soft felt (carbon fiber preform) were immersed in two different types of resin solutions to obtain the special properties of each section.

[0062] The first soaking solution for the first section of the carbon fiber preform consists of:

[0063] 18% boron carbide powder with a particle size of 10 micrometers, 25% water-soluble phenolic resin (with a residual carbon content of 32%), 3% octanol polyoxyethylene ether, 10% multi-walled carbon nanotube powder with a particle size of 30 nanometers, and 44% pure water.

[0064] The second soaking solution for the second section of the carbon fiber preform consists of 30% water-soluble phenolic resin and 70% pure water (this is a commonly used component in the production of ordinary rigid felt cylinders).

[0065] The first and second carbon fiber preforms, after soaking, are sequentially wrapped onto a wooden mold and baked in an oven at 70°C for 2 hours, then the temperature is increased to 150°C for 1.5 hours. The temperature in the first stage is conducive to the evaporation of water from the solution and prevents the resin from curing, thus reducing stress concentration. The second stage temperature is the resin curing temperature.

[0066] The cured hard felt cylinder is then placed in a 2500℃ high-temperature furnace for graphitization treatment.

[0067] The final product is obtained.

[0068] Example 2:

[0069] The carbon fiber precursor is cut into 55mm short filaments, which are then carded in a carding machine to form a mesh. The mesh is then needle-punched and composited using a continuous needle-punching device to form a preform with a length of 10 meters, a width of 1 meter, and a thickness of 12mm. In actual manufacturing, the length, thickness, and width can be specified according to specific usage requirements, so that the products produced are not limited.

[0070] The precast structure is cut into two sections according to the required total length. The first section is 40% of the total length, and the second section is 60% of the total length. The joint between the two sections is cut at an angle to achieve the best connection effect, ensuring a tight fit without gaps. This prevents the insulation cylinder from detaching at high temperatures. The final shape is shown in the attached figure. Figure 3 As shown.

[0071] The two sections of cut soft felt were soaked in two different types of resin solutions to obtain the special properties of each section.

[0072] 4. Components of the soaking solution in the first section:

[0073] 10% boron carbide powder with a particle size of 10 micrometers, 25% water-soluble phenolic resin (32% residual carbon), 3% octanol polyoxyethylene ether, 13% multi-walled carbon nanotube powder with a particle size of 30 nanometers, and 49% pure water.

[0074] 5. The soaking solution in the second section consists of 30% water-soluble phenolic resin and 70% pure water (this is a commonly used component in the production of ordinary hard felt tubes).

[0075] 6. After soaking, wrap the first and second sections of soft felt onto the wooden mold in sequence, and bake in an oven at 70°C for 2 hours, then raise the temperature to 150°C for 1.5 hours. The temperature of the first stage is conducive to the evaporation of water in the solution and prevents the resin from curing, thus reducing stress concentration. The temperature of the second stage is the resin curing temperature.

[0076] 7. The cured hard felt cylinder is placed in a 2500℃ high-temperature furnace for graphitization treatment.

[0077] 8. Obtain the final product

[0078] Example 3 (Best):

[0079] The carbon fiber precursor is cut into 55mm short filaments, which are then carded in a carding machine to form a mesh. The mesh is then needle-punched and composited using a continuous needle-punching device to form a preform with a length of 10 meters, a width of 1 meter, and a thickness of 12mm. In actual manufacturing, the length, thickness, and width can be specified according to specific usage requirements, so that the products produced are not limited.

[0080] The precast structure is cut into two sections according to the required total length. The first section is 40% of the total length, and the second section is 60%. The joint between the two sections (the first and second sections) is cut at an angle to achieve the best connection, ensuring a tight fit without gaps. This prevents the insulation cylinder from detaching at high temperatures. The final shape is shown in the attached figure. Figure 3 As shown.

[0081] The two sections of cut soft felt were soaked in two different types of resin solutions to obtain the special properties of each section.

[0082] 4. Components of the first immersion solution for the first section of carbon fiber preform:

[0083] 14% boron carbide powder with a particle size of 10 micrometers, 30% water-soluble phenolic resin (with a residual carbon content of 32%), 4% octanol polyoxyethylene ether, 11% multi-walled carbon nanotube powder with a particle size of 30 nanometers, and 41% pure water.

[0084] 5. The second soaking solution for the second section of the carbon fiber preform consists of: 30% water-soluble phenolic resin and 70% pure water (this is a commonly used component in the production of ordinary rigid felt cylinders).

[0085] 6. After soaking, the first section of soft felt (the first section of carbon fiber preform) and the second section of soft felt (the second section of carbon fiber preform) are sequentially wrapped on the wooden mold and placed in an oven for baking. The temperature stage is 70℃ for 2 hours, and then the temperature is increased to 150℃ for 1.5 hours. The temperature of the first stage is conducive to the evaporation of water in the solution and the resin will not solidify, thus reducing stress concentration. The temperature of the second stage is the resin curing temperature.

[0086] 7. The cured hard felt cylinder is placed in a 2500℃ high-temperature furnace for graphitization treatment.

[0087] 8. Obtain the final product.

[0088] Example 4 (changing the soaking solution):

[0089] The carbon fiber precursor is cut into 55mm short filaments, which are then carded in a carding machine to form a mesh. The mesh is then needle-punched and composited using a continuous needle-punching device to form a preform with a length of 10 meters, a width of 1 meter, and a thickness of 12mm. In actual manufacturing, the length, thickness, and width can be specified according to specific usage requirements, so that the products produced are not limited.

[0090] The precast structure is cut into two sections according to the required total length. The first section is 40% of the total length, and the second section is 60% of the total length. The joint between the two sections is cut at an angle to achieve the best connection effect, ensuring a tight fit without gaps. This prevents the insulation cylinder from detaching at high temperatures. The final shape is shown in the attached figure. Figure 3 As shown.

[0091] The two sections of cut soft felt were soaked in two different types of resin solutions to obtain the special properties of each section.

[0092] 4. Components of the soaking solution in the first section:

[0093] 14% silicon nitride powder with a particle size of 5 micrometers, 25% water-soluble phenolic resin (32% residual carbon), 4% octylbenzene polyoxyethylene ether, 7% single-walled carbon nanotube powder with a particle size of 20 nanometers, and 50% pure water.

[0094] 5. The soaking solution in the second section consists of 30% water-soluble phenolic resin and 70% pure water (this is a commonly used component in the production of ordinary hard felt tubes).

[0095] 6. After soaking, wrap the first and second sections of soft felt onto the wooden mold in sequence, and bake them in an oven at 70℃ for 2 hours, then raise the temperature to 150℃ for 1.5 hours. The temperature in the first stage is conducive to the evaporation of water from the solution and prevents the resin from curing, thus reducing stress concentration. The temperature in the second stage is the resin curing temperature.

[0096] 7. The cured hard felt cylinder is placed in a 2500℃ high-temperature furnace for graphitization treatment.

[0097] 8. Obtain the final product.

[0098] Example 5 (changing the soaking solution):

[0099] The carbon fiber precursor is cut into 55mm short filaments, which are then carded in a carding machine to form a mesh. The mesh is then needle-punched and composited using a continuous needle-punching device to form a preform with a length of 10 meters, a width of 1 meter, and a thickness of 12mm. In actual manufacturing, the length, thickness, and width can be specified according to specific usage requirements, so that the products produced are not limited.

[0100] The precast structure is cut into two sections according to the required total length. The first section is 40% of the total length, and the second section is 60% of the total length. The joint between the two sections is cut at an angle to achieve the best connection effect, ensuring a tight fit without gaps. This prevents the insulation cylinder from detaching at high temperatures. The final shape is shown in the attached figure. Figure 3 As shown.

[0101] The two sections of cut soft felt were soaked in two different types of resin solutions to obtain the special properties of each section.

[0102] 4. Components of the soaking solution in the first section:

[0103] 25% silicon nitride powder with a particle size of 5 micrometers, 25% water-soluble phenolic resin (with a residual carbon content of 32%), 4% octylbenzene polyoxyethylene ether, 10% single-walled carbon nanotube powder with a particle size of 20 nanometers, and 36% pure water.

[0104] 5. The soaking solution in the second section consists of 30% water-soluble phenolic resin and 70% pure water (this is a commonly used component in the production of ordinary hard felt tubes).

[0105] 6. After soaking, wrap the first and second sections of soft felt onto the wooden mold in sequence, and bake them in an oven at 70℃ for 2 hours, then raise the temperature to 150℃ for 1.5 hours. The temperature in the first stage is conducive to the evaporation of water from the solution and prevents the resin from curing, thus reducing stress concentration. The temperature in the second stage is the resin curing temperature.

[0106] 7. The cured hard felt cylinder is placed in a 2500℃ high-temperature furnace for graphitization treatment.

[0107] 8. Obtain the final product

[0108] Example 6 (Replacing the soaking solution):

[0109] The carbon fiber precursor is cut into 55mm short filaments, which are then carded in a carding machine to form a mesh. The mesh is then needle-punched and composited using a continuous needle-punching device to form a preform with a length of 10 meters, a width of 1 meter, and a thickness of 12mm. In actual manufacturing, the length, thickness, and width can be specified according to specific usage requirements, so that the products produced are not limited.

[0110] The precast structure is cut into two sections according to the required total length. The first section is 40% of the total length, and the second section is 60% of the total length. The joint between the two sections is cut at an angle to achieve the best connection effect, ensuring a tight fit without gaps. This prevents the insulation cylinder from detaching at high temperatures. The final shape is shown in the attached figure. Figure 3 As shown.

[0111] The two sections of cut soft felt were soaked in two different types of resin solutions to obtain the special properties of each section.

[0112] 4. Components of the soaking solution in the first section:

[0113] ③ 25% triammonium phosphate powder with a particle size of 1-10 micrometers, 35% water-soluble phenolic resin (with a residual carbon content of 32%), 4% octanol polyoxyethylene ether, 20% single-walled carbon nanotube powder with a particle size of 10 nanometers, and 16% pure water.

[0114] 5. The soaking solution in the second section consists of 30% water-soluble phenolic resin and 70% pure water (this is a commonly used component in the production of ordinary hard felt tubes).

[0115] 6. After soaking, wrap the first and second sections of soft felt onto the wooden mold in sequence, and bake in an oven at 70℃ for 2 hours, then raise the temperature to 150℃ for 1.5 hours. The temperature of the first stage is conducive to the evaporation of water in the solution and prevents the resin from curing, thus reducing stress concentration. The temperature of the second stage is the resin curing temperature.

[0116] 7. The cured hard felt cylinder is placed in a 2500℃ high-temperature furnace for graphitization treatment.

[0117] 8. Obtain the final product.

[0118] Example 7 (Replacing the soaking solution):

[0119] The carbon fiber precursor is cut into 55mm short filaments, which are then carded in a carding machine to form a mesh. The mesh is then needle-punched and composited using a continuous needle-punching device to form a preform with a length of 10 meters, a width of 1 meter, and a thickness of 12mm. In actual manufacturing, the length, thickness, and width can be specified according to specific usage requirements, so that the products produced are not limited.

[0120] The precast structure is cut into two sections according to the required total length. The first section is 40% of the total length, and the second section is 60% of the total length. The joint between the two sections is cut at an angle to achieve the best connection effect, ensuring a tight fit without gaps. This prevents the insulation cylinder from detaching at high temperatures. The final shape is shown in the attached figure. Figure 3 As shown.

[0121] The two sections of cut soft felt were soaked in two different types of resin solutions to obtain the special properties of each section.

[0122] 4. Components of the soaking solution in the first section:

[0123] ③ 10% triammonium phosphate powder with a particle size of 1-10 micrometers, 35% water-soluble phenolic resin (32% residual carbon), 4% octanol polyoxyethylene ether, 15% single-walled carbon nanotube powder with a particle size of 10 nanometers, and 36% pure water.

[0124] 5. The soaking solution in the second section consists of 30% water-soluble phenolic resin and 70% pure water (this is a commonly used component in the production of ordinary hard felt tubes).

[0125] 6. After soaking, wrap the first and second sections of soft felt onto the wooden mold in sequence, and bake them in an oven at 70℃ for 2 hours, then raise the temperature to 150℃ for 1.5 hours. The temperature in the first stage is conducive to the evaporation of water from the solution and prevents the resin from curing, thus reducing stress concentration. The temperature in the second stage is the resin curing temperature.

[0126] 7. The cured hard felt cylinder is placed in a 2500℃ high-temperature furnace for graphitization treatment.

[0127] 8. Obtain the final product.

[0128] Example 8 (Changing the lengths of the two segments) The first segment becomes longer:

[0129] The carbon fiber precursor is cut into 55mm short filaments, which are then carded in a carding machine to form a mesh. The mesh is then needle-punched and composited using a continuous needle-punching device to form a preform with a length of 10 meters, a width of 1 meter, and a thickness of 12mm. In actual manufacturing, the length, thickness, and width can be specified according to specific usage requirements, so that the products produced are not limited.

[0130] The precast structure is cut into two sections according to the required total length. The first section is 60% of the total length, and the second section is 40% of the total length. The joint between the two sections is cut at an angle to achieve the best connection effect, ensuring a tight fit without gaps. This prevents the insulation cylinder from detaching at high temperatures. The final shape is shown in the attached figure. Figure 3 As shown.

[0131] The two sections of cut soft felt were soaked in two different types of resin solutions to obtain the special properties of each section.

[0132] 4. Components of the soaking solution in the first section:

[0133] ① 14% boron carbide powder with a particle size of 10 micrometers, 30% water-soluble phenolic resin (with a residual carbon content of 32%), 4% octanol polyoxyethylene ether, 11% multi-walled carbon nanotube powder with a particle size of 30 nanometers, and 41% pure water.

[0134] 5. The soaking solution in the second section consists of 30% water-soluble phenolic resin and 70% pure water (this is a commonly used component in the production of ordinary hard felt tubes).

[0135] 6. After soaking, wrap the first and second sections of soft felt onto the wooden mold in sequence, and bake in an oven at 70℃ for 2 hours, then raise the temperature to 150℃ for 1.5 hours. The temperature of the first stage is conducive to the evaporation of water in the solution and prevents the resin from curing, thus reducing stress concentration. The temperature of the second stage is the resin curing temperature.

[0136] 7. The cured hard felt cylinder is placed in a 2500℃ high-temperature furnace for graphitization treatment.

[0137] 8. Obtain the final product.

[0138] Example 9 (Changing the lengths of the two segments) The first segment becomes shorter:

[0139] The carbon fiber precursor is cut into 55mm short filaments, which are then carded in a carding machine to form a mesh. The mesh is then needle-punched and composited using a continuous needle-punching device to form a preform with a length of 10 meters, a width of 1 meter, and a thickness of 12mm. In actual manufacturing, the length, thickness, and width can be specified according to specific usage requirements, so that the products produced are not limited.

[0140] The precast structure is cut into two sections according to the required total length. The first section is 30% of the total length, and the second section is 70% of the total length. The joint between the two sections is cut at an angle to achieve the best connection effect, ensuring a tight fit without gaps. This prevents the insulation cylinder from detaching at high temperatures. The final shape is shown in the attached figure. Figure 3 As shown.

[0141] The two sections of cut soft felt were soaked in two different types of resin solutions to obtain the special properties of each section.

[0142] 4. Components of the soaking solution in the first section:

[0143] ① 14% boron carbide powder with a particle size of 10 micrometers, 30% water-soluble phenolic resin (with a residual carbon content of 32%), 4% octanol polyoxyethylene ether, 11% multi-walled carbon nanotube powder with a particle size of 30 nanometers, and 41% pure water.

[0144] 5. The soaking solution in the second section consists of 30% water-soluble phenolic resin and 70% pure water (this is a commonly used component in the production of ordinary hard felt tubes).

[0145] 6. After soaking, wrap the first and second sections of soft felt onto the wooden mold in sequence, and bake in an oven at 70℃ for 2 hours, then raise the temperature to 150℃ for 1.5 hours. The temperature of the first stage is conducive to the evaporation of water in the solution and prevents the resin from curing, thus reducing stress concentration. The temperature of the second stage is the resin curing temperature.

[0146] 7. The cured hard felt cylinder is placed in a 2500℃ high-temperature furnace for graphitization treatment.

[0147] 8. Obtain the final product

[0148] Comparative Example 1:

[0149] Thermal insulation felt cylinders manufactured using the methods described in sections 0071 to 0082 of CN106747552A.

[0150] The results of testing the samples prepared in each embodiment are shown in Table 1.

[0151] Table 1

[0152]

[0153]

[0154] Based on the table above, Example 3 shows the best thermal conductivity at the lowest weight loss, meaning that the formulation of Example 3 is optimal.

[0155] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0156] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0157] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for manufacturing a carbon fiber rigid felt cylinder, characterized in that, Includes the following steps: S10 The first section of carbon fiber preform is immersed in the first immersion solution, and the second section of carbon fiber preform is immersed in the second immersion solution. The first immersion solution and the second immersion solution have different compositions. S20 The first section of carbon fiber preform is processed into an inner cylinder, and the second section of carbon fiber preform is processed into an outer cylinder that matches the inner cylinder. The inner cylinder and the outer cylinder are combined to form a rigid felt cylinder preform. S30 The preformed rigid felt cylinder is heated to form a finished rigid felt cylinder; The first soaking solution comprises: boron carbide powder, water-soluble phenolic resin, octanol polyoxyethylene ether, multi-walled carbon nanotube powder, and pure water; By mass percentage: 10-18% boron carbide powder with a particle size of 1-10 micrometers, 20-35% water-soluble phenolic resin, 1-4% octanol polyoxyethylene ether, 6-13% multi-walled carbon nanotube powder with a particle size of 10-30 nanometers, and 30-50% pure water. The second soaking solution comprises: phenolic resin and pure water; 20-40% water-soluble phenolic resin, 50-80% pure water; or The first soaking solution was replaced with: silicon nitride, phenolic resin, octylbenzene polyoxyethylene ether, single-walled carbon nanotube powder and pure water; By weight percentage: 10-25% silicon nitride powder with a particle size of 1-10 micrometers, 25-35% water-soluble phenolic resin, 1-4% octylbenzene polyoxyethylene ether, 5-10% single-walled carbon nanotube powder with a particle size of 10-30 nanometers, and 30-50% pure water; or The first soaking solution was replaced with: triammonium phosphate, water-soluble phenolic resin, octanol polyoxyethylene ether, single-walled carbon nanotube powder, and pure water; By weight percentage: 10-25% triammonium phosphate powder with a particle size of 1-10 micrometers, 20-35% water-soluble phenolic resin, 1-4% octanol polyoxyethylene ether, 10-20% single-walled carbon nanotube powder with a particle size of 10-30 nanometers, and 30-50% pure water.

2. The method for manufacturing a carbon fiber rigid felt cylinder according to claim 1, characterized in that, Before step S10, the process further includes making a total preform using carbon fiber short filaments and cutting the total preform into a first carbon fiber preform and a second carbon fiber preform, wherein the ratio of the length of the first carbon fiber preform to the length of the second carbon fiber preform is between 3:7 and 3:

2.

3. The method for manufacturing a carbon fiber rigid felt cylinder according to claim 2, characterized in that, The cutting surface of the precast body is inclined, and the connection points of the inner cylinder and the outer cylinder are staggered.

4. The method for manufacturing a carbon fiber rigid felt cylinder according to any one of claims 1 to 3, characterized in that, The heat treatment includes a curing stage and a graphitization stage.

5. The method for manufacturing a carbon fiber rigid felt cylinder according to claim 4, characterized in that, The curing stage includes a moisture evaporation stage and a resin curing stage.

6. The method for manufacturing a carbon fiber rigid felt cylinder according to claim 5, characterized in that, The steps of the moisture evaporation stage include: baking in an oven, with the temperature controlled at 50-100℃ and the time controlled at 1-5 hours.

7. The method for manufacturing a carbon fiber rigid felt cylinder according to claim 5, characterized in that, The steps of the resin curing stage include: heating to 120-190℃, baking for 1-4 hours while the mold is continuously rotated.

8. The method for manufacturing a carbon fiber rigid felt cylinder according to claim 4, characterized in that, The graphitization process includes: sending the cured pre-product into a high-temperature furnace for graphitization.

9. The method for manufacturing a carbon fiber rigid felt cylinder according to claim 8, characterized in that, The cured hard felt cylinder preforms are then placed in a high-temperature furnace at 2200℃ to 2800℃ for graphitization treatment.

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