Preparation method for preparing carbon cloth by glue-free process

Abstract

The invention discloses a method for manufacturing carbon cloth through a glue-free process. The method comprises the steps that nylon fabric with claws and fluffy fiber bundles is provided, activated carbon particles are evenly spread on the fiber bundle face of the first nylon fabric, self-bonding is achieved through pressing of the claw face of the second nylon fabric, and the carbon cloth without being cut and sewn is manufactured. The method does not need an adhesive or hot pressing, simplifies the production process, avoids the emission of toxic gases, and reduces the cost. The porosity uniformity of the obtained carbon cloth is improved by 30% or above, the filtering efficiency reaches 95% or above, and the carbon cloth is suitable for air purifier filtering materials and has the advantages of being efficient, environmentally friendly and economical.

Description

Technical Field

[0001] This invention relates to the technical field of carbon cloth, and in particular to a method for preparing carbon cloth using a glue-free process. Background Technology

[0002] The air filtration consumables industry has experienced rapid growth in recent years due to escalating environmental pollution and increased public concern about indoor air quality. Carbon cloth, as a highly efficient filtration material, is widely used in air purifiers, industrial waste gas treatment, and protective equipment due to its excellent adsorption performance and large specific surface area. Traditional carbon cloth manufacturing processes primarily rely on mixing activated carbon particles with binders (such as epoxy resin) and then fixing them onto a substrate through hot pressing and curing to form a composite material with filtration capabilities. In recent years, improvements in manufacturing processes have focused on increasing the porosity, adsorption efficiency, and production efficiency of carbon cloth, while simultaneously striving to reduce environmental pollution and production costs. Some studies have attempted to improve carbon cloth performance by optimizing binder formulations or improving hot pressing processes, such as using low-volatile resins or introducing nanoscale carbon materials to enhance adsorption capacity. However, these technological advancements are still limited by the inherent defects of traditional processes, making it difficult to achieve a comprehensive breakthrough in production efficiency, environmental friendliness, and product quality.

[0003] While traditional carbon fiber fabric manufacturing processes meet air filtration requirements to some extent, they have significant shortcomings, particularly in terms of process complexity, environmental impact, and the stability of filtration performance. First, traditional processes require premixing epoxy resin and carbon particles before hot-pressing and curing, involving multiple steps that are not only time-consuming and energy-intensive but also increase production costs. Second, epoxy resin requires stringent storage and use conditions, such as storage at -18°C, and has a short shelf life, increasing the difficulty of raw material management. Furthermore, epoxy resin releases toxic gases (such as styrene) when heated, necessitating additional waste gas treatment equipment, further increasing production costs and environmental burden. Most importantly, carbon particles are prone to agglomeration in the binder, leading to uneven porosity distribution and affecting airflow uniformity and filtration efficiency. Summary of the Invention

[0004] This application provides a method for preparing carbon cloth using a glue-free process, comprising the following steps: Step S1. Provide a first nylon fabric and a second nylon fabric, wherein both the first nylon fabric and the second nylon fabric have a front and a back side, the front side having densely arranged hooks with a hook density of 200-400 hooks / m. 3 The hook height is 0.5-1.5 mm, and the reverse side has a fluffy fiber bundle with a fiber bundle density of 300-600 fibers / cm², a fiber length of 1-3 mm, and a fiber diameter of 10-50 μm. Step S2. Lay the first nylon fabric flat on a horizontal workbench, ensuring the fiber bundles face upwards. Use a vibrating sieving device with a vibration frequency of 50-100 Hz and a screen aperture of 0.1-0.5 mm to evenly spread carbon particles onto the fiber bundles. The carbon particles have a particle size of 0.05-0.5 mm and a spreading rate of 100-300 g / m². 2 This allows the carbon particles to be naturally dispersed and embedded in the gaps through the loose structure of the fiber bundle; Step S3. Align the hooks of the second nylon fabric with the hooks facing down and cover the first nylon fabric that has been laid with carbon particles. Use a steel plate to apply pressure evenly at 0.1-0.5 MPa for 10-30 seconds to make the hooks hook and the fiber bundles hook together to achieve self-adhesion and form carbon cloth. Step S4. Remove the steel plate, check the surface flatness and carbon particle distribution uniformity of the carbon cloth, and obtain a finished carbon cloth that does not require cutting or sewing. In a preferred technical solution for a method of preparing carbon cloth using a glue-free process, the shape of the hook is selected from J-shaped or mushroom-shaped, and the diameter of the tip of the hook is 0.2-0.8 mm. In a preferred technical solution for preparing carbon cloth using a glue-free process, the carbon particles are activated carbon particles with a specific surface area of ​​500-1500 m². 2 / g, pore volume is 0.3-0.8 cm³ 3 / g. As a preferred technical solution for the preparation method of carbon cloth using a glue-free process, in step S2, the screen of the vibrating screening device is made of stainless steel, and the screen aperture uniformity error is less than 5%. In a preferred technical solution for a method of preparing carbon cloth using a glue-free process, in step S3, the surface roughness Ra of the steel plate is 0.8-3.2 μm, and the temperature of the steel plate is maintained at 20-30℃ during the pressure application process. In a preferred technical solution for a method of preparing carbon cloth using a glue-free process, the first nylon fabric and the second nylon fabric have the same fiber bundle density, and the fibers of the fiber bundle are made of nylon 6 or nylon 66. As a preferred technical solution for the preparation method of carbon cloth using a glue-free process, the carbon cloth is used as a filter material for air purifiers and is suitable for adsorbing air particles with a particle size of 0.1-10 μm.

[0005] This invention provides a glue-free method for producing carbon fiber cloth, which offers significant advantages over traditional processes. This method utilizes the self-adhesive properties of nylon fabric's hooks and fiber bundles to achieve uniform fixation of activated carbon particles, eliminating the need for adhesives such as epoxy resins. This avoids the emission of volatile toxic gases (such as styrene) and eliminates the need for waste gas treatment equipment, achieving green and environmentally friendly production. Simultaneously, this process eliminates hot pressing and cutting / sewing steps, shortening the production cycle by approximately 50% and significantly reducing production costs and energy consumption. The natural dispersion of activated carbon particles within the loose fiber bundles prevents agglomeration, increasing porosity uniformity by at least 30%, and improving airflow uniformity and filtration efficiency to over 95% (0.3 μm particles), a significant advantage over the 85%-90% of traditional processes. Furthermore, the glue-free process eliminates the need for low-temperature adhesive storage, simplifying raw material management. The production process is completed at ambient temperature and pressure, making it suitable for preparing filter materials for household to industrial-grade air purifiers, demonstrating high efficiency, environmental friendliness, and economic advantages. Attached Figure Description

[0006] Figure 1 A schematic diagram of the structure for fabricating carbon cloth using a glue-free process; Figure 2 This is a magnified view of a portion of Figure 1.

[0007] Reference numerals: 1. First nylon fabric; 2. Second nylon fabric; 3. Fiber bundle; 4. Hook; 5. Carbon particles. Detailed Implementation

[0008] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0009] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0010] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single embodiment or an embodiment selectively excluded from other embodiments.

[0011] Example Example 1 Step S1: Provide a first nylon fabric and a second nylon fabric, both made of nylon 6 material. The front side of both the first and second nylon fabrics has densely arranged J-shaped hooks, with a hook density of 200 hooks / m². 3 The hook height is 0.5 mm, and the hook tip diameter is 0.2 mm; the reverse side has a fluffy fiber bundle with a fiber bundle density of 300 fibers / cm², a fiber length of 1 mm, and a fiber diameter of 10 μm. The nylon fabric measures 1 m × 1 m, and its surface is cleaned to remove impurities. Step S2: Lay the first nylon fabric flat on a stainless steel horizontal workbench, ensuring the fiber bundles face upwards. Use a stainless steel vibrating sieve with a screen aperture of 0.1 mm, an aperture uniformity error of 3%, and a vibration frequency set to 50 Hz. Add activated carbon particles with a particle size of 0.05 mm (specific surface area of ​​500 m²). 2 / g, pore volume is 0.3 cm³ 3 (g) Spread evenly on the surface of the fiber bundle, with a spreading amount of 100 g / m. 2 During the spreading process, the activated carbon particles naturally embed themselves into the gaps through the loose structure of the fiber bundles, and the vibration time is 5 minutes to ensure uniform particle distribution. Step S3: Align the hooks of the second nylon fabric face down and cover it over the first nylon fabric with the activated carbon particles already laid on it. Using a steel plate with a surface roughness Ra of 0.8 μm, apply a uniform pressure of 0.1 MPa for 10 seconds, while maintaining the temperature of the steel plate at 20°C. Through the pressure, the hooks and fiber bundles hook together to achieve self-adhesion, forming a carbon cloth with a peel strength of 15 N / mm. Step S4: Remove the steel plate and use an optical microscope to check the surface smoothness of the carbon cloth and the uniformity of the activated carbon particle distribution. The standard deviation of the porosity distribution is 8%. The resulting carbon cloth does not need to be cut or sewn and can be used directly as a finished product with a size of 1 m × 1 m. It is suitable for adsorbing air particles with a particle size of 0.1-10 μm. Example 2 Step S1: Provide a first nylon fabric and a second nylon fabric, both made of nylon 66. The front side of both the first and second nylon fabrics has densely arranged mushroom-shaped hooks, with a hook density of 300 hooks / m². 3 The hook height is 1.0 mm, and the hook tip diameter is 0.5 mm; the reverse side has a fluffy fiber bundle with a fiber bundle density of 450 fibers / cm², a fiber length of 2 mm, and a fiber diameter of 30 μm. The nylon fabric measures 1.5 m × 1.5 m, and the surface is ultrasonically cleaned to remove oil and dust. Step S2: Lay the first nylon fabric flat on a horizontal workbench with the fiber bundles facing upwards. Use a stainless steel vibrating sieve with a screen aperture of 0.3 mm, an aperture uniformity error of 4%, and a vibration frequency set to 75 Hz. Then, use activated carbon particles with a particle size of 0.2 mm (specific surface area of ​​1000 m²). 2 / g, pore volume is 0.5 cm³ 3 (g) Spread evenly on the fiber bundle surface at a rate of 200 g / m². 2 The vibration time was 7 minutes, and the activated carbon particles naturally dispersed through the gaps in the fiber bundles without obvious agglomeration. Step S3: Align the hooks of the second nylon fabric with their claws facing down and cover the first nylon fabric. Using a steel plate with a surface roughness Ra of 2.0 μm, apply a uniform pressure of 0.3 MPa for 20 seconds, while maintaining the temperature of the steel plate at 25°C. The claws and fiber bundles achieve self-adhesion through pressure, achieving a peel strength of 20 N / mm. Step S4: Remove the steel plate and use an airflow tester (airflow velocity of 1 m / s) to test the uniformity of airflow from the carbon cloth. The standard deviation of the porosity distribution is 7%, and it passes the 0.3 μm particle filtration efficiency test, achieving a filtration efficiency of 95%. The resulting carbon cloth requires no cutting or sewing, has a size of 1.5 m × 1.5 m, and is suitable for air purifier filter materials. Example 3 Step S1: Provide a first nylon fabric and a second nylon fabric, both made of nylon 6 material. The first and second nylon fabrics have J-shaped hooks on their front sides, with a hook density of 400 hooks / m². 3 The hook height is 1.5 mm, and the hook tip diameter is 0.8 mm; the reverse side has a fluffy fiber bundle with a fiber bundle density of 600 fibers / cm², a fiber length of 3 mm, and a fiber diameter of 50 μm. The nylon fabric measures 2 m × 2 m, and its surface is treated with plasma cleaning to enhance surface activity. Step S2: Lay the first nylon fabric flat on a horizontal workbench with the fiber bundles facing upwards. Use a stainless steel vibrating sieve with a screen aperture of 0.5 mm, an aperture uniformity error of 2%, and a vibration frequency set to 100 Hz. Add activated carbon particles with a particle size of 0.5 mm (specific surface area of ​​1500 m²). 2 / g, pore volume is 0.8 cm³ 3 (g) Spread evenly on the fiber bundle surface at a rate of 300 g / m 2 The vibration time is 10 minutes to ensure that the activated carbon particles are evenly embedded in the gaps of the fiber bundle. Step S3: Align the hooks of the second nylon fabric face down and cover the first nylon fabric. Using a steel plate with a surface roughness Ra of 3.2 μm, apply a uniform pressure of 0.5 MPa for 30 seconds, while maintaining the temperature of the steel plate at 30°C. The hooks and fiber bundles achieve self-adhesion through pressure, achieving a peel strength of 25 N / mm. Step S4: Remove the steel plate and use a scanning electron microscope to check the surface flatness and particle distribution of the carbon cloth. The standard deviation of the porosity distribution is 6%. The filtration efficiency of 0.3 μm particles is 98%. The resulting carbon cloth does not require cutting or sewing, has a size of 2 m × 2 m, and is suitable for industrial air purification equipment. Example 4 Step S1: Provide a first nylon fabric and a second nylon fabric, both made of nylon 66. The first and second nylon fabrics have mushroom-shaped hooks on their front sides, with a hook density of 250 hooks / m². 3 The hook height is 0.8 mm, and the hook tip diameter is 0.4 mm. The reverse side has a fluffy fiber bundle with a fiber bundle density of 400 fibers / cm², a fiber length of 1.5 mm, and a fiber diameter of 20 μm. The nylon fabric measures 1.2 m × 1.2 m, and the surface is cleaned with deionized water to remove impurities. Step S2: Lay the first nylon fabric flat on a horizontal workbench with the fiber bundles facing upwards. Use a stainless steel vibrating sieve with a screen aperture of 0.2 mm, an aperture uniformity error of 3.5%, and a vibration frequency set to 60 Hz. Add activated carbon particles with a particle size of 0.1 mm (specific surface area of ​​800 m²). 2 / g, pore volume is 0.4 cm³ 3 The fiber bundle surface is evenly spread with a spreading amount of 150 g / m². 2 The vibration time was 6 minutes, and the activated carbon particles were evenly dispersed in the gaps between the fiber bundles. Step S3: Align the hooks of the second nylon fabric face down and cover the first nylon fabric. Using a steel plate with a surface roughness Ra of 1.6 μm, apply a uniform pressure of 0.2 MPa for 15 seconds, while maintaining the temperature of the steel plate at 22°C. The hooks and fiber bundles achieve self-adhesion through pressure, achieving a peel strength of 18 N / mm. Step S4: Remove the steel plate and use an airflow tester (airflow velocity of 1.5 m / s) to test the uniformity of airflow from the carbon cloth. The standard deviation of porosity distribution is 7.5%, and the filtration efficiency for 0.3 μm particles reaches 96%. The resulting carbon cloth requires no cutting or sewing, has a size of 1.2 m × 1.2 m, and is suitable for home air purifiers.

[0012] Comparison Example Compare with Example 1 Step 1: Provide a first nylon fabric and a second nylon fabric, both made of nylon 6 material, with dimensions of 1 m × 1 m, and their surfaces are cleaned to remove impurities. The front sides of both the first and second nylon fabrics have densely arranged J-shaped hooks, with a hook density of 200 hooks / m. 3 The hook height is 0.5 mm and the hook tip diameter is 0.2 mm; the reverse side has a fluffy fiber bundle with a fiber bundle density of 300 fibers / cm², a fiber length of 1 mm, and a fiber diameter of 10 μm.

[0013] Step 2: Lay the first nylon fabric flat on a horizontal workbench, ensuring the fiber bundles face upwards. Use a vibrating sieve device at a vibration frequency of 50 Hz and a sieve mesh size of 0.1 mm to separate activated carbon particles with a particle size of 0.05 mm (specific surface area of ​​500 m²). 2 / g, pore volume is 0.3 cm³ 3 (g) Spread evenly on the surface of the fiber bundle, with a spreading amount of 100 g / m. 2 After spreading, spray with epoxy resin adhesive solution (epoxy resin to hardener mass ratio 10:1, adhesive spraying amount 50 g / m²). 2 The activated carbon particles adhere to the surface of the fiber bundle, and the vibration time is 5 minutes.

[0014] Step 3: Align the hook side of the second nylon fabric downwards and cover it over the first nylon fabric that has been laid with activated carbon particles and sprayed with adhesive. Using a steel plate with a surface roughness Ra of 0.8 μm, apply a uniform pressure of 0.1 MPa for 10 seconds, keeping the temperature of the steel plate at 20°C, so that the hooks initially hook into the fiber bundle.

[0015] Step 4: Place the stacked nylon fabric in a hot press, set the hot pressing temperature to 120℃, the pressure to 0.1MPa, and the hot pressing time to 60 seconds to cure the epoxy resin, enhancing the adhesion between the activated carbon particles and the fibers, achieving a peel strength of 14 N / mm. During the hot pressing process, a ventilation system should be used to handle the volatilized styrene gas.

[0016] Step 5: After cooling to room temperature, the surface smoothness of the carbon cloth and the uniformity of activated carbon particle distribution were examined using an optical microscope. It was found that the activated carbon particles were locally agglomerated due to the binder, and the standard deviation of the porosity distribution was 13%. The resulting carbon cloth needs to be trimmed at the edges, with a size of 1 m × 1 m, and the filtration efficiency for 0.3 μm particles is 89%.

[0017] Examples 1 to 4 describe in detail a method for producing carbon cloth using a glue-free process, demonstrating the versatility and applicability of the method through different parameter settings. Example 1 uses a low density (200 hooks / m²). 3 The process, employing 300 fiber bundles / cm², small-diameter (0.05 mm) activated carbon granules, and a low-pressure (0.1 MPa) process, is suitable for small-scale production. With a porosity distribution standard deviation of 8% and a filtration efficiency of 95%, it demonstrates high efficiency and uniformity. Example 2 involves increasing the hook density (300 hooks / m²). 3 The fiber bundle density (450 fibers / cm²) and activated carbon particle size (0.2 mm) were adjusted, and the application rate was increased to 200 g / m². 2 The pressure was increased to 0.3 MPa, suitable for medium-scale production. The standard deviation of the porosity distribution was 7%, and the filtration efficiency remained at 95%, demonstrating the process's adaptability to parameter changes. Example 3 used the highest density (400 hooks / m²). 3 With a fiber bundle density of 600 fibers / cm², a maximum particle size of 0.5 mm, and a maximum pressure of 0.5 MPa, it is suitable for large-scale industrial production. The standard deviation of porosity distribution is as low as 6%, and the filtration efficiency reaches 98%, indicating that high density and high pressure can further optimize performance. Example 4 uses medium parameters (250 hooks / m²). 3 With 400 fiber bundles / cm², a particle size of 0.1 mm, and a pressure of 0.2 MPa, the standard deviation of porosity distribution is 7.5%, and the filtration efficiency is 96%, making it suitable for household air purifiers and demonstrating the flexibility of the process. Overall, Examples 1 to 4, by adjusting parameters such as hook and fiber bundle density, activated carbon particle size, spreading amount, and pressure, verified the stability and efficiency of this adhesive-free process in different application scenarios. The porosity uniformity is superior to traditional processes (improved by at least 30%), and the absence of adhesives and hot pressing simplifies the production process and reduces environmental impact.

[0018] Example 1: Using hooks on nylon fabric (200 hooks / m) 3 The self-adhesive properties of the fiber bundles (300 fibers / cm²) allow for the uniform spreading and fixation of 0.05 mm activated carbon particles (spreading amount 100 g / m²). 2 This method uses only 0.1 MPa pressure for 10 seconds, requiring no adhesive or hot pressing, resulting in a simple process with a porosity distribution standard deviation of 8% and a filtration efficiency of 95% for 0.3 μm particles. Comparative Example 1, while using the same nylon fabric specifications and activated carbon particle parameters, additionally sprayed epoxy resin adhesive (50 g / m²) after the particles were spread. 2The process involved hot-pressing at 120°C for 60 seconds to cure the material, which added hot-pressing and exhaust gas treatment steps, leading to localized particle agglomeration. This increased the standard deviation of the porosity distribution to 13%, and reduced the filtration efficiency to 89%. The adhesive-free self-adhesive process of Example 1 avoids the agglomeration problem caused by adhesives, significantly improving porosity uniformity and filtration efficiency. Furthermore, it eliminates the need for low-temperature storage of adhesives or treatment of toxic gases (such as styrene), reducing production costs and environmental burden. This comparison highlights that Example 1 achieves a more efficient, environmentally friendly, and simplified method for preparing carbon cloth through self-adhesive technology.

[0019] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing carbon cloth using a glue-free process, characterized in that, Includes the following steps: Step S1. Provide a first nylon fabric and a second nylon fabric, wherein both the first nylon fabric and the second nylon fabric have a front and a back side, the front side having densely arranged hooks with a hook density of 200-400 hooks / m. 3 The hook height is 0.5-1.5 mm, and the reverse side has a fluffy fiber bundle with a fiber bundle density of 300-600 fibers / cm², a fiber length of 1-3 mm, and a fiber diameter of 10-50 μm. Step S2. Lay the first nylon fabric flat on a horizontal workbench, ensuring the fiber bundles face upwards. Use a vibrating sieving device with a vibration frequency of 50-100 Hz and a screen aperture of 0.1-0.5 mm to evenly spread carbon particles onto the fiber bundles. The carbon particles have a particle size of 0.05-0.5 mm and a spreading rate of 100-300 g / m². 2 This allows the carbon particles to be naturally dispersed and embedded in the gaps through the loose structure of the fiber bundles; Step S3. Align the hooks of the second nylon fabric with the hooks facing down and cover the first nylon fabric that has been laid with carbon particles. Use a steel plate to apply pressure evenly at 0.1-0.5 MPa for 10-30 seconds to make the hooks hook and the fiber bundles hook together to achieve self-adhesion and form carbon cloth. Step S4. Remove the steel plate, check the surface flatness and carbon particle distribution uniformity of the carbon cloth, and obtain a finished carbon cloth that does not require cutting or sewing.

2. The method for preparing carbon cloth using the glue-free process according to claim 1, characterized in that, The shape of the hook is selected from J-shaped or mushroom-shaped, and the diameter of the tip of the hook is 0.2-0.8 mm.

3. The method for preparing carbon cloth using the glue-free process according to claim 1, characterized in that, The carbon particles are activated carbon particles with a specific surface area of ​​500-1500 m². 2 / g, pore volume is 0.3-0.8 cm³ 3 / g.

4. The method for preparing carbon cloth using the glue-free process according to claim 1, characterized in that, In step S2, the screen of the vibrating screening device is made of stainless steel, and the screen aperture uniformity error is less than 5%.

5. The method for preparing carbon cloth using the glue-free process according to claim 1, characterized in that, In step S3, the surface roughness Ra of the steel plate is 0.8-3.2 μm, and the temperature of the steel plate is maintained at 20-30℃ during the pressure application process.

6. The method for preparing carbon cloth using the glue-free process according to claim 1, characterized in that, The first nylon fabric and the second nylon fabric have the same fiber bundle density, and the fibers of the fiber bundle are made of nylon 6 or nylon 66.

7. The method for preparing carbon cloth using the glue-free process according to claim 1, characterized in that, The carbon cloth is used as a filter material in air purifiers and is suitable for adsorbing air particles with a particle size of 0.1-10 μm.

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