Ultrathin carbon fiber felt and preparation method thereof

Abstract

The invention discloses an ultrathin carbon fiber felt and a preparation method thereof, and relates to the technical field of composite materials. According to the method, the fiber amount of the ultrathin carbon fiber felt is controlled by adopting the electrostatic flocking technology and controlling the flocking voltage and the flocking time, and due to the fact that the uniformity of the electric field is high and easy to control, the high-precision uniformity of the ultrathin carbon fiber felt can be achieved, and the ultrathin carbon fiber felt with lower surface density can be prepared. According to the invention, the problems of tedious procedures and environmental protection of current wet-process forming of the carbon fiber felt can be solved, and the problem of overhigh surface density of the ultrathin carbon fiber felt can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, and in particular to an ultra-thin carbon fiber felt and a preparation method thereof. Background Art

[0002] Carbon fiber felt is a non-woven thin layer material made from chopped carbon fiber filaments. It has an extremely high specific surface area and low surface density. Due to the thermal and electrical conductivity of carbon fiber, it has broad application prospects in the fields of structural material reinforcement and toughening, electromagnetic shielding materials, etc.

[0003] Traditionally, carbon fiber felt is generally formed by wet method, that is, using short-cut fibers to make water slurry, applying glue and drying the slurry similar to papermaking process. This process involves multiple washing operations, which is cumbersome and consumes a lot of water. The drying process consumes a lot of electricity or heat energy, which poses certain environmental problems. In addition, the minimum surface density of carbon fiber felt formed by wet method can generally only reach 20g / m 2 It is difficult to achieve a uniform thin felt with a lower surface density (such as 10g / m 2 The following) cannot meet the specific application requirements for ultra-thin carbon fiber felt in the field of composite materials. Summary of the invention

[0004] The purpose of the present invention is mainly to address the cumbersome process and environmental protection issues of the current wet-forming carbon fiber felt, as well as the problem of excessively high surface density of ultra-thin carbon fiber felt. By adopting electrostatic flocking technology, the flocking voltage and flocking time are controlled to achieve control of the fiber amount of the carbon fiber felt. Since the electric field is highly uniform and easy to control, high-precision uniformity of the ultra-thin carbon fiber felt can be achieved, and ultra-thin carbon fiber felt with lower surface density can be prepared.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing an ultra-thin carbon fiber felt comprises the following steps:

[0007] 1) Unwinding the release paper and spraying a setting agent on the release paper;

[0008] 2) The release paper enters the electrostatic flocking area, short-cut carbon fibers are selected and evenly placed at the flocking positive electrode, the flocking voltage and flocking time are set, and the release paper is flocked;

[0009] 3) The flocked release paper enters the drying platform area for drying and solvent removal;

[0010] 4) The release paper after the solvent removal enters a cooling zone and is cooled to room temperature to obtain a release paper with carbon fiber felt;

[0011] 5) The release paper with the carbon fiber felt enters the winding area, and the ultra-thin carbon fiber felt protected by the release paper is obtained by winding. The release paper can be removed as needed when in use.

[0012] Furthermore, the setting agent is a commercially available fiber setting agent, or an alcohol or acetone solution containing epoxy resin.

[0013] Furthermore, the spraying amount of the setting agent is set according to the surface density of the carbon fiber felt to be prepared, and is 5%-20% of the surface density of the carbon fiber felt to be prepared.

[0014] Furthermore, the length of the chopped carbon fiber is 0.5-5 mm.

[0015] Furthermore, the flocking voltage is set to 10-25KV, and the flocking time is set to 5-30s.

[0016] Furthermore, the cooling zone adopts air cooling or water cooling.

[0017] An ultra-thin carbon fiber felt is prepared by the above method, and the surface density of the ultra-thin carbon fiber felt is 1-10g / m 2 .

[0018] The method of the present invention has the following advantages:

[0019] 1. Simplified process: Compared with the traditional wet-molded carbon fiber felt preparation process, the method of the present invention omits multiple cumbersome water washing processes, making the production process more simplified. This not only reduces the number of processes, but also reduces production costs and energy consumption, and is conducive to improving production efficiency.

[0020] 2. Environmentally friendly: The preparation process of traditional wet-molded carbon fiber felt requires the use of a large amount of solvents and chemicals, and produces environmental pollution problems such as wastewater and waste gas. The method of the present invention does not require a water washing step, which reduces the consumption of water resources, while reducing the use of chemicals and waste emissions, significantly improving the environmental friendliness of the production process.

[0021] 3. Production flexibility: The method of the present invention can realize the preparation of ultra-thin carbon fiber felts of different specifications on one production line by controlling the flocking voltage and flocking time. This means that the thickness and density of the ultra-thin carbon fiber felt can be flexibly adjusted according to demand to meet the requirements of material properties in different application fields, thereby improving the flexibility and applicability of production.

[0022] 4. High uniformity: With the electrostatic flocking technology, the flocking electric field has high uniformity, which can ensure the uniform distribution of the fiber amount of the ultra-thin carbon fiber felt. This is very important for the preparation of composite materials, and can provide consistency and reliability of material performance to meet high precision and high quality requirements.

[0023] 5. Lower surface density: Due to the use of electrostatic flocking technology, the surface density can be prepared to 1-10g / m 2 Ultra-thin carbon fiber felt.

[0024] In summary, the method of the present invention simplifies the process, is environmentally friendly, and has multiple advantages such as production flexibility, high uniformity and lower surface density. This makes the method have broad application prospects in the field of ultra-thin carbon fiber felt preparation and is expected to promote the development and application of carbon fiber materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of preparing thin carbon fiber felt according to the present invention. DETAILED DESCRIPTION

[0026] In order to make the various technical features and advantages or technical effects in the above technical solutions of the present invention more obvious and easy to understand, they are described in detail below with reference to the accompanying drawings.

[0027] Example 1

[0028] This embodiment specifically discloses a method for preparing an ultra-thin carbon fiber felt. Figure 1 The preparation schematic diagram shown specifically includes the following steps:

[0029] 1) Release paper is unrolled and a setting agent is sprayed on the release paper. The setting agent is a commercially available fiber setting agent, and the spraying amount is 10% of the carbon fiber felt to be prepared.

[0030] 2) The release paper enters the electrostatic flocking area. The electrostatic flocking area is generated by the flocking positive plate and the flocking negative plate connected to the DC high voltage power supply. It is located between the positive and negative plates, and the release paper is located near the flocking negative plate. Select short-cut carbon fibers with a length of about 2 mm and place them evenly near the flocking positive plate. Set the flocking voltage to 20 kV and the flocking time to 20 s. Perform the flocking operation on the release paper. Figure 1 shown.

[0031] 3) The flocked release paper enters the drying platform area for drying and solvent removal.

[0032] 4) The release paper after the solvent is removed enters a cooling zone for air cooling and is cooled to room temperature to obtain a release paper with carbon fiber felt.

[0033] 5) The release paper with the carbon fiber felt enters the winding area, and the ultra-thin carbon fiber felt protected by the release paper is obtained by winding. The release paper can be removed as needed when in use.

[0034] Example 2

[0035] This embodiment also discloses a method for preparing an ultra-thin carbon fiber felt. The operation steps and electrostatic flocking method are basically the same as those in Example 1, except that: the setting agent is an alcohol solution containing epoxy resin, and the spraying amount is 20% of the carbon fiber felt to be prepared; short chopped carbon fibers with a length of about 5 mm are selected, the flocking voltage is set to 25 kV, and the flocking time is set to 5 s; and the cooling zone is water-cooled.

[0036] Example 3

[0037] This embodiment also discloses a method for preparing an ultra-thin carbon fiber felt. The operation steps and electrostatic flocking method are basically the same as those in Example 1, except that: the setting agent is an acetone solution containing epoxy resin, and the spraying amount is 5% of the carbon fiber felt to be prepared; short chopped carbon fibers with a length of about 0.5 mm are selected, the flocking voltage is set to 10 kV, and the flocking time is set to 30 s; and the cooling zone is water-cooled.

[0038] The surface densities of the ultra-thin carbon fiber felts prepared in Examples 1-3 were 8 g / m 2 , 2g / m 2 , 5g / m 2 .

[0039] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Appropriate modifications or equivalent substitutions of the technical solutions of the present invention made by ordinary technicians in the field should all be included in the protection scope of the present invention. The protection scope of the present invention shall be based on what is defined in the claims.

Claims

1. A method for preparing an ultra-thin carbon fiber felt, characterized in that: The following steps are involved: 1) Unwinding the release paper and spraying a setting agent on the release paper; 2) The release paper enters the electrostatic flocking area, short-cut carbon fibers are selected and evenly placed at the flocking positive electrode, the flocking voltage and flocking time are set, and the release paper is flocked; 3) The flocked release paper enters the drying platform area for drying and solvent removal; 4) The release paper after the solvent removal enters a cooling zone and is cooled to room temperature to obtain a release paper with carbon fiber felt; 5) The release paper with the carbon fiber felt enters the winding area, and the ultra-thin carbon fiber felt protected by the release paper is obtained by winding. The release paper can be removed as needed when in use.

2. The preparation method according to claim 1, characterized in that The setting agent is a commercially available fiber setting agent.

3. The preparation method according to claim 1, characterized in that: The setting agent is an alcohol solution dissolved with epoxy resin.

4. The preparation method according to claim 1, characterized in that: The setting agent is an acetone solution dissolved with epoxy resin.

5. The preparation method according to claim 1, characterized in that: The spraying amount of the setting agent is 5%-20% of the surface density of the carbon fiber felt to be prepared.

6. The preparation method according to claim 1, characterized in that: The length of the chopped carbon fiber is 0.5-5 mm.

7. The preparation method according to claim 1, characterized in that: The set flocking voltage is 10-25KV and the flocking time is 5-30s.

8. The preparation method according to claim 1, characterized in that: The cooling zone adopts air cooling.

9. The preparation method according to claim 1, characterized in that: The cooling zone is water-cooled.

10. An ultra-thin carbon fiber felt prepared by the preparation method according to any one of claims 1 to 9, characterized in that: The surface density of the ultra-thin carbon fiber felt is 1-10g / m 2 .

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