A bamboo charcoal fiber composite material and preparation method thereof

Abstract

The invention discloses a bamboo charcoal fiber composite material and a preparation method thereof, and relates to the field of fiber materials. The bamboo charcoal fiber composite material comprises a core layer and two surface layers located on the upper and lower surfaces of the core layer, wherein the surface layer is made of 35-45wt%3D-5D low-melting-point fiber, 8-12wt%4D-8D bamboo charcoal fiber and surplus 10D-20D bamboo charcoal fiber, and the core layer is made of 30-40wt%3D-5D low-melting-point fiber, 32-38wt%6D-8D three-dimensional hollow fiber and surplus 10D-20D three-dimensional hollow fiber. The bamboo charcoal fiber composite material of the present application has the characteristics of softness, wear resistance, high support strength and good resilience, and can effectively extend the service life of the bamboo charcoal fiber composite material.

Description

Technical Field

[0001] The present application relates to the field of fiber materials, and in particular to a bamboo charcoal fiber composite material and a preparation method thereof. Background Art

[0002] As a new type of environmentally friendly material, bamboo charcoal fiber has excellent adsorption capacity due to its unique microporous structure and carbon-rich properties. It can effectively remove odors and harmful gases in the air and show good antibacterial and deodorizing effects. However, bamboo charcoal fiber has poor resilience. When the fiber mat is made directly from bamboo charcoal fiber, the fiber mat has poor resilience, which is not conducive to improving the durability of the fiber mat. Summary of the invention

[0003] In order to improve the problem of poor resilience of fiber mats made of bamboo charcoal fibers in the related art, the present application provides a bamboo charcoal fiber composite material and a preparation method thereof.

[0004] In the first aspect, the present application provides a bamboo charcoal fiber composite material adopting the following technical solution:

[0005] A bamboo charcoal fiber composite material comprises a core layer and two surface layers located on the upper and lower surfaces of the core layer, wherein the surface layers are made of 35-45wt% 3D-5D low-melting point fibers, 8-12wt% 4D-8D bamboo charcoal fibers and the remainder 10D-20D bamboo charcoal fibers, and the core layer is made of 30-40wt% 3D-5D low-melting point fibers, 32-38wt% 6D-8D three-dimensional hollow fibers and the remainder 10D-20D three-dimensional hollow fibers.

[0006] The bamboo charcoal fiber composite material in the present application is a composite material consisting of a surface layer, a core layer and a surface layer from top to bottom. The main material of the surface layer is bamboo charcoal fiber. The microporous structure of bamboo charcoal fiber is very developed, which can provide a strong adsorption capacity and effectively adsorb odors in the air to achieve the purpose of deodorization. In addition, bamboo charcoal fiber can release negative ions, which can change the charge balance inside and outside bacterial cells, affect the metabolic activities of bacteria, and cause them to die or lose their reproductive ability, that is, bamboo charcoal fiber also has antibacterial effect. The main material of the core layer is three-dimensional hollow fiber. The hollow structure of the three-dimensional hollow fiber can give the bamboo charcoal composite material elasticity, thereby obtaining a bamboo charcoal fiber composite material with both antibacterial deodorization and elastic properties.

[0007] Among them, the bamboo charcoal fiber in the surface layer includes two specifications of bamboo charcoal fiber, 4D-8D and 10D-20D. The 4D-8D bamboo charcoal fiber can give the surface layer a certain softness and skin-friendly feeling, which is beneficial to improving comfort, while the 10D-20D bamboo charcoal fiber has good wear resistance, which is beneficial to improving the durability of the surface layer.

[0008] The three-dimensional hollow fibers in the core layer include two specifications of 6D-8D and 10D-20D. The cooperation of two different specifications of three-dimensional hollow fibers, 6D-8D and 10-20D, can improve the air permeability of the core layer. In addition, the 10-20D three-dimensional hollow fibers have stronger structural support, which improves the supporting strength and resilience of the bamboo charcoal fiber composite material.

[0009] The low melting point fiber adopts 3D-5D low melting point fiber, which is conducive to the firm bonding of bamboo charcoal fibers of different specifications and three-dimensional hollow fibers of different specifications.

[0010] In summary, the bamboo charcoal fiber composite material of the present application has the characteristics of softness, wear resistance, good air permeability, high supporting strength and good resilience.

[0011] In a specific embodiment, the cross-section of the 6D-8D three-dimensional hollow fiber is triangular, and the cross-section of the 10D-20D three-dimensional hollow fiber is circular or elliptical.

[0012] The cross-section of the 6D-8D three-dimensional hollow fiber is preferably triangular, and the cross-section of the 10D-20D three-dimensional hollow fiber is preferably circular or elliptical. The combination of the two is beneficial to further improve the air permeability of the core layer. At the same time, the cross-section of the 6D-8D three-dimensional hollow fiber is preferably triangular, which can further improve the supporting strength of the core layer while ensuring the softness of the core layer.

[0013] In some specific embodiments, the core layer has a grammage of 18-22 g / m 2 The surface layer has a grammage of 25-30 g / m 2 .

[0014] In some specific embodiments, the 3D-5D low melting point fiber is obtained by melt spinning of terminal hydroxyl saturated polyester resin, and the 4D-8D bamboo charcoal fiber, 10D-20D bamboo charcoal fiber, 6D-8D three-dimensional hollow fiber, and 10D-20D three-dimensional hollow fiber are respectively modified with isocyanate-terminated polyurethane.

[0015] In the present application, the 3D-5D low-melting point fiber contains a hydroxyl group, while the 4D-8D bamboo charcoal fiber, 10D-20D bamboo charcoal fiber, 6D-8D three-dimensional hollow fiber, and 10D-20D three-dimensional hollow fiber contain an isocyanate group after being modified with isocyanate-terminated polyurethane. In the subsequent composite heat baking process, the surface layer and the core layer can be firmly bonded, and the bonding points of the surface layer and the core layer can also be firmly bonded, which has a further enhancing effect on improving the resilience and supporting strength of the bamboo charcoal fiber composite material.

[0016] In some specific embodiments, the isocyanate-terminated polyurethane is obtained by reacting a polymeric diol with a diisocyanate in a molar ratio of (0.6-0.8):1.

[0017] In some specific embodiments, the polymeric diol is a polyester diol with a molecular weight of 2000-3000.

[0018] In the present application, the polymeric diol is preferably a polyester diol with a molecular weight of 2000-3000. Compared with the isocyanate-terminated polyurethane prepared by using polyether diol and diisocyanate, the polyester-type isocyanate-terminated polyurethane has stronger structural strength, which is beneficial to improving the resilience and supporting strength of the bamboo charcoal fiber composite material.

[0019] In some specific embodiments, the diisocyanate is an aromatic diisocyanate.

[0020] Compared with aliphatic diisocyanates, the modification of bamboo charcoal fibers and three-dimensional hollow fibers by isocyanate-terminated polyurethane prepared by aromatic diisocyanates and polymerized diols can further improve the resilience and supporting strength of bamboo charcoal fiber composites.

[0021] In the second aspect, the present application provides a method for preparing a bamboo charcoal fiber composite material using the following technical solution:

[0022] A method for preparing a bamboo charcoal fiber composite material comprises the following steps:

[0023] 3D-5D low melting point fiber, 4D-8D bamboo charcoal fiber and 10D-20D bamboo charcoal fiber are uniformly mixed according to a ratio to obtain a first mixture, and the first mixture is opened, carded and laid to form a preformed surface layer in sequence;

[0024] 3D-5D low melting point fibers, 6D-8D three-dimensional hollow fibers, and 10D-20D three-dimensional hollow fibers are uniformly mixed according to a ratio to obtain a second mixture, and the second mixture is opened, carded, and laid to form a web at one time to obtain a preformed core layer;

[0025] A layer of the preformed surface layer is laid flat on the upper and lower surfaces of the preformed core layer, and the positioning is completed.

[0026] After the product is formed, it is heat-dried at 110-135° C. and then cooled and shaped to obtain a bamboo charcoal fiber composite material.

[0027] The present application first mixes the surface layer raw materials, loosens them, combs them and then lays them out to obtain a preformed surface layer, and also mixes the core layer raw materials, loosens them, combs them and then lays them out to obtain a preformed core layer, and then stacks the preformed surface layer, preformed core layer and preformed surface layer in sequence, and then sends them into an oven for heat drying, and the heat drying temperature is controlled at 110-135°C, so that the low-melting point fiber melts and penetrates into the surface layer, the core layer and the gap between the surface layer and the core layer, and after cooling, the bonding between the different fibers of the surface layer and the core layer is achieved, and at the same time, the bonding between the surface layer and the core layer is achieved.

[0028] In some specific embodiments, in the preparation step of the preformed surface layer, a layer of isocyanate-terminated polyurethane is first evenly sprayed on the surface of the 4D-8D bamboo charcoal fiber and the 10D-20D bamboo charcoal fiber. After the isocyanate-terminated polyurethane on the surface of the 4D-8D bamboo charcoal fiber and the 10D-20D bamboo charcoal fiber is dried, it is mixed with the 3D-5D low melting point fiber obtained by melt spinning of the terminal hydroxyl saturated polyester resin to prepare the preformed surface layer.

[0029] The use of the above method to prepare the preformed surface layer is conducive to achieving firm bonding between different fibers in the surface layer, and has a promoting effect on extending the service life of the bamboo charcoal fiber composite material.

[0030] In some specific embodiments, in the preparation step of the preformed core layer, a layer of isocyanate-terminated polyurethane is first evenly sprayed on the surface of the 6D-8D three-dimensional hollow fiber and the 10D-20D three-dimensional hollow fiber. After the isocyanate-terminated polyurethane on the surface of the 6D-8D three-dimensional hollow fiber and the 10D-20D three-dimensional hollow fiber is dried, it is mixed with the 3D-5D low-melting point fiber obtained by melt spinning of a terminal hydroxyl saturated polyester resin to prepare the preformed core layer.

[0031] The use of the above method to prepare the preformed core layer is conducive to achieving firm bonding between different fibers in the core layer, and has a promoting effect on extending the service life of the bamboo charcoal fiber composite material.

[0032] In summary, this application at least includes the following beneficial technical effects:

[0033] (1) The surface layer of the present application is made of 3D-5D low-melting point fibers, 4D-8D bamboo charcoal fibers, and 10D-20D bamboo charcoal fibers in a specific proportion, and the core layer is made of 3D-5D low-melting point fibers, 6D-8D three-dimensional hollow fibers, and 10D-20D three-dimensional hollow fibers in a specific proportion, so as to obtain a bamboo charcoal composite material that is soft, wear-resistant, breathable, has high support strength, and good resilience.

[0034] (2) In the present application, the 3D-5D low melting point fiber contains a hydroxyl group, while the 4D-8D bamboo charcoal fiber, 10D-20D bamboo charcoal fiber, 6D-8D three-dimensional hollow fiber, and 10D-20D three-dimensional hollow fiber contain isocyanate groups after being modified with isocyanate-terminated polyurethane. In the subsequent composite heat baking process, the surface layer and the core layer can be firmly bonded, and the bonding points of the surface layer and the bonding points of the core layer can also be firmly bonded, which has a further enhancing effect on improving the resilience and supporting strength of the bamboo charcoal fiber composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic structural diagram of a bamboo charcoal fiber composite material according to an embodiment of the present application.

[0036] Description of reference numerals:

[0037] 1. Surface layer; 2. Core layer. DETAILED DESCRIPTION

[0038] The present application is further described below in conjunction with specific experiments.

[0039] Example

[0040] [Example 1]

[0041] A bamboo charcoal fiber composite material, referring to Figure 1 The bamboo charcoal fiber composite material includes a surface layer 1, a core layer 2 and a surface layer 1 arranged in sequence from bottom to top, the surface layer 1 is made of 35kg 4D low melting point fiber, 8kg 6D bamboo charcoal fiber and 57kg 15D bamboo charcoal fiber, and the core layer 2 is made of 30kg 4D low melting point fiber, 32kg 7D three-dimensional hollow fiber and 38kg 15D three-dimensional hollow fiber. In this embodiment, the 4D low melting point fiber is specifically obtained by melt spinning of saturated polyester resin GK-888, the cross section of the 7D three-dimensional hollow fiber is circular, and the cross section of the 15D three-dimensional hollow fiber is also circular.

[0042] In this embodiment, the preparation method of the bamboo charcoal fiber composite material comprises the following steps:

[0043] The 4D low melting point fiber, 6D bamboo charcoal fiber and 15D bamboo charcoal fiber are uniformly mixed according to the ratio.

[0044] The first mixed material is sequentially opened, combed and laid to obtain a preformed surface layer, wherein the weight of the preformed surface layer is 25 g / m 2 ;

[0045] The 4D low melting point fiber, the 7D three-dimensional hollow fiber and the 15D three-dimensional hollow fiber are uniformly mixed according to a ratio to obtain a second mixed material, and the second mixed material is opened, combed and laid to form a web at one time to obtain a preformed core layer, and the weight of the preformed core layer is 18g / m 2 ;

[0046] A layer of the preformed surface layer is laid flat on the upper and lower surfaces of the preformed core layer, and the positioning is completed.

[0047] After the product is formed, it is heat-dried at 135° C. and then cooled and shaped to obtain a bamboo charcoal fiber composite material.

[0048] [Example 2]

[0049] A bamboo charcoal fiber composite material, referring to Figure 1 The bamboo charcoal fiber composite material includes a surface layer 1, a core layer 2 and a surface layer 1 arranged in sequence from bottom to top, the surface layer 1 is made of 45kg 4D low melting point fiber, 12kg 6D bamboo charcoal fiber and 43kg 15D bamboo charcoal fiber, and the core layer 2 is made of 40kg 4D low melting point fiber, 38kg 7D three-dimensional hollow fiber and 22kg 15D three-dimensional hollow fiber. In this embodiment, the 4D low melting point fiber is specifically obtained by melt spinning of saturated polyester resin GK-888, the cross section of the 7D three-dimensional hollow fiber is circular, and the cross section of the 15D three-dimensional hollow fiber is also circular.

[0050] In this embodiment, the preparation method of the bamboo charcoal fiber composite material comprises the following steps:

[0051] 4D low melting point fiber, 6D bamboo charcoal fiber and 15D bamboo charcoal fiber are uniformly mixed according to a ratio to obtain a first mixed material, and the first mixed material is sequentially loosened, combed and laid to form a preformed surface layer, and the gram weight of the preformed surface layer is 30g / m 2 ;

[0052] The 4D low melting point fiber, the 7D three-dimensional hollow fiber and the 15D three-dimensional hollow fiber are uniformly mixed according to a ratio to obtain a second mixed material, and the second mixed material is opened, combed and laid to form a web at one time to obtain a preformed core layer, and the weight of the preformed core layer is 22g / m 2 ;

[0053] A layer of the preformed surface layer is laid flat on the upper and lower surfaces of the preformed core layer respectively. After positioning, the preformed surface layer is baked at 110° C. and then cooled to be shaped to obtain a bamboo charcoal fiber composite material.

[0054] [Example 3]

[0055] A bamboo charcoal fiber composite material, which is different from [Example 1] in that:

[0056] In this embodiment, the 6D bamboo charcoal fiber in the preformed surface layer is replaced by an equal amount of 6D bamboo charcoal fiber modified by isocyanate-terminated polyurethane, and the 15D bamboo charcoal fiber is replaced by an equal amount of 15D bamboo charcoal fiber modified by isocyanate-terminated polyurethane. The 7D three-dimensional hollow fiber in the preformed core layer is replaced by an equal amount of 7D three-dimensional hollow fiber modified by isocyanate-terminated polyurethane, and the 15D three-dimensional hollow fiber is replaced by an equal amount of 15D three-dimensional hollow fiber modified by isocyanate-terminated polyurethane.

[0057] The isocyanate-terminated polyurethane used in this embodiment is prepared by the following method:

[0058] Heat 0.6 kmol of polycarbonate diol with a molecular weight of 2000 (CAS number 29862-10-0, brand Maidehao, model MDH) to 55°C, then add 1 kmol of diphenylmethane diisocyanate and 0.002 kg of dibutyltin dilaurate, heat to 90°C and react for 2 hours to obtain isocyanate-terminated polyurethane.

[0059] The isocyanate-terminated polyurethane modified 6D bamboo charcoal fiber is obtained by spraying a layer of isocyanate-terminated polyurethane on the surface of the 6D bamboo charcoal fiber and then drying it; the isocyanate-terminated polyurethane modified 15D bamboo charcoal fiber is obtained by spraying a layer of isocyanate-terminated polyurethane on the surface of the 15D bamboo charcoal fiber and then drying it; the isocyanate-terminated polyurethane modified 7D three-dimensional hollow fiber is obtained by spraying a layer of isocyanate-terminated polyurethane on the surface of the 7D three-dimensional hollow fiber and then drying it; the isocyanate-terminated polyurethane modified 15D three-dimensional hollow fiber is obtained by spraying a layer of isocyanate-terminated polyurethane on the surface of the 15D three-dimensional hollow fiber and then drying it.

[0060] [Example 4]

[0061] A bamboo charcoal fiber composite material, which differs from [Example 1] in that: 4D low melting point fiber is specifically obtained by melt spinning of terminal hydroxyl saturated polyester resin HK-7805 (hydroxyl value is 35-45 mgKOH / g, softening point is 102-112°C).

[0062] [Example 5]

[0063] A bamboo charcoal fiber composite material, which differs from [Example 3] in that: 4D low melting point fiber is specifically obtained by melt spinning of terminal hydroxyl saturated polyester resin HK-7805 (hydroxyl value is 35-45 mgKOH / g, softening point is 102-112°C).

[0064] Comparative Example

[0065] [Comparative Example 1]

[0066] A bamboo charcoal fiber composite material, which is different from [Example 1] in that: 15D bamboo charcoal fiber is replaced by an equal amount of 6D bamboo charcoal fiber.

[0067] [Comparative Example 2]

[0068] A bamboo charcoal fiber composite material, which differs from [Example 1] in that 6D bamboo charcoal fiber is replaced by an equal amount of 15D bamboo charcoal fiber.

[0069] [Comparative Example 3]

[0070] A bamboo charcoal fiber composite material, which differs from [Example 1] in that: 15D three-dimensional hollow fibers are replaced by an equal amount of 7D three-dimensional hollow fibers.

[0071] [Comparative Example 4]

[0072] A bamboo charcoal fiber composite material, which differs from [Example 1] in that: 7D three-dimensional hollow fibers are replaced by an equal amount of 15D three-dimensional hollow fibers.

[0073] Performance testing

[0074] Test (1) Abrasion resistance: The test was carried out in accordance with GB / T 21196.2-2007 “Determination of the abrasion resistance of textile fabrics by the Martindale method - Part 2: Determination of specimen damage”. The average number of frictions when the specimen was damaged was recorded. The greater the average number of frictions, the better the abrasion resistance.

[0075] Test (2) Softness: The test was conducted in accordance with HG / T 3053-1999 “Determination of Softness of Rubber or Plastic Coated Fabrics - Flat Ring Method”. The maximum height of the ring formed by the bamboo charcoal fiber composite material was used to characterize the softness of the bamboo charcoal fiber composite material. The lower the height of the ring, the greater the softness of the bamboo charcoal fiber composite material.

[0076] Test (3) Support strength: Take a bamboo charcoal fiber composite material sample with a thickness of 25 cm, compress it along the thickness direction of the sample at a constant speed for 50 mm, then stop compressing, and record the pressure corresponding to the specified deformation point to evaluate the support strength of the bamboo charcoal fiber composite material. The greater the pressure, the greater the support strength of the bamboo charcoal fiber composite material.

[0077] Test (4) Resilience: Take a bamboo charcoal fiber composite material sample with a thickness of 25 cm, compress it along the thickness direction of the sample at a constant speed for 50 mm, then stop compressing, keep the compression state for 1440 hours, then remove the presser foot, test the thickness difference of the sample before and after compression, and calculate the height recovery rate of the sample, where height recovery rate = [h0-(h0-h1)] / h0*100%, where h0 is the height of the sample before compression and h1 is the height of the sample after compression. The greater the height recovery rate of the sample, the better the resilience of the bamboo charcoal fiber composite material.

[0078] Test (5) Air permeability: Tested in accordance with JIS L 1096-2019.

[0079] Table 1

[0080]

[0081] Combining Example 1 with Comparative Examples 1-2 and the data in Table 1, it can be seen that the use of bamboo charcoal fibers of two specifications, 4D-8D and 10D-20D, in the surface layer is conducive to obtaining a bamboo charcoal fiber composite material having wear resistance, softness, high air permeability, high support and excellent resilience.

[0082] Combining Example 1 with Comparative Examples 3-4 and the data in Table 1, it can be seen that the use of three-dimensional hollow fibers of two specifications of 6D-8D and 10D-20D in the core layer is conducive to obtaining a bamboo charcoal fiber composite material with wear resistance, softness, high air permeability, high support and excellent resilience.

[0083] Combining Example 1 with Examples 3-5 and the data in Table 1, it can be seen that the 3D-5D low-melting point fiber contains a hydroxyl group, and the 4D-8D bamboo charcoal fiber, 10D-20D bamboo charcoal fiber, 6D-8D three-dimensional hollow fiber, and 10D-20D three-dimensional hollow fiber contain an isocyanate group after being modified with isocyanate-terminated polyurethane. In the subsequent composite heat baking process, the surface layer and the core layer can be firmly bonded, and the bonding points of the surface layer and the bonding points of the core layer can also be firmly bonded, which has a further enhancing effect on improving the resilience and supporting strength of the bamboo charcoal fiber composite material.

[0084] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A bamboo charcoal fiber composite material, characterized in that: It comprises a core layer (2) and two surface layers (1) located on the upper and lower surfaces of the core layer (2), wherein the surface layer (1) is made of 35-45wt% 3D-5D low melting point fibers, 8-12wt% 4D-8D bamboo charcoal fibers and the remainder 10D-20D bamboo charcoal fibers, and the core layer (2) is made of 30-40wt% 3D-5D low melting point fibers, 32-38wt% 6D-8D three-dimensional hollow fibers and the remainder 10D-20D three-dimensional hollow fibers; The 3D-5D low melting point fiber is obtained by melt spinning of a hydroxyl-terminated saturated polyester resin, and the 4D-8D bamboo charcoal fiber, 10D-20D bamboo charcoal fiber, 6D-8D three-dimensional hollow fiber, and 10D-20D three-dimensional hollow fiber are respectively modified by isocyanate-terminated polyurethane; The hydroxyl value of the hydroxyl-terminated saturated polyester resin is 35-45 mgKOH / g, the softening point is 102-112°C, and the weight of the core layer is 18-22 g / m 2 The surface layer has a grammage of 25-30 g / m 2 .

2. The bamboo charcoal fiber composite material according to claim 1, characterized in that: The cross section of the 6D-8D three-dimensional hollow fiber is triangular, and the cross section of the 10D-20D three-dimensional hollow fiber is circular or elliptical.

3. The bamboo charcoal fiber composite material according to claim 1, characterized in that: The isocyanate-terminated polyurethane is obtained by reacting a polymeric diol with a diisocyanate in a molar ratio of (0.6-0.8):

1.

4. The bamboo charcoal fiber composite material according to claim 3, characterized in that: The polymer diol is a polyester diol with a molecular weight of 2000-3000.

5. The bamboo charcoal fiber composite material according to claim 3, characterized in that: The diisocyanate is an aromatic diisocyanate.

6. The method for preparing a bamboo charcoal fiber composite material according to any one of claims 1 to 5, characterized in that: The following steps are involved: 3D-5D low melting point fiber, 4D-8D bamboo charcoal fiber and 10D-20D bamboo charcoal fiber are uniformly mixed according to a ratio to obtain a first mixture, and the first mixture is opened, carded and laid to form a preformed surface layer in sequence; 3D-5D low melting point fibers, 6D-8D three-dimensional hollow fibers, and 10D-20D three-dimensional hollow fibers are uniformly mixed according to a ratio to obtain a second mixture, and the second mixture is opened, carded, and laid to form a web at one time to obtain a preformed core layer; A layer of the preformed surface layer is laid flat on the upper and lower surfaces of the preformed core layer respectively. After positioning, the preformed surface layer is baked at 110-135° C. and then cooled to be shaped to obtain a bamboo charcoal fiber composite material.

7. The method for preparing a bamboo charcoal fiber composite material according to claim 6, characterized in that: In the preparation step of the preformed surface layer, a layer of isocyanate-terminated polyurethane is first evenly sprayed on the surface of the 4D-8D bamboo charcoal fiber and the 10D-20D bamboo charcoal fiber. After the isocyanate-terminated polyurethane on the surface of the 4D-8D bamboo charcoal fiber and the 10D-20D bamboo charcoal fiber is dried, it is mixed with 3D-5D low melting point fibers obtained by melt spinning of terminal hydroxyl saturated polyester resin to prepare the preformed surface layer.

8. The method for preparing a bamboo charcoal fiber composite material according to claim 6, characterized in that: In the preparation step of the preformed core layer, a layer of isocyanate-terminated polyurethane is first evenly sprayed on the surface of the 6D-8D three-dimensional hollow fiber and the 10D-20D three-dimensional hollow fiber. After the isocyanate-terminated polyurethane on the surface of the 6D-8D three-dimensional hollow fiber and the 10D-20D three-dimensional hollow fiber is dried, it is mixed with the 3D-5D low-melting point fiber obtained by melt spinning of the terminal hydroxyl saturated polyester resin to prepare the preformed core layer.

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