Glass fiber sound-absorbing cold-proof heat-insulating felt and preparation method thereof

Abstract

The invention relates to the technical field of glass fiber materials, in particular to a glass fiber sound-absorbing cold-proof heat-insulating felt and a preparation method thereof. The preparation method comprises the following steps: S1, preparing a microcapsule template; s2, preparing glass fibers; s3, forming a felt body: S301, mixing the glass fiber and a modified binder according to a mass ratio of 3: 1, adding a dispersing agent and deionized water, and uniformly stirring to obtain glass fiber slurry; and S302, providing a felt body mold, adding a microcapsule template into the felt body mold, further adding the glass fiber slurry, uniformly mixing, and freezing the felt body mold at-20 DEG C for 12-26 hours to obtain the felt body. According to the glass fiber sound-absorbing cold-proof heat-insulating felt and the preparation method, the problems that in the related technology, glass fibers of a glass fiber heat-insulating felt are not tightly connected, the service life is short, and the sound-absorbing heat-insulating effect is poor are solved.

Description

Technical Field

[0001] This application relates to the technical field of glass fiber materials, and particularly relates to a glass fiber sound-absorbing, cold-proof and heat-insulating felt and a preparation method thereof. Background Art

[0002] Glass fiber thermal insulation felt is a felt-like material mainly made of glass fibers. By adjusting the length, diameter, arrangement pattern of glass fibers and their combination with other materials, its sound absorption effect for different frequencies is optimized.

[0003] In the prior art, glass fiber soft felt is usually obtained by heat-treating glass fibers at 800 - 1000°C. It has a loose and porous structure and has a certain sound absorption ability. At the same time, due to the interweaving of fibers inside the felt body, there are certain pores and air. The thermal conductivity of air is relatively low, which can hinder the transfer of heat to a certain extent and play a role in cold-proof and heat-insulating. Heat treatment can make the structure of glass fibers more stable and further improve the heat-insulating effect. However, this process is physical interweaving and a small amount of chemical bond connection. Under the alternating action of high temperature or low temperature for a long time, the connection between fibers may gradually become loose, resulting in low tensile strength and tear strength, and the surface is prone to fuzzing, leading to a low service life of the glass fiber thermal insulation felt and the need for regular replacement, and it cannot achieve an ideal sound absorption and heat insulation effect. Summary of the Invention

[0004] This application provides a glass fiber sound-absorbing, cold-proof and heat-insulating felt and a preparation method thereof to solve the problems in the related art that the connection between glass fibers of the glass fiber thermal insulation felt is not tight enough, the service life is short, and the sound absorption and heat insulation effects are not good.

[0005] In the first aspect, a preparation method of a glass fiber sound-absorbing, cold-proof and heat-insulating felt is provided, which includes the following steps:

[0006] S1. Preparation of microcapsule template:

[0007] S101. Mix melted paraffin and a 2wt% chitosan solution at a mass ratio of 1:(1.5 - 2.5) and stir to obtain a mixed solution, with a stirring speed of 500r / min;

[0008] S102. Under the condition of continuous stirring, add a 0.1g / mL glutaraldehyde solution to the mixed solution and react at 50°C for 2 - 3h to obtain a microcapsule emulsion. The mass-volume ratio of the paraffin to the glutaraldehyde solution is (0.8 - 2):1;

[0009] S103. After mixing the microcapsule emulsion and a polyvinyl alcohol solution at a mass ratio of 1:(2.5 - 3), a microcapsule template is obtained. The concentration of the polyvinyl alcohol solution is 5wt%.

[0010] S2. Preparation of modified glass fiber;

[0011] S3. Felt body forming:

[0012] S301. Mix the modified glass fiber and the modified binder according to a mass ratio of 3:1, add a dispersant and deionized water, and stir evenly to obtain a glass fiber slurry. The mass of the deionized water is 1 - 3 times the sum of the masses of the modified glass fiber and the modified binder, and the dispersant is 0.5 - 2% of the mass of the modified glass fiber;

[0013] S302. Provide a felt body mold, add a microcapsule template to the felt body mold, then continue to add the glass fiber slurry and mix evenly, and place the felt body mold at -20°C for freezing for 12 - 26 h. The mass ratio of the microcapsule template to the glass fiber slurry is 1:(3 - 5);

[0014] S303. Dry the frozen felt body mold at -50°C and 10 Pa for 48 h to obtain a glass fiber sound-absorbing, cold-proof and heat-insulating felt.

[0015] Preferably, the preparation method of the chitosan solution includes:

[0016] Dissolve chitosan in a 1 wt% acetic acid solution to obtain a 2 wt% chitosan solution.

[0017] Preferably, the preparation of the modified glass fiber includes:

[0018] S201. Pretreatment: Heat the glass fiber raw material to 600 - 800°C at a heating rate of 2 - 4°C / min, keep it warm for 2 h, and remove surface impurities;

[0019] S202. Surface treatment: Immerse the pretreated glass fiber in a 3-aminopropyltriethoxysilane solution with a mass concentration of 8% for 0.5 - 1 h, and dry it at 120°C for 30 min to obtain modified glass fiber.

[0020] Preferably, after S201 and before S202, it further includes:

[0021] Immerse the product obtained in S201 in the treatment liquid for 0.5 - 1 h, and then dry it at 80°C for 20 min;

[0022] The treatment liquid includes dibutyl phthalate, phenolic resin and deionized water, and the mass ratio of dibutyl phthalate, phenolic resin to deionized water is 1:(5 - 6):8.

[0023] Preferably, the preparation method of the modified binder includes the following steps:

[0024] Dissolve lignin in absolute ethanol at a mass - to - volume ratio of 1:(3 - 5), stir for 20 min at 50°C, add phenolic resin to the ethanol solution of lignin, and continue to stir for 30 min at 50°C to obtain a modified binder.

[0025] The mass ratio of the lignin to the phenolic resin is (0.15 - 0.25):1.

[0026] Preferably, the dispersant is one of sodium polyacrylate and sodium hexametaphosphate.

[0027] In a second aspect, a glass fiber sound - absorbing, cold - proof and heat - insulating felt is provided, which is prepared by the preparation method of the glass fiber sound - absorbing, cold - proof and heat - insulating felt described in any one of the above.

[0028] The beneficial effects brought by the technical solutions provided in this application include:

[0029] This application provides a glass fiber sound - absorbing, cold - proof and heat - insulating felt and a preparation method. Micro - capsules are dispersed in the network structure formed by the interweaving of glass fibers and are connected by a modified binder to form a continuous bonding phase, enhancing the connection strength of the felt body. The micro - capsules help improve the internal interface and pore structure of the material, enabling more scattering and absorption of sound waves during propagation. The glass fiber itself has a low thermal conductivity, and the micro - capsules use paraffin as the core material, which has a certain phase - change energy storage capacity and can absorb or release heat when the temperature changes, thereby enhancing the cold - proof and heat - insulating functions of the felt body. Finally, the felt body is formed at low temperature. Water freezes at low temperature to form ice crystals, and the glass fibers and micro - capsule templates are distributed in the gaps between the ice crystals, thus forming a felt body prototype with a pore structure, which is beneficial for sound absorption and heat insulation. Therefore, it can solve the problems in the related art that the connection between glass fibers in the glass fiber thermal insulation felt is not tight enough, the service life is short, and the sound - absorption and heat - insulation effects are not good. At the same time, the use of glass fibers in the present invention makes the material more cost - effective and the cost lower. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0031] Figure 1 It is a schematic flow chart of the preparation method of the glass fiber sound - absorbing, cold - proof and heat - insulating felt provided in this application. Detailed Embodiments

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Apparently, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the scope of protection of this application.

[0033] See Figure 1 As shown, this application provides a glass fiber sound-absorbing, cold-proof, and heat-insulating felt and a preparation method thereof, which can solve the problems in the related art that the connection between glass fibers in the glass fiber heat-insulating felt is not tight enough, the service life is short, and the sound-absorbing and heat-insulating effects are not good.

[0034] The preparation method of the glass fiber sound-absorbing, cold-proof, and heat-insulating felt includes the following steps:

[0035] S1. Preparation of microcapsule template:

[0036] S101. Stir and mix the melted paraffin and a 2wt% chitosan solution in a mass ratio of 1:(1.5 - 2.5) to obtain a mixed solution, and the stirring speed is 500r / min;

[0037] S102. Under the condition of continuous stirring, add a 0.1g / mL glutaraldehyde solution to the mixed solution, react at 50°C for 2 - 3h to obtain a microcapsule emulsion, and the mass-to-volume ratio of paraffin to the glutaraldehyde solution is (0.8 - 2):1;

[0038] S103. After mixing the microcapsule emulsion and a polyvinyl alcohol solution in a mass ratio of 1:(2.5 - 3), a microcapsule template is obtained, and the concentration of the polyvinyl alcohol solution is 5wt%.

[0039] Microcapsules help improve the internal interface and pore structure of the material, enabling more scattering and absorption of sound waves during propagation. Paraffin, as the core material, has a phase change energy storage function and can absorb or release heat when the temperature changes, playing a good role in cold-proof and heat-insulating aspects. Combined with glass fibers with heat-insulating properties, it can further reduce the thermal conductivity of the felt.

[0040] S2. Preparation of modified glass fibers:

[0041] S201. Pretreatment: Heat the glass fiber raw material at a heating rate of 2 - 4°C / min to 600 - 800°C, hold for 2h to remove surface impurities;

[0042] S202. Surface treatment: Immerse the pretreated glass fibers in an 8% mass concentration of 3-aminopropyltriethoxysilane solution for 0.5 - 1h, and dry at 120°C for 30min to obtain modified glass fibers.

[0043] In some embodiments, after S201 and before S202, it further includes:

[0044] The product obtained in S201 is immersed in the treatment liquid for 0.5 - 1 h and then dried at 80 °C for 20 min;

[0045] The treatment liquid includes dibutyl phthalate, phenolic resin and deionized water, and the mass ratio of dibutyl phthalate, phenolic resin to deionized water is 1:(5 - 6):8.

[0046] S3. Felt body forming:

[0047] S301. Mix glass fibers and the modified binder in a mass ratio of 3:1, add a dispersant and deionized water, and stir evenly to obtain a glass fiber slurry. The mass of deionized water is 1 - 3 times the sum of the masses of glass fibers and the modified binder, and the dispersant is 0.5 - 2% of the mass of glass fibers;

[0048] In some embodiments, the dispersant is one of sodium polyacrylate and sodium hexametaphosphate.

[0049] S302. Provide a felt body mold, add a microcapsule template into the felt body mold, then continue to add the glass fiber slurry and mix evenly, and place the felt body mold at -20 °C for freezing for 12 - 26 h. The mass ratio of the microcapsule template to the glass fiber slurry is 1:(3 - 5);

[0050] S303. Dry the frozen felt body mold at -50 °C and 10 Pa for 48 h to obtain a glass fiber sound - absorbing, cold - proof and heat - insulating felt.

[0051] After drying and curing, the modified binder forms a bonding phase inside the glass fibers and the microcapsules, enabling the glass fibers to better withstand external forces in the felt body and avoiding breakage.

[0052] In some embodiments, the preparation method of the modified binder includes: dissolving lignin in absolute ethanol at a mass - to - volume ratio of 1:(3 - 5), stirring at 50 °C for 20 min, adding phenolic resin to the ethanol solution of lignin, and continuing to stir at 50 °C for 30 min to obtain the modified binder;

[0053] The mass ratio of lignin to phenolic resin is (0.15 - 0.25):1.

[0054] In the following examples and comparative examples, the length of the asphalt fibers used is 3 - 4 mm and the diameter is 10 μm.

[0055] Example 1

[0056] The preparation method of the glass fiber sound - absorbing, cold - proof and heat - insulating felt in this example includes:

[0057] S1. Preparation of microcapsule template:

[0058] S101. Dissolve 10 g of chitosan in 500 g of acetic acid solution with a concentration of 1 wt%, to obtain a 2 wt% chitosan solution;

[0059] Weigh 5 g of paraffin wax, heat it until it melts, and slowly add it to the chitosan solution, and stir and mix at a speed of 500 r / min to obtain a mixed solution;

[0060] S102. Under the condition of continuous stirring, add 5 mL of glutaraldehyde solution with a concentration of 0.1 g / mL to the mixed solution, and react at 50 °C for 2 h to obtain a microcapsule emulsion;

[0061] S103. Mix 100 g of the microcapsule emulsion obtained in S102 with 300 g of polyvinyl alcohol solution with a concentration of 5 wt% to obtain a microcapsule template.

[0062] S2. Preparation of modified glass fiber:

[0063] S201. Pretreatment: Heat 500 g of glass fiber raw material to 600 °C at a heating rate of 2 °C / min, and keep it warm for 2 h to remove surface impurities;

[0064] S202. Surface treatment: Immerse the pretreated glass fiber in a 3-aminopropyltriethoxysilane solution with a mass concentration of 8% for 0.5 h, and dry it at 120 °C for 30 min to obtain modified glass fiber.

[0065] S3. Felt forming:

[0066] S301. Stir 300 g of modified glass fiber, 100 g of modified binder, 1.5 g of sodium polyacrylate and 800 g of deionized water evenly to obtain a glass fiber slurry;

[0067] S302. Provide a felt mold, add 100 g of microcapsule template to the felt mold, then pour 300 g of glass fiber slurry into the felt mold and ultrasonically mix it, and then place the felt mold at -20 °C for 12 h to freeze to obtain a felt;

[0068] S303. Dry the frozen felt mold at -50 °C and 10 Pa for 48 h to obtain a glass fiber sound-absorbing, cold-proof and heat-insulating felt.

[0069] The preparation method of the modified binder includes the following steps:

[0070] Dissolve 20 g of lignin in 60 mL of absolute ethanol, stir at 50 °C for 20 min, add 80 g of phenolic resin to the ethanol solution of lignin, and continue to stir at 50 °C for 30 min to obtain a modified binder.

[0071] Example 2

[0072] The difference from Example 1 is that in S101, the addition amount of paraffin is 4 g, and in S103, the addition amount of polyvinyl alcohol solution is 250 g;

[0073] In S301, the addition amount of sodium polyacrylate is 6 g, the addition amount of deionized water is 1200 g, and in S302, the freezing time is 26 h.

[0074] Example 3

[0075] The preparation method of the glass fiber sound-absorbing and cold-proof heat-insulating felt in this example includes:

[0076] S1. Preparation of microcapsule template:

[0077] S101. Dissolve 6 g of chitosan in 300 g of acetic acid solution with a concentration of 1 wt%, to obtain a 2 wt% chitosan solution;

[0078] Weigh 4 g of paraffin, heat it until it melts, and slowly add it to the chitosan solution, stir and mix at a speed of 500 r / min to obtain a mixed solution;

[0079] S102. Under the condition of continuous stirring, add 4 mL of glutaraldehyde solution with a concentration of 0.1 g / mL to the mixed solution, react at 50 °C for 2 h to obtain a microcapsule emulsion;

[0080] S103. Mix 100 g of the microcapsule emulsion obtained in S102 with 275 g of polyvinyl alcohol solution with a concentration of 5 wt% to obtain a microcapsule template.

[0081] S2. Preparation of modified glass fiber:

[0082] S201. Pretreatment: Heat the glass fiber raw material to 800 °C at a heating rate of 4 °C / min, keep it warm for 2 h to remove surface impurities;

[0083] Immerse the product obtained in S201 in the treatment solution for 0.5 - 1 h, and then dry it at 80 °C for 20 min;

[0084] In this example, the treatment solution includes 100 g of dibutyl phthalate, 500 g of phenolic resin and 800 g of deionized water.

[0085] S202. Surface treatment: Immerse the pretreated glass fiber in a 3-aminopropyltriethoxysilane solution with a mass concentration of 8% for 1 h, and dry it at 120 °C for 30 min to obtain modified glass fiber.

[0086] S3. Felt body forming:

[0087] S301. Stir 300 g of modified glass fiber, 100 g of modified binder, 3 g of sodium hexametaphosphate, and 400 g of deionized water evenly to obtain glass fiber slurry;

[0088] S302. Provide a felt body mold, add 100 g of microcapsule template to the felt body mold, then pour 400 g of glass fiber slurry into the felt body mold and mix it ultrasonically, and place the felt body mold at -20 °C for freezing for 24 h to obtain a felt body;

[0089] S303. Dry the frozen felt body mold at -50 °C and 10 Pa for 48 h to obtain a glass fiber sound-absorbing, cold-proof and heat-insulating felt.

[0090] The preparation method of the modified binder includes the following steps:

[0091] Dissolve 20 g of lignin in 80 mL of absolute ethanol, stir at 50 °C for 20 min, add 100 g of phenolic resin to the ethanol solution of lignin, and continue to stir at 50 °C for 30 min to obtain a modified binder.

[0092] Example 4

[0093] The difference from Example 3 is that: in S102, the addition amount of glutaraldehyde solution is 2 mL; and in S201, the treatment solution includes 100 g of dibutyl phthalate, 600 g of phenolic resin, and 800 g of deionized water;

[0094] And in S302, add 100 g of microcapsule template and 500 g of glass fiber slurry to the felt body mold.

[0095] Example 5

[0096] The difference from Example 3 is that: in S201, the heating rate is 4 °C / min, and in the modified binder of S302, the addition amount of ethanol is 100 mL, and the addition amount of phenolic resin is 134 g.

[0097] Comparative Example 1

[0098] The difference between this comparative example and Example 1 is that S2 is not carried out. It includes the following steps:

[0099] (1) Microcapsule template preparation:

[0100] S101. Dissolve 10 g of chitosan in 500 g of acetic acid solution with a concentration of 1 wt%, to obtain a chitosan solution with a concentration of 2 wt%.

[0101] Weigh 5 g of paraffin, heat it until it melts, and slowly add it to the chitosan solution, and stir and mix at a speed of 500 r / min to obtain a mixed solution.

[0102] S102. Under the condition of continuous stirring, add 5 mL of glutaraldehyde solution with a concentration of 0.1 g / mL to the mixed solution, and react at 50 °C for 2 h to obtain a microcapsule emulsion.

[0103] S103. Mix 100 g of the microcapsule emulsion obtained in S102 with 300 g of a polyvinyl alcohol solution with a concentration of 5 wt% to obtain a microcapsule template.

[0104] (2) Felt body forming:

[0105] S301. Stir 300 g of glass fiber, 100 g of modified binder (the preparation method is the same as that in Example 1), 1.5 g of sodium polyacrylate, and 800 g of deionized water evenly to obtain a glass fiber slurry.

[0106] S302. Provide a felt body mold, add 400 g of the glass fiber slurry to the felt body mold, after ultrasonic treatment, place the felt body mold at -20 °C and freeze for 12 h to obtain a felt body.

[0107] S303. Dry the frozen felt body mold at -50 °C and 10 Pa for 48 h to obtain a glass fiber sound-absorbing, cold-proof and heat-insulating felt.

[0108] Comparative Example 2

[0109] The difference between this comparative example and Example 1 is that S1 is not carried out and the modified binder is not used. It includes the following steps:

[0110] (1) Preparation of modified glass fiber:

[0111] Pretreatment: Heat 500 g of glass fiber raw material to 600 °C at a heating rate of 2 °C / min, and keep it warm for 2 h to remove surface impurities.

[0112] Surface treatment: Immerse the pretreated glass fiber in a 3-aminopropyltriethoxysilane solution with a mass concentration of 8% for 0.5 h, and dry it at 120 °C for 30 min to obtain modified glass fiber.

[0113] (2) Felt body forming:

[0114] S301. Stir 300 g of modified glass fiber, 100 g of phenolic resin, 1.5 g of sodium polyacrylate, and 800 g of deionized water evenly to obtain a glass fiber slurry.

[0115] S302. Provide a felt mold, add 400 g of glass fiber slurry to the felt mold. After ultrasonic treatment, place the felt mold at -20°C and freeze it for 12 h to obtain a felt body.

[0116] S303. Dry the frozen felt mold at -50°C and 10 Pa for 48 h to obtain a glass fiber sound-absorbing, cold-proof and heat-insulating felt.

[0117] Comparative Example 3

[0118] The difference between this comparative example and Example 3 is that S1 is not carried out. It includes the following steps:

[0119] (1) Preparation of modified glass fiber:

[0120] Pretreatment: Heat 500 g of glass fiber raw material to 600°C at a heating rate of 2°C / min, hold for 2 h to remove surface impurities.

[0121] Immerse the product in the treatment liquid for 0.5 - 1 h, and then dry it at 80°C for 20 min.

[0122] The treatment liquid includes 100 g of dibutyl phthalate, 500 g of phenolic resin and 800 g of deionized water.

[0123] Surface treatment: Immerse the pretreated glass fiber in a 3-aminopropyltriethoxysilane solution with a mass concentration of 8% for 0.5 h, and then dry it at 120°C for 30 min to obtain modified glass fiber.

[0124] (2) Felt body forming:

[0125] Mix 300 g of modified glass fiber, 100 g of modified binder (prepared in the same way as in Example 3), 3 g of sodium hexametaphosphate and 400 g of deionized water evenly to obtain a glass fiber slurry.

[0126] Provide a felt mold, add 500 g of glass fiber slurry to the felt mold. After ultrasonic treatment, place the felt mold at -20°C and freeze it for 24 h to obtain a felt body.

[0127] Dry the frozen felt mold at -50°C and 10 Pa for 48 h to obtain a glass fiber sound-absorbing, cold-proof and heat-insulating felt.

[0128] According to GB / T 18696.1 - 2004 "Measurement of Sound Absorption Coefficient and Acoustic Impedance in Acoustic Impedance Tube - Part 1: Standing Wave Ratio Method", measure the sound absorption coefficients of the glass fiber sound-absorbing, cold-proof and heat-insulating felts of Examples 1 - 5 and Comparative Examples 1 - 3 at 500 Hz, 800 Hz and 1200 Hz respectively.

[0129] The tensile strength of Examples 1-5 and Comparative Examples 1-3 was tested according to GB / T 10296-2008 "Test Method for Tensile Properties of Thermal Insulation Materials".

[0130] According to GB / T 10297-2015 "Determination of Thermal Conductivity of Non-Metallic Solid Materials - Hot Wire Method", the thermal conductivity of Examples 1-5 and Comparative Examples 1-3 was tested at 25°C.

[0131] The performance parameters of Examples 1-5 and Comparative Examples 1-3 are shown in Table 1.

[0132] Table 1

[0133]

[0134] Referring to Table 1, compared with other examples, Example 2 has a higher sound absorption coefficient at low frequencies and a lower sound absorption coefficient at high frequencies, indicating that it has better absorption of low-frequency sounds but poor absorption of high frequencies; Examples 3-5 have relatively high tensile strength, indicating that a bonding phase has formed inside the asphalt fibers impregnated with the treatment liquid, improving the connection strength between the subsequent glass fibers and the microcapsules, and thus enhancing the mechanical properties of the felt body. Comparative Example 1 omits the step of modifying the glass fibers in step S2 compared with Example 1, Comparative Example 2 does not perform step S1 and does not use the modified binder compared with Example 1, and Comparative Example 3 does not perform step S1. The data in Table 1 show that the present invention has a strong improvement in terms of sound absorption coefficient, tensile strength, and thermal conductivity through the action of the microcapsule template and the modified glass fibers. After the microcapsule template and the glass fibers are mixed and freeze-dried, the ice template sublimes and is removed, forming a porous structure, which improves the pore structure inside the felt body. At the same time, the paraffin in the microcapsule template, as the core material, has a good phase change energy storage function, reducing the thermal conductivity of the felt body.

[0135] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for preparing a glass fiber sound-absorbing, cold-proof and heat-insulating felt, characterized in that: It includes the following steps: S1. Preparation of microcapsule template: S101, stirring and mixing melted paraffin and 2 wt % chitosan solution in a mass ratio of 1:(1.5-2.5) to obtain a mixed solution at a stirring speed of 500 r / min; S102, adding 0.1 g / mL glutaraldehyde solution to the mixed solution under continuous stirring, reacting at 50° C. for 2 to 3 hours to obtain a microcapsule emulsion, wherein the mass volume ratio of the paraffin wax to the glutaraldehyde solution is (0.8 to 2):1; S103, mixing the microcapsule emulsion and the polyvinyl alcohol solution in a mass ratio of 1:(2.5-3) to obtain a microcapsule template, wherein the concentration of the polyvinyl alcohol solution is 5wt%; S2, preparation of modified glass fiber; S3, Felt body forming: S301, mixing the modified glass fiber and the modified binder in a mass ratio of 3:1, adding a dispersant and deionized water, and stirring evenly to obtain a glass fiber slurry, wherein the mass of the deionized water is 1 to 3 times the sum of the mass of the modified glass fiber and the modified binder, and the dispersant is 0.5 to 2% of the mass of the modified glass fiber; S302, providing a felt mold, adding a microcapsule template to the felt mold, and then adding glass fiber slurry and mixing evenly, placing the felt mold in a -20°C environment and freezing for 12 to 26 hours to obtain a felt, wherein the mass ratio of the microcapsule template to the glass fiber slurry is 1:(3 to 5); S303, drying the frozen felt body mold at -50°C and 10Pa for 48 hours to obtain a glass fiber sound-absorbing, cold-proof and heat-insulating felt.

2. The method for preparing the glass fiber sound-absorbing, cold-proof and heat-insulating felt according to claim 1, characterized in that: The preparation method of the chitosan solution comprises: Chitosan was dissolved in 1 wt % acetic acid solution to obtain a 2 wt % chitosan solution.

3. The method for preparing the glass fiber sound-absorbing, cold-proof and heat-insulating felt according to claim 1, characterized in that: The modified glass fiber preparation comprises: S201, pretreatment: heating the glass fiber raw material to 600-800°C at a heating rate of 2-4°C / min, keeping the temperature for 2 hours, and removing surface impurities; S202, surface treatment: immersing the pretreated glass fiber in a 3-aminopropyltriethoxysilane solution with a mass concentration of 8% for 0.5 to 1 hour, and drying at 120° C. for 30 minutes to obtain a modified glass fiber.

4. The method for preparing the glass fiber sound-absorbing, cold-proof and heat-insulating felt according to claim 3, characterized in that: After S201 and before S202, it also includes: The product obtained in S201 was immersed in the treatment solution for 0.5 to 1 h, and then dried at 80°C for 20 min; The treatment liquid comprises dibutyl phthalate, phenolic resin and deionized water, and the mass ratio of the dibutyl phthalate, phenolic resin and deionized water is 1:(5-6):

8.

5. The method for preparing the glass fiber sound-absorbing cold-proof heat-insulating felt according to claim 1, characterized in that: The preparation method of the modified binder comprises the following steps: Dissolve lignin in anhydrous ethanol at a mass volume ratio of 1:(3-5), stir at 50°C for 20 minutes, add phenolic resin to the ethanol solution of lignin, and continue to stir at 50°C for 30 minutes to obtain a modified binder; The mass ratio of the lignin to the phenolic resin is (0.15-0.25):

1.

6. The method for preparing the glass fiber sound-absorbing cold-proof heat-insulating felt according to claim 1, characterized in that: The dispersant is one of sodium polyacrylate and sodium hexametaphosphate.

7. A glass fiber sound-absorbing, cold-proof and heat-insulating felt, which is prepared by the preparation method of the glass fiber sound-absorbing, cold-proof and heat-insulating felt according to any one of claims 1 to 6.

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