Thermal-insulation and temperature-keeping aerogel fiber and method for manufacturing the fiber

Abstract

To provide a thermal-insulation and temperature-keeping aerogel fiber that can avoid influence to fiber performance caused by breaking of aerogel in the fiber, and can improve moisture absorbability and dyeability of aerogel fiber, and a method for manufacturing the fiber.SOLUTION: An aerogel fiber is a two-layered structure in which an inner layer includes SiO2 aerogel and cellulose aerogel, and an outer layer is a protein membrane. Plant powder and silicon source auxiliary additive are added to a fiber raw material and mixed, the mixture is allowed to pass through spinning holes to manufacture an initial fiber, the plant powder and the silicon source auxiliary additive are distributed into the initial fiber, and furthermore, immersed into dispersion liquid, cellulose aerogel and SiO2 aerogel are uniformly generated inside the initial fiber after passing through a step such as extremely low temperature treatment to obtain an aerogel composite fiber, the aerogel composite fiber is immersed into fruit acid auxiliary additive containing protein to allow protein and fruit acid to cause cross-linking reaction, a single layer of a protein membrane is formed on a surface of the aerogel composite fiber, and a two-layered structure in which the inner layer is an aerogel composite fiber and the outer layer is a protein membrane is obtained.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention belongs to the field of fiber technology, and specifically relates to heat-insulating and heat-preserving aerogel fibers and a manufacturing method thereof.

Background Art

[0002] An aerogel is a porous material derived from a gel, and has characteristics such as a high specific surface area, a high porosity, a low density, and a low thermal conductivity, and has great application prospects in fields such as biology, medicine, and architecture. With intensive research, aerogels are gradually applied to the field of fiber spinning. By adding aerogels to fibers and fabrics, a lightweight heat-preserving effect can be imparted to the fibers. In the research on aerogels, SiO2 aerogel is the mainstream direction of research in the spinning field. Although the application range of SiO2 aerogel is wide, its drawback is that SiO2 aerogel is brittle and fragments and powders are likely to occur in the actual production process.

[0003] The fabric of SiO2 aerogel has low drawability and plasticity. Taking a non-woven sandwich material as an example, a non-woven sandwich material refers to a filled fabric with a three-layer structure in which the sandwich layer is a non-woven fabric substrate and the core layer is an aerogel. The non-woven fabric substrate is usually limited to polyester or polypropylene. Although the non-woven sandwich material is heat-insulated, it is rarely used for fabric weaving and cannot be dyed for the substrate. In addition, the non-woven sandwich material has low surface moisture and is prone to generating static electricity, which can damage the human body. For example, it can irritate the human skin, reduce the skin moisture, and cause symptoms such as skin dryness, flaking, and itching. The fabric made from the non-woven sandwich material has a high gram weight and a heavy thickness, reaching 0.3 cm or more for a single layer, and has low wearing comfort, which limits its development in the fabric field.

[0004] To apply more SiO2 aerogels to the textile industry, researchers have focused on aerogel fibers. There are many commercially available fibers containing SiO2 aerogels, which are produced by directly blending SiO2 aerogel powder with polymer chips or spinning dope. For example, when the patent number is "CN202211310230.9" and the title is "Graphene Aerogel Fiber and Its Manufacturing Method", polyester chips are crushed, and then the powder is mixed with graphene material, aerogel glass bead material, and modifier, and then a composite masterbatch is obtained by extrusion granulation and melt spinning. However, SiO2 aerogels are highly brittle and their porous structures are easily damaged. During the spinning process, the voids in the SiO2 aerogels collapse, resulting in non-uniform distribution of the porous structures in the fibers and affecting the performance of the fibers.

Summary of the Invention

Problems to be Solved by the Invention

[0005] To solve the problems existing in the prior art, the present invention provides a heat-insulating and heat-preserving aerogel fiber and its manufacturing method, which avoid the influence on fiber performance caused by the crushing of aerogels in the fibers and improve the hygroscopicity and dyeability of the aerogel fibers.

Means for Solving the Problems

[0006] To solve the above technical problems, the present invention adopts the following technical means. The first object of the present invention is to provide a heat-insulating and heat-preserving aerogel fiber with a two-layer structure, in which the inner layer is an aerogel composite fiber containing SiO2 aerogel and cellulose aerogel, and the outer layer is a protein film. The second object of the present invention is to provide a manufacturing method of a heat-insulating and heat-preserving aerogel fiber, which includes the following steps.

[0007] S1. Add plant powder and silicon source assistant to the fiber raw materials and stir for 30 - 40 minutes to obtain mixed fiber raw materials. S2. After extruding the mixed fiber raw materials from the spinning holes, stretch them to obtain initial fibers.

[0008] In S3, the initial fibers are immersed in the dispersion liquid, left standing, subjected to cryogenic treatment, eluted to obtain aerogel composite fibers, and further immersed in a fruit acid auxiliary agent containing protein for reaction. After washing with water, a treatment method of preliminary drying and re-drying is adopted to manufacture heat-insulating and heat-preserving aerogel fibers having a two-layer structure.

[0009] Preferably, the plant powder in S1 is powder of one or more of flax, coniferous tree, sugarcane, cotton, seaweed, shiitake mushroom, and corn, and the particle size of the powder is 300 nm - 2 μm. Preferably, the silicon source auxiliary agent in S1 is one or more of sodium silicate, silicon tetrachloride, methyl orthosilicate, and ethyl orthosilicate.

[0010] Preferably, the fibers of the fiber raw material in S1 are one or more of polyester, regenerated cellulose fiber, polyurethane, acrylic, nylon, and acrylic.

[0011] Preferably, the stirring speed is 500 - 800 r / min. Preferably, the addition amount of the plant powder in S1 is 0.3 - 10 wt% of the active ingredient of the fiber raw material.

[0012] Preferably, the addition amount of the silicon source auxiliary agent in S1 is 1 - 5 wt% of the active ingredient of the fiber raw material. The active ingredient of the cellulose fiber raw material refers to alpha cellulose in the cellulose fiber spinning dope.

[0013] Preferably, the solute of the dispersion liquid in S3 is one or more of sodium bicarbonate, ammonia monohydrate, dimethylamine, triethylamine, aniline, and pyridine, and the solvent is water.

[0014] Preferably, the concentration of the dispersion liquid in S3 is 0.5 - 2 wt%. Preferably, the standing time in S3 is 3 - 5 min. Preferably, the temperature of the cryogenic treatment in S3 is -196°C, and the time is 1 - 10 s.

[0015] Preferably, an organic solvent is used for elution in S3, and the organic solvent is one or more of methanol, ethanol, isopropanol, and acetone.

[0016] Preferably, the fruit acid auxiliary agent containing protein in S3 contains protein, fruit acid, and water. The protein is one or more of soybean-derived protein, wheat protein, pea protein, corn protein, and keratin protein. The fruit acid is one or more of citric acid, malic acid, tannic acid, and gallic acid. Furthermore, in the fruit acid auxiliary agent containing protein, the protein accounts for 10 - 15 wt%, the fruit acid accounts for 2 - 4 wt%, and the rest is water.

[0017] Preferably, the aerogel composite fiber in S3 is immersed in the fruit acid auxiliary agent containing protein for reaction. The reaction time is 4 - 5 h, and the reaction temperature is 30 - 35°C.

[0018] Preferably, the temperature of the preliminary drying in S3 is 60°C - 90°C, and the time is 50 minutes - 60 minutes. Preferably, the drying temperature in S3 is 120 - 150°C, and the time is 90 - 120 min.

Advantages of the Invention

[0019] By adopting the above technical solution, the technical effects achieved by the present invention are as follows.

[0020] 1. The heat-insulating and heat-preserving aerogel fiber produced by the present invention has a fineness of 0.5 - 9 dtex, a density of 0.7 - 1.0 g / cm 3 and a bulk height > 5 cm. After being made into a fabric, the single-layer thickness is less than 0.02 cm, and it is lighter and more comfortable to wear.

[0021] 2. The heat-insulating and heat-preserving aerogel fiber manufactured by the present invention has a thermal conductivity of 0.008 - 0.02 w / m·K (measured according to GB / T 35762-2017). The thermal conductivity of general acrylic fiber is 0.032 w / m·K, the thermal conductivity of general polyester is 0.07 w / m·K, and the thermal conductivity of hollow polyester is 0.04 w / m·K. Therefore, its heat-insulating and heat-preserving performance is better than that of general fibers. The fiber has good hygroscopicity, with a moisture content greater than 2%, excellent quick-drying performance, an evaporation rate greater than 0.2 g / h (measured according to GB / T21655.1-2008), and is lightweight, heat-preserving, moisture-absorbing, and quick-drying.

[0022] 3. The heat-insulating and heat-preserving aerogel fiber manufactured by the present invention has far-infrared heating performance. Among them, the far-infrared emissivity exceeds 0.88, the temperature rise under far-infrared irradiation exceeds 3°C (measured by GB / T 30127-2013), has good dyeing performance, and the dyeing uniformity is above grade 4.

[0023] 4. In the present invention, plant powder and silicon source auxiliary agent are added to the fiber raw material and blended, and then the initial fiber is manufactured through the spinning hole. The plant powder and silicon source auxiliary agent are distributed inside the initial fiber, and then immersed in the dispersion liquid. Through steps such as cryogenic treatment, cellulose aerogel and SiO2 aerogel are uniformly generated inside the initial fiber to obtain aerogel composite fiber. Avoid causing certain damage to the structure of the aerogel when directly blending cellulose aerogel and SiO2 aerogel with the fiber raw material and extruding, and avoid the crushed aerogel structure from affecting the performance of the fiber.

[0024] 5. Immerse the aerogel composite fiber in the fruit acid auxiliary agent containing protein, so that the protein and fruit acid undergo a cross-linking reaction to form a layer of protein film on the surface of the aerogel composite fiber, obtaining a two-layer structure with the inner layer being the aerogel composite fiber and the outer layer being the protein film. The formation of the protein film makes the fiber more skin-friendly, and at the same time improves the hygroscopicity and dyeing effect of the fiber.

[0025] 6. In S3, adopt a treatment method of pre-drying and then drying, so that the protein film further solidifies on the surface of the aerogel composite fiber, and avoid the protein film from shrinking unevenly and rapidly at high temperature to generate bubbles, small wrinkles, etc., which will affect the appearance of the fiber.

Embodiments for Carrying out the Invention

[0026] Hereinafter, the present invention will be further described with reference to specific embodiments. Example 1 S1. Add flax powder and ethyl orthosilicate to polyester chips and stir for 35 min. The stirring speed is 600 r / min to obtain a mixed fiber raw material. S2. Adopt melt spinning. After the mixed fiber raw material melts, it is extruded from the spinning holes and stretched to obtain initial fibers.

[0027] S3. Immerse the initial fibers in a dispersion liquid, stand still, perform cryogenic treatment, and elute to obtain aerogel composite fibers. Then immerse them in a fruit acid auxiliary agent containing protein and react. After washing with water, adopt a treatment method of pre-drying and then re-drying to manufacture heat-insulating and heat-preserving aerogel fibers with a two-layer structure.

[0028] The particle size of the flax powder in S1 is 1 μm. The addition amount of the flax powder in S1 is 5 wt% of the polyester chips. The addition amount of ethyl orthosilicate in S1 is 3 wt% of the polyester chips.

[0029] The process parameters of the melt spinning in S2 are that the temperature in region 1 is 300 °C, the temperature in region 2 is 315 °C, the temperature in region 3 is 310 °C, and the temperature in region 4 is 305 °C.

[0030] The solute of the dispersion liquid in S3 is triethylamine, the solvent is water, and the concentration of the dispersion liquid is 1.5 wt%. The standing time in S3 is 4 min, the temperature of the cryogenic treatment is -196 °C, and the time is 7 s.

[0031] An organic solvent is used for the elution in S3, and the organic solvent is isopropanol. In the fruit acid auxiliary agent containing protein in S3, the soy protein accounts for 12 wt%, the citric acid accounts for 3 wt%, and the rest is water.

[0032] In S3, the aerogel composite fiber is immersed in the fruit acid auxiliary agent containing protein and reacted. The reaction time is 4.5 h and the reaction temperature is 35 °C. The temperature of the preliminary drying in S3 is 70 °C and the time is 55 min. In S3, the drying temperature is 140 °C and the time is 100 min.

[0033] The heat-insulating and heat-preserving aerogel fiber produced in Example 1 has a fineness of 1.5 dtex, a density of 0.76 g / cm 3 , a breaking strength of 4.4 cN / dtex, a bulk height of 5.8 cm, a thermal conductivity of 0.012 w / m·K, a moisture content of 3%, an evaporation rate of 0.25 g / h, a far-infrared emissivity of 0.91, a far-infrared irradiation temperature of 3.6 °C, and a dyeing evenness of grade 4.

[0034] Example 2 S1. Add flax powder and sodium silicate to polyester chips, stir at a stirring speed of 800 r / min for 30 min to obtain a blended fiber raw material. S2. Adopt melt spinning. After the mixed fiber raw material melts, it is extruded from the spinning holes and stretched to obtain initial fibers.

[0035] S3. Immerse the initial fibers in a dispersion liquid, stand still, perform cryogenic treatment, elute to obtain aerogel composite fibers, and further immerse them in a fruit acid auxiliary agent containing protein and react. After washing with water, adopt the treatment methods of preliminary drying and re-drying to manufacture heat-insulating and heat-preserving aerogel fibers with a two-layer structure.

[0036] The particle size of the flax powder in S1 is 2 μm. The addition amount of flax powder in S1 is 0.3 wt% of the polyester chips. The addition amount of ethyl orthosilicate in S1 is 1 wt% of the polyester chips.

[0037] The process parameters of the melt spinning in S2 are that the temperature of region 1 is 300 °C, the temperature of region 2 is 315 °C, the temperature of region 3 is 310 °C, and the temperature of region 4 is 305 °C.

[0038] The solute of the dispersion liquid in S3 is triethylamine, the solvent is water, and the concentration of the dispersion liquid is 0.5 wt%. The standing time in S3 is 3 min, the temperature of the cryogenic treatment is -196 °C, and the time is 1 s.

[0039] An organic solvent is used for elution in S3, and the organic solvent is ethanol. In the fruit acid auxiliary agent containing protein in S3, corn protein accounts for 10 wt%, tannic acid accounts for 2 wt%, and the rest is water.

[0040] In S3, the aerogel composite fiber is immersed in the fruit acid auxiliary agent containing protein for reaction, the reaction time is 4 h, and the reaction temperature is 30 °C. The temperature of the preliminary drying in S3 is 60 °C, and the time is 50 min. The temperature of the drying in S3 is 120 °C, and the time is 120 min.

[0041] The heat-insulating and heat-preserving aerogel fiber produced in Example 1 has a fineness of 9 dtex, a density of 1.0 g / cm 3 , a breaking strength of 4.05 cN / dtex, a bulk height of 5.1 cm, a thermal conductivity of 0.02 w / m·K, a moisture content of 2.3%, an evaporation rate of 0.22 g / h, a far-infrared emissivity of 0.89, a far-infrared irradiation temperature of 3.2 °C, and a dyeing evenness of grade 4.

[0042] Example 3 S1. Add corn powder and ethyl orthosilicate to polyester chips, stir at a stirring speed of 500 r / min for 40 min to obtain a blended fiber raw material. S2. Adopt melt spinning. After the mixed fiber raw material melts, it is extruded from the spinning holes and stretched to obtain initial fibers.

[0043] S3. Immerse the initial fibers in a dispersion liquid, let stand, perform cryogenic treatment, and elute to obtain aerogel composite fibers. Then immerse them in a fruit acid auxiliary agent containing protein and react. After washing with water, adopt a treatment method of preliminary drying and re-drying to manufacture heat-insulating and heat-preserving aerogel fibers with a two-layer structure.

[0044] The particle size of the flax powder in S1 is 300 nm. The addition amount of the flax powder in S1 is 10 wt% of the polyester chips. The addition amount of ethyl orthosilicate in S1 is 5 wt% of the polyester chips.

[0045] The process parameters of the melt spinning in S2 are that the temperature in region 1 is 300 °C, the temperature in region 2 is 315 °C, the temperature in region 3 is 310 °C, and the temperature in region 4 is 305 °C.

[0046] The solute of the dispersion liquid in S3 is triethylamine, the solvent is water, and the concentration of the dispersion liquid is 2 wt%. The standing time in S3 is 5 min, the temperature of the cryogenic treatment is -196 °C, and the time is 7 s.

[0047] An organic solvent is used for the elution in S3, and the organic solvent is isopropanol. In the fruit acid auxiliary agent containing protein in S3, wheat protein accounts for 15 wt%, citric acid accounts for 4 wt%, and the rest is water.

[0048] In the above S3, the aerogel composite fiber is immersed in the protein-containing acid auxiliary to react, the reaction time is 5 hours, and the reaction temperature is 32°C. The pre-drying temperature in S3 is 90° C. and the pre-drying time is 60 minutes. In S3, the drying temperature is 150° C. and the drying time is 90 minutes.

[0049] The thermal insulation aerogel fiber produced in Example 1 has a fineness of 0.5 dtex and a density of 0.7 g / cm 3 The breaking strength was 4.54cN / dtex, the bulkiness was 6.1cm, the thermal conductivity coefficient was 0.008w / m K, the moisture content was 3.6%, the evaporation rate was 0.28g / h, the far-infrared emissivity was 0.92, the far-infrared irradiation temperature was 4℃, and the dyeing uniformity was grade 4.

[0050] Comparative Example 1 S1, flax powder and ethyl orthosilicate are added to the dispersion, and the aerogel is obtained through standing, cryogenic treatment, and elution.

[0051] S2. Add aerogel to polyester slices and stir for 35 minutes, stirring speed is 600r / min to obtain blended fiber raw material, and adopt melt spinning, extrude the blended fiber raw material through the spinning hole after melting, and draw to obtain aerogel composite fiber;

[0052] S3. The aerogel composite fiber is immersed in a protein-containing acid auxiliary to react with the fiber, and then washed with water, and then pre-dried and re-dried to produce a two-layer heat-insulating and heat-retaining aerogel fiber. The particle size of the flax powder in S1 is 1 μm. The amount of flax powder added in S1 is 5 wt % of the polyester slice. The amount of ethyl orthosilicate added in S1 was 3 wt % of the polyester slices.

[0053] The solute of the dispersion in S1 is triethylamine, the solvent is water, and the concentration of the dispersion is 1.5 wt %. The standing time in S1 was 4 min, the temperature of the cryogenic treatment was -196 °C, and the time was 7 s. An organic solvent was used for elution in S1, and the organic solvent was isopropanol.

[0054] The process parameters of the melt spinning in S2 were that the temperature of region 1 was 300 °C, the temperature of region 2 was 315 °C, the temperature of region 3 was 310 °C, and the temperature of region 4 was 305 °C.

[0055] In the fruit acid auxiliary agent containing protein in S3, the soy - derived protein accounted for 12 wt%, the citric acid accounted for 3 wt%, and the rest was water. In S3, the reaction time for immersing the aerogel composite fiber in the fruit acid auxiliary agent containing protein and reacting was 4.5 h, and the reaction temperature was 35 °C.

[0056] The temperature of the preliminary drying in S3 was 70 °C, and the time was 55 min. In S3, the drying temperature was 140 °C, and the time was 100 min.

[0057] The heat - insulating and heat - retaining aerogel fiber produced in Comparative Example 1 had a fineness of 1.5 dtex, a density of 0.9 g / cm 3 , a breaking strength of 2.9 cN / dtex, a bulk height of 4.8 cm, a thermal conductivity of 0.04 w / m·K, a moisture content of 1.3%, an evaporation rate of 0.15 g / h, a far - infrared emissivity of 0.83, a far - infrared irradiation temperature of 2 °C, and a dyeing evenness of grade 4.

[0058] Comparative Example 1 shows that when directly mixing cellulose aerogel and SiO2 aerogel as fiber raw materials and extruding and stretching them into fibers, it causes a certain degree of destruction to the structure of the aerogel, and the crushed aerogel structure has an adverse effect on the performance of the fiber. Comparative Example 2

[0059] Select representative Example 1, remove the reaction of immersing in the fruit acid auxiliary containing the protein in step S3 and the subsequent water washing and drying steps, and the rest are all the same as Example 1. As Comparative Example 2, the obtained fiber has no two-layer structure, and the moisture content and dyeing effect of the fiber are significantly reduced. The moisture content is only 0.8%, the dyeing uniformity is Grade 1, indicating that the protein film outer layer significantly enhances the hygroscopicity and dyeing effect of the fiber. Comparative Example 3

[0060] Select representative Example 1, remove the pre-drying and re-drying treatment methods in step S3, dry at 140°C after water washing, dry for 30 min and observe that bubbles are generated on the fiber surface, and dry for 2 h and observe that fine cracks are generated on the fiber surface. By adopting the treatment method of re-drying after pre-drying, the protein film can further coagulate on the surface of the aerogel composite fiber, and it can be avoided that the protein film shrinks rapidly and unevenly at high temperature, resulting in the generation of bubbles, fine patterns, etc., which affect the appearance of the fiber.

[0061] Note: Each test criterion in the examples is as follows. Mechanical properties: Measured according to "GB / T 3923.1-2013". Dyeing uniformity: Measured according to "GB / T 6508-2015". Thermal conductivity: Measured in accordance with "GB / T 35762-2017". Quick-drying performance: Measured according to "GB / T 21655.1-2008". Far-infrared performance: Measured according to "GB / T 30127-2013". Unless otherwise specified, all ratios described in the present invention are mass ratios, all the percentages are mass percentages, and all raw materials are commercially available products.

[0062] Finally, it should be noted that the above are only preferred embodiments of the present invention and do not limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in each of the above embodiments or equivalently replace some of their technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should all be included within the protection scope of the present invention.

Claims

1. A heat-insulating and heat-preserving aerogel fiber having a two-layer structure with an inner layer and an outer layer, The inner layer is SiO ２ an aerogel composite fiber containing an aerogel and a cellulose aerogel, wherein the outer layer is a protein membrane, characterized by the heat-insulating and heat-preserving aerogel fiber.

2. A method for manufacturing a heat-insulating and heat-preserving aerogel fiber, S1: A step of adding plant powder and a silicon source auxiliary agent to fiber raw materials and stirring for 30 to 40 minutes to obtain mixed fiber raw materials, and S2: A step of extruding the mixed fiber raw materials from a spinning hole and then stretching to obtain initial fibers, and S3: A step of immersing the initial fibers in a dispersion liquid, standing, performing cryogenic treatment, elution to obtain aerogel composite fibers, further immersing them in a fruit acid auxiliary agent containing protein and reacting, washing with water, and then performing preliminary drying and re-drying treatments to manufacture a heat-insulating and heat-preserving aerogel fiber having a two-layer structure. Including, characterized by the method for manufacturing a heat-insulating and heat-preserving aerogel fiber

3. The plant of the plant powder is selected from one or more of flax, coniferous trees, sugarcane, cotton, seaweed, puffballs, and corn, the particle size of the plant powder is 300 nm to 2 μm, the silicon source auxiliary agent in S1 is one or more of sodium silicate, silicon tetrachloride, methyl orthosilicate, and ethyl orthosilicate, the fiber raw materials in S1 are one or more of polyester, regenerated cellulose fiber, polyurethane, acrylic, nylon, and acrylic, the stirring speed is 500 to 800 r / min, characterized by the method for manufacturing a heat-insulating and heat-preserving aerogel fiber according to claim 2.

4. The addition amount of the plant powder in S1 is 0.3 to 10 wt% of the active ingredient of the fiber raw materials, the addition amount of the silicon source auxiliary agent in S1 is 1 to 5 wt% of the active ingredient of the fiber raw materials, characterized by the method for manufacturing a heat-insulating and heat-preserving aerogel fiber according to claim 2.

5. The solute of the dispersion liquid in S3 is one or more of sodium bicarbonate, ammonia monohydrate, dimethylamine, triethylamine, aniline, and pyridine, the solvent of the dispersion liquid is water, characterized by the method for manufacturing a heat-insulating and heat-preserving aerogel fiber according to claim 2.

6. The concentration of the dispersion liquid in S3 is 0.5 to 2 wt%, characterized by the method for manufacturing a heat-insulating and heat-preserving aerogel fiber according to claim 2.

7. The standing time in S3 is 3 to 5 minutes, the temperature of the cryogenic treatment in S3 is -196°C, and the time of the cryogenic treatment is 1 to 10 s, An organic solvent is used for the elution in S3, and the organic solvent is one or more of methanol, ethanol, isopropanol, and acetone. The method for producing heat-insulating and heat-preserving aerogel fibers according to claim 2, characterized in that.

8. The fruit acid auxiliary agent containing protein in S3 contains protein, fruit acid, and water. The protein is one or more of soybean-derived protein, wheat protein, pea protein, corn protein, and keratin protein. The fruit acid is one or more of citric acid, malic acid, tannic acid, and tannic acid. The method for producing heat-insulating and heat-preserving aerogel fibers according to claim 2, characterized in that.

9. In the fruit acid auxiliary agent containing the protein, the protein accounts for 10 to 15 wt%, the fruit acid accounts for 2 to 4 wt%, and the balance is water. The method for producing heat-insulating and heat-preserving aerogel fibers according to claim 8, characterized in that.

10. In S3, the reaction time for immersing the aerogel composite fiber in the fruit acid auxiliary agent containing protein and reacting is 4 to 5 hours, and the reaction temperature is 30 to 35 °C. The temperature of the preliminary drying in S3 is 60 °C to 90 °C, and the time is 50 to 60 minutes. In S3, the drying temperature is 120 to 150 °C, and the time is 90 to 120 minutes. The method for producing heat-insulating and heat-preserving aerogel fibers according to claim 8, characterized in that.