Knitted wool fabric dyeing method based on tea residue nanocomposite
By using a dyeing method based on tea residue nanocomposite materials, and utilizing the covalent bond between porous biochar carrier and tea polyphenol-metal complex, combined with chitosan layer and dual-enzyme synergistic reaction, the environmental pollution and color fastness problems in traditional dyeing processes are solved, achieving green and efficient dyeing of knitted wool fabrics.
Patent Information
- Application Number
- CN202511336403.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-18
- Publication Date
- 2025-11-14
AI Technical Summary
The use of heavy metal salts in traditional mordant dyeing processes leads to environmental pollution and health risks. Tea dyeing processes have low color fastness, and existing low-temperature enzymatic hydrolysis processes are time-consuming and have low dye penetration efficiency, making it difficult to achieve green and highly functional dyeing of knitted wool fabrics.
A porous biochar carrier was prepared by using tea residue nanocomposite material and high-temperature carbonization. Combined with tea polyphenol-metal complex and chitosan layer, the stability of dye was improved by covalent bond and photocatalysis. The dyeing process was accelerated by low eutectic solvent and dual enzyme synergistic reaction. Color fixation was achieved by microwave inactivation technology.
It significantly improves the color fastness and antibacterial properties of dyes, shortens dyeing time, reduces energy consumption and wastewater pollution, and the fabrics exhibit high wash fastness and softness, as well as excellent anti-pilling and anti-fuzzing properties.
Smart Images
Figure CN120945689A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of textile dyeing and finishing technology, and in particular to a dyeing method for knitted wool fabrics based on tea residue nanocomposite materials. Background Technology
[0002] Currently, traditional mordant dyeing processes generally rely on heavy metal salts such as potassium aluminum sulfate and potassium dichromate as mordants, achieving color fixation through a three-step process of pre-mordant dyeing, dyeing, and post-mordant dyeing. Although such methods can improve color fastness, the problem of residual chromium and aluminum ions in the wastewater remains difficult to solve, causing not only serious environmental pollution but also potential harm to human health through skin contact.
[0003] One proposed technology involves using natural tea extract to replace synthetic dyes in a tea dyeing process. However, because the binding of tea polyphenols to wool keratin relies primarily on hydrogen bonds and van der Waals forces, the dyed fabric is prone to pigment loss due to friction or washing, resulting in a wash fastness generally below grade 3. Therefore, while environmentally friendly and safe, this method limits functionality. Although some related technologies have proposed using low-temperature enzymatic hydrolysis or auxiliary agents to improve color fastness, the multi-step enzymatic reaction system is time-consuming, and the dye penetration efficiency is low at low temperatures, making it difficult to improve color fastness and affecting the fabric's performance. Therefore, further research is needed to develop a green and highly functional dyeing method for knitted wool fabrics. Summary of the Invention
[0004] In order to obtain a green and highly functional dyeing method for knitted wool fabrics, this application provides a dyeing method for knitted wool fabrics based on tea residue nanocomposite materials.
[0005] The dyeing method for knitted wool fabric based on tea residue nanocomposite materials provided in this application adopts the following technical solution:
[0006] A dyeing method for knitted wool fabric based on tea residue nanocomposite materials includes the following steps:
[0007] S1. Crush the waste green tea residue, add a degumming agent and degumm at low temperature to remove pectin and caffeine;
[0008] S2. High-temperature carbonization of degummed tea residue was used to prepare porous biochar carrier. The porous biochar carrier was mixed with tea polyphenols and zinc / aluminum complex in a certain ratio, and ZnO-CS core-shell structured nanoparticles with a particle size of 20-30nm were synthesized by co-precipitation method.
[0009] S3. Core-shell structured nanoparticles are added to a low-temperature dyeing solution to form a uniform dispersion system. A low eutectic solvent is added to the uniform dispersion system to reduce the swelling resistance of wool fabric fibers.
[0010] S4. Add polyphenol oxidase to the uniformly dispersed system to catalyze the oxidation of tea polyphenols to generate o-benzoquinone intermediate. Introduce air or oxygen to maintain the oxygen content of the reaction system and ensure the continuous catalytic activity of polyphenol oxidase.
[0011] S5. Immerse the dyed wool fabric in a chitosan acetate solution. Chitosan molecules combine with the exposed amino groups on the surface of the wool fabric fibers through electrostatic adsorption to form a dense protective layer.
[0012] S6. Prepare a dual-enzyme synergistic solution. Immerse the dyed wool fabric in the dual-enzyme synergistic solution and stir slowly. After the reaction is complete, microwave inactivation and color fixation are performed on the wool fabric.
[0013] By employing the above technical solution, porous biochar carriers are prepared using green and safe waste green tea residue as raw material through high-temperature carbonization. The porous structure of the biochar carrier can adsorb dye molecules. The hydroxyl and carboxyl functional groups on its surface bind with the amino and carboxyl groups of wool keratin through hydrogen bonds, forming physical anchoring sites. The biochar carrier is loaded with tea polyphenol-metal complexes, which enhances the covalent bonding with wool keratin, thereby improving the colorfastness and stability of the dye. Antibacterial function is achieved through the photocatalytic activity of ZnO, and UV resistance is enhanced through the chitosan layer. The synergistic effect of the polar and non-polar properties of the eutectic solvent relaxes the gaps between wool scale layers, reducing fiber swelling resistance and making it easier for dye molecules to enter the fiber interior. This process improves dyeing results in one step. Ortho-benzoquinone binds to the amino and thiol groups of wool keratin via a Michael addition reaction, forming stable CN or CS covalent bonds. Maintaining the oxygen content of the reaction system by introducing air or oxygen ensures the continuous catalytic activity of polyphenol oxidase. Experiments show that the amount of quinone generated at this stage is linearly positively correlated with the dye fixation rate, significantly improving the dye fixation rate. Chitosan solution seals the fiber surface, reducing the loss of active groups. Combined with microwave inactivation and fixation technology, it accelerates dye penetration, significantly shortening the dyeing time. Furthermore, the temperature throughout the process is controlled within the wool's tolerance range, effectively alleviating fiber damage in wool fabrics, increasing the strength retention rate to over 90%, effectively preventing felting and deformation, and maintaining the fabric's soft feel.
[0014] Optionally, in step S1, the degumming agent is a 5% sodium carbonate solution with a solid-liquid ratio of 1:8, the degumming temperature does not exceed 40°C, and the degumming time is not less than four hours.
[0015] By adopting the above technical solution, the degumming agent is a 5% sodium carbonate solution with a solid-liquid ratio of 1:8, which allows sodium carbonate to fully react with pectin and caffeine in tea residue at low temperature to generate soluble sodium salts. This selectively extracts active ingredients such as tea polyphenols and flavonoids, improves the degumming effect, and lays the foundation for the subsequent preparation of porous biochar carriers. The comprehensive utilization rate of tea residue reaches 92%.
[0016] Optionally, in step S2, the temperature for preparing the porous biochar support is 500-700℃, the carbonization time is 1.5-2.5 hours, and the mass ratio of the zinc / aluminum complex is 3:1.
[0017] By adopting the above technical solution, a structurally stable bioactive carrier with both adsorption and catalytic functions can be prepared, which also has photocatalytic antibacterial and ultraviolet shielding functions.
[0018] Optionally, in step S3, the eutectic solvent includes a 10% choline chloride / urea solution.
[0019] By adopting the above technical solution, the 10% choline chloride / urea eutectic solvent can relax the gaps between wool scales and reduce the swelling resistance of wool fabric fibers through the synergistic effect of its polar and non-polar properties, making it easier for dye molecules to enter the fiber interior, thereby accelerating the dyeing process and shortening the dyeing cycle.
[0020] Optionally, in step S5, after forming a dense protective layer, the wool fabric is subjected to intermittent microwave irradiation.
[0021] By employing the above technical solution, intermittent microwave irradiation of wool fabric can accelerate the orientation and alignment of chitosan molecular chains, forming a uniform and dense film, significantly improving the density of the chitosan film and enhancing the UV resistance of the wool fabric.
[0022] Optionally, in step S6, the specific operation for preparing the dual-enzyme synergistic solution is as follows: dissolve 1% owf keratinase and 0.5% owf laccase in phosphate buffer at pH 5.0, then preheat in a 50°C water bath for 10 minutes, and then add 0.1 mol / L calcium chloride as an activator for laccase to enhance its oxidative activity.
[0023] Optionally, in step S6, when the dyed wool fabric is immersed in the dual-enzyme synergistic solution and stirred slowly, the bath ratio is 1:30, the stirring speed is 40 rpm, and after reacting for 15 minutes, the temperature is raised to 50°C and the reaction continues for another 15 minutes.
[0024] By adopting the above technical solution, through the synergistic effect of keratinase and laccase, and through stepwise enzymatic hydrolysis and oxidation reaction, the color fastness, softness and anti-pilling properties of the fabric are significantly improved, and the functional enhancement and physical property optimization of dyed wool fabric are achieved under mild low-temperature conditions.
[0025] Optionally, in step S6, the specific operation of microwave inactivation and color fixation is as follows: after the reaction is completed, the wool fabric is placed in a microwave field with a frequency of 2450MHz and a power of 300W for intermittent irradiation 2-3 times, each lasting 2-3 minutes.
[0026] By adopting the above technical solution, the wool fabric after the reaction is completed is intermittently irradiated in a microwave field with a frequency of 2450MHz and a power of 300W. The microwave energy can instantly raise the temperature of the wool fabric to 90℃, thereby rapidly denaturing the tertiary structure of the enzyme protein and terminating the catalytic reaction. At the same time, the thermal effect of the microwave promotes the curing of the cross-linked structure and improves the stability of color fastness.
[0027] In summary, this application includes at least one of the following beneficial technical effects:
[0028] 1. In step S2 of this application, porous biochar carrier is mixed with tea polyphenols and zinc / aluminum complex in a certain ratio to form core-shell structured nanoparticles. The porous structure of the porous biochar carrier can adsorb dye molecules. The functional groups such as hydroxyl and carboxyl groups on its surface are combined with the amino and carboxyl groups of wool keratin through hydrogen bonds to form physical anchoring sites, which significantly enhances the covalent bonding between dye and fiber. At the same time, it endows the fabric with photocatalytic antibacterial properties, completely eliminates the risk of heavy metal pollution, and reduces the COD value of wastewater.
[0029] 2. The introduction of choline chloride / urea eutectic solvent can reduce the swelling resistance of wool fabric fibers. Combined with microwave intermittent irradiation technology, it can accelerate dye penetration and significantly shorten the dyeing time.
[0030] 3. The synergistic effect of keratinase and laccase, through stepwise enzymatic hydrolysis and oxidation reactions, achieves functional enhancement and physical property optimization of dyed wool fabrics under mild conditions, significantly improving the color fastness, softness and anti-pilling properties of the fabrics.
[0031] 4. After the reaction is complete, the wool fabric is intermittently irradiated in a microwave field with a frequency of 2450MHz and a power of 300W. The microwave energy can instantly raise the temperature of the wool fabric to 90℃, thereby rapidly denaturing the tertiary structure of the enzyme protein and terminating the catalytic reaction. At the same time, the thermal effect of the microwave promotes the curing of the cross-linked structure and improves the stability of color fastness. Attached Figure Description
[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0033] Figure 1 This is a flowchart of a dyeing method for knitted wool fabric based on tea residue nanocomposite materials, as described in this application. Detailed Implementation
[0034] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.
[0035] Example 1:
[0036] This application discloses a dyeing method for knitted wool fabric based on tea residue nanocomposite materials. This embodiment focuses on dyeing a light gray knitted wool sweater, referring to... Figure 1 The dyeing method for knitted wool fabric based on tea residue nanocomposite materials includes the following steps:
[0037] S1. Crush the waste green tea residue, add a degumming agent and degumm at low temperature to remove pectin and caffeine;
[0038] S2. High-temperature carbonization of degummed tea residue was used to prepare porous biochar carrier. The porous biochar carrier was mixed with tea polyphenols and zinc / aluminum complex in a certain ratio, and ZnO-CS core-shell structured nanoparticles with a particle size of 20-30nm were synthesized by co-precipitation method.
[0039] S3. Core-shell structured nanoparticles are added to a low-temperature dyeing solution to form a uniform dispersion system. A low eutectic solvent is added to the uniform dispersion system to reduce the swelling resistance of wool fabric fibers.
[0040] S4. Add polyphenol oxidase to the uniformly dispersed system to catalyze the oxidation of tea polyphenols to generate o-benzoquinone intermediate. Introduce air or oxygen to maintain the oxygen content of the reaction system and ensure the continuous catalytic activity of polyphenol oxidase.
[0041] S5. Immerse the dyed wool fabric in a chitosan acetate solution. Chitosan molecules combine with the exposed amino groups on the surface of the wool fabric fibers through electrostatic adsorption to form a dense protective layer.
[0042] S6. Prepare a dual-enzyme synergistic solution. Immerse the dyed wool fabric in the dual-enzyme synergistic solution and stir slowly. After the reaction is complete, microwave inactivation and color fixation are performed on the wool fabric.
[0043] In step S1, the waste green tea residue is made from the residue of Yuhuangjian green tea. The green tea residue is crushed to 40-60 mesh using a pulverizer, and then a 5% sodium carbonate solution with a solid-liquid ratio of 1:8 is added. The residue is degummed at 40°C for 4 hours. The sodium carbonate reacts fully with the pectin and caffeine in the tea residue at low temperature to generate soluble sodium salts, selectively extracting tea polyphenols and flavonoid active ingredients. The degumming effect is good, and the comprehensive utilization rate of tea residue reaches 92%.
[0044] In step S2, the specific operation for preparing the porous biochar carrier involves carbonizing degummed tea residue at 600℃ for 2 hours to prepare the porous biochar carrier. The porous structure of the porous biochar carrier enhances the dye adsorption capacity. The mass ratio of the zinc / aluminum complex is 3:1, and the resulting ZnO-CS core-shell structured nanoparticles possess both adsorption and catalytic functions. The loading of the ZnO-CS nanoparticles is 0.8%, utilizing the photocatalytic activity of ZnO to impart antibacterial function to the fabric.
[0045] In step S3, core-shell nanoparticles are added to a low-temperature dye bath to form a uniformly dispersed system. The temperature of this dye bath is set at 40°C and the pH is 4.5. The core-shell nanoparticles can adsorb dye molecules. The hydroxyl and carboxyl functional groups on their surface are bonded to the amino and carboxyl groups of wool keratin through hydrogen bonds, forming physical anchoring sites and enhancing the adsorption performance of the dye. The added eutectic solvent is a 10% choline chloride / urea solution, and the reaction time is set at 40 minutes. The synergistic effect of the polarity and nonpolarity of the eutectic solvent can relax the gaps between the wool scales of the wool fabric, thereby reducing the fiber swelling resistance and making it easier for dye molecules to enter the fiber interior, thus improving the dyeing efficiency.
[0046] In step S4, the added polyphenol oxidase concentration was 200 U / mL. The temperature of the uniformly dispersed system was then raised to 60°C, the pH was adjusted to 5.5, and the reaction time was set to 40 minutes. The polyphenol oxidase catalyzes the oxidation of tea polyphenols in the porous biochar support to form o-benzoquinone intermediates. O-benzoquinone binds to the amino and thiol groups of wool keratin via a Michael addition reaction, forming stable CN or CS covalent bonds. Experiments show that the amount of quinone produced in this stage is linearly positively correlated with the dye fixation rate, thus significantly improving color fastness. Simultaneously, air or oxygen was introduced during the reaction to maintain the oxygen content of the reaction system, ensuring the continuous catalytic activity of the polyphenol oxidase.
[0047] In step S5, the concentration of the chitosan acetate solution immersed in the dyed wool fabric is set to 5%, the temperature is controlled at 30℃, the pH is 5.0, and the reaction time lasts for 15 minutes. Chitosan molecules in the chitosan acetate solution combine with the exposed amino groups on the surface of the wool fabric fibers through electrostatic adsorption, forming a dense protective layer. This seals the surface active groups of the wool fabric fibers, terminates the oxidation reaction, and simultaneously improves the UV resistance and antistatic properties.
[0048] In addition, after forming a dense protective layer, the wool fabric is subjected to intermittent microwave irradiation. The specific operation of intermittent microwave irradiation is as follows: the wool fabric is taken out and placed in a microwave field for intermittent irradiation twice, each time lasting 2 minutes. The frequency of this microwave field is 2450MHz and the power is 300W. Intermittent microwave irradiation can accelerate the orientation and alignment of chitosan molecular chains, thereby increasing the density of the dense protective layer and improving its UV resistance.
[0049] In step S6, the specific operation for preparing the dual-enzyme synergistic solution is as follows: 1% owf keratinase and 0.5% owf laccase are dissolved in phosphate buffer at pH 5.0, then preheated in a water bath at 50°C for 10 minutes, and then 0.1 mol / L calcium chloride is added as an activator for laccase to enhance its oxidative activity.
[0050] In step S5, when the dyed wool fabric is immersed in the dual-enzyme synergistic solution and slowly stirred at a liquor ratio of 1:30, the reaction is carried out at 40 rpm for 15 minutes. Then, the temperature is raised to 50°C and the reaction continues for another 15 minutes to ensure the full activity of keratinase and laccase. During this process, keratinase selectively hydrolyzes the wool cuticle layer, exposing more active hydroxyl groups, while laccase catalyzes the oxidative cross-linking of tea polyphenols, forming a dense antibacterial network. This process achieves functional enhancement and physical property optimization of the dyed wool fabric under mild conditions, significantly improving the fabric's color fastness, softness, and anti-pilling properties.
[0051] Furthermore, in step S6, the specific operation of microwave inactivation and color fixation is as follows: the wool fabric after the reaction is completed is placed in a microwave field with a frequency of 2450MHz and a power of 300W for intermittent irradiation twice, each time lasting 3 minutes, to inactivate the activity of keratinase and laccase, terminate the catalytic reaction, and the fabric finally exhibits excellent performance: a UPF value as high as 58.2, an antibacterial rate of 99.3% against Staphylococcus aureus, a wash fastness of 4-5, a rubbing fastness of 5, and a felting shrinkage rate of only 2.1%. At the same time, the thermal effect of microwaves promotes the curing of cross-linked structures, further improving the stability of color fastness. This dyeing method does not require high-temperature treatment throughout the process, reduces energy consumption by 50%, and reduces the COD value of wastewater by 70% compared with traditional processes, achieving a perfect combination of eco-friendliness and functionality.
[0052] The implementation principle of the dyeing method for knitted wool fabric based on tea residue nanocomposite materials in this application is as follows: Green tea residue is degummed by 5% Na2CO3 solution to remove pectin and caffeine, and then carbonized at high temperature. After loading with 0.8% ZnO-CS nanoparticles, core-shell structured nanoparticles with both adsorption and catalytic functions are formed. The dyeing process adopts a low-temperature gradient method: In the pre-dyeing stage, the wool sweater is soaked in a dye solution with core-shell structured nanoparticles at 40℃ for 30 minutes. The porous structure of biochar and the synergistic effect of tea polyphenol-zinc / aluminum complex allow dye molecules to penetrate evenly into the wool fabric fibers. Then, the temperature is raised to 60℃, and polyphenol oxidase is added to catalyze the oxidation of tea polyphenols to generate o-benzoquinone intermediates, which form covalent bonds with the amino groups of wool keratin, significantly improving the color fastness. Finally, the color is fixed at 30℃ with 5% owf chitosan solution for 15 minutes. Chitosan molecules seal the active sites on the fiber surface through electrostatic adsorption, forming an anti-ultraviolet protective layer. In the post-finishing stage, a dual-enzyme system of keratinase and laccase is used at pH 5.0 and 50℃ for 30 minutes. Keratinase selectively hydrolyzes the wool scale layer, exposing more active hydroxyl groups, while laccase catalyzes the oxidative cross-linking of tea polyphenols, forming a dense antibacterial network. After microwave intermittent irradiation to inactivate enzyme activity, the fabric ultimately exhibits excellent performance: a UPF value as high as 58.2, a 99.3% inhibition rate against Staphylococcus aureus, a wash fastness of 4-5, a rubbing fastness of 5, and a felting shrinkage rate of only 2.1%. This process requires no high-temperature treatment throughout, reducing energy consumption by 50%, and reducing the COD value of wastewater by 70% compared to traditional processes, achieving a perfect combination of eco-friendliness and functionality.
[0053] Example 2:
[0054] This application discloses a dyeing method for knitted wool fabric based on tea residue nanocomposite materials. This embodiment focuses on dyeing a dark brown knitted wool scarf, employing the dyeing method of Example 1. The difference between Example 2 and Example 1 is that this application uses oolong tea residue as raw material, with a ZnO-CS nanoparticle loading of 1.2% in the core-shell structured nanoparticles. These core-shell structured nanoparticles possess both photocatalytic antibacterial and UV shielding functions. During the dyeing stage, a high liquor ratio of 1:40 is used in conjunction with a synergistic effect of a choline chloride / urea eutectic solvent. Dyeing is performed at 80°C for 60 minutes. The eutectic solvent effectively relaxes the gaps between the wool scale layers, increasing dye penetration efficiency by 3 times. Furthermore, to further accelerate the reaction process, microwave intermittent irradiation is performed three times, each lasting 2 minutes. The microwave thermal effect promotes the cross-linking reaction between quinones and keratin, while simultaneously reducing energy consumption by 40%. Furthermore, in the dual-enzyme synergistic solution, keratinase and laccase are mixed in a 2:1 ratio. After the dyed wool fabric is immersed in the dual-enzyme synergistic solution, it is treated for 30 minutes at pH 5.0 and 50℃. This process enzymatically hydrolyzes the scale layer while catalyzing the formation of stable covalent bonds, ultimately endowing the scarf with excellent properties: a UPF value of 53.7, UVB transmittance of less than 1%, a wash fastness grade of 4, and a strength retention rate of 91.5%. In this application embodiment, the process temperature is controlled below 80℃ throughout, effectively preventing wool felting and controlling the felting rate to below 3%, thus achieving green manufacturing of dark-colored functional wool products.
[0055] The above are all optional embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A method for dyeing knitted wool fabric based on tea residue nanocomposite materials, characterized in that, Includes the following steps: S1. Crush the waste green tea residue, add a degumming agent and degumm at low temperature to remove pectin and caffeine; S2. High-temperature carbonization of degummed tea residue was used to prepare porous biochar carrier. The porous biochar carrier was mixed with tea polyphenols and zinc / aluminum complex in a certain ratio, and ZnO-CS core-shell structured nanoparticles with a particle size of 20-30nm were synthesized by co-precipitation method. S3. Core-shell structured nanoparticles are added to a low-temperature dyeing solution to form a uniform dispersion system. A low eutectic solvent is added to the uniform dispersion system to reduce the swelling resistance of wool fabric fibers. S4. Add polyphenol oxidase to the uniformly dispersed system to catalyze the oxidation of tea polyphenols to generate o-benzoquinone intermediate. Introduce air or oxygen to maintain the oxygen content of the reaction system and ensure the continuous catalytic activity of polyphenol oxidase. S5. Immerse the dyed wool fabric in a chitosan acetate solution. Chitosan molecules combine with the exposed amino groups on the surface of the wool fabric fibers through electrostatic adsorption to form a dense protective layer. S6. Prepare a dual-enzyme synergistic solution. Immerse the dyed wool fabric in the dual-enzyme synergistic solution and stir slowly. After the reaction is complete, microwave inactivation and color fixation are performed on the wool fabric.
2. The dyeing method for knitted wool fabric based on tea residue nanocomposite materials according to claim 1, characterized in that: In step S1, the degumming agent is a 5% sodium carbonate solution with a solid-liquid ratio of 1:8, the degumming temperature does not exceed 40°C, and the degumming time is not less than four hours.
3. The dyeing method for knitted wool fabric based on tea residue nanocomposite materials according to claim 1, characterized in that: In step S2, the temperature for preparing the porous biochar support is 500-700℃, the carbonization time is 1.5-2.5 hours, and the mass ratio of the zinc / aluminum complex is 3:
1.
4. The dyeing method for knitted wool fabric based on tea residue nanocomposite materials according to claim 1, characterized in that: In step S3, the eutectic solvent includes a 10% choline chloride / urea solution.
5. The dyeing method for knitted wool fabric based on tea residue nanocomposite materials according to claim 1, characterized in that: In step S5, after forming a dense protective layer, the wool fabric is subjected to intermittent microwave irradiation.
6. The dyeing method for knitted wool fabric based on tea residue nanocomposite materials according to claim 1, characterized in that: In step S6, the specific operation for preparing the dual-enzyme synergistic solution is as follows: 1% owf keratinase and 0.5% owf laccase are dissolved in phosphate buffer at pH 5.0, then preheated in a water bath at 50°C for 10 minutes, and then 0.1 mol / L calcium chloride is added as an activator for laccase to enhance its oxidative activity.
7. The dyeing method for knitted wool fabric based on tea residue nanocomposite materials according to claim 6, characterized in that: In step S6, when the dyed wool fabric is immersed in the dual-enzyme synergistic solution and stirred slowly, the bath ratio is 1:30, the stirring speed is 40 rpm, and after reacting for 15 minutes, the temperature is raised to 50°C and the reaction continues for another 15 minutes.
8. The dyeing method for knitted wool fabric based on tea residue nanocomposite materials according to claim 7, characterized in that: In step S6, the specific operation of microwave inactivation and color fixation is as follows: After the reaction is completed, the wool fabric is placed in a microwave field with a frequency of 2450MHz and a power of 300W for intermittent irradiation 2-3 times, each lasting 2-3 minutes.