A method for increasing the molecular weight of nylon 6 carpet fibers

Abstract

This invention discloses a method for increasing the molecular weight of nylon 6 carpet fibers, comprising the following steps: S1, cleaning waste nylon 6 carpet fibers to remove surface impurities, then drying the cleaned fibers, and finally crushing the dried fibers into fiber fragments of appropriate size; S2, preparing a 0.1%-1% organic or inorganic acid solution and immersing the waste nylon 6 carpet fibers in the acid solution. In this invention, with the fibers in a pre-swollen state, using benzyl alcohol as the reaction medium, a fiber-to-benzyl alcohol ratio of 1:20, formic acid to adjust the pH to approximately 5-6, and a fiber-to-glutaraldehyde molar ratio of 1:5, a crosslinking reaction is carried out at 100℃ for 1 hour to obtain a good chain extension effect. Utilizing the aldehyde-amine reaction to achieve crosslinking and chain extension of PA6 aims to design and optimize a greener and more convenient molecular weight multiplication pathway, providing a new approach for the recycling and reuse of polyamide fibers, and conforming to the concept of green development.

Description

Technical Field

[0001] This invention relates to the field of nylon technology, and more particularly to a method for increasing the molecular weight of nylon 6 carpet fibers. Background Technology

[0002] Polyamide (PA), commonly known as nylon, is a synthetic polymer material. Nylon is a synthetic fiber made from polyamide through melt spinning, and it possesses good mechanical properties and abrasion resistance. The recycling of waste nylon fibers has always been a matter of widespread concern.

[0003] Currently, there are two main methods for preparing recycled nylon fibers from waste polyamide materials: physical recycling and chemical recycling. Physical recycling technology is relatively mature. However, physically recycled nylon fibers suffer from drawbacks such as low strength and uneven dyeing, resulting in poor product quality and limiting their use to low- to mid-range fabrics. Therefore, domestic and international manufacturers and experts have begun to focus their research on chemically recycled nylon fibers.

[0004] To address the above issues, we have developed a method for increasing the molecular weight of nylon 6 carpet fibers. Summary of the Invention

[0005] This invention discloses a method for increasing the molecular weight of nylon 6 carpet fibers, aiming to solve the technical problems in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for increasing the molecular weight of nylon 6 carpet fibers includes the following steps:

[0008] S1. Clean the waste nylon 6 carpet fibers to remove surface impurities, then dry the cleaned fibers, and finally crush the dried fibers into fiber fragments of appropriate size.

[0009] Step S1 can be further refined as follows:

[0010] S11. Prepare an appropriate amount of clean water and detergent, soak the waste nylon 6 carpet fibers in the detergent solution, and stir well.

[0011] S12. Use a brush or mechanical equipment to clean the fibers to ensure that all dirt and impurities are removed;

[0012] S13. Place the washed fibers in a dry area to air dry naturally or use a drying device to dry them.

[0013] S14. Use a shredder to shred the dried fibers to ensure that the fiber fragments are of appropriate size for subsequent processing.

[0014] S2. Prepare an organic or inorganic acid solution with a concentration of 0.1%-1%, immerse the waste nylon 6 carpet fibers in the acid solution, control the treatment temperature at 70-100℃, and immerse for 30-60 minutes to ensure that the fibers are fully cationicized.

[0015] Step S2 can be further refined as follows:

[0016] S21. In the laboratory, accurately weigh organic or inorganic acids to prepare 0.1%-1% acid solutions.

[0017] S22. Distribute the waste nylon 6 carpet fibers evenly in the acid solution, ensuring that all fibers come into contact with the acid solution;

[0018] S23. Heat the acid solution to 70-100℃ and maintain this temperature for 30-60 minutes;

[0019] S24. Stir the solution regularly to ensure uniform cationization treatment of the fibers.

[0020] S3. Prepare a solution of benzyl alcohol and formic acid, with a ratio of benzyl alcohol to formic acid of 1:10-20. Immerse the cationized fiber in the swelling solution. The swelling treatment temperature is 50-100℃ and the treatment time is 1-1.5 hours.

[0021] Step S3 can be further refined as follows:

[0022] S31. Accurately weigh benzyl alcohol and formic acid, and prepare a solution at a ratio of 1:10-20.

[0023] S32. Remove the cationized fiber from the acid solution and rinse it gently with water to remove excess acid;

[0024] S33. Place the rinsed fibers into the prepared benzyl alcohol and formic acid solution to ensure that the fibers are completely soaked;

[0025] S34. Heat the swollen solution to 50-100℃ and maintain this temperature for 1-1.5 hours, stirring the solution periodically during this period.

[0026] S4. Prepare the reaction medium solution, mainly benzyl alcohol, add an appropriate amount of formic acid as a reducing agent to the reaction medium, and prepare glutaraldehyde solution as a crosslinking chain extender.

[0027] Step S4 can be further refined as follows:

[0028] S41. Prepare a solution of benzyl alcohol and formic acid in proportion, ensuring that the solution is mixed evenly;

[0029] S42. Accurately weigh glutaraldehyde and prepare a glutaraldehyde solution of a certain concentration.

[0030] S43. Gradually add the glutaraldehyde solution to the benzyl alcohol and formic acid solutions, stirring until well mixed;

[0031] S44. Ensure that the reaction medium solution is in a uniform and stable state before use.

[0032] S5. Place the swollen nylon 6 fiber in the reaction medium and mix it with glutaraldehyde solution at a molar ratio of 1:1 to 1:8. Control the reaction temperature at 100-120℃ and the reaction time at 1-3 hours.

[0033] Step S5 can be further refined as follows:

[0034] S51. Remove the swollen nylon 6 fibers from the swelling solution and gently remove excess solution.

[0035] S52. Place the fibers into the prepared reaction medium, ensuring that the fibers are evenly distributed;

[0036] S53. Add glutaraldehyde solution to the reaction medium at a molar ratio of 1:1 to 1:8 and stir until homogeneous;

[0037] S54. Heat the reaction medium to 100-120℃ and maintain the reaction time for 1-3 hours. Stir the solution regularly during the process to ensure that the reaction proceeds fully.

[0038] S6. After the reaction is complete, remove the fiber from the reaction solution, wash the fiber with pure water to remove residual reactants and byproducts, and then dry the washed fiber.

[0039] Step S6 can be further refined as follows:

[0040] S61. After the reaction is complete, remove the fiber from the reaction medium and gently remove any excess solution.

[0041] S62. Wash the fibers multiple times with plenty of pure water to remove residual reactants and byproducts.

[0042] S63. Place the washed fibers in a dry area to air dry naturally or use a drying device for drying.

[0043] S64. Inspect the dried fibers to ensure there is no residual moisture or impurities.

[0044] S7. Test the change in molecular weight of nylon 6 fiber before and after treatment, detect the mechanical properties of the fiber, including tensile strength and elongation at break, and check the abrasion resistance and dyeing uniformity of the fiber.

[0045] Step S7 can be further refined as follows:

[0046] S71. Use gel permeation chromatography (GPC) or other appropriate methods to test the change in molecular weight of the fibers before and after treatment;

[0047] S72. Use a tensile testing machine to test the tensile strength and elongation at break of the fiber;

[0048] S73. Conduct abrasion resistance tests to evaluate the fiber's performance under abrasion conditions;

[0049] S74. Conduct a dyeing test to check the dyeing uniformity and color fastness of the fibers.

[0050] S8. Use the treated nylon 6 fiber in textile production to verify its industrial feasibility, evaluate the performance of recycled nylon 6 fiber in different application fields, record and analyze the cost-effectiveness of the treatment process, and provide data support for large-scale production.

[0051] Step S8 can be further refined as follows:

[0052] S81. The treated nylon 6 fiber was sent to a textile factory for actual production testing to observe the fiber’s performance in the textile process.

[0053] S82. Collect and analyze data on the application of recycled nylon 6 fiber in different textile products;

[0054] S83. Evaluate the cost-effectiveness of the processing technology, including material costs, energy consumption, and production efficiency;

[0055] S84. Based on the test data, propose improvement suggestions to provide data support and process optimization solutions for large-scale production.

[0056] The method for increasing the molecular weight of nylon 6 carpet fibers provided by this invention has the following advantages:

[0057] This invention utilizes reductive amination as the reaction mechanism, taking advantage of the reductive amination reaction between the amino groups at the ends of the nylon 6 fiber molecular chains and glutaraldehyde to multiply and extend the molecular chains in the amorphous regions of the nylon 6 fiber, thereby increasing the molecular weight of the amorphous regions. In the pre-swollen state of the fiber, using benzyl alcohol as the reaction medium, with a fiber-to-benzyl alcohol ratio of 1:20, formic acid adjusting the pH to approximately 5-6, and a fiber-to-glutaraldehyde molar ratio of 1:5, the crosslinking reaction is carried out at 100℃ for 1 hour, achieving a good chain extension effect. The use of the aldehyde-amine reaction to achieve crosslinking and chain extension of PA6 aims to design and optimize a greener and more convenient molecular weight multiplication pathway, providing a new approach for the recycling and reuse of polyamide fibers, and aligning with the concept of green development. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of the overall process of a method for increasing the molecular weight of nylon 6 carpet fibers proposed in this invention.

[0059] Figure 2 This is a schematic diagram of step S1 of a method for increasing the molecular weight of nylon 6 carpet fibers proposed in this invention.

[0060] Figure 3 This is a schematic flow chart of step S2 of a method for increasing the molecular weight of nylon 6 carpet fibers proposed in this invention.

[0061] Figure 4 This is a schematic flow chart of step S3 of a method for increasing the molecular weight of nylon 6 carpet fibers proposed in this invention.

[0062] Figure 5 This is a schematic flow chart of step S4 of a method for increasing the molecular weight of nylon 6 carpet fibers proposed in this invention.

[0063] Figure 6 This is a schematic flow chart of step S5 of a method for increasing the molecular weight of nylon 6 carpet fibers proposed in this invention.

[0064] Figure 7 This is a schematic flow chart of step S6 of a method for increasing the molecular weight of nylon 6 carpet fibers proposed in this invention.

[0065] Figure 8 This is a schematic flow chart of step S7 of a method for increasing the molecular weight of nylon 6 carpet fibers proposed in this invention.

[0066] Figure 9 This is a schematic flow chart of step S8 of a method for increasing the molecular weight of nylon 6 carpet fibers proposed in this invention. Detailed Implementation

[0067] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and marked in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0068] This invention discloses a method for increasing the molecular weight of nylon 6 carpet fibers.

[0069] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5, Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown, a method for increasing the molecular weight of nylon 6 carpet fibers includes the following steps:

[0070] S1. Clean the waste nylon 6 carpet fibers to remove surface impurities, then dry the cleaned fibers, and finally crush the dried fibers into fiber fragments of appropriate size.

[0071] Step S1 can be further refined as follows:

[0072] S11. Prepare an appropriate amount of clean water and detergent, soak the waste nylon 6 carpet fibers in the detergent solution, and stir well.

[0073] S12. Use a brush or mechanical equipment to clean the fibers to ensure that all dirt and impurities are removed;

[0074] S13. Place the washed fibers in a dry area to air dry naturally or use a drying device to dry them.

[0075] S14. Use a shredder to shred the dried fibers to ensure that the fiber fragments are of appropriate size for subsequent processing.

[0076] Waste nylon 6 carpet fibers are thoroughly cleaned to remove surface impurities. The cleaned fibers are then air-dried and finally shredded into appropriately sized fiber fragments. The advantages of this process are: firstly, soaking and agitating the cleaning solution ensures thorough penetration of the cleaning agent into every corner of the fiber, guaranteeing a complete clean. Mechanical cleaning further enhances the cleaning power, ensuring the cleanliness of the fiber surface. The drying process, through natural air drying or the use of drying equipment, quickly removes moisture from the fibers, preventing deterioration in a humid environment. The final shredding step, breaking the fibers into appropriately sized fragments, facilitates subsequent processing steps and improves the overall efficiency of the process.

[0077] Soaking and agitation utilize the chemical action of detergents and the permeability of water to dissolve dirt; mechanical cleaning removes stubborn stains through physical friction; drying utilizes airflow or heat to evaporate moisture; and pulverization increases the specific surface area of ​​fibers, improving the penetration and reaction efficiency of subsequent treatment solutions.

[0078] S2. Prepare an organic or inorganic acid solution with a concentration of 0.1%-1%, immerse the waste nylon 6 carpet fibers in the acid solution, control the treatment temperature at 70-100℃, and immerse for 30-60 minutes to ensure that the fibers are fully cationicized.

[0079] Step S2 can be further refined as follows:

[0080] S21. In the laboratory, accurately weigh organic or inorganic acids to prepare 0.1%-1% acid solutions.

[0081] S22. Distribute the waste nylon 6 carpet fibers evenly in the acid solution, ensuring that all fibers come into contact with the acid solution;

[0082] S23. Heat the acid solution to 70-100℃ and maintain this temperature for 30-60 minutes;

[0083] S24. Stir the solution regularly to ensure uniform cationization treatment of the fibers.

[0084] Prepare a 0.1%-1% organic or inorganic acid solution and immerse the waste nylon 6 carpet fibers in it. Maintain the treatment temperature at 70-100℃ for 30-60 minutes to ensure complete cationization of the fibers. The advantage of this process is that accurate weighing of the acid solution ensures precise concentration, thus guaranteeing consistent treatment results. Distribute the fibers evenly in the acid solution, ensuring each fiber is fully in contact with the acid, guaranteeing uniform cationization. Heating the acid solution to 70-100℃ and maintaining this temperature for 30-60 minutes helps accelerate the reaction and improve treatment efficiency. Stir the solution regularly to ensure uniform heating and reaction of the fibers during treatment, achieving optimal cationization results.

[0085] Preparing an acid solution of accurate concentration allows for cationization treatment of the fibers through a chemical reaction; uniform distribution of the fibers and heating of the acid solution ensure sufficient contact and reaction rate between the fibers and the acid solution; timed stirring promotes uniform mixing of the fibers and solution through mechanical force, improving the treatment effect.

[0086] S3. Prepare a solution of benzyl alcohol and formic acid, with a ratio of benzyl alcohol to formic acid of 1:10-20. Immerse the cationized fiber in the swelling solution. The swelling treatment temperature is 50-100℃ and the treatment time is 1-1.5 hours.

[0087] Step S3 can be further refined as follows:

[0088] S31. Accurately weigh benzyl alcohol and formic acid, and prepare a solution at a ratio of 1:10-20.

[0089] S32. Remove the cationized fiber from the acid solution and rinse it gently with water to remove excess acid;

[0090] S33. Place the rinsed fibers into the prepared benzyl alcohol and formic acid solution to ensure that the fibers are completely soaked;

[0091] S34. Heat the swollen solution to 50-100℃ and maintain this temperature for 1-1.5 hours, stirring the solution periodically during this period.

[0092] Prepare a benzyl alcohol and formic acid solution with a benzyl alcohol to formic acid ratio of 1:10-20. Immerse the cationized fibers in the swelling solution at a temperature of 50-100℃ for 1-1.5 hours. The advantage of this process is that accurate weighing of benzyl alcohol and formic acid ensures the precision of the solution ratio, thus guaranteeing consistent swelling effects. Remove the cationized fibers from the acid solution and gently rinse with water to remove excess acid, ensuring a clean environment for subsequent swelling treatment. Immerse the rinsed fibers in the prepared benzyl alcohol and formic acid solution, ensuring complete immersion to facilitate full contact between the swelling agent and the fibers. Heat the swelling solution to 50-100℃ and maintain this temperature for 1-1.5 hours, stirring the solution periodically during this time to accelerate the swelling process and improve treatment efficiency and effectiveness.

[0093] Preparing a solution of benzyl alcohol and formic acid in an accurate ratio allows for effective swelling of the fibers through their dissolving action and chemical reaction. Rinsing the fibers removes excess acid, preventing residual acid from interfering with the swelling process. Heating the swelling solution and stirring at regular intervals increases the temperature and promotes uniform contact between the solution and the fibers, ensuring a highly efficient and uniform swelling process.

[0094] S4. Prepare the reaction medium solution, mainly benzyl alcohol, add an appropriate amount of formic acid as a reducing agent to the reaction medium, and prepare glutaraldehyde solution as a crosslinking chain extender.

[0095] Step S4 can be further refined as follows:

[0096] S41. Prepare a solution of benzyl alcohol and formic acid in proportion, ensuring that the solution is mixed evenly;

[0097] S42. Accurately weigh glutaraldehyde and prepare a glutaraldehyde solution of a certain concentration.

[0098] S43. Gradually add the glutaraldehyde solution to the benzyl alcohol and formic acid solutions, stirring until well mixed;

[0099] S44. Ensure that the reaction medium solution is in a uniform and stable state before use.

[0100] Prepare the reaction medium solution, primarily using benzyl alcohol, with an appropriate amount of formic acid added as a reducing agent. Prepare a glutaraldehyde solution as a cross-linking chain extender. The advantage of this process is that by preparing the benzyl alcohol and formic acid solutions in a specific ratio, the solution is ensured to be uniformly mixed, thereby guaranteeing the stability and consistency of the reaction medium. Accurately weigh the glutaraldehyde and prepare a glutaraldehyde solution of a specific concentration to ensure the accuracy of the reaction dosage and avoid inaccurate dosage leading to poor reaction results. Gradually add the glutaraldehyde solution to the benzyl alcohol and formic acid solutions, stirring thoroughly to ensure uniform mixing, improving the homogeneity of the reaction medium and reaction efficiency. Ensure the reaction medium solution is in a uniform and stable state before use, avoiding precipitation or layering, to ensure the smooth progress of the reaction.

[0101] Prepare benzyl alcohol and formic acid solutions in proportion to provide a stable reaction environment through chemical reaction and dissolution; accurately weigh and prepare glutaraldehyde solution to ensure accurate dosage of crosslinking chain extender; gradually add and thoroughly stir glutaraldehyde solution to ensure uniform mixing of reaction medium and provide uniform reaction conditions; maintain the uniform and stable state of the solution to ensure smooth reaction and consistent reaction results.

[0102] S5. Place the swollen nylon 6 fiber in the reaction medium and mix it with glutaraldehyde solution at a molar ratio of 1:1 to 1:8. Control the reaction temperature at 100-120℃ and the reaction time at 1-3 hours.

[0103] Step S5 can be further refined as follows:

[0104] S51. Remove the swollen nylon 6 fibers from the swelling solution and gently remove excess solution.

[0105] S52. Place the fibers into the prepared reaction medium, ensuring that the fibers are evenly distributed;

[0106] S53. Add glutaraldehyde solution to the reaction medium at a molar ratio of 1:1 to 1:8 and stir until homogeneous;

[0107] S54. Heat the reaction medium to 100-120℃ and maintain the reaction time for 1-3 hours. Stir the solution regularly during the process to ensure that the reaction proceeds fully.

[0108] The swollen nylon 6 fibers are placed in the reaction medium and mixed with glutaraldehyde solution at a molar ratio of 1:1 to 1:8. The reaction temperature is controlled at 100-120℃, and the reaction time is 1-3 hours. The advantage of this process is that the swollen nylon 6 fibers are removed from the swollen solution, and excess solution is gently removed, ensuring that no excess solvent on the fiber surface interferes with subsequent reactions. The fibers are placed in the prepared reaction medium, ensuring uniform distribution to facilitate sufficient contact between the reaction medium and the fibers. Glutaraldehyde solution is added to the reaction medium at a molar ratio of 1:1 to 1:8 and stirred thoroughly to ensure uniform mixing and complete reaction of glutaraldehyde and fibers. The reaction medium is heated to 100-120℃ and maintained for 1-3 hours, with regular stirring to ensure a complete reaction, thereby improving reaction efficiency and effectiveness.

[0109] After swelling treatment, nylon 6 fibers were removed from the swelling solution and excess solution was removed to reduce solvent interference through mechanical methods. The fibers were then evenly distributed in the reaction medium to increase the contact area between the fibers and the reactants. Glutaraldehyde solution was added at a molar ratio and stirred until homogeneous, with the reaction dosage controlled by stoichiometry. The reaction medium was heated and stirred periodically to promote the reaction through thermal energy and mechanical stirring, ensuring the reaction proceeded fully and uniformly.

[0110] S6. After the reaction is complete, remove the fiber from the reaction solution, wash the fiber with pure water to remove residual reactants and byproducts, and then dry the washed fiber.

[0111] Step S6 can be further refined as follows:

[0112] S61. After the reaction is complete, remove the fiber from the reaction medium and gently remove any excess solution.

[0113] S62. Wash the fibers multiple times with plenty of pure water to remove residual reactants and byproducts.

[0114] S63. Place the washed fibers in a dry area to air dry naturally or use a drying device for drying.

[0115] S64. Inspect the dried fibers to ensure there is no residual moisture or impurities.

[0116] After the reaction is complete, the fibers are removed from the reaction solution and washed with pure water to remove residual reactants and byproducts. The washed fibers are then dried. The advantage of this process is that removing the fibers from the reaction medium and gently removing excess solution minimizes interference with subsequent processing. Washing the fibers multiple times with plenty of pure water ensures thorough removal of residual reactants and byproducts, guaranteeing fiber purity. Placing the washed fibers in a dry area to air dry naturally or using drying equipment quickly removes moisture and prevents fiber deterioration in a humid environment. The dried fibers are then inspected to ensure no residual moisture or impurities remain, guaranteeing the final quality of the fibers.

[0117] The fibers are removed from the reaction medium and excess solution is removed, with mechanical methods used to reduce residual solution. The fibers are then washed multiple times with plenty of pure water to remove residual reactants and byproducts through dissolution and rinsing. The fibers are then dried by airflow or thermal evaporation. The dried fibers are inspected to ensure no residual moisture or impurities remain, guaranteeing fiber purity and quality.

[0118] S7. Test the change in molecular weight of nylon 6 fiber before and after treatment, detect the mechanical properties of the fiber, including tensile strength and elongation at break, and check the abrasion resistance and dyeing uniformity of the fiber.

[0119] Step S7 can be further refined as follows:

[0120] S71. Use gel permeation chromatography (GPC) or other appropriate methods to test the change in molecular weight of the fibers before and after treatment;

[0121] S72. Use a tensile testing machine to test the tensile strength and elongation at break of the fiber;

[0122] S73. Conduct abrasion resistance tests to evaluate the fiber's performance under abrasion conditions;

[0123] S74. Conduct a dyeing test to check the dyeing uniformity and color fastness of the fibers.

[0124] The molecular weight change of nylon 6 fibers before and after treatment was tested to assess the fiber's mechanical properties, including tensile strength and elongation at break, and to check abrasion resistance and dyeing uniformity. The advantage of this process is that using gel permeation chromatography (GPC) or other appropriate methods to test the molecular weight change before and after treatment allows for accurate assessment of the fiber's molecular weight change and verification of the treatment effect. Using a tensile testing machine to test the fiber's tensile strength and elongation at break quantifies the fiber's mechanical properties, ensuring it meets application requirements. Abrasion resistance testing evaluates the fiber's performance under abrasion conditions, helping to understand the fiber's durability and application potential. Dyeing tests check the fiber's dyeing uniformity and color fastness, assessing the fiber's performance in the dyeing process and ensuring its quality in the final product.

[0125] Methods such as GPC are used to test molecular weight changes, reflecting the treatment effect through changes in molecular weight distribution; a tensile testing machine is used to test the mechanical properties of the fibers by applying tensile force; abrasion resistance tests are conducted to evaluate the abrasion resistance of the fibers by simulating abrasion environments; and dyeing tests are performed to evaluate the dyeing performance and stability of the fibers by testing dyeing effect and color fastness.

[0126] S8. Use the treated nylon 6 fiber in textile production to verify its industrial feasibility, evaluate the performance of recycled nylon 6 fiber in different application fields, record and analyze the cost-effectiveness of the treatment process, and provide data support for large-scale production.

[0127] Step S8 can be further refined as follows:

[0128] S81. The treated nylon 6 fiber was sent to a textile factory for actual production testing to observe the fiber’s performance in the textile process.

[0129] S82. Collect and analyze data on the application of recycled nylon 6 fiber in different textile products;

[0130] S83. Evaluate the cost-effectiveness of the processing technology, including material costs, energy consumption, and production efficiency;

[0131] S84. Based on the test data, propose improvement suggestions to provide data support and process optimization solutions for large-scale production.

[0132] The process of using treated nylon 6 fiber in textile production verifies its industrial feasibility, evaluates the performance of recycled nylon 6 fiber in different application areas, and records and analyzes the cost-effectiveness of the treatment process to provide data support for large-scale production. The advantages of this process include sending the treated nylon 6 fiber to a textile mill for actual production trials, allowing observation of the fiber's performance during the textile process and verifying its industrial feasibility. Collecting and analyzing application data of recycled nylon 6 fiber in different textile products allows for evaluation of the fiber's performance in various application areas, ensuring its suitability and quality. Evaluating the cost-effectiveness of the treatment process, including material costs, energy consumption, and production efficiency, helps to understand the economics and sustainability of the process. Based on the experimental data, improvement suggestions are proposed, providing data support and process optimization schemes for large-scale production, enabling continuous optimization of the process flow and improving production efficiency and product quality.

[0133] The fibers are sent to textile mills for actual production trials to verify their textile performance through practical operation; application data is collected and analyzed to evaluate the application effect of the fibers; the cost-effectiveness of the processing technology is assessed, and the economics of the process are understood through calculation and comparison; improvement suggestions are made based on the test data, and the process flow is optimized through data-driven approaches to improve overall production efficiency.

[0134] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. The substitutions may be replacements of some structures, devices, or method steps, or they may be complete technical solutions. Equivalent substitutions or modifications made to the technical solutions and inventive concepts of the present invention should all be covered within the scope of protection of the present invention.

Claims

1. A method for increasing the molecular weight of nylon 6 carpet fibers, characterized in that, Includes the following steps: S1. Clean the waste nylon 6 carpet fibers to remove surface impurities, then dry the cleaned fibers, and finally crush the dried fibers into fiber fragments of appropriate size. S2. Prepare an organic or inorganic acid solution with a concentration of 0.1%-1%, immerse the waste nylon 6 carpet fibers in the acid solution, control the treatment temperature at 70-100℃, and immerse for 30-60 minutes to ensure that the fibers are fully cationicized. S3. Prepare a solution of benzyl alcohol and formic acid, with a ratio of benzyl alcohol to formic acid of 1:10-20. Immerse the cationized fiber in the swelling solution. The swelling treatment temperature is 50-100℃ and the treatment time is 1-1.5 hours. S4. Prepare the reaction medium solution, using benzyl alcohol as the reaction medium, add an appropriate amount of formic acid as a reducing agent to the reaction medium, and prepare glutaraldehyde solution as a crosslinking chain extender. S5. Place the swollen nylon 6 fiber in the reaction medium and mix it with glutaraldehyde solution at a molar ratio of 1:1 to 1:

8. Control the reaction temperature at 100-120℃ and the reaction time at 1-3 hours. S6. After the reaction is complete, remove the fiber from the reaction solution, wash the fiber with pure water to remove residual reactants and byproducts, and then dry the washed fiber. S7. Test the change in molecular weight of nylon 6 fiber before and after treatment, detect the mechanical properties of the fiber, including tensile strength and elongation at break, and check the abrasion resistance and dyeing uniformity of the fiber. S8. Use the treated nylon 6 fiber in textile production to verify its industrial feasibility, evaluate the performance of recycled nylon 6 fiber in different application fields, record and analyze the cost-effectiveness of the treatment process, and provide data support for large-scale production.

2. The method for increasing the molecular weight of nylon 6 carpet fibers according to claim 1, characterized in that, Step S1 is further refined as follows: S11. Prepare an appropriate amount of clean water and detergent, soak the waste nylon 6 carpet fibers in the detergent solution, and stir well. S12. Use a brush or mechanical equipment to clean the fibers to ensure that all dirt and impurities are removed; S13. Place the washed fibers in a dry area to air dry naturally or use a drying device to dry them. S14. Use a shredder to shred the dried fibers to ensure that the fiber fragments are of appropriate size for subsequent processing.

3. The method for increasing the molecular weight of nylon 6 carpet fibers according to claim 1, characterized in that, Step S2 is further refined as follows: S21. In the laboratory, accurately weigh organic or inorganic acids to prepare 0.1%-1% acid solutions. S22. Distribute the waste nylon 6 carpet fibers evenly in the acid solution, ensuring that all fibers come into contact with the acid solution; S23. Heat the acid solution to 70-100℃ and maintain this temperature for 30-60 minutes; S24. Stir the solution regularly to ensure uniform cationization treatment of the fibers.

4. The method for increasing the molecular weight of nylon 6 carpet fibers according to claim 1, characterized in that, Step S3 is further refined as follows: S31. Accurately weigh benzyl alcohol and formic acid, and prepare a solution at a ratio of 1:10-20. S32. Remove the cationized fiber from the acid solution and rinse it gently with water to remove excess acid; S33. Place the rinsed fibers into the prepared benzyl alcohol and formic acid solution to ensure that the fibers are completely soaked; S34. Heat the swollen solution to 50-100℃ and maintain this temperature for 1-1.5 hours, stirring the solution periodically during this period.

5. The method for increasing the molecular weight of nylon 6 carpet fibers according to claim 1, characterized in that, Step S4 is further refined as follows: S41. Prepare a solution of benzyl alcohol and formic acid in proportion, ensuring that the solution is mixed evenly; S42. Accurately weigh glutaraldehyde and prepare a glutaraldehyde solution of a certain concentration. S43. Gradually add the glutaraldehyde solution to the benzyl alcohol and formic acid solutions, stirring until well mixed; S44. Ensure that the reaction medium solution is in a uniform and stable state before use.

6. The method for increasing the molecular weight of nylon 6 carpet fibers according to claim 1, characterized in that, Step S5 is further refined as follows: S51. Remove the swollen nylon 6 fibers from the swelling solution and gently remove excess solution. S52. Place the fibers into the prepared reaction medium, ensuring that the fibers are evenly distributed; S53. Add glutaraldehyde solution to the reaction medium at a molar ratio of 1:1 to 1:8 and stir until homogeneous; S54. Heat the reaction medium to 100-120℃ and maintain the reaction time for 1-3 hours. Stir the solution regularly during the process to ensure that the reaction proceeds fully.

7. The method for increasing the molecular weight of nylon 6 carpet fibers according to claim 1, characterized in that, Step S6 is further refined as follows: S61. After the reaction is complete, remove the fiber from the reaction medium and gently remove any excess solution. S62. Wash the fibers multiple times with plenty of pure water to remove residual reactants and byproducts. S63. Place the washed fibers in a dry area to air dry naturally or use a drying device for drying. S64. Inspect the dried fibers to ensure there is no residual moisture or impurities.

8. The method for increasing the molecular weight of nylon 6 carpet fibers according to claim 1, characterized in that, Step S7 is further refined as follows: S71. Use gel permeation chromatography to test the change in molecular weight of fibers before and after treatment; S72. Use a tensile testing machine to test the tensile strength and elongation at break of the fiber; S73. Conduct abrasion resistance tests to evaluate the fiber's performance under abrasion conditions; S74. Conduct a dyeing test to check the dyeing uniformity and color fastness of the fibers.

9. The method for increasing the molecular weight of nylon 6 carpet fibers according to claim 1, characterized in that, Step S8 is further refined as follows: S81. The treated nylon 6 fiber was sent to a textile factory for actual production testing to observe the fiber’s performance in the textile process. S82. Collect and analyze data on the application of recycled nylon 6 fiber in different textile products; S83. Evaluate the cost-effectiveness of the processing technology, including material costs, energy consumption, and production efficiency; S84. Based on the test data, propose improvement suggestions to provide data support and process optimization solutions for large-scale production.

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