Dyeing method for improving ultraviolet resistance of mulberry silk fabric

Abstract

The invention relates to the technical field of textile engineering, and discloses a dyeing method for improving the ultraviolet resistance of a mulberry silk fabric, which comprises the following steps: S1, fabric pretreatment: washing the mulberry silk fabric by using an environment-friendly cleaning agent, removing impurities, and adopting a low-temperature enzyme treatment process; s2, preparing a bio-based nano material: extracting the bio-based nano material from chitosan, and modifying the bio-based nano material into an ultraviolet absorption type; s3, mixing the nano material with the dye, uniformly dispersing the modified bio-based nano material into the natural dye, and adding a proper amount of cross-linking agent; s4, a dyeing process: carrying out dip dyeing at a low temperature and a neutral pH value, and utilizing the high specific surface area and the adsorption capacity of the bio-based nano material; and S5, after-finishing. By reducing the UV transmittance to be lower than 5% and through the synergistic effect of the chitosan nano-material and the flavonoid anti-ultraviolet factors, UVA (320-400 nm) and UVB (280-320 nm) are effectively blocked, so that the skin is protected from being directly injured by ultraviolet rays.

Description

Technical Field

[0001] The present invention relates to the technical field of textile engineering, and specifically to a dyeing method for improving the ultraviolet resistance of mulberry silk fabrics. Background Art

[0002] As a natural fiber, mulberry silk is widely used in high-end clothing and home textile fields due to its unique luster, soft handfeel, and good air permeability. However, mulberry silk fibers are prone to photoaging under ultraviolet irradiation, and their protein structure (mainly silk protein) will gradually degrade due to ultraviolet-induced oxidation, resulting in a decrease in the mechanical properties, color fading, and strength of the fabric, thus seriously affecting the service life and appearance quality of the fabric. Therefore, how to improve the ultraviolet resistance of mulberry silk fabrics has become an important research direction in the development of functional textiles.

[0003] In traditional ultraviolet resistance technologies, although chemical ultraviolet absorbers and inorganic nanomaterials (such as titanium dioxide and zinc oxide) can provide a certain degree of ultraviolet shielding ability, the ultraviolet blocking efficiency is still limited in practical applications. Chemical ultraviolet absorbers mainly achieve the anti-ultraviolet effect by absorbing ultraviolet light and converting it into heat energy or other forms of energy. However, the absorption range of the absorber is usually limited to a specific wavelength band and it is difficult to cover both UVA (320 - 400 nm) and UVB (280 - 320 nm) simultaneously, resulting in a weak overall shielding effect. Although inorganic nanomaterials can reflect or scatter ultraviolet light, their shielding ability is limited by the particle size and dispersion uniformity, and the actual ultraviolet blocking rate usually fails to reach the high-efficiency standard. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a dyeing method for improving the ultraviolet resistance of mulberry silk fabrics, which solves the problem that although traditional ultraviolet resistance technologies can provide a certain degree of ultraviolet shielding ability, the ultraviolet blocking efficiency is still limited in practical applications.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A dyeing method for improving the ultraviolet resistance of mulberry silk fabrics, comprising the following steps:

[0006] S1. Fabric pretreatment

[0007] Wash the mulberry silk fabric with an environmentally friendly cleaning agent to remove impurities, and adopt a low-temperature enzyme treatment process;

[0008] S2. Preparation of bio-based nanomaterials

[0009] Extract bio-based nanomaterials from chitosan and modify the bio-based nanomaterials into ultraviolet absorbers;

[0010] S3. Mixing of nanomaterials and dyes

[0011] Uniformly disperse the modified bio-based nanomaterials into the natural dye, and add an appropriate amount of cross-linking agent;

[0012] S4. Dyeing process

[0013] Carry out impregnation dyeing at low temperature and neutral pH value. Utilize the high specific surface area and adsorption capacity of the bio-based nanomaterials to make the dye and anti-ultraviolet factors evenly distributed;

[0014] S5. Post-treatment

[0015] Carry out fixation treatment with an environmentally friendly fixing agent and add a softening finishing agent.

[0016] Preferably, in the S1 step, immerse the mulberry silk fabric in deionized water at 25 - 35 °C, add an appropriate amount of detergent, with the fabric mass: liquid volume ratio of 1:30 - 1:50, keep gently stirring for 15 - 25 minutes to dissolve the dirt and sizing on the fabric surface, and then rinse with deionized water 2 - 3 times until the fabric is clean without residual foam.

[0017] Preferably, in the S1 step, add protease to deionized water, adjust the pH value to 6.5 - 7.5, control the temperature at 25 - 30 °C, immerse the fabric in the enzyme solution for 10 - 20 minutes, gently stir, and rinse with clean water to remove the residual enzyme solution.

[0018] Preferably, in the S2 step, dissolve chitosan in a 1% acetic acid solution, stir for 2 - 3 hours until completely transparent, process it 3 - 5 times through a high-pressure homogenization device with a pressure of 15 - 25 MPa to obtain a nano-chitosan solution with uniform particle size, and use a dynamic light scattering instrument to detect the particle size of the nanoparticles, with the target range of 50 - 150 nm.

[0019] Preferably, in the S2 step, add a tea polyphenol solution to the nano-chitosan solution, with the mass ratio of chitosan: tea polyphenol = 10:1, heat to 40 - 50 °C, stir and react for 30 - 60 minutes, then cool to room temperature, and then carry out centrifugal separation to remove the unreacted substances and collect the modified nanoparticles.

[0020] Preferably, in the S3 step, dissolve the natural dye powder in deionized water according to a 10% mass ratio, add a dispersant and carry out ultrasonic treatment at 30 - 50 kHz for 10 - 15 minutes.

[0021] Preferably, in the S3 step, dropwise add the nano-chitosan solution into the dye solution, with the mass ratio of nanomaterial: dye = 1:8 - 1:12; finally, stir with a magnetic stirrer at room temperature for 30 - 40 minutes to obtain a composite dye solution.

[0022] Preferably, in the step S4, the dyeing conditions are set as follows: the ratio of fabric to dye liquor is 1:40 - 1:50, the pH value of the dye liquor is adjusted to 6.0 - 7.0 with acetic acid buffer solution; the dyeing temperature is controlled at 40 - 50 °C, and the impregnation time is 25 - 35 minutes.

[0023] Preferably, in the step S4, the pre-treated mulberry silk fabric is put into the dye liquor, and gently stirred to make the fabric evenly adsorb the dye liquor. The pH value is sampled and detected every 5 - 10 minutes. After the dyeing is completed, the fabric is taken out and rinsed with deionized water until the rinsing water is colorless.

[0024] Preferably, in the step S5, the fabric is impregnated in the fixing agent solution, the temperature is maintained at 30 - 40 °C for 10 - 15 minutes, rinsed to remove the unfixed fixing agent, and dried at a low temperature ≤ 40 °C;

[0025] The softener is dissolved in the rinsing solution, the fabric is soaked for 5 - 10 minutes, and the fabric is gently arranged after drying to restore softness.

[0026] The present invention provides a dyeing method for improving the ultraviolet resistance of mulberry silk fabric. It has the following beneficial effects:

[0027] 1. By reducing the UV transmittance to less than 5%, and through the synergistic effect of chitosan nanomaterials and flavonoid anti-ultraviolet factors, the present invention effectively blocks UVA (320 - 400 nm) and UVB (280 - 320 nm), thus protecting the skin from direct ultraviolet damage.

[0028] 2. The present invention uses chitosan, plant dyes and flavonoid extracts as core materials, and all raw materials are derived from natural or renewable resources. The use of such natural materials reduces the environmental pollution of traditional chemical dyeing processes, especially in the process of treating dyeing waste liquid, avoiding the emission of heavy metals and harmful chemicals. At the same time, the acetic acid required for dyeing is a low-toxic and environmentally friendly solvent, which can be easily neutralized after dyeing and does not cause secondary pollution to the environment. The whole process reduces the dependence on petrochemical-based chemicals and conforms to the industrial trend of sustainable development.

[0029] 3. In addition to the remarkable ultraviolet resistance performance, this method endows mulberry silk fabrics with multiple functions, including antibacterial, antioxidant, and soft breathability. Chitosan nanomaterials themselves have excellent antibacterial properties and can inhibit the growth of common bacteria (such as Staphylococcus aureus and Escherichia coli), with an antibacterial rate of over 90%. This enables the fabric to be applied not only to ordinary clothing but also in medical textiles and environments with high hygiene standards. In addition, the combination of chitosan and flavonoids enhances the antioxidant performance of the fabric, delays the aging of the fabric, and further increases its service life. Meanwhile, this method can enhance functionality without affecting the natural luster and softness of silk, enabling the fabric to remain comfortable and breathable in high-temperature and humid environments. Description of the Drawings

[0030] Figure 1 It is a process flow diagram of the dyeing method for improving the ultraviolet resistance of mulberry silk fabrics of the present invention. Detailed Embodiments

[0031] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] Please refer to the attached Figure 1 , the embodiment of the present invention provides a dyeing method for improving the ultraviolet resistance of mulberry silk fabrics, including the following steps:

[0033] S1. Fabric pretreatment

[0034] Wash the mulberry silk fabric with an environmentally friendly cleaner to remove impurities, and adopt a low-temperature enzyme treatment process;

[0035] S2. Preparation of bio-based nanomaterials

[0036] Extract bio-based nanomaterials from chitosan and modify the bio-based nanomaterials into ultraviolet absorbers;

[0037] S3. Mixing of nanomaterials and dyes

[0038] Uniformly disperse the modified bio-based nanomaterials into natural dyes and add an appropriate amount of cross-linking agent;

[0039] S4. Dyeing process

[0040] Perform impregnation dyeing at low temperature and neutral pH value, and utilize the high specific surface area and adsorption capacity of bio-based nanomaterials to make the dyes and ultraviolet resistance factors uniformly distributed;

[0041] S5. Post-treatment

[0042] Use an environmentally friendly fixing agent for fixing treatment and add a softening finishing agent.

[0043] Specifically, this method significantly improves the ultraviolet resistance of mulberry silk fabrics, reducing their UV transmittance to less than 5%. Through the synergistic effect of chitosan nanomaterials and flavonoid anti-ultraviolet factors, it effectively blocks UVA (320 - 400 nm) and UVB (280 - 320 nm), thus protecting the skin from direct ultraviolet damage. Compared with traditional anti-ultraviolet treatment methods, this method has higher efficiency and durability. It not only avoids the possible toxicity of ultraviolet absorbers to the human body but also greatly improves the practical value of the fabric. Especially in summer sun-protective clothing, outdoor sports clothing, and children's clothing, this anti-ultraviolet fabric can provide stronger protection for the wearer.

[0044] In step S1, immerse the mulberry silk fabric in deionized water at 25 - 35 °C, add an appropriate amount of detergent, with the fabric mass: liquid volume ratio of 1:30 - 1:50, keep gently stirring for 15 - 25 minutes to dissolve the dirt and sizing on the fabric surface, and then rinse with deionized water 2 - 3 times until the fabric is clean without residual foam.

[0045] Specifically, for the neutral detergent: Use a neutral detergent (1 - 2 g / L), such as an environmentally friendly cleaner derived from chitosan or a commercially available low-foam detergent. These detergents effectively remove dust, oil stains, and sizing on the surface of mulberry silk through mild cleaning action without damaging the natural protein structure of the silk, thus avoiding the hardening or weakening of silk fibers.

[0046] For deionized water: Use deionized water instead of ordinary water to avoid the damage of calcium and magnesium ions in the water to the silk and improve the adsorption uniformity of subsequent dyes.

[0047] Beneficial effects:

[0048] Thoroughly clean the fabric surface to ensure that the dye can adhere evenly to the fibers during dyeing.

[0049] Deionized water protects the fibers from mineral contamination, avoids problems such as uneven dyeing and spotting, and improves the quality of the finished product.

[0050] In step S1, add protease to deionized water, adjust the pH value to 6.5 - 7.5, control the temperature at 25 - 30 °C, immerse the fabric in the enzyme solution for 10 - 20 minutes, stir gently, and rinse with clean water to remove the residual enzyme solution.

[0051] Specifically, protease: Select a low-temperature active protease (0.5% - 1.5%) derived from Bacillus subtilis or fungi, which has the ability to gently decompose the residual proteins on the surface of mulberry silk. It has the best activity under mild conditions of 25 - 30°C, does not damage the main components (fibroin) of mulberry silk, and can maintain its natural luster and softness.

[0052] Deionized water: Once again, use deionized water as the solvent to provide a pure reaction environment and avoid the inhibition of enzyme activity by metal ions.

[0053] Beneficial effects:

[0054] Remove tiny impurities on the fabric surface, improve the hydrophilicity of the fiber surface, and create conditions for subsequent dye attachment.

[0055] Perform pretreatment under low-temperature conditions, reduce energy consumption, and at the same time avoid damage to silk fibers at high temperatures, maintaining their flexibility and natural luster.

[0056] In step S2, dissolve chitosan in a 1% acetic acid solution, stir for 2 - 3 hours until completely transparent, and process it 3 - 5 times through a high-pressure homogenization device with a pressure of 15 - 25 MPa to obtain a nano-chitosan solution with uniform particle size. Use a dynamic light scattering instrument to detect the particle size of the nanoparticles, and the target range is 50 - 150 nm.

[0057] Specifically, chitosan: A natural polysaccharide derived from aquatic waste such as shrimp shells and crab shells. Chitosan is a renewable resource, has good biocompatibility and biodegradability, and at the same time exhibits various excellent properties such as antibacterial, anti-corrosion, and anti-ultraviolet in the fiber treatment process.

[0058] Acetic acid: Use low-concentration (0.5% - 1%) acetic acid to dissolve chitosan to form a transparent and stable solution. Acetic acid is an environmentally friendly weak acid solvent, has no pollution to the environment, and is easy for subsequent neutralization treatment.

[0059] Beneficial effects:

[0060] Chitosan significantly increases the specific surface area through nano-sizing (particle size 50 - 150 nm), enabling it to form a uniform coating on the fabric surface.

[0061] The antibacterial property of chitosan can provide additional functionality for the fabric, such as inhibiting bacterial growth and increasing the hygienic performance of the fabric.

[0062] In step S2, add a tea polyphenol solution to the nano-chitosan solution, according to the mass ratio of chitosan:tea polyphenol = 10:1, heat to 40 - 50°C, stir and react for 30 - 60 minutes, then cool to room temperature, and then perform centrifugal separation to remove unreacted substances and collect the modified nanoparticles.

[0063] Specifically, flavonoid extracts: natural antioxidants such as tea polyphenols and onion flavonoids. Flavonoids can not only effectively absorb ultraviolet light (UVA and UVB bands), but also have excellent antioxidant capacity, which can delay the aging of fibers.

[0064] Deionized water: Ensure the purity of the solution during the preparation process to avoid impurities interfering with the attachment of flavonoid molecules and the stability of nanomaterials.

[0065] Beneficial effects:

[0066] By loading flavonoid extracts on the surface of chitosan, the UV resistance of nanoparticles is greatly improved, and the durability of fabrics is enhanced.

[0067] Using natural antioxidants can avoid the potential toxicity of traditional chemical UV absorbers to humans and the environment, and achieve green functional processing.

[0068] In step S3, dissolve the natural dye powder in deionized water at a mass ratio of 10%, add a dispersant, and perform ultrasonic treatment at 30 - 50 kHz for 10 - 15 minutes.

[0069] Specifically, plant dyes: plant dyes from natural sources such as mulberry red pigment, purple sweet potato pigment, and gardenia yellow pigment are used. These dyes are not only environmentally friendly, but also can endow fabrics with unique bright colors, while reducing the use of chemically synthesized dyes.

[0070] Dispersant: Water-soluble dispersants such as polyethylene glycol (0.5% - 1%) are used to improve the dispersion of natural dyes and prevent particles from aggregating or precipitating in the solution.

[0071] Beneficial effects:

[0072] The use of natural dyes reduces the environmental burden of textile dyeing processes and provides consumers with healthy and safe dyed fabrics.

[0073] The dispersant ensures the uniform distribution of dye particles, making the dyeing effect more stable and uniform.

[0074] In step S3, add the nano-chitosan solution dropwise to the dye solution at a mass ratio of nanomaterial:dye = 1:8 - 1:12; finally, stir with a magnetic stirrer at room temperature for 30 - 40 minutes to obtain a composite dye solution.

[0075] Specifically, chitosan nanomaterials: Mix with dyes in a ratio (nanomaterial:dye = 1:8 - 1:12) to form a composite dye solution. Chitosan nanomaterials can be used as a fixed carrier for natural dyes to improve the fastness after dyeing.

[0076] Beneficial effects:

[0077] The composite of chitosan nanomaterials and natural dyes not only enhances the UV resistance of the dye solution but also ensures the uniform distribution of the dyes on the fabric.

[0078] The composite dye solution has higher stability, reducing the phenomena of stratification or precipitation during the dyeing process.

[0079] In step S4, the dyeing conditions are set as follows: the ratio of fabric to dye solution is 1:40 - 1:50, the pH value of the dye solution is adjusted to 6.0 - 7.0 with acetic acid buffer solution; the dyeing temperature is controlled at 40 - 50 °C, and the impregnation time is 25 - 35 minutes.

[0080] In step S4, the pretreated mulberry silk fabric is put into the dye solution, and gently stirred to make the fabric uniformly adsorb the dye solution. The pH value is sampled and detected every 5 - 10 minutes. After the dyeing is completed, the fabric is taken out and rinsed with deionized water until the rinsing water is colorless.

[0081] Specifically, for the dye solution regulator: acetic acid is used to adjust the pH value to 6.0 - 7.0 to ensure that the dyeing environment is close to neutral and protect the silk fibers from being damaged.

[0082] Beneficial effects:

[0083] Dyeing under low temperature (40 - 50 °C) and neutral conditions maximally protects the softness and luster of the silk and ensures that the fiber strength does not decrease.

[0084] The dyeing process is completed in a short time (25 - 35 minutes), reducing energy consumption and improving efficiency.

[0085] In step S5, the fabric is impregnated in the fixing agent solution, maintaining the temperature at 30 - 40 °C for 10 - 15 minutes, rinsed to remove the unfixed fixing agent, and dried at a low temperature ≤ 40 °C;

[0086] The softener is dissolved in the rinsing solution, and the fabric is soaked for 5 - 10 minutes. After drying, the fabric is gently arranged to restore its softness.

[0087] Specifically, for the fixing agent: an environmentally friendly polyacrylate-based fixing agent (2% - 4%), which forms a stable bond with the dye molecules to improve the wash fastness of the fabric.

[0088] Beneficial effects:

[0089] The use of the fixing agent significantly enhances the durability of the dyed fabric and reduces the color fading problem during subsequent wearing and washing.

[0090] Coconut oil-based softener: extracted from natural coconut oil, containing long-chain fatty acids, which can penetrate into the fiber interior to improve the softness and handle of the fabric.

[0091] Beneficial effects:

[0092] Through the treatment with softener, the fabric is more comfortable while not affecting its breathability and functionality.

[0093] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A dyeing method for improving the ultraviolet resistance of mulberry silk fabrics, characterized in that: The following steps are involved: S1. Fabric pretreatment Silk fabrics are washed using environmentally friendly detergents to remove impurities and treated with low-temperature enzymes; S2. Preparation of bio-based nanomaterials Extracting bio-based nanomaterials from chitosan and modifying bio-based nanomaterials into UV absorbers; S3. Mixing of nanomaterials and dyes The modified bio-based nanomaterials are uniformly dispersed in the natural dye and an appropriate amount of a cross-linking agent is added; S4. Dyeing process Dip dyeing is carried out at low temperature and neutral pH, using the high specific surface area and adsorption capacity of bio-based nanomaterials to evenly distribute the dye and UV-resistant factors; S5, finishing Environmentally friendly color fixing agent is used for color fixing treatment, and softening finishing agent is added.

2. The dyeing method for improving the ultraviolet resistance of mulberry silk fabric according to claim 1, characterized in that: In the step S1, the silk fabric is immersed in deionized water at 25-35° C., an appropriate amount of detergent is added, and the ratio of fabric mass to liquid volume is 1:30-1:

50. The fabric is gently stirred for 15-25 minutes to dissolve the dirt and slurry on the surface of the fabric, and then rinsed with deionized water for 2-3 times until the fabric is clean and no residual foam is left.

3. The dyeing method for improving the anti-ultraviolet ability of mulberry silk fabric according to claim 1, characterized in that: In the step S1, protease is added to deionized water, the pH value is adjusted to 6.5-7.5, the temperature is controlled at 25-30° C., the fabric is immersed in the enzyme solution for 10-20 minutes, gently stirred, and rinsed with clean water to remove the enzyme solution residue.

4. The dyeing method for improving the ultraviolet resistance of mulberry silk fabric according to claim 1, characterized in that: In the step S2, chitosan is dissolved in a 1% acetic acid solution, stirred for 2 to 3 hours until completely transparent, and processed 3 to 5 times by a high-pressure homogenizer at a pressure of 15 to 25 MPa to obtain a nano-chitosan solution with uniform particle size. The particle size of the nanoparticles is detected using a dynamic light scattering instrument, and the target range is 50 to 150 nm.

5. The dyeing method for improving the ultraviolet resistance of mulberry silk fabric according to claim 1, characterized in that: In the step S2, tea polyphenol solution is added to the nano-chitosan solution, and the solution is heated to 40-50° C. at a mass ratio of chitosan: tea polyphenol=10:1, stirred for reaction for 30-60 minutes, then cooled to room temperature, centrifuged to remove unreacted substances, and the modified nanoparticles are collected.

6. The dyeing method for improving the ultraviolet resistance of mulberry silk fabric according to claim 1, characterized in that: In the step S3, the natural dye powder is dissolved in deionized water at a mass ratio of 10%, a dispersant is added, and ultrasonic treatment is performed at 30 to 50 kHz for 10 to 15 minutes.

7. The dyeing method for improving the ultraviolet resistance of mulberry silk fabric according to claim 1, characterized in that: In the step S3, the nano-chitosan solution is added dropwise into the dye solution, with the mass ratio of nano-material: dye being 1:8 to 1:12; and finally, the mixture is stirred at room temperature for 30 to 40 minutes using a magnetic stirrer to obtain a composite dye solution.

8. The dyeing method for improving the ultraviolet resistance of mulberry silk fabric according to claim 1, characterized in that: In the step S4, the dyeing conditions are set as fabric: dye liquor is 1:40-1:50, the pH value of the dye liquor is adjusted to 6.0-7.0 with acetate buffer; the dyeing temperature is controlled at 40-50° C., and the immersion dyeing time is 25-35 minutes.

9. The dyeing method for improving the ultraviolet resistance of mulberry silk fabric according to claim 1, characterized in that: In the step S4, the pre-treated mulberry silk fabric is placed in the dye solution and gently stirred to allow the fabric to evenly absorb the dye solution. Samples are taken every 5 to 10 minutes to detect the pH value. After dyeing is completed, the fabric is taken out and rinsed with deionized water until the water is colorless.

10. The dyeing method for improving the ultraviolet resistance of mulberry silk fabric according to claim 1, characterized in that: In the step S5, the fabric is immersed in a color fixing agent solution, maintained at a temperature of 30 to 40° C. for 10 to 15 minutes, rinsed to remove unabsorbed color fixing agent, and dried at a low temperature of ≤40° C.; Dissolve the softener in the rinse liquid, soak the fabric for 5 to 10 minutes, and gently adjust the fabric after drying to restore its softness.

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