A method for enzyme refining of cotton and cellulose biofiber blends

Abstract

This application relates to the field of enzymatic refining technology for textiles, specifically a method for enzymatic refining of a cotton-cellulose bio-fiber blend, comprising the following steps: S1, immersing the cotton-cellulose bio-fiber blended fabric in an α-amylase solution for treatment, followed by rinsing, dehydration, and drying; S2, immersing the fabric obtained in step S1 in a working solution for treatment, removing, washing, dehydrating, and drying; the working solution comprises aminated mesoporous silica-immobilized pectinase and fatty alcohol polyoxyethylene ether; S3, immersing the fabric obtained in step S2 in a chitosan quaternary ammonium salt solution for impregnation treatment, followed by pre-drying; then immersing in an oxidized tannic acid solution for impregnation treatment and drying, followed by washing and drying. The blended fabric treated by this method exhibits a total impurity removal rate ≥91%, a breaking strength retention rate ≥92%, a fibrillation index ≤0.9, and a colorfastness ≥68%.

Description

Technical Field

[0001] This application relates to the field of enzymatic refining technology for textiles, and in particular to an enzymatic refining method for cotton and cellulose bio-fiber blends. Background Technology

[0002] Blended fabrics of cotton and cellulosic bio-fibers (such as viscose, lyocell, and modal) are widely used in the textile industry due to their combination of the comfort of cotton and the excellent properties of regenerated cellulose fibers. However, these blended fabrics require refining before dyeing and finishing to remove natural impurities such as pectin and waxes. Although traditional alkaline refining processes can effectively remove impurities, they suffer from problems such as high energy consumption, high alkalinity in wastewater, and severe fiber damage. Furthermore, strong alkaline conditions can easily cause severe swelling and fibrillation of cellulosic bio-fibers, seriously affecting fabric quality.

[0003] Enzymatic refining technology has become a research hotspot due to its advantages such as mild reaction conditions, high specificity, and environmental friendliness. However, free pectinase has drawbacks such as poor stability, easy inactivation, difficulty in recycling, and potential excessive degradation of fibers. In addition, cellulose biofibers have smooth surfaces and low crystallinity, making them prone to fibrillation during wet processing, resulting in pilling, rough hand feel, and reduced fiber strength. At the same time, blended fabrics have increased surface negative charge after enzymatic refining, reducing their affinity for anionic dyes and making it difficult to meet production requirements for color fixation.

[0004] In existing technologies, there is a lack of solutions for the enzymatic refining of cotton and cellulose bio-fiber blended fabrics that can simultaneously achieve high-efficiency refining, low fiber damage, antigen fibrillation, and high color fastness. Therefore, developing an enzymatic refining method that can synergistically solve the above problems is of significant practical importance for improving the processing quality of blended fabrics. Summary of the Invention

[0005] This invention provides an enzyme refining method for blended cotton and cellulose bio-fiber fabrics. The blended fabrics treated by this method have a high fiber strength retention rate, a low fibrillation index, and improved colorfastness.

[0006] In a first aspect of this application, an enzymatic refining method is provided for a cotton and cellulose bio-fiber blend, comprising the following steps: S1, immersing the cotton and cellulose bio-fiber blended fabric in an α-amylase solution for treatment, rinsing, dehydrating, and drying; S2, immersing the fabric obtained in step S1 in a working solution for treatment, removing, washing, dehydrating, and drying; the working solution comprises aminated mesoporous silica immobilized pectinase and fatty alcohol polyoxyethylene ether; S3, immersing the fabric obtained in step S2 in a chitosan quaternary ammonium salt solution for impregnation treatment, pre-drying; then immersing in an oxidized tannic acid solution for impregnation treatment and drying, washing, and drying.

[0007] By adopting the above technical solution, this application provides an enzymatic refining treatment method for cotton and cellulose bio-fiber blends. The blended fabric treated by this method has a total impurity removal rate of ≥91%, a breaking strength retention rate of ≥92%, a fibrillation index of ≤0.9, and a color fixation rate of ≥68%. This may be because the aminated mesoporous silica immobilized pectinase in the working solution efficiently removes natural impurities such as pectin under mild conditions. The mesoporous carrier not only improves the stability of the enzyme but also restricts the free diffusion of enzyme molecules through spatial confinement effect, avoiding excessive damage to the fiber structure by free enzymes and effectively protecting the fiber strength. At the same time, chitosan quaternary ammonium salt, as a cationic polymer, can be uniformly adsorbed on the negatively charged fiber surface, while the tannic acid oxidized by sodium periodate can undergo a Schiff base reaction with the amino groups of chitosan quaternary ammonium salt to form an imine bond cross-linking network. This cross-linking process forms a tough, mesh-like protective film on the surface of the blended fibers. It not only effectively locks in surface microfibers and significantly inhibits fibrillation during wet processing, but also greatly enhances the fabric's affinity for anionic dyes (such as reactive dyes) by introducing a large number of cationic groups, thereby synergistically achieving high breaking strength retention and high color fastness.

[0008] Optionally, in step S2, the working solution includes aminated mesoporous silica-immobilized pectinase at a mass concentration of 1.4-1.6 g / L and fatty alcohol polyoxyethylene ether at a mass concentration of 2.0-2.4 g / L.

[0009] Optionally, the fatty alcohol polyoxyethylene ether is a fatty alcohol polyoxyethylene ether C12-C14, and its ethylene oxide addition number EO is 10-15.

[0010] Optionally, in the working solution of step S2, the method for preparing aminated mesoporous silica-immobilized pectinase includes the following steps: a1. Disperse SBA-15 in toluene, add 3-aminopropyltriethoxysilane, reflux; centrifuge, wash, and dry to obtain NH2-SBA-15; a2. Disperse the NH2-SBA-15 obtained in step a1 in a buffer solution, add glutaraldehyde, shake, centrifuge, and wash to obtain the activated carrier. a3. Disperse the activated carrier obtained in step a2 in a buffer solution, add pectinase, shake at low temperature, add more pectinase, shake at room temperature, add NaBH4 solution, react, centrifuge, wash, and dry to obtain aminated mesoporous silica immobilized pectinase.

[0011] Optionally, in step a3, the mass ratio of the activated carrier to total pectinase is 20:(3-5).

[0012] Optionally, in step a3, the mass ratio of pectinase added by shaking at low temperature to pectinase added by shaking at room temperature is (3-4):1.

[0013] Optionally, in step S3, the mass concentration of chitosan quaternary ammonium salt is 1.1-1.3 g / L, and the mass concentration of oxidized tannic acid is 0.2-0.4 g / L.

[0014] Optionally, in step S3, the mass concentration ratio of chitosan quaternary ammonium salt to oxidized tannic acid is (2.75-6.5):1.

[0015] By adopting the above technical solution and adjusting the amount of chitosan quaternary ammonium salt and oxidized tannic acid according to the above mass concentration ratio, the mass concentration ratio of chitosan quaternary ammonium salt to oxidized tannic acid is (2.75-6.5):1. The treated blended fabric can have a better breaking strength retention rate and color fixation rate, and a smaller fibrillation index.

[0016] Optionally, in step S1, the mass concentration of α-amylase is 0.3-1.0 g / L, the pH of the treatment is 6.5-7.0, the treatment temperature is 42-48℃, and the treatment time is 15-25 min.

[0017] Optionally, in step S2, the pH of the treatment is 6.2-6.8, the treatment temperature is 40-48℃, and the treatment time is 45-75 min.

[0018] Optionally, in step S3, the pH of the chitosan quaternary ammonium salt solution is 5.0-6.0, the immersion temperature is 35-45℃, and the immersion time is 15-25 min; the pH of the oxidized tannic acid solution is 5.0-5.5, the immersion temperature is 25-35℃, and the immersion time is 8-15 min.

[0019] Optionally, the cellulose biofiber is selected from at least one of viscose, lyocell, and modal.

[0020] Optionally, the blending ratio of cotton and viscose is (30-50):(50-70), the blending ratio of cotton and lyocell is (60-80):(20-40), and the blending ratio of cotton and modal is (45-65):(35-55).

[0021] Optionally, the chitosan quaternary ammonium salt is prepared by dispersing chitosan in a mixed solution of isopropanol and water, adding an aqueous solution of 2,3-epoxypropyltrimethylammonium chloride dropwise, heating under a protective gas, reacting, cooling, precipitating, washing, and drying to obtain the chitosan quaternary ammonium salt.

[0022] Optionally, the method for preparing the oxidized tannic acid is as follows: tannic acid is reacted with an equimolar amount of sodium periodate under light-protected conditions, and the reaction product is dialyzed to remove residual periodate ions, and then freeze-dried to obtain oxidized tannic acid.

[0023] In summary, the present invention has at least one of the following beneficial technical effects: 1. This application provides an enzymatic refining method for cotton and cellulose bio-fiber blends. This application uses aminated mesoporous silica to immobilize pectinase. With the help of the spatial protection of the carrier, pectin impurities are effectively removed while the fibrillation index of cellulose is controlled.

[0024] 2. This application provides an enzyme refining treatment method for cotton and cellulose bio-fiber blends. Through the sequential impregnation and cross-linking reaction of chitosan quaternary ammonium salt and oxidized tannic acid, a cationic cross-linking protective network is constructed on the surface of cellulose bio-fibers. This not only overcomes the fibrillation defects caused by mechanical friction, but also improves the dye repulsion problem caused by the increase of negative charge on the fabric surface after enzyme refining, thereby improving the fixation rate. Detailed Implementation

[0025] The embodiments of the present invention will be described in detail below with reference to the examples. However, those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention. Specific conditions not specified in the examples shall be carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0026] SBA-15 was purchased from Nanjing Xianfeng Nanomaterials Technology Co., Ltd. (100931), chitosan from Shanghai Maclean Biochemical Technology Co., Ltd. (C766421), pectinase from Shanghai Maclean Biotechnology Co., Ltd. (P758970), α-amylase from Shanghai Aladdin Biochemical Technology Co., Ltd. (A755211), fatty alcohol polyoxyethylene ether C12-C14 (EO=10) from Taiwan PanYa (PANNOX 710PH), fatty alcohol polyoxyethylene ether C12-C14 (EO=10.7) from Taiwan PanYa (PANNOX 712B), fatty alcohol polyoxyethylene ether C12-C14 (EO=15) from Taiwan PanYa (PANNOX 715), and tannic acid from Shaanxi Haochen Biotechnology Co., Ltd.

[0027] Preparation Example 1 Preparation of aminated mesoporous silica-immobilized pectinase (NH2-SBA-15-pectinase) a1. Disperse 1g of SBA-15 in 30mL of anhydrous toluene, add 0.5mL of 3-aminopropyltriethoxysilane (APTES), reflux at 110℃ for 12h, centrifuge, wash 3 times with anhydrous ethanol, and dry at 60℃ to obtain aminated SBA-15 (NH2-SBA-15). a2. Disperse 100 mg of NH2-SBA-15 obtained in step a1 in 5 mL of sodium phosphate buffer (100 mM, pH=6.5) by ultrasonication, add 0.1 mL of 25 (w / v)% glutaraldehyde aqueous solution, shake and react at 25 °C for 2 h, centrifuge, and wash 3 times with sodium phosphate buffer (100 mM, pH=6.5) to obtain the activated carrier; a3. Disperse 100 mg of the activated carrier obtained in step a2 in 5 mL of sodium phosphate buffer (100 mM, pH=6.5), add 15 mg of pectinase, shake at 4 °C for 2 h, add another 5 mg of pectinase, shake at 25 °C for 2 h, add 0.5 mL of NaBH4 aqueous solution with a concentration of 10 mg / mL, react at 25 °C for 30 min, centrifuge, wash 3 times with sodium phosphate buffer (100 mM, pH=6.5), dry to obtain aminated mesoporous silica immobilized pectinase (NH2-SBA-15-pectinase).

[0028] Preparation Example 2 Preparation of chitosan quaternary ammonium salt 10 g of chitosan was dispersed in 100 mL of a mixed solution consisting of isopropanol and deionized water in a 1:1 volume ratio. The mixture was stirred at room temperature for 30 min to obtain a homogeneous slurry. 3.84 g of 2,3-epoxypropyltrimethylammonium chloride (GTA) was weighed and dissolved in 20 mL of deionized water, then slowly added dropwise to the homogeneous slurry. The mixture was heated to 60 °C under N2 protection and stirred at 150 rpm for 4.5 h. After cooling to room temperature, 450 mL of anhydrous ethanol was added to precipitate the mixture. The precipitate was collected by centrifugation, washed three times with anhydrous ethanol, dried at 40 °C and 10 kPa for 24 h, and then pulverized through a 100-mesh sieve to obtain chitosan quaternary ammonium salt.

[0029] The NH2-SBA-15-pectinase used in the following examples and comparative examples were all derived from Preparation Example 1, and the chitosan quaternary ammonium salt used were all derived from Preparation Example 2.

[0030] Example 1

[0031] Example 1 provides an enzymatic refining method for a blend of cotton and cellulose bio-fibers, comprising the following steps: S1. Soak a cotton / viscose (blend ratio of 40:60), wherein the cotton fiber content is 40% and the viscose fiber content is 60%, in an aqueous solution containing 0.7 g / L α-amylase at a bath ratio of 1:20, adjust the pH to 6.7, treat at 45℃ for 20 min, then rinse twice with cold water for 5 min each time, centrifuge to dehydrate, and dry. S2. Immerse the fabric obtained in step S1 into the working solution at a bath ratio of 1:20. The working solution consists of 1.4 g / L of NH2-SBA-15-pectinase and 2.0 g / L of fatty alcohol polyoxyethylene ether C12-C14 (EO=10), with water as the solvent. Adjust the pH to 6.6 using a phosphate buffer system. Shake at 45°C for 60 min, remove and rinse with cold water for 10 min, then wash with hot water at 60°C for 2 min, centrifuge to remove water, and dry. S3. The fabric obtained in step S2 is immersed in a chitosan quaternary ammonium salt solution using a two-dip, two-nip method. The solvent is water, and the mass concentration of chitosan quaternary ammonium salt is 1.2 g / L. The pH is adjusted to 5.5 with 0.1 mol / L acetic acid solution. The fabric is immersed at 40°C for 20 min, with a roll-off rate of 88%. It is then pre-dried at 80°C for 2 min. After pre-drying, the fabric is naturally cooled to room temperature and then immersed in an oxidized tannic acid solution using a two-dip, two-nip method. The mass concentration of oxidized tannic acid is 0.3 g / L, and the solvent is water. The pH is adjusted to 5.3. The fabric is immersed at 30°C for 10 min, with a roll-off rate of 88%. The fabric is then washed with cold water and dried. The oxidized tannic acid is obtained by reacting tannic acid with an equimolar amount of sodium periodate at 4°C in the dark for 24 h, dialyzing through a dialysis bag (molecular weight cutoff 3500 Da) for 24 h to remove residual periodate, and then freeze-drying.

[0032] Example 2

[0033] Example 2 provides an enzymatic refining method for a blend of cotton and cellulose bio-fibers, comprising the following steps: S1. Immerse a cotton / lyocell (blended ratio of 70:30), wherein the cotton fiber content is 70% and the lyocell fiber content is 30%, in an aqueous solution containing 0.7 g / L α-amylase at a bath ratio of 1:20, adjust the pH to 6.7, treat at 45℃ for 20 min, then rinse twice with cold water for 5 min each time, centrifuge to dehydrate, and dry. S2. Immerse the fabric obtained in step S1 into the working solution at a liquor ratio of 1:20. The working solution consists of 1.6 g / L of NH2-SBA-15-pectinase and 2.4 g / L of fatty alcohol polyoxyethylene ether C12-C14 (EO=10.7), with water as the solvent. Adjust the pH to 6.7 using a phosphate buffer system. Shake at 45°C for 60 min, remove and rinse with cold water for 10 min, then wash with hot water at 60°C for 2 min, centrifuge to remove water, and dry. S3. The fabric obtained in step S2 is immersed in a chitosan quaternary ammonium salt solution using a two-dip, two-nip method. The solvent is water, and the mass concentration of chitosan quaternary ammonium salt is 1.2 g / L. The pH is adjusted to 5.5 with 0.1 mol / L acetic acid solution. The fabric is immersed at 40°C for 20 min, with a roll-off rate of 88%. It is then pre-dried at 80°C for 2 min. After pre-drying, the fabric is naturally cooled to room temperature and then immersed in an oxidized tannic acid solution using a two-dip, two-nip method. The mass concentration of oxidized tannic acid is 0.3 g / L, and the pH is adjusted to 5.3. The fabric is immersed at 30°C for 10 min, with a roll-off rate of 88%. The fabric is then washed with cold water and dried. The oxidized tannic acid is obtained by reacting tannic acid with an equimolar amount of sodium periodate at 4°C in the dark for 24 h, dialyzing through a dialysis bag (molecular weight cutoff 3500 Da) for 24 h to remove residual periodate, and then freeze-drying.

[0034] Example 3

[0035] Example 3 provides an enzymatic refining method for a blend of cotton and cellulose bio-fibers, comprising the following steps: S1. Soak a cotton / modal (blended ratio of 55:45), wherein the cotton fiber content is 55% and the modal fiber content is 45%, in an aqueous solution containing 0.7 g / L α-amylase at a bath ratio of 1:20, adjust the pH to 6.7, treat at 45℃ for 20 min, then rinse twice with cold water for 5 min each time, centrifuge to dehydrate, and dry. S2. Immerse the fabric obtained in step S1 into the working solution at a bath ratio of 1:20. The working solution consists of 1.4 g / L of NH2-SBA-15-pectinase and 2.2 g / L of fatty alcohol polyoxyethylene ether C12-C14 (EO=10.7), with water as the solvent. Adjust the pH to 6.6 using a phosphate buffer system. Shake at 45°C for 60 min, remove and rinse with cold water for 10 min, then wash with hot water at 60°C for 2 min, centrifuge to remove water, and dry. S3. The fabric obtained in step S2 is immersed in a chitosan quaternary ammonium salt solution using a two-dip, two-nip method. The solvent is water, and the mass concentration of chitosan quaternary ammonium salt is 1.2 g / L. The pH is adjusted to 5.5 with 0.1 mol / L acetic acid solution. The fabric is immersed at 40°C for 20 min, with a roll-off rate of 88%. It is then pre-dried at 80°C for 2 min. After pre-drying, the fabric is naturally cooled to room temperature and then immersed in an oxidized tannic acid solution using a two-dip, two-nip method. The mass concentration of oxidized tannic acid is 0.3 g / L, and the solvent is water. The pH is adjusted to 5.3. The fabric is immersed at 30°C for 10 min, with a roll-off rate of 88%. The fabric is then washed with cold water and dried. The oxidized tannic acid is obtained by reacting tannic acid with an equimolar amount of sodium periodate at 4°C in the dark for 24 h, dialyzing through a dialysis bag (molecular weight cutoff 3500 Da) for 24 h to remove residual periodate, and then freeze-drying.

[0036] Example 4

[0037] Example 4 provides an enzymatic refining method for cotton and cellulose bio-fiber blends. The difference from Example 3 is that in step S3, the total mass concentration of chitosan quaternary ammonium salt and oxidized tannic acid remains unchanged, and the mass concentration ratio of chitosan quaternary ammonium salt to oxidized tannic acid is 1.3:0.2.

[0038] The other preparation steps are the same as in Example 3.

[0039] Example 5

[0040] Example 5 provides an enzymatic refining method for cotton and cellulose bio-fiber blends. The difference from Example 3 is that in step S3, the total mass concentration of chitosan quaternary ammonium salt and oxidized tannic acid remains unchanged, and the mass concentration ratio of chitosan quaternary ammonium salt to oxidized tannic acid is 1.1:0.4.

[0041] The other preparation steps are the same as in Example 3.

[0042] Comparative Example 1 Comparative Example 1 provides an enzymatic refining method for a blend of cotton and cellulose bio-fibers. The difference from Example 3 is that in step S3, the fabric is not immersed in a chitosan quaternary ammonium salt solution.

[0043] Specifically, step S3 is different, and is as follows: S3, the fabric obtained in step S2 is immersed in an oxidized tannic acid solution by a two-dip and two-ply method. The mass concentration of oxidized tannic acid is 0.3 g / L, the solvent is water, the pH is adjusted to 5.3, the immersion treatment is carried out at 30°C for 10 min, the roll-off rate is 88%, the fabric is washed with cold water and dried; the oxidized tannic acid is obtained by reacting tannic acid with an equimolar amount of sodium periodate at 4°C in the dark for 24 h, dialyzing through a dialysis bag (molecular weight cutoff 3500 Da) for 24 h to remove residual periodate, and freeze-drying.

[0044] The other steps are the same as in Example 3.

[0045] Comparative Example 2 Comparative Example 2 provides an enzymatic refining method for a blend of cotton and cellulose bio-fibers. The difference from Example 3 is that in step S3, the fabric is not immersed in an oxidized tannic acid solution.

[0046] Specifically, step S3 is different, and is as follows: S3, the fabric obtained in step S2 is immersed in a chitosan quaternary ammonium salt solution by two dips and two nips. The solvent is water, the mass concentration of chitosan quaternary ammonium salt is 1.2 g / L, the pH is adjusted to 5.5 with 0.1 mol / L acetic acid solution, the immersion treatment is carried out at 40℃ for 20 min, the nip-off rate is 88%, and then it is dried.

[0047] The other steps are the same as in Example 3.

[0048] Comparative Example 3 Comparative Example 3 provides an enzymatic refining method for a blend of cotton and cellulose bio-fibers, which differs from Example 3 in that step S3 is omitted.

[0049] The other steps are the same as in Example 3.

[0050] Comparative Example 4 Comparative Example 4 provides an enzymatic refining method for cotton and cellulose bio-fiber blends. The difference from Example 3 is that in step S2, the mass concentration of NH2-SBA-15-pectinase in the working solution is replaced with SBA-15-pectinase.

[0051] Specifically, the preparation steps of SBA-15-pectinase are as follows: Disperse 100 mg of SBA-15 in 5 mL of sodium phosphate buffer (100 mM, pH=6.5), add 15 mg of pectinase, shake at 4 °C for 2 h, add another 5 mg of pectinase, shake at 25 °C for 2 h, centrifuge, wash 3 times with sodium phosphate buffer (100 mM, pH=6.5), and dry to obtain SBA-15-pectinase.

[0052] The other steps are the same as in Example 3.

[0053] Comparative Example 5 Comparative Example 5 provides an enzymatic refining method for a blend of cotton and cellulose bio-fibers. The difference from Example 3 is that in step S3, the mass concentration of oxidized tannins is replaced with tannins.

[0054] The other steps are the same as in Example 3.

[0055] Performance testing The fabrics obtained by the methods of Examples 1-5 and Comparative Examples 1-5 were conditioned for 24 hours in standard atmosphere at a temperature of (20±2)℃ and a relative humidity of (65±4)%, and then subjected to the following tests: Total impurity removal rate: Samples were taken after step S2 and determined by gravimetric method. Three fabric samples (20cm×20cm) were taken before and after scouring and dried at 105℃ to constant weight. Total impurity removal rate = [(dry weight before scouring - dry weight after scouring) / dry weight before scouring] × 100%; Tensile strength retention rate: Samples were taken after all processes were completed, and the tensile strength of the fabric before and after treatment was determined according to GB / T 3923.1-2013 (CRE tester, sample width 50mm, spacing 200mm, tensile speed 100mm / min, 5 samples each in the warp and weft directions). Retention rate = (strength after treatment / strength before treatment) × 100%; fibrillation index: After all processes are completed, samples are taken, and 10 weft filaments (each approximately 10 mm in length) are extracted from the fabric. The filaments are immersed in a 30 mL glass bottle containing 10 mL of distilled water and ultrasonically treated for 15 min in an ultrasonic cleaner (300 W, 40 kHz). During the ultrasonic treatment, the bottle is cooled with an ice-water bath. After ultrasonic treatment, the filaments are removed, placed on a glass slide, deionized water is added, a coverslip is placed, and the samples are observed under an optical microscope (400×). Image analysis software is used to measure the length L of each fiber trunk and the length l of each microfibril. i According to formula I f =∑l i / L calculates the fibrillation index (I) of a single fiber. f The arithmetic mean of the fibrillation indices of 10 fibers was taken as the fibrillation index of the sample. Fixation rate: Samples were taken after all processes were completed and determined using the reactive dye residual liquor method. Referring to GB / T 2391-2006, 2% (owf) of Reactive Red M-8B was used, with a liquor ratio of 1:20, 60 g / L of sodium sulfate, and 20 g / L of soda ash. Dyeing was carried out at 60℃ for 60 min. The absorbance of the dye liquor was measured before and after dyeing to calculate the dyeing rate. The absorbance of the residual liquor was measured after soaping to calculate the fixation rate. The results are shown in Table 1.

[0056] Table 1

[0057] Conclusion Analysis and Summary As can be seen from Examples 1-3 and Table 1, the enzyme refining process of this application can improve the total impurity removal rate, fiber strength retention rate, fibrillation index, and subsequent color fixation of cotton blended fabrics with viscose, lyocell, and modal.

[0058] Based on Examples 3, 4-5 and Table 1, it can be seen that adjusting the amount of chitosan quaternary ammonium salt and oxidized tannic acid in step S3 can affect the treatment effect on the fabric. In Example 3, when the mass concentration ratio of chitosan quaternary ammonium salt to oxidized tannic acid is 4:1, the final treatment effect on the fabric is better than that in Examples 4 and 5.

[0059] Based on Example 3, Comparative Examples 1-3 and Table 1, it can be seen that chitosan quaternary ammonium salt and oxidized tannic acid can work synergistically in step S3 to improve the fiber strength retention rate and color fixation rate of the fabric, and reduce the fibrillation index. In Comparative Example 1, the fabric was not immersed in the chitosan quaternary ammonium salt solution. In Comparative Example 2, the fabric was not immersed in the oxidized tannic acid solution. In Comparative Example 3, step S3 was omitted. The fiber strength retention rate and color fixation rate of the fabric decreased significantly, and the fibrillation index increased.

[0060] Based on Examples 3, Comparative Examples 4-5, and Table 1, it can be seen that in Comparative Example 4, replacing the mass concentration of NH2-SBA-15-pectinase with SBA-15-pectinase significantly reduced the total impurity removal rate, fiber strength retention rate, and color fixation rate of the fabric, while increasing the fibrillation index. In Comparative Example 5, replacing the mass concentration of oxidized tannic acid with tannic acid significantly reduced the fiber strength retention rate and color fixation rate of the fabric, while increasing the fibrillation index. This may be because, in Comparative Example 4, the unaminated SBA-15 lacks active amino groups on its surface, making it unable to form a stable covalent bond with pectinase via glutaraldehyde bridging. The enzyme molecules mainly rely on physical adsorption loading, and are easily detached and inactivated or released as free enzymes during the refining process. The interaction between free enzymes and fibers is uncontrollable, which may lead to over-refining, damaging the fiber surface structure and exposing microfibrils, making fibrillation more likely to occur during wet processing. In Comparative Example 5, although tannic acid can bind with chitosan quaternary ammonium salt through hydrogen bonding and other interactions, it lacks active groups that can covalently crosslink with amino groups. The two are unable to form a stable three-dimensional network structure, resulting in a loose membrane with weak adhesion, which cannot effectively coat the microfibrils on the fiber surface, leading to an increased fibrillation index. At the same time, the membrane provides insufficient protection for the fibers, resulting in a decrease in the retention rate of breaking strength, a reduction in dye binding sites, and a decrease in fixation rate.

[0061] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the products, methods and principles of this application should be covered within the scope of protection of this application.

Claims

1. A method for enzymatic refining of cotton blended with cellulose bio-fibers, characterized in that, Includes the following steps: S1. The greige fabric blended with cotton and cellulose bio-fibers is immersed in an α-amylase solution for treatment, followed by rinsing, dehydration, and drying. S2. The fabric obtained in step S1 is immersed in the working solution for treatment, then taken out, washed, dehydrated and dried; the working solution includes aminated mesoporous silica immobilized pectinase and fatty alcohol polyoxyethylene ether. S3. The fabric obtained in step S2 is immersed in a chitosan quaternary ammonium salt solution for impregnation treatment and pre-drying; then immersed in an oxidized tannic acid solution for impregnation treatment and drying, washing, and drying.

2. The enzyme refining method according to claim 1, characterized in that, In step S2, the working solution includes aminated mesoporous silica immobilized pectinase at a mass concentration of 1.4-1.6 g / L and fatty alcohol polyoxyethylene ether at a mass concentration of 2.0-2.4 g / L.

3. The enzyme refining method according to claim 1, characterized in that, The preparation method of aminated mesoporous silica-immobilized pectinase in the working solution of step S2 includes the following steps: a1. Disperse SBA-15 in toluene, add 3-aminopropyltriethoxysilane, reflux; centrifuge, wash, and dry to obtain NH2-SBA-15; a2. Disperse the NH2-SBA-15 obtained in step a1 in a buffer solution, add glutaraldehyde, shake, centrifuge, and wash to obtain the activated carrier. a3. Disperse the activated carrier obtained in step a2 in a buffer solution, add pectinase, shake at low temperature, add more pectinase, shake at room temperature, add NaBH4 solution, react, centrifuge, wash, and dry to obtain aminated mesoporous silica immobilized pectinase.

4. The enzyme refining method according to claim 3, characterized in that, In step a3, the mass ratio of the activated carrier to total pectinase is 20:(3-5).

5. The enzyme refining method according to claim 1, characterized in that, In step S3, the mass concentration of chitosan quaternary ammonium salt is 1.1-1.3 g / L, and the mass concentration of oxidized tannic acid is 0.2-0.4 g / L.

6. The enzyme refining method according to claim 1, characterized in that, In step S3, the mass concentration ratio of chitosan quaternary ammonium salt to oxidized tannic acid is (2.75-6.5):

1.

7. The enzyme refining method according to claim 1, characterized in that, In step S1, the mass concentration of α-amylase is 0.3-1.0 g / L, the pH of the treatment is 6.5-7.0, the treatment temperature is 42-48℃, and the treatment time is 15-25 min.

8. The enzyme refining method according to claim 1, characterized in that, In step S2, the pH value is 6.2-6.8, the temperature is 40-48℃, and the time is 45-75 min.

9. The enzyme refining method according to claim 1, characterized in that, In step S3, the pH of the chitosan quaternary ammonium salt solution is 5.0-6.0, the immersion temperature is 35-45℃, and the immersion time is 15-25 min; the pH of the oxidized tannic acid solution is 5.0-5.5, the immersion temperature is 25-35℃, and the immersion time is 8-15 min.

10. The enzyme refining method according to claim 1, characterized in that, The cellulose biofiber is selected from at least one of viscose, lyocell, and modal.

Images