A fungal enzyme debleaching method for all-cotton non-woven fabrics based on supercritical carbon dioxide

Abstract

The present invention belongs to the technical field of de-bleaching, and discloses a method for de-bleaching all-cotton non-woven fabrics using a fungal enzyme based on supercritical carbon dioxide. The method for de-bleaching all-cotton non-woven fabrics using a fungal enzyme based on supercritical carbon dioxide comprises the following steps: (1) placing an un-de-bleached all-cotton non-woven fabric in a culture medium of Aspergillus niger for treatment to obtain a first-treated all-cotton non-woven fabric; (2) placing the first-treated all-cotton non-woven fabric in a mixed solvent for de-bleaching with a supercritical carbon dioxide fluid to obtain a second-treated all-cotton non-woven fabric; (3) placing the second-treated all-cotton non-woven fabric in a free radical scavenger for ultrasonic treatment, and then sequentially washing and drying to obtain the de-bleached all-cotton non-woven fabric. The de-bleaching method of the present invention solves the problems of high energy consumption, large amount of waste discharge, and easy yellowing of the product in the traditional de-bleaching process, and is suitable for large-scale promotion and application.

Description

Technical Field

[0001] The invention relates to the technical field of de-bleaching, and in particular to a fungal bio-enzyme de-bleaching method for all-cotton non-woven fabrics based on supercritical carbon dioxide. Background Art

[0002] Due to their soft, fluffy feel, and high hygroscopicity, all-cotton non-woven fabrics have become widely used in daily life. However, during the production process, all-cotton non-woven fabrics typically require de-bleaching. Traditional de-bleaching generally uses high-temperature chemical bleaching (for example, Chinese invention patent CN106637664A discloses a cold-batch production process for pure cotton spunlace non-woven fabrics, where the processing temperature is 105-135°C) or high-alkali concentration chemical bleaching (for example, Chinese invention patent CN107675506A discloses a production process for spunlace non-woven fabrics, where the caustic soda concentration used is 15g / L and the hydrogen peroxide concentration is 30g / L). In addition to requiring large amounts of chemicals, these processes also result in significant energy and water consumption. With the introduction of the dual carbon goals, the research and application of environmentally friendly de-bleaching technologies have attracted considerable attention. The application of supercritical carbon dioxide fluid, a non-toxic and harmless substance, in the chemical, pharmaceutical, and food industries has achieved remarkable results. Carbon dioxide itself is non-flammable, with low critical temperature (31.1°C) and critical pressure (7.27MPa). When in a supercritical state, it is very sensitive to changes in temperature and pressure and possesses unique physical properties, such as low viscosity, high density, and excellent flow, mass transfer, heat transfer, and solubility. Therefore, supercritical carbon dioxide fluid has great potential as a new de-bleaching solvent.

[0003] Ozone has a strong oxidizing property and can play a good bleaching role, fading most pigments and oxidizing unsaturated organic compounds at low temperatures. The prior art has proven that ozone can be used for the debleaching of all-cotton spunlace nonwovens. For example, Chinese invention patent CN116145413A discloses a method for treating nonwovens with enzyme-assisted ozone. This method first uses enzyme cold stacking and then exposes it to ozone gas for debleaching. The process is relatively cumbersome, and the fabric after ozone treatment will have residual hydroxyl radicals and active oxygen atoms, which can cause problems such as yellowing of the fabric during subsequent storage. Therefore, it is necessary to develop a debleaching technology with low energy consumption, high product quality, and no yellowing, and an environmentally friendly debleaching process. Summary of the Invention

[0004] The purpose of the present invention is to provide a fungal enzyme debleaching method for all-cotton non-woven fabrics based on supercritical carbon dioxide, so as to solve the problems of high energy consumption, large sewage discharge, and easy yellowing of products in the traditional debleaching process.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide, comprising the following steps:

[0007] (1) treating an unbleached cotton nonwoven fabric in a culture medium of Aspergillus niger to obtain a first treated cotton nonwoven fabric;

[0008] (2) placing the first treated cotton nonwoven fabric in a mixed solvent for supercritical carbon dioxide fluid debleaching to obtain a second treated cotton nonwoven fabric;

[0009] (3) placing the second treated cotton nonwoven fabric in a free radical scavenger for ultrasonic treatment, and then washing and drying the fabric in sequence to obtain a debleached cotton nonwoven fabric;

[0010] The mixed solvent is a supercritical carbon dioxide fluid containing composite biological enzymes and ozone water; the composite biological enzymes include mixed enzymes, refined degreasing agent, sodium phytate and methyl tert-butyl ether; and the mixed enzymes include pectinase, laccase, proteinase and lipase.

[0011] Preferably, the pH value of the Aspergillus niger culture medium is 5-6; the Aspergillus niger culture medium comprises Aspergillus niger, glucose, casein tryptic digest, agar, chloramphenicol and water; the preservation number of Aspergillus niger is CGMCC No.9778; in the Aspergillus niger culture medium, the amount of Aspergillus niger added is 9-15 mL / L, the amount of glucose added is 30-50 g / L, the amount of casein tryptic digest added is 4-6 g / L, the amount of agar added is 12-15 g / L, and the amount of chloramphenicol added is 0.1-0.2 g / L.

[0012] Preferably, the treatment is carried out in an oxygen atmosphere, the treatment temperature is 25 to 40° C., and the treatment time is 1.5 to 3 hours.

[0013] Preferably, in the mixed solvent, the mass ratio of the composite biological enzyme, ozone water and supercritical carbon dioxide fluid is 1-4:800-1200:400-600, and the concentration of ozone water is 5-16 mg / L.

[0014] Preferably, the mass ratio of the pectinase, laccase, proteinase and lipase is 0.7-1.5:0.5-1.2:0.5-1.2:0.2-0.8.

[0015] Preferably, in the composite biological enzyme, the concentration of the refined deoiling agent is 1-2.5 g / L, the concentration of sodium phytate is 3-5 g / L, and the concentration of methyl tert-butyl ether is 1.5-4.5 g / L.

[0016] Preferably, the pressure of the supercritical carbon dioxide fluid debleaching is 15-20 MPa, the temperature of the supercritical carbon dioxide fluid debleaching is 30-60° C., and the time of the supercritical carbon dioxide fluid debleaching is 0.5-1.5 h.

[0017] Preferably, the free radical scavenger comprises catalase, a reducing blue dye and a solvent, the reducing blue dye comprises indigo, and the solvent comprises water; in the free radical scavenger, the concentration of catalase is 1 to 2.5 g / L, and the concentration of the reducing blue dye is 0.05 to 0.1 g / L.

[0018] Preferably, the frequency of the ultrasonic treatment is 50 to 100 kHz, and the time of the ultrasonic treatment is 0.5 to 1 hour.

[0019] Preferably, the number of times of washing is 3 to 6 times; and the temperature of drying is 50 to 70°C.

[0020] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention mixes supercritical carbon dioxide fluid with ozone water, and can utilize the low surface tension and diffusivity of supercritical carbon dioxide fluid to improve the contact between ozone water and cotton non-woven fabric, so that a sufficient reaction occurs between them, thereby achieving the ideal effect.

[0022] 2. The present invention utilizes the fungus Aspergillus niger to treat all-cotton non-woven fabrics. Aspergillus niger is a fermentation industrial strain that can produce a variety of substances that are beneficial to de-bleaching, such as cellulase, pectinase, protease, amylase, and glucose oxidase. The specificity and multi-effect synergistic performance of the enzyme effectively remove impurities on the cotton fiber, and add a refining degreasing agent, sodium phytate, and methyl tert-butyl ether to the composite biological enzyme agent. The refining degreasing agent has the functions of degreasing and penetration, thereby improving the de-bleaching efficiency; sodium phytate is a pure natural green additive that has a strong chelating effect with metal ions, making preparations for subsequent cleaning to remove the chelate to prevent the color of the metal ions from affecting the whiteness; methyl tert-butyl ether (MTBE) can wash out impurities such as fatty acids, resin acids, glycerides, sterol esters, and lignin, preventing these substances from remaining on the surface of the all-cotton non-woven fabric.

[0023] 3. The present invention uses catalase and indigo for further treatment. Since hydroxyl radicals, active oxygen atoms, etc. will remain after the cotton non-woven fabric is debleached with ozone water, it is easy to turn yellow, which affects the whiteness after debleaching. Ultrasound can accelerate the reaction rate of the enzyme and promote the decomposition of the pigment. Therefore, the cotton non-woven fabric after the reaction is further treated in a free radical scavenger, which can effectively solve the yellowing problem. DETAILED DESCRIPTION

[0024] The present invention provides a method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide, comprising the following steps:

[0025] (1) treating an unbleached cotton nonwoven fabric in a culture medium of Aspergillus niger to obtain a first treated cotton nonwoven fabric;

[0026] (2) placing the first treated cotton nonwoven fabric in a mixed solvent for supercritical carbon dioxide fluid debleaching to obtain a second treated cotton nonwoven fabric;

[0027] (3) placing the second treated cotton nonwoven fabric in a free radical scavenger for ultrasonic treatment, and then washing and drying the fabric in sequence to obtain a debleached cotton nonwoven fabric;

[0028] The mixed solvent is a supercritical carbon dioxide fluid containing composite biological enzymes and ozone water; the composite biological enzymes include mixed enzymes, refined degreasing agent, sodium phytate and methyl tert-butyl ether; and the mixed enzymes include pectinase, laccase, proteinase and lipase.

[0029] In the present invention, the pH value of the Aspergillus niger culture medium is preferably 5 to 6, more preferably 5.2 to 5.8, and more preferably 5.5 to 5.7; the Aspergillus niger culture medium comprises Aspergillus niger, glucose, casein tryptic digest, agar, chloramphenicol and water; the deposit number of Aspergillus niger is CGMCC No. 9778; in the Aspergillus niger culture medium, the amount of Aspergillus niger added is preferably 9 to 15 mL / L, more preferably 10 to 14 mL / L, and more preferably 12 to 13mL / L; the amount of glucose added is preferably 30-50g / L, more preferably 35-45g / L, more preferably 40g / L; the amount of casein tryptic digest added is preferably 4-6g / L, more preferably 4.5-5.5g / L, more preferably 5g / L; the amount of agar added is preferably 12-15g / L, more preferably 13-14g / L; the amount of chloramphenicol added is preferably 0.1-0.2g / L, more preferably 0.15g / L.

[0030] In the present invention, the treatment is carried out under an oxygen atmosphere; the treatment temperature is preferably 25-40°C, more preferably 30-38°C, and more preferably 32-35°C; the treatment time is preferably 1.5-3h, more preferably 2-2.5h.

[0031] In the mixed solvent of the present invention, the mass ratio of the composite biological enzyme, ozone water and supercritical carbon dioxide fluid is preferably 1-4:800-1200:400-600, more preferably 1.5-3.7:900-1100:430-550, and more preferably 2.7-3.4:960-1030:450-530; the concentration of ozone water is preferably 5-16 mg / L, more preferably 8-15 mg / L, and more preferably 10-12 mg / L.

[0032] In the present invention, the mass ratio of pectinase, laccase, proteinase and lipase is preferably 0.7-1.5:0.5-1.2:0.5-1.2:0.2-0.8, more preferably 0.8-1.2:0.6-1:0.6-1:0.3-0.7, and more preferably 0.9-1:0.7-0.8:0.7-0.9:0.5-0.6.

[0033] In the present invention, the refining deoiling agent includes tetraacetylethylenediamine; in the composite biological enzyme, the concentration of the refining deoiling agent is preferably 1-2.5 g / L, more preferably 1.5-2.2 g / L, more preferably 1.8-2 g / L; the concentration of sodium phytate is preferably 3-5 g / L, more preferably 3.5-4.5 g / L, more preferably 3.8-4 g / L; the concentration of methyl tert-butyl ether is preferably 1.5-4.5 g / L, more preferably 2-4 g / L, more preferably 2.5-3 g / L.

[0034] In the present invention, the pressure of the supercritical carbon dioxide fluid debleaching is preferably 15-20 MPa, more preferably 16-19 MPa, and more preferably 17-18 MPa; the temperature of the supercritical carbon dioxide fluid debleaching is preferably 30-60°C, more preferably 35-55°C, and more preferably 40-50°C; the time of the supercritical carbon dioxide fluid debleaching is preferably 0.5-1.5h, and more preferably 1h.

[0035] In the present invention, the free radical scavenger includes catalase, a reducing blue dye and a solvent, the reducing blue dye includes indigo, and the solvent includes water; in the free radical scavenger, the concentration of catalase is preferably 1 to 2.5 g / L, more preferably 1.5 to 2 g / L, and more preferably 1.6 to 1.8 g / L; the concentration of the reducing blue dye is preferably 0.05 to 0.1 g / L, more preferably 0.06 to 0.09 g / L, and more preferably 0.07 to 0.08 g / L.

[0036] In the present invention, the frequency of the ultrasonic treatment is preferably 50 to 100 kHz, more preferably 60 to 90 kHz, and more preferably 70 to 80 kHz; the time of the ultrasonic treatment is preferably 0.5 to 1 h, and more preferably 40 to 50 min.

[0037] Preferably, the number of times of washing is 3 to 6 times; and the temperature of drying is 50 to 70°C.

[0038] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0039] The pH value of the Aspergillus niger culture medium used in the following examples and comparative examples is 6; the Aspergillus niger culture medium comprises Aspergillus niger, glucose, casein tryptic digest, agar, chloramphenicol and water; the deposit number of Aspergillus niger is CGMCC No. 9778; in the Aspergillus niger culture medium, the amount of Aspergillus niger added is 9-15 mL / L, the amount of glucose added is 40 g / L, the amount of casein tryptic digest added is 5 g / L, the amount of agar added is 15 g / L, and the amount of chloramphenicol added is 0.1 g / L.

[0040] Example 1

[0041] This embodiment provides a method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide, and the specific steps are as follows:

[0042] (1) placing the unbleached cotton nonwoven fabric in a niger culture medium (the amount of niger added is 9.5 mL / L) in a closed space with oxygen aerated for 2 h at a temperature of 30° C. to obtain a first treated cotton nonwoven fabric;

[0043] (2) Pectinase, laccase, proteinase and lipase were prepared into a mixed enzyme in a mass ratio of 0.9:0.7:0.6:0.4; tetraacetylethylenediamine (TAED), sodium phytate and methyl tert-butyl ether were added to the mixed enzyme to ensure that the concentration of the refined degreasing agent was 1.5 g / L, the concentration of sodium phytate was 3.2 g / L and the concentration of methyl tert-butyl ether (MTBE) was 2.1 g / L to obtain a composite bio-enzyme; the prepared composite bio-enzyme was introduced into an ozone water containing ozone water (the concentration of ozone water was 6 m g / L) of supercritical carbon dioxide fluid, ensuring that the mass ratio of the composite biological enzyme, ozone water and supercritical carbon dioxide fluid is 1.9:900:420 to obtain a mixed solvent; the first treated cotton non-woven fabric obtained in step (1) is subjected to supercritical carbon dioxide fluid debleaching in the mixed solvent, the supercritical carbon dioxide fluid debleaching time is 42 minutes, the supercritical carbon dioxide fluid debleaching temperature is 40° C., and the supercritical carbon dioxide fluid debleaching pressure is 15 MPa to obtain a second treated cotton non-woven fabric;

[0044] (3) mixing catalase, indigo and water to ensure that the concentration of catalase is 1.2 g / L and the concentration of indigo is 0.06 g / L to obtain a free radical scavenger; ultrasonically treating the second treated cotton non-woven fabric obtained in step (2) in the free radical scavenger at a frequency of 60 kHz and a time of 0.5 h; washing the ultrasonically treated cotton non-woven fabric 6 times, and drying at 60° C. to obtain a de-bleached cotton non-woven fabric.

[0045] Example 2

[0046] This embodiment provides a method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide, and the specific steps are as follows:

[0047] (1) placing the unbleached cotton nonwoven fabric in a niger culture medium (the amount of niger added is 12 mL / L) in a closed space with oxygen, the treatment time is 2.5 h, the treatment temperature is 35° C., and a first treated cotton nonwoven fabric is obtained;

[0048] (2) Pectinase, laccase, proteinase and lipase were prepared into a mixed enzyme in a mass ratio of 1.2:1:0.8:0.6; tetraacetylethylenediamine (TAED), sodium phytate and methyl tert-butyl ether were added to the mixed enzyme to ensure that the concentration of the refined degreasing agent was 1.7 g / L, the concentration of sodium phytate was 3.9 g / L and the concentration of methyl tert-butyl ether (MTBE) was 2.9 g / L to obtain a composite bio-enzyme; the prepared composite bio-enzyme was introduced into an ozone water containing ozone water (the concentration of ozone water was 11 mg / L). / L) of supercritical carbon dioxide fluid, ensuring that the mass ratio of the composite biological enzyme agent, ozone water and supercritical carbon dioxide fluid is 3.3:980:510 to obtain a mixed solvent; the first treated cotton non-woven fabric obtained in step (1) is subjected to supercritical carbon dioxide fluid debleaching in the mixed solvent, the supercritical carbon dioxide fluid debleaching time is 54min, the supercritical carbon dioxide fluid debleaching temperature is 50°C, and the supercritical carbon dioxide fluid debleaching pressure is 17MPa, to obtain a second treated cotton non-woven fabric;

[0049] (3) mixing catalase, indigo and water to ensure that the concentration of catalase is 1.8 g / L and the concentration of indigo is 0.07 g / L to obtain a free radical scavenger; ultrasonically treating the second treated cotton non-woven fabric obtained in step (2) in the free radical scavenger at a frequency of 80 kHz and a time of 42 min; washing the ultrasonically treated cotton non-woven fabric 6 times, and drying at 60° C. to obtain a de-bleached cotton non-woven fabric.

[0050] Example 3

[0051] This embodiment provides a method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide, and the specific steps are as follows:

[0052] (1) placing the unbleached cotton nonwoven fabric in a niger culture medium (the amount of niger added is 14 mL / L) in a closed space with oxygen, treating the fabric for 3 h at a temperature of 40° C. to obtain a first treated cotton nonwoven fabric;

[0053] (2) Pectinase, laccase, proteinase and lipase were prepared into a mixed enzyme in a mass ratio of 1.5:1.2:1.1:0.8; tetraacetylethylenediamine (TAED), sodium phytate and methyl tert-butyl ether were added to the mixed enzyme to ensure that the concentration of the refined degreasing agent was 2.3 g / L, the concentration of sodium phytate was 4.7 g / L and the concentration of methyl tert-butyl ether (MTBE) was 4.4 g / L to obtain a composite bio-enzyme; the prepared composite bio-enzyme was introduced into an ozone water containing ozone water (the concentration of ozone water was 15 mg / L) of supercritical carbon dioxide fluid, ensuring that the mass ratio of the composite biological enzyme agent, ozone water and supercritical carbon dioxide fluid is 3.7:1100:550 to obtain a mixed solvent; the first treated cotton non-woven fabric obtained in step (1) is subjected to supercritical carbon dioxide fluid debleaching in the mixed solvent, the supercritical carbon dioxide fluid debleaching time is 1.5h, the supercritical carbon dioxide fluid debleaching temperature is 60°C, and the supercritical carbon dioxide fluid debleaching pressure is 20MPa to obtain a second treated cotton non-woven fabric;

[0054] (3) mixing catalase, indigo and water to ensure that the concentration of catalase is 2.3 g / L and the concentration of indigo is 0.09 g / L to obtain a free radical scavenger; ultrasonically treating the second treated cotton non-woven fabric obtained in step (2) in the free radical scavenger at a frequency of 100 kHz and a time of 1 h; washing the ultrasonically treated cotton non-woven fabric 6 times, and drying at 60° C. to obtain a de-bleached cotton non-woven fabric.

[0055] Comparative Example 1

[0056] The difference from Example 2 is that the treatment in the Aspergillus niger culture medium in step (1) is omitted, and the rest is the same as Example 2.

[0057] Comparative Example 2

[0058] The difference from Example 2 is that the treatment in the Aspergillus niger culture medium in step (1) is omitted, and "pectinase, laccase, proteinase, and lipase are composed of a mixed enzyme in a mass ratio of 1.2:1:0.8:0.6" is replaced by "cellulase, pectinase, proteinase, lipase, xylanase, and glucose oxidase are composed of a mixed enzyme in a mass ratio of 2:1.2:0.8:0.6:2.1:2.7", and the rest is the same as Example 2.

[0059] Comparative Example 3

[0060] The difference from Example 2 is that the treatment in the Aspergillus niger culture medium in step (1) and the ultrasonic treatment in the free radical scavenger in step (3) are omitted, and the rest are the same as in Example 2.

[0061] Performance testing:

[0062] The whiteness, pectin removal rate, cotton wax removal rate, friction coefficient and water absorption of the debleached and bleached cotton non-woven fabrics obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were tested. The test methods and results are as follows.

[0063] Test method:

[0064] 1. Whiteness: Using a WSD-Ⅱ d / o whiteness meter, refer to GB / T8425-1987 "Instrumental Assessment of Whiteness of Textiles." Stack the samples into two layers and measure four times at different locations on each sample, taking the average value. The nominal value of the standard whiteness plate is 71.3.

[0065] 2. Pectin removal rate: Using the ammonium oxalate extraction-carbazole colorimetric method: Weigh 1.5g of the sample, cut it into pieces and place it in a 250mL flask, add 100mL of 0.5% ammonium oxalate solution, connect a condenser, boil in a boiling water bath for 1.5h, filter, take 2mL of the filtrate, add it to 12mL of concentrated sulfuric acid and cool it with ice water, then boil it in a boiling water bath for 10min and then cool it with cold water at 0℃, finally add 1mL of 0.15% carbazole anhydrous ethanol solution, mix well, let it stand for 30min, and measure the absorbance at a wavelength of 530nm using a 721 spectrophotometer. Then calculate the mass fraction of galacturonic acid from the standard curve to obtain the mass fraction of pectin. The mass fraction of pectin in the unbleached and bleached cotton non-woven fabrics was measured by the above method, and the pectin removal rate was calculated.

[0066] 3. Cotton Wax Removal Rate: Weigh 10g (accurate to 0.0001g) of a shredded sample pre-dried in a 105°C oven to a constant weight. Place the sample in a filter paper tube in a fat extractor, 1.5cm above the top of the extractor's siphon tube. The sample's height in the filter paper tube should be 1.5cm below the top of the siphon tube. Add 120mL of carbon tetrachloride to the fat extractor flask and place it in a constant-temperature water bath. Adjust the temperature to maintain a siphoning cycle of the solvent four times per hour. Extract for 3 hours, then cool. Filter the extract containing the waxy substance from the extractor flask into a flask of known weight. Wash the extractor flask, filter paper, and funnel three times with solvent and heat in a water bath for distillation. Once all the solvent has evaporated, place the flask in an oven at 105°C to a constant weight. After cooling, accurately weigh it. The mass of the cotton wax in the unbleached cotton non-woven fabric and the mass of the cotton wax in the debleached cotton non-woven fabric are measured by the above method, and then the cotton wax removal rate is calculated.

[0067] 4. Friction coefficient: The FTT fabric touch tester, developed by SDL ATLAS and the Hong Kong Polytechnic University, was used. Three samples were taken from each test piece, each measuring 31 cm x 31 cm. Each sample was cut into an identical "L"-shaped specimen, each 11 cm wide. The contact comfort of the specimens was determined by mechanical testing under micro-deformation.

[0068] 5. Water absorption: The water absorption of 100% cotton spunlace nonwovens is tested according to GB / T24218.6-2010 "Textiles - Test Methods for Nonwovens - Part 6: Determination of Absorbency". A sample with a size of 100mm x 100mm is weighed, placed in water for 60 seconds, removed, and hung vertically for 120 seconds before being weighed again to calculate the water absorption.

[0069] The above test results are shown in Table 1.

[0070] Table 1 Performance test results of the debleached cotton nonwoven fabrics obtained in Examples 1 to 3 and Comparative Examples 1 to 3

[0071]

[0072]

[0073] As can be seen from Table 1, the present invention provides a de-bleaching technology with low energy consumption, high product quality, and low yellowing, and a green and environmentally friendly de-bleaching process. The cotton non-woven fabric de-bleached by the de-bleaching method of the present invention has higher whiteness, pectin removal rate and cotton wax removal rate. At the same time, the obtained de-bleached cotton non-woven fabric has a low friction coefficient, excellent comfort of the fabric, and strong moisture absorption capacity.

[0074] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for debleaching cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide, characterized in that: The steps include: (1) treating the unbleached cotton nonwoven fabric in a culture medium of Aspergillus niger to obtain a first treated cotton nonwoven fabric; (2) placing the first treated cotton nonwoven fabric in a mixed solvent and performing supercritical carbon dioxide fluid debleaching to obtain a second treated cotton nonwoven fabric; (3) placing the second treated cotton nonwoven fabric in a free radical scavenger for ultrasonic treatment, and then washing and drying the fabric in sequence to obtain a debleached cotton nonwoven fabric; The mixed solvent is a supercritical carbon dioxide fluid containing composite biological enzymes and ozone water; the composite biological enzymes include mixed enzymes, refined degreasing agent, sodium phytate and methyl tert-butyl ether; the mixed enzymes include pectinase, laccase, proteinase and lipase; The free radical scavenger includes catalase, a reduced blue dye and a solvent.

2. The method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide according to claim 1, characterized in that: The pH value of the Aspergillus niger culture medium is 5-6; the Aspergillus niger culture medium comprises Aspergillus niger, glucose, casein tryptic digest, agar, chloramphenicol and water; the preservation number of Aspergillus niger is CGMCC No.9778; and in the Aspergillus niger culture medium, the amount of Aspergillus niger added is 9-15 mL / L, the amount of glucose added is 30-50 g / L, the amount of casein tryptic digest added is 4-6 g / L, the amount of agar added is 12-15 g / L, and the amount of chloramphenicol added is 0.1-0.2 g / L.

3. The method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide according to claim 1 or 2, characterized in that: In the step (1), the treatment is carried out in an oxygen atmosphere, the treatment temperature is 25-40° C., and the treatment time is 1.5-3 h.

4. The method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide according to claim 3, characterized in that: In the mixed solvent, the mass ratio of the composite biological enzyme, ozone water and supercritical carbon dioxide fluid is 1-4:800-1200:400-600, and the concentration of ozone water is 5-16 mg / L.

5. The method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide according to claim 1, 2 or 4, characterized in that: The mass ratio of the pectinase, laccase, proteinase and lipase is 0.7-1.5:0.5-1.2:0.5-1.2:0.2-0.

8.

6. The method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide according to claim 5, characterized in that: In the composite biological enzyme, the concentration of the refined degreasing agent is 1-2.5 g / L, the concentration of sodium phytate is 3-5 g / L, and the concentration of methyl tert-butyl ether is 1.5-4.5 g / L.

7. The method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide according to claim 6, characterized in that: The pressure of the supercritical carbon dioxide fluid debleaching is 15-20 MPa, the temperature of the supercritical carbon dioxide fluid debleaching is 30-60° C., and the time of the supercritical carbon dioxide fluid debleaching is 0.5-1.5 h.

8. The method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide according to claim 6 or 7, characterized in that: In the free radical scavenger, the reducing blue dye includes indigo, and the solvent includes water; in the free radical scavenger, the concentration of catalase is 1-2.5 g / L, and the concentration of the reducing blue dye is 0.05-0.1 g / L.

9. The method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide according to claim 8, characterized in that: The frequency of the ultrasonic treatment is 50-100 kHz, and the time of the ultrasonic treatment is 0.5-1 h.

10. The method for debleaching all-cotton non-woven fabrics using fungal enzymes based on supercritical carbon dioxide according to claim 9, characterized in that: The number of times of washing is 3 to 6 times; and the temperature of drying is 50 to 70°C.

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