NL2026586B1

NL2026586B1 - Environment-friendly desizing method for fabric

Info

Publication number: NL2026586B1
Application number: NL2026586A
Authority: NL
Inventors: Li Zheng; Liu Jia; Lu Wenyu; Li Xiang; Gong Jixian; Zhang Jianfei; Li Qiujin; Xuan Jie
Original assignee: Beijing Hongming Xinda Tech Co Ltd
Priority date: 2020-09-30
Filing date: 2020-09-30
Publication date: 2021-02-04
Also published as: NL2026586A

Abstract

Disclosed is an environment-friendly desizing method for fabric, which relates to the field of textile technology. Specifically, the desizing method of the disclosure includes steps of performing desizing reaction, washing and drying in sequence for the fabric, wherein during the desizing reaction, the fabric is immersed in a desizing fluid, and the desizing fluid is composed of sodium hydroxide of 8-16g / L, sophorolipid of 0.5-3g / L and a remainder of water. The desizing method of the disclosure is not only low-toxic, environmentally friendly, and highly efficient in desizing, but also has a broad desizing application range, so as to be applied in cotton fabrics, cotton-polyester blends and other fabrics.

Description

ENVIRONMENT-FRIENDLY DESIZING METHOD FOR FABRIC FIELD OF TECHNOLOGY

[0001] The disclosure relates to the field of textile technology, in particular, to an environment-friendly desizing method for fabric.

BACKGROUND

[0002] Alkali desizing is a popular desizing method used by printing and dyeing enterprises in China. It has strong applicability and can be used for desizing of various natural and synthetic pulps. In order to simplify or shorten the process, and to improve processing efficiency and product quality, surfactants are generally added to improve process efficiency.

[0003] At present, desizing agents that are widely used are generally industrial chemical reagents or complex enzymes. For example, the patent with publication number CN108505318A discloses "a new desizing agent and a preparation method therefor”, wherein the agent has a good desizing effect and less damage to the fabric; the treated fabric has good wool effect, and feel and whiteness; and it has good permeability and dispersion, with refining effect. The disclosure provides a desizing agent, which includes the following components in parts by weight: sodium hydroxide: 2-8, nonylphenol polyoxyethylene ether: 15-20, dodecyltrimethylammonium chloride: 5-10, glycerol cocoate: 5-10, cocoic acid monoisopropanolamide: 2-7, isocetyl stearate: 6-12, polydimethylsiloxane: 1-3, sodium laurate: 2-6, ethylene glycol: 4-8, polyvinylpyrrolidone: 1-4, ammonium persulfate: 2-6, potassium chloride: 1-4, nano zinc oxide: 1-4, ethylhexyl palmitate: 2-5, propanol: 8-15, water: 25-35. The desizing rate for the fabric treated with the desizing agent provided by the disclosure is above 96.1%, and the fabric is not damaged.

[0004] However, in terms of current industrial desizing applications, surfactants composed of organic chemical structures are not only harmful to the environment, but also have certain toxicity to degradation metabolites. For example, alkylphenol polyoxyethylene ether (APEO) is more toxic, and APEO products have been restricted or banned. Therefore, recently, people have begun to study the application of new environmentally friendly reagents to the textile industry,

[0005] such as a process using complex enzyme for desizing. For example. the patent with publication number CN100424257C discloses “Method for desizing, scouring and bleaching all fabrics with enzyme”, pertaining to the compounding of multiple enzyme preparations and its application in the field of fabric pretreatment technology. The enzyme for compounding includes Alpha-amylase, PVA degrading enzyme, lipase, protease, alkaline pectinase, xylanase, cellulase, sugar oxidase, catalase, etc., and according to the different requirements of fabric pretreatment,

different compounding enzyme preparations are used for desizing, scouring and bleaching of the fabric, so as to substitute traditional chemical treatment method in which JFC-E is also selectively included in the compounding enzyme preparations. Replacing traditional chemical treatment method using concentrated alkali and high temperature with this method saves energy and saves consumption and is environmentally friendly.

[0006] But for desizing agents composed of complex enzymes, since the characteristics of enzyme catalysis are generally highly specific, different types of enzyme preparations has to be selected for desizing slurries with different ingredients. Therefore, for complex slurry, multiple complex enzyme preparations are required, then not only the process is complicated. but also the labor cost is high, and the application is often limited by temperature and application conditions.

[0007] In view of the above problems, a desizing active agent is urgently needed, which not only has properties of low toxicity, environmentally friendliness, effectively slowing or reducing the environmental pollution of desizing waste liquid for fabric, but also can simplify the desizing method as well as effectively saving material cost and time cost.

SUMMARY

[0008] The technical problem to be solved by the disclosure is to provide an environment- friendly desizing method with low toxicity, environmental friendliness and wide applicability, so as to slow down or reduce the environmental pollution of desizing waste liquid for fabric, improve desizing efficiency and save process cost.

[0009] In order to achieve above purpose, the disclosure employs the following technical schemes:

[0010] An environment-friendly desizing method for fabric includes a step of performing a desizing reaction, wherein a desizing fluid in the desizing reaction is used to desize the fabric, and the desizing fluid comprises lye and sophorolipid.

[0011] Preferably, the lye is a sodium hydroxide solution.

[0012] Preferably, in the desizing fluid, a final concentration of sodium hvdroxide is 8- 16g/L, and a final concentration of sophorolipid is 0.5-3g/L.

[0013] Preferably, an environment-friendly desizing method for fabric, the desizing method further comprises steps of washing and drying, wherein the desizing fluid is composed of sodium hydroxide of 8-16g / L. sophorolipid of 0.5-3g / L and a remainder of water.

[0014] Preferably, specifically, the desizing method for fabric includes steps of:

[0015] (1) preparation of desizing fluid: preparing a sodium hydroxide solution having a concentration of 8-16 g/L, then adding sophorolipid to the sodium hydroxide solution to obtain a desizing fluid, and controlling a final concentration of sophorolipid in the desizing fluid to 0.5-3g/L;

[0016] (2) desizing reaction: immersing the fabric in the desizing fluid, while controlling a bath ratio to 1:33-1:60, a reaction time to 30-50min and a reaction temperature to 95-105°C;

[0017] (3) washing: washing the fabric obtained in the step (2) until a washing liquid is neutral;

[0018] (4) drying the fabric washed with water in the step (3).

[0019] Preferably, the washing in the step (3) includes: washing the fabric obtained m the step (2) at different temperature gradients of 80-90 °C and 50-70 °C respectively, and finally washing with cold water until the washing liquid is neutral.

[0020] Preferably, in the step (4), the drying is specifically bake-drying or air-drying.

[0021] Preferably, the fabric is a pure cotton fabric or a polyester-cotton blended fabric.

[0022] More preferably, specifically, the desizing method for pure cotton fabric includes steps of:

[0023] (1) preparation of desizing fluid: preparing a sodium hydroxide solution having a concentration of 8-15g/L, then adding sophorolipid to the sodium hydroxide solution to obtain a desizing fluid, and controlling a final concentration of sophorolipid in the desizing fluid to 0.5-3g/L:

[0024] (2) desizing reaction: immersing the fabric in the desizing fluid, while controlling a bath ratio to 1:40-1:60, a reaction time to 30-50min and a reaction temperature to 95-105°C;

[0025] (3) washing: washing the fabric obtained in the step (2) at different temperature gradients of 80-90 °C and 50-60 °C respectively, and finally washing with cold water until the washing liquid is neutral;

[0026] (4) drying the fabric washed with water in the step (3).

[0027] More preferably, specifically, the desizing method for polyester-cotton blended fabric includes steps of:

[0028] (1) preparation of desizing fluid: preparing a sodium hydroxide solution having a concentration of 10-16g/L, then adding sophorolipid to the sodium hydroxide solution to obtain a desizing fluid, and controlling a final concentration of sophorolipid in the desizing fluid to 0.5-2g/L;

[0029] (2) desizing reaction: immersing the fabric in the desizing fluid, while controlling a bath ratio to 1:35-1:50, a reaction time to 30-40min and a reaction temperature to 100-105 °C:

[0030] (3) washing: washing the fabric obtained in the step (2) at different temperature gradients of 80-90 °C and 60-70 °C respectively, and finally washing with cold water until the washing liquid is neutral;

[0031] (4) drying the fabric washed with water in the step (3).

[0032] Beneficial effects:

[0033] I. Sophorolipids are the most promising biosurfactants among glycolipid biosurfactants. They have extremely low biological toxicity, are environmentally friendly, and may be biodegradable; they are suitable for extreme temperature, pH and salinity; they have good biocompatibility, and generally do not cause allergies. In recent vears, the biosurfactant sophorolipid has gradually been widely used in various fields such as daily chemical. medicine, and environmental engineering. However, the application of sophorolipid as desizing agent in desizing method for fabric has not been reported.

[0034] In the disclosure, innovatively, the sophorolipid is applied in desizing method for plants, and combining the desizing method of the disclosure, it is found that sophorolipid has a broad spectrum of desizing for different fabrics, and may be widely used in pure cotton fabrics and cotton-polyester blended fabrics and fabrics with different slurry components, and has a significant desizing effect especially for the three main components of slurry: polyvinyl alcohol (PVA), acrylic pulp, and modified starches while significantly reducing the content of residues of the slurry after desizing.

[0035] 2. Under the control of specific bath ratio, reaction temperature and reaction time, sophorolipid of the disclosure has obtained a significant mcrease 1n whiteness and a desizing rate, causing significant desizing effect.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present disclosure is described below through specific embodiments. In addition, the embodiments should be understood as illustrative, rather than limiting the scope of the disclosure, which is only limited by the scope of the claims. For those skilled in the art, without departing from the spirit and scope of the present disclosure, various changes or modifications to the material composition and amount used in these embodiments also belong to the protection scope of the present disclosure. It should be noted that, in the case of no conflicts, the embodiments and features in the embodiments of the disclosure can be combined mutually.

[0037] It should be noted that the environment-friendly desizing method for fabric in the disclosure may be broadly applied to the desizing process of different fabric raw materials in the existing industry, and since the fabric materials that requires desizing mainly include pure cotton fabrics and polyester-cotton blended fabrics in the prior art, the desizing processes of these two types of raw materials are mainly described in the following embodiments.

DESCRIPTION OF THE EMBODIMENTS

[0038] The present disclosure is described below through specific embodiments. In addition, the embodiments should be understood as illustrative, rather than limiting the scope of the disclosure, which is only limited by the scope of the claims. For those skilled in the art, without departing from the spirit and scope of the present disclosure, various changes or modifications to the material composition and amount used in these embodiments also belong to the protection scope 5 of the present disclosure. It should be noted that, in the case of no conflicts, the embodiments and features in the embodiments of the disclosure can be combined mutually.

[0039] It should be noted that the environment-friendly desizing method for fabric in the disclosure may be broadly applied to the desizing process of different fabric raw materials in the existing industry, and since the fabric materials that requires desizing mainly include pure cotton fabrics and polyester-cotton blended fabrics in the prior art, the desizing processes of these two types of raw materials are mainly described in the following embodiments.

Embodiment 1: An environment-friendly desizing method for pure cotton fabric In the present embodiment, before desizing, the slurry of the pure cotton fabric mainly includes a starch slurry or a starch-based mixed slurry. The pure cotton fabrics used in the following Embodiments 2-8 are the same as those in Embodiment 1.

(1) Preparation of desizing fluid: pouring sodium hydroxide into a prescribed amount of distilled water and stirring while pouring it until completely dissolved, then adding a surfactant and stirring well, so that in the desizing fluid, a final concentration of sodium hydroxide is 10g/L, and a final concentration of sophorolipid is 1g/L.

(2) desizing reaction: immersing the fabric in the desizing fluid, while controlling a bath ratio to 1:40, a reaction time to 30min and a reaction temperature to 100 °C; (3) washing twice with water at 85 °C and again twice at 55 °C, finally washing with cold water until the washing liquid is neutral; (4) drying the washed fabric.

Embodiment 2: An environment-friendly desizing method for pure cotton fabric It is known that before desizing, the slurry of the pure cotton fabric mainly includes a starch slurry or a starch-based mixed slurry.

(1) Preparation of desizing fluid: pouring sodium hydroxide into a prescribed amount of distilled water and stirring while pouring it until completely dissolved, then adding a surfactant and stirring well, so that in the desizing fluid, a final concentration of sodium hydroxide is 8g/L, and a final concentration of sophorolipid is 0.5g/L. (2) desizing reaction: immersing the fabric in the desizing fluid, while controlling a bath ratio to 1:40, a reaction time to 30min and a reaction temperature to 95 °C;

(3) washing twice with water at 80 °C and again twice at 50 °C, finally washing with cold water until the washing liquid is neutral; (4) drying the washed fabric. Embodiment 3: An environment-friendly desizing method for pure cotton fabrie It is known that before desizing, the slurry of the pure cotton fabric mainly includes a starch slurry or a starch-based mixed slurry. The operation method in the present embodiment is the same as that in Embodiment 1, except that: (1) Preparation of desizing fluid: a final concentration of sodium hydroxide is 15g/L., and a final concentration of sophorolipid is 3g/L. (2) desizing reaction: the bath ratio is 1:40, the reaction time is 50min and the reaction temperature is 105 °C; (3) washing twice with water at 90 °C and again twice at 55 °C, finally washing with cold water until the washing liquid is neutral; Embodiment 4: An environment-friendly desizing method for pure cotton fabric It is known that before desizing, the slurry of the pure cotton fabric mainly includes a starch slurry or a starch-based mixed slurry.

The operation method in the present embodiment is the same as that in Embodiment 1, except that: (1) Preparation of desizing fluid: a final concentration of sodium hydroxide is 12g/L, and a final concentration of sophorolipid is L5g/L: (2) the bath ratio is 1:50, the reaction time is 40min and the reaction temperature is 100 °C; (3) washing twice with water at 90 °C and again twice at 65 °C, finally washing with cold water until the washing liquid is neutral; Embodiment 5: Detection for properties of pure cotton fabric with different surfactants Different types of surfactants are selected for testing in properties of desizing: Itis known that before desizing, the slurry of the pure cotton fabric mainly includes a starch slurry or a starch-based mixed slurry. Grouping: Control group 1: JFC-E; Control group 2: High-efficiency scouring agent (surfactant commonly used in industry); Experimental group: Sophorolipid.

Method: Tests are performed for desizing on the surfactants of above-mentioned control group and experimental group according to the parameters and methods of the desizing method of Embodiment 1; Three parallel tests are performed for each group.

Before the test, the fabric weight of each group is accurately weighed for counting it as G.

After desizing, the fabrics of each group are individually dried in a 105 °C oven to constant weight, then the fabrics are taken out and placed in a dryer to cool to room temperature, and then a weight is accurately weighed for counting it as G'. Method for detection of desizing effect (1) Whiteness of fabrics before and after desizing Referring to the national standard GB/T17644-2008 "Test method for whiteness and chromaticity of textile fibers", a whiteness meter 1s used for testing, and the fabric is folded into 4 layers to measure 3 different positions and an average is taken.

U whiteness improvement (%) = whiteness of fabric after desizing-whiteness of fabric before desizing (2) Desizing rate of fabrics: desizing rate = (weight of fabric before desizing-weight of fabric after desizing)/sizing amount of fabric x 100%, the weight of the fabric before desizing = G (1-A), wherein A is the moisture content of the fabric, and the method for measuring is as follows: (D A is the moisture content of the fabric: the moisture content of the fabric: three parallel tests are performed for each group, and before the test, the fabric weight of each group is accurately weighed and counted as W.

The fabric is placed in an oven at 105 °C and baked to a constant weight, then taken out quickly for placing in a dryer and cooling to room temperature, and then a weight W' is weighed with an analysis balance for calculating the moisture content A of the fabric according to the following formula: A={(W-W")/Wx 100%. (Note: The moisture content refers to the moisture content in the fabric, which is used to calculate the desizing rate to avoid the influence of moisture on the desizing rate.) (2) The fabric for testing is weighed for counting it as G.

After desizing. the fabrics of cach group are individually dried in a 105 °C oven to constant weight, then the fabrics are taken out and placed in a dryer to cool to room temperature, and then a weight is accurately weighed for counting it as G'.

Test results: Table 1 shows the effects of the experimental and control groups after desizing.

Table 1: Comparison of properties of pure cotton fabrics with different surfactants Group: Whiteness | Standard | Desizing | Standard | Average | Average | Average Surfactant | improvement | deviation | rate (%) | deviation feel desizing | cottonseed (%) (level) Effect husk removal Experimental 4.76 0.17 95.73 0.13 5 Excellent | Excellent group: pee I I a Control 3.83 0.40 87.89 0.33 4 Excellent Good group 1: mo Control 442 0.22 85.89 0.19 3.5 Good Good group 2: Highly effective scourmg agent Note: Feel (level): 1-5 The higher the whiteness improvement and desizing rate, the better the desizing effect of the fabric.

Itcan be seen from Table 1 that the desizing rate of fabrics in case of the sophorolipid is the highest and stable.

By comprehensively combining the two parameters of whiteness improvement and desizing rate, the effect of sophorolipid is better.

The disclosure finds, for the first time, that in the process of desizing application of sophorolipid and JFC-E, the chemical oxygen demand (COD) of 1g/L sophorolipid is 1655mg/L, while the COD of the same concentration of JFC-E is as high as 2107mg/L, indicating obviously that the sophorolipid has a smaller impact on the ecological environment and is more environmentally friendly than JFC-E.

In addition, the sophorolipid may reduce the surface tension of water to 33.11 mN/m, indicating that the sophorolipid has excellent osmotic wetting properties.

It should be noted that Embodiments 2-4 of the disclosure may also obtain technical effects similar to those of Embodiment 1. Embodiment 6: Test for properties of bath ratio of pure cotton fabrics during desizing

Different parameters of bath ratios are selected for testing in properties of desizing: Grouping: Control group 1: bath ratio of 1:30 Control group 2: bath ratio of 1:70 Experimental group 1: bath ratio of 1:40 Experimental group 2: bath ratio of 1:50 Experimental group 3: bath ratio of 1:60 Method: Tests are performed for desizing on above-mentioned control groups and experimental groups according to the parameters and methods of the desizing method of Embodiment 1, except in that different bath ratios are controlled.

Three parallel tests are performed for each group. Before the test, the fabric weight of each group is accurately weighed for counting it as G. After desizing, the fabrics of each group are individually dried in a 105 °C oven to constant weight, then the fabrics are taken out and placed in a dryer to cool to room temperature, and then a weight is accurately weighed for counting it as G’.

Table 2 Test results: Table 2 Test for properties of different bath ratios Bath ratio Whiteness Standard | Desizing rate Standard deviation improvement | deviation (%) (%) Experimental 4.76 0.17 95.73 0.13 me | Experimental 3.88 0.15 92.42 0.16 mie | Experimental 3.76 0.45 89.11 0.05 | Control 5.24 0.78 93.12 0.66 ri | Control 3.10 0.23 81.45 0.16 win | As can be seen from the table above, in a range of bath ratio of 1: 40-1: 60, the whiteness improvement and desizing rate of the fabric have been significantly improved. However, when the bath ratio is 1:30, although the whiteness improvement and desizing rate of the fabric are high, the desizing stability is poor.

Embodiment 7: Test for properties of reaction temperature of pure cotton fabrics during desizing Different parameters of reaction temperatures are selected for testing in properties of desizing: Grouping: Control group 1: reaction temperature of 90 °C Control group 2: reaction temperature of 110 °C Experimental group 1: reaction temperature of 95 °C Experimental group 2: reaction temperature of 100 °C Experimental group 3: reaction temperature of 105 °C Method: Tests are performed for desizing on above-mentioned control groups and experimental groups according to the parameters and methods of the desizing method of Embodiment 1, except in that different reaction temperatures are controlled.

Three parallel tests are performed for each group.

After desizing, the fabrics of each group are individually dried in a 105 °C oven to constant weight, then the fabrics are taken out and placed in a dryer to cool to room temperature, and then a weight is accurately weighed for counting it as CG’. Table 3 Test results: Table 3 Test for properties of different reaction temperatures Temperature | Whiteness Standard | Desizing rate Standard (°C) improvement | deviation (%) deviation (%) Experimental 3.15 0.11 91.19 0.12 ms Experimental 4.76 0.17 95.73 0.13 men A a Experimental 4.48 0.20 92.24 0.14 mes Control 2.69 0.26 80.32 0.05 in| Control 5.52 0.65 95.82 0.67 rn | As can be seen from the table above, in a range of the reaction temperature of 95-105 °C, the desizing rate and whiteness improvement of the fabric are both significant.

Although the desizing effect of the fabric at 110 °C is better than that that at 100 °C, it has poor stability and low repeatability. From the perspective of energy saving, the reaction temperature of 110 °C is obviously not suitable for desizing.

Embodiment 8: Test for properties of reaction time of pure cotton fabrics during desizing Different parameters of reaction time are selected for testing in properties of desizing: Grouping: Control group 1: reaction temperature of 20min Control group 2: reaction temperature of 60min Experimental group 1: reaction temperature of 30min Experimental group 2: reaction temperature of 40min Experimental group 3: reaction temperature of 50min Method: Tests are performed for desizing on above-mentioned control groups and experimental groups according to the parameters and methods of the desizing method of Embodiment 1, except in that different reaction time are controlled.

Three parallel tests are performed for each group. Before the test, the fabric weight of each group is accurately weighed for counting it as G. After desizing, the fabrics of each group are individually dried m a 105 °C oven to constant weight, then the fabrics are taken out and placed m a dryer to cool to room temperature, and then a weight is accurately weighed for counting it as G'.

Table 4 Test results: Table 4 Test for properties of different reaction time Time Whiteness Standard Desizing rate Standard deviation (min) improvement deviation (%) (%o) As can be seen from the table above, in a range of the reaction time of 20-50min, the desizing rate and whiteness improvement of the fabric are both significantly improved. Although the desizing effect of the fabric is higher under the condition of a reaction time of 60min, its stability is poor and its repeatability is low. From the perspective of the desizing stability and the time cost of the process operation, this reaction time for desizing is obviously not suitable.

Embodiment 9: An environment-friendly desizing method for polyester-cotton blended fabric

In the present embodiment, before desizing the polyester-cotton fabric, the slurry mainly includes polyacrylate, PVA and starch. The polyester-cotton blended fabrics used in the following Embodiments 10-11, 13-16 are the same as those in Embodiment 9. (1) Preparation of desizing fluid: preparing a sodium hydroxide solution having a concentration of 12g/L, then adding sophorolipid to the sodium hydroxide solution to obtain a desizing fluid, and controlling a final concentration of sophorolipid in the desizing fluid to 1g/L; (2) desizing reaction: immersing the fabric in the desizing fluid, while controlling a bath ratio to 1:40, a reaction time to 30min and a reaction temperature to 100 °C; (3) washing twice with water at 85 °C and again twice at 65 °C, finally washing with cold water until the washing liquid is neutral; (4) drying the washed fabric. Embodiment 10: An environment-friendly desizing method for polyester-cotton blended fabric (1) Preparation of desizing fluid: preparing a sodium hydroxide solution having a concentration of 10g/L, then adding sophorolipid to the sodium hydroxide solution to obtain a desizing fluid, and controlling a final concentration of sophorolipid in the desizing fluid to 0.5g/L; (2) desizing reaction: immersing the fabric in the desizing fluid, while controlling a bath ratio to 1:35, a reaction time to 30min and a reaction temperature to 100 °C: (3) washing twice with water at 80°C and again twice at 60°C, finally washing with cold water until the washing liquid is neutral; (4) drying the washed fabric.

Embodiment 11: An environment-friendly desizing method for polyester-cotton blended fabric (1) Preparation of desizing fluid: preparing a sodium hydroxide solution having a concentration of 16g/L, then adding sophorolipid to the sodium hydroxide solution to obtain a desizing fluid, and controlling a final concentration of sophorolipid in the desizing fluid to 29/L; (2) desizing reaction: immersing the fabric in the desizing fluid, while controlling a bath ratio to 1:50, a reaction time to 40min and a reaction temperature to 105 °C;

(3) washing twice with water at 90 °C and again twice at 70 °C, finally washing with cold water until the washing liquid is neutral; (4) drying the washed fabric. Embodiment 12: An environment-friendly desizing method for polyester-cotton blended fabric In the present embodiment, before desizing the polvester-cotton fabric, the slurry mainly includes a mixed slurry of polyacrylate, PVA and CMC (carboxymethyl cellulose). (1) Preparation of desizing fluid: preparing a sodium hydroxide solution having a concentration of 12g/L., then adding sophorolipid to the sodium hydroxide solution to obtain a desizing fluid, and controlling a final concentration of sophorolipid in the desizing fluid to 1g/L; (2) desizing reaction: immersing the fabric in the desizing fluid, while controlling a bath ratio to 1:40, a reaction time to 35min and a reaction temperature to 100 °C; (3) washing twice with water at 85°C and again twice at 65°C, finally washing with cold water until the washing liquid is neutral; (4) drying the washed fabric. Embodiment 13: Detection for properties of polyester-cotton blended fabric with different surfactants Different types of surfactants are selected for testing in properties of desizing: Grouping: Control group 1: JFC-E; Control group 2: High-efficiency scouring agent (surfactant commonly used in industrv); Experimental group: Sophorolipid.

Method: Tests are performed for desizing on the surfactants of above-mentioned control group and experimental group according to the parameters and methods of the desizing method of Embodiment 9; three parallel tests are performed for each group.

The whiteness before and after desizing of the fabric in the method for detecting desizing effect and the method for detecting desizing rate of the fabric are the same as those in Embodiment 5. Test results: Table 5 shows the effects of the experimental and control groups after desizing,

Table 5: Comparison of properties of polyester-cotton blended fabrics with different surfactants Group: Whiteness | Standard | Desizing | Standard | Average | Average | Average Surfactant | improvement | deviation | rate (%) | deviation feel desizing | cottonseed (%) (level) effect husk removal Experimental 4.89 0.15 94.27 0.05 5 Excellent | Excellent group: Sophorolipid Control 2.58 0.05 86.12 0.10 3 Good Good group 1: JFC-E Control 3.05 0.14 84.00 0.12 4 Good Good group 2: Highly effective scouring agent Note: Feel (level): 1-5 As can be seen from the table above, the whiteness improvement and desizing rate of the fabrics in the experimental groups are significantly higher than those in the control groups.

It should be noted that Embodiments 10-12 of the disclosure may also obtain technical effects similar to those of Embodiment 9. Embodiment 14: Test for properties of bath ratio of polyester-cotton blended fabrics during desizing Different parameters of bath ratios are selected for testing in properties of desizing: Grouping: Control group 1: bath ratio of 1:30 Control group 2: bath ratio of 1:60 Experimental group 1: bath ratio of 1:40 Experimental group 2: bath ratio of 1:50 Method: Tests are performed for desizing on above-mentioned control groups and experimental groups according to the parameters and methods of the desizing method of Embodiment 9, except in that different bath ratios are controlled.

Three parallel tests are performed for each group.

After desizing, the fabrics of each group are individually dried in a 105 °C oven to constant weight, then the fabrics are taken out and placed in a dryer to cool to room temperature, and then a weight is accurately weighed for counting it as G'. Table 6 Test results: Table 6 Test for properties of different bath ratios Bath ratio Whiteness Standard | Desizing rate Standard apes sn || Experimental 4.89 0.15 94.27 0.05 rw | Experimental 4.48 0.04 92.30 0.08 mie Control 4.10 0.12 90.12 0.11 pmte Control 3.10 0.03 88.45 0.15 Er Embodiment 15: Test for properties of reaction temperature of polyester-cotton blended fabrics during desizing Different parameters of reaction temperatures are selected for testing in properties of desizing: Grouping: Control group 1: reaction temperature of 95°C Control group 2: reaction temperature of 110 °C Experimental group 1: reaction temperature of 100°C Experimental group 2: reaction temperature of 105 °C Method: Tests are performed for desizing on above-mentioned control groups and experimental groups according to the parameters and methods of the desizing method of Embodiment 9, except in that different reaction temperatures are controlled.

Three parallel tests are performed for each group.

After desizing, the fabrics of each group are individually dried in a 105 °C oven to constant weight, then the fabrics are taken out and placed in a dryer to cool to room temperature, and then a weight is accurately weighed for counting it as G’. Table 7 Test results: Table 7 Test for properties of different reaction temperatures

Temperature | Whiteness Standard | Desizing rate Standard (°C) improvement | deviation (%) deviation (Yo) Experimental 4.89 0.15 94.27 0.05 me Experimental 4.48 0.01 90.24 0.16 mees EE Control 2.69 0.06 80.32 0.05 men | Control 3.52 0.05 85.82 0.12 meen) EE Embodiment 16: Test for properties of reaction time of polyester-cotton blended fabrics during desizing Different parameters of reaction time are selected for testing in properties of desizing: Grouping: Control group 1: reaction temperature of 20min Control group 2: reaction temperature of 50min Experimental group 1: reaction temperature of 30min Experimental group 2: reaction temperature of 40min Method: Tests are performed for desizing on above-mentioned control groups and experimental groups according to the parameters and methods of the desizing method of Embodiment 9, except in that different reaction time are controlled.

Three parallel tests are performed for each group.

After desizing, the fabrics of each group are individually dried in a 105 °C oven to constant weight, then the fabrics are taken out and placed in a dryer to cool to room temperature, and then a weight is accurately weighed for counting it as CG’.

Table 8 Test results: Table 8 Test for properties of different reaction time Time (min) Whiteness Standard | Desizing | Standard deviation improvement deviation | rate (%) (%) Embodiment 17: Environment-friendly desizing method for fabric preparation of desizing fluid: adding sophorolipid to a sodium hydroxide solution having a concentration of 8-16 g/L to obtain a desizing fluid, and controlling a final concentration of sophorolipid in the desizing fluid to 0.5-3g/L; the desizing method includes steps of performing desizing reaction, washing and drying in sequence for the fabric. wherein during the desizing reaction, the fabric is immersed in a desizing fluid.

The desizing process is a conventional desizing method in the industry.

Compared with JFC-E and high-efficiency scouring agent, the sophorolipid in the desizing fluid of the disclosure has a significant desizing effect and whiteness improvement.

Comparison between the sophorolipid and JFC-E: the chemical oxygen demand (COD) of 1g/L. sophorolipid is 1655mg/L, while the COD of the same concentration of JFC-E is as high as

2107mg/L, indicating obviously that the sophorolipid has a smaller impact on the ecological environment and is more environmentally friendly than JFC-E.

When a ratio of BOD to COD is greater than 0.3, the biodegradability is good.

The BOD/COD of sophorolipid is 0.44, while the BOD/COD of JFC-E is 0.28, indicating that the biodegradability of sophorolipid is more significant.

The sophorolipid may reduce the surface tension of water to 33.11 mN/m, indicating that the sophorolipid has excellent osmotic wetting properties.

Adding the sophorolipid to Ive may increase the absorption, wetting and penetration of cotton fibers, and help emulsify and disperse the wax and oil contamed m cotton fibers.

Embodiment 18: Environment-friendly desizing method for fabric

A desizing reaction is performed for a pure cotton fabric, wherein a desizing fluid in the desizing reaction is used to desize the fabric, and the desizing fluid comprises lye and sophorolipid.

Embodiment 19: Environment-friendly desizing method for fabric

[0040] A desizing reaction is performed for a polyester-cotton blended fabric, wherein a desizing fluid in the desizing reaction is used to desize the fabric, and the desizing fluid comprises lye and sophorolipid.

Claims

Conclusions

1. Method for environmentally friendly de-sizing of fabric. comprising conducting a de-sizing reaction, wherein a de-sizing liquid is used to de-size the tissue, and the de-sizing solution comprises caustic and sophorolipid.

A method of environmentally friendly fabric de-sizing according to claim 1, characterized in that the de-sizing method further comprises also the steps of washing and drying. and that the de-sizing solution is composed of: sodium hydroxide 8-16g / L, sophorolipid 0.5-3g / L and further water.

The environmentally friendly tissue de-sizing method of claim 1, characterized in that: the de-sizing method comprises the steps of (1) Preparing the de-sizing solution: adding sophorolipid to the sodium hydroxide solution with a concentration of 8-16g / L to obtain a de-sizing solution and control a final concentration of sophorolipid in the de-sizing solution to 0.5-3g / L; (2) De-sizing reaction: immersing the tissue in the de-sizing solution, controlling the bath ratio at 1: 35-1: 60 and a reaction time at 30-50min, and the reaction temperature at 95-105 ° C; (3) Washing: washing the fabric obtained in step (2) until the washing liquid is neutral; (4) Drying the fabric obtained in step (3)

An environmentally friendly fabric de-sizing method according to claim 3, characterized therein: the washing in step (3) comprises: washing the fabric obtained in step (2) with different temperature gradients of 80-90 ° C and 50-70 ° C and then wash with cold water until the washing liquid is neutral.

The environmentally friendly fabric de-sizing method of claim 2, characterized therein: wherein the fabric is a pure cotton or a cotton-polyester blend fabric.

The environmentally friendly fabric de-sizing method of claim 5, characterized in that: the de-sizing method is for pure cotton fabric, and comprises:

(1) Prepare the de-sizing solution: sophorolipid is added into the sodium hydroxide solution at a concentration of 8-159 / L to obtain a de-sizing solution and control the final concentration of sophorolipid in the de-sizing solution to 0.5-3g / L: (2) De-sizing reaction: immersing the fabric in the above de-sizing solution, controlling the bath ratio at 1:40-1: 60, the reaction time at 30-50min , and the reaction temperature at 95-105 ° C; (3) Washing: washing the fabric obtained in step (2), is washed with different temperature gradients of 80-90 ° C and 50-60 ° C and finally washed with cold water until the washing liquid is neutral; (4) drying the water-washed fabric obtained in step (3).

An environmentally friendly fabric de-sizing method according to claim 5, characterized in that: the de-sizing method of said cotton-polyester blend comprises the steps of: (1) Preparing the de-sizing solution: adding sophorolipid to the sodium hydroxide solution at a concentration of 10-16g / L to obtain a de-sizing solution and adjust the final concentration of sophorolipid in this de-sizing solution to 0.5-29 / L: (2) The -sizing reaction: immersing the fabric in the de-sizing solution, and adjusting the bath ratio at 1:35 - 1:50, the reaction time at 30 - 40min, and the reaction temperature at 100-105 ° C :( 3) Washing: washing the fabric obtained in step (2), with different temperature gradients of 80-90 ° C and 60-70 ° C and finally washing with cold water until the washing solution is neutral; (4) drying the water-washed fabric from step (3)