Flexible treating agent for silk-flax blended fabric

Abstract

The invention relates to the technical field of fabric finishing, in particular to a flexible treating agent for silk-flax blended fabric. The prepared flexible treating agent is used for treating fabric, and the problems that linen fabric is poor in flexibility and poor in washing resistance are solved. The copolyester material is prepared through esterification and copolymerization of alcohol and acid, and is used for preparing the flexible treating agent; the fabric is subjected to surface treatment, ultrasonic-assisted enzyme treatment, illumination-matched bleaching, impregnation and activation, and finally, a flexible treatment agent is used for treatment. A flexible film is formed on the surface of the finally obtained flexible silk-flax blended fabric, the flexibility and hand feeling are greatly improved, and due to the fact that all the components are stably combined, the washing resistance is excellent.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fabric finishing, in particular to a flexible treatment agent for silk-linen blended fabric. BACKGROUND

[0002] Silk-linen blended fabric is favored for its advantages of both fibers: silk gives the fabric a soft and smooth touch and elegant luster, while linen contributes excellent air permeability, moisture absorption and stable shape, making it widely used in high-end clothing, home textiles and other fields. However, this blended fabric has obvious performance contradictions during processing and use: the molecular structure of linen fiber contains a large number of hydroxyl groups, with strong intermolecular forces, resulting in high fiber rigidity and low elongation at break, which can cause the overall fabric to feel stiff and have poor drape after blending with silk due to the difference in fiber friction coefficient; at the same time, the lignin and pectin components in linen fiber can remain during dyeing and finishing, further exacerbating the roughness of the fabric, and after multiple washes, problems such as linting and snagging can occur, seriously affecting the wear experience and durability of the product. Existing flexible treatment technologies for blended fabrics mostly use traditional chemical softeners, such as quaternary ammonium salt cationic surfactants or silicone emulsions. However, these treatments have obvious limitations: cationic softeners can temporarily improve hand feel, but they can reduce the moisture absorption of the fabric and have poor compatibility with anionic dyes, leading to uneven dyeing; silicone-based treatments can improve smoothness, but long-term use can form a silicon film on the fabric surface that is difficult to degrade, affecting air permeability, and yellowing can occur during high-temperature setting. In addition, the silk fibroin protein in silk fibers is prone to hydrolysis in an alkaline treatment environment, and linen fibers are sensitive to acid, which poses strict requirements on the pH stability of the treatment agent, and traditional treatments cannot meet the chemical stability of both fibers. With the increasing demand for comfort and environmental friendliness of textiles, developing a flexible treatment agent that can adapt to the characteristics of both silk and linen fibers, with excellent softness, washability and environmental friendliness, has become a technical problem that needs to be solved in the industry. An ideal treatment agent should have selective adsorption ability, which can form hydrogen bonds with the amide groups of silk and react with the hydroxyl groups of linen through functional groups to build a flexible molecular layer on the fiber surface, while avoiding damage to the inherent properties of both fibers.

[0003] Therefore, a flexible treatment agent for silk-linen blended fabric is proposed. SUMMARY

[0004] The present application aims to provide a flexible treatment agent for silk-flax blended fabric. The copolyester material is prepared by esterification and copolymerization of alcohol and acid, and is used to prepare the flexible treatment agent. The fabric is treated by surface treatment, ultrasonic-assisted enzyme treatment, light bleaching, impregnation and activation, and finally treated by the flexible treatment agent. The flexible silk-flax blended fabric is finally obtained, and a flexible film is formed on the surface of the fabric, which greatly improves the flexibility and hand feeling. In addition, the components are combined stably, and the fabric has excellent washing resistance.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions: The present application provides a flexible treatment agent for silk-flax blended fabric. The preparation raw materials of the flexible treatment agent include light white oil, ester-based quaternary ammonium salt, temperature-sensitive polymer, copolyester material, sodium benzoate and water. The treatment agent used in combination with the flexible treatment agent includes dispersant, soda ash, disodium ethylenediaminetetraacetate, pectinase, cellulase, hydrogen peroxide, sodium perborate, sodium chlorite and sulfuric acid. The copolyester material is obtained by esterification and polycondensation reactions.

[0006] The silk-flax blended fabric is a product of the present company, which is 55% flax and 45% silk, and has a weight of 200g / m². The flax degumming enzyme is purchased from Shanghai Kangdien Biological Technology Co., Ltd. The solid sodium chlorite is purchased from Jinan Zhengkang Chemical Co., Ltd. The dispersant is purchased from Shanghai Jingshi Textile Technology Co., Ltd. The solvent oil-light white oil is purchased from Hu Zhou Deman Lubricating Oil Co., Ltd. The sodium benzoate has a CAS of 532-32-1. The disodium ethylenediaminetetraacetate has a CAS of 139-33-3. The soda ash is purchased from Wujing Heng Xu Chemical Co., Ltd. The hydrogen peroxide is purchased from Wujing Long Yue Chemical Trading Department. The sebacic acid has a CAS of 111-20-6. The titanium-based catalyst titanium tetraisopropoxide has a CAS of 546-68-9. The isosorbide has a CAS of 652-67-5. The ethylene glycol has a CAS of 107-21-1. The nano titanium dioxide is anatase type, and has a particle size of 20-30nm.

[0007] Preferably, the esterification reaction is as follows: the sebacic acid, isosorbide and titanium tetraisopropoxide are mixed, nitrogen is charged in several times, the pressure is released, and then the temperature is raised. The product A is obtained by stirring until the water output no longer changes. The sebacic acid, ethylene glycol and titanium tetraisopropoxide are mixed, nitrogen is charged in several times, the pressure is released, and then the temperature is raised. The product B is obtained by stirring until the water output no longer changes.

[0008] Preferably, the polycondensation reaction is as follows: the product A and the product B are mixed, a catalyst is added, the vacuum pump is started after the temperature is raised, the pressure is reduced, and the polycondensation reaction is carried out. Nitrogen is charged after the reaction is completed, and the material is discharged under normal pressure and water cooling.

[0009] Preferably, the method of using the flexible treating agent is as follows: the activated silk-linen blended fabric is immersed in the flexible treating agent, and then is subjected to one-dip-one-nip, pre-drying and setting treatment at room temperature; the copolyester material is present in the flexible treating agent in a dispersed state.

[0010] Preferably, the activated silk-linen blended fabric is obtained by immersing the bleached silk-linen blended fabric in an activation treating solution, stirring, neutralizing and cold water washing; the raw materials for preparing the activation treating solution include sodium chlorite and sulfuric acid.

[0011] Preferably, the bleached silk-linen blended fabric is obtained by immersing the enzyme-treated silk-linen blended fabric in a bleaching solution, acid-base adjustment, temperature treatment, light irradiation and water washing.

[0012] Preferably, the enzyme-treated silk-linen blended fabric is obtained by immersing the surface-treated silk-linen blended fabric in an enzyme solution, ultrasonic treatment after adjusting the pH with glacial acetic acid and water washing.

[0013] Preferably, the surface-treated silk-linen blended fabric is obtained by immersing the silk-linen blended fabric after low-temperature plasma pretreatment in a mixed solution and then rinsing; the raw materials for preparing the mixed solution include dispersant, sodium carbonate and ethylenediaminetetraacetic acid disodium salt.

[0014] Compared with the prior art, the present application has the following beneficial effects: 1. The low-temperature plasma pretreatment etches the fiber surface, increases the hydroxyl and carboxyl groups to improve the permeability of the enzyme solution, promotes the diffusion of the enzyme by the cavitation effect of the ultrasonic wave, and makes the pectinase and cellulase degrade pectin efficiently; the chitosan is used to stabilize the enzyme activity and lubricate the fiber; the sodium chlorite is used to release chlorous acid under the condition of sulfuric acid and a set pH, oxidize the residual lignin, activate the fiber surface to enhance the adsorption of the softener, and realize the synergy of each link through the optimized treatment process; the lignin and pectin are completely removed, the softness of the silk-linen blended fabric is significantly improved through the synergy of the flexible fiber and the intelligent softener, and the hand feeling is greatly improved.

[0015] 2. The oxygen plasma etches the fiber surface, which is beneficial to the permeation of the enzyme solution and the bleaching solution; the ultrasonic wave is used to promote the degradation of pectin by the pectinase and cellulase, and remove the pigment carrier; the nano titanium dioxide is used to generate active oxygen by catalyzing H2O2 and sodium perborate under visible light, and efficiently oxidize the pigment; the sodium chlorite is used to oxidize the residual lignin, and further improve the whiteness; the flexible agent has no obvious influence on the whiteness of the fabric, and the sodium benzoate contained therein can prevent the growth of microorganisms and the deposition of pigment, thereby indirectly maintaining the stability of the whiteness; the pigment and lignin are effectively removed, the fabric has high whiteness and stability.

[0016] 3. The copolyester material is added in the flexible agent, which is combined with the fabric fiber through physical entanglement and mechanical anchoring, the PNIPAM is treated to form a flexible film on the surface of the fabric and is adsorbed or entangled with the fiber, the ester group quaternary ammonium salt enhances the adsorption, and the washing resistance and mechanical properties of the fabric are improved.

[0017] 4. The plasma pretreatment enhances the hydrophilicity of the fiber to reduce the amount of enzyme liquid and bleaching liquid, the ultrasonic-assisted enzyme treatment improves the efficiency to reduce the organic matter residue, the nano titanium dioxide catalyzes to reduce the amount of bleaching agent, the sodium chlorite oxidizes the by-product, and the biodegradability of each component is good; the above processes are coordinated to realize the good washing resistance and mechanical properties of the fabric, and the COD content in the treatment wastewater meets the emission standard. BRIEF DESCRIPTION OF DRAWINGS

[0018] Fig. 1 It is the FTIR result graph of the copolyester material of the application; Fig. 2 It is the softness test result graph of the application examples 1-5 and the comparative examples 1-6 and the comparative examples 8-9. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0020] Please refer to Figs. 1-2 The application provides a flexible treatment agent for silk-flax blended fabric, and the technical scheme is as follows: Preparation example 1 (preparation of copolyester material) Check the vacuum degree of the polymerization kettle ≤-0.095 MPa to ensure the sealing property; accurately weigh 404.5 g of sebacic acid and 138.8 g of isosorbide, add 0.54 g of titanium-based catalyst titanium tetraisopropoxide, stir at 30 ℃ and 50 rpm for 30 min, then fill nitrogen gas in three times, discharge and exhaust, keep 0.1 MPa in the third time, heat to 225 ℃, stir at 100 rpm for 30 min, then increase the speed to 200 rpm, slowly release the pressure through the pressure relief valve when the pressure reaches 0.4 MPa, repeat 3 times, collect 70.5 g of water in 2 h, and the water output no longer changes, to obtain product A; accurately weigh 404.5 g of sebacic acid and 89.3 g of ethylene glycol, add 0.54 g of titanium-based catalyst titanium tetraisopropoxide, and the esterification reaction conditions of product A are the same, and product B is obtained by reaction; Mixing product A and product B, adding 0.27 g of titanium-based catalyst, heating to 260℃, starting the vacuum pump, and reducing the pressure to -100 kPa within 45 min; performing the polycondensation reaction at 275℃ and 40 mmHg for 3.5 h, then charging nitrogen, stopping at 0.1 Mpa for 10 min, and water-cooling to discharge the product to obtain the copolyester; Transferring the copolyester to a vacuum drum oven, increasing the temperature from 40℃ to 95℃ within 3 h, and maintaining the temperature for 15 h for pre-crystallization; increasing the temperature to 135℃ within 3 h, and maintaining the temperature for 15 h to remove the crystallization water; reducing the temperature to 40℃ within 5 h to obtain the copolyester material precursor; performing melt spinning on the precursor, and setting the spinning conditions as follows: the spinneret has 24 holes with a size of 0.3 mm*0.75 mm, the metering pump is 1.2 mL, the rotating speed is 15 r / min, the winding speed is 800 r / min, the hot drawing is performed at 95℃, and the heat setting is performed at 100℃; the superfine copolyester material with a diameter of 10-15 μm is obtained.

[0021] Preparation of Comparative Example 1 Different from Preparation Example 1, the sebacic acid is replaced by an equal molar amount of terephthalic acid, and the amount is 332.3 g; and the other preparation methods remain unchanged.

[0022] Example 1 (Combined with enzyme treatment: improving the hydrophilicity of the fiber surface and enhancing the penetration of the enzyme solution) silk-linen blended fabric is subjected to low-temperature plasma pretreatment, and the specific setting conditions are as follows: the surface of the fabric is treated under the conditions of oxygen atmosphere pressure of 0.1 mbar and power of 150 W for 2 min; after the treatment, the fabric is immersed in a mixed solution, and the ratio of the plasma pretreated fabric to the mixed solution is 1:20; the fabric is washed at 50℃ for 20 min, and the pH is 7.0; the fabric is rinsed twice, and then dried at 100℃ for 5 min to obtain the surface-treated silk-linen blended fabric; the concentrations of the dispersant, sodium silicate, EDTA-2Na, and penetrating agent JFC in the mixed solution are 2 g / L, 1 g / L, 0.5 g / L, and 0.5 g / L, respectively.

[0023] (Synergistic mechanism: ultrasonic wave promotes enzyme penetration, chitosan stabilizes enzyme activity, EDTA-2Na and JFC ensure uniformity) The surface-treated silk-linen blended fabric is immersed in the enzyme solution, with a bath ratio of 1:20, and the pH is adjusted to 5.0 with glacial acetic acid; the concentration of the enzyme solution is 4.5% for the degumming enzyme, 0.5g / L for chitosan (3% acetic acid solution), 2g / L for EDTA-2Na, 1g / L for the dispersing agent, and 0.6g / L for the penetrant JFC; after immersion, ultrasonic waves are started at 30°C, with a power of 40kHz and 200W, and the temperature is increased to 45°C at a rate of 1°C / min, with stirring at 120rpm; the temperature is kept constant for 60min; after the immersion is complete, the enzyme is inactivated by rinsing at 90°C for 10min, washing in hot water at 70°C for 5min, washing in cold water, and drying at 100°C for 5min to obtain the enzyme-treated silk-linen blended fabric; the mass ratio of pectinase to cellulase in the degumming enzyme is 3:1.

[0024] (Synergistic mechanism: photocatalytic generation of active oxygen, gentle removal of residual enzyme treatment impurities) The enzyme-treated silk-linen blended fabric is immersed in the bleaching solution, with a bath ratio of 1:20, and the pH is adjusted to 10.0 with sodium carbonate; the temperature is increased from 40°C to 75°C at a rate of 1.2°C / min, and the fabric is irradiated with visible light from a 100W daylight lamp tube for 50min at a constant temperature, with stirring at 80rpm and adjusting the pH to 9.5 every 15min; the fabric is washed in hot water at 70°C for 5min, and then washed in cold water until it is neutral to obtain the bleached silk-linen blended fabric; the concentration of hydrogen peroxide (35%) in the bleaching solution is 4.5wt%, the concentration of sodium peroxoborate is 2g / L, the concentration of nano-TiO2 is 0.3g / L, the concentration of sodium sulfite is 4g / L, the concentration of EDTA-2Na is 1g / L, and the concentration of the dispersing agent is 1g / L.

[0025] (Synergistic mechanism: removal of residual lignin, activation of fiber surface) The bleached silk-linen blended fabric is immersed in the activation treatment solution, with a bath ratio of 1:20 and a pH of 3.5; the temperature is kept constant at 60°C with stirring at 80rpm for 20min, and then neutralized with 0.5g / L of sodium carbonate; the fabric is washed in hot water at 70°C for 5min, and then washed in cold water until the pH is 7.0 to obtain the activated silk-linen blended fabric; the concentration of solid sodium chlorite in the activation treatment solution is 1.0g / L, the concentration of sulfuric acid is 0.6g / L, and the concentration of the dispersing agent is 1g / L.

[0026] (working mechanism: copolyester material fills the gap between fibers, silicone and PNIPAM form temperature-sensitive flexible film, quaternary ammonium salt enhances antistatic property) The activated silk-linen blended fabric is immersed in the flexible treatment agent at a ratio of 1:15 at room temperature, one dip and one roll, with a pick-up rate of 75%, followed by pre-drying at 100°C for 5 min and setting at 140°C for 45 s to obtain the flexible silk-linen blended fabric. The concentration of light white oil in the flexible treatment agent is 15 wt%, the concentration of ester-based quaternary ammonium salt is 5 wt%, the concentration of PNIPAM is 2.5 wt%, the concentration of copolyester material is 2.0 wt%, and the concentration of sodium benzoate is 15 wt%, and the balance is water; the above raw materials are mixed and high-speed sheared at 3000 rpm for 10 min, and the pH is adjusted to 4.5 with glacial acetic acid to obtain the flexible treatment agent; the copolyester material is obtained by the method of Preparation Example 1.

[0027] Examples 2-5 Different from Example 1, the following preparation conditions are changed, as shown in Table 1.1 and Table 1.2.

[0028] Table 1.1 Flexible treatment method of silk-linen blended fabric

[0029] Table 1.2 Flexible treatment method of silk-linen blended fabric

[0030] Comparative Example Different from Example 4, except for the following preparation conditions, the other preparation methods remain unchanged.

[0031] Comparative Example 1 The copolyester material is replaced by the copolyester material obtained in Preparation Comparative Example 1.

[0032] Comparative Example 2 No copolyester material is added.

[0033] Comparative Example 3 The concentration of copolyester material is 5 wt%.

[0034] Comparative Example 4 No copolyester material, light white oil, PNIPAM and ester-based quaternary ammonium salt are added.

[0035] Comparative Example 5 No low-temperature plasma pretreatment is performed, and the ultrasonic-assisted degumming step is directly performed.

[0036] Comparative Example 6 No ultrasonic treatment is performed during the degumming process.

[0037] Comparative Example 7 No nano-TiO2 is added to the bleaching solution, and no light treatment is performed.

[0038] Comparative Example 8 The bleached silk-linen blended fabric is immersed in the flexible treatment agent for flexible treatment, without activation treatment.

[0039] Comparative Example 9 No softening agent was used.

[0040] Comparative Example 10 No hydrogen peroxide was added in the bleaching solution.

[0041] Experimental Example 1 The flexible silk-linen blended fabric treated above was subjected to softness test, and the specific test method was as follows: according to the standard of GB / T 18318.1-2009 "Determination of bending properties of textile fabrics Part 1: Assessment by the hand feel method", each group of tested fabric was cut into a size of 20 cm x 20 cm, and the test environment temperature was 25℃ and the relative humidity was 65%; a professional group of 5 people conducted blind evaluation on the treated silk-linen blended fabric, a 5-point scoring standard was used, each evaluator independently touched and scored, and the average value of the scores of 5 people was taken, wherein: 5 points: extremely soft, excellent smooth feeling, extremely low fiber friction, and delicate hand feeling.

[0042] 4 points: soft, good smooth feeling, low fiber friction, and relatively delicate hand feeling.

[0043] 3 points: moderate softness, general smooth feeling, moderate fiber friction, and ordinary hand feeling.

[0044] 2 points: relatively hard, rough hand feeling, and relatively high fiber friction.

[0045] 1 point: extremely hard, extremely rough hand feeling, and significant fiber friction. Fig. 2 The test results are shown in Table 2 and Table 3.

[0046] Table 2 Softness test results of Examples 1-5 and Comparative Examples 1-6 and Comparative Examples 8-9

[0047] The flexible treatment agent prepared according to the process of the present application, and the flexible silk-linen blended fabric obtained by the treatment method of the present application, have good softness and obvious hand feeling improvement. Under the conditions of Examples 1-5, the low-temperature plasma pretreatment etches the fiber surface with oxygen plasma, increases the hydroxyl and carboxyl groups, and improves the enzyme liquid permeability; the ultrasonic cavitation effect promotes enzyme diffusion, pectinase and cellulase efficiently degrade pectin, chitosan stabilizes enzyme activity and lubricates fibers; NaClO2 releases ClO2 under the activation of H2SO4 and a set pH, oxidizes residual lignin, activates the fiber surface, and enhances the adsorption of softening agent; the optimized treatment process has high enzyme treatment efficiency, complete removal of lignin and pectin, and the synergistic effect of flexible fibers and intelligent softening agent improves the softness.

[0048] Comparative Example 1 replaces sebacic acid with terephthalic acid, which has a rigid benzene ring structure, significantly reducing the flexibility of the copolyester material, and the lubrication effect between fibers is poor, and the softness decreases; Comparative Example 2 lacks copolyester material, the gap between fibers is not filled, and the smoothness depends on light white oil and PNIPAM, with limited effect, while the copolyester material obtained in Preparation Example 1 has an infrared spectrum as shown in Figure 1. Fig. 1 showing that the 2920 cm -1 corresponds to the asymmetric stretching of sebacic acid-CH2, and 2850 cm -1 corresponds to the symmetric stretching, 1710 cm -1 corresponds to the carboxyl C=O stretching vibration, 1460 cm -1 corresponds to the bending vibration peak of aliphatic-CH2-, 1407 cm -1 The weak absorption peak at 1090 cm -1 corresponds to the strong absorption band, and 972 cm -1 corresponds to the weak absorption band, which corresponds to the symmetric and asymmetric aliphatic ether group caused by the melting furan ring in the isosorbide structure, and there are two strong absorption peaks in 1270-1080 cm -1 , indicating the presence of ester groups in the structure, the infrared results show that the copolyester material is successfully synthesized; the copolyester material does not play a role, and only relies on enzyme treatment and activation to maintain high efficiency, pectin and lignin are completely removed, but the overall flexibility is insufficient; Fig. 2 The results of Comparative Example 3 show that the excess copolyester material in Comparative Example 3 blocks the gap between the fibers, increases the sticky feeling, and reduces the air permeability and hand feeling; Comparative Example 4 lacks a key softening component, and the softness is significantly reduced; Comparative Example 5 has no plasma pretreatment, the fiber surface has poor hydrophilicity, the enzyme solution has reduced permeability, the pectin removal rate is reduced, the subsequent bleaching and activation effect is limited, and the softener is unevenly absorbed; Comparative Examples 5-6 and Comparative Example 8 lack surface treatment, ultrasonic treatment, and activation treatment, and the softness of the fabric is not good; Comparative Example 9 has no soft finishing, and the fiber surface only relies on enzyme treatment and bleaching, and pectin and lignin are partially removed, resulting in a rough hand feeling.

[0049] Experimental Example 2 The flexible silk-linen blended fabric obtained by treating Examples 1-5, Comparative Examples 4-7, and Comparative Example 10 was tested for whiteness, and the specific test method was as follows: The whiteness of the fabric was measured under D65 light source using a CIE whiteness meter, and the specific operation was as follows: The treated silk-linen blended fabric was cut into 20 cm x 20 cm, placed flat to ensure no wrinkles and contamination, the light source was D65 simulated daylight, the temperature was 25°C, and the relative humidity was 65%, and the CIE whiteness value (W_CIE) was recorded, which represents the ability of the fabric to reflect light, and the higher the value, the higher the whiteness.

[0050] Each sample was tested at 5 different positions, and the average value was taken with one decimal place reserved; the final test results are shown in Table 3.

[0051] Table 3 Fabric whiteness test results of Examples 1-5, Comparative Examples 4-7 and Comparative Example 10

[0052] The flexible silk-flax blended fabric obtained by the treatment process and the flexible treatment according to the present application has high whiteness under the conditions of Examples 1-5. In the treatment conditions, the oxygen plasma etches the fiber surface, which is beneficial to the penetration of the enzyme solution and the bleaching solution. The ultrasonic wave promotes the degradation of pectin by pectinase and cellulase, and removes the pigment carrier. The nano-TiO2 catalyzes the generation of active oxygen from H2O2 and sodium perborate under visible light, and efficiently oxidizes the pigment. The sodium chlorite oxidizes the residual lignin, further improving the whiteness. The treatment of the flexible agent has no obvious effect on the whiteness of the fabric.

[0053] Comparative Example 4 lacks the soft component, which has little effect on bleaching, and the whiteness is slightly lower than that of Example 4. Sodium benzoate in the flexible agent acts as a preservative, which can prevent the formation of mold spots or pigment deposition due to microbial growth during storage or subsequent use of the fabric, thereby indirectly maintaining the stability of the whiteness. Comparative Example 5 does not undergo low-temperature plasma pretreatment, and the fiber surface has poor hydrophilicity, which reduces the permeability of the enzyme solution and the bleaching solution, and the pectin removal effect is poor, limiting the bleaching and activation effects, and leaving more pigment and lignin residues. Comparative Example 6 does not undergo ultrasonic treatment, which limits the diffusion of the enzyme and affects the pectin removal effect, leaving high pigment carrier residues, and the bleaching and activation effects are affected by insufficient enzyme treatment, resulting in low lignin removal rate. Comparative Example 7 lacks the oxidation process of the pigment, resulting in a decrease in whiteness. Comparative Example 10 does not contain hydrogen peroxide in the bleaching solution, i.e., it does not undergo effective bleaching, resulting in a significant decrease in whiteness.

[0054] Experimental Example 3 The flexible silk-flax blended fabric obtained by Examples 1-5, Comparative Examples 1-6 and 8-9 was subjected to breaking strength and washing resistance performance tests. The specific test method for breaking strength is as follows: using a strip sample method, referring to GB / T 3923.1-2013 "Textiles - Determination of tensile properties of fabrics - Part 1: determination of breaking force and elongation at break (strip method)", the treated silk-flax blended fabric was cut into a strip-shaped sample with a size of 250mm x 50mm, and was cut along the warp and weft directions respectively, with at least 5 samples in each group. A fabric strength tester was used, with a clamping distance of 100mm and a tensile speed of 100mm / min. The breaking strength of each sample was recorded, and the average value of 5 samples in the warp and weft directions was taken with one decimal place reserved. The specific test method of the water washing resistance performance is as follows: referring to GB / T 3921-2008 Textiles Color Fastness Test Color Fastness to Laundering, the durability of the softener and the fiber treatment is evaluated by simulating multiple water washing through a household washing procedure; the fabric is cut into 10 cm x 10 cm, and 3 pieces are in each group; a standard detergent (ECE non-phosphate detergent, 2 g / L) is used, the bath ratio is 1:50, the temperature is 40°C, the washing time is 30 min, and the A type washing procedure of a household washing machine is used for continuous washing for 20 times, and after each washing, cold water is rinsed, and 40°C drying is performed; after washing, the softness score is performed, the softness retention rate (%) is recorded according to the softness test method of Experimental Example 1, that is, the ratio of the softness score after washing to the initial score, and one decimal place is retained; the final test results are shown in Table 4.

[0055] Table 4: Results of breaking strength and water washing resistance performance of Examples 1-5, Comparative Examples 1-6 and 8-9

[0056] The flexible silk-linen blended fabric obtained by the preparation method of the application has good water washing resistance and good mechanical properties. Under the conditions of Examples 1-5, by adding a copolyester material in the softener, the copolyester is a high molecular polymer formed by polycondensation reaction of sebacic acid, isosorbide and ethylene glycol, which has large molecular weight and stable structure. In the softening treatment, it is filled in the fiber gap of the silk-linen blended fabric, combined with the fabric fibers through physical entanglement and mechanical anchoring, and is not easy to be washed off, the water resistance of the high molecular polymer is strong, and it can still remain in the fabric after multiple washing, and continuously play the role of filling the gap and enhancing the flexibility; and the PNIPAM as a temperature-sensitive high molecular polymer, after high-speed shearing dispersion in the softening agent, a flexible film can be formed on the surface of the fabric through pre-drying and setting process. Its high molecular chain can be physically adsorbed or entangled with the fabric fibers, and the film structure formed has certain mechanical strength and is not easy to be dissolved or peeled off by water; and the added ester quaternary ammonium salt helps to improve the adsorption of the substance on the surface of the fabric, which is not easy to be removed by washing, and can be retained for a long time and play the effect of antistatic and softness enhancement. The water washing resistance effect and mechanical properties of the comparative examples are lower than those of Example 4.

[0057] The specific reasons are as follows: the wash resistance of Comparative Example 1 does not decrease obviously, but the breaking strength decreases, the rigid benzene ring of terephthalic acid reduces the flexibility of the fiber, increases the friction between the fibers, the strength is lost, the rigid fiber has poor ability to absorb the softener, the film layer is easy to peel off after washing, and the wash resistance is relatively decreased; Comparative Example 2 lacks flexible fiber reinforcement, and the strength and wash resistance are decreased; Comparative Example 3 has excess copolyester material to block the gaps between the fibers, increase the rigidity, and lose the strength, and the excess fiber causes the film layer to be thick and heavy, which is easy to peel off after washing, and the wash resistance is poor; Comparative Example 4 lacks a softening component, the fiber surface is rough, the friction is large, the strength is lost, the material adsorption force is extremely low, and the softness rapidly decreases after washing; Comparative Example 5 has no plasma pretreatment, the enzyme liquid has poor permeability, the pectin residue affects the adsorption of the softener, and the wash resistance is reduced; Comparative Example 6 has no ultrasonic wave, the enzyme diffusion is limited, and the pectin removal effect is also affected, thereby reducing the wash resistance and the mechanical properties; Comparative Example 8 does not activate sodium chlorite and sulfuric acid, the lignin residue increases the rigidity of the fiber, and affects the strength and wash resistance; and Comparative Example 9 has no soft finishing, the pectin and lignin residues are left on the fiber surface, the strength is lost, and the hand feeling rapidly deteriorates after washing.

[0058] Experimental Example 4 COD tests were performed on the effluents of the preparation methods of Examples 1-5 and Comparative Example 7, and the specific test method was as follows: according to GB / T 11914-1989, the COD value was calculated by determining the amount of oxidant consumed when the sample was oxidized by potassium dichromate under strong acid conditions; the wastewater discharged during the treatment process of each example and comparative example, including the enzyme treatment, bleaching, activation, and flexible treatment steps, was collected, mixed uniformly, and sampled; 10 mL of the wastewater sample was taken, 98% was added to adjust the pH to <2 in a strong acid environment, 10 mL of 0.025 mol / L potassium dichromate solution was added, sulfuric acid-silver sulfate solution was used as a catalyst, reflux digestion was performed at 150°C for 2 hours to oxidize the organic matter, after cooling, the remaining potassium dichromate was titrated with 0.01 mol / L ferrous ammonium sulfate solution, an o-phenanthroline indicator was added, and the titration volume was recorded to calculate the COD value (mg / L); According to the Textile Dyeing and Finishing Industry Water Pollutant Discharge Standard (GB 4287-2012), the direct discharge COD of textile dyeing and finishing wastewater is ≤100 mg / L, and the test results are summarized in Table 5.

[0059] Table 5: COD content in water discharge

[0060] The flexible silk-linen blended fabric is prepared by the treatment method according to the application, the COD content in the wastewater treated under the conditions of examples 1-5 meets the discharge standard; the hydrophilicity of the fiber is enhanced by the plasma pretreatment, the amount of enzyme solution and bleaching solution is reduced, the discharge of organic matter is reduced, the ultrasonic assisted enzyme treatment efficiently degrades pectin, the amount of organic matter residue is reduced, the ultrasonic wave improves the enzyme efficiency and reduces the amount of enzyme; and the nano-TiO2 catalyzes H2O2 and sodium perborate to generate active oxygen, efficiently oxidizes the pigment and organic impurities, reduces the amount of bleaching agent, NaClO2 releases ClO2, the amount of by-product of oxidized lignin is small, the organic load of the wastewater is low, and the biodegradability of sodium benzoate and low-concentration organic matter, light white oil and PNIPAM is good, the contribution of the COD of the wastewater is small, and the above conditions are synergistic to reduce the COD content in the wastewater. In the comparative example 7, the nano-TiO2 is not added, and the light treatment is not performed, only relying on H2O2 and sodium perborate, the bleaching efficiency is low, the residue of unoxidized pigment and organic matter is high, and in order to achieve part of the whiteness, a higher bleaching agent concentration is required, the amount of organic by-product is increased, and the COD does not meet the discharge standard.

[0061] In summary, the application uses low-temperature plasma pretreatment, ultrasonic assisted enzyme treatment and photocatalytic bleaching, uses sodium chlorite and sulfuric acid for activation, and prepares a copolyester material for a flexible treatment agent, and the fabric treated by the treatment agent has good flexibility and mechanical properties, and the chemical oxygen demand of the wastewater treated according to the process of the application is low.

[0062] Although the embodiments of the application have been shown and described, it is to be understood that for the purpose of the present application, the embodiments can be substantially changed without departing from the spirit and the scope of the present application, the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A flexible treatment for silk-linen blends, characterized in that: The preparation raw materials of the flexible treating agent include light white oil, ester-based quaternary ammonium salt, temperature-sensitive polymer, copolyester material, sodium benzoate and water; the treating agent used in cooperation with the flexible treating agent includes dispersant, soda ash, disodium ethylenediaminetetraacetate, pectinase, cellulase, hydrogen peroxide, sodium perborate, sodium chlorite and sulfuric acid; The copolyester material is obtained by esterification reaction of sebacic acid, isosorbide and ethylene glycol, and polycondensation reaction of product A and product B.

2. A flexible treatment for silk-linen blended fabric as claimed in claim 1, wherein, The esterification reaction is as follows: after the sebacic acid, the isosorbide and titanium tetraisopropoxide are mixed, nitrogen is filled in several times, the pressure is released, and then the temperature is raised, and the stirring reaction is carried out until the water output no longer changes, to obtain the product A; after the sebacic acid, the ethylene glycol and the titanium tetraisopropoxide are mixed, nitrogen is filled in several times, the pressure is released, and then the temperature is raised, and the stirring reaction is carried out until the water output no longer changes, to obtain the product B.

3. The flexible treatment agent for silk-linen blended fabric according to claim 1, characterized in that, The polycondensation reaction is as follows: the product A and the product B are mixed, a catalyst is added, the vacuum pump is started after the temperature is raised, the pressure is reduced, and the polycondensation reaction is carried out, nitrogen is filled in after the reaction is completed, and the material is discharged under normal pressure and water cooling.

4. The flexible treatment agent for silk-linen blended fabric according to claim 1, wherein The use method of the flexible treating agent is as follows: the activated silk-linen blended fabric is immersed in the flexible treating agent, and then pre-drying and qualitative treatment are carried out after one dip and one roll at room temperature; the copolyester material exists in the flexible treating agent in a dispersed state.

5. A flexible treatment for silk-linen blended fabric as claimed in claim 4, wherein: The activated silk-linen blended fabric is obtained by immersing the bleached silk-linen blended fabric in an activation treatment liquid, stirring, neutralizing and cold water washing; the preparation raw materials of the activation treatment liquid include sodium chlorite and sulfuric acid.

6. A flexible treatment for silk-linen blended fabric as claimed in claim 5, wherein: The bleached silk-linen blended fabric is obtained by immersing the enzyme-treated silk-linen blended fabric in a bleaching liquid, adjusting the acid and alkali, and washing with water.

7. A flexible treatment for silk-linen blended fabric as claimed in claim 6, wherein: The enzyme-treated silk-linen blended fabric is obtained by immersing the surface-treated silk-linen blended fabric in an enzyme liquid, adjusting the pH with glacial acetic acid, and then ultrasonic and washing.

8. A flexible treatment for silk-linen blended fabric as claimed in claim 7, wherein: The surface-treated silk-linen blended fabric is obtained by immersing the silk-linen blended fabric in a mixed solution after low-temperature plasma pretreatment; the preparation raw materials of the mixed solution include dispersant, soda ash and disodium ethylenediaminetetraacetate.

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