Cashmere low-temperature dyeing process based on enzyme treatment

Abstract

The invention discloses a cashmere low-temperature dyeing process based on enzyme treatment. The process comprises cashmere fiber pretreatment, first enzyme treatment, second enzyme treatment, low-temperature dyeing and post-treatment. Putting the cashmere fibers into a compound enzyme treatment solution for treatment; the compound enzyme treatment liquid contains keratinase, ligninase, pectinase, laccase, a penetrant and water; the cashmere is subjected to mild treatment by compounding a plurality of proteases, and a scale layer is effectively modified on the premise of not damaging a fiber main body, so that high-quality dyeing under medium and low temperature conditions is realized, the dyeing temperature is reduced from 100 DEG C to 60-75 DEG C, and the energy consumption is reduced. The enzyme pretreatment provides more channels and dyeing seats for the dye, the dye uptake is obviously improved, and the color fastness reaches grade 4 or above. The use of strong acid and a large amount of inorganic salt is avoided, the COD (Chemical Oxygen Demand) and salt content in the wastewater are reduced, and the sewage treatment pressure is reduced. And the biological enzyme is biodegradable, so that the environmental load is small.

Description

TECHNICAL FIELD

[0001] The application relates to a cashmere low-temperature dyeing process based on enzyme treatment and belongs to the technical field of cashmere dyeing. BACKGROUND

[0002] Cashmere fiber is known as the "soft gold" due to its softness, lightness and excellent warmth retention. However, the dense scale layer on the surface of cashmere fiber greatly hinders the diffusion of dye molecules into the fiber interior due to its hydrophobicity and chemical inertness. The traditional cashmere dyeing process is usually carried out at a high temperature close to the boiling point (98-100 DEG C) and in a strong acid (pH=3-4) condition, and a large amount of sodium sulfate is used as a dyeing agent.

[0003] The traditional process has many disadvantages: 1) high energy consumption: maintaining a near-boiling temperature requires a large amount of energy consumption; 2) fiber damage: high temperature and strong acid conditions can hydrolyze protein macromolecules, resulting in decreased cashmere fiber strength, yellowing and rough hand feeling; 3) environmental pollution: a large amount of inorganic salts and acidic substances used in the process increase the burden and difficulty of wastewater treatment.

[0004] In order to solve the above problems, some low-temperature dyeing technologies have been explored in the industry, such as using organic solvents, urea or special synthetic auxiliaries to swell the fiber. However, these methods are often costly or introduce new environmental problems. Protease can be used for surface treatment of cashmere fiber, but single protease treatment can result in incomplete surface treatment of cashmere fiber, affecting the subsequent dyeing effect. How to design a cashmere low-temperature dyeing process based on enzyme treatment, which can significantly reduce the dyeing temperature. SUMMARY

[0005] The purpose of the present application is to provide a cashmere low-temperature dyeing process based on enzyme treatment, which can realize high-quality dyeing under medium and low temperature conditions by compounding multiple proteases for mild pretreatment of cashmere fiber.

[0006] To solve the above technical problems, the purpose of the present application is achieved as follows: The application relates to a cashmere low-temperature dyeing process based on enzyme treatment, which comprises the following steps: S1, cashmere fiber pretreatment: cashmere fiber is ultrasonically cleaned with a pretreatment liquid at 40-45 DEG C for 20-30 minutes, rinsed with clean water to neutral, and then dehydrated to a water content of 60%-70% for standby; the pretreatment liquid comprises a detergent, hydrogen peroxide and water; S2, first enzyme treatment: the cashmere fiber treated in the above step is placed in a composite enzyme treatment liquid for treatment, the composite enzyme treatment liquid has a pH value of 7.5-8.5 and a temperature of 50-60 DEG C, and the treatment time is 30-90 minutes; then the temperature is raised to 85-90 DEG C for 5-10 minutes for enzyme inactivation; The complex enzyme treatment liquid contains keratinase, ligninase, pectinase, laccase, penetrant and water; S3, second enzyme treatment: after the previous step, adjust the pH value to 6.8-7.2, add 3-5 g / L of serratia peptidase, the temperature is 50-60℃, the treatment time is 15-20 minutes, then increase the temperature to 85-90℃ for 5-10 minutes, then wash with water to neutral, and dehydrate to 50-60% of moisture content; S4, low temperature dyeing: place the cashmere fiber treated in the previous step in the dyeing liquid, increase the temperature to 60-75℃ at a rate of 1-2℃ / min, and keep the temperature for 30-60 minutes of dyeing, add glacial acetic acid to adjust the pH to 3.5-4.0 10-15 minutes before dyeing; the dyeing liquid includes dye, low temperature dyeing auxiliary agent, penetrant and water; S5, post-treatment: after dyeing, perform fixation treatment, and finally dry.

[0007] On the basis of the above scheme and as a preferred scheme of the above scheme: the penetrant is penetrant JFC.

[0008] On the basis of the above scheme and as a preferred scheme of the above scheme: the amount of keratinase in the complex enzyme treatment liquid is 2-3 g / L, the amount of ligninase is 0.5-0.8 g / L, the amount of pectinase is 1.5-2 g / L, and the amount of laccase is 1.0-1.5 g / L.

[0009] On the basis of the above scheme and as a preferred scheme of the above scheme: the dye is acid dye or reactive dye.

[0010] On the basis of the above scheme and as a preferred scheme of the above scheme: the low temperature dyeing auxiliary agent is a complex of zwitterionic surfactant and wool protective agent, and the total amount is 0.5-1% of the weight of cashmere fiber.

[0011] On the basis of the above scheme and as a preferred scheme of the above scheme: the zwitterionic surfactant is dodecyl dimethyl betaine, and the wool protective agent is fatty alcohol polyoxyethylene ether.

[0012] On the basis of the above scheme and as a preferred scheme of the above scheme: the bath ratio in step S1 cashmere pretreatment is 1:5-8; the bath ratio in step S2 first enzyme treatment is 1:3-5; the bath ratio in step S3 second enzyme treatment is 1:3-5; and the bath ratio in step S4 low temperature dyeing is 1:10-15.

[0013] The application has the advantages that the low-temperature dyeing process for cashmere based on enzyme treatment provided by the application uses multiple protein enzymes to mildly treat cashmere, effectively modifies the scale layer without damaging the main body of the fiber, and thus realizes high-quality dyeing under low-temperature conditions, with the dyeing temperature reduced from 100 DEG C to 60-75 DEG C and the energy consumption reduced. The enzyme pretreatment provides more channels and dye sites for dyes, significantly improves the dye-uptake rate, and makes the color fastness reach level 4 or above. The use of strong acid and a large amount of inorganic salt is avoided, the COD and salt content in the wastewater are reduced, and the pressure on sewage treatment is reduced. The biological enzyme itself is biodegradable and has small environmental load. DETAILED DESCRIPTION

[0014] The application will be further described below in combination with specific examples.

[0015] The low-temperature dyeing process for cashmere based on enzyme treatment provided by the application comprises the following steps. S1, cashmere fiber pretreatment: cashmere fibers are ultrasonically cleaned in a pretreatment liquid at 40-45 DEG C for 20-30 minutes, rinsed with clean water until neutral, and then dehydrated to a water content of 60-70%, for standby; the pretreatment liquid comprises a detergent, hydrogen peroxide and water.

[0016] S2, first enzyme treatment: the cashmere fibers treated in the previous step are treated in a composite enzyme treatment liquid, the pH value of the composite enzyme treatment liquid is 7.5-8.5, the temperature is 50-60 DEG C, and the treatment time is 30-90 minutes; then the temperature is increased to 85-90 DEG C for 5-10 minutes for enzyme inactivation.

[0017] The composite enzyme treatment liquid contains keratinase, ligninase, pectinase, laccase, a penetrating agent and water.

[0018] S3, second enzyme treatment: after the previous step, the pH value is adjusted to 6.8-7.2, 3-5 g / L of serratia peptidase is added, the temperature is 50-60 DEG C, the treatment time is 15-20 minutes, the temperature is then increased to 85-90 DEG C for 5-10 minutes, and then the cashmere fibers are rinsed with water until neutral and dehydrated to a water content of 50-60%.

[0019] S4, low-temperature dyeing: the cashmere fibers treated in the previous step are placed in a dyeing liquid, the temperature is increased to 60-75 DEG C at a rate of 1-2 DEG C / min, and the cashmere fibers are dyed for 30-60 minutes, and ice acetic acid is added to adjust the pH value to 3.5-4.0 10-15 minutes before dyeing; the dyeing liquid comprises a dye, a low-temperature dyeing aid, a penetrating agent and water.

[0020] S5, post-treatment: after dyeing, fixation treatment is performed, and finally drying is performed.

[0021] Example 1 In the present embodiment, the following specific parameters are used: in step S1, 100 g of cashmere fibers are used, the bath ratio is set to 1:6, the amount of detergent in the pretreatment solution is 2 g / L, the amount of hydrogen peroxide is 3 g / L, ultrasonic cleaning is performed at 45°C for 25 minutes, the fibers are rinsed with clean water until neutral, and then dehydrated to a moisture content of 65%.

[0022] In step S2, the bath ratio is 1:4, the pH value of the composite enzyme treatment solution is adjusted to 8.0, the temperature is controlled at 55°C, the amounts of keratinase, ligninase, pectinase, laccase, and penetrant JFC are 2.5 g / L, 0.6 g / L, 1.8 g / L, 1.2 g / L, and 1 g / L, respectively, and the treatment is performed for 60 minutes, after which the temperature is raised to 88°C for 8 minutes to inactivate the enzymes.

[0023] In step S3, the bath ratio is also 1:4, the pH value is adjusted to 7.0, 4 g / L of serratia peptidase is added, the treatment is performed at 55°C for 18 minutes, and then the temperature is raised to 88°C for 8 minutes, after which the fibers are rinsed with water until neutral and then dehydrated to a moisture content of 55%.

[0024] In step S4, the bath ratio is set to 1:12, 2% of the mass of the cashmere fibers is used as an acid pink dye, a low-temperature dyeing aid is a compound prepared by compounding dodecyl dimethyl betaine and fatty alcohol polyoxyethylene ether at a mass ratio of 1:1, the total amount of the low-temperature dyeing aid is 0.5% of the mass of the cashmere fibers, the amount of penetrant JFC is 1 g / L, the temperature is raised to 70°C at a rate of 1.5°C / min, and the dyeing is performed for 45 minutes, during which 12 minutes before the dyeing, glacial acetic acid is added to adjust the pH value to 3.8.

[0025] Finally, post-treatment is performed in step S5, and after the fixation treatment, the fibers are dried. The cashmere fibers are added to a fixation treatment solution at a bath ratio of 1:5, the fixation treatment solution contains 1.5% of a cationic fixing agent GY, the fibers are stirred at 65°C and 40 r / min for 30 minutes, rinsed with clean water at 40°C until there is no floating color, added to a treatment solution containing 0.2% of a softener, soaked at 45°C for 20 minutes, and then dehydrated and dried at 60°C.

[0026] After the treatment, the cashmere fibers have good dyeing effects, the dye uptake is significantly improved, the color fastness reaches level 4 or above, the fibers have small damage and soft hand feeling, the energy consumption is reduced, and the pressure of wastewater treatment is also significantly reduced, fully reflecting the advantages of the process of the present application. The K / S value is 18.7, and the breaking strength is 5.8 cN / tex, which is decreased by 8% compared with the original fibers.

[0027] Example Two In this embodiment, the following specific parameters are used: in step S1, 120 g of cashmere fibers are used, the bath ratio is set to 1:7, the detergent dosage in the pretreatment solution is 2.2 g / L, the hydrogen peroxide dosage is 3.2 g / L, ultrasonic cleaning is performed at 42℃ for 28 minutes, and then the fibers are rinsed with clean water until neutral, and then dehydrated to a moisture content of 68%.

[0028] In step S2, the bath ratio is 1:3.5, the pH value of the composite enzyme treatment solution is adjusted to 8.2, the temperature is controlled at 58℃, the keratinase dosage is 2.8 g / L, the ligninase dosage is 0.7 g / L, the pectinase dosage is 1.9 g / L, the laccase dosage is 1.4 g / L, and the penetrant JFC dosage is 1.2 g / L. After 70 minutes of treatment, the temperature is raised to 89℃ for 7 minutes to inactivate the enzyme.

[0029] In step S3, the bath ratio is also 1:3.5, the pH value is adjusted to 7.1, 4.5 g / L of serratia peptidase is added, and the treatment is carried out at 58℃ for 16 minutes, and then the temperature is raised to 89℃ for 7 minutes. After rinsing with water until neutral, the fibers are dehydrated to a moisture content of 53%.

[0030] In step S4, the bath ratio is set to 1:13, and 2.2% of active blue dye based on the weight of the cashmere is used in the dyeing solution. The low-temperature dyeing aid is a complex prepared by compounding dodecyl dimethyl betaine and fatty alcohol polyoxyethylene ether at a mass ratio of 1:1.2. The total dosage of the low-temperature dyeing aid is 0.7% of the weight of the cashmere fibers, and the penetrant JFC dosage is 1.2 g / L. The temperature is raised to 72℃ at a rate of 1.8℃ / min, and the dyeing is carried out at this temperature for 50 minutes. 13 minutes before dyeing, glacial acetic acid is added to adjust the pH to 3.9.

[0031] Finally, the post-treatment of step S5 is carried out, and the cashmere fibers are dried after the fixation treatment. According to the bath ratio of 1:4.5, the cashmere fibers are added to the fixation treatment solution, which contains 1.8% of cationic fixing agent GY. The treatment is carried out at 68℃ with stirring at 45 r / min for 32 minutes, and then rinsed with clean water at 42℃ until there is no floating color. Then, the fibers are added to the treatment solution containing 0.25% of softener, and soaked at 48℃ for 22 minutes. After dehydration, the fibers are dried at 62℃.

[0032] After the treatment by the process, the cashmere dyeing has uniform and full color, the dye uptake is further improved, the color fastness reaches level 4-5, the fiber strength is well maintained, the hand feeling is smoother, the energy consumption is greatly reduced compared to the traditional process, and the pollutant content in the wastewater discharge is significantly reduced, further verifying the effectiveness and superiority of the process in practical application. The K / S value is 19.4, and the breaking strength is 5.6 cN / tex.

[0033] The preferred embodiments of the present application have been described above in detail. It should be understood that modifications and variations to the preferred embodiments could be made by those skilled in the art in light of the teachings above. It is therefore contemplated that the application can encompass other variations and modifications that fall within the scope of the claims.

Claims

1. A low-temperature dyeing process for cashmere based on enzyme treatment, characterized in that, Includes the following steps: S1. Cashmere fiber pretreatment: The cashmere fibers are ultrasonically cleaned with a pretreatment solution at 40-45℃ for 20-30 minutes, rinsed with clean water until neutral, and then dehydrated to a moisture content of 60%-70% for later use; the pretreatment solution includes detergent, hydrogen peroxide and water. S2. First enzyme treatment: Place the cashmere fibers treated in the previous step into a compound enzyme treatment solution for treatment. The pH value of the compound enzyme treatment solution is 7.5-8.5, the temperature is 50-60℃, and the treatment time is 30-90 minutes. Then raise the temperature to 85-90℃ and keep it at that temperature for 5-10 minutes to inactivate the enzyme. The compound enzyme treatment solution contains keratinase, ligninase, pectinase, laccase, penetrant and water; S3. Second Enzyme Treatment: After the previous step, adjust the pH to 6.8-7.2, add 3-5 g / L of serrata peptide enzyme, maintain the temperature at 50-60℃ for 15-20 minutes, then raise the temperature to 85-90℃ and keep it at that temperature for 5-10 minutes. Wash with water until neutral, and dehydrate to a moisture content of 50-60%. S4. Low-temperature dyeing: Place the cashmere fibers treated in the previous step into the dye bath, heat to 60-75℃ at a rate of 1-2℃ / min, and dye at this temperature for 30-60 minutes. Add glacial acetic acid 10-15 minutes before dyeing to adjust the pH to 3.5-4.

0. The dye bath includes dye, low-temperature dyeing auxiliaries, penetrant and water. S5. Post-treatment: After dyeing, fix the color and then dry.

2. The low-temperature dyeing process for cashmere based on enzyme treatment according to claim 1, characterized in that, The penetrant is penetrant JFC.

3. The low-temperature dyeing process for cashmere based on enzyme treatment according to claim 1, characterized in that, The amount of keratinase in the compound enzyme treatment solution is 2-3 g / L, the amount of ligninase is 0.5-0.8 g / L, the amount of pectinase is 1.5-2 g / L, and the amount of laccase is 1.0-1.5 g / L.

4. The low-temperature dyeing process for cashmere based on enzyme treatment according to claim 1, characterized in that, The dye is an acid dye or a reactive dye.

5. The low-temperature dyeing process for cashmere based on enzyme treatment according to claim 1, characterized in that, The low-temperature dyeing auxiliary is a compound of amphoteric surfactant and wool protectant, and its total amount accounts for 0.5-1% of the weight of cashmere fibers.

6. The low-temperature dyeing process for cashmere based on enzyme treatment according to claim 5, characterized in that, The zwitterionic surfactant is dodecyl dimethyl betaine, and the wool protectant is fatty alcohol polyoxyethylene ether.

7. The low-temperature dyeing process for cashmere based on enzyme treatment according to claim 1, characterized in that, The liquor ratio for cashmere pretreatment in step S1 is 1:5-8; the liquor ratio for the first enzyme treatment in step S2 is 1:3-5; the liquor ratio for the second enzyme treatment in step S3 is 1:3-5; and the liquor ratio for low-temperature staining in step S4 is 1:10-15.