Salt-free, alkali-free and post-treatment-free method for dyeing silk with high fastness

Abstract

The present invention belongs to the technical field of textile dyeing, specifically to a method for dyeing silk with high fastness, without salt or alkali and requiring no post-treatment. The method comprises the following steps: dissolving a penetrant and a moisturizer in a predetermined amount of water to obtain a first solution; adding a reactive dye to the first solution and stirring until fully dissolved to obtain a dye liquor; adding the prepared dye liquor to a dye trough of a single yarn dyeing device comprising a dye trough and an extruder; then, while winding the silk yarn, the silk yarn is simultaneously passed through the dye trough filled with the dye liquor. The silk yarn, having absorbed the dye liquor, passes through the extruder, allowing the dye liquor to penetrate the yarn interior and simultaneously wind into a loose dyed bobbin, ultimately completing the dyeing process. This method fills a technological gap in the salt- and alkali-free silk dyeing industry, significantly saving the use of dyes and auxiliaries and reducing wastewater discharge.

Description

Technical Field

[0001] The invention belongs to the technical field of textile dyeing, and particularly relates to a high-fastness dyeing method for silk without salt, alkali or post-treatment. Background Art

[0002] Silk is a high-end textile raw material, known as the "Queen of Fibers." It is a natural fiber with long fibers, long enough for weaving. Silk is strong and elastic, delicate and soft, with excellent moisture absorption and tactile properties, and boasts an elegant and beautiful luster. Industrially, it is also used as a material for parachutes, artificial blood vessels, and electrical insulation. my country has become the world's leading silk producer, leading the world in both scale and output. Chinese silk products have long been exported worldwide via the renowned Silk Road, enjoying a high international reputation. China's raw silk production accounts for over 70% of the world's total, and its exports contribute over 80% of global trade.

[0003] The use of silk has a long history and is one of the earliest natural fibers used by humans. In terms of silk dyeing, the traditional method is to use natural dyes to dye silk, but it has always been plagued by the color spectrum and color fastness of natural dyes.

[0004] With the advancement of modern technology, synthetic dyes have emerged. The main synthetic dyes suitable for silk dyeing now include acid dyes, reactive dyes, acid mordant dyes, direct dyes, etc.

[0005] Existing methods for dyeing silk fibers each have their own shortcomings. While acid dyes offer vibrant colors, a comprehensive color spectrum, and high dye uptake, they bind to silk fibers through ionic bonds, making them susceptible to solvation by water and typically exhibiting poor wet fastness. Metal complex dyes, which form complexes on fibers with the help of metal (chromium, cobalt) ions, exhibit good wet fastness. However, the presence of large amounts of metal ions in the fibers and dye liquor can negatively impact human health and the environment. Reactive dyes contain reactive groups in their structure and are the only type of reactive dye that can covalently bond with silk fibers. The bond energy of their covalent bonds is much greater than that of hydrogen bonds and van der Waals forces. During dyeing, they can react with the amino groups at the ends of the silk fiber macromolecule chains and the phenolic hydroxyl groups in the tyrosine residues to form covalent bonds and dye on the fibers. However, the covalent bonds formed between reactive dyes and protein fibers are mostly ester and amide groups, which are easily hydrolyzed and broken in strong acid and alkaline media. Therefore, reactive dyes cannot completely solve the problem of wet treatment fastness of silk fibers. In addition, there is a serious hydrolysis problem during the fixation process of reactive dyes, which produces a large amount of colored wastewater and is difficult to treat. Therefore, designing a dye that can form a strong covalent bond with silk fibers, giving them excellent wet treatment fastness and reducing the amount of wastewater discharged is an urgent problem that needs to be solved in the dyeing and finishing industry.

[0006] As the textile dyeing and finishing industry consumes the most water, water pollution has become a serious issue hindering its development. Dyeing wastewater contains large amounts of salt and chemical additives, which are difficult to degrade naturally, further eroding soil and water quality. Silk dyeing, in particular, requires the addition of large amounts of dye accelerators during the dyeing process. These accelerators pollute the water environment, increasing the difficulty of wastewater discharge and treatment. Summary of the Invention

[0007] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a salt-free, alkali-free and post-treatment-free method for dyeing silk with high fastness, which fills the technical gap in the salt-free and alkali-free silk dyeing industry, greatly saves the amount of dyes and auxiliaries used, and reduces the discharge of sewage.

[0008] The technical solution adopted by the present invention is:

[0009] The salt-free, alkali-free and post-treatment-free high-fastness silk dyeing method comprises the following steps:

[0010] (1) dissolving a penetrant and a moisturizer in a certain amount of water to obtain a first solution;

[0011] (2) adding the reactive dye to the first solution and stirring until fully dissolved to obtain a dye solution;

[0012] (3) Adding the prepared dye solution into the dye trough of the single yarn dyeing device composed of a dye trough and an extrusion device, then, while winding the silk yarn, the silk yarn passes through the dye trough filled with the dye solution, and the silk yarn adsorbed with the dye solution passes through the extrusion device, so that the dye solution penetrates into the yarn, and at the same time, the yarn is wound into a loose dyeing bobbin, and finally the dyeing is completed;

[0013] (4) After dyeing, the loose silk yarn is placed in a high-temperature and high-pressure steamer to perform a yarn-fixing reaction to complete the final dyeing.

[0014] The penetrant in step (1) is WA-M.

[0015] The moisturizing agent in the step (1) is a special surfactant L-635.

[0016] In the step (1), the amount of penetrant added is 1.0%-3.0% of the total weight of the first solution, the amount of moisturizer added is 1.0%-5.0% of the total weight of the first solution, the weight of water is 98.0%-92.0% of the total weight of the first solution, and the temperature of the water in the step (1) is 50-70°C.

[0017] The reactive dye in step (2) is a fluorine-containing multi-reactive group reactive dye; the amount of the reactive dye added is 1.0%-6.0% of the total weight of the first solution. The fluorine-containing multi-reactive group reactive dye is preferably Huntsman Acycloda SE series.

[0018] The single yarn coloring device in step (3) is a dyeing unit installed on the winding equipment. The dyeing unit consists of a dye trough and a yarn extrusion device. The single yarn passes through the dye trough, dye solution and extrusion device in sequence and is wound into a loose bobbin yarn.

[0019] The speed of the single yarn dyeing device in step (3) is 300-900 m / min, and the liquid-carrying rate of the liquid-carrying yarn is 40-90%.

[0020] The forming density of the loose bobbin yarn in step (3) is 0.30-0.4 g / cm 3 .

[0021] The silk yarn in step (3) is degummed yarn, and the silk is one or more of mulberry silk, tussah silk, castor silk (cassava silk), and spun silk.

[0022] The silk yarn in step (4) is steamed at a temperature of 100-110° C. for 30-60 minutes.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The present invention eliminates the addition of dye accelerators during the dyeing process, simplifies the process, is simple to operate, and uses no alkali agent, thereby improving the dye utilization rate and reducing damage to the fiber; improving the dye uptake and fixation rate, and achieving the effect of dyeing silk in a dark color with good color fastness.

[0025] (2) The present invention fills the technical gap in the silk dyeing industry without salt or alkali. It uses a fluorine-containing multi-active base reactive dye to dye silk, which can achieve salt-free and alkali-free dyeing of silk with high color fastness, reducing wastewater discharge and wastewater treatment difficulty.

[0026] (3) The present invention saves the amount of dyes and additives used, and thus saves energy and reduces emissions.

[0027] (4) The present invention can achieve high color fastness without post-processing.

[0028] (5) The dyeing process of the present invention is short and the coloring is fast, the processing efficiency is high, and it is suitable for small-batch, fast-paced production modes. DETAILED DESCRIPTION

[0029] The present invention is further described below with reference to the following examples, but they do not limit the implementation of the present invention.

[0030] Manufacturer:

[0031]

[0032] Test method:

[0033] K / S: Passed DATACOLOR computer color matching test;

[0034] Dry friction: passed the test of GB / T3920-2008 "Textiles - Tests for colour fastness - Colour fastness to friction";

[0035] Wet friction: passed the test of GB / T3920-2008 "Textiles - Tests for colour fastness - Colour fastness to friction";

[0036] Soap washing: passed ISO105C06:2010(E)-C2S test.

[0037] Example 1

[0038] The salt-free, alkali-free and post-treatment-free mulberry silk yarn dyeing method comprises the following steps:

[0039] (1) Preparation of dye solution: dissolve and mix penetrant WA-M: 1% (relative to the total weight of the solution), moisturizer L-635: 1% (relative to the total weight of the solution), water: 98% (relative to the total weight of the solution), and reactive dye red: 1% (relative to the total weight of the solution);

[0040] (2) The prepared dye solution is added into the dye trough of the single yarn coloring device with a dye trough and an extrusion device, and then the 22D degummed mulberry silk yarn is loosely wound at a speed of 700m / min. The mulberry silk yarn passes through the dye trough filled with dye solution at high speed. During the process of the yarn passing through the dye trough, the dye solution can quickly adhere to the yarn. The yarn adsorbed with the dye solution passes through the extrusion device again, which prompts the dye solution to quickly penetrate into the yarn and control the yarn liquid carrying rate at 50%. The yarn is dyed while winding. The forming density of the mulberry silk yarn is 0.32g / cm 3 ;

[0041] (3) The dyed loose silk yarn is placed in a high-temperature and high-pressure steamer for steaming. The steaming temperature is 100°C and the steaming time is 40 minutes. The coloring is completed.

[0042] Example 2

[0043] The salt-free, alkali-free and post-treatment-free mulberry silk yarn dyeing method comprises the following steps:

[0044] (1) Dye solution preparation: dissolve and mix penetrant WA-M: 1% (relative to the total weight of the solution), moisturizer L-635: 1% (relative to the total weight of the solution), water: 98% (relative to the total weight of the solution), and reactive dye blue: 1% (relative to the total weight of the solution);

[0045] (2) The prepared dye solution is added into the dye trough of the single yarn coloring device with a dye trough and an extrusion device, and then the 22D degummed mulberry silk yarn is loosely wound at a speed of 800m / min. The mulberry silk yarn passes through the dye trough filled with dye solution at high speed. During the process of the yarn passing through the dye trough, the dye solution can quickly adhere to the yarn. The yarn adsorbed with the dye solution passes through the extrusion device again, which prompts the dye solution to quickly penetrate into the yarn and control the yarn liquid carrying rate at 50%. The yarn dyeing is completed while winding. The forming density of the mulberry silk yarn is 0.35g / cm 3 ;

[0046] (3) The dyed loose silk bobbin yarn is placed in a high-temperature and high-pressure steamer for steaming at a temperature of 100°C for 60 minutes, and the coloring is completed.

[0047] Example 3

[0048] The salt-free, alkali-free and post-treatment-free mulberry silk yarn dyeing method comprises the following steps:

[0049] (1) Dye solution preparation: dissolve and mix penetrant WA-M: 1% (relative to the total weight of the solution), moisturizer L-635: 1% (relative to the total weight of the solution), water: 98% (relative to the total weight of the solution), and reactive dye brown: 1% (relative to the total weight of the solution);

[0050] (2) The prepared dye solution is added into the dye trough of the single yarn coloring device with a dye trough and an extrusion device, and then the 22D degummed mulberry silk yarn is loosely wound at a speed of 500m / min. The mulberry silk yarn passes through the dye trough filled with dye solution at high speed. During the process of the yarn passing through the dye trough, the dye solution can quickly adhere to the yarn. The yarn adsorbed with the dye solution passes through the extrusion device again, which prompts the dye solution to quickly penetrate into the yarn and control the yarn liquid carrying rate to about 50%. The yarn is dyed while winding. The forming density of the mulberry silk yarn is 0.30g / cm 3 ;

[0051] (3) The dyed loose silk yarn is placed in a high-temperature and high-pressure steamer for steaming. The steaming temperature is 100°C and the steaming time is 60 minutes. The coloring is completed.

[0052] The dyeing test results of Examples 1-3 are shown in Table 1:

[0053] Table 1 Dyeing test results of Examples 1-3

[0054] Test content Example 1 Example 2 Example 3 K / S 10.89 11.01 10.99 dry friction Level 4-5 Level 4-5 Level 4-5 Wet friction Level 4 Level 4-5 Level 4 Soaping Level 4-5 Level 4-5 Level 4-5

[0055] Thus, it can be seen that the dyeing process provided in this embodiment eliminates the dyeing accelerator in the dyeing process and reduces the damage of the alkali agent to the fiber without the need to add alkali, does not require post-processing, reduces energy consumption, greatly saves costs, and improves the dyeing effect of mulberry silk.

[0056] Example 4

[0057] The salt-free, alkali-free and post-treatment-free tussah silk yarn dyeing method comprises the following steps:

[0058] (1) Preparation of dye solution: dissolve and mix penetrant WA-M: 3% (relative to the total weight of the solution), moisturizer L-635: 5% (relative to the total weight of the solution), water: 92% (relative to the total weight of the solution), and reactive dye red: 6% (relative to the total weight of the solution);

[0059] (2) The prepared dye solution is added into the dye trough of the single yarn coloring device with a dye trough and an extrusion device, and then the 22D degummed tussah silk yarn is loosely wound at a speed of 700m / min. The tussah silk yarn passes through the dye trough filled with dye solution at high speed. During the process of the yarn passing through the dye trough, the dye solution can quickly adhere to the yarn. The yarn adsorbed with the dye solution passes through the extrusion device again, which prompts the dye solution to quickly penetrate into the yarn and control the yarn liquid carrying rate to about 90%. The yarn dyeing is completed while winding. The forming density of the tussah silk bobbin yarn is 0.32g / cm 3 ;

[0060] (3) The dyed loose tussah silk yarn is placed in a high-temperature and high-pressure steamer for steaming. The steaming temperature is 110°C and the steaming time is 40 minutes. The coloring is completed.

[0061] Example 5

[0062] The salt-free, alkali-free and post-treatment-free tussah silk yarn dyeing method comprises the following steps:

[0063] (1) Preparation of dye solution: dissolve and mix penetrant WA-M: 3% (relative to the total weight of the solution), moisturizer L-635: 5% (relative to the total weight of the solution), water: 92% (relative to the total weight of the solution), and reactive dye blue: 6% (relative to the total weight of the solution);

[0064] (2) The prepared dye solution is added into the dye trough of the single yarn coloring device with a dye trough and an extrusion device, and then the 22D degummed tussah silk yarn is loosely wound at a speed of 800m / min. The tussah silk yarn passes through the dye trough filled with dye solution at high speed. During the process of the yarn passing through the dye trough, the dye solution can quickly adhere to the yarn. The yarn adsorbed with the dye solution passes through the extrusion device again, which prompts the dye solution to quickly penetrate into the yarn and control the yarn liquid carrying rate to about 90%. The yarn dyeing is completed while winding. The forming density of the tussah silk bobbin yarn is 0.35g / cm 3 ;

[0065] (3) The dyed loose tussah silk yarn is placed in a high-temperature and high-pressure steamer for steaming. The steaming temperature is 110°C and the steaming time is 60 minutes. The coloring is completed.

[0066] Example 6

[0067] The salt-free, alkali-free and post-treatment-free tussah silk yarn dyeing method comprises the following steps:

[0068] (1) Dye solution preparation: dissolve and mix penetrant WA-M: 3% (relative to the total weight of the solution), moisturizer L-635: 5% (relative to the total weight of the solution), water: 92% (relative to the total weight of the solution), and reactive dye black: 6% (relative to the total weight of the solution);

[0069] (2) The prepared dye solution is added into the dye trough of the single yarn coloring device with a dye trough and an extrusion device, and then the 22D degummed tussah silk yarn is loosely wound at a speed of 600m / min. The tussah silk yarn passes through the dye trough filled with dye solution at high speed. During the process of the yarn passing through the dye trough, the dye solution can quickly adhere to the yarn. The yarn adsorbed with the dye solution passes through the extrusion device again, which prompts the dye solution to quickly penetrate into the yarn and control the yarn liquid carrying rate to about 90%. The yarn dyeing is completed while winding. The forming density of the tussah silk bobbin yarn is 0.30g / cm 3 ;

[0070] (3) The dyed loose tussah silk yarn is placed in a high-temperature and high-pressure steamer for steaming. The steaming temperature is 110°C and the steaming time is 60 minutes. The coloring is completed.

[0071] The dyeing test results of Examples 4-6 are shown in Table 2:

[0072] Table 2 Dyeing test results of Examples 4-6

[0073] Test content Example 4 Example 5 Example 6 K / S 24.78 24.89 24.99 dry friction Level 4 Level 4 Level 4 Wet friction Level 4 Level 4 Level 4 Soaping Level 4 Level 4 Level 3 / 4

[0074] Comparative Example 1:

[0075] The dyeing of mulberry silk yarn includes the following steps:

[0076] The data is converted based on dyeing 1 kg of mulberry silk.

[0077] 1. Pretreatment: With a bath ratio of 1:25, add 25L of water, 120g of degumming agent NKJL-50, 100g of soda ash, and 50g of refining agent into the dyeing machine to form a treatment solution. Place the mulberry silk into the treatment solution, heat it to 98°C, soak it for 30 minutes, then wash it with 75°C hot water until the washing solution is neutral, and spin dry.

[0078] 2. Dyeing: The bath ratio is 1:25. Add 25L of water, 50g of leveling agent L450, 10g of reactive yellow Y3RF to the dyeing machine. Dissolve the dye in 80℃ water in advance. Add 1000g of sodium sulfate and stir until it is completely dissolved. Soak the mulberry silk in warm water. Heat the dye bath to 40℃, add the mulberry silk, and heat it to 85℃ at 2℃ / min. Maintain the dye bath temperature at 88℃ and dye for 30 minutes. Then add 94g of soda ash and maintain the dye bath temperature at 85℃ for 60 minutes.

[0079] 3. Soap boiling: add 20L of clean water with a bath ratio of 1:20, add 20g of soaping agent WO, heat to 90℃, boil for 30 minutes, and wash with cold water until the washing liquid is clear;

[0080] 4. Fixation: add 20 L of clean water at a bath ratio of 1:20, add 50 g of fixing agent LT, raise the temperature to 85°C, fix the color for 50 minutes, drain the fixing solution, and dry the yarn to obtain the dyed mulberry silk yarn.

[0081] Comparative Example 2:

[0082] The dyeing of mulberry silk yarn includes the following steps:

[0083] The data is converted based on dyeing 1 kg of mulberry silk.

[0084] 1. Pretreatment: With a bath ratio of 1:25, add 25L of water, 120g of degumming agent NKJL-50, 100g of soda ash, and 50g of refining agent into the dyeing machine to form a treatment solution. Place the mulberry silk into the treatment solution, heat it to 98°C, soak it for 30 minutes, then wash it with 80°C hot water until the washing solution is neutral, and spin dry.

[0085] 2. Dyeing: The bath ratio is 1:25. Add 25L of water, 50g of leveling agent L450 and 60g of reactive blue BBRF to the dyeing machine. Dissolve the dye in 80℃ water in advance. Add 1750g of sodium sulfate and stir until it is completely dissolved. Soak the mulberry silk in warm water. Heat the dye bath to 40℃, add the mulberry silk, and heat it to 85℃ at 2℃ / min. Maintain the dye bath temperature at 90℃ and dye for 30 minutes. Then add 156g of soda ash and maintain the dye bath temperature at 85℃ for 60 minutes.

[0086] 3. Soap boiling, bath ratio is 1:20, add 20L of clean water, add 20g of soaping agent WO, heat to 90℃, boil for 30 minutes, wash with cold water until the washing liquid is clear;

[0087] 4. Color fixing: add 20L of clean water with a bath ratio of 1:20, add 50g of color fixing agent LT, raise the temperature to 85℃, fix the color for 50 minutes, drain the color fixing liquid, and dry the yarn to obtain the dyed mulberry silk yarn.

[0088] The dyeing test results of Comparative Example 1-2 are shown in Table 3:

[0089] Table 3 Dyeing test results of Comparative Examples 1-2

[0090] Test content Comparative Example 1 Comparative Example 2 K / S 11.03 25.06 dry friction Level 4 Level 4 Wet friction Level 4 Level 3 / 4 Soaping Level 4 Level 3 / 4

[0091] It can be seen that the test results of the comparative example and the present invention are not much different. In addition, the presence of salt and alkali in the comparative example causes partial hydrolysis of the dye, resulting in very poor wet rubbing and soaping fastness. The dyeing process provided by the present invention eliminates the dye accelerator in the dyeing process and does not require the addition of alkali. It also reduces the damage of the alkali agent to the fiber, eliminates the need for post-treatment, reduces energy consumption, greatly saves costs, and improves the dyeing effect of mulberry silk.

[0092] In summary, the embodiment of the present invention combines the use of a fluorine-containing multi-reactive group reactive dye to achieve salt-free, alkali-free, and post-processing-free dyeing while winding the yarn. The embodiment of the present invention dyes under salt-free and alkali-free conditions, reduces the hydrolysis of the reactive dye, achieves a dyeing and fixation rate of more than 99% for the reactive dye, solves the problem of poor fastness of silk fabrics to dark dyeing, and reduces fiber damage. The embodiment of the present invention is salt-free and alkali-free during the dyeing process, which reduces the difficulty of wastewater treatment and reduces dyeing costs. After dyeing, the embodiment of the present invention does not require any post-processing such as soaping, washing, and color fixation, which greatly reduces energy consumption. While reducing costs, the dyeing effect is also greatly improved.

Claims

1. A method for dyeing silk with high fastness without salt, alkali or post-treatment, characterized in that: The following steps are involved: (1) dissolving a penetrant and a moisturizer in a certain amount of water to obtain a first solution; (2) adding the reactive dye to the first solution and stirring until fully dissolved to obtain a dye solution; (3) Add the prepared dye solution into the dye trough of the single yarn dyeing device which is composed of a dye trough and an extrusion device. Then, the silk yarn passes through the dye trough filled with the dye solution while winding the silk yarn. The silk yarn adsorbed with the dye solution passes through the extrusion device, so that the dye solution penetrates into the yarn and is wound into a loose dyeing cone yarn at the same time, and finally the dyeing is completed; (4) After dyeing, the loose silk yarn is placed in a high-temperature and high-pressure steamer for a yarn-fixing reaction to complete the final dyeing; In step (1), the amount of penetrant added is 1.0%-3.0% of the total weight of the first solution, the amount of moisturizer added is 1.0%-5.0% of the total weight of the first solution, the weight of water is 98.0%-92.0% of the total weight of the first solution, and the temperature of the water in step (1) is 50-70°C; The reactive dye in step (2) is a fluorine-containing multi-reactive group reactive dye; the amount of the reactive dye added is 1.0%-6.0% of the total weight of the first solution; The single yarn coloring device in step (3) is a dyeing unit installed on the winding equipment. The dyeing unit consists of a dye trough and a yarn extrusion device. The single yarn passes through the dye trough and the extrusion device in sequence and is wound into a loose bobbin yarn.

2. The salt-free, alkali-free, and post-treatment-free method for dyeing silk with high fastness according to claim 1, characterized in that: The penetrant in step (1) is WA-M.

3. The salt-free, alkali-free, and post-treatment-free method for dyeing silk with high fastness according to claim 1, characterized in that: The moisturizing agent in step (1) is L-635.

4. The salt-free, alkali-free, and post-treatment-free method for dyeing silk with high fastness according to claim 1, wherein: The speed of the single yarn dyeing device in step (3) is 300-900 m / min, and the liquid-carrying rate of the liquid-carrying yarn is 40-90%.

5. The salt-free, alkali-free, and post-treatment-free method for dyeing silk with high fastness according to claim 1, wherein: The forming density of the loose bobbin yarn in step (3) is 0.30-0.4 g / cm 3 .

6. The salt-free, alkali-free, and post-treatment-free method for dyeing silk with high fastness according to claim 1, characterized in that: The silk yarn in step (3) is degummed yarn, and the silk is one or more of mulberry silk, tussah silk, castor silk, cassava silk, and spun silk.

7. The salt-free, alkali-free, and post-treatment-free method for dyeing silk with high fastness according to claim 1, characterized in that: The silk yarn in step (4) is steamed at a temperature of 100-110° C. for 30-60 minutes.

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