Dyeing method of mulberry silk

Abstract

The invention relates to the technical field of mulberry silk dyeing, and discloses a mulberry silk dyeing method which comprises the following steps: S1, pretreatment: immersing a mulberry silk raw material into an aqueous solution containing 0.5-1.5% of sodium carbonate, stirring for 20-40 minutes at the speed of 50-100 revolutions per minute at the temperature of 40-60 DEG C, taking out, and rinsing with deionized water until the mulberry silk raw material is neutral; the pretreated mulberry silk is put into a dyeing bath, the dyeing bath comprises 2-5% of reactive dye and 1-3 g / L of leveling agent, the bath ratio is controlled to be 1: 10-1: 20, the temperature is increased to 60-80 DEG C at the speed of 1-2 DEG C / min, and heat preservation dyeing is conducted for 30-60 min. In the pretreatment step, sodium carbonate concentration, temperature and stirring rate are controlled, so that the problem of poor dyeing uniformity caused by residual impurities on the fiber surface and non-uniform dyeing temperature control in the existing mulberry silk dyeing is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of mulberry silk dyeing, and particularly relates to a method for dyeing mulberry silk. Background Art

[0002] Mulberry silk is a natural animal protein fiber spun by silkworms, mainly produced in major sericulture countries such as China and India. Its fibers are slender and soft, with a unique irregular triangular cross-section. This structure gives it excellent gloss, good hygroscopicity and air permeability. At the same time, an insulating layer is formed by the air retained between the fibers, which can play a heat preservation role.

[0003] Most of the existing mulberry silk dyeing processes use low-concentration alkali liquor and low-temperature treatment of the fibers, resulting in residues of impurities such as wax and sericin on the surface of the mulberry silk and easy fiber entanglement. At the same time, the temperature control accuracy during dyeing is insufficient, causing uneven adsorption of dyes on the fiber surface and differences in internal diffusion rates, thus resulting in poor dyeing uniformity. Summary of the Invention

[0004] In order to make up for the above deficiencies, the present invention provides a method for dyeing mulberry silk, aiming to improve the problem of poor dyeing uniformity in the existing mulberry silk dyeing process.

[0005] To achieve the above object, the present invention provides the following technical solution: A method for dyeing mulberry silk includes the following steps:

[0006] S1. Pretreatment: Immerse the mulberry silk raw material in an aqueous solution containing 0.5 - 1.5% sodium carbonate, stir at a rate of 50 - 100 revolutions per minute at 40 - 60 °C for 20 - 40 minutes, take it out and rinse it with deionized water until neutral.

[0007] S2. Dyeing: Put the pretreated mulberry silk into the dyeing bath. The dyeing bath contains 2 - 5% reactive dye and 1 - 3 g / L leveling agent, and the bath ratio is controlled at 1:10 - 1:20. Heat it up to 60 - 80 °C at a rate of 1 - 2 °C per minute, keep it warm for dyeing for 30 - 60 minutes, and maintain the pH value at 4.5 - 5.5 by adding acid / alkali reagents during this period.

[0008] S3. Fixing: Add 8 - 12 g / L sodium sulfate and 3 - 5 g / L soda ash to the dyeing bath, heat it up to 85 - 95 °C, and keep it warm for fixing for 20 - 30 minutes.

[0009] S4. Cleaning: Wash the dyed mulberry silk with warm water at 40 - 50 °C for 2 - 3 times in sequence, then rinse it with cold water until the washing liquid is colorless, and finally dehydrate it at 800 - 1200 revolutions per minute and dry it.

[0010] By adopting the above technical solution, the impurities on the fiber surface are removed through the pre-treatment step by controlling the sodium carbonate concentration, temperature, and stirring rate, providing a uniform adhesion interface. By using a bath ratio of 1:10 - 1:20, a low heating rate of 1 - 2 °C / minute, a leveling agent, and pH adjustment in the dyeing step, dye aggregation and fiber damage are avoided, promoting uniform diffusion of the dye, achieving uniform adsorption and diffusion of the dye on the mulberry silk fiber, reducing color difference, and thus solving the problem of poor dyeing uniformity in the existing mulberry silk dyeing due to residual impurities on the fiber surface and uneven control of the dyeing temperature.

[0011] Preferably, in S1, the sodium carbonate concentration is 1%, the treatment temperature is 50 °C, the treatment time is 30 minutes, the stirring device is a vertical stirring kettle with temperature control function, and anti-winding guide plates are provided on the inner wall of the kettle.

[0012] Preferably, in S2, the reactive dye is a bis-reactive vinyl sulfone type dye, the dye concentration is 3%, the leveling agent is a fatty alcohol polyoxyethylene ether compound, and the dosage is 2 g / L.

[0013] Preferably, in S2, the bath ratio is 1:15, the heating rate is 1.5 °C / minute, the holding temperature is 70 °C, the holding time is 45 minutes, and the pH value is adjusted to 5.0.

[0014] Preferably, in S2, the dosage of sodium sulfate is 10 g / L, the dosage of soda ash is 4 g / L, the fixation temperature is 90 °C, and the fixation time is 25 minutes.

[0015] Preferably, in S2, the warm water washing temperature is 45 °C, the cold water rinsing time is 5 - 10 minutes, the drying temperature is 50 - 60 °C, and the drying time is 30 - 40 minutes.

[0016] Preferably, the dyeing bath in S2 further contains 0.1 - 0.3% penetrant JFC, and the addition time is when the temperature is raised to 30 °C.

[0017] Preferably, the bottom of the vertical stirring kettle is equipped with an ultrasonic oscillation device, and the oscillation frequency is 20 - 40 kHz.

[0018] Preferably, in S4, the drying equipment is a horizontal drying oven with air circulation, and the drying is carried out until the moisture content ≤ 8%.

[0019] Preferably, the reactive groups of the bis-reactive vinyl sulfone type dye are vinyl sulfone group and β-hydroxyethylsulfone sulfate group.

[0020] The present invention has the following beneficial effects:

[0021] 1. In the present invention, through the pre-treatment step by controlling the sodium carbonate concentration, temperature, and stirring rate, impurities on the fiber surface are removed to provide a uniform attachment interface. In the dyeing step, with a bath ratio of 1:10 - 1:20, a low heating rate of 1 - 2 °C per minute, a leveling agent, and pH adjustment, dye aggregation and fiber damage are avoided, promoting uniform diffusion of the dye, achieving uniform adsorption and diffusion of the dye on mulberry silk fibers, reducing color difference, and thus solving the problem of poor dyeing uniformity in the existing mulberry silk dyeing due to residual impurities on the fiber surface and uneven control of the dyeing temperature.

[0022] 2. In the present invention, a double-reactive group vinyl sulfone type dye containing vinyl sulfone group and β-hydroxyethyl sulfone sulfate group is used to form double covalent bonds with the amino and hydroxyl groups of mulberry silk protein. In the fixation stage, 8 - 12 g / L of sodium sulfate and 3 - 5 g / L of soda ash are added, and the temperature is raised to 85 - 95 °C and held for 20 - 30 minutes to promote the covalent bond formation between the dye reactive groups and the fiber, strengthening the fixation effect, thereby improving the dye fixation efficiency and significantly enhancing the soaping color fastness of the dyed product.

[0023] 3. In the present invention, an ultrasonic oscillation device is used to accelerate the stripping of impurities, shortening the pre-treatment time to 20 - 40 minutes. The penetrant JFC is used to enhance the permeability of the dye liquor, shortening the dyeing time to 30 - 60 minutes, thereby improving production efficiency. A horizontal drying oven with air circulation is used to dry at 50 - 60 °C for 30 - 40 minutes, avoiding fiber yellowing or embrittlement caused by high temperature. At the same time, through the design of an anti-tangling deflector plate, mechanical damage is reduced, and the moisture content is controlled at ≤8%, ensuring the soft hand feeling of the fiber and storage stability. Thus, while improving the overall production efficiency and the qualified rate of the finished product, the stability of the fiber physical properties can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the steps of a dyeing method for mulberry silk proposed by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] Refer to the attached Figure 1 The embodiments of the present invention provide a dyeing method for mulberry silk, including the following steps:

[0027] S1. Pretreatment: Immerse the raw mulberry silk in an aqueous sodium carbonate solution containing 0.5 - 1.5%, stir at a rate of 50 - 100 revolutions per minute at 40 - 60 °C for 20 - 40 minutes, take it out and rinse with deionized water until neutral;

[0028] S2. Dyeing: Put the pretreated mulberry silk into the dyeing bath. The dyeing bath contains 2 - 5% reactive dye and 1 - 3 g / L leveling agent. The bath ratio is controlled at 1:10 - 1:20. Heat it up to 60 - 80 °C at a rate of 1 - 2 °C per minute and keep it at a constant temperature for dyeing for 30 - 60 minutes. During this period, maintain the pH value at 4.5 - 5.5 by adding acid / alkali reagents;

[0029] S3. Fixing: Add 8 - 12 g / L of sodium sulfate and 3 - 5 g / L of soda ash to the dyeing bath, heat it up to 85 - 95 °C, and keep it at a constant temperature for fixing for 20 - 30 minutes;

[0030] S4. Cleaning: Wash the dyed mulberry silk with warm water at 40 - 50 °C for 2 - 3 times in sequence, then rinse it with cold water until the washing liquid is colorless, and finally dehydrate it at 800 - 1200 revolutions per minute and dry it.

[0031] Specifically, S1. Pretreatment: Through the control of the concentration, temperature, stirring rate and time of the sodium carbonate aqueous solution, remove the wax, grease and impurities on the surface of the mulberry silk, improve the cleanliness of the fiber surface, and provide a uniform attachment interface for dyeing; S2. Dyeing: Through the control of the concentration of reactive dye, the dosage of leveling agent, bath ratio, heating rate, temperature, time and pH value, realize the uniform adsorption and diffusion of the dye on the fiber, avoid dye aggregation and fiber damage caused by sudden temperature change, and ensure the controllability of the dyeing process; S3. Fixing: Through the control of the concentration of sodium sulfate, soda ash, temperature and time, promote the covalent bond combination between the dye and the mulberry silk protein, strengthen the dye fixing effect, and improve the color fastness of the dyed product; S4. Cleaning: Through the control of the number of warm water washes, temperature, cold water rinsing time and dehydration and drying parameters, gradually remove the residual dye and chemical reagents in the dyeing bath, reduce the influence of floating color, and at the same time prevent the fiber from yellowing or embrittling through low-temperature drying, ensuring the quality stability of the finished product; Through the pretreatment step, through the control of sodium carbonate concentration, temperature and stirring rate, remove the impurities on the fiber surface and provide a uniform attachment interface. By using a bath ratio of 1:10 - 1:20, a low heating rate of 1 - 2 °C per minute, leveling agent and pH value adjustment in the dyeing step, avoid dye aggregation and fiber damage, promote the uniform diffusion of the dye, realize the uniform adsorption and diffusion of the dye on the mulberry silk fiber, reduce color difference, thus solving the problem of poor dyeing uniformity in the existing mulberry silk dyeing due to residual impurities on the fiber surface and uneven control of dyeing temperature.

[0032] In S1, the sodium carbonate concentration is 1%, the treatment temperature is 50 °C, the treatment time is 30 minutes, the stirring equipment is a vertical stirring kettle with temperature control function, and the inner wall of the kettle is provided with an anti-winding guide plate.

[0033] Specifically, impurities, oils, and natural gums on the surface of mulberry silk raw materials can be effectively removed by an aqueous sodium carbonate solution, making the surface of the mulberry silk cleaner and providing a good foundation for subsequent dyeing. When the concentration is 1%, it can not only ensure the effect of removing impurities but also avoid damaging the mulberry silk fiber due to too high a concentration, which may affect its physical properties and dyeing effect. A treatment temperature of 50°C helps to accelerate the chemical reaction between sodium carbonate and the impurities on the surface of the mulberry silk, improving the treatment efficiency. At the same time, this temperature is within a suitable range and will not cause problems such as deformation and embrittlement of the mulberry silk fiber due to too high a temperature, ensuring the structural integrity and quality stability of the mulberry silk fiber. A treatment time of 30 minutes is sufficient for sodium carbonate to fully react with the impurities and remove them. If the time is too short, the impurities will not be removed completely; if the time is too long, it may increase energy consumption and the risk of damage to the fiber. Through the temperature control function in a vertical stirring kettle with a temperature control function, the temperature during the treatment process can be precisely controlled to keep the temperature stable at 50°C, ensuring the consistency and stability of the treatment effect. Avoiding poor treatment effects caused by temperature fluctuations, such as fiber damage due to too high a temperature and ineffective removal of impurities due to too low a temperature. Through the vertical stirring structure, the mulberry silk raw materials can be fully stirred in the aqueous sodium carbonate solution to ensure that all parts can be evenly contacted with the solution, improving the uniformity of the treatment. The anti-tangling guide plate can guide the flow direction of the solution to form an orderly circulation of the solution, reducing the possibility of the mulberry silk raw materials tangling with each other. This helps to ensure that each mulberry silk can be fully treated, avoiding insufficient treatment in some areas due to tangling, and also facilitating the extraction operation of the mulberry silk after the treatment is completed.

[0034] In S2, the reactive dye is a bis-reactive vinyl sulfone type dye, the dye concentration is 3%, the leveling agent is a fatty alcohol polyoxyethylene ether compound, and the dosage is 2 g / L.

[0035] Specifically, the bis-reactive vinyl sulfone type dye has two reactive groups, which can form covalent bonds with amino groups, hydroxyl groups, etc. on the mulberry silk fiber, enhancing the binding force between the dye and the fiber, thereby improving the washing fastness, rubbing fastness, etc. of the dyed product. A dye concentration of 3% can not only make the mulberry silk reach the ideal dyeing depth and color brightness but also avoid problems such as dye waste, uneven dyeing, and increased subsequent cleaning difficulty due to too high a concentration, taking into account both the dyeing effect and the cost. The fatty alcohol polyoxyethylene ether compound as a leveling agent has good emulsifying, dispersing, and retarding effects. It can reduce the affinity of the dye for the fiber, making the dye slowly dye the fiber and avoiding uneven dyeing caused by the too fast adsorption of the dye on the fiber surface, thereby improving the uniformity and reproducibility of the dyeing. A leveling agent dosage of 2 g / L can ensure the leveling effect while not affecting the dye uptake rate due to too much dosage, ensuring the efficient and stable progress of the dyeing process.

[0036] In S2, the liquor ratio is 1:15, the heating rate is 1.5 °C per minute, the holding temperature is 70 °C, the holding time is 45 minutes, and the pH value is adjusted to 5.0.

[0037] Specifically, a liquor ratio of 1:15 can ensure that the dye liquor fully submerges the mulberry silk, enabling the dye to be evenly dispersed around the fiber, providing a good environment for the combination of the dye and the fiber. At the same time, it can avoid dye waste caused by too large a liquor ratio or uneven dyeing caused by too small a liquor ratio. The heating rate is 1.5 °C per minute. This heating rate is moderate, allowing the dye to gradually and evenly adsorb and diffuse into the interior of the mulberry silk fiber, avoiding problems such as uneven dyeing and color mottling caused by too rapid heating, which makes the dye quickly accumulate on the fiber surface; it also prevents low dyeing efficiency due to too slow heating. Through the holding temperature of 70 °C, the dye molecules can have sufficient activity and energy, accelerating their diffusion into the fiber interior, promoting the chemical reaction between the dye and the fiber, and ensuring the dyeing depth and color brightness. Through the holding time of 45 minutes, it can ensure that the dye and the fiber fully react and combine, making the dyeing effect more stable and lasting. If the time is too short, the reaction between the dye and the fiber is insufficient, and the dyeing fastness and color effect are not good; if the time is too long, it may damage the fiber. By adjusting the pH value to 5.0 and being in an acidic environment, it is conducive to the combination of the bis-reactive group vinyl sulfone type dye and the mulberry silk fiber. At this pH value, the chemical properties of the dye and the fiber are conducive to the formation of covalent bonds, improving the dyeing efficiency and quality.

[0038] In S2, the dosage of sodium sulfate is 10 g / L, the dosage of soda ash is 4 g / L, the fixing temperature is 90 °C, and the fixing time is 25 minutes.

[0039] Specifically, sodium sulfate can reduce the charge repulsion on the surface of the mulberry silk fiber, promote the adsorption of the negatively charged reactive dye to the fiber surface, increase the dye uptake rate, and improve the dyeing depth and color saturation. A dosage of 10 g / L can effectively improve the dye utilization rate without excessive cost increase; soda ash, as a fixing agent, can provide an alkaline environment, prompting the reactive groups in the reactive dye to form covalent bonds with the hydroxyl or amino groups on the mulberry silk fiber, fixing the dye on the fiber and enhancing the dyeing fastness. This dosage can ensure the full progress of the fixing reaction without damaging the fiber due to excessive alkalinity; through the fixing temperature of 90 °C, it can provide sufficient energy for the fixing reaction, accelerating the formation of covalent bonds between the dye and the fiber, making the fixing reaction proceed quickly and fully, and improving the fixing effect and the stability of dyeing; through the fixing time of 25 minutes, it can ensure the complete formation of covalent bonds between the dye and the fiber, guaranteeing the dyeing fastness. If the time is too short, the fixing reaction is insufficient; if the time is too long, it may cause fiber damage and color change.

[0040] In S2, the temperature for warm water washing is 45 °C, the time for cold water rinsing is 5 - 10 minutes, the drying temperature is 50 - 60 °C, and the drying time is 30 - 40 minutes.

[0041] Specifically, the unfixed dyes and chemical auxiliaries on the surface of mulberry silk can be effectively removed by warm water at 45°C, while avoiding fiber shrinkage or dye color change caused by excessive temperature, and ensuring the hand feeling and color stability of the fiber; the residual impurities can be further removed by cold water rinsing, reducing the residual amount of chemical substances on the fiber surface, and the low-temperature environment can reduce fiber damage and maintain the dimensional stability of the fabric; by drying at a temperature of 50-60°C, the moisture in the mulberry silk can be quickly evaporated, improving the drying efficiency, and at the same time avoiding fiber yellowing, embrittlement or the generation of aurora due to high temperature, ensuring that the finished product has a soft hand feeling and uniform color; by drying for 30-40 minutes, it can ensure that the mulberry silk is completely dry, avoiding mildew or color change caused by residual moisture, and at the same time preventing fiber damage caused by over-drying, and balancing the drying effect and fabric quality.

[0042] The dyeing bath of S2 also contains 0.1-0.3% penetrant JFC, and the addition time is when the temperature is raised to 30°C.

[0043] Specifically, penetrant JFC can reduce the surface tension of the dye liquor, enhance the wettability and permeability of the dye liquor to mulberry silk fibers, and promote the rapid and uniform diffusion of the dye liquor into the fiber interior, avoiding uneven dyeing caused by insufficient penetration of the dye liquor; by adding it during the temperature rise stage at 30°C, penetrant JFC can act on the fiber surface prior to the dye, opening the pore structure of the fiber, providing a channel for the subsequent adsorption and diffusion of dye molecules, and improving the dyeing uniformity and efficiency; by controlling the addition time and dosage, it can avoid excessive penetration of the dye or fiber damage caused by too high penetrant concentration or improper addition time, ensure the stability of the dyeing process, and improve the color consistency of the finished product.

[0044] An ultrasonic oscillation device is equipped at the bottom of the vertical stirring kettle, and the oscillation frequency is 20-40 kHz.

[0045] Specifically, the ultrasonic oscillation device can destroy the dye particle aggregates through the cavitation effect of ultrasonic waves, disperse them into smaller particle sizes, and uniformly distribute them in the dye liquor, avoiding uneven dyeing caused by dye precipitation or too high local concentration; the high-frequency oscillation promotes the high-frequency collision between the dye liquor molecules and the mulberry silk fibers, reduces the liquid film resistance on the fiber surface, accelerates the penetration of the dye liquor into the fiber interior, and at the same time increases the diffusion rate of dye molecules in the fiber pores, shortening the dyeing time; through the mechanical vibration effect of ultrasonic waves, the dye can be more evenly adsorbed on the fiber surface and penetrate into the interior, promoting the more sufficient covalent bond combination between the dye and the fiber, and improving the color uniformity and color fastness of the dyed finished product; the cavitation effect of ultrasonic waves can remove the dye deposits or chemical residues attached to the bottom of the kettle and the surface of the stirring device, reduce equipment scaling, maintain the operation efficiency of the stirring system, and reduce the cleaning frequency.

[0046] In S4, the drying equipment is a horizontal drying box with air circulation, and the drying is carried out until the moisture content ≤ 8%.

[0047] Specifically, the air-blowing circulation system makes the temperature field in the drying box evenly distributed by forcing air flow, accelerates the evaporation of moisture in the fabric, ensures that the moisture content of each part uniformly drops to ≤8%, and avoids mildew or color change caused by local moisture residue; controlling the moisture content within a safe range can prevent problems such as fiber swelling, inferior hand feeling, or dimensional instability of the fabric due to excessive moisture, and at the same time avoid fiber embrittlement and a decrease in breaking strength caused by over-drying; the low moisture content state can reduce the quality risks caused by moisture participating in chemical reactions during fabric storage or subsequent processing, ensuring process coherence and finished product stability; the horizontal structure combined with air-blowing circulation expands the contact area between the fabric and hot air, shortens the drying time, and at the same time avoids the problem of uneven drying between the upper and lower layers that may occur in traditional static drying, improving production efficiency and finished product consistency.

[0048] The reactive groups of the bis-reactive group vinyl sulfone type dye are vinyl sulfone group and β-hydroxyethyl sulfone sulfate group.

[0049] Specifically, the vinyl sulfone group directly undergoes a nucleophilic addition reaction with fiber hydroxyl / amino groups under alkaline conditions to achieve fixation; the β-hydroxyethyl sulfone sulfate group can generate vinyl sulfone group through hydrolysis under acidic to neutral conditions, gradually releasing its activity, avoiding excessive hydrolysis of the dye due to too strong alkalinity in the initial stage of dyeing, and improving the dye utilization rate; the dual reactive groups form double covalent bonds with the fiber, significantly enhancing the dye-fiber binding force and the color fastness to washing, rubbing, etc.; the characteristic of releasing activity step by step can reduce the uneven dyeing caused by too high instantaneous dyeing rate, especially suitable for the uniform dyeing of mulberry silk; the synergistic effect of the two groups allows the adoption of a step-by-step dyeing process of "first acidic adsorption and then alkaline fixation", taking into account both the dye uptake rate and the fixation efficiency, simplifying the process operation and reducing energy consumption; it is less sensitive to process parameters such as water quality hardness and temperature fluctuations, adapts to different production conditions, and improves dyeing stability.

[0050] The following is a further introduction in combination with specific embodiments:

[0051] Embodiment:

[0052] S1. Pretreatment: Immerse the mulberry silk raw material in an aqueous sodium carbonate solution containing 0.5 - 1.5%, stir at a rate of 50 - 100 revolutions per minute at 40 - 60°C for 20 - 40 minutes, and after taking it out, rinse it with deionized water until it is neutral.

[0053] S2. Dyeing: Put the pretreated mulberry silk into the dyeing bath. The dyeing bath contains 2 - 5% reactive dye and 1 - 3 g / L leveling agent, the bath ratio is controlled at 1:10 - 1:20, heat it up to 60 - 80°C at a rate of 1 - 2°C per minute, keep it warm and dye for 30 - 60 minutes, and maintain the pH value at 4.5 - 5.5 by adding acid / alkali reagents during this period.

[0054] S3. Fixation: Add 8 - 12 g / L of sodium sulfate and 3 - 5 g / L of sodium carbonate into the dyeing bath, heat up to 85 - 95 °C, and keep the temperature for 20 - 30 minutes for fixation.

[0055] S4. Cleaning: Wash the dyed mulberry silk with warm water at 40 - 50 °C for 2 - 3 times successively, then rinse with cold water until the washing liquid is colorless, and finally dehydrate at 800 - 1200 revolutions per minute and dry.

[0056] For the dyeing method of mulberry silk according to this embodiment of claim 1, in S1, the concentration of sodium carbonate is 1%, the treatment temperature is 50 °C, the treatment time is 30 minutes, the stirring device is a vertical stirring kettle with temperature control function, and an anti - entanglement guide plate is set on the inner wall of the kettle.

[0057] For the dyeing method of mulberry silk according to this embodiment of claim 1, in S2, the reactive dye is a double - reactive - group vinyl sulfone - type dye, the dye concentration is 3%, the leveling agent is a fatty alcohol polyoxyethylene ether - type compound, and the dosage is 2 g / L.

[0058] For the dyeing method of mulberry silk according to this embodiment of claim 1, in S2, the bath ratio is 1:15, the heating rate is 1.5 °C per minute, the holding temperature is 70 °C, the holding time is 45 minutes, and the pH value is adjusted to 5.0.

[0059] For the dyeing method of mulberry silk according to this embodiment of claim 1, in S2, the dosage of sodium sulfate is 10 g / L, the dosage of sodium carbonate is 4 g / L, the fixation temperature is 90 °C, and the fixation time is 25 minutes.

[0060] For the dyeing method of mulberry silk according to this embodiment of claim 1, in S2, the temperature of warm - water washing is 45 °C, the time of cold - water rinsing is 5 - 10 minutes, the drying temperature is 50 - 60 °C, and the drying time is 30 - 40 minutes.

[0061] For the dyeing method of mulberry silk according to this embodiment of claim 1, the dyeing bath in S2 further contains 0.1 - 0.3% penetrant JFC, and the addition time is when the temperature is raised to 30 °C.

[0062] For the dyeing method of mulberry silk according to this embodiment of claim 2, an ultrasonic oscillation device is equipped at the bottom of the vertical stirring kettle, and the oscillation frequency is 20 - 40 kHz.

[0063] For the dyeing method of mulberry silk according to this embodiment of claim 1, in S4, the drying equipment is a horizontal drying oven with air - blowing circulation, and it is dried until the moisture content ≤ 8%.

[0064] For the dyeing method of mulberry silk according to this embodiment of claim 3, the reactive groups of the double - reactive - group vinyl sulfone - type dye are vinyl sulfone group and β - hydroxyethylsulfone sulfate group.

[0065] Comparative Example 1:

[0066] S1 was treated with 0.5% sodium carbonate at 40 °C for 40 minutes, and stirred using a common open container (without a deflector);

[0067] The remaining steps were the same as those in Example 1.

[0068] Comparative Example 2:

[0069] The heating rate of S2 was 5 °C / minute, directly heated to 80 °C and held for 30 minutes, and no leveling agent was added;

[0070] The remaining steps were the same as those in Example 1.

[0071] Table 1:

[0072] Comparison Example Comparative Example 1 Fiber winding rate (%) 2 25 Inner layer fiber impurity residue rate (%) 1 22 Color difference after dyeing (ΔE) 0.1 1.8

[0073] Table 2:

[0074]

[0075]

[0076] It can be seen from Table 1 that the fiber winding rate, the residual rate of impurities on the inner layer fibers, and the color difference after dyeing of the examples are all better than those of Comparative Example 1. Therefore, it can be concluded that the pretreatment steps can remove impurities on the fiber surface and provide a uniform adhesion interface through a sodium carbonate concentration of 1%, a treatment temperature of 50 °C, and stirring rate control; it can be seen from Table 2 that through a bath ratio of 1:10 - 1:20, a low heating rate of 1 - 2 °C / minute, a leveling agent, and pH value adjustment, dye aggregation and fiber damage can be avoided, and uniform dye diffusion can be promoted.

[0077] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for dyeing mulberry silk, characterized in that, It includes the following steps: S1. Pretreatment: Immerse the raw mulberry silk in an aqueous solution containing 0.5 - 1.5% sodium carbonate, stir at a rate of 50 - 100 revolutions per minute at 40 - 60 °C for 20 - 40 minutes, take it out and rinse it with deionized water until neutral; S2. Dyeing: Put the pretreated mulberry silk into the dyeing bath. The dyeing bath contains 2 - 5% reactive dye and 1 - 3 g / L leveling agent, the bath ratio is controlled at 1:10 - 1:20, heat up to 60 - 80 °C at a rate of 1 - 2 °C per minute, keep the temperature for dyeing for 30 - 60 minutes, and maintain the pH value at 4.5 - 5.5 by adding acid / alkali reagents during this period; S3. Fixing: Add 8 - 12 g / L sodium sulfate and 3 - 5 g / L soda ash to the dyeing bath, heat up to 85 - 95 °C, keep the temperature for fixing for 20 - 30 minutes; S4. Cleaning: Wash the dyed mulberry silk with warm water at 40 - 50 °C for 2 - 3 times in sequence, then rinse it with cold water until the washing liquid is colorless, and finally dehydrate it at 800 - 1200 revolutions per minute and then dry it.

2. The dyeing method of mulberry silk according to claim 1, characterized in that: In S1, the concentration of sodium carbonate is 1%, the treatment temperature is 50 °C, the treatment time is 30 minutes, the stirring equipment is a vertical stirring kettle with temperature control function, and an anti-tangling deflector is arranged on the inner wall of the kettle.

3. A dyeing method for mulberry silk according to claim 1, characterized in that: In S2, the reactive dye is a bis-reactive group vinyl sulfone type dye, the dye concentration is 3%, the leveling agent is a fatty alcohol polyoxyethylene ether compound, and the dosage is 2 g / L.

4. A method for dyeing mulberry silk according to claim 1, characterized in that: In S2, the bath ratio is 1:15, the heating rate is 1.5 °C per minute, the holding temperature is 70 °C, the holding time is 45 minutes, and the pH value is adjusted to 5.

0.

5. A method for dyeing mulberry silk according to claim 1, characterized in that: In S2, the dosage of sodium sulfate is 10 g / L, the dosage of soda ash is 4 g / L, the fixing temperature is 90 °C, and the fixing time is 25 minutes.

6. A method for dyeing mulberry silk according to claim 1, characterized in that: In S2, the temperature of warm water washing is 45 °C, the time of cold water rinsing is 5 - 10 minutes, the drying temperature is 50 - 60 °C, and the drying time is 30 - 40 minutes.

7. A dyeing method for mulberry silk according to claim 1, characterized in that: The dyeing bath in S2 also contains 0.1 - 0.3% penetrant JFC, and the addition time is when the temperature is raised to 30 °C.

8. A dyeing method for mulberry silk according to claim 2, characterized in that: An ultrasonic oscillation device is equipped at the bottom of the vertical stirring kettle, and the oscillation frequency is 20 - 40 kHz.

9. A method for dyeing mulberry silk according to claim 1, characterized in that: In S4, the drying equipment is a horizontal drying oven with air circulation, and it is dried until the moisture content ≤ 8%.

10. A method for dyeing mulberry silk according to claim 3, characterized in that: The reactive groups of the bis-reactive group vinyl sulfone type dye are vinyl sulfone group and β-hydroxyethylsulfone sulfate group.

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