Dyeing process for improving dyeing saturation and color fastness and brocade-spandex dyed fabric

Abstract

The invention relates to the technical field of dyeing of brocade-spandex fabrics, and particularly discloses a dyeing process for improving dyeing saturation and color fastness and a brocade-spandex dyed fabric. A dyeing process for improving dyeing saturation and color fastness comprises the following steps: firstly, mixing dye, a leveling agent, brocade spandex gray cloth and water to prepare primarily dyed cloth; then adding a color fixing agent into the primarily dyed cloth to obtain color-fixed wet cloth; and finally, loosening, drying and shaping the color-fixed wet cloth to obtain the brocade-spandex dyed fabric. A brocade-spandex dyed fabric is prepared by a dyeing process for improving dyeing saturation and color fastness. According to the method, the problems of non-uniform dyeing and low color fastness of the brocade-spandex fabric are effectively solved, and the brocade-spandex dyed fabric with good dyeing saturation and color fastness is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of dyeing nylon-spandex fabrics, and in particular to a dyeing process for improving dyeing saturation and color fastness and a nylon-spandex dyed fabric. Background Art

[0002] Nylon-spandex fabric is a blend of nylon and spandex fibers, combining the advantages of both fibers: high strength, wear resistance, and dimensional stability, as well as excellent elastic recovery. Clothing made of nylon-spandex fabric not only fits the body curve, but also gives the wearer a sense of comfort without pressure. Therefore, it is widely used in yoga pants, sportswear, tights and other products.

[0003] In current technology, acid dyes are usually used to dye nylon-spandex fabrics. However, during the dyeing process, due to the large difference in dyeing properties between nylon and spandex, acid dyes are difficult to dye spandex, which easily leads to whitening of some spandex fibers, resulting in uneven dyeing and low dyeing saturation, making the fabric appear to be not full of color, old and lacking vitality, thus affecting the visual effect and wearing experience. However, if the amount of acid dyes used is increased to improve the problem of uneven dyeing and low dyeing saturation, although it is feasible to a certain extent, it will cause the fabric to absorb dye excessively, thus affecting color fastness.

[0004] In view of the above-mentioned related technologies, the inventors believe that it is necessary to improve the existing nylon fabric dyeing process to obtain nylon-ammonia dyed fabrics with good dyeing saturation and color fastness. Summary of the invention

[0005] In order to overcome the technical problem that it is difficult to simultaneously improve the dyeing saturation and color fastness of nylon-ammonia dyed fabrics in the prior art, the present application provides a dyeing process and nylon-ammonia dyed fabrics for improving dyeing saturation and color fastness. The present application effectively solves the problems of uneven dyeing and low color fastness of nylon-ammonia fabrics through specific dyeing steps and the coordinated use of a leveling agent, a pH regulator, and a color fixing agent, and obtains nylon-ammonia dyed fabrics with good dyeing saturation and color fastness.

[0006] A dyeing process for improving dyeing saturation and color fastness comprises the following steps: Step 1: Slowly add an appropriate amount of soft water to the dye, then add 40%-60% by weight of a leveling agent, fully dissolve and stir until mixed evenly to obtain a dye solution; Step 2: Pump a certain amount of soft water into the dye vat, and add nylon-spandex fabric and the remaining leveling agent under the drive of water flow, then pump the dye solution into the dye vat, and control the amount of water so that the bath ratio of nylon-spandex fabric is 1:(15-30), then heat it to 80-85℃ at a heating rate of 2-3℃ / min, and keep it warm for 10-20min; Step 3: Add pH regulator to the dye vat, then heat it to 100-105°C at a heating rate of 0.5-2°C / min, keep it warm for 30-35 minutes, then cool it to below 40°C at a cooling rate of 2-3°C / min, drain the water, and obtain the primary dyed fabric; Step 4: Continue to add appropriate amount of soft water to the dye vat so that the bath ratio of the primary dyed fabric is 1:(15-30), then add pH regulator, then heat up to 80-85°C at a heating rate of 3-4°C / min, then add color fixing agent to the dye vat, the adding time is controlled within 8-12min, keep warm for 25-30min, finally cool down to below 40°C at a cooling rate of 2.5-3°C / min, drain, and obtain color fixing wet cloth; Step 5: After the color-fixing wet cloth is loosened, dried and shaped, the nylon-ammonia dyed fabric is obtained; The leveling agent is a mixture of secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose, and its usage is 1%-3% of the mass of the nylon-spandex fabric.

[0007] In the above technical scheme, the present application enhances the binding force between spandex fiber and dye through specific dyeing process steps and the application of leveling agent, ensuring the uniform adsorption and firm fixation of dye on nylon-spandex fiber. By adopting a leveling agent mixed with secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose, these four ingredients act together on nylon-spandex fabric, so that the dye can be more evenly distributed on the fiber surface and more evenly penetrate into the fiber, enhancing the absorption capacity of nylon-spandex fiber, especially spandex, for dye, effectively improving the dyeing saturation and color fastness, and improving the color saturation and durability of nylon-spandex dyed fabrics.

[0008] Preferably, the mass ratio of the secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose is (30-40): (20-40): (20-30): (10-20).

[0009] In the above technical scheme, the present application further optimizes the formula of the leveling agent by limiting the mass ratio of secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose to (30-40): (20-40): (20-30): (10-20), so that its effect on the nylon-spandex cloth is more uniform and effective, and the dye is promoted to better penetrate into the fiber, thereby providing a more uniform dyeing effect during the dyeing process, while reducing the loss of the dye and further improving the color fastness.

[0010] Preferably, the mass ratio of the secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose is 35:25:25:15.

[0011] In the above technical scheme, the present application further improves the performance of the leveling agent by further optimizing the mass ratio of secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose, ensuring the uniform adsorption and fixation of the dye on the nylon-spandex fiber, thereby providing a more uniform dyeing effect during the dyeing process, while reducing the loss of the dye and further improving the color fastness.

[0012] Preferably, the pH adjuster in step 3 is acetic acid, and the pH adjuster adjusts the pH value to 4-5. In the above technical scheme, the present application optimizes the adsorption state of the dye molecules on the fiber surface by controlling the pH value to 4-5 by using acetic acid during the dyeing process, thereby improving the dyeing saturation and color fastness.

[0013] Preferably, the dye is a weak acid dye, and the amount of the weak acid dye used is 0.1%-5% of the mass of the nylon-spandex grey cloth.

[0014] In the above technical solution, the present application uses weak acid dyes, and the amount thereof is precisely controlled between 0.1% and 5% of the mass of the nylon-spandex fabric, thereby ensuring the affinity of the dyes with the fibers and avoiding the problem of decreased color fastness caused by excessive dyes. Weak acid dyes have better dyeing properties at lower pH values, which complements the step of adjusting the pH value to 4-5 in the present application, and together they work to improve dyeing saturation and color fastness.

[0015] Preferably, the color fixing agent is 3-chloro-2-hydroxypropyltrimethylammonium chloride, and its usage is 10%-20% of the mass of the nylon-spandex fabric.

[0016] In the above technical scheme, the present application further enhances the binding force between the dye and the fiber through the use of 3-chloro-2-hydroxypropyltrimethylammonium chloride. 3-chloro-2-hydroxypropyltrimethylammonium chloride can form stable chemical bonds with nylon-spandex fibers and increase the activity of acid dyes, thereby significantly improving the color fastness of the fabric.

[0017] Preferably, the pH adjuster in step 4 is DL-hydroxysuccinic acid, and the pH adjuster adjusts the pH value to 4-5.

[0018] In the above technical scheme, the present application further optimizes the adsorption state of the dye molecules on the fiber surface by adjusting the pH value to 4-5 using DL-hydroxysuccinic acid during the dyeing process, ensuring a stronger bond between the dye and the fiber, thereby further improving the dyeing saturation and color fastness.

[0019] In the second aspect, the present application provides a nylon-ammonia dyed fabric using the following technical solution: A nylon-ammonia dyed fabric is prepared by the dyeing process for improving dyeing saturation and color fastness as described in the first aspect.

[0020] In the above technical scheme, the present application obtains a nylon-ammonia dyed fabric with good comprehensive performance through the use of a specific dyeing process and materials. Such a fabric not only meets high standards in terms of color vividness and color fastness to washing, but also shows good performance in terms of wear resistance, wrinkle resistance and breathability. It is particularly suitable for making sportswear, outdoor equipment and daily casual clothing, etc., meeting consumers' demand for high-quality, high-performance clothing. At the same time, in the dyeing process of the present application, the leveling agent, pH regulator and fixing agent used are all environmentally friendly materials, which are friendly to the environment, meet the current textile industry's requirements for green production, and have broad market application prospects.

[0021] In summary, the present application includes at least one of the following beneficial technical effects: 1. In the present application, by using a leveling agent composed of a mixture of secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose, the dye can be more evenly distributed on the fiber surface and can more evenly penetrate into the fiber interior, thereby enhancing the adsorption of the dye to nylon-spandex, especially spandex, thereby effectively improving the dyeing saturation and color fastness, and improving the color saturation and durability of nylon-spandex dyed fabrics.

[0022] 2. This application further enhances the binding force between the dye and the fiber by selecting 3-chloro-2-hydroxypropyltrimethylammonium chloride as a color fixing agent and using it in combination with DL-hydroxysuccinic acid. 3-chloro-2-hydroxypropyltrimethylammonium chloride can form stable chemical bonds with nylon-spandex fibers and increase the activity of acid dyes, while DL-hydroxysuccinic acid can further promote this process, thereby significantly improving the color fastness of the fabric. DETAILED DESCRIPTION

[0023] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0024] Example 1 A dyeing process for improving dyeing saturation and color fastness comprises the following steps: Step 1: Slowly add an appropriate amount of soft water to 0.1 kg of dye, then add 0.05 kg of leveling agent, stir until fully dissolved and mixed to obtain dye solution.

[0025] Step 2: Add appropriate amount of soft water to 10kg nylon-spandex grey cloth, soak for 8 minutes, then add 0.05kg leveling agent, then pump the dye solution into the dye vat, and control the water volume so that the bath ratio of the nylon-spandex grey cloth is 1:15, then heat it to 80℃ at a heating rate of 2℃ / min and keep it warm for 10 minutes.

[0026] Step 3: Add acetic acid to the dye vat, adjust the pH value to 4, then heat up to 100°C at a heating rate of 0.5°C / min, keep warm for 30 minutes, then cool down to below 40°C at a cooling rate of 2°C / min, drain the water, and obtain the initially dyed fabric.

[0027] Step 4: Continue to add appropriate amount of soft water to the dye vat so that the bath ratio of the primary dyed fabric is 1:15, then add DL-hydroxysuccinic acid, adjust the pH value to 4, then heat up to 80°C at a heating rate of 3°C / min, then add 2kg of color fixing agent to the dye vat, control the addition time within 8min, keep warm for 25min, finally cool down to below 40°C at a cooling rate of 2.5°C / min, drain the water, and obtain a color-fixed wet cloth.

[0028] Step 5: After the color-fixing wet cloth is loosened, dried and shaped, the nylon-ammonia dyed fabric is obtained.

[0029] Among them, the nylon-spandex cloth is homemade.

[0030] The dye is a mixture of CI acid orange 67, CI acid red 336, CI acid red 127, and CI acid blue 260 in a mass ratio of 2:25:40.

[0031] The leveling agent is a mixture of secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose in a mass ratio of 30:40:20:10.

[0032] Among them, the secondary alcohol polyoxyethylene ether is secondary alcohol polyoxyethylene ether S-90 purchased from Guangzhou Taili Chemical Co., Ltd.

[0033] Among them, calcium lignin sulfonate was purchased from Guangzhou Taili Chemical Co., Ltd.

[0034] Among them, soapberry fruit extract was purchased from Shaanxi Lvlai Biotechnology Co., Ltd. with a specification of 10:1.

[0035] The hydroxypropyl cellulose is hydroxypropyl methylcellulose HPMC purchased from Guangzhou Taili Chemical Co., Ltd.

[0036] Wherein, the fixing agent is 3-chloro-2-hydroxypropyltrimethylammonium chloride.

[0037] Among them, 3-chloro-2-hydroxypropyltrimethylammonium chloride was purchased from Zhongshan Dixin Chemical Co., Ltd.

[0038] Among them, DL-hydroxysuccinic acid was purchased from Guangzhou Langxin Chemical Co., Ltd.

[0039] Example 2 A dyeing process for improving dyeing saturation and color fastness, which is different from Example 1, comprises the following steps: Step 1: Slowly add an appropriate amount of soft water to 0.1 kg of dye, then add 0.15 kg of leveling agent, stir until fully dissolved and mixed to obtain dye solution.

[0040] Step 2: Add appropriate amount of soft water to 10kg nylon-spandex grey cloth, soak for 12 minutes, then add 0.15kg leveling agent, then pump the dye solution into the dye vat, and control the water volume so that the bath ratio of the nylon-spandex grey cloth is 1:20, then heat it to 85℃ at a heating rate of 3℃ / min and keep it warm for 20 minutes.

[0041] Step 3: Add acetic acid to the dye vat, adjust the pH value to 5, then heat up to 105°C at a heating rate of 2°C / min, keep warm for 35 minutes, then cool down to below 40°C at a cooling rate of 3°C / min, drain the water, and obtain the initially dyed fabric.

[0042] Step 4: Continue to add appropriate amount of soft water to the dye vat so that the bath ratio of the primary dyed fabric is 1:20, then add DL-hydroxysuccinic acid, adjust the pH value to 5, then heat up to 80°C at a heating rate of 3°C / min, then add 1kg of color fixing agent to the dye vat, and control the addition time within 12min. After adding, keep warm for 30min, and finally cool down to below 40°C at a cooling rate of 3°C / min, drain the water, and obtain a color-fixed wet cloth.

[0043] Step 5: After the color-fixing wet cloth is loosened, dried and shaped, the nylon-ammonia dyed fabric is obtained.

[0044] The leveling agent is a mixture of secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose in a mass ratio of 30:20:30:20.

[0045] Example 3 A dyeing process for improving dyeing saturation and color fastness, which is different from Example 1, comprises the following steps: Step 1: Slowly add an appropriate amount of soft water to 0.1 kg of dye, then add 0.1 kg of leveling agent, stir until fully dissolved and mixed to obtain dye solution.

[0046] Step 2: Add appropriate amount of soft water to 10kg nylon-spandex grey cloth, soak for 10 minutes, then add 0.1kg leveling agent, then pump the dye solution into the dye vat, and control the water volume so that the bath ratio of the nylon-spandex grey cloth is 1:20, then heat it to 82℃ at a heating rate of 2.5℃ / min and keep it warm for 15 minutes.

[0047] Step 3: Add acetic acid to the dye vat, adjust the pH value to 4.5, then heat up to 103°C at a heating rate of 2°C / min, keep warm for 32 minutes, then cool down to below 40°C at a cooling rate of 2.5°C / min, drain the water, and obtain the primary dyed fabric.

[0048] Step 4: Continue to add appropriate amount of soft water to the dye vat so that the bath ratio of the primary dyed fabric is 1:20, then add DL-hydroxysuccinic acid, adjust the pH value to 4.5, then heat up to 83°C at a heating rate of 3.5°C / min, then add 1.5kg of color fixing agent to the dye vat, control the addition time within 10min, keep warm for 30min, finally cool down to below 40°C at a cooling rate of 3°C / min, drain, and obtain a color-fixed wet cloth.

[0049] Step 5: After the color-fixing wet cloth is loosened, dried and shaped, the nylon-ammonia dyed fabric is obtained.

[0050] The leveling agent is a mixture of secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose in a mass ratio of 35:25:25:15.

[0051] Example 4 A dyeing process for improving dyeing saturation and color fastness, wherein the difference from Example 1 is that the fixing agent in step 4 is BSF FIX of Archroma Chemicals (China) Co., Ltd.

[0052] Example 5 A dyeing process for improving dyeing saturation and color fastness, which is different from Example 1 in that the amount of dye used in step 1 is 0.2 kg.

[0053] Example 6 A dyeing process for improving dyeing saturation and color fastness, which is different from Example 1 in that the amount of dye used in step 1 is 0.3 kg.

[0054] Example 7 A dyeing process for improving dyeing saturation and color fastness, which is different from Example 1 in that the amount of dye used in step 1 is 0.4 kg.

[0055] Comparative Example 1 A dyeing process, which is different from Example 1 in that the secondary alcohol polyoxyethylene ether in the leveling agent is replaced by an equal amount of fatty alcohol polyoxyethylene ether AEO9.

[0056] Comparative Example 2 A dyeing process, which is different from Example 1 in that the calcium lignin sulfonate in the leveling agent is replaced by sodium dodecylbenzene sulfonate in an equal amount.

[0057] Comparative Example 3 A dyeing process, which is different from Example 1 in that the soapberry fruit extract in the leveling agent is replaced with Tween 80 in equal amounts.

[0058] Comparative Example 4 A dyeing process, which is different from Example 1 in that the hydroxypropyl cellulose in the leveling agent is replaced by polyethylene glycol monomethyl ether in an equal amount.

[0059] Comparative Example 5 A dyeing process, which is different from Example 1 in that the leveling agent is replaced by water in equal amount.

[0060] Performance test samples: nylon-spandex dyed fabrics prepared by the dyeing processes of Examples 1-7 and Comparative Examples 1-5, respectively, wherein the nylon-spandex grey fabrics used in the dyeing processes are the same.

[0061] Test items: 1. Determine the color fastness to washing in accordance with GB / T 3921-2008 Textiles - Tests for Color Fastness - Color Fastness to Washing with Soap.

[0062] 2. The color fastness to perspiration shall be determined in accordance with GB / T 3922-2013 “Textiles—Tests for Color Fastness—Colour Fastness to Perspiration”.

[0063] 3. Select 10 quality inspectors to conduct sensory evaluation on the dyeing uniformity and dyeing saturation of the nylon-ammonia dyed fabrics prepared by the dyeing process. The evaluation results are averaged. The evaluation criteria are as follows: Dyeing uniformity: 1 point: Indicates that the dyeing uniformity is extremely poor and some white spots are exposed on the fabric.

[0064] 2 points: Indicates that the dyeing uniformity is poor and the fabric has slight white exposure.

[0065] 3 points: Indicates that the dyeing uniformity is average, the fabric has a small color difference, and there are no obvious defects.

[0066] 4 points: Indicates good dyeing uniformity, uniform color of the fabric, and it is difficult to distinguish defects.

[0067] 5 points: Indicates excellent dyeing uniformity, the fabric color is completely uniform, and there is no color difference.

[0068] Color saturation: 1 point: Indicates that the dyeing saturation is extremely low, the color is very dull, the fabric looks old, and the visual effect is poor.

[0069] 2 points: Indicates that the dyeing saturation is low, the color is lighter, the fabric looks older, and the visual effect is poor.

[0070] 3 points: Indicates that the dyeing saturation is average, the color is moderate, the fabric does not look old, and the visual effect is average.

[0071] 4 points: Indicates that the dyeing saturation is high, the color is comfortable, the fabric is vibrant, and the visual effect is better.

[0072] 5 points: Indicates that the dyeing saturation is extremely high, the color makes people very comfortable, the fabric is very vibrant, and the visual effect is excellent.

[0073] The above test results are shown in Table 1.

[0074] Table 1: Specifically combined with the data analysis of Table 1, it can be seen that the dyeing process of Examples 1-7 performs well in terms of color fastness to washing and color fastness to perspiration, indicating that the nylon-ammonia dyed fabrics prepared in Examples 1-7 of the present application have high color fastness. In terms of dyeing uniformity, the dyeing uniformity and dyeing saturation scores of Examples 1-7 are good, indicating that the nylon-ammonia dyed fabrics prepared in Examples 1-7 of the present application have good dyeing uniformity and high dyeing saturation.

[0075] Specifically combined with the analysis of Example 1 and Comparative Examples 1-4, Comparative Examples 1-4 replaced secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose, respectively. It can be seen that in the composition of the leveling agent, the synergistic effect of secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose plays a key role in improving the dyeing saturation and color fastness, and can enhance the binding force between the dye and the nylon-spandex fiber, thereby improving the dyeing uniformity, saturation and color fastness.

[0076] Specifically combined with the analysis of Example 1 and Example 4, Example 4 uses BSFFIX of Argo Chemicals (China) Co., Ltd. as a fixing agent, and Example 1 performs well in terms of dyeing uniformity, saturation and color fastness. It can be seen that different fixing agents have different effects on the dyeing effect. Under the dyeing process of the present application, 3-chloro-2-hydroxypropyltrimethylammonium chloride is selected as the fixing agent, which can have a better synergistic effect with the leveling agent composed of secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose, and better improve the dyeing uniformity, saturation and color fastness of brocade ammonia dyed fabrics.

[0077] In combination with Example 1 and Comparative Example 5, the leveling agent was replaced with water in equal amounts in Comparative Example 5. The experimental results further confirmed that the leveling agent composed of secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose not only helps to evenly distribute the dye during the dyeing process, but also cooperates with 3-chloro-2-hydroxypropyltrimethylammonium chloride to significantly improve the color fixation effect of nylon-ammonia dyed fabrics, thereby improving the overall dyeing quality.

[0078] Specifically analyzing in combination with Example 1 and Examples 5-7, the difference between Example 1 and Example 5-7 is that the amount of dye used is inconsistent. Despite the different amounts of dye used, Example 1 and Example 5-7 perform well in terms of dyeing uniformity and dyeing saturation, which indicates that the dyeing process of the present application has good adaptability, maintains good dyeing quality at different dye amounts, and saves dye costs. It also further verifies that the leveling agent composed of secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose used in the present application can well improve the dyeing uniformity and saturation of nylon-ammonia-dyed fabrics during the dyeing process.

[0079] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A dyeing process for improving dyeing saturation and color fastness, characterized in that: The following steps are involved: Step 1: Slowly add an appropriate amount of soft water to the dye, then add 40%-60% by weight of the leveling agent, fully dissolve and stir until mixed evenly to obtain the dye solution; Step 2: Pump a certain amount of soft water into the dye vat, and add nylon-spandex fabric and the remaining leveling agent under the drive of water flow, then pump the dye solution into the dye vat, and control the amount of water so that the bath ratio of nylon-spandex fabric is 1:(15-30), then heat it to 80-85℃ at a heating rate of 2-3℃ / min, and keep it warm for 10-20min; Step 3: Add pH regulator to the dye vat, then heat it to 100-105°C at a heating rate of 0.5-2°C / min, keep it warm for 30-35 minutes, then cool it to below 40°C at a cooling rate of 2-3°C / min, drain the water, and obtain the primary dyed fabric; Step 4: Continue to add appropriate amount of soft water to the dye vat so that the bath ratio of the primary dyed fabric is 1: (15-30), then add pH regulator, then heat up to 80-85°C at a heating rate of 3-4°C / min, then add color fixing agent to the dye vat, the adding time is controlled within 8-12min, keep warm for 25-30min, finally cool down to below 40°C at a cooling rate of 2.5-3°C / min, drain, and get color fixing wet cloth; Step 5: After the color-fixing wet cloth is loosened, dried and shaped, the nylon-ammonia dyed fabric is obtained; The leveling agent is a mixture of secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose, and its usage is 1%-3% of the mass of the nylon-spandex fabric.

2. A dyeing process for improving dyeing saturation and color fastness according to claim 1, characterized in that: The mass ratio of the secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose is (30-40): (20-40): (20-30): (10-20).

3. A dyeing process for improving dyeing saturation and color fastness according to claim 1, characterized in that: The mass ratio of the secondary alcohol polyoxyethylene ether, calcium lignin sulfonate, soapberry fruit extract and hydroxypropyl cellulose is 35:25:25:

15.

4. A dyeing process for improving dyeing saturation and color fastness according to claim 1, characterized in that: The pH adjuster in step 3 is acetic acid, and the pH adjuster adjusts the pH value to 4-5.

5. A dyeing process for improving dyeing saturation and color fastness according to claim 1, characterized in that: The dye is a weak acid dye, and the dosage of the weak acid dye is 0.1%-5% of the mass of the nylon-spandex grey cloth.

6. A dyeing process for improving dyeing saturation and color fastness according to claim 1, characterized in that: The color fixing agent is 3-chloro-2-hydroxypropyltrimethylammonium chloride, and its usage is 10%-20% of the mass of the nylon-spandex fabric.

7. A dyeing process for improving dyeing saturation and color fastness according to claim 1, characterized in that: The pH regulator in step 4 is DL-hydroxysuccinic acid, and the pH regulator adjusts the pH value to 4-5.

8. A nylon-ammonia dyed fabric, characterized in that: The dyeing process for improving dyeing saturation and color fastness as described in any one of claims 1 to 7 is adopted for preparation.

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