Dipping method for energy-saving short process brocade knitted fabric with low-temperature dyeing and medium-temperature discharge

Abstract

The application discloses a low-temperature dyeing and medium-temperature discharging energy-saving short-process brocade knitting fabric dip dyeing method, and belongs to the technical field of knitting fabric printing and dyeing processing. The brocade knitting fabric is put into a dyeing solution, the dyeing solution is heated to 75-85 DEG C and kept for 25-35 min, then the temperature is reduced to 55-65 DEG C, and the sample is taken for color matching; after the color of the knitting fabric is qualified, the dyeing solution is not discharged; a dispersing agent, a bath anti-wrinkle agent and an acid fixing agent are added into the residual dyeing solution, and acid is added to adjust the pH to 4.5, so that a fixing solution is obtained, and the fixing solution is heated to 65-75 DEG C and kept for 15-25 min, and then the fixing solution is directly discharged; the knitting fabric is put into clean water for washing and taking out, and dip dyeing is completed through after-setting. The application has the beneficial effects that: under the premise of using traditional overflow dyeing cylinder equipment and ensuring the printing and dyeing quality of the fiber brocade knitting fabric, the energy consumption is effectively reduced, the water is saved, and the production process is shortened through reducing the dyeing temperature and discharging at medium temperature, and the method is very suitable for the printing and dyeing processing of high-polyurethane content brocade super-fine fiber knitting fabric.

Description

Technical Field

[0001] This invention relates to the field of knitted fabric printing and dyeing technology, and more specifically, to an energy-saving, short-process dyeing method for high-spandex-content microfiber nylon-spandex knitted fabrics with low-temperature dyeing and medium-temperature emissions. Background Technology

[0002] The textile printing and dyeing industry currently relies heavily on wet processing, resulting in significant water, steam, and electricity consumption. Conserving water, steam, and electricity, and reducing wastewater discharge are responsibilities that enterprises should undertake. Clean production must comply with national policies promoting low-carbon, water-saving, and emission-reduction practices, while also meeting the factory's requirements for low cost and high quality.

[0003] Currently, to achieve water conservation, emission reduction, and energy saving in the dyeing and printing of knitted fabrics made of nylon and spandex, the following aspects are mainly addressed: ① low liquor ratio; ② new dyeing and finishing equipment; ③ wastewater purification and recycling; ④ research on new dyeing media to replace water; ⑤ adjustment of dyeing and printing production processes. Among these, adjusting the dyeing and printing production processes is a commonly used method for water conservation and emission reduction by dyeing and printing companies.

[0004] For example, patent application CN112301764A discloses a short-process dyeing method for nylon / spandex high-elastic fabric, comprising the following steps: ① refining the nylon / spandex high-elastic fabric; ② neutralizing the nylon / spandex high-elastic fabric with acid; ③ dyeing the nylon / spandex high-elastic fabric, followed by acid fixation without draining the dye solution; the acid fixation agent used is DM-2537; ④ softening the nylon / spandex high-elastic fabric; the acid fixation temperature in step ③ is 75-85℃, and the time is 15-30 minutes; the dosage of the acid fixation agent in step ③ is 2-5 g / L. While it discloses the direct fixation method without draining the dye solution after dyeing the nylon / spandex high-elastic fabric, the dyeing temperature is 98℃, and the wastewater discharge temperature is not recorded. Although this achieves energy saving and reduction, there is still room for improvement.

[0005] In view of this, the inventors conducted in-depth research to address this need, which led to the present invention. Summary of the Invention

[0006] To overcome the problems of large wastewater discharge and insignificant water-saving and emission-reduction effects in existing dyeing and finishing processes, this invention employs a low-temperature immersion dyeing short-process production technology under traditional dyeing and finishing equipment conditions. This achieves low-temperature, energy-saving, and short-process production of nylon-spandex knitted fabrics, meeting quality targets such as no color bleeding, no creases, no abrasions, and satisfactory color fastness. It also achieves water-saving, energy-saving, and emission-reduction effects. It is highly suitable for dyeing and finishing high-spandex-content microfiber nylon-spandex knitted fabrics. The specific technical solution is as follows:

[0007] A low-temperature dyeing, medium-temperature emission, energy-saving, short-process dyeing method for nylon-spandex knitted fabrics includes the following steps:

[0008] Step 1: Place the nylon-spandex knitted fabric into the dye bath. Heat the dye bath to 75-85℃ and keep it at that temperature for 25-35 minutes. Then cool it down to 55-65℃ and take a sample for color matching. Do not drain the dye bath after the color of the knitted fabric is qualified.

[0009] Step 2: Add dispersant, anti-wrinkle agent and acidic fixing agent to the dye residue solution, and adjust the pH to 4.5 with acid to obtain the fixing solution. Heat the solution to 65-75℃ and keep it at that temperature for 15-25 minutes before draining it directly.

[0010] Step 3: Wash the knitted fabric in clean water, then finish the dyeing process by shaping.

[0011] While ensuring the printing and dyeing quality of fiber nylon-spandex knitted fabrics using traditional overflow dyeing equipment, the goal of reducing energy consumption and saving water is effectively achieved by lowering the dyeing temperature, shortening the production process, and implementing medium-temperature emissions.

[0012] The in-bath anti-wrinkle agent is mainly composed of a mixture of polyacrylic acids. It prevents creases from forming on high-spandex-content microfiber nylon-spandex knitted fabrics when directly discharged at 70°C after dye fixation. This is because discharging the dye bath at 70°C involves a direct temperature drop from 70°C to room temperature (28°C), creating a significant temperature difference that can cause creases in high-spandex-content nylon-spandex knitted fabrics. Traditional old-process dye baths discharged at 55°C did not require in-bath anti-wrinkle agents because production showed that directly cooling the dye bath from 55°C to room temperature resulted in very few creases on the fabric due to this temperature difference.

[0013] Preferably, the nylon in the knitted fabric is microfiber. Microfiber is also known as microfiber, fine denier fiber, ultrafine fiber, etc. Generally, fibers with a fineness of less than 0.3 denier (diameter of 5 micrometers) are called microfiber. Microfiber nylon-spandex knitted fabric has a wide range of uses. It has a soft and smooth surface. High-end fashion, jackets, T-shirts, underwear, skirts and pants made from this fabric are cool and comfortable, absorbent and do not stick to the body. High-grade artificial suede made from microfiber has the appearance, feel and style of genuine leather, but at a low price. Cleaning cloths made from it have excellent cleaning effect and can wipe various glasses, film and television equipment and precision instruments without damaging the mirror surface. Microfiber can also be made into ultra-high-density fabrics with extremely smooth surfaces. It can be used to make sportswear for skiing, skating, swimming and other sports to reduce resistance and help athletes achieve good results. It can also be used in filtration, medical and health care, labor protection and many other fields.

[0014] Preferably, the spandex content in the knitted fabric accounts for more than 20% of the total mass of the knitted fabric.

[0015] Preferably, by weight percentage, the knitted fabric comprises 60-80% nylon and 20-40% spandex; and the nylon is (15-25)D / (30-40)F nylon filament round filament, and the spandex is 15-25D chlorine-resistant spandex.

[0016] Under the premise of the same fabric printing and dyeing quality, it meets the requirements of water conservation, reduces wastewater discharge, saves the heat energy and production time required to heat the dye liquor from about 80℃ to 98℃, and does not discharge the residual fixing liquor without cooling, saving time and cooling water. At the same time, it meets the requirement of reducing oligomers. By adjusting the process and shortening the production process, it can effectively prevent defects and abnormalities such as color spots, creases, scratches, and stains that are easily produced in the production of high spandex content microfiber nylon-spandex knitted fabrics in ordinary dyeing vats at low temperature and short process.

[0017] Preferably, in step one, the nylon-spandex knitted fabric is placed in a dye bath at a temperature of 25-30°C at a bath ratio of 1:(10-12).

[0018] Preferably, in step one, a dyeing accelerator, a leveling agent, an acid-releasing agent, an oil-removing agent, and a weakly acidic dye are added before the dye liquor is heated.

[0019] Preferably, in step one, before heating the dye bath, add 2.0-8.0% owf of a dyeing accelerator, 2.0-3.0% owf of a leveling agent, 1.0-1.5 g / l of an acid-releasing agent, 0.8-1.2 g / l of an oil-removing agent, and 0-0.8% owf of a weakly acidic dye.

[0020] Preferably, the dyeing accelerator comprises, by mass percentage, the following components: 45.0-50.0% sodium acetate, 22.0-25.0% magnesium gluconate and 22.0-25.0% sodium gluconate, which enable ordinary weakly acidic dyes to be fully applied to nylon-ammonia knitted fabrics at around 80°C.

[0021] Using a special dyeing accelerator, weakly acidic and neutral dyes can be applied at around 80℃ with high dye uptake. However, this accelerator has certain limitations; the color is not very stable when dyeing dark-colored microfiber knitted fabrics with high spandex content (owf≥1.5%), and further experimental improvements are needed. Currently, the low-temperature short-process dyeing technology is most suitable for dyeing medium-light colored microfiber nylon-spandex knitted fabrics, and the process formulation has high reproducibility when the total amount of weakly acidic dyes used is within the owf range of 0-0.8%.

[0022] Preferably, in step one, the temperature is increased to 75-85℃ at a rate of 1.0℃ / min and held for 25-35 minutes, and then decreased to 55-65℃ at a rate of 2.0℃ / min for sampling and color matching.

[0023] Preferably, in step two, 0.3-0.8 g / L of dispersant, 2.0-4.0% of in-bath anti-wrinkle agent, and 2.0-3.0% of acidic fixing agent are added, and 0-0.5 g / L of acetic acid is added to adjust the pH to 4.5. The feeding time is 3-8 min, and after running for another 3-8 min, the temperature is raised to 65-75℃ at a rate of 2.5℃ / min and kept at that temperature for 15-25 min before directly draining the liquid.

[0024] It should be noted that before the workshop verification, some people used 80℃ for sampling and discharge of dye liquor, which has the following problems: First, it poses a safety hazard. At 80℃, the dyeing vat is under considerable pressure. Opening the vat cover at this temperature could easily cause the 80℃ residual dye liquor to spray out and injure people, potentially leading to a safety accident. Second, it is not suitable for dyeing and printing on high-spandex-content microfiber nylon-spandex knitted fabrics. Discharging the 80℃ residual dye liquor directly to room temperature creates a large temperature difference. High-spandex-content microfiber nylon-spandex fabrics will develop creases due to such a large temperature change in a short period of time. Therefore, the process of discharging residual dye liquor at 80℃ needs to be optimized. Third, it is also not permissible to open the cover for sampling and discharge of ordinary overflow dyeing vats operating at 80℃, as this is a violation of regulations.

[0025] Beneficial effects:

[0026] The beneficial effects of adopting the technical solution of this invention are as follows:

[0027] (1) Under the premise of ensuring the printing and dyeing quality of fiber nylon-spandex knitted fabrics by using traditional overflow dyeing equipment, the goal of reducing energy consumption and saving water is effectively achieved by reducing dyeing temperature, shortening the production process, and medium-temperature emission.

[0028] (2) Under the premise of the same fabric printing and dyeing quality, it meets the requirements of saving water, reducing sewage discharge, saving the heat energy and production time required to heat the dye liquor from about 80℃ to 98℃, and the residual color fixing liquor is not cooled down and discharged, saving time and cooling water. At the same time, it meets the requirements of reducing oligomers. By adjusting the process and shortening the production process, it can effectively prevent the abnormal defects such as color spots, creases, scratches and stains that are easy to be produced in the production of high spandex content microfiber nylon-spandex knitted fabrics in ordinary dyeing vats at low temperature and short process.

[0029] (3) To reduce water and heat consumption during the dyeing and printing of nylon-spandex microfiber knitted fabrics with high spandex content (spandex mass exceeding 20%). High spandex content nylon-spandex knitted fabrics require high elasticity, significantly different from ordinary nylon-spandex knitted fabric dyeing and printing. Because high spandex content easily leads to creases, abrasions, color variations, and oil stains during dyeing and printing, the process flow cannot be blindly shortened, nor can water consumption be reduced indefinitely. The immersion dyeing process in this patent ensures stable quality in the dyeing and printing of high spandex content nylon-spandex knitted fabrics.

[0030] (4) Before dyeing, the chemical fiber knitted fabric is washed with water to remove oil, so as to achieve relaxation and oil removal. After the nylon-spandex knitted fabric is degreased and pre-shaped, it is directly put into the dyeing vat. The dyeing vat degreasing and dyeing one-bath method recorded in previous relevant literature is completely unnecessary in this patent process. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 This is a flow chart of the preferred dyeing process for nylon-spandex knitted fabric of the present invention;

[0033] Figure 2 This is a graph showing the dyeing temperature rise and fall process in Example 1;

[0034] Figure 3 This is a graph showing the temperature rise and fall process of color fixing and cleaning in Example 1;

[0035] Figure 4 This is a graph showing the dyeing temperature rise and fall process in Comparative Example 1;

[0036] Figure 5 This is a graph showing the temperature rise and fall process curves of the water washing process in Comparative Example 1.

[0037] Figure 6 This is a temperature rise and fall curve of the color fixing and washing process in Comparative Example 1. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of 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, not all of them. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0039] like Figure 1 As shown, the energy-saving short-process dyeing method for nylon-spandex knitted fabrics with low-temperature dyeing and medium-temperature emissions includes the following steps:

[0040] Step S101: Place the nylon-spandex knitted fabric into the dye bath, heat the dye bath to 75-85℃ and keep it at that temperature for 25-35 minutes, then cool it down to 55-65℃ and take a sample for color matching. Do not drain the dye bath after the color of the knitted fabric is qualified.

[0041] Step S102: Add dispersant, anti-wrinkle agent and acidic fixing agent to the dye residue solution, and adjust the pH to 4.5 with acid to obtain fixing solution. Heat the solution to 65-75℃ and keep it at that temperature for 15-25 minutes before draining it directly.

[0042] Step S103: Wash the knitted fabric in clean water, and then finish the dyeing process by setting the fabric.

[0043] While ensuring the printing and dyeing quality of fiber nylon-spandex knitted fabrics using traditional overflow dyeing equipment, the goal of reducing energy consumption and saving water is effectively achieved by lowering the dyeing temperature, shortening the production process, and implementing medium-temperature emissions.

[0044] The in-bath anti-wrinkle agent is mainly composed of a mixture of polyacrylic acids. It prevents creases from forming on high-spandex-content microfiber nylon-spandex knitted fabrics when directly discharged at 70°C after dye fixation. This is because discharging the dye bath at 70°C involves a direct temperature drop from 70°C to room temperature (28°C), creating a significant temperature difference that can cause creases in high-spandex-content nylon-spandex knitted fabrics. Traditional old-process dye baths discharged at 55°C did not require in-bath anti-wrinkle agents because production showed that directly cooling the dye bath from 55°C to room temperature resulted in very few creases on the fabric due to this temperature difference.

[0045] In a preferred embodiment, the nylon in the knitted fabric is a microfiber.

[0046] In a preferred embodiment, the spandex content in the knitted fabric accounts for more than 20% of the total mass of the knitted fabric.

[0047] In a preferred embodiment, the knitted fabric comprises 60-80% nylon and 20-40% spandex by weight percentage; and the nylon is (15-25)D / (30-40)F nylon filament round filament, and the spandex is 15-25D chlorine-resistant spandex.

[0048] In a preferred embodiment, in step S101, the nylon-spandex knitted fabric is placed in a dye bath at a temperature of 25-30°C at a bath ratio of 1:(10-12).

[0049] In a preferred embodiment, in step S101, a dyeing accelerator, a leveling agent, an acid-releasing agent, an oil-removing agent, and a weakly acidic dye are added before the dye bath is heated.

[0050] In a preferred embodiment, in step S101, before heating the dye bath, add a dyeing accelerator of 2.0-8.0% owf, a leveling agent of 2.0-3.0% owf, an acid-releasing agent of 1.0-1.5 g / l, an oil-removing agent of 0.8-1.2 g / l, and a weakly acidic dye of 0-0.8% owf.

[0051] In a preferred embodiment, the dyeing accelerator comprises, by weight percentage, the following components: 45.0-50.0% sodium acetate, 22.0-25.0% magnesium gluconate and 22.0-25.0% sodium gluconate; its function is to promote the full dyeing of common weakly acidic dyes on nylon-ammonia knitted fabrics at around 80°C.

[0052] In a preferred embodiment, in step S101, the temperature is increased to 75-85℃ at a rate of 1.0℃ / min and held for 25-35min, and then decreased to 55-65℃ at a rate of 2.0℃ / min for sampling and color matching.

[0053] In a preferred embodiment, in step S102, 0.3-0.8 g / L of dispersant, 2.0-4.0% of in-bath anti-wrinkle agent, and 2.0-3.0% of acidic fixing agent are added, and 0-0.5 g / L of acetic acid is added to adjust the pH to 4.5. The feeding time is 3-8 min, and after running for another 3-8 min, the temperature is raised to 65-75℃ at a rate of 2.5℃ / min and kept at that temperature for 15-25 min before directly draining the liquid.

[0054] The beneficial effects of the dyeing process in this embodiment will be further evaluated below through examples and comparative examples.

[0055] Example 1:

[0056] like Figure 2 and 3 As shown, a dyeing method includes the following steps:

[0057] Step 1: Place the nylon-spandex knitted fabric into a dye bath at 28℃ at a liquor ratio of 1:(10-12). Add 2.0-8.0% owf dyeing accelerator, 2.0-3.0% owf leveling agent, 1.0-1.5 g / l acid release agent, 0.8-1.2 g / l oil remover, and 0-0.8% owf weak acid dye to the dye bath. Heat the dye bath to about 80℃ at a rate of 1.0℃ / min and hold for 30 minutes. Then cool it down to about 60℃ at a rate of 2.0℃ / min and take a sample for color matching. Do not drain the dye bath after the knitted fabric has passed the color test.

[0058] The knitted fabric comprises 72% nylon and 28% spandex; wherein the nylon is 20D / 34F nylon filament round filament and the spandex is 20D chlorine-resistant spandex.

[0059] The dyeing accelerator includes the following components: 45.0-50.0% sodium acetate, 22.0-25.0% magnesium gluconate and 22.0-25.0% sodium gluconate. Its function is to promote the full dyeing of ordinary weak acid dyes on nylon-ammonia knitted fabrics at around 80°C.

[0060] Step 2: Add 0.5 g / L of dispersant, 2.0-4.0% of in-bath anti-wrinkle agent, and 2.0-3.0% of acidic fixing agent to the dye residue solution, and add 0-0.5 g / L of acetic acid to adjust the pH to 4.5. The addition time is 5 min, and after running for another 5 min, the temperature is increased to 70℃ at a rate of 2.5℃ / min and kept at this temperature for 20 min before directly draining the solution.

[0061] Step 3: Wash the knitted fabric in clean water, then finish the dyeing process by shaping.

[0062] Here, the dyeing and color-fixing process requires two tanks of water, with a total duration of approximately 147 minutes, including about 103 minutes for dyeing and about 44 minutes for color fixing and rinsing.

[0063] Comparative Example 1:

[0064] like Figure 4-6 As shown, a dyeing method includes the following steps:

[0065] Step 1: Place the nylon-spandex knitted fabric into a dye bath at 28℃ at a bath ratio of 1:(10-12). Add 2.5-3.0% owf leveling agent, 1.0-1.5 g / l acid release agent, 0.8-1.2 g / l oil remover, and 0-0.8% owf weak acid dye to the dye bath. Heat the dye bath to about 98℃ at a rate of 1.0℃ / min and keep it at that temperature for 30 minutes. Then, cool it down to about 60℃ at a rate of 2.0℃ / min and take a sample for color matching. After the color is qualified, cool it down to 55℃ and drain the residual liquid.

[0066] The knitted fabric comprises 72% nylon and 28% spandex; wherein the nylon is 20D / 34F nylon filament round filament and the spandex is 20D chlorine-resistant spandex.

[0067] Step 2: Add clean water and heat to 55℃ for 20 minutes. After rinsing, drain the residual liquid at 50℃. Add clean water again, add 0.5 g / L of dispersant and 2.0-3.0% owf of acidic fixing agent at room temperature, and add 0-0.5 g / L of acetic acid to adjust the pH to 4.5. The addition time is 5 minutes. Run for 5.0 minutes, heat to 70℃ at a rate of 2.5℃ / min and hold for 20 minutes. After fixing and holding at this temperature, cool down to 55℃ at a rate of 2.0℃ / min and drain the residual liquid.

[0068] Step 3: Wash the knitted fabric in clean water, then finish the dyeing process by shaping.

[0069] Here, the dyeing and color-fixing process requires four tanks of water, with a total duration of approximately 245 minutes. The dyeing process takes about 125 minutes, the rinsing process takes about 50 minutes, and the color-fixing and rinsing process takes about 70 minutes.

[0070] Based on a dyeing rate of 120kg, in terms of energy saving, the low-temperature, short-process method in Example 1 can save approximately 98 minutes, resulting in a time saving of about 40% in the process. Considering the unit area weight of the greige fabric and the fixed model of the dyeing vat, actual production requires a 200kg overflow dyeing vat. Based on a power consumption of 26 kW / hour for a 200kg overflow dyeing vat, the theoretical energy saving is 42 kW. This saves the heating energy required to raise 1200kg of water from room temperature to 60℃, and the heating energy required to raise the temperature from 80℃ to 98℃. It is generally considered that the specific heat of water at constant pressure is 4.2 KJ / kg·℃, and the energy formula Q=cmΔT shows that heat can be saved.

[0071] Table 1 Comparison of energy requirements for each process in Example 1 and Comparative Example 1

[0072]

[0073] Note: The specific heat of water at constant pressure is 4.2 KJ / KG˙℃, the liquor ratio is 1:10, 120 kg of knitted fabric is dyed, the mass of water in each vat is m=1200 kg, Q=cmΔT.

[0074]

[0075] In terms of water conservation and wastewater reduction, the traditional process requires 4 tanks of water with a liquor ratio of 1:10, and actually requires 4800 kg of water. The new process requires 2 tanks of water with a liquor ratio of 1:10, and actually requires 2400 kg of water. The new low-temperature dyeing short-process method can save 2400 kg of water. According to the calculation, it saves 50% of water and reduces emissions by 50%.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A low-temperature dyeing, medium-temperature emission, energy-saving, short-process dyeing method for nylon-spandex knitted fabrics, characterized in that, Includes the following steps: Step 1: Place the nylon-spandex knitted fabric into the dye bath. Add 2.0-8.0% owf of dyeing accelerator, 2.0-3.0% owf of leveling agent, 1.0-1.5 g / L of acid-releasing agent, 0.8-1.2 g / L of degreasing agent, and 0-0.8% owf of weakly acidic dye to the dye bath. Heat the dye bath to 75-85℃ and keep it at that temperature for 25-35 minutes, then cool it down to 55-65℃ and take a sample for color matching. Do not drain the dye bath after the knitted fabric color is qualified. The dyeing accelerator, by mass percentage, includes the following components: 45.0-50.0% sodium acetate, 22.0-25.0% magnesium gluconate, and 22.0-25.0% sodium gluconate. Step 2: Add dispersant, anti-wrinkle agent and acidic fixing agent to the dye residue solution, and adjust the pH to 4.5 with acid to obtain the fixing solution. Heat the solution to 65-75℃ and keep it at that temperature for 15-25 minutes before draining it directly. Step 3: Wash the knitted fabric in clean water, then finish the dyeing process by shaping.

2. The low-temperature dyeing and medium-temperature emission energy-saving short-process nylon-spandex knitted fabric impregnation method according to claim 1, characterized in that, The nylon in the knitted fabric is a microfiber.

3. The low-temperature dyeing and medium-temperature emission energy-saving short-process nylon-spandex knitted fabric impregnation method according to claim 1, characterized in that, The spandex content in the knitted fabric accounts for more than 20% of the total mass of the knitted fabric.

4. The low-temperature dyeing and medium-temperature emission energy-saving short-process nylon-spandex knitted fabric impregnation method according to claim 1, characterized in that, The knitted fabric comprises 60-80% nylon and 20-40% spandex by weight percentage; and the nylon is (15-25)D / (30-40)F nylon filament round filament, and the spandex is 15-25D chlorine-resistant spandex.

5. The low-temperature dyeing and medium-temperature emission energy-saving short-process nylon-spandex knitted fabric impregnation method according to claim 1, characterized in that, In step one, the nylon-spandex knitted fabric is placed in a dye bath at a temperature of 25-30℃ at a bath ratio of 1:(10-12).

6. The low-temperature dyeing and medium-temperature emission energy-saving short-process nylon-spandex knitted fabric impregnation method according to claim 1, characterized in that, In step one, the temperature is increased to 75-85℃ at a rate of 1.0℃ / min and held for 25-35 minutes, then decreased to 55-65℃ at a rate of 2.0℃ / min for sampling and color matching.

7. The low-temperature dyeing and medium-temperature emission energy-saving short-process nylon-spandex knitted fabric impregnation method according to claim 1, characterized in that, In step two, add 0.3-0.8 g / L of dispersant, 2.0-4.0% of in-bath anti-wrinkle agent, and 2.0-3.0% of acidic fixing agent, and add 0-0.5 g / L of acetic acid to adjust the pH to 4.

5. The feeding time is 3-8 min. After running for another 3-8 min, raise the temperature to 65-75℃ at a rate of 2.5℃ / min and keep it at that temperature for 15-25 min before draining the liquid directly.

Images