Energy-saving dip dyeing method for knitted fabric

Abstract

The invention relates to the technical field of textile dyeing, and particularly discloses an energy-saving dip dyeing method for knitted fabric. An energy-saving dip dyeing method for a knitted fabric comprises the following steps: pretreatment: immersing the knitted fabric in a pretreatment solution, soaking at 30-50 DEG C, and then washing to obtain a pretreated knitted fabric; wherein the raw materials of the pretreatment liquid comprise the following components in parts by weight: 90-110 parts of deionized water, 1-5 parts of a surfactant, 0.5-2 parts of an electrolyte, 0.5-3 parts of a solubilizer and 0.5-2 parts of a softening agent; dyeing: putting the pretreated knitted fabric into a dye solution, soaking at 20-30 DEG C, taking out, washing with water, and carrying out heat setting to obtain a dyed knitted fabric; wherein dye in the dye liquid is prepared from the following components in parts by weight: 20 to 30 parts of reactive dye, 10 to 20 parts of penetrant, 5 to 15 parts of regulator, 10 to 20 parts of reserve salt and 0.1 to 1 part of buffering agent.

Description

Technical Field

[0001] The present application relates to the technical field of textile dyeing, and in particular to an energy-saving dyeing method for knitted fabrics. Background Art

[0002] Dyeing of knitted fabrics is an important part of the textile industry. Traditional dyeing processes usually require high temperatures to promote the combination of dyes and fibers, which not only consumes a lot of energy but also may pollute the environment. With the improvement of environmental awareness and technological advancement, the development of new technologies and new materials that can effectively dye at lower temperatures has become a focus of the industry. Although some low-temperature dyeing technologies can dye knitted fabrics, the dyeing effect is not good. Summary of the invention

[0003] In order to improve the dyeing effect of knitted fabrics at low temperatures, the present application provides an energy-saving dyeing method for knitted fabrics.

[0004] The present application provides an energy-saving dyeing method for knitted fabrics, which adopts the following technical solution: A knitted fabric energy-saving dip-dyeing method comprises the following steps: Pretreatment: immersing the knitted fabric in a pretreatment solution at 30-50°C, and then washing to obtain a pretreated knitted fabric; wherein the raw materials of the pretreatment solution include the following components in parts by weight: 90-110 parts of deionized water, 1-5 parts of a surfactant, 0.5-2 parts of an electrolyte, 0.5-3 parts of a solubilizer, and 0.5-2 parts of a softener; Dyeing: putting the pretreated knitted fabric into the dye solution, soaking it at 20-30°C, taking it out, washing it with water, and heat-setting it to obtain a dyed knitted fabric; wherein the raw materials of the dye in the dye solution include the following components in parts by weight: 20-30 parts of active dyes, 10-20 parts of penetrants, 5-15 parts of regulators, 10-20 parts of resist salts, and 0.1-1 parts of buffers.

[0005] By adopting the above technical scheme, the knitted fabric is first immersed in the pretreatment liquid, the surfactant in the pretreatment liquid reduces the surface tension of the liquid, enhances the adsorption capacity of the dye on the fiber, thereby improving the dyeing uniformity and color brightness, the electrolyte improves the stability of the dye solution, prevents the aggregation and precipitation of the dye particles, and further improves the dyeing uniformity, the solubilizer increases the solubility of the dye in deionized water, so that the dye can better penetrate into the fiber, improves the depth and fastness of the dyeing, the softener improves the fiber surface tension, reduces the friction coefficient between fibers, and improves the subsequent dyeing effect; during the dyeing process, the penetrant improves the penetration efficiency of the dye into the knitted fabric, thereby improving the dyeing uniformity and dyeing effect, the regulator improves the dye uptake and fixation effect of the dye, the anti-dyeing salt can promote the combination of the dye and the textile fiber, and improve the dyeing uniformity, the buffer adjusts and maintains the pH value of the dye solution, and ensures that the dyeing process is carried out in a suitable acid-base environment, thereby improving the dyeing effect of the knitted fabric, and the pretreatment and dyeing are both carried out at low temperature, which is energy-saving and environmentally friendly.

[0006] In a specific embodiment, the surfactant includes one or a mixture of alkyl glycoside and fatty alcohol polyoxyethylene ether.

[0007] By adopting the above technical scheme, when alkyl polyglycoside is used as a surfactant, the deionized water-philic part and the deionized water-repelling part in its molecular structure are balanced, which can effectively reduce the surface tension of the solution and increase the wetting effect of the dye on the fabric; when fatty alcohol polyoxyethylene ether is used as a surfactant, the deionized water-philic part and the deionized water-repelling part in its molecular structure are also well balanced, which can also effectively reduce the surface tension of the solution and increase the dispersibility and permeability of the dye.

[0008] In a specific embodiment, the electrolyte includes a mixture of sodium chloride and sodium sulfate.

[0009] By adopting the above technical solution, sodium chloride has good solubility, can effectively improve the dye bath environment, improve the uniformity and fastness of dyeing, and sodium sulfate can increase the ionic strength in the dye bath and provide a more stable dyeing environment. Therefore, the combination of the two improves the dyeing effect.

[0010] In a specific embodiment, the solubilizer includes ethylene glycol, propylene glycol, or a mixture of the two.

[0011] By adopting the above technical solution, the polarity and non-polarity of the ethylene glycol molecule are balanced with each other, which can effectively disperse and dissolve the dye; the structure of propylene glycol is similar to that of ethylene glycol, and it can also improve the solubility of the dye, and in some cases, the dissolution effect of propylene glycol may be better, which can further improve the dyeing effect.

[0012] In a specific embodiment, the softener includes sodium dodecylbenzene sulfonate.

[0013] By adopting the above technical solution, sodium dodecylbenzene sulfonate not only brings about a softening effect, but also cooperates with sodium sulfate in the electrolyte to effectively promote the diffusion and adsorption of dye molecules.

[0014] In a specific embodiment, the raw materials of the pretreatment liquid further include disodium hydrogen phosphate, so that the pH of the pretreatment liquid is 5.5.

[0015] By adopting the above technical solution, the addition of disodium hydrogen phosphate can further enhance the binding force between the dye and the fabric.

[0016] In a specific embodiment, the penetrant includes a mixture of polyoxyethylene fatty alcohol ether and alkylphenol polyoxyethylene ether.

[0017] By adopting the above technical scheme, polyoxyethylene fatty alcohol ether and alkylphenol polyoxyethylene ether have good wettability and dispersibility, can significantly improve the penetration ability of dyes, and the combination of the two causes less damage to the fiber and will not affect the feel and appearance of the knitted fabric.

[0018] In a specific embodiment, the dye-resist salt includes sodium nitrate, ammonium phosphate or a mixture of the two.

[0019] In a specific embodiment, the buffer includes disodium hydrogen phosphate, potassium dihydrogen phosphate, or a mixture of the two.

[0020] By adopting the above technical solution, disodium hydrogen phosphate and potassium dihydrogen phosphate can form a stable buffer system in the dye solution to prevent excessive fluctuations in the pH value, thereby ensuring the smooth progress of the dyeing process.

[0021] In a specific embodiment, in the dyeing step: the pretreated knitted fabric is placed in the dye solution and immersed at 20-30° C. for 10-30 minutes.

[0022] In summary, the present application includes at least one of the following beneficial technical effects: 1. In the present application, the knitted fabric is first immersed in a pretreatment liquid. The surfactant in the pretreatment liquid reduces the surface tension of the liquid and enhances the adsorption capacity of the dye on the fiber, thereby improving the dyeing uniformity and color brightness. The electrolyte improves the stability of the dye solution, prevents the aggregation and precipitation of the dye particles, and further improves the dyeing uniformity. The solubilizer increases the solubility of the dye in deionized water, so that the dye can better penetrate into the fiber, improving the depth and fastness of the dyeing. The softener improves the fiber surface tension, reduces the friction coefficient between fibers, and improves the subsequent dyeing effect. During the dyeing process, the penetrant improves the penetration efficiency of the dye into the knitted fabric, thereby improving the dyeing uniformity and dyeing effect. The regulator improves the dye uptake and fixation effect of the dye. The anti-dyeing salt can promote the combination of the dye and the textile fiber and improve the dyeing uniformity. The buffer adjusts and maintains the pH value of the dye solution to ensure that the dyeing process is carried out in a suitable acid-base environment, thereby improving the dyeing effect of the knitted fabric. The pretreatment and dyeing are both carried out at low temperatures, which is energy-saving and environmentally friendly. 2. In addition to the softening effect, the sodium dodecylbenzene sulfonate in this application can also effectively promote the diffusion and adsorption of dye molecules when combined with the sodium sulfate in the electrolyte; 3. The polyoxyethylene fatty alcohol ether and alkylphenol polyoxyethylene ether in the present application have good wettability and dispersibility, can significantly improve the penetration ability of the dye, and the combination of the two causes less damage to the fiber and will not affect the feel and appearance of the knitted fabric. DETAILED DESCRIPTION

[0023] The present application is further described in detail below with reference to the embodiments.

[0024] All raw materials in the embodiment can be obtained commercially. Reactive dyes include but are not limited to a mixture of one or more of CIReactive Red 120, CIReactive Blue 19, and CIReactive Yellow 145, and CIReactive Yellow 145 is preferred in this application; surfactants include but are not limited to a mixture of one or two of alkyl glycosides and fatty alcohol polyoxyethylene ethers, and fatty alcohol polyoxyethylene ethers are preferred in this application; solubilizers include but are not limited to a mixture of one or two of ethylene glycol and propylene glycol, and propylene glycol is preferred in this application; dye-resist salts include but are not limited to a mixture of one or two of sodium nitrate and ammonium phosphate, and sodium nitrate is preferred in this application; buffers include but are not limited to a mixture of one or two of disodium hydrogen phosphate and potassium dihydrogen phosphate, and disodium hydrogen phosphate is preferred in this application. Example

[0025] Example 1 Embodiment 1 provides a knitted fabric energy-saving dip-dyeing method, comprising the following steps: Pretreatment: 1 kg of surfactant, 0.5 kg of electrolyte, 0.5 kg of solubilizer and 0.5 kg of softener are added into 90 kg of deionized water, and stirred and mixed evenly at 30°C to obtain a pretreatment solution; the knitted fabric is immersed in the pretreatment solution, and soaked at 30°C for 20 minutes, and then washed to obtain a pretreated knitted fabric; wherein the surfactant is fatty alcohol polyoxyethylene ether; the electrolyte is a mixture of sodium chloride and sodium sulfate, and the weight ratio of sodium chloride to sodium sulfate is 2:1; the solubilizer is propylene glycol; and the softener is sodium dodecylbenzene sulfonate; Dyeing: 20kg of active dye, 10kg of penetrant, 5kg of regulator, 10kg of resist salt and 0.1kg of buffer are stirred and mixed to obtain dye, and then the dye is added into deionized water, stirred and mixed to obtain dye solution at 20°C; wherein the concentration of the dye in the dye solution is 10g / L; wherein the penetrant is a mixture of polyoxyethylene fatty alcohol ether and alkylphenol polyoxyethylene ether, and the weight ratio of polyoxyethylene fatty alcohol ether to alkylphenol polyoxyethylene ether is 1:1; the regulator is sodium bicarbonate; the resist salt is sodium nitrate; and the buffer is disodium hydrogen phosphate; The pretreated knitted fabric is placed in the dye solution, immersed at 20° C. for 30 minutes, taken out, washed with water, and heat-set to obtain a dyed knitted fabric.

[0026] Example 2 The difference between Example 2 and Example 1 is that, pretreatment: 3 kg of surfactant, 1.2 kg of electrolyte, 1.7 kg of solubilizer, and 1.2 kg of softener are added to 100 kg of deionized water, and stirred and mixed evenly at 30°C to obtain a pretreatment solution; the knitted fabric is immersed in the pretreatment solution, soaked at 30°C for 20 minutes, and then washed to obtain a pretreated knitted fabric; wherein the surfactant is fatty alcohol polyoxyethylene ether; the electrolyte is a mixture of sodium chloride and sodium sulfate, and the weight ratio of sodium chloride to sodium sulfate is 2:1; the solubilizer is propylene glycol; the softener is sodium dodecylbenzene sulfonate; and the remaining steps are consistent with Example 1.

[0027] Example 3 The difference between Example 3 and Example 1 is that, pretreatment: 5 kg of surfactant, 2 kg of electrolyte, 3 kg of solubilizer, and 2 kg of softener are added to 110 kg of deionized water, and stirred and mixed evenly at 30°C to obtain a pretreatment solution; the knitted fabric is immersed in the pretreatment solution, soaked at 30°C for 20 minutes, and then washed to obtain a pretreated knitted fabric; wherein the surfactant is fatty alcohol polyoxyethylene ether; the electrolyte is a mixture of sodium chloride and sodium sulfate, and the weight ratio of sodium chloride to sodium sulfate is 2:1; the solubilizer is propylene glycol; the softener is sodium dodecylbenzene sulfonate; and the remaining steps are consistent with Example 1.

[0028] Example 4 The difference between Example 4 and Example 2 is that, pretreatment: 3 kg of surfactant, 1.2 kg of electrolyte, 1.7 kg of solubilizer, and 1.2 kg of softener are added to 100 kg of deionized water, and stirred and mixed evenly at 40°C to obtain a pretreatment solution; the knitted fabric is immersed in the pretreatment solution, soaked at 40°C for 20 minutes, and then washed to obtain a pretreated knitted fabric; wherein the surfactant is fatty alcohol polyoxyethylene ether; the electrolyte is a mixture of sodium chloride and sodium sulfate, and the weight ratio of sodium chloride to sodium sulfate is 2:1; the solubilizer is propylene glycol; the softener is sodium dodecylbenzene sulfonate; and the remaining steps are consistent with Example 1.

[0029] Example 5 The difference between Example 5 and Example 2 is that, pretreatment: 3 kg of surfactant, 1.2 kg of electrolyte, 1.7 kg of solubilizer, and 1.2 kg of softener are added to 100 kg of deionized water, and stirred and mixed evenly at 50°C to obtain a pretreatment solution; the knitted fabric is immersed in the pretreatment solution, soaked at 50°C for 20 minutes, and then washed to obtain a pretreated knitted fabric; wherein the surfactant is fatty alcohol polyoxyethylene ether; the electrolyte is a mixture of sodium chloride and sodium sulfate, and the weight ratio of sodium chloride to sodium sulfate is 2:1; the solubilizer is propylene glycol; the softener is sodium dodecylbenzene sulfonate; and the remaining steps are consistent with Example 1.

[0030] Example 6 The difference between Example 6 and Example 4 is that, dyeing: 25 kg of reactive dye, 15 kg of penetrant, 10 kg of regulator, 15 kg of anti-dyeing salt, and 0.5 kg of buffer are stirred and mixed uniformly to obtain a dye, and then the dye is added to deionized water, stirred and mixed uniformly at 20°C to obtain a dye solution; wherein the concentration of the dye in the dye solution is 10 g / L; wherein the penetrant is a mixture of polyoxyethylene fatty alcohol ether and alkylphenol polyoxyethylene ether, and the weight ratio of polyoxyethylene fatty alcohol ether and alkylphenol polyoxyethylene ether is 1:1; the regulator is sodium bicarbonate; the anti-dyeing salt is sodium nitrate; the buffer is disodium hydrogen phosphate; and the remaining steps are consistent with Example 4.

[0031] Example 7 The difference between Example 7 and Example 4 is that, dyeing: 30 kg of reactive dye, 20 kg of penetrant, 15 kg of regulator, 20 kg of anti-dyeing salt and 1 kg of buffer are stirred and mixed to obtain dye, and then the dye is added to deionized water, stirred and mixed at 20°C to obtain dye solution; wherein the concentration of the dye in the dye solution is 10 g / L; wherein the penetrant is a mixture of polyoxyethylene fatty alcohol ether and alkylphenol polyoxyethylene ether, and the weight ratio of polyoxyethylene fatty alcohol ether and alkylphenol polyoxyethylene ether is 1:1; the regulator is sodium bicarbonate; the anti-dyeing salt is sodium nitrate; the buffer is disodium hydrogen phosphate; and the remaining steps are consistent with Example 4.

[0032] Example 8 The difference between Example 8 and Example 6 is that, dyeing: 25 kg of active dye, 15 kg of penetrant, 10 kg of regulator, 15 kg of resist salt, and 0.5 kg of buffer are stirred and mixed to obtain dye, and then the dye is added to deionized water, stirred and mixed at 20°C to obtain dye solution; wherein the concentration of the dye in the dye solution is 10 g / L; wherein the penetrant is a mixture of polyoxyethylene fatty alcohol ether and alkylphenol polyoxyethylene ether, and the weight ratio of polyoxyethylene fatty alcohol ether to alkylphenol polyoxyethylene ether is 1:1; the regulator is sodium bicarbonate; the resist salt is sodium nitrate; and the buffer is disodium hydrogen phosphate; The pretreated knitted fabric was placed in the dye solution, immersed at 25° C. for 20 min, taken out, washed with water, and heat-set to obtain a dyed knitted fabric; the remaining steps were consistent with Example 6.

[0033] Example 9 The difference between Example 9 and Example 6 is that, dyeing: 25 kg of active dye, 15 kg of penetrant, 10 kg of regulator, 15 kg of resist salt, and 0.5 kg of buffer are stirred and mixed to obtain dye, and then the dye is added to deionized water, stirred and mixed at 20°C to obtain dye solution; wherein the concentration of the dye in the dye solution is 10 g / L; wherein the penetrant is a mixture of polyoxyethylene fatty alcohol ether and alkylphenol polyoxyethylene ether, and the weight ratio of polyoxyethylene fatty alcohol ether to alkylphenol polyoxyethylene ether is 1:1; the regulator is sodium bicarbonate; the resist salt is sodium nitrate; and the buffer is disodium hydrogen phosphate; The pretreated knitted fabric was placed in the dye solution, immersed at 30° C. for 10 min, taken out, washed with water, and heat-set to obtain a dyed knitted fabric; the remaining steps were consistent with Example 6.

[0034] Example 10 The difference between Example 10 and Example 8 is that, pretreatment: 3kg of surfactant, 1.2kg of electrolyte, 1.7kg of solubilizer, and 1.2kg of softener are added to 100kg of deionized water, stirred and mixed at 30°C, then disodium hydrogen phosphate is added, and the pH of the mixed solution is adjusted to 5.5 to obtain a pretreatment solution; the knitted fabric is immersed in the pretreatment solution, soaked at 30°C for 20 minutes, and then washed to obtain a pretreated knitted fabric; wherein the surfactant is fatty alcohol polyoxyethylene ether; the electrolyte is a mixture of sodium chloride and sodium sulfate, and the weight ratio of sodium chloride to sodium sulfate is 2:1; the solubilizer is propylene glycol; the softener is sodium dodecylbenzene sulfonate; and the remaining steps are consistent with Example 8.

[0035] Embodiment 11 The difference between Example 11 and Example 10 is that the electrolyte is sodium chloride; the remaining steps are consistent with Example 10.

[0036] Example 12 The difference between Example 12 and Example 10 is that the electrolyte is sodium sulfate; the remaining steps are consistent with Example 10.

[0037] Example 13 The difference between Example 13 and Example 10 is that the penetrant is polyoxyethylene fatty alcohol ether; the remaining steps are consistent with Example 10.

[0038] Embodiment 14 The difference between Example 14 and Example 10 is that the penetrant is alkylphenol polyoxyethylene ether; the remaining steps are consistent with Example 10.

[0039] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that, pretreatment: 1 kg of surfactant is added to 90 kg of deionized water, stirred and mixed evenly at 30°C to obtain a pretreatment liquid; the knitted fabric is immersed in the pretreatment liquid, soaked at 30°C for 20 minutes, and then washed to obtain a pretreated knitted fabric; wherein the surfactant is fatty alcohol polyoxyethylene ether; the remaining steps are consistent with Example 1.

[0040] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that, in dyeing, 20 kg of active dye is added to deionized water, and stirred and mixed evenly at 20° C. to obtain a dye solution; wherein the concentration of the active dye in the dye solution is 10 g / L; and the remaining steps are consistent with Example 1.

[0041] Performance test Dyeing effect: Testing the blueness b of the knitted fabrics dyed in each embodiment and comparative example * , and dry and wet rubbing color fastness, b* The larger the value, the darker the yellow of the knitted fabric.

[0042] Table 1 Performance test results of knitted fabrics sample <![CDATA[b * ]]> Dry rubbing fastness Wet rubbing fastness Example 1 62.68 5 5 Example 2 62.79 5 5 Example 3 62.45 5 5 Example 4 63.78 5 5 Example 5 63.01 5 5 Example 6 65.89 5 5 Example 7 65.92 5 5 Example 8 67.78 5 5 Example 9 67.00 5 5 Example 10 69.79 5 5 Embodiment 11 65.23 4-5 4-5 Example 12 65.02 4-5 4-5 Example 13 67.15 5 5 Embodiment 14 67.03 5 5 Comparative Example 1 53.26 4 4 Comparative Example 2 52.15 4 4 Combining Example 1 and Comparative Examples 1-2, the dyeing effect of the knitted fabric in Example 1 is better. It can be seen that using the dyeing method in the present application, the knitted fabric is first pretreated with a composite pretreatment liquid composed of deionized water, a surfactant, an electrolyte, a solubilizer, and a softener, and then dyed with a composite dye composed of an active dye, a penetrant, a regulator, a dye-resistant salt, and a buffer, which improves the dyeing effect of the knitted fabric, and the pretreatment and dyeing are both carried out at low temperatures, which is energy-saving and environmentally friendly.

[0043] In combination with Examples 1-3, the dyeing effects of the knitted fabrics in Examples 1-3 are all good, which shows that when the pretreatment liquid is prepared, the pretreatment liquid in Examples 1-3 has a good pretreatment effect on the knitted fabric.

[0044] Combining Example 2, Example 4 and Example 5, the dyeing effect of the knitted fabric in Example 4 is the best. It can be seen that when preparing the pretreatment liquid, the pretreatment temperature in Example 4 is the best, so that the final dyeing effect of the knitted fabric is the best.

[0045] Combining Example 4, Example 6 and Example 7, it can be seen that when preparing dyes, the dyes in Example 4, Example 6 and Example 7 all have good dyeing effects on knitted fabrics.

[0046] Combining Example 6, Example 8 and Example 9, the dyeing effect of the knitted fabric in Example 8 is the best. It can be seen that when dyeing the knitted fabric, the dyeing conditions in Example 8 are the best, so the dyeing effect of the knitted fabric is better.

[0047] Combining Example 8 and Example 10, the dyeing effect of the knitted fabric in Example 10 is better. It can be seen that when preparing the pretreatment liquid, adding disodium hydrogen phosphate and adjusting the pH of the pretreatment liquid to 5.5 can further enhance the binding force between the dye and the fabric, thereby further improving the dyeing effect.

[0048] Combining Example 10, Example 11 and Example 12, the dyeing effect of the knitted fabric in Example 10 is the best. It can be seen that when preparing the pretreatment solution, the electrolyte is preferably a mixture of sodium chloride and sodium sulfate, and the treatment effect of the obtained pretreatment solution is better.

[0049] Combining Example 10, Example 13 and Example 14, the dyeing effect of the knitted fabric in Example 10 is the best. It can be seen that when preparing the dye, the penetrant is preferably a mixture of polyoxyethylene fatty alcohol ether and alkylphenol polyoxyethylene ether, and the dyeing effect of the dye is better.

[0050] 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 knitted fabric energy-saving dyeing method, characterized in that: The following steps are involved: Pretreatment: immersing the knitted fabric in a pretreatment solution at 30-50°C, and then washing to obtain a pretreated knitted fabric; wherein the raw materials of the pretreatment solution include the following components in parts by weight: 90-110 parts of deionized water, 1-5 parts of a surfactant, 0.5-2 parts of an electrolyte, 0.5-3 parts of a solubilizer, and 0.5-2 parts of a softener; Dyeing: putting the pretreated knitted fabric into the dye solution, soaking it at 20-30°C, taking it out, washing it with water, and heat-setting it to obtain a dyed knitted fabric; wherein the raw materials of the dye in the dye solution include the following components in parts by weight: 20-30 parts of active dyes, 10-20 parts of penetrants, 5-15 parts of regulators, 10-20 parts of resist salts, and 0.1-1 parts of buffers.

2. The energy-saving dyeing method for knitted fabrics according to claim 1, characterized in that: The surfactant comprises one or a mixture of alkyl glycoside and fatty alcohol polyoxyethylene ether.

3. The energy-saving dyeing method for knitted fabrics according to claim 1, characterized in that: The electrolyte comprises a mixture of sodium chloride and sodium sulfate.

4. The energy-saving dyeing method for knitted fabrics according to claim 1, characterized in that: The solubilizer includes ethylene glycol, propylene glycol or a mixture of the two.

5. The energy-saving dyeing method for knitted fabrics according to claim 1, characterized in that: The softener includes sodium dodecylbenzene sulfonate.

6. The energy-saving dyeing method for knitted fabrics according to claim 1, characterized in that: The raw materials of the pretreatment liquid also include disodium hydrogen phosphate, so that the pH value of the pretreatment liquid is 5.

5.

7. The energy-saving dyeing method for knitted fabrics according to claim 1, characterized in that: The penetrant comprises a mixture of polyoxyethylene fatty alcohol ether and alkylphenol polyoxyethylene ether.

8. The energy-saving dyeing method for knitted fabrics according to claim 1, characterized in that: The dye-resisting salt includes one of sodium nitrate and ammonium phosphate or a mixture of the two.

9. The energy-saving dyeing method for knitted fabrics according to claim 1, characterized in that: The buffer comprises one of disodium hydrogen phosphate and potassium dihydrogen phosphate or a mixture of the two.

10. The energy-saving dyeing method for knitted fabrics according to claim 1, characterized in that: In the dyeing step, the pretreated knitted fabric is placed in the dye solution and immersed at 20-30° C. for 10-30 minutes.