A dyeing method for improving the dyeing performance of polyester fiber

Abstract

The present invention belongs to the technical field of polyester fiber dyeing, and specifically relates to a dyeing method for improving the dyeing performance of polyester fibers. The method of the present invention comprises: preparation of a pretreatment solution, fiber pretreatment, fiber dyeing, and fiber fixation reduction. The dyeing method of the present invention can significantly improve the dyeing performance of polyester fibers, wherein the performance includes the dye uptake rate, color fixation rate, color fastness, and rubbing fastness of the fibers; the process steps of the present invention are relatively simple, and the dyeing effect is excellent. At the same time, the raw materials used are green and environmentally friendly, reducing the harm to the environment, conforming to the concept of green chemistry and sustainable development, and suitable for large-scale industrial production. The present invention compares the mechanical strength of polyester fibers after dyeing with that before dyeing, and finds that the mechanical strength of polyester fibers after dyeing is not much different from that before dyeing, which greatly improves the practicality of the fibers and lays a foundation for promoting the wide application of polyester fiber fabrics in the field of daily use.

Description

Technical Field

[0001] The invention belongs to the technical field of polyester fiber dyeing, and particularly relates to a dyeing method for improving the dyeing performance of polyester fiber. Background Art

[0002] Polyester fiber, commonly known as polyester, is a polyester material synthesized by polycondensation of diols and dibasic acids. After spinning, synthetic fibers are obtained, referred to as PET fibers. Polyester fiber was invented in 1941 and was the largest synthetic fiber variety at the time. The advantages of polyester fiber are good shape retention and wrinkle resistance, high elastic recovery ability and strength, and it is non-linting, wrinkle-resistant, iron-free, and durable. In recent years, the polyester fiber industry has developed rapidly worldwide and has always maintained a relatively fast growth rate.

[0003] Polyester fiber has high strength, high modulus and low water absorption. It has a wide range of uses as both civil and industrial fabrics. As a textile material, polyester staple fiber can be spun in pure form or blended with other fibers. It can be blended with natural fibers such as cotton, linen, and wool, or with other chemical staple fibers such as viscose, acetate, and polyacrylonitrile. The imitation cotton, wool, and linen fabrics made from pure or blended polyester staple fibers generally have the original excellent properties of polyester fibers, such as wrinkle resistance, pleat retention, dimensional stability, wear resistance, and washability.

[0004] A big disadvantage of polyester fiber is that it is difficult to dye. Under normal conditions, it is difficult to dye into a medium-dark color and the color is single. Therefore, finding a method suitable for dyeing polyester fiber will greatly improve its application value. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a dyeing method for improving the dyeing performance of polyester fibers, by pre-treating the surface of polyester fibers, modifying the fiber surface, and forming a good dyeing surface; by applying pressure, using disperse dyes for dyeing, and matching appropriate dyeing parameters, the organic molecules of the disperse dyes are fixed on the surface of the fiber material and its surface carboxyl groups and other active groups, thereby improving the fiber's dyeing rate, color fixation rate, friction and color fastness. The technical problem to be solved is to provide an excellent polyester fiber pretreatment process and dyeing process to overcome the shortcomings of low dyeing rate and low color fastness during the polyester fiber dyeing process.

[0006] The technical solution of the present invention is as follows:

[0007] A dyeing method for improving the dyeing performance of polyester fiber comprises the following steps:

[0008] (1) Preparation of pretreatment solution: uniformly mix detergent and deionized water to obtain a pretreatment solution;

[0009] (2) Fiber pretreatment: immersing the polyester fiber in a pretreatment solution, heating and then keeping the temperature, and then cooling to room temperature, taking out the polyester fiber, washing it with deionized water, and drying it to obtain the pretreated polyester fiber;

[0010] (3) Fiber dyeing: immersing the pretreated polyester fiber in a dye solution, then placing the dye solution in a reactor, heating the dye solution under pressure, keeping the temperature, cooling and reducing the pressure, taking out the fiber, washing it with water, and drying it to obtain a dyed polyester fiber;

[0011] (4) Fiber color fixation reduction: The dyed polyester fiber is put into the color fixation solution for color fixation treatment, and then the fiber is washed with water, acid washed, washed with water, and dried in sequence.

[0012] The drying mentioned in the present invention refers to all methods that can dry materials or products, such as baking or air-drying, but is not limited to the above drying methods.

[0013] Preferably, in (1), the detergent is at least one of degreasing agent, washing powder, detergent or cleaning agent.

[0014] Preferably, in (2), the fiber pretreatment step is: immersing the polyester fiber in a pretreatment solution, heating it to 60-100°C, keeping it warm for 20-90 minutes, then cooling it to room temperature, taking out the polyester fiber, washing it with deionized water, and drying it to obtain the pretreated polyester fiber.

[0015] Preferably, in (3), the pretreated polyester fiber is immersed in a dye solution at a bath ratio of 10 to 20:1, and then the dye solution is placed in a reactor; the reactor is pressed to 1.0 to 2.0 MPa, the dye solution is heated to 50 to 130°C, kept warm for 20 to 120 minutes, the dye solution is cooled to 20 to 25°C and the pressure is reduced, the fiber is taken out, washed with water, and dried to obtain a dyed polyester fiber;

[0016] The dye solution comprises disperse dye, buffer solution, swelling agent, dye dispersant and dye leveling agent;

[0017] In the dye liquor, the amount of disperse dye added is 1.0% to 7.0% (owf); the amount of expander added is 0.1 to 3.0% (owf); the amount of leveling agent added is 0.1 to 2.0% (owf); the amount of dispersant added is 0.1 to 2.0% (owf); and the pH value of the dye liquor is 3.0 to 5.0.

[0018] Preferably, in (3), the disperse dye in the dye solution is a cationic dye;

[0019] The leveling agent is at least one of alkylphenol polyoxyethylene ether, ethylene glycol monomethyl ether, and β-dimethylaminoethyl stearamide;

[0020] The dispersant is at least one of fatty alcohol polyoxyethylene ether, polyvinyl pyrrolidone, sodium methylene dinaphthalene sulfonate, polyethylene glycol and sodium dodecyl sulfonate;

[0021] The expansion agent is at least one of ethylene glycol phenyl ether, phenoxyisopropyl alcohol, phenol, anisole, triethylamine, N,N-dimethylformamide, benzyl alcohol and thiophene.

[0022] Preferably, in (4), the color fixing solution comprises a reducing agent and an alkaline substance; the color fixing solution comprises 0.1 to 2.0% (owf) of the color fixing agent, and the pH of the color fixing solution is 7.0 to 9.0;

[0023] The reducing agent is at least one of sodium hydrosulfite and sodium bisulfite;

[0024] The alkaline substance is at least one of sodium hydroxide, sodium carbonate, sodium bicarbonate and potassium hydroxide.

[0025] Preferably, the above-mentioned dyeing method for improving the dyeing performance of polyester fiber comprises the following steps:

[0026] (1) Preparation of pretreatment solution: take detergent and deionized water, mix them evenly in a volume weight ratio of deionized water to detergent of 10 to 20:1 to prepare a pretreatment solution;

[0027] (2) Fiber pretreatment: immerse the polyester fiber in a pretreatment solution, heat it to 60-100°C, keep it warm for 20-90 minutes, then cool it to room temperature, take out the polyester fiber, wash it with deionized water, and dry it to obtain the pretreated polyester fiber;

[0028] (3) Fiber dyeing: The pretreated polyester fiber is immersed in the dye solution at a bath ratio of 10 to 20:1, and then the dye solution is placed in a reactor; the reactor is pressed to 1.0 to 2.0 MPa, the dye solution is heated to 50 to 130°C, and kept warm for 20 to 120 minutes, the dye solution is cooled to 20 to 25°C and then the pressure is reduced, the fiber is taken out, washed with water, and dried to obtain the dyed polyester fiber;

[0029] The dye solution comprises disperse dye, buffer solution, swelling agent, dye dispersant and dye leveling agent; the buffer solution is acetic acid-sodium acetate solution with a pH of 3 to 3.5; the amount of the buffer solution is such that the pH of the dye solution is between 3.0 and 5.0;

[0030] In the dyeing solution, the amount of disperse dye added is 1.0% to 7.0% (owf); the amount of swelling agent added is 0.1 to 3.0% (owf); the amount of leveling agent added is 0.1 to 2.0% (owf); the amount of dispersant added is 0.1 to 2.0% (owf); the pH of the dyeing solution is 3.0 to 5.0;

[0031] The disperse dyes in the dye solution are cationic dyes;

[0032] The leveling agent is at least one of alkylphenol polyoxyethylene ether, ethylene glycol monomethyl ether, and β-dimethylaminoethyl stearamide;

[0033] The dispersant is at least one of fatty alcohol polyoxyethylene ether, polyvinyl pyrrolidone, sodium methylene dinaphthalene sulfonate, polyethylene glycol and sodium dodecyl sulfonate;

[0034] The swelling agent is at least one of ethylene glycol phenyl ether, phenoxyisopropyl alcohol, phenol, anisole, triethylamine, N,N-dimethylformamide, benzyl alcohol and thiophene;

[0035] (4) Fiber fixation reduction: The dyed polyester fiber is placed in a fixation solution at a bath ratio of 10 to 20:1, the pH is adjusted to 7 to 10, the fixation temperature is 40 to 90°C, and the fixation treatment is performed for 5 to 30 minutes. After the fixation treatment, the fiber is washed with water, acid washed, washed with water, and dried in sequence;

[0036] The color fixing solution includes a reducing agent and an alkaline substance; the color fixing solution contains 0.1 to 2.0% (owf) of the color fixing agent, and the pH value of the color fixing solution is 7.0 to 9.0; the reducing agent is at least one of sodium hydrosulfite and sodium bisulfite;

[0037] The alkaline substance is at least one of sodium hydroxide, sodium carbonate, sodium bicarbonate and potassium hydroxide.

[0038] Preferably, in (4), the fixing temperature is 50 to 70° C., and the fixing treatment is performed for 10 to 20 minutes.

[0039] After the polyester fiber in the present invention is treated with disperse dyes and a novel chemical pretreatment process, the dye molecules can fully absorb and dye on the surface of the polyester fiber, and can combine with the carboxyl groups on the surface after the chemical pretreatment, achieving good dyeing and color fixing effects; and under the synergistic effect of the leveling agent, dispersant, and swelling agent, uniform dyeing and color fixing are achieved. Crucially, the present invention uses a special swelling agent to better transfer the dye to the inside of the polyester fiber, thereby achieving a good leveling effect. After a good process, the fiber dyeing rate, color fastness, friction fastness, etc. can be significantly improved.

[0040] The beneficial effects of the present invention are:

[0041] (1) The treatment process involved in the present invention is simple to operate, has low requirements on equipment and steps, and the main pretreatment liquid does not involve highly volatile and highly toxic substances, can be easily treated, does not generate excessive waste liquid, is pollution-free, and is conducive to large-scale industrial production;

[0042] (2) Compared with traditional dyeing methods such as reactive dyes and complex dyes, this process does not contain heavy metals and does not require the addition of high concentrations of acid or alkali. It can dye efficiently, which reduces costs and avoids environmental problems during the dyeing process.

[0043] (3) Compared with the traditional dyeing method, the use of detergent for pretreatment reduces wastewater discharge, reduces environmental pollution, and conforms to the concept of sustainable development;

[0044] (4) By optimizing the dyeing process, dyeing parameters such as dyeing time, dye solution temperature, dye solution concentration, and dye solution pH value are optimized to improve the fiber dye uptake rate and fully consider the fiber dye uptake limit so that the dyeing can achieve the full dyeing effect;

[0045] (5) Based on the improvement of the most basic dye uptake rate of polyester fiber, the present invention increases the fiber spacing of polyester fiber by adding a swelling agent, improves the dye migration rate, and further enhances the color fastness of the fiber, which can promote the widespread production and application of polyester fiber textiles;

[0046] (6) While improving the fiber dyeing rate and other indicators, the mechanical strength of the fiber does not change significantly compared with before dyeing, and a good mechanical strength is maintained, laying a foundation for promoting the widespread application of polyester fiber fabrics in daily use fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a process flow chart of the present invention;

[0048] Figure 2 This is a picture of the polyester fiber dyeing process in Example 1 (red);

[0049] Figure 3 This is a photo of the polyester fiber after dyeing in Example 1 (red);

[0050] Figure 4 The dyeing and bleaching pictures (red) are processed by the dyeing method without adding bulking agent;

[0051] Figure 5 This is a product picture of the polyester fiber before the reduction of the polyester fiber dyeing in Example 2 (yellow);

[0052] Figure 6 This is a photo of the polyester fiber after dyeing in Example 2. Under the condition of maintaining the dyeing temperature at 95-100°C, the color of the fiber treated with the bulking agent is deeper and more uniform. DETAILED DESCRIPTION

[0053] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in conjunction with specific implementation methods.

[0054] Example 1

[0055] A dyeing method for improving the dyeing performance of polyester fiber, the specific steps are:

[0056] (1) Preparation of pretreatment solution: Take 4g of detergent (washing powder) and deionized water, mix them evenly in a volume-to-weight ratio of deionized water to detergent of 15:1 to prepare a pretreatment solution;

[0057] (2) Fiber pretreatment: 10.0 g of polyester fiber was immersed in 100.0 g of pretreatment solution at a bath ratio of 10:1, heated to 100 °C, and the solution was kept warm for 20 min, then cooled to room temperature, the fiber was taken out and rinsed with deionized water and dried;

[0058] (3) Fiber dyeing: The pretreated polyester fiber is put into 100.0 g of dye solution according to a bath ratio of 10:1, wherein the dye solution contains 5.0 g of disperse red dye, 1.1 g of anisole swelling agent, 1.0 g of ethylene glycol monomethyl ether leveling agent and 1.0 g of sodium dodecyl sulfonate dispersant; an acetic acid-sodium acetate buffer solution with a pH of about 3 is added to adjust the pH of the dye solution to about 4.0; the pressure is adjusted to 2.0 MPa, the temperature is raised to 100°C, kept warm for 30 minutes, and then cooled to room temperature, the fiber is taken out and then washed, dried or air-dried;

[0059] (4) Fiber color fixation reduction: The dyed polyester fiber is placed into 100.0 g of color fixation solution at a bath ratio of 10:1, the pH value is controlled at 8.0, the temperature is raised to 80°C, and the temperature is kept for 10 minutes. Then the fiber is rinsed with warm water, acid washed, washed with water, and dried.

[0060] After dyeing using the method used in this embodiment, the soap fastness of the polyester fiber is level 5, and the K / S value is 9.807.

[0061] Example 2

[0062] A dyeing method for improving the dyeing performance of polyester fiber, the specific steps are:

[0063] (1) Preparation of pretreatment solution: Take 4g of detergent (detergent) and deionized water, mix them evenly in a volume-to-weight ratio of 12:1 to prepare a pretreatment solution;

[0064] (2) Fiber pretreatment: 10.0 g of polyester fiber was immersed in 100.0 g of pretreatment solution at a bath ratio of 10:1, heated to 100 °C, and the solution was kept warm for 20 min, then cooled to room temperature, the fiber was taken out and rinsed with deionized water and dried;

[0065] (3) Fiber dyeing: The pretreated polyester fiber was put into 100 g of dye solution according to a bath ratio of 10:1, wherein the dye solution contained 5.0 g of disperse yellow dye, 1.7 g of anisole swelling agent, 1.0 g of ethylene glycol monomethyl ether leveling agent and 1.0 g of sodium dodecyl sulfonate dispersant; an acetic acid-sodium acetate buffer solution with a pH of about 3 was added to adjust the pH of the dye solution to about 3.5; the pressure was adjusted to 2.0 MPa, the temperature was raised to 100 °C, kept warm for 30 min, and then cooled to room temperature, the fiber was taken out and washed and dried;

[0066] (4) Fiber color fixation reduction: The dyed polyester fiber is placed into 100.0 g of color fixation solution at a bath ratio of 10:1, the pH value is controlled at 8.0, the temperature is raised to 80°C, and the temperature is kept for 10 minutes. Then the fiber is rinsed with warm water, acid washed, washed with water, and dried.

[0067] After dyeing using the method used in this embodiment, the soap fastness of the polyester fiber is level 5, and the K / S value is 9.677.

[0068] Example 3

[0069] A dyeing method for improving the dyeing performance of polyester fiber, the specific steps are:

[0070] (1) Preparation of pretreatment solution: Take 4g of detergent (washing powder) and deionized water, mix them evenly in a volume-to-weight ratio of deionized water to detergent of 18:1 to prepare a pretreatment solution;

[0071] (2) Fiber pretreatment: 10.0 g of polyester fiber was immersed in 100.0 g of pretreatment solution at a bath ratio of 10:1, heated to 100 °C, and the solution was kept warm for 20 min, then cooled to room temperature, the fiber was taken out and rinsed with deionized water and dried;

[0072] (3) Fiber dyeing: The pretreated polyester fiber is put into 100.0g dye solution at a bath ratio of 10:1 for dyeing, wherein the dye solution contains 5.0g disperse red dye, 1.1g anisole swelling agent, 1.0g ethylene glycol monomethyl ether leveling agent and 1.0g sodium dodecyl sulfonate dispersant; an acetic acid-sodium acetate buffer solution with a pH of about 3 is added to adjust the pH of the dye solution to about 5.0; the pressure is adjusted to 1.5MPa, the temperature is raised to 100℃, kept warm for 30min, then cooled to room temperature, the fiber is taken out and washed and dried; (4) Fiber color fixation reduction: The dyed polyester fiber is put into 100.0g color fixation solution at a bath ratio of 10:1, the pH is controlled to 8, the temperature is raised to 80℃, kept warm for 10min, and then the fiber is rinsed with warm water, acid washed, washed and dried.

[0073] After dyeing using the method used in this embodiment, the soap fastness of the polyester fiber is level 5, and the K / S value is 9.507.

[0074] Example 4

[0075] A dyeing method for improving the dyeing performance of polyester fiber, the specific steps are as follows:

[0076] (1) Preparation of pretreatment solution: Take 4g of detergent (washing powder) and deionized water, mix them evenly in a volume-to-weight ratio of deionized water to detergent of 20:1 to prepare a pretreatment solution;

[0077] (2) Fiber pretreatment: 10.0 g of polyester fiber was immersed in 100.0 g of pretreatment solution at a bath ratio of 10:1, heated to 100 °C, and the solution was kept warm for 20 min, then cooled to room temperature, the fiber was taken out and rinsed with deionized water and dried;

[0078] (3) Fiber dyeing: The pretreated polyester fiber was dyed in 100.0 g of dye solution at a bath ratio of 10:1, wherein the dye solution contained 5.0 g of disperse red dye, 1.1 g of anisole swelling agent, 1.0 g of ethylene glycol monomethyl ether leveling agent and 1.0 g of polyethylene glycol dispersant; an acetic acid-sodium acetate buffer solution with a pH of about 3 was added to adjust the pH of the dye solution to about 4.0; the pressure was adjusted to 2.0 MPa, the temperature was raised to 105°C, kept warm for 30 min, and then cooled to room temperature, the fiber was taken out and then washed and dried;

[0079] (4) Fiber color fixation reduction: The dyed polyester fiber is placed into 100.0 g of color fixation solution at a bath ratio of 10:1, the pH value is controlled at 8.0, the temperature is raised to 80°C, and the temperature is kept for 10 minutes. Then the fiber is rinsed with warm water, acid washed, washed with water, and dried.

[0080] After dyeing using the method used in this embodiment, the soap fastness of the polyester fiber is level 5, and the K / S value is 9.406.

[0081] Example 5

[0082] A dyeing method for improving the dyeing performance of polyester fiber, the specific steps are:

[0083] (1) Preparation of pretreatment solution: Take 4g of detergent (washing powder) and deionized water, mix them evenly in a volume-to-weight ratio of deionized water to detergent of 15:1 to prepare a pretreatment solution;

[0084] (2) Fiber pretreatment: 10.0 g of polyester fiber was immersed in 100.0 g of pretreatment solution at a bath ratio of 10:1, heated to 100 °C, and the solution was kept warm for 20 min, then cooled to room temperature, the fiber was taken out and rinsed with deionized water and dried;

[0085] (3) Fiber dyeing: The pretreated polyester fiber was dyed in 100.0 g of dye solution at a bath ratio of 10:1, wherein the dye solution contained 5.0 g of disperse red dye, 1.1 g of phenoxyisopropyl alcohol swelling agent, 1.0 g of ethylene glycol monomethyl ether leveling agent and 1.0 g of polyethylene glycol dispersant; an acetic acid-sodium acetate buffer solution with a pH of about 3 was added to adjust the pH of the dye solution to about 4.5; the pressure was adjusted to 2.0 MPa, the temperature was raised to 110°C, kept warm for 30 min, and then cooled to room temperature, the fiber was taken out and then washed and dried;

[0086] (4) Fiber color fixation reduction: The dyed polyester fiber is placed into 100.0 g of color fixation solution at a bath ratio of 10:1, the pH value is controlled at 8.0, the temperature is raised to 80°C, and the temperature is kept for 10 minutes. Then the fiber is rinsed with warm water, acid washed, washed with water, and dried.

[0087] After dyeing using the method used in this embodiment, the soap fastness of the polyester fiber is level 5, and the K / S value is 9.273.

[0088] Comparative Example 1

[0089] The biggest difference from Example 1 is that (3) during the fiber dyeing process, dyeing is carried out under normal pressure;

[0090] A dyeing method for improving the dyeing performance of polyester fiber, the specific steps are:

[0091] (1) Preparation of pretreatment solution: Take 4g of detergent (washing powder) and deionized water, mix them evenly in a volume-to-weight ratio of deionized water to detergent of 15:1 to prepare a pretreatment solution;

[0092] (2) Fiber pretreatment: 10.0 g of polyester fiber was immersed in 100.0 g of pretreatment solution at a bath ratio of 10:1, heated to 100 °C, and the solution was kept warm for 20 min, then cooled to room temperature, the fiber was taken out and rinsed with deionized water and dried;

[0093] (3) Fiber dyeing: The pretreated polyester fiber is put into 100.0 g of dye solution according to a bath ratio of 10:1, wherein the dye solution contains 5.0 g of disperse red dye, 1.1 g of anisole swelling agent, 1.0 g of ethylene glycol monomethyl ether leveling agent and 1.0 g of sodium dodecyl sulfonate dispersant; an acetic acid-sodium acetate buffer solution with a pH of about 3 is added to adjust the pH of the dye solution to about 4.5; the pressure is adjusted to normal pressure, the temperature is raised to 100°C, kept warm for 30 minutes, and then cooled to room temperature, the fiber is taken out and washed and dried;

[0094] (4) Fiber color fixation reduction: The dyed polyester fiber is placed into 100.0 g of color fixation solution at a bath ratio of 10:1, the pH value is controlled at 8.0, the temperature is raised to 80°C, and the temperature is kept for 10 minutes. Then the fiber is rinsed with warm water, acid washed, washed with water, and dried.

[0095] After dyeing using the method used in this embodiment, the soap fastness of the polyester fiber is level 4, and the K / S value is 8.556.

[0096] Comparative Example 2

[0097] A dyeing method for improving the dyeing performance of polyester fiber, the specific steps are:

[0098] (1) Preparation of pretreatment solution: Take 4g of detergent (washing powder) and deionized water, mix them evenly in a volume-to-weight ratio of deionized water to detergent of 15:1 to prepare a pretreatment solution;

[0099] (2) Fiber pretreatment: 10.0 g of polyester fiber was immersed in 100.0 g of pretreatment solution at a bath ratio of 10:1, heated to 100 °C, and the solution was kept warm for 20 min, then cooled to room temperature, the fiber was taken out and rinsed with deionized water and dried;

[0100] (3) Fiber dyeing: The pretreated polyester fiber is put into 100.0 g of dye solution according to a bath ratio of 10:1, wherein the dye solution contains 5.0 g of disperse red dye, 1.0 g of ethylene glycol monomethyl ether leveling agent and 1.0 g of sodium dodecyl sulfonate dispersant; an acetic acid-sodium acetate buffer solution with a pH of about 3 is added to adjust the pH of the dye solution to about 4.5; the pressure is adjusted to 2.0 MPa, the temperature is raised to 100 °C, kept at this temperature for 30 min, and then cooled to room temperature, the fiber is taken out and then washed and dried;

[0101] (4) Fiber color fixation reduction: The dyed polyester fiber is placed into 100.0 g of color fixation solution at a bath ratio of 10:1, the pH value is controlled at 8.0, the temperature is raised to 80°C, and the temperature is kept for 10 minutes. Then the fiber is rinsed with warm water, acid washed, washed with water, and dried.

[0102] After dyeing using the method used in this embodiment, the soap fastness of the polyester fiber is level 4, and the K / S value is 8.379.

[0103] The relationship between the parameters and the soap fastness K / S value in the selected examples is as follows:

[0104]

[0105] It can be seen from the above data that under a pressure of 2.0 MP, the soap fastness of the polyester fiber is higher and the K / S value is larger. From the comparison between Example 2 and Comparative Example 2, it can be seen that the swelling agent added in the present invention is the key to the dyeing performance of the polyester fiber, and non-polar compounds such as anisole are easy to post-process after washing, which improves the soap fastness after dyeing. In addition, as the dyeing temperature increases, the K / S value decreases, and the performance is most excellent at 100°C.

[0106] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A dyeing method for improving the dyeing performance of polyester fiber, comprising the following steps: (1) Preparation of pretreatment solution: 4 g of washing powder and deionized water are mixed evenly at a volume weight ratio of deionized water to detergent of 15:1 to prepare a pretreatment solution; (2) Fiber pretreatment: 10.0 g of the fiber was immersed in 100.0 g of pretreatment solution at a bath ratio of 10:1, heated to 100 °C, and the solution was kept warm for 20 min, then cooled to room temperature, the fiber was taken out and rinsed with deionized water and dried; (3) Fiber dyeing: The pretreated polyester fiber is put into 100.0 g of dye solution according to a bath ratio of 10:1, wherein the dye solution contains 5.0 g of disperse red dye, 1.1 g of anisole swelling agent, 1.0 g of ethylene glycol monomethyl ether leveling agent and 1.0 g of sodium dodecyl sulfonate dispersant; an acetic acid-sodium acetate buffer solution with a pH of 3 is added to adjust the pH of the dye solution to 4.0; the pressure is adjusted to 2.0 MPa, the temperature is raised to 100°C, kept warm for 30 minutes, and then cooled to room temperature, the fiber is taken out, washed with water, and dried or air-dried; (4) Fiber fixation reduction: The dyed polyester fiber is placed in 100.0 g of fixation solution at a bath ratio of 10:1, the pH is controlled at 8.0, the temperature is raised to 80°C, and the temperature is kept for 10 minutes. The fiber is then rinsed with warm water, acid washed, washed with water, and dried; The soap fastness of the polyester fiber dyed by the dyeing method is grade 5, and the K / S value is 9.807.

Images