Continuous dyeing method for fabric and dyed fabric obtained by continuous dyeing method

Abstract

The invention provides a continuous fabric dyeing method and a dyed fabric obtained thereof.The method comprises the steps that dye liquor is applied to the fabric; electromagnetic waves are used for pre-fixation of the fabric, so that the liquid carrying rate is reduced, it is guaranteed that the fabric is colored uniformly, and part of dye on the fabric is fixed; carrying out secondary color fixation on the fabric in a non-water environment; and neutralizing, post-processing and drying the fabric subjected to secondary color fixation to finish continuous dyeing of the fabric. According to the dyeing method provided by the invention, electromagnetic wave pre-fixation and secondary fixation in a non-water environment are combined, so that not only is a very high fixation rate obtained, but also the dyeing uniformity of the fabric is ensured. Meanwhile, the water consumption after fabric dyeing is greatly reduced, the dyeing time is greatly shortened, and dyeing can be completed within 10 minutes at the soonest. The dyed fabric obtained by the method is high in fixation rate, excellent in dyeing uniformity, uniform in color yield, natural in colored light and good in color fastness.

Description

Technical Field

[0001] The invention relates to a continuous fabric dyeing method and the obtained dyed fabric, belonging to the technical field of dyeing and finishing. Background Art

[0002] Statistics show that the textile industry discharges approximately 2 billion tons of wastewater annually, of which printing and dyeing wastewater accounts for 70.0%-80.0%. In traditional cellulose fiber dyeing, pretreatment and dyeing require the most water. High dye usage and low fixation rates result in high COD and high chroma in wastewater. Furthermore, the traditional water-bath dyeing process requires the addition of large amounts of electrolytes to promote dyeing, significantly increasing the difficulty of wastewater treatment. Therefore, the printing and dyeing industry urgently needs to develop new dyeing technologies that can both improve dye utilization and reduce environmental pollution.

[0003] In recent years, non-aqueous dyeing technology has garnered widespread attention due to its significant environmental advantages. Using non-aqueous dyeing media instead of water can avoid the hydrolysis of dyes typically encountered in waterbath dyeing, improving dye utilization, avoiding water waste, and reducing chemical use. However, current non-aqueous dyeing technologies are costly and time-consuming, offering limited energy savings compared to traditional dyeing.

[0004] High-frequency electromagnetic waves, such as microwaves, radio frequency, and infrared, can rapidly diffuse and fix dye molecules on fibers, typically completing the dyeing process in just 1-10 minutes. In addition to high energy conversion efficiency, electromagnetic waves provide very uniform heating, effectively improving the uniformity of fabric dyeing. Therefore, electromagnetic wave dyeing technology, with its rapid, energy-saving, and efficient characteristics, holds great promise for application in the dyeing field. However, compared to non-aqueous dyeing, dyeing fabrics using electromagnetic wave technology alone suffers from lower fixation rates and cannot achieve the desired wash-free effect.

[0005] Therefore, providing a novel continuous dyeing method for fabrics and the resulting dyed fabrics has become a technical problem that needs to be solved urgently in this field. Summary of the Invention

[0006] In order to solve the above-mentioned shortcomings and deficiencies, the object of the present invention is to provide a continuous fabric dyeing method and the resulting dyed fabric.

[0007] In order to achieve the above object, the present invention provides a continuous fabric dyeing method, wherein the continuous fabric dyeing method comprises:

[0008] Step (1): applying dye liquor to the fabric;

[0009] Step (2): using electromagnetic waves to pre-fix the fabric to reduce the liquid pick-up rate, ensure uniform coloring of the fabric, and fix part of the dye on the fabric;

[0010] Step (3): performing secondary color fixation on the fabric in a non-aqueous environment to further improve the fixation rate of the dye;

[0011] Step (4): neutralizing, post-treating and drying the fabric after secondary color fixation to complete the continuous dyeing of the fabric.

[0012] As a specific embodiment of the above-mentioned continuous fabric dyeing method of the present invention, in step (2), the electromagnetic waves include electromagnetic waves such as microwaves and / or radio frequencies.

[0013] As a specific embodiment of the above-mentioned continuous fabric dyeing method of the present invention, in step (2), the frequency of the electromagnetic wave is 10-3000 MHZ, and the power per unit area is 0.5-50 W / cm 2 The electromagnetic wave pre-fixing time is 0.5-20 minutes.

[0014] As a specific embodiment of the above-mentioned continuous dyeing method of the fabric of the present invention, in step (2), during the pre-fixation process, the power of the electromagnetic wave, that is, the power of the electromagnetic wave transmitter, changes from high to low along with the direction of movement of the fabric; wherein the high power range of the electromagnetic wave is 5-50W / cm 2 Under this power condition, the fabric is treated for 10-180s, and the low power range is greater than 0.5W / cm 2 And less than 5W / cm 2 , treat the fabric under this power condition for 1-10 minutes.

[0015] During the pre-fixation process, electromagnetic waves can increase the reaction constant between the dye and the fibers in the fabric and the hydrolysis constant of the dye. When treated with high-power electromagnetic waves, the reaction speed of the dye and the fibers is greatly increased, and the moisture on the fabric is also rapidly lost (the remaining moisture on the fabric after high-power electromagnetic wave treatment is <40%), which can reduce the probability of hydrolysis. Therefore, the continuous fabric dyeing method provided by the present invention first uses high-power electromagnetic waves for pre-fixation to obtain a good fixation rate; after most of the moisture is lost, low-power is used for pre-fixation. Low power can still promote dye fixation without causing overdrying of the fabric, saving energy and reducing the strength loss / safety risks of the fabric under high-power electromagnetic waves.

[0016] As a specific embodiment of the above-described continuous dyeing method of the present invention, in step (2), during the pre-fixation process, the liquid pick-up rate is reduced to 0-20%. In the present invention, the speed of reducing the liquid pick-up rate of the fabric can be controlled by adjusting the power of the electromagnetic wave. For example, in some embodiments of the present invention, the liquid pick-up rate of the fabric can be reduced from 100% to 0-20% within 4 minutes by adjusting the power of the electromagnetic wave.

[0017] In step (3) of the above-mentioned continuous fabric dyeing method of the present invention, during the secondary fixation process, the dye contained in the dye liquor and the fibers contained in the fabric undergo a fixation reaction in a non-aqueous environment to complete the fixation of the dye.

[0018] As a specific embodiment of the above-mentioned continuous fabric dyeing method of the present invention, wherein, in step (3), the non-aqueous environment is provided by a liquid non-aqueous medium or a gaseous non-aqueous medium, wherein the non-aqueous medium includes one or a combination of alkanes, halogenated aliphatic hydrocarbons, aromatic hydrocarbons, ketone solvents, silane solvents, ester solvents, liquid paraffin, ether solvents and supercritical carbon dioxide. In some embodiments of the present invention, the halogenated aliphatic hydrocarbons can be, for example, chlorinated hydrocarbons.

[0019] As a specific embodiment of the above-mentioned continuous fabric dyeing method of the present invention, in step (3), the temperature of the secondary fixation is 60-120° C. and the time is 5-120 minutes.

[0020] The continuous fabric dyeing method provided by the present invention adopts a combination of electromagnetic wave pre-fixation and secondary fixation in a non-aqueous environment, which can make the dye contained in the dye solution penetrate and react in the fibers contained in the fabric in a short time, and obtain good uniformity and high fixation rate and color fastness.

[0021] As a specific embodiment of the above-mentioned continuous fabric dyeing method of the present invention, in step (1), the dye solution includes a reactive dye, an inorganic base, a penetrant and a polar solvent.

[0022] As a specific embodiment of the above-mentioned continuous fabric dyeing method of the present invention, in step (1), the inorganic base includes one or a combination of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and sodium silicate.

[0023] As a specific embodiment of the above-mentioned continuous fabric dyeing method of the present invention, in step (1), the amount of the inorganic base used is 5-50 g / L based on the total volume of the dye liquor.

[0024] As a specific embodiment of the above-mentioned continuous fabric dyeing method of the present invention, wherein, in step (1), the polar solvent comprises one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, acetonitrile, ethanol, isopropyl alcohol, ionic liquid, alcohol ether solvent, ester solvent and water. In addition, the present invention does not make specific requirements on the specific substances of the reactive dye and penetrant contained in the dye liquor, and can be reasonably selected as needed. The present invention also does not make specific requirements on the amount of the reactive dye, penetrant and polar solvent contained in the dye liquor, and can also be reasonably adjusted as needed.

[0025] As a specific embodiment of the above-mentioned continuous fabric dyeing method of the present invention, in step (1), the application method includes one or a combination of spraying, padding and spraying.

[0026] As a specific embodiment of the above-mentioned continuous fabric dyeing method of the present invention, wherein, in step (1), the fabric comprises a fabric formed of cellulose fiber or its blended fibers. In some embodiments of the present invention, the fabric can be, for example, cotton fabric.

[0027] As a specific embodiment of the above-mentioned continuous fabric dyeing method of the present invention, in step (1), the form of the fabric includes grey cloth or semi-bleached cloth.

[0028] The neutralization, post-treatment and drying involved in step (4) of the above-mentioned continuous fabric dyeing method of the present invention are all conventional operations in the field, and the present invention does not make specific requirements on their specific operations and process parameters, etc., which can be reasonably selected and adjusted as needed, as long as the purpose of the present invention can be achieved.

[0029] On the other hand, the present invention also provides a dyed fabric obtained by the above-mentioned continuous fabric dyeing method.

[0030] Compared with the prior art, the beneficial technical effects achieved by the present invention include:

[0031] The fabric continuous dyeing method provided by the present invention combines electromagnetic wave dyeing technology (electromagnetic wave pre-fixation) and non-aqueous dyeing technology (secondary fixation under non-aqueous environment), utilizes the rapid and uniform characteristics of electromagnetic wave dyeing, the part of the dye on the fabric is evenly fixed on the fabric and reduces the liquid carrying rate, then carries out secondary fixation in a non-aqueous environment under low liquid carrying rate, the dye is fixed on the fabric, not only a very high fixation rate is obtained, but also the dyeing uniformity and color fastness of the fabric are guaranteed. At the same time, compared to traditional dyeing process, this method also greatly reduces the water consumption after fabric dyeing, greatly saves water resources, and does not need to use chemical materials such as sodium sulfate, saves the use of chemicals. In addition, the fabric continuous dyeing method provided by the present invention uses the process of electromagnetic wave pre-fixation-non-aqueous environment secondary fixation, greatly shortens dyeing time, just can complete dyeing in 10 minutes at the fastest, compared to traditional dyeing process, process time is greatly shortened, is very conducive to industrialized production. Finally, this method also has the advantages of simple and easy operation steps, simple process, low difficulty, short time consumption, high equipment utilization rate, environmentally friendly and energy-saving process, and easy industrial promotion, and has considerable economic advantages.

[0032] The dyed fabric obtained by the above-mentioned continuous fabric dyeing method not only has a high color fixation rate, but also has very excellent dyeing uniformity, and has uniform color, natural color and good color fastness. DETAILED DESCRIPTION

[0033] It should be noted that the term "comprise" and any variations thereof in the description and claims of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or are inherent to these processes, methods, products or apparatus.

[0034] The "range" disclosed in the present invention is given in the form of a lower limit and an upper limit. It can be one or more lower limits, and one or more upper limits respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower limit and upper limit define the boundaries of a particular range. All ranges defined in this way are combinable, i.e., any lower limit can be combined with any upper limit to form a range. For example, a range of 60-120 and 80-110 is listed for a particular parameter, and it is understood that a range of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​listed are 1 and 2, and the maximum range values ​​listed are 3, 4, and 5, then the following ranges can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.

[0035] In the present invention, unless otherwise specified, the numerical range "ab" is an abbreviation for any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" are listed in this invention, and "0-5" is merely an abbreviation for these numerical combinations.

[0036] In the present invention, unless otherwise specified, all embodiments and preferred embodiments mentioned in the present invention can be combined with each other to form a new technical solution.

[0037] In the present invention, unless otherwise specified, all technical features and preferred features mentioned in the present invention can be combined with each other to form a new technical solution.

[0038] In the present invention, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially. For example, the method comprising steps (a) and (b) indicates that the method may comprise steps (a) and (b) performed sequentially, or may comprise steps (b) and (a) performed sequentially. For example, the method further comprising step (c) indicates that step (c) may be added to the method in any order, for example, the method may comprise steps (a), (b) and (c), or may comprise steps (a), (c) and (b), or may comprise steps (c), (a) and (b), etc.

[0039] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the attached table and examples. The following embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the examples, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0040] Example 1

[0041] This embodiment provides a continuous dyeing method for cotton fabric, wherein the continuous dyeing method for cotton fabric comprises:

[0042] Step (1): using 450 mL of N,N-dimethylformamide and 50 mL of water as a polar solvent, and using the polar solvent to dissolve 20 g of reactive red and 15 g of sodium carbonate, then adding 2 g of penetrant WET to the resulting mixture and stirring evenly to obtain a dye solution, adding cotton fabric to the dye solution, dipping and padding, and controlling the liquid carrying rate to be 100%;

[0043] Step (2): Using electromagnetic waves to pre-fix the cotton fabric obtained in step (1). During the pre-fixing process, the power of the electromagnetic waves changes from high to low along with the movement direction of the cotton fabric; wherein the high power of the electromagnetic waves is 10W / cm 2 , the cotton fabric was treated for 30s under this power condition, and the low power was 0.5W / cm 2 , the cotton fabric was treated for 2.5 minutes under this power condition; after pre-fixation, the liquid pick-up rate of the cotton fabric was reduced to 10%;

[0044] Step (3): placing the cotton fabric obtained in step (2) in n-dodecane and performing secondary color fixation on the cotton fabric obtained in step (2) in n-dodecane at 90° C. for 10 minutes, squeezing out excess n-dodecane solvent, and then drying the fabric;

[0045] Step (4): neutralize the cotton fabric obtained in step (3) with 1 g / L acetic acid at 45° C. for 10 minutes, and then perform color fixing, softening and drying to obtain the finished dyed cotton fabric.

[0046] Example 2

[0047] This embodiment provides a continuous dyeing method for cotton fabric, wherein the continuous dyeing method for cotton fabric comprises:

[0048] Step (1): using 100 mL of dimethyl sulfoxide and 375 mL of water as a polar solvent, and dissolving 25 g of reactive black in the polar solvent, adding 12 mL of a sodium silicate solution with a concentration of 40°Bé, 2 mL of a sodium hydroxide solution with a concentration of 50 wt%, and 3 g of a penetrant SKS, stirring evenly to obtain a dye liquor, adding cotton fabric to the dye liquor, dipping and padding, and controlling the liquid carrying rate to be 100%;

[0049] Step (2): Pre-fix the cotton fabric obtained in step (1) with electromagnetic waves. During the pre-fixing process, the power of the electromagnetic waves changes from high to low along with the movement direction of the cotton fabric. The high power of the electromagnetic waves is 6W / cm 2 , the cotton fabric was treated for 40s under this power condition, and the low power was 1W / cm 2 , the cotton fabric was treated for 2.5 minutes under this power condition; after pre-fixation, the liquid pick-up rate of the cotton fabric was reduced to 10%;

[0050] Step (3): placing the cotton fabric obtained in step (2) in isopentyl isovalerate and performing secondary color fixation at 80° C. for 5 minutes, rolling out excess isopentyl isovalerate solvent, and then drying the cotton fabric;

[0051] Step (4): neutralize the cotton fabric obtained in step (3) with 1 g / L acetic acid at 45° C. for 10 minutes, and then perform color fixing, softening and drying to obtain the finished dyed cotton fabric.

[0052] Example 3

[0053] This embodiment provides a continuous dyeing method for cotton fabric, wherein the continuous dyeing method for cotton fabric comprises:

[0054] Step (1): using 100 mL of isopropyl alcohol and 400 mL of water as a polar solvent, and using the polar solvent to dissolve 15 g of active golden yellow, 2 g of sodium hydroxide and 7 g of sodium carbonate, then adding 2 g of penetrant SKS to the resulting mixture and stirring evenly to obtain a dye solution, adding cotton fabric to the dye solution, dipping and padding, and controlling the liquid carrying rate to be 100%;

[0055] Step (2): Pre-fix the cotton fabric obtained in step (1) with electromagnetic waves. During the pre-fixing process, the power of the electromagnetic waves changes from high to low along with the movement direction of the cotton fabric. The high power of the electromagnetic waves is 5W / cm 2 , the cotton fabric was treated for 60s under this power condition, and the low power was 0.5W / cm 2 , the cotton fabric was treated for 2.5 minutes under this power condition; after pre-fixation, the liquid pick-up rate of the cotton fabric was reduced to 10%;

[0056] Step (3): placing the cotton fabric obtained in step (2) in isododecane and performing secondary color fixation on the cotton fabric obtained in step (2) in isododecane at 90° C. for 5 minutes, squeezing out excess isododecane solvent, and then drying the fabric;

[0057] Step (4): neutralize the cotton fabric obtained in step (3) with 1 g / L acetic acid at 45° C. for 10 minutes, and then perform color fixing, softening and drying to obtain the finished dyed cotton fabric.

[0058] Example 4

[0059] This embodiment provides a continuous dyeing method for cotton fabric, wherein the continuous dyeing method for cotton fabric comprises:

[0060] Step (1): using 100 mL of acetonitrile and 400 mL of water as a polar solvent, and using the polar solvent to dissolve 20 g of active crimson, 1 g of potassium hydroxide and 6 g of sodium hydroxide, then adding 2 g of penetrant SKS to the resulting mixture and stirring uniformly to obtain a dye solution, adding cotton fabric to the dye solution, dipping and padding, and controlling the liquid carrying rate to be 100%;

[0061] Step (2): Pre-fix the cotton fabric obtained in step (1) with electromagnetic waves. During the pre-fixing process, the power of the electromagnetic waves changes from high to low along with the movement direction of the cotton fabric. The high power of the electromagnetic waves is 5W / cm 2 Under this power condition, the cotton fabric was treated for 60s, and the low power was 1.5W / cm 2 , the cotton fabric was treated for 1.5 minutes under this power condition; after pre-fixation, the liquid pick-up rate of the cotton fabric was reduced to 10%;

[0062] Step (3): placing the cotton fabric obtained in step (2) in methyl laurate for secondary color fixation at 90° C. for 5 minutes, rolling out excess methyl laurate, and then drying the fabric;

[0063] Step (4): neutralize the cotton fabric obtained in step (3) with 1 g / L acetic acid at 45° C. for 10 minutes, and then perform color fixing, softening and drying to obtain the finished dyed cotton fabric.

[0064] Example 5

[0065] This embodiment provides a continuous dyeing method for cotton fabrics, which differs from embodiment 1 only in that:

[0066] Step (2): Pre-fix the cotton fabric obtained in step (1) with electromagnetic waves. During the pre-fixing process, the power of the electromagnetic waves remains unchanged along with the movement direction of the cotton fabric. The power of the electromagnetic waves is 10W / cm 2 , the cotton fabric was treated for 3 minutes under this power condition.

[0067] Example 6

[0068] This embodiment provides a continuous dyeing method for cotton fabrics, which differs from embodiment 1 only in that:

[0069] Step (2): Pre-fix the cotton fabric obtained in step (1) with electromagnetic waves. During the pre-fixing process, the power of the electromagnetic waves remains unchanged along with the movement direction of the cotton fabric. The power of the electromagnetic waves is 0.5W / cm 2 , the cotton fabric was treated for 3 minutes under this power condition.

[0070] Example 7

[0071] This embodiment provides a continuous dyeing method for cotton fabrics, which differs from embodiment 1 only in that:

[0072] Step (2): Pre-fix the cotton fabric obtained in step (1) with electromagnetic waves. During the pre-fixing process, the power of the electromagnetic waves changes from low to high along with the movement direction of the cotton fabric. The low power of the electromagnetic waves is 0.5W / cm 2 Under this power condition, the cotton fabric was treated for 2.5 minutes, and the high power of the electromagnetic wave was 10W / cm 2 , the cotton fabric was treated for 30s under this power condition.

[0073] Comparative Example 1

[0074] This comparative example provides a traditional water dyeing method for cotton fabrics, wherein the traditional water dyeing method for cotton fabrics comprises:

[0075] Take 0.5g reactive red and 70g / L (based on the total volume of the dye solution) sodium sulfate, prepare a dye solution according to a bath ratio of 1:12, add 10g of cotton fabric after conventional pretreatment, and keep it at 45°C for 30 minutes, then raise the temperature to 60°C and add 20g / L (based on the total volume of the dye solution) of soda ash, continue to keep warm for 1h, and after dyeing is completed, wash the cloth with water and soap to obtain the finished dyed cotton fabric.

[0076] Comparative Example 2

[0077] This comparative example provides a continuous dyeing method for cotton fabric, wherein the continuous dyeing method for cotton fabric comprises:

[0078] Step (1): using 100 mL of acetonitrile and 400 mL of water as a polar solvent, and using the polar solvent to dissolve 20 g of active crimson, 1 g of potassium hydroxide and 6 g of sodium hydroxide, then adding 2 g of penetrant SKS to the resulting mixture and stirring uniformly to obtain a dye solution, adding cotton fabric to the dye solution, dipping and padding, and controlling the liquid carrying rate to be 100%;

[0079] Step (2): Using electromagnetic waves to pre-fix the cotton fabric obtained in step (1). During the pre-fixing process, the power of the electromagnetic waves changes from high to low along with the movement direction of the cotton fabric; wherein the high power of the electromagnetic waves is 10W / cm 2 , the cotton fabric was treated for 30s under this power condition, and the low power was 0.5W / cm 2 , under this power condition, cotton fabric was treated with electromagnetic waves for 2.5 minutes; after pre-fixation, the liquid pick-up rate of cotton fabric was reduced to 10%;

[0080] Step (3): After dyeing is completed, the cloth is washed with water and soaped in sequence to obtain the finished dyed cotton fabric.

[0081] Comparative Example 3

[0082] This comparative example provides a continuous dyeing method for cotton fabric, wherein the continuous dyeing method for cotton fabric comprises:

[0083] Step (1): using 100 mL of acetonitrile and 400 mL of water as a polar solvent, and using the polar solvent to dissolve 20 g of active crimson, 1 g of potassium hydroxide and 6 g of sodium hydroxide, then adding 2 g of penetrant SKS to the resulting mixture and stirring uniformly to obtain a dye solution, adding cotton fabric to the dye solution, dipping and padding, and controlling the liquid carrying rate to be 100%;

[0084] Step (2): placing the cotton fabric obtained in step (1) into methyl laurate and fixing the cotton fabric obtained in step (1) in methyl laurate at 90° C. for 10 minutes, rolling out excess methyl laurate and then drying the fabric;

[0085] Step (3): After dyeing is completed, the cloth is washed with water and soaped in sequence to obtain the finished dyed cotton fabric.

[0086] Comparative Example 4

[0087] This comparative example provides a continuous dyeing method for cotton fabric, wherein the continuous dyeing method for cotton fabric comprises:

[0088] Step (1): using 100 mL of acetonitrile and 400 mL of water as a polar solvent, and using the polar solvent to dissolve 20 g of active crimson, 1 g of potassium hydroxide and 6 g of sodium hydroxide, then adding 2 g of penetrant SKS to the resulting mixture and stirring uniformly to obtain a dye solution, adding cotton fabric to the dye solution, dipping and padding, and controlling the liquid carrying rate to be 100%;

[0089] Step (2): placing the cotton fabric obtained in step (1) into methyl laurate and fixing the cotton fabric obtained in step (2) in methyl laurate at 90° C. for 10 minutes, and rolling out excess methyl laurate.

[0090] Step (3) uses electromagnetic waves to perform secondary color fixing on the cotton fabric obtained in step (2). During the color fixing process, the power of the electromagnetic waves changes from high to low along with the movement direction of the cotton fabric; wherein the high power of the electromagnetic waves is 10W / cm 2 Under this power condition, the cotton fabric is treated for 30s, and the low power of the electromagnetic wave is 0.5W / cm 2 , the cotton fabric was treated for 2.5 minutes under this power condition.

[0091] Step (4): After dyeing is completed, the cloth is washed with water and soaped in sequence to obtain the finished dyed cotton fabric.

[0092] Performance Test Example 1

[0093] This performance test example uses conventional methods available in the art to test parameters such as color fastness, dry rubbing fastness, and wet rubbing fastness of the dyed cotton fabrics provided in Examples 1 to 7 of the present invention and Comparative Examples 1 to 4.

[0094] The experimental data measured in this performance test example and the recorded fixing time data of Examples 1 to 7 of the present invention and Comparative Examples 1 to 4 are shown in Table 1 below.

[0095] Table 1

[0096]

[0097] Combining the results of visual observation and the experimental data shown in Table 1 above, it can be seen that the dyed cotton fabrics provided by the embodiments of the present invention are uniform in color. Specifically, the dyed cotton fabrics provided by the embodiments of the present invention have a color fixation rate of more than 78%, a dry rubbing fastness of more than 4.0, and a wet rubbing fastness of more than 3.0. Compared with Examples 5 to 7, in Examples 1 to 4 of the present invention, electromagnetic waves are used to pre-fix the fabric. At the same time, during the pre-fixing process, the power of the electromagnetic wave changes from high to low with the movement direction of the fabric. Not only are the dyed cotton fabrics uniform in color, but the color fixation rate, dry rubbing fastness, and wet rubbing fastness are also better. Specifically, the color fixation rate of the dyed cotton fabrics in Examples 1 to 4 of the present invention is as high as more than 97%, the dry rubbing fastness is more than 4.5, and the wet rubbing fastness is more than 3.0.

[0098] Although the dyed cotton fabric provided in Comparative Example 1 has a relatively uniform color, its color fixation rate is only 56%. Therefore, it can be seen that the dyeing performance and color fixation rate of the dyed cotton fabric provided in Comparative Example 1 are significantly lower than those of the embodiment of the present invention.

[0099] Compared with the dyed cotton fabric provided in Example 4 of the present invention, although the dyed cotton fabric provided in Comparative Example 2 also has a more uniform color, its color fixation rate is only 67%, and its wet rubbing fastness is only level 2.5.

[0100] Compared with the dyed cotton fabric provided in Example 4 of the present invention, the dyed cotton fabric provided in Comparative Example 3 not only has serious color mottle, but also has a color fixation rate as low as 51%, and a wet rubbing fastness of only 2.5.

[0101] Compared with the dyed cotton fabric provided in Example 4 of the present invention, the dyed cotton fabric provided in Comparative Example 4 has a color fixation rate of only 53%, a dry rubbing fastness of only level 3.0, and a wet rubbing fastness of only level 2.5. Moreover, the K / S difference and the color difference of each area of ​​the fabric surface are high, the levelness is poor, and the color mottle is serious.

[0102] By comparing the experimental results of Example 4 of the present invention with Comparative Examples 2 to 4, it can be seen that the continuous fabric dyeing method provided by the present invention combines electromagnetic wave pre-fixation and secondary fixation in a non-aqueous environment, which not only achieves a high fixation rate but also ensures the dyeing uniformity of the fabric.

[0103] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, substitutions of equivalent components, or equivalent changes and modifications made within the scope of patent protection, should still fall within the scope of this patent. Furthermore, the technical features of this invention may be freely combined with one another, with other technical inventions, and with other technical inventions.

Claims

1. A continuous fabric dyeing method, wherein: The continuous fabric dyeing method comprises: Step (1): applying dye liquor to the fabric; Step (2): using electromagnetic waves to pre-fix the fabric to reduce the liquid pick-up rate, ensure uniform coloring of the fabric, and fix part of the dye on the fabric; Step (3): performing secondary color fixing on the fabric in a non-aqueous environment; Step (4): neutralizing, post-treating and drying the fabric after secondary color fixation to complete the continuous dyeing of the fabric.

2. The continuous dyeing method for fabrics according to claim 1, wherein: In step (2), the electromagnetic waves include microwaves and / or radio frequencies.

3. The continuous dyeing method for fabrics according to claim 1 or 2, wherein: In step (2), the frequency of the electromagnetic wave is 10-3000 MHZ, and the power per unit area is 0.5-50 W / cm 2 The electromagnetic wave pre-fixing time is 0.5-20 minutes.

4. The continuous dyeing method for fabrics according to claim 3, wherein: In step (2), during the pre-fixing process, the power of the electromagnetic wave changes from high to low along with the direction of fabric movement; wherein the high power range of the electromagnetic wave is 5-50W / cm 2 Under this power condition, the fabric is treated for 10-180s, and the low power range is greater than 0.5W / cm 2 And less than 5W / cm 2 The fabric is treated under this power condition for 1-10 minutes.

5. The continuous dyeing method for fabrics according to any one of claims 1 to 2, 4, wherein: In step (2), during the pre-fixation process, the liquid carrying rate is reduced to 0-20%.

6. The continuous dyeing method for fabrics according to claim 1, wherein: In step (3), the non-aqueous environment is provided by a liquid non-aqueous medium or a gaseous non-aqueous medium, wherein the non-aqueous medium includes one or a combination of alkanes, halogenated aliphatic hydrocarbons, aromatic hydrocarbons, ketone solvents, silane solvents, ester solvents, liquid paraffin, ether solvents and supercritical carbon dioxide.

7. The continuous dyeing method for fabrics according to claim 1 or 6, wherein: In step (3), the temperature of the secondary color fixation is 60-120° C., and the time is 5-120 min.

8. The continuous fabric dyeing method according to claim 1, wherein: In step (1), the dye solution comprises a reactive dye, an inorganic base, a penetrant and a polar solvent; Preferably, the inorganic base comprises one or a combination of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and sodium silicate; more preferably, the amount of the inorganic base is 5-50 g / L based on the total volume of the dye liquor; Also preferably, the polar solvent includes one or a combination of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, acetonitrile, ethanol, isopropanol, ionic liquids, alcohol ether solvents, ester solvents and water.

9. The continuous dyeing method for fabrics according to claim 1 or 8, wherein: In step (1), the application method includes one or a combination of spraying, padding and spraying; Preferably, the fabric comprises a fabric formed from cellulose fibers or blended fibers thereof; Also preferably, the fabric is in the form of grey cloth or semi-bleached cloth.

10. A dyed fabric obtained by the continuous fabric dyeing method according to any one of claims 1 to 9.

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