Production method of colored weft jean fabric

Abstract

The invention relates to the technical field of denim fabrics, and provides a production method of a colored-weft denim fabric, which comprises the following steps: weaving, finishing, washing and dyeing a finished product of weft yarns and warp yarns dyed by indigo to obtain the colored-weft denim fabric, the weft yarns are cation modified cotton; the cation modified cotton is obtained by modifying cotton fiber I with a cation compound solution; cationic compounds in the cationic compound solution comprise coconut oil alkyl dimethyl benzyl ammonium chloride, lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride and methacryloyloxyethyl trimethyl ammonium chloride. By means of the technical scheme, the problem that in the prior art, denim is poor in washing resistance is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of denim fabrics, and specifically, to a production method of a color-weft denim fabric. Background Art

[0002] Traditional denim fabrics are woven from indigo-dyed warp yarns and off-white weft yarns. With the diversification and personalization of social life, people's diverse demands for denim clothing are increasing day by day. Denim fabrics are continuously developing towards a rich color direction. Color-weft denim has also emerged as the times require. It is combined with processes such as slashing warp and exposing weft, cuff hemming, or front-back splicing in denim clothing processing, adding embellishments to the richness of denim clothing and being widely welcomed by the market.

[0003] Currently, the color-weft denim on the market is achieved by weaving in color weft yarns during production. The sources of color weft yarns are mainly colored spun yarns or cheese yarns dyed with reactive dyes. This kind of color-weft denim has several problems: First, the color of the color weft yarns is single and suitable for mass production. In recent years, the clothing market has shown the characteristics of small orders and quick returns. Large quantities of single-color weft yarn varieties are not convenient for the rapid conversion of clothing with multiple color weft yarns, with poor market flexibility, and will cause raw material or finished product inventory in garment factories, resulting in capital occupation and even waste. Second, because most denim fabrics need to be re-washed after being made into clothing, and the chlorine bleach resistance of cotton weft yarns dyed with reactive dyes is unstable, and they will decolorize or change color during the washing process of denim clothing. Therefore, some denim clothing with weft yarns dyed with reactive dyes cannot be washed, and thus cannot present diverse denim washing effects, restricting the application of color-weft denim. Third, the reactive dyeing of weft yarns uses the dipping process, and a large amount of salt, soda ash, and fixing agent need to be used in the dyeing solution, and the deeper the color, the greater the dosage. Since a large amount of inorganic salts used in the dyeing process cannot be recycled and degraded, the wastewater treatment after dyeing is difficult, and it is easy to cause environmental pollution. Therefore, it is necessary to provide a color-weft denim fabric with water-wash resistance to expand the application of color-weft denim. Summary of the Invention

[0004] The present invention provides a production method of a color-weft denim fabric, which solves the problem of poor water-wash resistance of denim in the related art.

[0005] The technical solution of the present invention is as follows: The present invention provides a production method of a color-weft denim fabric, including the following steps: weaving, finishing, washing, and finished product dyeing of weft yarns and indigo-dyed warp yarns to obtain a color-weft denim fabric; the weft yarn is cation-modified cotton; the cation-modified cotton is obtained by modifying cotton fiber I with a cationic compound solution; the cationic compounds in the cationic compound solution include coconut oil alkyl dimethyl benzyl ammonium chloride, lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride, and methacryloyloxyethyl trimethyl ammonium chloride.

[0006] As a further technical solution, the sum of the masses of coconut alkyl dimethyl benzyl ammonium chloride, lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride, and methacryloyloxyethyl trimethyl ammonium chloride is 5% to 8% of the mass of cotton fiber.

[0007] As a further technical solution, the mass ratio of coconut alkyl dimethyl benzyl ammonium chloride, lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride, and methacryloyloxyethyl trimethyl ammonium chloride is 0.5 to 2.5:1:2.

[0008] As a further technical solution, the mass ratio of coconut alkyl dimethyl benzyl ammonium chloride, lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride, and methacryloyloxyethyl trimethyl ammonium chloride is 1.5:1:2.

[0009] In the present invention, through the combined action of three cationic compounds as modifiers, abundant positive charges are introduced on the surface of cotton fiber. Cationic dyes in the dye solution will be better adsorbed on the surface of cotton fiber. Compared with unmodified cotton fiber, the positive charge environment on the surface of the cation-modified cotton fiber in the present invention enables dye molecules to more easily overcome the resistance of the dyes and be adsorbed on the cotton fiber quickly and firmly, improving the efficiency and effect of adsorption dyeing and still having high color fastness after multiple water washes.

[0010] As a further technical solution, the preparation method of the cationic compound solution is: after mixing the cationic compound with water, adjusting the pH to 7.5 to 8.5 to obtain the cationic compound solution.

[0011] In the preparation process of the cationic compound solution in the present invention, using sodium hydroxide solution to adjust the pH of the cationic compound solution can provide a suitable pH for the solution system during the modification process and can improve the wash fastness of denim fabric.

[0012] As a further technical solution, the warp used in the indigo-dyed warp includes pure spun yarn of one of cotton fiber II, viscose fiber, lyocell fiber, and modal fiber, or blended yarn of two or more of them; cotton fiber II includes one of pure cotton yarn, elastic core-spun yarn, and elastic double-covered yarn.

[0013] As a further technical solution, the indigo-dyed warp is obtained by warping, scouring, water washing, dyeing, further water washing, and drying of the warp. The method used for warping is sectional warping or beam warping; the method used for dyeing is piece dyeing or rope dyeing.

[0014] As a further technical solution, the solvent used for scouring is caustic soda at 6 to 8 g / L, and the scouring temperature is 60°C.

[0015] As a further technical solution, the water wash uses soft water, and the temperature of the water wash is normal temperature.

[0016] As a further technical solution, the dyeing reagent used for the dyeing is an indigo dyeing solution of 2.6 g / L, the ORP of the dyeing is -740 to -760 mV, the pH is 11.6 to 11.8, and the temperature of the dyeing is normal temperature.

[0017] As a further technical solution, the number of times of the dyeing is 9 times.

[0018] As a further technical solution, the water wash uses soft water, and the temperature of the water wash is normal temperature.

[0019] As a further technical solution, the number of times of the water wash is 3 times.

[0020] As a further technical solution, the weaving process includes one of twill, satin, combined weave, complex weave, jacquard weave, etc., specifically it can be 3 / 1 right twill.

[0021] As a further technical solution, the finishing includes one or more of the processes such as singeing, mercerizing, desizing, bleaching, stentering, air softening finishing, shrink-proof processing, setting, etc.

[0022] As a further technical solution, the singeing process is carried out in a way of one positive and one negative two burners, and the vehicle speed of the burners is 70 m / min.

[0023] As a further technical solution, the desizing process uses high-temperature desizing enzyme for desizing, and the high-temperature desizing enzyme is amylase.

[0024] As a further technical solution, the addition amount of the high-temperature desizing enzyme is 5%, and the temperature of the high-temperature desizing is 60 °C.

[0025] As a further technical solution, the temperature of the setting process is 150 °C.

[0026] As a further technical solution, the process of the water wash is as follows: after carrying out desizing treatment in soap oil, the first water wash is carried out; after carrying out stone washing, the second water wash is carried out; after rinsing and debleaching, the third water wash is carried out; after dehydration and drying, spraying monkey, neutralizing wash, and the fourth water wash is carried out.

[0027] As a further technical solution, when carrying out stone washing, the substances used are composed of enzyme, water and pumice.

[0028] As a further technical solution, the mass ratio of the enzyme, water and pumice is 1:1000:50.

[0029] In the present invention, each step in the water washing process complements each other, improving the quality and appearance of the denim fabric. Desizing treatment is carried out in the soap oil. The emulsifying, penetrating and decontaminating properties of the soap oil can effectively remove the sizing agent attached to the surface of the denim fabric during the manufacturing process, preparing for subsequent water washing treatment, ensuring that the treatment agent used in the subsequent steps can better act on the cotton fibers and improving the treatment effect. The first water washing can timely remove the residual sizing agent and soap oil after desizing treatment, avoiding their influence on subsequent processing.

[0030] In the bio-stone washing process, the bio-enzyme hydrolyzes the fibers to improve the hand feeling, and the stone friction makes the fabric fade and fuzz, creating a vintage appearance. The second water washing cleans impurities such as fiber debris, residual enzyme preparations and stone wear particles generated during the bio-stone washing process, ensuring the fabric is clean, and at the same time consolidating the effects of bio-washing and stone washing, making the fading and fuzzing more natural and uniform. Rinsing further removes the fine impurities and chemicals remaining on the fabric, enabling the fabric to have no hindrance in subsequent processing. The third water washing cleans again to ensure that the fabric enters subsequent processing in a pure state.

[0031] Dehydration and drying make the fabric reach an appropriate water content, facilitating the operation of spraying monkey. Spraying monkey sprays solutions such as potassium permanganate on the fabric through a spray gun to achieve local fading and create unique patterns and wear effects. Neutralizing wash uses acidic substances to neutralize the residues of alkaline substances such as potassium permanganate to prevent fabric damage and stabilize the color at the same time. The fourth water washing removes substances such as salts generated during the neutralization process, ensuring the final safety and stability of the fabric, and the cumulative effect of multiple water washings makes the appearance and hand feeling of the fabric more in line with the requirements of high-quality denim products.

[0032] As a further technical solution, the temperature of the desizing treatment is 45 - 60 °C, and the time of the desizing treatment is 10 - 20 min.

[0033] As a further technical solution, the temperature of the first water washing is room temperature, and the time of the first water washing is 5 - 15 min.

[0034] As a further technical solution, the temperature of the bio-stone washing is 20 - 45 °C, and the time of the bio-stone washing is 30 min.

[0035] As a further technical solution, the temperature of the second water washing is room temperature, and the time of the second water washing is 5 - 15 min.

[0036] As a further technical solution, the mass concentration of the bleaching liquid used for rinsing is 30 - 50 g / L, the solute of the bleaching liquid is sodium hypochlorite, the pH is 10 - 12, the temperature of rinsing is 20 - 50 °C, and the time of rinsing is 10 - 20 min.

[0037] As a further technical solution, the time of decolorizing rinse is 5 min.

[0038] As a further technical solution, the temperature of the third water wash is normal temperature, and the time of the third water wash is 5 - 15 min.

[0039] As a further technical solution, the potassium permanganate phosphoric acid aqueous solution is used for the monkeying; the preparation method of the potassium permanganate phosphoric acid aqueous solution is: mixing potassium permanganate, phosphoric acid and water with a mass ratio of 1:1:33 evenly to obtain the potassium permanganate phosphoric acid aqueous solution.

[0040] As a further technical solution, the neutralization wash uses an aqueous solution of sodium metabisulfite with a concentration of 1.5 - 2 g / L, the temperature of the aqueous solution of sodium metabisulfite is normal temperature, and the time of the neutralization wash is 5 - 15 min.

[0041] As a further technical solution, the temperature of the fourth water wash is room temperature, and the time of the fourth water wash is 5 - 15 min.

[0042] As a further technical solution, the process of the finished product dyeing is to first dye with reactive dyes, and then carry out water washing, softening and drying.

[0043] As a further technical solution, the reactive dyes include one or more of reactive dark red dyes, reactive dark blue dyes, and reactive yellowish brown dyes.

[0044] As a further technical solution, the temperature of the dyeing is 45 - 60 °C, and the time of the dyeing is 10 - 20 min.

[0045] As a further technical solution, the water wash is carried out using soap oil and washing powder, the temperature of the water wash is normal temperature, and the time of the water wash is 5 - 15 min.

[0046] The present invention also provides a color - weft denim fabric, which is produced by the production method of the color - weft denim fabric.

[0047] The working principle and beneficial effects of the present invention are as follows: In the present invention, cation - modified cotton is applied to the weft yarn of the denim fabric. Utilizing the dyeing characteristics of the modified cotton, the weft yarn is dyed while the warp yarn color is not affected. There are a large number of hydroxyl groups on the side chain of the natural cotton fiber macromolecule. During the dyeing process, some hydroxyl groups will hydrolyze in the aqueous solution, making the cotton fiber as a whole negatively charged. The dye anions will repel the negative charges on the cotton fiber, resulting in weak adsorption of anionic dyes (such as reactive dyes, direct dyes, etc.). In the traditional dyeing process, in order to improve the dye uptake rate and fixation rate of reactive dyes, a large amount of inorganic salts need to be added to weaken the repulsion between the dye anions and the negative charges on the cotton fiber.

[0048] In the present invention, the principle of modified cotton is to introduce cationic groups to react with the functional groups on the cellulose fiber molecules, reducing the Coulomb repulsion between the anionic groups of dyes and the negatively charged groups of fibers. At the same time, a large number of cationic groups present on the macromolecules of the modified cotton fibers have an active adsorption effect on anionic dyes, significantly improving the dye uptake rate. And when there are both modified cotton weft yarns and unmodified warp yarns in the dyeing solution, the weft yarns actively adsorb dyes with good coloration effects. The warp yarns do not have a promoting dyeing environment of high salt and high alkali and repel anionic dyes, so they will not be dyed, making the denim fabric more colorful and fashionable in appearance. And by defining the cationic compound as coconut alkyl dimethyl benzyl ammonium chloride and lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride, it can better improve the adsorption of cationic modified cotton to dyes and has better wash fastness performance.

[0049] The present invention solves the problem that traditional colored weft denim cannot be bleached. The washing effects such as the bone positions, hand-rubbed positions, textures, and white showing of denim clothing will not be affected, and the washing development and processing of color depth and hand-rubbed styling can be freely carried out; the weft yarn coloring is carried out after the clothing is bleached, so there is no problem of bleaching and decolorization. The weft yarn colors are full and bright, and can be personalized designed according to the clothing styles and consumers' preferences, with flexible dyeing forms; the production of fabric factories is not restricted by the final colored weft colors, and fabrics can be produced in batches, which is conducive to reducing costs and improving efficiency. Garment factories can use the same fabric and produce a variety of colorful weft clothing in small batches according to different color requirements, forming a flexible production line, which is conducive to the personalized design and development of clothing and adapts to the current market rhythm of small orders and quick responses; the cotton fibers modified by cations can actively adsorb dyes, realizing salt-free, alkali-free, and normal-temperature dyeing, reducing the use of auxiliaries such as salt and alkali, effectively reducing the salt content in the wastewater of the washing factory, and is of great significance for saving resources and protecting the environment. Specific embodiments

[0050] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

[0051] In the following examples and comparative examples: The warp yarn is 10 English count ring-spun slub yarn, and the weft yarn is 12 English count stretch core-spun yarn.

[0052] Example 1 A production method of a colored weft denim fabric includes the following steps: S1. Warp Dyeing Process: Warping → Scouring [Caustic soda (6 g / L), 60 °C] → Water Washing [Soft water, normal temperature] → Dyeing [Indigo (2.6 g / L, ORP: -740 mV, pH: 11.6 - 11.8), normal temperature] × 9 → Water Washing [Soft water, normal temperature] × 3 → Drying to obtain indigo-dyed warp; S2. Mix the weft yarn with the cationic compound solution, heat it up to 50 °C, impregnate for 30 min, and dry to obtain cation-modified weft yarn; where the mass concentration of the cationic compound in the cationic compound solution is 10%, the cationic compound is 5% of the mass of the weft yarn, and the preparation method of the cationic compound solution is: Mix coconut oil alkyl dimethyl benzyl ammonium chloride, lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride, and methacryloyloxyethyl trimethyl ammonium chloride with a mass ratio of 0.5:1:2 evenly, and then adjust the pH to 7.5 to obtain the cationic compound solution; S3. After weaving the cation-modified weft yarn and the indigo-dyed warp using an OptiMax rapier loom (3-up 1-down right twill), carry out finishing. The finishing process: Gas singeing [In the way of one positive and one negative two burners, burner vehicle speed 70 m / min] → Desizing [High-temperature desizing enzyme - amylase (0.5%), 60 °C] × 2 → Shrinking prevention → Blanket setting [150 °C]; S4. The water washing process is: Desizing [Scouring agent, 15 min, 45 °C] → Water Washing [Water, 5 min, normal temperature] → Stone washing [The mass ratio of enzyme, water and pumice is 1:1000:50, 30 min, normal temperature] → Water Washing [Water, 5 min, normal temperature] → Bleaching [Sodium hypochlorite bleaching solution (40 g / L), adjusting pH with soda ash, pH controlled at 10, 45 °C, 10 min] → Unbleaching [Sodium thiosulfate (3 g / L), washing powder (commercially available), 5 min] → Water Washing [Water, 5 min, normal temperature] → Dehydration drying → Spraying monkey [Potassium permanganate phosphoric acid aqueous solution (obtained by mixing potassium permanganate, phosphoric acid and water with a mass ratio of 1:1:33)] → Neutralizing wash [Sodium metabisulfite (1.5 g / L), normal temperature, 8 min] → Water Washing [Water, 5 min, normal temperature]; S5. Garment dyeing process: Reactive dyeing [Reactive dye concentration 1% (owf), 10 min, 45 °C] → Water Washing [Scouring agent, washing powder, 5 min, normal temperature] → Softening → Drying → Color weft denim fabric.

[0053] Example 2 A production method of color weft denim fabric, including the following steps: S1. Warp Dyeing Process: Warping → Scouring [Caustic Soda (8 g / L), 60 °C] → Water Washing [Soft Water, Normal Temperature] → Dyeing [Indigo (2.6 g / L, ORP: -760 mV, pH: 11.6 - 11.8), Normal Temperature] × 9 → Water Washing [Soft Water, Normal Temperature] × 3 → Drying to obtain indigo-dyed warp; S2. Mix the weft yarn with a cationic compound solution, heat it up to 60 °C, impregnate it for 20 min, and dry it to obtain cation-modified weft yarn; wherein the mass concentration of the cationic compound in the cationic compound solution is 10%, and the cationic compound is 8% of the mass of the weft yarn. The preparation method of the cationic compound is: Mix coconut oil alkyl dimethyl benzyl ammonium chloride, lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride, and methacryloyloxyethyl trimethyl ammonium chloride with a mass ratio of 2.5:1:2 evenly, and then adjust the pH to 8.5 to obtain the cationic compound solution; S3. After weaving the cation-modified weft yarn and the indigo-dyed warp using an OptiMax rapier loom (3-up 1-down right twill), carry out finishing. The finishing process: Gas singeing [One positive and one negative two burners, burner vehicle speed 70 m / min] → Desizing [High-temperature desizing enzyme - amylase (0.5%), 60 °C] × 2 → Shrinking prevention → Blanket setting [150 °C]; S4. The water washing process is: Desizing [Oily soap, 15 min, 45 °C] → Water Washing [Water, 5 min, Normal Temperature] → Stone washing [The mass ratio of enzyme, water and pumice is 1:1000:5, 30 min, Normal Temperature] → Water Washing [Water, 5 min, Normal Temperature] → Bleaching [Sodium hypochlorite bleaching solution (40 g / L), adjusting pH with soda ash, pH controlled at 12, 45 °C, 10 min] → Unbleaching [Sodium thiosulfate (5 g / L), commercial washing powder, 5 min] → Water Washing [Water, 5 min, Normal Temperature] → Dehydration drying → Spraying monkey [Potassium permanganate phosphoric acid aqueous solution (obtained by mixing potassium permanganate, phosphoric acid and water with a mass ratio of 1:1:33)] → Neutralizing wash [Sodium metabisulfite (1.5 g / L), Normal Temperature, 8 min] → Water Washing [Water, 5 min, Normal Temperature]; S5. Garment dyeing process: Reactive dyeing [Reactive dye concentration 1% (owf), 10 min, 45 °C] → Water Washing [Oily soap, washing powder, 5 min, Normal Temperature] → Softening → Drying → Color weft denim fabric.

[0054] Example 3 Compared with Example 1, the difference in this example is only that the mass ratio of coconut oil alkyl dimethyl benzyl ammonium chloride, lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride, and methacryloyloxyethyl trimethyl ammonium chloride is 2.5:1:2.

[0055] Example 4 Compared with Example 1, the difference in this example is only that the mass ratio of cocodimethylbenzylammonium chloride, lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride, and methacryloyloxyethyl trimethyl ammonium chloride is 1.5:1:2.

[0056] Example 5 Compared with Example 1, the difference in this example is only that the pH of the cationic compound solution is 7.

[0057] Example 6 Compared with Example 1, the difference in this example is only that the pH of the cationic compound solution is 9.

[0058] Comparative Example 1 Compared with Example 1, the difference in this comparative example is only that the cation-modified weft yarn is replaced with an equal amount of unmodified weft yarn.

[0059] Comparative Example 2 Compared with Example 1, the difference in this comparative example is only that the cationic compound is only dodecyl trimethyl ammonium chloride.

[0060] Comparative Example 3 Compared with Example 1, the difference in this comparative example is only that the cationic compound is only cocodimethylbenzylammonium chloride.

[0061] Comparative Example 4 Compared with Example 1, the difference in this comparative example is only that the cationic compound is only lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride.

[0062] Comparative Example 5 Compared with Example 1, the difference in this comparative example is only that the cationic compound is only methacryloyloxyethyl trimethyl ammonium chloride.

[0063] Comparative Example 6 Compared with Example 1, the difference in this comparative example is only that the cationic compound is composed of cocodimethylbenzylammonium chloride and lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride with a mass ratio of 0.5:1.

[0064] Comparative Example 7 Compared with Example 1, the difference in this comparative example is only that the cationic compound is composed of cocodimethylbenzylammonium chloride and lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride with a mass ratio of 0.5:2.

[0065] Comparative Example 8 Compared with Example 1, the difference in this comparative example is only that the cationic compound consists of lauryl methyl glucitol polyether-10 hydroxypropyl dimethyl ammonium chloride and methacryloyloxyethyl trimethyl ammonium chloride with a mass ratio of 1:2.

[0066] Test Example 1 (1)Color fastness to water (grade): The color change was evaluated according to the determination method in GB / T 5713-2013 "Textiles - Color fastness tests - Color fastness to water". (2)Color fastness to alkaline perspiration (grade), color fastness to acid perspiration (grade): The color change and staining were determined according to the determination method in GB / T 3922-2013 "Textiles - Color fastness tests - Color fastness to perspiration". (3)Color fastness to rubbing (grade): The color change and staining were evaluated according to the determination method in GB / T 3920-2008 "Textiles - Color fastness tests - Color fastness to rubbing". The grades of color change of color fastness to water in Examples 1 to 6 and Comparative Examples 1 to 8 were measured, and the measurement results are shown in Table 1.

[0067] Table 1 Measurement Results

[0068] From the measurement results in Table 1, it can be obtained that the color fastness to water in Examples 1 to 6 of the present invention is all > 3 grades, indicating that the denim fabric in the present invention has good water resistance.

[0069] Test Example 2 The color fastness to abrasion, color fastness to acid perspiration, and color fastness to alkaline perspiration in Example 4 were measured, and the measurement results are shown in Table 2 below.

[0070] Table 2 Measurement Results

[0071] It can be seen from Table 2 that Example 4 of the present invention not only has a good grade of color fastness to water, but also has good grades in terms of color fastness to rubbing and color fastness to acid and alkaline perspiration, which can further expand the application range of the denim fabric.

[0072] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, 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 method for producing colored weft denim fabric, characterized in that: The following steps are involved: Weaving, finishing, washing and dyeing the weft yarn and the indigo-dyed warp yarn to obtain a colored weft denim fabric; the weft yarn is a cationic modified cotton; The cationic modified cotton is obtained by modifying cotton fiber I with a cationic compound solution; The cationic compound in the cationic compound solution includes coconut oil alkyl dimethyl benzyl ammonium chloride, lauryl methyl gluceth-10 hydroxypropyl dimethyl ammonium chloride, and methacryloyloxyethyl trimethyl ammonium chloride.

2. The method for producing colored weft denim fabric according to claim 1, characterized in that: The total mass of the coconut oil alkyl dimethyl benzyl ammonium chloride, lauryl methyl gluceth-10 hydroxypropyl dimethyl ammonium chloride and methacryloyloxyethyl trimethyl ammonium chloride is 5% to 8% of the mass of the cotton fiber.

3. The method for producing colored weft denim fabric according to claim 1, characterized in that: The mass ratio of the coconut oil alkyl dimethyl benzyl ammonium chloride, lauryl methyl gluceth-10 hydroxypropyl dimethyl ammonium chloride, and methacryloyloxyethyl trimethyl ammonium chloride is 0.5-2.5:1:

2.

4. The method for producing colored weft denim fabric according to claim 1, characterized in that: The preparation method of the cationic compound solution is: after mixing the cationic compound with water, adjusting the pH to 7.5-8.5, to obtain the cationic compound solution.

5. The method for producing colored weft denim fabric according to claim 1, characterized in that: The warp yarn used in the indigo-dyed warp yarn includes pure spun yarn of one of cotton fiber II, viscose fiber, lyocell fiber, and modal fiber, or blended yarn of two or more thereof; the cotton fiber II includes one of pure cotton yarn, elastic core-spun yarn, and elastic double-spun yarn.

6. The method for producing colored weft denim fabric according to claim 1, characterized in that: The indigo-dyed warp yarn is obtained by warping, scouring, washing, dyeing, washing again and drying. The warping method is batch warping or ball warping. The dyeing method is sheet dyeing or rope dyeing.

7. The method for producing colored weft denim fabric according to claim 1, characterized in that: The finishing process includes one or more processes such as singeing, mercerizing, desizing, bleaching, tentering, air softening finishing, shrink-proofing and the like.

8. The method for producing colored weft denim fabric according to claim 1, characterized in that: The washing process is as follows: after desizing in soap oil, the first washing is performed; after yeast stone washing, the second washing is performed; after rinsing and de-rinsing, the third washing is performed; After dehydration and drying, spray with horse chestnut, neutralize and wash, and then wash for the fourth time.

9. The method for producing colored weft denim fabric according to claim 1, characterized in that: The finished product dyeing process is to first dye it with reactive dyes, then wash it with water, soften it, and dry it.

10. A colored weft denim fabric, characterized in that: The fabric is produced by the method for producing a colored weft denim fabric as described in any one of claims 1 to 9.

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