Dyeing process of special yarn and application of dyeing process

Abstract

The invention discloses a special yarn dyeing process and application thereof. The special yarn dyeing process comprises the steps of singeing, reeling, mercerizing synergistic modification, scouring and bleaching, dyeing, dual fixation, neutralization, soft finishing, drying, rewinding and inspection and packaging. The mercerizing synergistic modification means that in the mercerizing process, a fiber reactive modifier is added in a specific alkali concentration stage; the double color fixation means that a rare-earth-based color fixing agent and a cationic polymer color fixing agent are sequentially used for treatment; according to the treated yarn, the color fastness to wet rubbing is greater than or equal to grade 4, the color fastness to alkali is greater than or equal to grade 4-5, and the color fastness to washing is greater than or equal to grade 4 (discoloring and staining). According to the dyeing process of the special yarn and the application of the dyeing process, the dyeing effect and the color fastness are remarkably improved through an innovative mercerizing synergetic fiber modification technology and a dual color fixing system, and the dyeing process can be applied to various types of yarn such as long stapled cotton high count yarn, functional fiber blended yarn, medical antibacterial yarn and high-elastic covering yarn; and the yarns can play a better role in different fields.

Description

Technical Field

[0001] The invention belongs to the technical field of dyeing technology, and particularly relates to a dyeing process for special yarn and application thereof. Background Art

[0002] Yarn dyeing is a crucial process in the textile industry. It not only imparts beautiful colors to yarns but also enhances their functionality, enabling them to meet the demands of diverse applications. Currently, yarn dyeing processes primarily include direct dyeing and transfer printing. Direct dyeing offers simplicity and low cost, but may result in less uniform color. Transfer printing, on the other hand, can achieve more refined patterns but requires a larger investment in equipment.

[0003] With the rapid development of society and the continuous improvement of people's living standards, consumers are increasingly demanding a richer and more diverse range of clothing colors and higher-quality fabrics. At the same time, various industries are placing increasingly stringent demands on yarn performance. Existing yarn dyeing processes have many shortcomings, making it difficult to meet the diverse market demands.

[0004] Problems with existing yarn dyeing processes: (1) Dyeing effect Color penetration: Traditional yarn dyeing methods, such as dyeing after the yarn is packaged into cones, are closely spaced. This prevents the color from penetrating deeply into the cone during dyeing, resulting in a low color sampling rate and unsatisfactory dyeing results. For example, in some dark dyeing applications, the color of the yarn inside the cone is often lighter, significantly different from the surface color, affecting the overall dyeing quality.

[0005] Color variation: In existing dyeing techniques, yarn dyeing often produces defects such as color variation, color fading, dark and light spots, and streaking. Repeated priming can lead to inaccurate amounts of primer added to each vat, resulting in variations in the vat and, in turn, color variation during dyeing. Furthermore, improper pH adjustment of the developer solution or excessively fast or slow coupling speeds can also result in poor dyeing.

[0006] (2) Color fastness Inadequate color fastness to wet friction: Many yarns lose color easily after wet friction, affecting the yarn's service life and appearance. This problem is particularly prominent in applications where frequent friction is required, such as cuffs and collars of clothing.

[0007] Color fastness to alkali and washing: In some special environments or washing conditions, yarns need to have good color fastness to alkali and washing. However, existing dyeing processes perform poorly in this regard. The color of the yarn easily fades when exposed to alkaline substances or after repeated washing, which cannot meet practical requirements.

[0008] To address the aforementioned issues with existing yarn dyeing processes, the present invention aims to provide a dyeing process for specialty yarns with excellent overall color fastness (specifically, color fastness to wet rubbing ≥ Grade 4 and color fastness to alkali ≥ Grade 4-5) and good physical properties, and its application. Through innovative mercerization-synergistic fiber modification technology and a dual color fixation system, the dyeing process significantly improves dyeing quality and color fastness, meeting market demand for high-quality specialty yarns. The dyeing process of this invention can be applied to a variety of yarn types, including long-staple cotton fine-count yarn, functional fiber blended yarn, medical antibacterial yarn, and high-elastic core-spun yarn, enabling these yarns to perform better in various applications. Summary of the Invention

[0009] Purpose of the invention: In order to overcome the above shortcomings, the purpose of the present invention is to provide a dyeing process for special yarns and its application, which is reasonably designed and significantly improves the dyeing effect and color fastness through innovative mercerization synergistic fiber modification technology and double color fixing system, thereby meeting the market demand for high-quality special yarns.

[0010] The purpose of the present invention is achieved through the following technical solutions: An application of a dyeing process for special yarns comprises the following steps: A dyeing process for special yarns comprises the following steps: S1: singeing the yarn; S2: The yarn is then reeled; S3: The yarn is then subjected to mercerization synergistic modification; the mercerization synergistic modification refers to adding a fiber reactive modifier during the alkali stage of the mercerization process; S4: The yarn is then scour and bleached; S5: The yarn is then dyed; S6: The yarn is then subjected to double color fixing, wherein the double color fixing refers to sequentially treating the yarn with a rare earth-based color fixing agent and a cationic polymer color fixing agent; S7: The yarn is then neutralized; S8: The yarn is then subjected to a softening finishing process; S9: The yarn is then dried, reeled, and finally inspected and packaged.

[0011] The present invention provides a complete process flow for dyeing special yarns, starting with singeing to remove fuzz on the yarn surface, making the yarn surface smoother, reducing pilling in subsequent processing, and improving the appearance quality of the yarn. Yarn shaking arranges the yarn into a suitable twisted shape, which is convenient for the operation of subsequent processes. Mercerizing synergistic modification increases the dye uptake and fixation rate of the dye, improves the surface properties of the fiber, and fundamentally improves the color fastness and dyeing uniformity. Scouring and bleaching remove impurities and natural pigments in the yarn, providing a good foundation for dyeing. Dyeing gives the yarn the desired color, and the dual color fixation system significantly improves the color fastness to wet abrasion, alkali and washing. Neutralization adjusts the pH value of the yarn, soft finishing gives the yarn a soft feel, and drying, rewinding, inspection and packaging ensure the quality of the yarn and facilitate storage and transportation. The entire process is closely linked, and can produce special yarns with excellent comprehensive color fastness and good physical properties. In actual production, the long-staple cotton high-count yarn dyed according to this process can meet high standards of color fastness to wet friction, color fastness to alkali and color fastness to washing, meeting the needs of high-end textiles.

[0012] Furthermore, in the dyeing process of the above-mentioned special yarn, in S1, the singeing is performed using a gas singeing machine, and the process parameters are: the flame intensity is a propane / air mixture ratio of 1: (5~10) and the blue flame height is 30~40mm; the burner temperature is 900~1100℃; the processing time is a single-side contact time of 0.5~1.0s; the cooling method is a water-cooled roller, and the surface temperature is reduced to below 50℃.

[0013] Using a gas singeing machine, by precisely controlling the propane / air mixture ratio, blue flame height, burner temperature, treatment time and cooling method, it can effectively remove the fuzz on the yarn surface while ensuring that the singeing grade reaches ≥ Level 4 (GB / T4802.1 standard) and the fiber weight loss rate is ≤0.3%.

[0014] Furthermore, in the dyeing process of the above-mentioned special yarn, in S2, the yarn is reeled using a reeling machine, and the process parameters are: the yarn frame circumference is 1~2m, the single twist weight is 400~500g, and the reeling tension is 0.1~0.2cN / dtex.

[0015] Appropriate yarn frame circumference and single twist weight facilitate the handling and management of the yarn in subsequent processes, while precise reeling tension ensures that the yarn is evenly stressed during the reeling process, avoiding stretching, deformation or relaxation of the yarn, thereby ensuring the uniformity and stability of the yarn.

[0016] Furthermore, in the dyeing process of the above-mentioned special yarn, in S3, the mercerization synergistic modification specifically includes the following contents: S31: Immerse the yarn in 120-150 g / L pre-expanded NaOH at 35-40°C, add 1.5-3.0% owf of fiber reactive modifier KH-560, and immerse for 30-60 seconds; S32: drain the pre-swelling liquid NaOH, and immediately immerse the yarn in 250-260 g / L NaOH at room temperature for 90-150 seconds to fully mercerize and swell in the presence of fiber reactive modifier KH-560; S33: Squeeze and then rinse with 80-100 g / L NaOH at 60-70°C for 60-100 seconds, then rinse with cold water, and finally soak in cold water for later use.

[0017] Adding fiber-reactive modifier KH-560 to a pre-swelling solution with a relatively low alkali concentration results in initial fiber expansion, facilitating modifier penetration. The modifier hydrolyzes under weak alkaline conditions, allowing its epoxy groups to react with cellulose hydroxyl groups or subsequent dye-reactive groups, improving dye uptake and fixation, reducing the formation of hydrolyzed dyes, and simultaneously improving fiber surface properties, lowering surface energy and coefficient of friction, enhancing color fastness (especially wet rubbing) and dyeing uniformity. Subsequent mercerization and swelling of the fibers in a high-concentration NaOH solution at room temperature further enhances the modification effect. Rinsing with hot, dilute alkali and then cold water stabilizes yarn dimensions and removes some modifiers and impurities.

[0018] Furthermore, in the dyeing process of the above-mentioned special yarn, in S4, the scouring and bleaching specifically include the following contents: first, bio-enzyme scouring is performed, and then, hydrogen peroxide bleaching is performed; wherein, the bio-enzyme scouring uses 0.5~1% owf alkaline pectate lyase, and the treatment conditions are: pH 8~9, 40~50°C, 40~60min; the hydrogen peroxide bleaching solution includes 8~10g / L hydrogen peroxide, 0.5~1g / L stabilizer EDDHA and an addition amount of 0.1~0.5% owf sodium polyaspartate, the treatment temperature is 90~100°C, the time is 30~60min, and the termination of hydrogen peroxide bleaching is judged to be ≥450mV when the monitoring solution redox potential is monitored.

[0019] Scouring and bleaching utilizes a combination of enzyme scouring and hydrogen peroxide bleaching. Enzymatic scouring uses alkaline pectate lyase to remove impurities such as pectin from the yarn under mild conditions, minimizing damage to the yarn fibers. Hydrogen peroxide bleaching further removes natural pigments from the yarn, resulting in excellent whiteness. By controlling the solution composition, treatment temperature, and duration of hydrogen peroxide bleaching, and by monitoring the solution's redox potential to ≥450mV as the termination point, we ensure consistent and stable bleaching results.

[0020] Furthermore, in the dyeing process of the above-mentioned special yarn, in S5, dyeing specifically includes the following contents: dyeing the yarn, first washing it with room temperature water after dyeing, and the treatment time is 5-10 min; then pickling, the pickling uses 1-2 g / L acetic acid, the temperature is 30-40 ° C, and the treatment time is 5-10 min; then bio-enzyme washing, the bio-enzyme washing uses 0.5-1.0 g / L protease, the pH is 5.5-6.0, the temperature is 40-50 ° C, and the treatment time is 15-20 min; then washing with hot water, the temperature is 70-80 ° C, and the treatment time is 15-20 min.

[0021] The dyeing process includes water washing, acid washing, enzyme washing, and hot water washing. Water washing removes loose dye and impurities from the yarn surface. Acid washing adjusts the yarn's pH. Enzyme washing specifically decomposes and hydrolyzes dyes and impurities, improving the removal efficiency of loose dye at low temperatures. Hot water washing further removes residual impurities and dye. The example dyeing recipe provided is suitable for medium to dark dyeing and can provide a reference for actual production.

[0022] Furthermore, in the dyeing process of the above-mentioned special yarn, in S6, the double fixation specifically includes the following contents: first performing a primary fixation, then performing a secondary fixation, and then fully washing to neutrality; wherein, the primary fixation adopts a rare earth-based fixation solution, the rare earth-based fixation solution includes 1~3% owf cerium nitrate and 0.5~1% owf citric acid, and is treated at room temperature for 10~15 minutes; then, without discharging the rare earth-based fixation solution, 1.5~2.5% owf of a reactive cationic polymer fixing agent is added, acetic acid is used to adjust the pH to 5.0~5.5, the temperature is raised to 50~60°C, and the operation is carried out for 20~40 minutes.

[0023] The dual-fixing system utilizes a synergistic mechanism of "rare earth chelation + cationic polymer crosslinking / film formation." Rare earth ions (Ce³⁺) form strong chelates with dye anions. Reactive cationic polymers effectively adsorb to the negatively charged fiber / dye surface under acidic conditions. Through intermolecular forces, film formation, and possible crosslinking reactions, they strongly enclose the dye. This dual action significantly improves color fastness to wet abrasion, alkali, and washing. Thorough washing to neutral water removes excess fixing agent, ensuring yarn quality.

[0024] Furthermore, in the dyeing process of the above-mentioned special yarn, in S7, the neutralization specifically includes the following contents: first performing a neutralization, and then performing a secondary neutralization; wherein, the treatment liquid for the primary neutralization includes 1~3g / L acetic acid and 1~3g / L sodium acetate, the temperature is 30~40°C, and the treatment time is 5~15min; the treatment liquid for the secondary neutralization includes 1~3g / L citric acid and 0.5~1g / L sodium bicarbonate, the temperature is 25~35°C, and the treatment time is 10~20min.

[0025] The neutralization process is divided into primary and secondary neutralization, using different treatment solutions and process parameters. The primary neutralization uses acetic acid and sodium acetate to adjust the yarn's pH, while the secondary neutralization uses citric acid and sodium bicarbonate to further fine-tune the pH, bringing the yarn's pH to the appropriate range. This facilitates subsequent softening and ensures yarn quality.

[0026] Furthermore, in the dyeing process of the above-mentioned special yarn, in S8, the soft finishing specifically includes the following contents: using a two-immersion and two-rolling method with a rolling rate of 70~80%, and then baking, and the baking conditions are 100~110°C for 2~5min; wherein, the soft finishing liquid includes 3~5% owf epoxy-modified amino silicone oil and 0.5~1% owf polyether-modified silicone oil.

[0027] The softening finish utilizes a two-dip, two-pad method and specific baking conditions. The softening solution contains epoxy-modified amino silicone oil, polyether-modified silicone oil, and nano-zinc oxide dispersion. These ingredients impart a soft feel to the yarn. Appropriate padding ratios and baking conditions ensure that the softening agent adheres evenly to the yarn, achieving optimal results.

[0028] The present invention also relates to the application of a dyeing process for special yarns, which can be applied to dyeing of, but not limited to, long-staple cotton high-count yarns, functional fiber blended yarns, medical antibacterial yarns, and high-elastic core-spun yarns, and can give full play to the advantages of the dyeing process and improve the dyeing quality and performance of the yarns.

[0029] Preferably, it is applied to long-staple cotton high-count yarn.

[0030] Compared with the prior art, the present invention has the following beneficial effects: (1) The dyeing process of the special yarn disclosed in the present invention is rationally designed and covers the complete process flow of special yarn dyeing. It starts with singeing to remove the fluff on the yarn surface, making the yarn surface smoother and reducing the pilling phenomenon in subsequent processing. Then, the yarn is shaken to arrange the yarn into a suitable twisted shape, which is convenient for the operation of subsequent processes. The synergistic modification of mercerization improves the dye uptake and fixation rate of the dye and improves the surface properties of the fiber. The scouring and bleaching remove impurities and natural pigments in the yarn, providing a good foundation for dyeing. The dyeing gives the yarn the desired color. The double fixation system significantly improves the color fastness to wet wear, alkali and washing, neutralizes and adjusts the pH value of the yarn, and softens the yarn to give it a soft feel. Drying, rewinding and inspection and packaging ensure the quality of the yarn and facilitate storage and transportation. (2) The dyeing process of the special yarn disclosed in the present invention introduces a fiber reactive modifier in the mercerizing pre-bulking stage. The pre-bulking liquid promotes the initial swelling of the fiber and the penetration of the fiber reactive modifier. The fiber reactive modifier is hydrolyzed under weak alkaline conditions. Its epoxy group can chemically bond with the cellulose hydroxyl group and the dye reactive group during the subsequent concentrated alkali mercerizing and dyeing process. This significantly improves the dye uptake and fixation rate of the dye, reduces the generation of hydrolyzed dyes, improves the fiber surface properties, reduces the surface energy / friction coefficient, and fundamentally improves the color fastness, especially the wet friction and dyeing uniformity. (3) The dyeing process of the special yarn disclosed in the present invention solves the limitation of a single fixing agent and adopts the synergistic mechanism of "rare earth chelation + cationic polymer crosslinking / film formation". The rare earth ions and dye anions form a strong chelate, and the reactive cationic polymer is effectively adsorbed on the negatively charged fiber / dye surface under acidic conditions. Through intermolecular forces, film formation and possible crosslinking reactions, the dye is strongly blocked. The dual action significantly improves the color fastness to wet abrasion, alkali resistance and washing. (4) The application of the dyeing process for special yarns disclosed in the present invention can give full play to its advantages, dyeing according to the characteristics of different yarns, and improving the dyeing quality and performance of the yarns. DETAILED DESCRIPTION

[0031] The following Example 1 and Comparative Examples 1 to 3 are combined with specific experimental data to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise specified, the materials, methods and equipment used in the embodiments of the present invention are conventional materials, methods and equipment in this technical field.

[0032] Example 1 and Comparative Examples 1-3 provide a dyeing process for a special yarn.

[0033] Example 1 Example 1 is 80s / 2 long-staple cotton yarn, and its dyeing process includes the following steps: S1: Singe 80s / 2 long-staple cotton yarn using a gas singeing machine. Process parameters are as follows: flame intensity of propane / air mixture ratio of 1:8 and blue flame height of 30-35mm; burner temperature of 980±20℃; treatment time of single-side contact time of 0.6-0.8s; cooling method of water-cooled rollers to reduce the surface temperature to below 50℃; after singeing, the quality indicators are singeing grade ≥4 (GB / T 4802.1 standard) and fiber weight loss rate ≤0.3%; S2: The yarn is then reeled in using a reeling machine with the following process parameters: yarn frame circumference of 1.8 m, single twist weight of 480 ± 5 gg, and reeling tension of 0.12 ± 0.02 cN / dtex; S3: mercerization synergistic modification is then performed; S31: First, immerse the fiber in 150g / L pre-expanding liquid NaOH at 40°C, add 2.2% owf of fiber reactive modifier KH-560, and immerse for 30 seconds. The fiber is initially expanded at a relatively low alkali concentration to facilitate the penetration of KH-560. KH-560 hydrolyzes under weak alkaline conditions, and its epoxy groups can react with cellulose hydroxyl groups or subsequent dye-reactive groups, thereby increasing dye uptake and fixation rates and improving fiber surface properties. S32: drain the pre-swelling liquid NaOH, and immediately immerse the yarn in 265 g / L NaOH at room temperature for 120 seconds to fully mercerize and swell in the presence of KH-560; S33: squeeze for 60 seconds, then rinse with 80g / L NaOH at 65±5℃ for 60-90 seconds, then rinse with cold water, and finally soak in cold water for later use; S4: Scouring and bleaching are then performed, first with enzyme scouring and then with hydrogen peroxide bleaching; wherein the enzyme scouring uses 0.5% owf alkaline pectate lyase, and the treatment conditions are: pH 9, 50°C, and 60 min; the hydrogen peroxide bleaching solution includes 8g / L hydrogen peroxide, 0.6 / L stabilizer EDDHA, and 0.2% owf sodium polyaspartate, and the treatment temperature is 98°C ± 1°C for 40 min. The termination of hydrogen peroxide bleaching is determined when the redox potential of the monitored solution is ≥ 450mV; S5: Dyeing is then performed using the following formula: Reactive Red HE3B 2.5% owf, Navy Blue HERD 4.0% owf, Yellow HE4R 1.2% owf, Sodium Sulfate 70g / L, Soda Ash 25g / L. After dyeing, the fabric is first washed with room temperature water for 5 min each time. The fabric is then acid washed with 1.5g / L acetic acid at 40°C for 10 min. The fabric is then enzyme washed with 1.0g / L protease at a pH of 5.5-6.0 at 50°C for 15-20 min. The fabric is then washed with hot water at 70-80°C for 15 min. S6: Double fixation is then carried out, with a primary fixation followed by a secondary fixation, followed by thorough water washing until neutrality. A rare earth-based fixation solution is used for the primary fixation, which includes 2.5% owf cerium nitrate and 0.5% owf citric acid. The solution is treated at room temperature for 15 minutes, and the rare earth ions form a stable chelate with the sulfonic acid group of the dye. The rare earth-based fixation solution is not discharged, and 2.0% owf of the fixative DFRF-1S is added. The pH is adjusted to 5.0-5.5 with acetic acid, and the temperature is raised to 55°C. The process is run for 30 minutes, and the fixative DFRF-1S forms a film on the fiber surface and cross-links with the fiber / dye to block the dye. The acidic conditions are conducive to the adsorption of the cationic agent, which synergizes with the rare earth-based fixative. S7: Neutralization is then performed; a primary neutralization is performed first, followed by a secondary neutralization; wherein the primary neutralization treatment solution includes 2 g / L acetic acid and 1 g / L sodium acetate, the temperature is 40°C, the treatment time is 10 minutes, and the surface alkali is quickly neutralized; the secondary neutralization treatment solution includes 1 g / L citric acid and 0.5 g / L sodium bicarbonate, the temperature is 30°C, the treatment time is 15 minutes, and the pH inside the fiber is deeply adjusted; S8: Softening and finishing is then performed using a two-dip, two-pad method with a padding ratio of 75%, followed by baking at 110°C for 3 minutes (hot air circulation). The softening and finishing solution includes 3.5% owf epoxy-modified amino silicone oil (particle size ≤ 80 nm) and 0.7% owf polyether-modified silicone oil. S9: Then drying and reeling are carried out, and finally the packaging is inspected to obtain the 80s / 2 long-staple cotton yarn (navy blue) of Example 1.

[0034] The 80s / 2 long-staple cotton yarn (navy blue) prepared in Example 1 was tested. The test results are shown in Table 1.

[0035] Table 1 Comparative Example 1 Comparative Example 1 is 80s / 2 long-staple cotton yarn, and its dyeing process includes the following steps: S1: Singe 80s / 2 long-staple cotton yarn using a gas singeing machine. Process parameters are as follows: flame intensity of propane / air mixture ratio of 1:8 and blue flame height of 30-35mm; burner temperature of 980±20℃; treatment time of single-side contact time of 0.6-0.8s; cooling method of water-cooled rollers to reduce the surface temperature to below 50℃; after singeing, the quality indicators are singeing grade ≥4 (GB / T 4802.1 standard) and fiber weight loss rate ≤0.3%; S2: The yarn is then reeled in using a reeling machine with the following process parameters: yarn frame circumference of 1.8 m, single twist weight of 480 ± 5 gg, and reeling tension of 0.12 ± 0.02 cN / dtex; S3: mercerize and immerse in 265g / L NaOH for 150s; squeeze for 60s, then rinse with 80g / L NaOH at 65±5℃ for 60-90s, then rinse with cold water, and finally immerse in cold water for later use; S4: Scouring and bleaching are then performed, first with enzyme scouring and then with hydrogen peroxide bleaching; wherein the enzyme scouring uses 0.5% owf alkaline pectate lyase, and the treatment conditions are: pH 9, 50°C, and 60 min; the hydrogen peroxide bleaching solution includes 8g / L hydrogen peroxide, 0.6 / L stabilizer EDDHA, and 0.2% owf sodium polyaspartate, and the treatment temperature is 98°C ± 1°C for 40 min. The termination of hydrogen peroxide bleaching is determined when the redox potential of the monitored solution is ≥ 450mV; S5: Dyeing is then performed using the following formula: Reactive Red HE3B 2.5% owf, Navy Blue HERD 4.0% owf, Yellow HE4R 1.2% owf, Sodium Sulfate 70g / L, Soda Ash 25g / L. After dyeing, the fabric is first washed with room temperature water for 5 min each time. The fabric is then acid washed with 1.5g / L acetic acid at 40°C for 10 min. The fabric is then enzyme washed with 1.0g / L protease at a pH of 5.5-6.0 at 50°C for 15-20 min. The fabric is then washed with hot water at 70-80°C for 15 min. S6: Then fix the color by adding 2.0% owf of the color fixing agent DFRF-1S, adjusting the pH to 5.0-5.5 with acetic acid, raising the temperature to 55°C, and running for 30 minutes; S7: Neutralization is then performed; a primary neutralization is performed first, followed by a secondary neutralization; wherein the primary neutralization treatment solution includes 2 g / L acetic acid and 1 g / L sodium acetate, the temperature is 40°C, the treatment time is 10 minutes, and the surface alkali is quickly neutralized; the secondary neutralization treatment solution includes 1 g / L citric acid and 0.5 g / L sodium bicarbonate, the temperature is 30°C, the treatment time is 15 minutes, and the pH inside the fiber is deeply adjusted; S8: Softening and finishing is then performed using a two-dip, two-pad method with a padding ratio of 75%, followed by baking at 110°C for 3 minutes (hot air circulation). The softening and finishing solution includes 3.5% owf epoxy-modified amino silicone oil (particle size ≤ 80 nm) and 0.7% owf polyether-modified silicone oil. S9: Then drying and reeling are carried out, and finally the packaging is inspected to obtain the 80s / 2 long-staple cotton yarn (navy blue) of Comparative Example 1.

[0036] In Comparative Example 1, the mercerizing step did not include a pre-bulking stage and no fiber-reactive modifier was added. A single fixing agent was used in the color fixing step. Other conditions were the same as in Example 1. The 80s / 2 long-staple cotton yarn (navy blue) produced in Comparative Example 1 was tested, and the test results are shown in Table 2.

[0037] Table 2 Comparative Example 2 Comparative Example 2 is 80s / 2 long-staple cotton yarn, and its dyeing process includes the following steps: S1: Singe 80s / 2 long-staple cotton yarn using a gas singeing machine. Process parameters are as follows: flame intensity of propane / air mixture ratio of 1:8 and blue flame height of 30-35mm; burner temperature of 980±20℃; treatment time of single-side contact time of 0.6-0.8s; cooling method of water-cooled rollers to reduce the surface temperature to below 50℃; after singeing, the quality indicators are singeing grade ≥4 (GB / T 4802.1 standard) and fiber weight loss rate ≤0.3%; S2: The yarn is then reeled in using a reeling machine with the following process parameters: yarn frame circumference of 1.8 m, single twist weight of 480 ± 5 gg, and reeling tension of 0.12 ± 0.02 cN / dtex; S3: mercerize and immerse in 265g / L NaOH for 150s; squeeze for 60s, then rinse with 80g / L NaOH at 65±5℃ for 60-90s, then rinse with cold water, and finally immerse in cold water for later use; S4: Scouring and bleaching are then performed, first with enzyme scouring and then with hydrogen peroxide bleaching; wherein the enzyme scouring uses 0.5% owf alkaline pectate lyase, and the treatment conditions are: pH 9, 50°C, and 60 min; the hydrogen peroxide bleaching solution includes 8g / L hydrogen peroxide, 0.6 / L stabilizer EDDHA, and 0.2% owf sodium polyaspartate, and the treatment temperature is 98°C ± 1°C for 40 min. The termination of hydrogen peroxide bleaching is determined when the redox potential of the monitored solution is ≥ 450mV; S5: Dyeing is then performed using the following formula: Reactive Red HE3B 2.5% owf, Navy Blue HERD 4.0% owf, Yellow HE4R 1.2% owf, Sodium Sulfate 70g / L, Soda Ash 25g / L. After dyeing, the fabric is first washed with room temperature water for 5 min each time. The fabric is then acid washed with 1.5g / L acetic acid at 40°C for 10 min. The fabric is then enzyme washed with 1.0g / L protease at a pH of 5.5-6.0 at 50°C for 15-20 min. The fabric is then washed with hot water at 70-80°C for 15 min. S6: Double fixation is then carried out, with a primary fixation followed by a secondary fixation, followed by thorough water washing until neutrality. A rare earth-based fixation solution is used for the primary fixation, which includes 2.5% owf cerium nitrate and 0.5% owf citric acid. The solution is treated at room temperature for 15 minutes, and the rare earth ions form a stable chelate with the sulfonic acid group of the dye. The rare earth-based fixation solution is not discharged, and 2.0% owf of the fixative DFRF-1S is added. The pH is adjusted to 5.0-5.5 with acetic acid, and the temperature is raised to 55°C. The process is run for 30 minutes, and the fixative DFRF-1S forms a film on the fiber surface and cross-links with the fiber / dye to block the dye. The acidic conditions are conducive to the adsorption of the cationic agent, which synergizes with the rare earth-based fixative. S7: Neutralization is then performed; a primary neutralization is performed first, followed by a secondary neutralization; wherein the primary neutralization treatment solution includes 2 g / L acetic acid and 1 g / L sodium acetate, the temperature is 40°C, the treatment time is 10 minutes, and the surface alkali is quickly neutralized; the secondary neutralization treatment solution includes 1 g / L citric acid and 0.5 g / L sodium bicarbonate, the temperature is 30°C, the treatment time is 15 minutes, and the pH inside the fiber is deeply adjusted; S8: Softening and finishing is then performed using a two-dip, two-pad method with a padding ratio of 75%, followed by baking at 110°C for 3 minutes (hot air circulation). The softening and finishing solution includes 3.5% owf epoxy-modified amino silicone oil (particle size ≤ 80 nm) and 0.7% owf polyether-modified silicone oil. S9: Then drying and reeling are carried out, and finally the packaging is inspected to obtain the 80s / 2 long-staple cotton yarn (navy blue) of Comparative Example 2.

[0038] The mercerizing step of Comparative Example 2 does not include a pre-bulking stage and does not add a fiber reactive modifier, and the rest is the same as in Example 1. The 80s / 2 long-staple cotton yarn (navy blue) prepared in Comparative Example 2 was tested, and the test results are shown in Table 3.

[0039] Table 3 Comparative Example 3 Comparative Example 3 is 80s / 2 long-staple cotton yarn, and its dyeing process includes the following steps: S1: Singe 80s / 2 long-staple cotton yarn using a gas singeing machine. Process parameters are as follows: flame intensity of propane / air mixture ratio of 1:8 and blue flame height of 30-35mm; burner temperature of 980±20℃; treatment time of single-side contact time of 0.6-0.8s; cooling method of water-cooled rollers to reduce the surface temperature to below 50℃; after singeing, the quality indicators are singeing grade ≥4 (GB / T 4802.1 standard) and fiber weight loss rate ≤0.3%; S2: The yarn is then reeled in using a reeling machine with the following process parameters: yarn frame circumference of 1.8 m, single twist weight of 480 ± 5 gg, and reeling tension of 0.12 ± 0.02 cN / dtex; S3: mercerization synergistic modification is then performed; S31: First, immerse the fiber in 150g / L pre-expanding liquid NaOH at 40°C, add 2.2% owf of fiber reactive modifier KH-560, and immerse for 30 seconds. The fiber is initially expanded at a relatively low alkali concentration to facilitate the penetration of KH-560. KH-560 hydrolyzes under weak alkaline conditions, and its epoxy groups can react with cellulose hydroxyl groups or subsequent dye-reactive groups, thereby increasing dye uptake and fixation rates and improving fiber surface properties. S32: drain the pre-swelling liquid NaOH, and immediately immerse the yarn in 265 g / L NaOH at room temperature for 120 seconds to fully mercerize and swell in the presence of KH-560; S33: squeeze for 60 seconds, then rinse with 80g / L NaOH at 65±5℃ for 60-90 seconds, then rinse with cold water, and finally soak in cold water for later use; S4: Scouring and bleaching are then performed, first with enzyme scouring and then with hydrogen peroxide bleaching; wherein the enzyme scouring uses 0.5% owf alkaline pectate lyase, and the treatment conditions are: pH 9, 50°C, and 60 min; the hydrogen peroxide bleaching solution includes 8g / L hydrogen peroxide, 0.6 / L stabilizer EDDHA, and 0.2% owf sodium polyaspartate, and the treatment temperature is 98°C ± 1°C for 40 min. The termination of hydrogen peroxide bleaching is determined when the redox potential of the monitored solution is ≥ 450mV; S5: Dyeing is then performed using the following formula: Reactive Red HE3B 2.5% owf, Navy Blue HERD 4.0% owf, Yellow HE4R 1.2% owf, Sodium Sulfate 70g / L, Soda Ash 25g / L. After dyeing, the fabric is first washed with room temperature water for 5 min each time. The fabric is then acid washed with 1.5g / L acetic acid at 40°C for 10 min. The fabric is then enzyme washed with 1.0g / L protease at a pH of 5.5-6.0 at 50°C for 15-20 min. The fabric is then washed with hot water at 70-80°C for 15 min. S6: Then fix the color by adding 2.0% owf of the color fixing agent DFRF-1S, adjusting the pH to 5.0-5.5 with acetic acid, raising the temperature to 55°C, and running for 30 minutes; S7: Neutralization is then performed; a primary neutralization is performed first, followed by a secondary neutralization; wherein the primary neutralization treatment solution includes 2 g / L acetic acid and 1 g / L sodium acetate, the temperature is 40°C, the treatment time is 10 minutes, and the surface alkali is quickly neutralized; the secondary neutralization treatment solution includes 1 g / L citric acid and 0.5 g / L sodium bicarbonate, the temperature is 30°C, the treatment time is 15 minutes, and the pH inside the fiber is deeply adjusted; S8: Softening and finishing is then performed using a two-dip, two-pad method with a padding ratio of 75%, followed by baking at 110°C for 3 minutes (hot air circulation). The softening and finishing solution includes 3.5% owf epoxy-modified amino silicone oil (particle size ≤ 80 nm) and 0.7% owf polyether-modified silicone oil. S9: Then drying and reeling are carried out, and finally testing and packaging are carried out to obtain the 80s / 2 long-staple cotton yarn (navy blue) of Comparative Example 3.

[0040] The color fixing step of Comparative Example 3 uses a single color fixing agent, and the rest is the same as in Example 1. The 80s / 2 long-staple cotton yarn (navy blue) prepared in Comparative Example 3 was tested, and the test results are shown in Table 4.

[0041] Table 4 In summary, by adopting the technical solution of the present invention, a fiber reactive modifier is introduced during the mercerizing pre-bulking stage, and the synergistic effect of the pre-bulking liquid and the fiber reactive modifier significantly improves the dyeing effect and fiber performance. The synergistic mechanism of rare earth chelation + cationic polymer cross-linking / film formation is adopted to overcome the limitations of a single fixing agent. Through the dual effects of rare earth ions and reactive cationic polymers, the fabric's wet abrasion resistance, alkali resistance, and wash color fastness are significantly improved. Starting from the pre-dyeing treatment and color fixing links, the present invention effectively improves the problems existing in the traditional dyeing process, provides a new solution for improving dyeing quality and color fastness, and has broad application prospects in the textile printing and dyeing industry.

[0042] The present invention has many specific application paths, and the above is only a preferred embodiment of the present invention. It should be noted that the above embodiments are only used to illustrate the present invention and are not intended to limit the scope of protection of the present invention. For those skilled in the art, several improvements can be made without departing from the principles of the present invention, and these improvements should also be considered as the scope of protection of the present invention.

Claims

1. A dyeing process for special yarns, characterized in that: The steps include: S1: singeing the yarn; S2: The yarn is then reeled; S3: The yarn is then subjected to mercerization synergistic modification; the mercerization synergistic modification refers to adding a fiber reactive modifier during the alkali stage of the mercerization process; S4: The yarn is then scour and bleached; S5: The yarn is then dyed; S6: The yarn is then subjected to double color fixing, wherein the double color fixing refers to sequentially treating the yarn with a rare earth-based color fixing agent and a cationic polymer color fixing agent; S7: The yarn is then neutralized; S8: The yarn is then subjected to a softening finishing process; S9: The yarn is then dried, reeled, and finally inspected and packaged.

2. The dyeing process of special yarn according to claim 1, characterized in that: In S1, the singeing is performed using a gas singeing machine, and the process parameters are: flame intensity is a propane / air mixture ratio of 1: (5-10) and a blue flame height of 30-40 mm; the burner temperature is 900-1100° C.; the treatment time is a single-side contact time of 0.5-1.0 s; the cooling method is a water-cooled roller, and the surface temperature is reduced to below 50° C.

3. The dyeing process of special yarn according to claim 1, characterized in that: In S2, the yarn is reeled using a reeling machine, and the process parameters are: the yarn frame circumference is 1-2 m, the single twist weight is 400-500 g, and the reeling tension is 0.1-0.2 cN / dtex.

4. The dyeing process of special yarn according to claim 1, characterized in that: In said S3, mercerization synergistic modification specifically includes the following contents: S31: Immerse the yarn in 120-150 g / L pre-expanded NaOH at 35-40°C, add 1.5-3.0% owf of fiber reactive modifier KH-560, and immerse for 30-60 seconds; S32: drain the pre-swelling liquid NaOH, and immediately immerse the yarn in 250-260 g / L NaOH at room temperature for 90-150 seconds to fully mercerize and swell in the presence of fiber reactive modifier KH-560; S33: Squeeze and then rinse with 80-100 g / L NaOH at 60-70°C for 60-100 seconds, then rinse with cold water, and finally soak in cold water for later use.

5. The dyeing process of special yarn according to claim 1, characterized in that: In S4, scouring and bleaching specifically include the following: first performing enzyme scouring, and then performing hydrogen peroxide bleaching; wherein, the enzyme scouring uses 0.5-1% owf alkaline pectate lyase, and the treatment conditions are: pH 8-9, 40-50°C, and 40-60 min; the hydrogen peroxide bleaching solution includes 8-10 g / L hydrogen peroxide, 0.5-1 g / L stabilizer EDDHA, and an added amount of 0.1-0.5% owf sodium polyaspartate, the treatment temperature is 90-100°C, and the treatment time is 30-60 min. The termination of hydrogen peroxide bleaching is judged by monitoring the solution redox potential to be ≥450 mV.

6. The dyeing process of special yarn according to claim 1, characterized in that: In the S5, dyeing specifically includes the following contents: dyeing the yarn, and first washing it with water at room temperature after dyeing for 5 to 10 minutes; then pickling it with 1 to 2 g / L acetic acid at a temperature of 30 to 40°C for 5 to 10 minutes; then washing it with a biological enzyme at a pH of 5.5 to 6.0, at a temperature of 40 to 50°C, for 15 to 20 minutes; and then washing it with hot water at a temperature of 70 to 80°C for 15 to 20 minutes.

7. The dyeing process of special yarn according to claim 1, characterized in that: In S6, the double color fixation specifically includes the following contents: first performing a color fixation, then performing a secondary color fixation, and then fully washing with water to neutrality; wherein, the primary color fixation uses a rare earth-based color fixation solution, the rare earth-based color fixation solution includes 1-3% owf cerium nitrate and 0.5-1% owf citric acid, and the treatment is carried out at room temperature for 10-15 minutes; then, without discharging the rare earth-based color fixation solution, 1.5-2.5% owf of a reactive cationic polymer color fixative is added, acetic acid is used to adjust the pH to 5.0-5.5, the temperature is raised to 50-60°C, and the process is run for 20-40 minutes.

8. The dyeing process of special yarn according to claim 1, characterized in that: In S7, the neutralization specifically includes the following contents: first performing a primary neutralization and then performing a secondary neutralization; wherein the treatment liquid for the primary neutralization includes 1-3 g / L acetic acid and 1-3 g / L sodium acetate, the temperature is 30-40°C, and the treatment time is 5-15 min; the treatment liquid for the secondary neutralization includes 1-3 g / L citric acid and 0.5-1 g / L sodium bicarbonate, the temperature is 25-35°C, and the treatment time is 10-20 min.

9. The dyeing process of special yarn according to claim 1, characterized in that: In S8, the softening finishing specifically includes the following contents: adopting a two-immersion and two-rolling method with a rolling rate of 70-80%, and then baking, and the baking conditions are 100-110°C for 2-5 minutes; wherein the softening finishing liquid includes 3-5% owf epoxy-modified amino silicone oil and 0.5-1% owf polyether-modified silicone oil.

10. The dyeing process for special yarn according to any one of claims 1 to 9, characterized in that: It is used in dyeing of long-staple cotton high-count yarn, functional fiber blended yarn, medical antibacterial yarn, and high-elastic core-spun yarn, which can give full play to the advantages of the dyeing process and improve the dyeing quality and performance of the yarn.

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