Tension-free antifibrillating dyeing method of lyocell blended yarn

Abstract

The invention belongs to the technical field of textile dyeing methods, and particularly relates to a tension-free anti-fibrillation dyeing method for lyocell blended yarn. The tension-free fibrillating-resistant dyeing method of the lyocell blended yarn comprises the following steps: preparing a bobbin-free loose yarn bundle, namely loosely winding lyocell pure spinning or blended yarn into tension-free yarn bundles of which the weight is 0.5-1.5 kg by adopting an integrated chuck bobbin, and meanwhile, wrapping the tension-free yarn bundles with knitted sock legs; according to the tension-free loose yarn bundle filling, a cross-shaped lifting chain is matched with a yarn bundle grate, staggered filling shaped like a Chinese character'pin 'is achieved, and the loading rate ranges from 90% to 120%. The tension-free one-bath dyeing / cross-linking comprises the following steps: pre-treating the filled tension-free loose yarn bundle, performing dyeing and cross-linking through a one-bath two-step method, and finally performing soaping, hot water washing, color fixation / softening one-bath treatment and radio frequency drying. According to the tension-free antifibrillating dyeing method for the lyocell blended yarn, dyeing is uniform, the color difference is small, and the percent of pass is increased.

Description

Technical Field

[0001] This invention belongs to the technical field of textile dyeing methods, specifically relating to a tension-free antigen-fibrillation dyeing method for lyocell blended yarns. Background Technology

[0002] Currently, lyocell fiber, a green regenerated cellulose fiber derived from natural renewable wood, produced through an environmentally friendly process with biodegradable waste, has become a highly sought-after raw material in the high-end shirt and underwear market due to its excellent moisture absorption and breathability, high strength, and soft, comfortable feel. However, the large-scale application of lyocell fiber in yarn-dyed fabric production has long been severely constrained by two inherent technical challenges. The first is the fibrillation problem. Due to the highly oriented molecular structure of the fiber, the lateral connections between surface microfibrils are prone to breakage when wet or subjected to friction, forming microfibrils with diameters of only tens of nanometers. This phenomenon directly leads to "frosty" white fuzz, hazy dullness, and "shadowy" patterns in yarn-dyed fabrics during wear and washing, accompanied by problems such as itching, pilling, and decreased dimensional stability. The second is the color difference problem during dyeing. Traditional package dyeing methods commonly suffer from color differences between inner and outer layers and between packages due to factors such as deformation from repeated use of resin bobbins, variations in yarn winding density, and uneven dye penetration. Industry standards are typically only at level 3-4, as seen in the package dyeing method disclosed in CN115058006A. This process results in a low first-pass yield, increases rework costs and energy consumption, and makes it difficult to meet the stringent color uniformity requirements of the high-end market.

[0003] To address these challenges, existing technologies often seek breakthroughs from a single perspective. Regarding fibrillation, the mainstream chemical crosslinking method, particularly the dyeing-in-the-bath crosslinking process, while short and energy-efficient, faces the challenge of competitive dyeing due to the competition between reactive dyes and crosslinking agents for hydroxyl reaction sites on the fiber. This directly leads to a significant decrease in dye uptake and color depth. Although some studies have proposed optimizing to a two-step method to alleviate competitive dyeing, this requires extremely high process control. While post-dyeing separate-bath crosslinking can avoid competitive dyeing, it increases the number of steps and energy consumption, and may cause greater strength damage. Regarding color difference in dyeing, some innovations have proposed using bobbin-less yarn dyeing devices and processes to optimize dye liquor flow and achieve uniform dyeing. However, these primarily focus on solving color differences and do not integrate fibrillation treatment, nor address the competitive dyeing conflict during co-bath treatment. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a tension-free antigen-fibrillated dyeing method for lyocell blended yarns, which results in uniform dyeing, small color difference, and increased pass rate.

[0005] The method for tension-free antigen fibrillation dyeing of the Lyocell blended yarn according to the present invention includes the following steps: preparation of tension-free bobbinless loose yarn bundles, loading of tension-free loose yarn bundles, and tension-free one-bath dyeing / crosslinking; The preparation of the tension-free bobbinless loose yarn bundles uses an integral chuck bobbin to wind the pure Lyocell or blended yarn into tension-free yarn bundles of 0.5 - 1.5 kg each, while wrapping them with knitted sock tubes to prevent them from being scattered; For the loading of the tension-free loose yarn bundles, a cross hanging chain is used in combination with a yarn bundle grate to achieve staggered loading in a "pin" shape, and the loading rate is 90% - 120%; The tension-free one-bath dyeing / crosslinking is to subject the loaded tension-free loose yarn bundles to pretreatment and then achieve dyeing crosslinking through a two-step one-bath method, which can overcome the problem of a significant decrease in the fiber color depth caused by the competing dyeing of the dye and the crosslinking agent in the same bath. Finally, it undergoes soaping, hot water washing, one-bath treatment of fixing / softening, and radio frequency drying.

[0006] The pure Lyocell or blended yarn contains at least one of cotton, hemp, wool, silk, or other natural fibers in its blended components, and the content of Lyocell fibers in the blended components is 50 wt% or more.

[0007] The knitted sock tube is made of polyester or nylon, has good elasticity, and since reactive dyes cannot color it, the knitted sock tube can be reused.

[0008] The staggered loading in a "pin" shape means that the yarn bundles are arranged alternately in the upper, middle, and lower layers in the dyeing cage, and adjacent yarn bundles are closely arranged to ensure no flow loss when the dyeing solution flows between the yarn bundles.

[0009] For the tension-free one-bath dyeing / crosslinking, the loaded tension-free loose yarn bundles are pretreated. The working solution formula for the pretreatment is: 2 - 4 g / L of scouring agent, 0 - 2 g / L of caustic soda, 0 - 1 g / L of chelating agent, 0 - 6 g / L of hydrogen peroxide, 0.5 - 1.5 g / L of degreasing agent, the treatment temperature is 100 - 110 °C, and the heat preservation time is 20 - 50 min.

[0010] The scouring agent is a non-ionic or anionic fatty alcohol polyoxyethylene ether compound, and the degreasing agent is a non-ionic or anionic surfactant.

[0011] The specific steps for achieving dyeing crosslinking using the one-bath two-step method are as follows: First, add 10-30 g / L of sodium sulfate at a temperature of 40-50℃. After 10-30 min, add the reactive dye using a linear feeding method. Then, raise the temperature to 55-60℃ at a heating rate of 1-1.5℃ / min. After holding at this temperature for 10-30 min, add 5-10 g / L of soda ash using a linear feeding method. Continue to hold at 55-60℃ for 10-30 min, and then add 2-6 g / L of lyocell crosslinking agent using a linear feeding method. Finally, complete the crosslinking and color fixing for 20-40 min to finish the dyeing crosslinking. The power of the circulating pump is maintained at 80%-90% of the rated power, and no reversing is required throughout the process. The linear feeding method is controlled by the feeding system built into the dyeing machine. It can be controlled by selecting different feeding curves, allowing the reactive dye, soda ash, or crosslinking agent to be injected into the dye bath at a uniform and continuous rate under the set feeding curve. The main purpose is to ensure that the agents are uniformly dispersed in the dye bath in real time, avoiding uneven dyeing or color variations caused by excessively high local concentrations or excessively fast dyeing rates. The concentrations of sodium sulfate, soda ash, and lyocell crosslinking agent are calculated based on the total water volume of the dye bath, i.e., each liter of dye bath water contains 10-30g of sodium sulfate, 5-10g of soda ash, and 2-6g of lyocell crosslinking agent, respectively.

[0012] The reactive dye is one or both of monochlorotriazine and vinyl sulfone, and the amount of reactive dye used is 0.5-6% (owf, i.e., percentage relative to the weight of yarn).

[0013] The soap washing process conditions are: soaping agent 1-3g / L, temperature 80-95℃, time 10-20min; the hot water washing process conditions are: temperature 80-98℃, time 10-15min, 2-3 washes.

[0014] In the one-bath treatment for color fixing / softening, the color fixing agent is a cationic color fixing agent, with a dosage of 1-3 g / L, and the softener is an organosilicon softener or a cationic softener, with a dosage of 2-5 g / L.

[0015] Given that the reaction principle between lyocell crosslinking agents and fibers is the same as that between dyes and lyocell fibers, when the crosslinking agent and dye are added to the dye bath simultaneously, a competitive situation arises, known as "competitive dyeing." The most direct problem caused by competitive dyeing is a decrease in dye utilization, ultimately leading to a reduction in the color depth of the fiber and an increase in dyeing costs. This patent, through an optimized dyeing and crosslinking process, not only achieves the dyeing of lyocell fiber yarns but also effectively prevents fibrillation of lyocell fibers. Furthermore, this process avoids the competitive dyeing problem that may occur when lyocell crosslinking agents and dyes are added simultaneously, thus ensuring an improved color depth of the fiber. This method is simple to operate, cost-controllable, suitable for industrial production, and has broad application prospects.

[0016] Although the present invention uses the integrated chuck bobbin of the soft winding machine in Patent CN119900138A, its "tension-free" dyeing effect is not mainly brought by this equipment alone. Instead, it is through the uniform soft winding basis provided by the equipment, combined with the "pin-shaped" staggered loading process of the present invention (the cross hanging chain and the yarn beam grate achieve a tight arrangement at a loading rate of 90%-120%), and the directional circulation control of 80%-90% of the circulating pump power during the dyeing process that jointly constructs a tension-free physical environment for the yarn beam throughout the dyeing process, thereby achieving uniform penetration of the dye liquor and zero color difference effect. The equipment is only a tool to achieve the basic form, while the specific loading method and process control are the contributions of the present invention in the physical form. The present invention adopts the "one-bath two-step" process to avoid competitive dyeing and maintain a high color yield depth. After adopting this process, its effect is significantly better than the traditional one-bath one-step method: at the same dye dosage, compared with the traditional one-bath one-step method (dyes and crosslinking agents are added simultaneously), the color yield depth is increased. Among them, the slow heating rate, staged heat preservation, and linear gradient feeding of soda ash / crosslinking agent effectively control the reaction priority of dyes and crosslinking agents at different stages, avoiding the direct competition of active groups.

[0017] The tension-free state realizes the fluffiness and uniformity of the yarn beam microstructure through the "pin-shaped" staggered loading, which is more conducive to the uniform penetration of specific crosslinking agents into the fiber interior in the dye bath and the step-by-step reaction with dye molecules at different stages: first, the covalent bond between the dye and the fiber is completed during the heat preservation stage at 60°C, and then the crosslinking fixation between fiber molecular chains is achieved through the addition of subsequent crosslinking agents. The tension-free environment avoids the uneven penetration of agents caused by yarn contraction, and the optimization of process parameters further enhances the mass transfer efficiency of auxiliaries in the tension-free yarn beam. The combined action of the three makes the dyeing uniform, the color yield depth increased, and the anti-fibrillation effect good.

[0018] Compared with the prior art, the beneficial effects of the present invention are: (1) By adopting the tension-free yarn beam technology, the present invention realizes tension-free zero-color-difference dyeing of Lyocell pure spun or blended yarns, ensuring that the color difference between the inner and outer layers and among individuals of the yarn reaches level 5, thus completely eliminating the situation of rework.

[0019] (2) The present invention effectively solves the fibrillation problem of Lyocell pure spun or blended yarns. At the same time, by optimizing and adjusting the process, it avoids the crosslinking and dye competitive dyeing caused by co-bath crosslinking during dyeing, thereby avoiding the situation of decreased color yield depth.

[0020] (3) The loading rate of the tension-free yarn beam dyeing of the present invention can be ≥100%, and the first-pass qualification rate of dyeing is significantly improved, meeting the production requirements of enterprise quality improvement and efficiency increase. For example, through scientific control of the process curve and optimization of process parameters, the energy consumption and wastewater discharge in the dyeing and finishing process are significantly reduced, and the process stability is significantly improved. Description of the Drawings

[0021] Figure 1 The image shows a comparison of the knitted socks in Comparative Example 1 and Example 1 before and after washing (magnification 500). Detailed Implementation

[0022] The present invention will be further described below with reference to specific embodiments.

[0023] All raw materials used in the examples, unless otherwise specified, were commercially available.

[0024] The refining agent is SAELR, the chelating agent is SQBLR, the soaping agent is WO, the softener is LUA, and the color fixing agent is FA-LV, all of which were purchased from Zibo Lurui Fine Chemical Co., Ltd.

[0025] Lyocell crosslinking agent KR-6347 was purchased from Qingdao Kerun Biotechnology Co., Ltd.

[0026] Degreasing agent TF101N and Lyocell interchain locking agent LinkcelFF were purchased from Chuanhua Chemical.

[0027] The mass concentration of hydrogen peroxide is 27.5%.

[0028] The reactive black dye BKSRFN was purchased from Shanghai Annoqi Group Co., Ltd. Reactive Blue BK-HL, Reactive Red RK-3BS, and Reactive Yellow YK-3RS were all purchased from Kyung In Trading Co., Ltd. in South Korea. The dyeing machine mentioned is manufactured and modeled as ALLWIN-90 by Lixin Dyeing and Finishing Machinery (Shenzhen) Co., Ltd. The loose-type winding machine is manufactured and modeled by Swiss company SSM Textile Machinery PWX-W.

[0029] The integrated chuck tube used in the following winding machine is the tube from the published patent CN119900138A.

[0030] Example 1 The tension-free antigen fibrillation staining method for 100% Lyocell yarn includes the following steps: Step 1: Preparation of loose yarn bundles without bobbins Using an integrated clamping tube of a self-developed loose winding machine, 100% Lyocell fiber yarn (30S) is loosely wound into tension-free yarn bundles of 0.6kg each, while being wrapped with polyester knitted sock sleeves to prevent the yarn bundles from scattering.

[0031] Step 2: Tension-free loose yarn bundle filling During dyeing, a cross hanging chain is used in combination with an adjustable yarn beam grate. The yarn beams are arranged in a staggered manner in the upper, middle, and lower layers of the dyeing cage, loaded in a "pin" shape, and adjacent yarn beams are closely arranged to ensure that there is no flow loss when the dye liquor passes through the yarn beams during dyeing. At this time, the loading rate of the tension-free yarn beams is 90%.

[0032] Step 3: Tension-free one-bath dyeing-crosslinking (1) Pretreatment: The working liquor circulates unidirectionally from the inside out. The formula of the working liquor is: 2 g / L of refining agent SAELR and 1.5 g / L of degreasing agent TF101N. The treatment conditions are 105 °C for 30 min.

[0033] (2) Dyeing / crosslinking in one bath in two steps: First, add 20 g / L of sodium sulfate during the linear feeding stage at 45 °C. After 20 min, add 2% of reactive red RK-3BS in a linear feeding manner within 10 min. Then, heat up to 60 °C at a heating rate of 1.5 °C / min and hold for 20 min. After that, add 8 g / L of soda ash in a linear feeding manner within 15 min, continue to hold for 20 min, and then add 6 g / L of Lyocell crosslinking agent KR-6347 in a linear feeding manner within 25 min. Finally, hold for 30 min to complete dyeing and crosslinking; during the dyeing and crosslinking process, the power of the circulation pump remains at 80% of the rated power and does not change direction throughout the process.

[0034] (3) Post-treatment: Soaping, using 2 g / L of soaping agent WO, temperature 90 °C, time 15 min; hot water washing, temperature 98 °C, time 10 min, wash with water twice; fixing-softening in one bath, 2 g / L of fixing agent FA-LV, 3 g / L of softening agent LUA, temperature 55 °C, time 20 min; after the fixing and softening treatment, spin-dry the yarn, and then perform radio frequency drying.

[0035] After the post-treatment, the inner and outer layer difference of the yarn is tested. At the same time, the yarn is woven into a knitted sock tube for subsequent electron microscopy analysis, as Figure 1 shown.

[0036] Example 2 The tension-free anti-fibrillation dyeing method for the Lyocell blended yarn includes the following steps: Step 1: Preparation of tension-free loose yarn beams without bobbin An independently developed integrated chuck bobbin is used to wind the Lyocell / cotton blended yarn (Lyocell accounts for 65%, cotton accounts for 35%, 40S) into tension-free yarn beams of 1.4 kg each in a loose manner, and at the same time, it is wrapped with a nylon knitted sock tube to prevent the yarn beams from being scattered.

[0037] Step 2: Loading of tension-free loose yarn beams During dyeing, a cross hanging chain is used in combination with an adjustable yarn bundle grate. The yarn bundles are arranged alternately in the upper, middle, and lower layers in the dyeing cage, loaded in a "pin" shape, and adjacent yarn bundles are closely arranged to ensure that there is no flow loss when the dye liquor passes through the yarn bundles during dyeing. At this time, the loading rate of the tension-free yarn bundles is 105%.

[0038] Step 3: Tension-free one-bath dyeing-crosslinking (1) Pretreatment: The working liquor adopts a one-way circulation mode from the inside to the outside. Its formula is: 3 g / L of refining agent SAELR, 1 g / L of caustic soda, 6 g / L of hydrogen peroxide, and 1.0 g / L of degreasing agent TF101N. The treatment temperature is 100 °C, and the holding time is 40 min.

[0039] (2) Dyeing-crosslinking in one bath in two steps: In the linear feeding stage at 40 °C, first add 15 g / L of sodium sulfate, add 3%, reactive blue BK-HL and 1% reactive yellow YK-III RS after 15 min, then heat up to 60 °C at a heating rate of 1.5 °C / min. After holding for 15 min, add 6 g / L of soda ash by linear uniform feeding in 15 min. After continuing to hold at 60 °C for 15 min, then adopt the linear feeding method, and uniformly add 2 g / L of lyocell crosslinking agent KR-6347 and 2 g / L of lyocell interchain locking agent Linkcel FF within 15 min, and finally hold for 25 min to complete the dyeing and crosslinking of the yarn. During the dyeing and crosslinking process, the power of the circulation pump remains at 80% of the rated power, and there is no commutation throughout the process.

[0040] (3) Post-treatment: Soaping, using 1.5 g / L of soaping agent WO, temperature 85 °C, time 15 min; hot water washing, temperature 85 °C, time 12 min, washing 3 times; fixing-softening in one bath, using 1.5 g / L of fixing agent FA-LV and 4 g / L of softening agent LUA, temperature 55 °C, time 20 min. After fixing and softening, the yarn is spun dry and then radio frequency dried to test the internal and external color difference of the yarn.

[0041] Example 3 The tension-free anti-fibrillation dyeing method for the lyocell blended yarn includes the following steps: Step 1: Preparation of tension-free loose yarn bundles without bobbin An integrally developed chuck bobbin is used to loosely wind the lyocell / flax blended yarn (70% lyocell, 30% flax, 21S) into tension-free yarn bundles of 1.1 kg each, and at the same time, it is外包 with a polyester knitted sock tube to prevent dispersion.

[0042] Step 2: Loading of tension-free loose yarn bundles During dyeing, a cross hanging chain is used in combination with an adjustable yarn bundle comb, and the yarn bundles are arranged alternately in the upper, middle and lower layers in the dyeing cage, loaded in a "pin" shape, and adjacent yarn bundles are closely arranged to ensure that there is no flow loss when the dye liquor passes through the yarn bundles during dyeing, and the loading rate of the tension-free yarn bundles reaches 115%.

[0043] Step 3: Tension-free one-bath dyeing-crosslinking (1) Pretreatment: The working solution adopts a one-way circulation mode from the inside to the outside. Its formula is 4 g / L refining agent SAELR, 1 g / L chelating agent SQBLR, 2 g / L caustic soda, 6 g / L hydrogen peroxide, and 0.6 g / L degreasing agent TF1***N. The treatment temperature is 110 °C and the treatment time is 45 min.

[0044] (2) One-bath two-step dyeing-crosslinking: In the linear feeding stage at 50 °C, first add 30 g / L of sodium sulfate, then add 6% reactive black BKSRFN, and then heat up to 60 °C at a heating rate of 1.5 °C / min and keep warm for 30 min. After that, add 10 g / L of soda ash by linear feeding in 20 min, continue to keep warm at 60 °C for 30 min, and then use the linear feeding method again to add 4 g / L of Lyocell crosslinking agent KR-6347 in 20 min. Finally, keep warm for 40 min to complete the dyeing crosslinking. During the dyeing crosslinking process, the power of the circulation pump remains at 80% of the rated power, and there is no commutation throughout the process.

[0045] (3) Post-treatment: Soaping, using 3 g / L of soaping agent WO, treating at 95 °C for 20 min; hot water washing, washing at 85 °C for 15 min, washing twice; fixing-softening one-bath, using 3 g / L of fixing agent FA-LV and 5 g / L of softening agent LUA, treating at 55 °C for 20 min. After the fixing and softening treatment, the yarn is spun dry, then radio frequency dried, and then the internal and external color differences of the yarn are tested.

[0046] Comparative Example 1 Using the conventional method, 100% Lyocell fiber yarn (30S) is loosely wound into a cheese yarn of 1.0 kg / each (using a conventional resin bobbin, the density of the cheese yarn is 0.35 g / cm 3 ), and then pretreatment, dyeing and post-treatment are carried out according to the normal cheese yarn process. Specifically, the pretreatment, dyeing (except for not adding the Lyocell crosslinking agent KR-6347, the other steps are the same as those in Example 1), and post-treatment processes of Comparative Example 1 are the same as those in Example 1.

[0047] After the post-treatment, the internal and external layer differences of the yarn dyed in Comparative Example 1 are tested. At the same time, the yarn is woven into a knitted sock tube for subsequent electron microscopy analysis, as Figure 1 shown.

[0048] Comparative Example 1-1 Using conventional methods, 100% Lyocell fiber yarn (30S) is loosely wound into 1.0kg / piece cones (using conventional resin bobbins, cone density 0.35g / cm³). 3 Then, following standard yarn bobbin processing, the yarn undergoes pretreatment, dyeing, and post-treatment. Specifically: (1) Pretreatment: The working solution formula is refining agent SAELR 2g / L and degreasing agent TF101N 1.5g / L. The treatment conditions are 105℃×30min, circulation pump power is 70%, and the forward and reverse rotation is alternated (reversing once every 30min).

[0049] (2) Dyeing process: Add 20 g / L of sodium sulfate at 45℃. After 15 min, add 2% owf of active red RK-3BS and 6 g / L of lyocell crosslinking agent KR-6347 simultaneously through linear feeding (added at a uniform rate within 10 min). Then, raise the temperature to 60℃ at 2℃ / min, keep it at that temperature for 30 min, and add 8 g / L of soda ash at once. Continue to keep it at that temperature for 40 min to complete the dyeing crosslinking. The circulation pump power is 70%, and the forward and reverse rotations are alternated.

[0050] (3) Post-treatment: exactly the same as in Example 1 (soap WO 2g / L, 90℃×15min, hot water wash 98℃×10min×2 times, color fixer FA-LV 2g / L + softener LUA 3g / L, 55℃×20min, spin dry and then radio frequency dry).

[0051] Comparative Examples 1-2 Except for the simultaneous linear addition of the crosslinking agent and dye to the dye liquor during dyeing and crosslinking, all other steps (preparation of loose yarn bundles without bobbins, tension-free filling method, pretreatment and posttreatment processes) are the same as in Example 1. The specific dyeing steps are as follows: (1) Pretreatment: exactly the same as in Example 1 (refining agent SAELR 2g / L, degreasing agent TF101N 1.5g / L, 105℃×30min, circulating pump power 80% unidirectional circulation).

[0052] (2) Dyeing / crosslinking: Add 20 g / L of sodium sulfate at 45℃. After 20 min, add 2% owf of reactive red RK-3BS and 6 g / L of lyocell crosslinking agent KR-6347 simultaneously via linear feeding (added at a uniform rate within 10 min). Then, raise the temperature to 60℃ at 1.5℃ / min and keep it at that temperature for 20 min. After that, add 8 g / L of soda ash via linear feeding (within 15 min). Continue to keep it at that temperature for 20 min and then keep it at that temperature for 30 min to complete the dyeing and crosslinking. The circulation pump power is 80% and the direction is not reversed throughout the process.

[0053] (3) Post-processing: exactly the same as in Example 1.

[0054] Comparative Example 2 Using conventional methods, lyocell / cotton blended yarn (65% lyocell, 35% cotton, 40S) is loosely wound into 1.4kg / piece cones (using conventional resin bobbins, cone density 0.37g / cm³). 3 Then, the yarn was pretreated, dyed, and posttreated according to the normal yarn package process. Specifically, the pretreatment, dyeing (except for the absence of Lyocell crosslinking agent KR-6347 and Lyocell interchain locking agent LinkcelFF, the remaining steps were the same as in Example 2), and posttreatment processes of Comparative Example 2 were all the same as in Example 2. After the posttreatment was completed, the difference between the inner and outer layers of the dyed yarn of Comparative Example 2 was tested.

[0055] Comparative Example 2-1 Using conventional methods, lyocell / cotton blended yarn (65% lyocell, 35% cotton, 40S) is loosely wound into 1.4kg / piece cones (using conventional resin bobbins, cone density 0.37g / cm³). 3 Then, following standard yarn bobbin processing, the yarn undergoes pretreatment, dyeing, and post-treatment. Specifically: (1) Pretreatment: The working solution formula is refining agent SAELR 3g / L, caustic soda 1g / L, hydrogen peroxide 6g / L, degreasing agent TF101N 1.0g / L, treatment temperature 100℃, heat preservation time 40min, circulation pump power 70%, forward and reverse rotation alternating circulation (reversing once every 30min).

[0056] (2) Dyeing process: Add 15g / L of sodium sulfate at 40℃. After 15min, add 3% reactive blue BK-HL, 1% owf reactive yellow YK-3RS, 2g / L Lyocell crosslinking agent KR-6347, and 2g / L Lyocell interchain locking agent LinkcelFF simultaneously via linear feeding (added at a uniform rate within 10min). Then, raise the temperature to 60℃ at 1.5℃ / min, keep it at that temperature for 15min, add 6g / L of soda ash at once, keep it at that temperature for another 15min, and then keep it at that temperature for another 25min to complete the dyeing crosslinking. The circulation pump power is 70%, and the forward and reverse rotations are alternated.

[0057] (3) Post-treatment: exactly the same as in Example 2 (soaping agent WO 1.5g / L, 85℃×15min, hot water wash 85℃×12min×3 times, color fixing agent FA-LV 1.5g / L + softener LUA 4g / L, 55℃×20min, spin dry and then radio frequency dry).

[0058] Comparative Example 2-2 Except for the simultaneous linear addition of the crosslinking agent and dye to the dye liquor during dyeing and crosslinking, all other steps (preparation of loose yarn bundles without bobbins, tension-free filling method, pretreatment and posttreatment processes) are the same as in Example 2. The specific dyeing steps are as follows: (1) Pretreatment: exactly the same as in Example 2 (refining agent SAELR 3g / L, caustic soda 1g / L, hydrogen peroxide 6g / L, degreasing agent TF101N 1.0g / L, 100℃×40min, circulating pump power 80% unidirectional circulation).

[0059] (2) Dyeing / crosslinking: Add 15 g / L of sodium sulfate at 40℃. After 15 min, add 3% reactive blue BK-HL, 1% reactive yellow YK-3RS owf, 2 g / L of Lyocell crosslinking agent KR-6347, and 2 g / L of Lyocell interchain locking agent LinkcelFF simultaneously via linear feeding (added at a uniform rate within 10 min). Then, raise the temperature to 60℃ at 1.5℃ / min and hold for 15 min. After that, add 6 g / L of soda ash via linear feeding (within 15 min). Continue to hold for 15 min and then hold for 25 min to complete the dyeing and crosslinking. The circulation pump power is 80% and the direction is not reversed throughout the process.

[0060] (3) Post-processing: exactly the same as in Example 2.

[0061] Comparative Example 3 Using conventional methods, lyocell / linen blended yarn (70% lyocell, 30% linen, 21S) is loosely wound into 1.1kg / piece cones (using conventional resin bobbins, cone density 0.39g / cm³). 3 Then, the yarn was pretreated, dyed, and post-treated according to the normal yarn package process. Specifically, the pretreatment, dyeing (except for the absence of Lyocell crosslinking agent KR-6347, the other steps were the same as in Example 3), and post-treatment processes of Comparative Example 3 were all the same as in Example 3. After the post-treatment was completed, the difference between the inner and outer layers of the dyed yarn of Comparative Example 3 was tested.

[0062] Comparative Example 3-1 Using conventional methods, lyocell / linen blended yarn (70% lyocell, 30% linen, 21S) is loosely wound into 1.1kg / piece cones (using conventional resin bobbins, cone density 0.39g / cm³). 3 Then, following standard yarn bobbin processing, the yarn undergoes pretreatment, dyeing, and post-treatment. Specifically: (1) Pretreatment: The working solution formula is 4g / L refining agent SAELR, 1g / L chelating agent SQBLR, 2g / L caustic soda, 6g / L hydrogen peroxide, and 0.6g / L degreasing agent TF101N. The treatment temperature is 110℃, the treatment time is 45min, the circulation pump power is 70%, and the forward and reverse rotation is alternated (reversing once every 30min).

[0063] (2) Dyeing process: Add 30g / L sodium sulfate at 50℃, then add 6% reactive black BKSRFN and 4g / L Lyocell crosslinking agent KR-6347 simultaneously via linear feeding (added at a uniform rate within 10min), then raise the temperature to 60℃ at a rate of 1.5℃ / min, hold for 30min, then add 10g / L soda ash at once, hold at 60℃ for another 30min, and then hold for 40min to complete the dyeing crosslinking; the circulation pump power is 70%, and the forward and reverse rotations are alternated.

[0064] (3) Post-treatment: exactly the same as in Example 3 (soap WO3g / L, 95℃×20min, hot water wash 85℃×15min×2 times, color fixer FA-LV 3g / L + softener LUA 5g / L, 55℃×20min, spin dry and then radio frequency dry).

[0065] Comparative Example 3-2 Except for the simultaneous linear addition of the crosslinking agent and dye to the dye liquor during dyeing and crosslinking, all other steps (preparation of loose yarn bundles without bobbins, tension-free filling method, pretreatment and posttreatment processes) are the same as in Example 3. The specific dyeing steps are as follows: (1) Pretreatment: exactly the same as in Example 3 (4 g / L refining agent SAELR, 1 g / L chelating agent SQBLR, 2 g / L caustic soda, 6 g / L hydrogen peroxide, 0.6 g / L degreasing agent TF101N, 110℃×45min, circulating pump power 80% one-way circulation).

[0066] (2) Dyeing / crosslinking: Add 30 g / L sodium sulfate at 50℃, then add 6% reactive black BKSRFN and 4 g / L Lyocell crosslinking agent KR-6347 simultaneously via linear feeding (added at a uniform rate within 10 min), then raise the temperature to 60℃ at a rate of 1.5℃ / min, hold for 30 min, then add 10 g / L soda ash via linear feeding over 20 min, hold at 60℃ for another 30 min, and then hold for another 40 min to complete the dyeing and crosslinking; the circulation pump power is 80%, and there is no reversal throughout the process.

[0067] (3) Post-processing: exactly the same as in Example 3.

[0068] Characterization of internal and external differences: The cross-linked yarn after tension-free dyeing is divided into three layers: outer, middle and inner. Then, it is knitted into socks using a sock knitting machine. The color difference is rated according to GB / T251-1995 "Textiles - Tests for Color Fastness - Assessment of Staining - Gray Scale". The color difference between the inner and outer layers and between socks is rated according to GB / T251-1995 "Textiles - Tests for Color Fastness - Assessment of Staining - Gray Scale".

[0069] The inner and outer layer differences and color strength values ​​of the yarn are shown in Tables 1-3.

[0070] Table 1. Data on the inner and outer layer differences and color strength of yarns in Example 1 and Comparative Examples 1, 1-1 and 1-2.

[0071] Table 2. Data on the inner and outer layer differences and color strength of yarns in Example 2 and Comparative Examples 2, 2-1 and 2-2.

[0072] Table 3. Data on the inner and outer layer differences and color strength of yarns in Example 3 and Comparative Examples 3, 3-1 and 3-2.

[0073] Fibrillation characterization: Knitted socks without cross-linking and those with cross-linking after dyeing were divided into two equal parts. One part was not washed, and the other part was washed 10 times and dried according to GB / T8629-2017 "Home Washing and Drying Procedures for Textile Testing". After washing, scanning electron microscopy analysis was performed on both the original samples (without cross-linking) and the samples after 10 washes, as shown in the attached figures. Figure 1 As shown.

[0074] Data testing and electron microscopy analysis of the above embodiments and comparative examples demonstrate that the tension-free antigen fibrillation dyeing method for pure or blended lyocell yarns provided by this invention achieves a two-step dyeing-crosslinking process in a tension-free state through loose yarn bundle preparation and loading without bobbins. This effectively avoids the color difference between inner and outer layers caused by uneven tension in traditional package dyeing, and also effectively prevents the fibrillation tendency of lyocell fibers during dyeing, finishing, and wear. Furthermore, it solves the problem of reduced fiber color depth caused by the competitive dyeing of lyocell crosslinking agents and dyes when added simultaneously. This method is simple to operate, cost-controllable, suitable for industrial production, and has broad application prospects.

Claims

1. A non-tensioned anti-fibrillation dyeing process for lyocell blended yarns, characterized by: The method comprises the following steps: Tubeless loose yarn bundle preparation, tensionless loose yarn bundle loading, and tensionless one-bath dyeing / crosslinking. The tubeless loose yarn bundle preparation is to use an integrated chuck tube to loosely wind Lyocell pure or blended yarn into each 0.5-1.5 kg tensionless yarn bundle, and meanwhile, the yarn bundle is wrapped with a knitted sock tube. The tensionless loose yarn bundle loading is to use a cross-linking to realize "pin" shape staggered loading, and the loading rate is 90%-120%. The tensionless one-bath dyeing / crosslinking is to realize dyeing and crosslinking through a two-step one-bath method after pretreatment of the loaded tensionless loose yarn bundle, and finally, the yarn bundle is subjected to soaping, hot water washing, and one-bath solidification / softening treatment and radio frequency drying.

2. Tension free anti fibrillation dyeing process of lyocell blended yarn as claimed in claim 1 wherein: The Lyocell pure or blended yarn contains at least one of cotton, hemp, wool, silk or other natural fibers, and the content of Lyocell fiber in the blended yarn is 50wt% or above.

3. The process for tension free anti fibrillation dyeing of lyocell blended yarn as claimed in claim 2 wherein: The knitted sock tube is made of polyester or nylon.

4. The process for tension free anti fibrillation dyeing of lyocell blended yarn as claimed in claim 3 wherein: The "pin" shape staggered loading refers to staggered arrangement of the yarn bundles in the dyeing cage according to upper, middle and lower layers, and tight arrangement between adjacent yarn bundles.

5. The process for tension free anti fibrillation dyeing of lyocell blended yarn as claimed in claim 1 wherein: The tensionless one-bath dyeing / crosslinking is to pretreat the loaded tensionless loose yarn bundle, and the working solution formula for the pretreatment is: 2-4 g / L of refining agent, 0-2 g / L of caustic soda, 0-1 g / L of chelating agent, 0-6 g / L of hydrogen peroxide, and 0.5-1.5 g / L of oil removal agent, the treatment temperature is 100-110℃, and the holding time is 20-50 min.

6. The process for tension free anti fibrillation dyeing of lyocell blended yarn as claimed in claim 5 wherein: The refining agent is a non-ionic or anionic fatty alcohol polyoxyethylene ether compound, and the oil removal agent is a non-ionic or anionic surfactant.

7. The process for tension free anti fibrillation dyeing of lyocell blended yarn as claimed in claim 5 wherein: The specific steps of the two-step one-bath method for realizing dyeing and crosslinking are as follows: first, 10-30 g / L of sodium sulfate is added at a temperature of 40-50℃, 10-30 min later, active dyes are added in a linear feeding mode, then the temperature is raised to 55-60℃ at a heating rate of 1-1.5℃ / min, 10-30 min later, 5-10 g / L of soda ash is added in a linear feeding mode, 10-30 min later at 55-60℃, 2-6 g / L of Lyocell crosslinking agent is added in a linear feeding mode, and finally, dyeing and crosslinking are completed after 20-40 min of crosslinking and color fixing; the circulating pump power is maintained at 80%-90% of the rated power, and there is no need to reverse the direction during the whole process.

8. The process for tension free anti fibrillation dyeing of lyocell blended yarn as claimed in claim 7 wherein: The active dyes are one or both of monochlorotriazine and ethylenesulfone groups, and the amount of the active dyes is 0.5-6% of the weight of the yarn.

9. The process for tension free anti fibrillation dyeing of lyocell blended yarn as claimed in claim 1 wherein: The soaping process conditions are 1-3 g / L of soaping agent, a temperature of 80-95℃, and a time of 10-20 min; the hot water washing process conditions are a temperature of 80-98℃, a time of 10-15 min, and 2-3 times of washing.

10. The process for tension free anti fibrillation dyeing of lyocell blended yarn as claimed in claim 9 wherein: In the one-bath solidification / softening treatment, the solidification agent is a cationic solidification agent, and the amount is 1-3 g / L; the softening agent is an organic silicon softening agent or a cationic softening agent, and the amount is 2-5 g / L.

Images