A process for spinning lyocell / cotton blended compact siro spun yarn

Abstract

The application discloses a process method of lyocell / cotton blended compact cellophane yarn, and relates to the technical field of textile spinning, and comprises the following steps: step 1, opening and cleaning cotton: uniformly mixed fibers are obtained by gently opening and loosening modified lyocell fibers and modified cotton fibers; step 2, carding: uniformly webbed fibers are obtained; step 3, drawing: drawn fibers are obtained; step 4, roving: roving fibers are obtained; step 5, compact cellophane spinning: double-rove parallel symmetric feeding roving fibers are adopted, the negative pressure bundle pressure is controlled to be-2700Pa to-3100Pa, the yarn twist factor is 310-340, the spindle speed is 11000-13000r / min, and pre-yarn is obtained; and step 6, winding: the finished lyocell / cotton blended compact cellophane yarn is obtained. The application has the effect of significantly improving the blending quality, thereby realizing the purposes of improving use comfort and reducing color difference.

Description

Technical Field

[0001] This application relates to the field of textile spinning technology, and in particular to a process method for producing a lyocell / cotton blended compact Siro-spun yarn. Background Technology

[0002] With the upgrading of consumption in the high-end textile market, home textiles, intimate apparel, and luxury fabrics have placed stringent standardized requirements on the smoothness, pilling resistance, dimensional stability, and durability of yarns. Pure cotton fiber, with its excellent skin-friendliness, moisture absorption and breathability, and dyeability, is the mainstream base material for intimate textiles. However, it suffers from drawbacks such as easy wrinkling, deformation after washing, high fuzziness, and poor abrasion resistance and durability. Lyocell regenerated cellulose fiber, on the other hand, possesses outstanding advantages such as high smoothness, high drape, wrinkle resistance, and excellent luster, effectively compensating for the performance shortcomings of pure cotton fabrics. The industry commonly uses blending lyocell and cotton fibers to achieve complementary properties, resulting in fabrics that combine skin-friendly comfort with a crisp and aesthetically pleasing appearance. Therefore, lyocell / cotton blended yarns have become a core raw material for high-end textile fabrics and have broad market application prospects.

[0003] Currently, the preparation system of conventional lyocell / cotton blended yarns on the market mainly uses ordinary cotton fibers as the base material and conventional unmodified lyocell fibers as auxiliary materials. The fiber raw materials are simply physically blended without any targeted modification or adaptation treatment. The corresponding spinning processes mostly adopt traditional ring spinning, conventional Siro spinning, and conventional compact spinning as single spinning processes. The production process includes: manual proportioning of raw materials, conventional opening and cleaning of cotton blending, standard carding, multiple conventional drawing, conventional roving drafting, single-mode yarn twisting, and conventional winding.

[0004] However, due to the smooth surface, low crimp, and weak cohesion of existing lyocell fibers, and the high crimp and high coefficient of friction of cotton fibers, there is a problem of insufficient micro-mixing uniformity after the two fibers are blended. During the spinning process, phenomena such as fiber stratification, aggregation, and slippage occur, which seriously affect the blending quality of lyocell and cotton and needs to be improved. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a process for manufacturing a lyocell / cotton blended compact Sirospun yarn, which significantly improves the blend quality, thereby enhancing user comfort and reducing color difference. The specific solution is as follows: A process for producing a lyocell / cotton blended compact Siro-spun yarn includes the following steps: Step 1, Opening and cleaning cotton: Control the beater speed to 800-900r / min and the dust bar spacing to 7-9mm, gently open and loosen the modified lyocell fiber and modified cotton fiber to obtain a uniformly mixed fiber; Step 2, Carding: The uniformly mixed fibers are carded by controlling the cylinder speed at 340-380 r / min, the doffer speed at 16-20 r / min, and the flats running speed at 70-90 mm / min to obtain uniformly webped fibers; Step 3, drawing: The uniformly web-forming fibers are drawn through three drawing processes, controlling the total draw ratio to be 6.5-7.5 times, and the roller spacing to be 9mm×16mm-11mm×20mm, to obtain drawn fiber; Step 4, Roving: The drawn fibers are roving, and the roving twist coefficient is controlled to be 82-92, the draft ratio is 10.0-11.0 times, and the spindle speed is 750-850 r / min to obtain roving fibers; Step 5, Compact Siro yarn: The roving fibers are fed in parallel and symmetrically using double rovings, and the negative pressure bundling pressure is controlled at -2700Pa to -3100Pa, the yarn twist coefficient is 310-340, and the spindle speed is 11000-13000r / min to obtain pre-formed yarn; Step 6, Winding: The pre-formed yarn is processed by controlling the rotation speed of the winding drum at 800-1000 r / min and the winding tension coefficient at 0.07-0.09 to obtain the finished Lyocell / cotton blended compact Sirospun yarn.

[0006] Preferably, in step 1, the modified lyocell fiber and modified cotton fiber are laid flat and left to stand for 20-28 hours at a controlled temperature of 23-27℃ and a relative humidity of 60-70%.

[0007] Preferably, in step 1, the mass ratio of the modified lyocell fiber to the modified cotton fiber is (45-55):(45-55); the fiber length of the modified lyocell fiber and the modified cotton fiber is 36-40 mm, and the fiber fineness is 1.3-1.5D.

[0008] Preferably, the modified lyocell fiber is obtained by modifying lyocell fiber with polyol-carboxylic acid; the modified cotton fiber is obtained by modifying cotton fiber with glycerol-inorganic buffer salt.

[0009] Preferably, the polyol-carboxylic acid modification treatment includes mixing sorbitol and citric acid with deionized water at a mass ratio of (1.8-2.2):1 to obtain a polyol-carboxylic acid modification solution with a solute mass concentration of 2.0-3.0%; immersing lyocell fibers in the polyol-carboxylic acid modification solution, controlling the immersion bath ratio at 1:(15-25) and immersing at room temperature for 20-30 minutes, then removing and drying, controlling the drying temperature at 40-50℃ and the drying time at 10-20 minutes to obtain pre-dried fibers; then raising the temperature to 105-115℃ and curing for 2-5 minutes to obtain the finished modified lyocell fibers for later use.

[0010] Preferably, the method further includes taking SW10-25 / 1 type acidic silica sol with a particle size of 20-40nm, mixing it with deionized water to obtain a weakly acidic dispersion with a mass concentration of 0.4-0.8%, then immersing the modified lyocell fiber in the weakly acidic dispersion, controlling the bath ratio at 1:30, immersing at room temperature for 8-12 minutes, and then drying at a controlled temperature of 60-65℃ to obtain nano-silica filled lyocell fiber.

[0011] Preferably, the surface-active carboxyl group retention of the modified lyocell fiber is 0.2-0.4 mmol / g.

[0012] Preferably, the glycerol-inorganic buffer salt modification treatment includes mixing glycerol, inorganic buffer salt and deionized water to obtain a compound modification solution with a glycerol mass concentration of 1.0-1.5% and an inorganic buffer salt mass concentration of 0.2-0.4%; adjusting the temperature of the compound modification solution to 55-65℃ and controlling the pH value between 5.5-6.5, and impregnating cotton fibers with an impregnation bath ratio of 1:(15-20) for 15-25 minutes to obtain impregnated cotton fibers; and then drying the impregnated cotton fibers to obtain modified cotton fibers.

[0013] Preferably, the drying process includes pre-drying at a set temperature of 65-75℃ for 15-25 minutes, setting the temperature to 85-95℃ for 8-12 minutes, and then naturally rehydrating at room temperature for 20-28 hours to obtain the finished modified cotton fiber.

[0014] Preferably, the modified cotton fiber undergoes surface activation fine-tuning treatment, wherein the surface activation fine-tuning treatment involves spraying the modified cotton fiber with a sodium bicarbonate buffer solution with a pH of 7.0-7.5 at room temperature for 5-10 minutes to obtain modified cotton fiber with a surface active hydroxyl retention of 0.3-0.5 mmol / g.

[0015] As can be seen from the above solutions, this application provides a process for producing a lyocell / cotton blended compact Siro-spun yarn, which has the following beneficial effects: 1. By using the process of opening and cleaning cotton, carding, drawing, roving, and double roving to feed compact Siro yarn in parallel and symmetrically, and then winding the yarn, the modified lyocell fiber and modified cotton fiber will be evenly mixed. This will effectively avoid problems such as uneven stretching, fiber damage, and large amount of yarn hair residue, while significantly improving the uniformity of the drawn fiber, reducing the yarn breakage rate and subsequent weaving defects. This will effectively reduce the color difference and batch performance difference of the fabric, and significantly improve the forming density, structural stability and finished product qualification rate of the lyocell / cotton blended compact Siro yarn. 2. By using a polyol-carboxylic acid modified liquid composed of sorbitol and citric acid for impregnation and acidic silica sol for reinforcement, the surface microfibrils of the modified lyocell fiber will be effectively bound and the fiber fibrillation slippage phenomenon will be inhibited, thereby significantly improving the cohesion and wear resistance of the modified lyocell fiber. 3. By impregnating cotton fibers with a compound modified liquid composed of glycerol and inorganic buffer salt, the crimp uniformity of the modified cotton fibers is improved, and the surface rigid nodules and disordered crimp structure of the modified cotton fibers are reduced. 4. The surface-active carboxyl group retention of modified lyocell fibers obtained by polyol-carboxylic acid modification reaches 0.2-0.4 mmol / g, and the surface-active hydroxyl group retention of modified cotton fibers obtained by glycerol-inorganic buffer salt modification reaches 0.3-0.5 mmol / g. This allows the modified lyocell fibers and modified cotton fibers to undergo in-situ micro-esterification reaction and dynamic hydrogen bonding during the spinning process, thereby forming a multi-level composite cross-linked structure. This significantly improves the synchronization of fiber deformation during the spinning process, effectively reduces hairiness, and improves structural density. While improving the skin-friendly breathability, drape, and wrinkle resistance of the fabric, it avoids problems such as pilling, dimensional deformation after washing, and insufficient durability. Detailed Implementation

[0016] The technical solutions described below in conjunction with the embodiments of this application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0017] It should be mentioned that the modified lyocell fiber and modified cotton fiber have a fiber length of 36-40 mm and a fiber fineness of 1.3-1.5D. In the embodiments of this application, the fiber length is 38 mm and the fiber fineness is 1.33D.

[0018] The following will describe in detail the process method for producing a lyocell / cotton blended compact Sirospun yarn according to this application.

[0019] A process for producing a lyocell / cotton blended compact Siro-spun yarn includes the following steps: Step 1, Opening and cleaning cotton: Control the beater speed to 800-900 r / min, the dust bar spacing to 7-9 mm, and gently open the modified lyocell fiber and modified cotton fiber with a mass ratio of (45-55):(45-55). The modified lyocell fiber and modified cotton fiber are then laid flat and left to stand for 20-28 hours at a controlled temperature of 23-27℃ and a relative humidity of 60-70% to obtain a uniformly mixed fiber. Step 2, Carding: The uniformly mixed fibers are carded by controlling the cylinder speed at 340-380 r / min, the doffer speed at 16-20 r / min, and the flats running speed at 70-90 mm / min to obtain uniformly webped fibers; Step 3, drawing: The uniformly web-forming fibers are drawn through three drawing processes, controlling the total draw ratio to be 6.5-7.5 times, and the roller spacing to be 9mm×16mm-11mm×20mm, to obtain drawn fiber; Step 4, Roving: The drawn fibers are roving, and the roving twist coefficient is controlled to be 82-92, the draft ratio is 10.0-11.0 times, and the spindle speed is 750-850 r / min to obtain roving fibers; Step 5, Compact Siro yarn: The roving fibers are fed in parallel and symmetrically using double rovings, and the negative pressure bundling pressure is controlled at -2700Pa to -3100Pa, the yarn twist coefficient is 310-340, and the spindle speed is 11000-13000r / min to obtain pre-formed yarn; Step 6, Winding: The pre-formed yarn is processed by controlling the rotation speed of the winding drum at 800-1000 r / min and the winding tension coefficient at 0.07-0.09 to obtain the finished Lyocell / cotton blended compact Sirospun yarn.

[0020] It should be mentioned that the modified lyocell fiber in this application embodiment is obtained by polyol-carboxylic acid modification treatment of lyocell fiber. The polyol-carboxylic acid modification treatment includes mixing sorbitol and citric acid with deionized water at a mass ratio of (1.8-2.2):1 to obtain a polyol-carboxylic acid modification solution with a solute mass concentration of 2.0-3.0%; immersing lyocell fiber in the polyol-carboxylic acid modification solution, controlling the immersion bath ratio at 1:(15-25) and immersing at room temperature for 20-30 minutes, then removing and drying, controlling the drying temperature at 40-50℃ and the drying time at 10-20 minutes to obtain pre-dried fiber; then raising the temperature to 105-115℃ and curing for 2-5 minutes to obtain the finished modified lyocell fiber for use. To further enhance the cohesion and wear resistance of modified lyocell fibers, the method involves taking SW10-25 / 1 type acidic silica sol with a particle size of 20-40nm, mixing it with deionized water to obtain a weakly acidic dispersion with a mass concentration of 0.4-0.8%, immersing the modified lyocell fibers in the weakly acidic dispersion, controlling the bath ratio at 1:30, immersing at room temperature for 8-12 minutes, and then drying at a controlled temperature of 60-65℃ to obtain nano-silica filled lyocell fibers.

[0021] The surface-active carboxyl group retention of the modified lyocell fiber is 0.2-0.4 mmol / g.

[0022] Modified cotton fiber is obtained by modifying cotton fiber with glycerol-inorganic buffer salt. The glycerol-inorganic buffer salt modification process includes mixing glycerol, inorganic buffer salt and deionized water to obtain a compound modification solution with a glycerol mass concentration of 1.0-1.5% and an inorganic buffer salt mass concentration of 0.2-0.4%; adjusting the temperature of the compound modification solution to 55-65℃ and controlling the pH value between 5.5-6.5, impregnating the cotton fiber with an impregnation bath ratio of 1:(15-20) for 15-25 minutes to obtain impregnated cotton fiber; then drying the impregnated cotton fiber by pre-drying at a set temperature of 65-75℃ for 15-25 minutes and setting the temperature at 85-95℃ for 8-12 minutes, and finally allowing it to naturally rehydrate at room temperature for 20-28 hours to obtain the finished modified cotton fiber.

[0023] In order to effectively adjust the amount of surface-active hydroxyl groups retained in modified cotton fibers, the modified cotton fibers were subjected to surface activation fine-tuning treatment. The surface activation fine-tuning treatment was carried out by spraying the modified cotton fibers with sodium bicarbonate buffer solution with a pH of 7.0-7.5 at room temperature for 5-10 minutes to obtain modified cotton fibers with a surface-active hydroxyl group retention of 0.3-0.5 mmol / g.

[0024] Example 1 A process for producing a lyocell / cotton blended compact Siro-spun yarn includes the following steps: Step 1, Opening and Cleaning: Control the beater speed to 800 r / min and the dust bar spacing to 7 mm, gently loosen the modified lyocell fiber and modified cotton fiber with a mass ratio of 45:55, and then lay the modified lyocell fiber and modified cotton fiber flat and let them stand for 20 hours at a controlled temperature of 23℃ and a relative humidity of 60% to obtain a uniformly mixed fiber; the modified lyocell fiber and modified cotton fiber have a fiber length of 36 mm and a fiber fineness of 1.3D.

[0025] Step 2, Carding: The uniformly mixed fibers are carded at a controlled cylinder speed of 340 r / min, a doffer speed of 16 r / min, and a flatbed running speed of 70 mm / min to obtain uniformly webped fibers.

[0026] Step 3, drawing: The uniformly web-forming fibers are drawn through three drawing processes, controlling the total draw ratio to be 6.5 times and the roller spacing to be 9mm×16mm, to obtain drawn fibers.

[0027] Step 4, Roving: The drawn fibers are roving, with the roving twist coefficient controlled at 82, the draft ratio at 10.0, and the spindle speed at 750 r / min, to obtain roving fibers.

[0028] Step 5, Compact Siro yarn: The roving fibers are fed in parallel and symmetrically using double rovings, and the negative pressure bundling pressure is controlled at -2700Pa, the yarn twist coefficient is 310, and the spindle speed is 11000r / min to obtain pre-formed yarn.

[0029] Step 6, Winding: The pre-formed yarn is processed by controlling the rotation speed of the winding drum at 800 r / min and the winding tension coefficient at 0.07 to obtain the finished Lyocell / cotton blended compact Sirospun yarn.

[0030] It should be mentioned that the modified lyocell fiber in this application embodiment is obtained by polyol-carboxylic acid modification treatment of lyocell fiber. The polyol-carboxylic acid modification treatment includes mixing sorbitol and citric acid with deionized water at a mass ratio of 1.8:1 to obtain a polyol-carboxylic acid modification solution with a solute mass concentration of 2.0%; immersing lyocell fiber in the polyol-carboxylic acid modification solution, controlling the immersion bath ratio at 1:15, immersing at room temperature for 20 minutes, then removing and drying, controlling the drying temperature at 40°C and the drying time at 10 minutes to obtain pre-dried fiber; then raising the temperature to 105°C and curing for 2 minutes to obtain the finished modified lyocell fiber for use. To further enhance the cohesion and abrasion resistance of the modified lyocell fiber, the method involves mixing SW10-25 / 1 type acidic silica sol with a particle size of 20 nm with deionized water to obtain a weakly acidic dispersion with a mass concentration of 0.4%. The modified lyocell fiber is then immersed in the weakly acidic dispersion at a controlled bath ratio of 1:30 for 8 minutes at room temperature, followed by drying at 60°C to obtain nano-silica-filled lyocell fiber. The surface-active carboxyl group retention of the modified lyocell fiber is 0.2 mmol / g.

[0031] Modified cotton fiber is obtained by modifying cotton fiber with glycerol-inorganic buffer salt. The glycerol-inorganic buffer salt modification process includes mixing glycerol, inorganic buffer salt, and deionized water to obtain a compound modification solution with a glycerol mass concentration of 1.0% and an inorganic buffer salt mass concentration of 0.2%; adjusting the temperature of the compound modification solution to 55℃ and controlling the pH value between 5.5, impregnating the cotton fiber with an impregnation bath ratio of 1:15 for 15 minutes to obtain impregnated cotton fiber; then subjecting the impregnated cotton fiber to a drying process including pre-drying at a set temperature of 65℃ for 15 minutes and setting at a temperature of 85℃ for 8 minutes, followed by natural rehydration at room temperature for 20 hours to obtain the finished modified cotton fiber. In order to effectively adjust the amount of surface-active hydroxyl groups retained in modified cotton fibers, the modified cotton fibers were subjected to surface activation fine-tuning treatment. The surface activation fine-tuning treatment was carried out by spraying the modified cotton fibers with sodium bicarbonate buffer solution with a pH of 7.0 at room temperature for 5 minutes to obtain modified cotton fibers with a surface-active hydroxyl group retention of 0.3 mmol / g.

[0032] Example 2 A process for producing a lyocell / cotton blended compact Siro-spun yarn includes the following steps: Step 1, Opening and Cleaning: Control the beater speed to 850 r / min and the dust bar spacing to 8 mm, gently loosen the modified lyocell fiber and modified cotton fiber with a mass ratio of 50:50, and then lay the modified lyocell fiber and modified cotton fiber flat and let them stand for 24 hours at a controlled temperature of 25℃ and a relative humidity of 65% to obtain a uniformly mixed fiber; the modified lyocell fiber and modified cotton fiber have a fiber length of 38 mm and a fiber fineness of 1.33D.

[0033] Step 2, Carding: The uniformly mixed fibers are carded at a controlled cylinder speed of 360 r / min, a doffer speed of 18 r / min, and a flatbed running speed of 80 mm / min to obtain uniformly webped fibers.

[0034] Step 3, drawing: The uniformly web-forming fibers are drawn through three drawing processes, with the total draw ratio controlled at 7.0 times and the roller spacing specification at 10mm×18mm, to obtain drawn fibers.

[0035] Step 4, Roving: The drawn fibers are roving processed, with the roving twist coefficient controlled at 87, the draft ratio at 10.5, and the spindle speed at 800 r / min to obtain roving fibers.

[0036] Step 5, Compact Siro yarn: The roving fibers are fed in parallel and symmetrically using double rovings, and the negative pressure bundling pressure is controlled at -2900Pa, the yarn twist coefficient is 325, and the spindle speed is 12000r / min to obtain pre-formed yarn.

[0037] Step 6, Winding: The pre-formed yarn is processed by controlling the rotation speed of the winding drum at 900 r / min and the winding tension coefficient at 0.08 to obtain the finished Lyocell / cotton blended compact Sirospun yarn.

[0038] It should be mentioned that the modified lyocell fiber in this application embodiment is obtained by modifying lyocell fiber with polyol-carboxylic acid. The polyol-carboxylic acid modification treatment includes mixing sorbitol and citric acid with deionized water at a mass ratio of 2.0:1 to obtain a polyol-carboxylic acid modification solution with a solute mass concentration of 2.5%; immersing lyocell fiber in the polyol-carboxylic acid modification solution, controlling the immersion bath ratio at 1:20, immersing at room temperature for 25 minutes, then removing and drying, controlling the drying temperature at 45°C and the drying time at 15 minutes to obtain pre-dried fiber; then raising the temperature to 110°C and curing for 3 minutes to obtain the finished modified lyocell fiber for use. To further enhance the cohesion and abrasion resistance of the modified lyocell fibers, the process involves preparing a 0.6% (w / w) weakly acidic dispersion by mixing SW10-25 / 1 type acidic silica sol with deionized water at a particle size of 30 nm. The modified lyocell fibers are then immersed in this weakly acidic dispersion at a controlled bath ratio of 1:30 for 10 minutes at room temperature, followed by drying at 62°C to obtain nano-silica-filled lyocell fibers. The surface-active carboxyl group retention of the modified lyocell fibers is 0.3 mmol / g.

[0039] Modified cotton fiber is obtained by modifying cotton fiber with glycerol-inorganic buffer salt. The glycerol-inorganic buffer salt modification process includes mixing glycerol, inorganic buffer salt, and deionized water to obtain a compound modification solution with a glycerol mass concentration of 1.2% and an inorganic buffer salt mass concentration of 0.3%; adjusting the temperature of the compound modification solution to 60℃ and controlling the pH value between 6.0, impregnating the cotton fiber with an impregnation bath ratio of 1:18 for 20 minutes to obtain impregnated cotton fiber; then subjecting the impregnated cotton fiber to a drying process including pre-drying at a set temperature of 70℃ for 20 minutes and setting at a temperature of 90℃ for 10 minutes, followed by natural rehydration at room temperature for 24 hours to obtain the finished modified cotton fiber. In order to effectively adjust the amount of surface-active hydroxyl groups retained in modified cotton fibers, the modified cotton fibers were subjected to surface activation fine-tuning treatment. The surface activation fine-tuning treatment was carried out by spraying the modified cotton fibers with sodium bicarbonate buffer solution with a pH of 7.2 at room temperature for 8 minutes to obtain modified cotton fibers with a surface-active hydroxyl group retention of 0.4 mmol / g.

[0040] Example 3 A process for producing a lyocell / cotton blended compact Siro-spun yarn includes the following steps: Step 1, Opening and Cleaning: Control the beater speed to 900 r / min and the dust bar spacing to 9 mm, gently loosen the modified lyocell fiber and modified cotton fiber with a mass ratio of 55:45, and then allow the modified lyocell fiber and modified cotton fiber to lie flat and stand for 28 hours at a controlled temperature of 27℃ and a relative humidity of 70% to obtain a uniformly mixed fiber; the modified lyocell fiber and modified cotton fiber have a fiber length of 40 mm and a fiber fineness of 1.5D.

[0041] Step 2, Carding: The uniformly mixed fibers are carded at a controlled cylinder speed of 380 r / min, a doffer speed of 20 r / min, and a flatbed running speed of 90 mm / min to obtain uniformly webped fibers.

[0042] Step 3, drawing: The uniformly web-forming fibers are drawn through three drawing processes, controlling the total draw ratio to be 7.5 times and the roller spacing to be 11mm×20mm, to obtain drawn fibers.

[0043] Step 4, Roving: The drawn fibers are roving, with the roving twist coefficient controlled at 92, the draft ratio at 11.0, and the spindle speed at 850 r / min, to obtain roving fibers.

[0044] Step 5, Compact Siro yarn: The roving fibers are fed in parallel and symmetrically using double rovings, and the negative pressure bundling pressure is controlled at -3100Pa, the yarn twist coefficient is 340, and the spindle speed is 13000r / min to obtain pre-formed yarn.

[0045] Step 6, Winding: The pre-formed yarn is processed by controlling the rotation speed of the winding drum at 1000 r / min and the winding tension coefficient at 0.09 to obtain the finished Lyocell / cotton blended compact Sirospun yarn.

[0046] It should be mentioned that the modified lyocell fiber in this application embodiment is obtained by polyol-carboxylic acid modification of lyocell fiber. The polyol-carboxylic acid modification treatment includes mixing sorbitol and citric acid with deionized water at a mass ratio of 2.2:1 to obtain a polyol-carboxylic acid modification solution with a solute mass concentration of 3.0%; immersing lyocell fiber in the polyol-carboxylic acid modification solution, controlling the immersion bath ratio at 1:25, immersing at room temperature for 30 minutes, then removing and drying, controlling the drying temperature at 50°C and the drying time at 20 minutes to obtain pre-dried fiber; then raising the temperature to 115°C and curing for 5 minutes to obtain the finished modified lyocell fiber for use. To further enhance the cohesion and abrasion resistance of the modified lyocell fiber, the method involves preparing a weakly acidic dispersion with a mass concentration of 0.8% by mixing SW10-25 / 1 type acidic silica sol with a particle size of 40 nm and deionized water. The modified lyocell fiber is then immersed in the weakly acidic dispersion at a controlled bath ratio of 1:30 for 12 minutes at room temperature, followed by drying at 65°C to obtain nano-silica-filled lyocell fiber. The surface-active carboxyl group retention of the modified lyocell fiber is 0.4 mmol / g.

[0047] Modified cotton fiber is obtained by modifying cotton fiber with glycerol-inorganic buffer salt. The glycerol-inorganic buffer salt modification process includes mixing glycerol, inorganic buffer salt, and deionized water to obtain a compound modification solution with a glycerol mass concentration of 1.5% and an inorganic buffer salt mass concentration of 0.4%; adjusting the temperature of the compound modification solution to 65℃ and controlling the pH value between 6.5, impregnating the cotton fiber with an impregnation bath ratio of 1:20 for 25 minutes to obtain impregnated cotton fiber; then subjecting the impregnated cotton fiber to a drying process including pre-drying at a set temperature of 75℃ for 25 minutes and setting at a temperature of 95℃ for 12 minutes, followed by natural rehydration at room temperature for 28 hours to obtain the finished modified cotton fiber. In order to effectively adjust the amount of surface-active hydroxyl residue in modified cotton fibers, the modified cotton fibers were subjected to surface activation fine-tuning treatment. The surface activation fine-tuning treatment was carried out by spraying the modified cotton fibers with sodium bicarbonate buffer solution with a pH of 7.5 at room temperature for 10 min, resulting in modified cotton fibers with a surface-active hydroxyl residue of 0.5 mmol / g.

[0048] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the modified lyocell fiber in Comparative Example 1 was not modified by acidic silica sol.

[0049] Comparative Example 2 The difference between Comparative Example 2 and Comparative Example 1 is that in Comparative Example 2, Lyocell fiber is used instead of modified Lyocell fiber.

[0050] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the modified cotton fibers in Comparative Example 3 were not subjected to surface activation fine-tuning treatment.

[0051] Comparative Example 4 The difference between Comparative Example 4 and Comparative Example 3 is that Comparative Example 4 uses cotton fiber instead of modified cotton fiber.

[0052] Comparative Example 5 The difference between Comparative Example 5 and Comparative Example 4 is that in Comparative Example 5, Lyocell fiber was used instead of modified Lyocell fiber.

[0053] Performance testing: 1. Test environment: The temperature was 25℃ and the relative humidity was 65% for 24 hours to achieve humidity equilibration. 2. Referring to GB / T 3916-2013 "Determination of breaking strength and elongation at break of single yarn in packaged textiles", an electronic single yarn tensile tester was used to test the yarn, with the test interval controlled at 500 mm and the tensile speed at 500 mm / min, and the single yarn breaking strength (cN / tex) was obtained. 3. Referring to GB / T 3292.1-2022 "Textiles - Test Methods for Yarn Evenness - Part 1: Capacitance Method", a capacitive yarn evenness tester was used for testing. The test speed was controlled at 400 m / min, and the test length for each group was 1000 m. The yarn evenness CV value (%) was obtained. 4. Refer to FZ / T 90096-2017 "Test Method for Yarn Hairiness" and use a laser hairiness tester to test the number of harmful hairs of 3mm and above; 5. Referring to GB / T 4802.1-2020 "Pilling Test of Textiles - Circular Trajectory Method", a circular trajectory pilling tester was used to test the pilling resistance level. The pilling resistance level was evaluated after 500 pilling cycles. The rating was divided into 1-9 levels, with level 9 being the best and level 1 being the worst. 6. Referring to GB / T 8629-2017 "Home Washing and Drying Procedures for Textile Testing", the yarn shrinkage rate was tested after 5 washes using the 4A washing procedure.

[0054] The performance test results are shown in Table 1 below.

[0055] Table 1 Performance Test Results

[0056] As shown in Table 1 above, in Examples 1 to 3, with the increase in the amount of surface-active carboxyl groups retained in the modified lyocell fiber, the nano-silica in the acidic silica sol forms a dense anchoring and reinforcing layer on the surface of the modified lyocell fiber. The modified cotton fiber is buffered and shaped by glycerol and sodium dihydrogen phosphate as an inorganic buffer salt, and its strength is enhanced by activation with sodium bicarbonate. This makes the interfacial esterification crosslinking and hydrogen bonding between the modified lyocell fiber and the modified cotton fiber in the blending process significantly improve the fiber cohesion and deformation synchronization, thereby achieving the effects of gradually increasing strength, continuously reducing yarn unevenness, significantly reducing hairiness, and continuously improving anti-pilling and dimensional stability.

[0057] Comparative Example 1: Due to the lack of a dense anchoring and reinforcing layer formed by nano-silica in acidic silica sol on the surface of the modified lyocell fiber, microfiber slippage and lifting easily occur during spinning and drafting, resulting in a significant increase in the number of harmful hairs and poor yarn evenness. Simultaneously, the lack of interfacial support and abrasion-resistant protection leads to uneven surface friction coefficients, decreased yarn abrasion resistance, and a lower pilling grade. Comparative Example 2: Due to the strong inertness of the lyocell fiber surface and the lack of active cross-linking sites, it physically adheres to the modified cotton fiber during blending and spinning, lacking interfacial chemical bonding. This results in significant slippage differences and low cohesion between the lyocell and modified cotton fibers. Comparative Example 3: Due to the lack of surface activation with sodium bicarbonate buffer, the surface hydroxyl groups of the modified cotton fiber are in a closed and passivated state, with a low number of effective active hydroxyl groups. Therefore, it is difficult to form an effective esterification cross-linking interface between the modified lyocell and modified cotton fibers, leading to a slight decrease in strength, evenness, and anti-pilling properties, and an increase in washing shrinkage. Comparative Example 4 shows that due to the disordered crimping of cotton fibers, the presence of many rigid nodules on the surface, and poor fiber consistency, the cotton fibers, when blended with modified Lyocell fibers, suffer from poor physical property compatibility, leading to problems such as aggregation and uneven density in certain areas.

[0058] Comparative Example 5 shows that due to the asynchronous deformation and loose interfacial bonding between lyocell fiber and cotton fiber during the spinning process, the resulting yarn has problems such as excessive hairiness, poor evenness, low strength, easy pilling, and large deformation after washing.

[0059] In summary, this application provides a process for producing a lyocell / cotton blended compact Siro-spun yarn. This process involves opening and cleaning the cotton, carding, drawing, roving, parallel and symmetrical feeding of the compact Siro yarn with double rovings, and then winding the yarn. This ensures a uniform mixing of modified lyocell and modified cotton fibers. While effectively avoiding problems such as uneven drafting, fiber damage, and excessive yarn hairiness, it significantly improves the uniformity of the drawn fibers, reduces yarn breakage rate and subsequent weaving defects, effectively reduces fabric color difference and batch performance variations, and significantly improves the forming density, structural stability, and finished product qualification rate of the lyocell / cotton blended compact Siro-spun yarn. Specifically, for the modified lyocell fibers and modified cotton fibers used, impregnation treatment with a polyol-carboxylic acid modified liquid composed of sorbitol and citric acid, followed by acidic silica sol filling and reinforcement, effectively binds the surface microfibrils of the modified lyocell fibers and inhibits fiber fibrillation slippage, thereby significantly improving the cohesion and abrasion resistance of the modified lyocell fibers. Simultaneously, impregnation treatment of cotton fibers with a compound modified liquid composed of glycerol and inorganic buffer salts improves the crimp uniformity of the modified cotton fibers and reduces the surface rigid nodules and disordered crimp structure. In the process of combining modified lyocell fibers and modified cotton fibers, the surface-active carboxyl group retention of modified lyocell fibers obtained by polyol-carboxylic acid modification treatment reaches 0.2-0.4 mmol / g, and the surface-active hydroxyl group retention of modified cotton fibers obtained by glycerol-inorganic buffer salt modification treatment reaches 0.3-0.5 mmol / g. This allows the modified lyocell fibers and modified cotton fibers to undergo in-situ micro-esterification reaction and dynamic hydrogen bonding during the spinning process, thereby forming a multi-level composite cross-linked structure that significantly improves the synchronization of fiber deformation during the spinning process, effectively reduces hairiness, and improves structural density. While improving the skin-friendly breathability and drape and wrinkle resistance of the fabric, it avoids problems such as pilling, dimensional deformation after washing, and insufficient durability.

[0060] The terms “first,” “second,” “third,” “fourth,” etc., used in this application (if applicable) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, or apparatus that includes a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, or apparatus.

[0061] It should be noted that the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0062] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A process for producing a compact Sirospun yarn made from a lyocell / cotton blend, characterized in that, The steps include the following: Step 1, Opening and cleaning cotton: Control the beater speed to 800-900r / min and the dust bar spacing to 7-9mm, gently open and loosen the modified lyocell fiber and modified cotton fiber to obtain a uniformly mixed fiber; Step 2, Carding: The uniformly mixed fibers are carded by controlling the cylinder speed at 340-380 r / min, the doffer speed at 16-20 r / min, and the flats running speed at 70-90 mm / min to obtain uniformly webped fibers; Step 3, drawing: The uniformly web-forming fibers are drawn through three drawing processes, controlling the total draw ratio to be 6.5-7.5 times, and the roller spacing to be 9mm×16mm-11mm×20mm, to obtain drawn fiber; Step 4, Roving: The drawn fibers are roving, and the roving twist coefficient is controlled to be 82-92, the draft ratio is 10.0-11.0 times, and the spindle speed is 750-850 r / min to obtain roving fibers; Step 5, Compact Siro yarn: The roving fibers are fed in parallel and symmetrically using double rovings, and the negative pressure bundling pressure is controlled at -2700Pa to -3100Pa, the yarn twist coefficient is 310-340, and the spindle speed is 11000-13000r / min to obtain pre-formed yarn; Step 6, Winding: The pre-formed yarn is processed by controlling the rotation speed of the winding drum at 800-1000 r / min and the winding tension coefficient at 0.07-0.09 to obtain the finished Lyocell / cotton blended compact Sirospun yarn.

2. The process for producing a lyocell / cotton blended compact Sirospun yarn according to claim 1, characterized in that: In step 1, the modified lyocell fiber and modified cotton fiber are laid flat and left to stand for 20-28 hours at a controlled temperature of 23-27℃ and a relative humidity of 60-70%.

3. The process for producing a lyocell / cotton blended compact Sirospun yarn according to claim 1, characterized in that: In step 1, the mass ratio of the modified lyocell fiber to the modified cotton fiber is (45-55):(45-55); the fiber length of the modified lyocell fiber and the modified cotton fiber is 36-40 mm, and the fiber fineness is 1.3-1.5D.

4. The process for producing a lyocell / cotton blended compact Sirospun yarn according to claim 1, characterized in that: The modified lyocell fiber is obtained by modifying lyocell fiber with polyol-carboxylic acid; the modified cotton fiber is obtained by modifying cotton fiber with glycerol-inorganic buffer salt.

5. The process for producing a lyocell / cotton blended compact Sirospun yarn according to claim 4, characterized in that: The polyol-carboxylic acid modification process includes mixing sorbitol and citric acid with deionized water at a mass ratio of (1.8-2.2):1 to obtain a polyol-carboxylic acid modification solution with a solute mass concentration of 2.0-3.0%; immersing lyocell fibers in the polyol-carboxylic acid modification solution, controlling the immersion bath ratio at 1:(15-25) and immersing at room temperature for 20-30 minutes, then removing and drying them, controlling the drying temperature at 40-50℃ and the drying time at 10-20 minutes to obtain pre-dried fibers; then raising the temperature to 105-115℃ and curing for 2-5 minutes to obtain the finished modified lyocell fibers for later use.

6. The process for producing a lyocell / cotton blended compact Sirospun yarn according to claim 5, characterized in that: The method also includes taking SW10-25 / 1 type acidic silica sol with a particle size of 20-40nm, mixing it with deionized water to obtain a weakly acidic dispersion with a mass concentration of 0.4-0.8%, then immersing the modified lyocell fiber in the weakly acidic dispersion, controlling the bath ratio at 1:30, immersing at room temperature for 8-12 minutes, and then drying at a controlled temperature of 60-65℃ to obtain nano-silica filled lyocell fiber.

7. The process for producing a lyocell / cotton blended compact Sirospun yarn according to claim 5, characterized in that: The modified lyocell fiber has a surface-active carboxyl group retention of 0.2-0.4 mmol / g.

8. The process for producing a lyocell / cotton blended compact Sirospun yarn according to claim 4, characterized in that: The glycerol-inorganic buffer salt modification treatment includes mixing glycerol, inorganic buffer salt and deionized water to obtain a compound modified solution with a glycerol mass concentration of 1.0-1.5% and an inorganic buffer salt mass concentration of 0.2-0.4%. Adjust the temperature of the compounded modification solution to 55-65℃ and control the pH value between 5.5-6.

5. The impregnation bath ratio is 1:(15-20). Impregnate the cotton fibers for 15-25 minutes to obtain impregnated cotton fibers. Then, dry the impregnated cotton fibers to obtain modified cotton fibers.

9. The process for producing a lyocell / cotton blended compact Sirospun yarn according to claim 8, characterized in that: The drying process includes pre-drying at a set temperature of 65-75℃ for 15-25 minutes, setting the temperature to 85-95℃ for 8-12 minutes, and then naturally rehydrating at room temperature for 20-28 hours to obtain the finished modified cotton fiber.

10. The process for producing a lyocell / cotton blended compact Sirospun yarn according to claim 8, characterized in that: The modified cotton fiber undergoes a surface activation fine-tuning treatment, which involves spraying the modified cotton fiber with a sodium bicarbonate buffer solution with a pH of 7.0-7.5 at room temperature for 5-10 minutes to obtain modified cotton fiber with a surface active hydroxyl retention of 0.3-0.5 mmol / g.

Images