A bio-based moisture-wicking fabric and method of making the same

Abstract

The application belongs to the technical field of knitted fabric, and particularly relates to a bio-based moisture-conducting fabric and a preparation method thereof. The preparation method comprises the following steps: composite spinning of modified nylon filaments and spandex filaments to obtain nylon / spandex composite yarn; feeding the composite yarn as first yarn and the modified nylon filaments as second yarn into a weft-knitting circular knitting machine at the same time, and knitting the fabric by knitting; the fabric has a three-layer composite structure of an inner layer, an intermediate layer and an outer layer, the inner layer is knitted by the first yarn in a plating stitch, the outer layer is knitted by the first yarn in a weft plain stitch, and the intermediate layer is knitted by the second yarn in a tuck stitch. The modified nylon filaments are prepared by melt spinning of a copolymerized modified polyamide prepared by reaction of bio-based polyamide 56, caprolactam, dimethyl isophthalate-5-sodium sulfonate and double-end hydroxyl quaternary ammonium polyether. The fabric prepared by the application has excellent moisture-absorbing, moisture-conducting, antibacterial and antistatic properties.

Description

Technical Field

[0001] This invention belongs to the field of knitted fabric technology, specifically relating to a bio-based moisture-wicking fabric and its preparation method. Background Technology

[0002] As the textile industry transforms towards green and sustainable development, bio-based materials, due to their renewable and environmentally friendly characteristics, have become a research hotspot in the development of functional fabrics. Moisture-wicking fabrics, as an important component of sportswear and leisurewear, function primarily to quickly conduct sweat from the skin's surface to the outer layer of the fabric for evaporation, thus maintaining wearing comfort. Knitted structures, with their unique interlocking loop structure, possess excellent extensibility and breathability, making them ideal fabric structures for achieving moisture-wicking functionality. Therefore, combining the moisture-wicking properties of bio-based fiber materials with those of knitted structures to develop fabrics that are both environmentally friendly and comfortable has become an important direction for current technological development in the industry.

[0003] In existing technologies, the preparation of moisture-wicking knitted fabrics mainly follows two technical routes: one is the physical structure modification route, which utilizes the fiber capillary effect to design irregular fabric cross-sections (such as cross-shaped or Y-shaped) or construct differential capillary effects between the inner and outer layers of the fabric. Common methods include using a double-knitted structure to create a wetting gradient between the less hydrophilic inner layer and the more hydrophilic outer layer, or generating a pressure gradient through differences in fabric density, thereby driving unidirectional sweat conduction; the other is the chemical finishing modification route, which creates hydrophilic or hydrophobic differences between the front and back of the fabric by applying hydrophilic or water-repellent finishing treatments, giving it moisture-wicking properties. However, existing technologies generally have the following problems: First, in terms of material selection and functional modification, most high-performance moisture-wicking fibers are still mainly petroleum-based synthetic fibers (such as polyester, polyamide 66, etc.), which are highly dependent on non-renewable resources and are difficult to degrade after disposal. Although new materials such as bio-based polyamide 56 have emerged in recent years, their applications are mostly limited to conventional fiber preparation, lacking systematic molecular design and modification for moisture-wicking functions. In existing technologies, when synthetic fibers are endowed with hydrophilic, antibacterial, and antistatic functions through physical blending or finishing, the functional additives and the fiber matrix rely solely on physical interactions, resulting in weak bonding and easy migration and loss during washing or use, leading to poor functional durability. Meanwhile, how to achieve integrated chemical bonding modification of multiple functions such as hydrophilicity, antibacterial properties, and antistatic properties by introducing bio-based functional monomers while maintaining the excellent mechanical properties of synthetic fibers like nylon remains a pressing technological challenge. Secondly, in terms of fabric structure design, simple physical structural modification often fails to balance excellent moisture wicking rate and wearing comfort. The spinning and weaving processes of profiled fibers are complex and costly; while chemical finishing methods face problems such as poor durability of finishing agents and significant attenuation of moisture wicking effect after multiple washes, and some functional finishing agents themselves pose environmental and health risks. Existing moisture-wicking fabrics mostly adopt single-layer or simple double-layer structures, making it difficult to simultaneously achieve rapid sweat absorption in the inner layer, rapid conduction in the middle layer, and efficient evaporation in the outer layer. Furthermore, they are prone to sweat backflow leading to a damp and cold feeling, lacking a systematic and synergistic design from fiber function to fabric structure. Third, in terms of the application of bio-based fibers, although existing bio-based fibers (such as polylactic acid fiber, seaweed fiber, etc.) have environmental advantages, they usually have problems such as low strength, excessive or insufficient hydrophilicity, and poor heat resistance. When directly applied to the preparation of moisture-wicking fabrics, it is difficult to achieve stable and efficient one-way sweat transmission function through conventional processes, and it cannot simultaneously meet the multiple performance requirements of the fabric for soft hand feel, long-lasting moisture wicking, etc.

[0004] Therefore, developing a bio-based moisture-wicking fabric with durable moisture-wicking properties and environmental friendliness, by achieving chemical bonding and anchoring of functional additives at the molecular level, leveraging the intrinsic hydrophilicity of bio-based polyamides at the fiber level, constructing a gradient moisture-wicking structure at the fabric level, and organically combining the three to produce synergistic effects, has become an important technological direction to meet the growing demand of the green consumer market. Summary of the Invention

[0005] To address the aforementioned issues, the present invention aims to propose a bio-based moisture-wicking fabric and its preparation method, thereby solving problems in the prior art such as poor durability due to easy migration and loss of functional additives, lack of multifunctional synergistic modification of synthetic fibers, difficulty in achieving both rapid moisture wicking and wearing comfort in a single fabric structure, and insufficient strength and uncontrollable hydrophilicity of existing bio-based fibers.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method for preparing a bio-based moisture-wicking fabric, comprising the following steps: Step 1: The modified nylon filament and spandex filament are composite spun to obtain nylon / spandex composite yarn; wherein, the modified nylon filament is obtained by melt spinning of a copolymer modified polyamide prepared by reacting bio-based polyamide 56, caprolactam, sodium dimethyl isophthalate-5-sulfonate and double-hydroxyl-terminated quaternized polyether. Step 2: Using a weft-knitting circular knitting machine, the nylon / spandex composite yarn is used as the first yarn, and the modified nylon filament is used as the second yarn. The first and second yarns are fed in simultaneously through a yarn feeder, and a bio-based moisture-wicking fabric is obtained through a knitting process. The bio-based moisture-wicking fabric has a three-layer composite structure: an inner layer, a middle layer, and an outer layer. The inner layer is formed by knitting the first yarn with a padded weave, the outer layer is formed by knitting the first yarn with a plain weave, and the middle layer is formed by knitting the second yarn with a tuck weave. The tuck loops of the tuck weave are connected to the loops of the inner layer and the outer layer, respectively.

[0007] Preferably, the nylon / spandex composite yarn in step one is a covered yarn formed by covering the modified nylon filament with the spandex filament; the mass ratio of the modified nylon filament to the spandex filament is (82-90):(10-18); the covering process includes: the twist direction is S twist, the twist degree is 500-800 twists, and the spandex draw ratio is 2-3.5 times.

[0008] Preferably, the method for preparing the modified nylon filament in step one specifically includes the following steps: S1. Sodium dimethyl isophthalate-5-sulfonate, bi-hydroxyl-terminated quaternized polyether and catalyst 1 are mixed and reacted to obtain a prepolymer. Bio-based polyamide 56, caprolactam and catalyst 2 are added to the prepolymer and the reaction continues. After the reaction is completed, the temperature is lowered, a stabilizer is added, and the reaction is repeated. After the reaction is completed, the product is discharged to obtain the copolymerized modified polyamide. S2. The copolymerized polyamide is melt-spun, wound, drawn, and heat-set to obtain the modified nylon filament.

[0009] Preferably, in S1, the mass ratio of sodium dimethyl isophthalate-5-sulfonate, dihydroxylated quaternized polyether, bio-based polyamide 56, and caprolactam is (5-15):(10-25):(70-85):(15-30), the amount of catalyst 1 added is 0.1%-0.5% of the total mass of sodium dimethyl isophthalate-5-sulfonate and dihydroxylated quaternized polyether, and the amount of catalyst 2 added is 0.05%-0.1% of the total mass of bio-based polyamide 56 and caprolactam. The stabilizer is added at 0.1%-0.3% of the total mass of bio-based polyamide 56 and caprolactam. The reaction conditions are: under nitrogen protection, at a temperature of 180-220℃ for 2-4 hours; the reaction continues under nitrogen protection, at a pressure of 1.8-2.2MPa, at a temperature of 230-255℃ for 1.5-2.5 hours; and the reaction is repeated under a pressure of <100Pa, at a temperature of 240-270℃ for 3-5 hours.

[0010] Preferably, catalyst 1 comprises dibutyltin oxide, catalyst 2 comprises antimony trioxide, and stabilizer comprises triphenyl phosphate.

[0011] Preferably, the double-hydroxyl-terminated quaternized polyether is prepared by the following steps: Step (1): Mix polyethylene glycol and epichlorohydrin at a molar ratio of 1:(2-2.5), add 0.5-2% of tin tetrachloride / trichloroacetic acid mixed catalyst by mass of polyethylene glycol, and react at 30-60℃ for 6-12h to obtain double-hydroxyl-terminated polyether; Step (2): Heat the bihydroxyl-terminated polyether to a set temperature, and add a 30-50% (w / w) triethylamine aqueous solution. The amount of triethylamine added is 1-1.2 times the molar amount of epichlorohydrin. React at the set temperature for 4-8 hours. After the reaction is complete, purify to obtain the bihydroxyl-terminated quaternized polyether. The set temperature is 60-90℃.

[0012] Preferably, in step S2, the spinning temperature is 250-280℃, the winding speed is 3000-4500m / min, the drawing temperature is 60-90℃, the drawing ratio is 2.5-4 times, and the heat setting temperature is 100-130℃.

[0013] Preferably, in step two, the cylinder diameter of the weft knitting circular knitting machine is 30-38 inches, the needle size is 24-32G, and the rotation speed is 15-22 r / min; the feeding tension of the first yarn is 3-6 cN, and the feeding tension of the second yarn is 2-4 cN.

[0014] Preferably, in step two, the tufting structure of the middle layer adopts a three-way knitting structure, specifically: the first way tufts on odd-numbered needles and forms loops on even-numbered needles, the second way forms loops on odd-numbered needles and tufts on even-numbered needles, and the third way forms loops on all needles; the ratio of the tufting loop length to the loop length is (0.4-0.6):1.

[0015] The present invention also discloses a bio-based moisture-wicking fabric prepared by the preparation method of the bio-based moisture-wicking fabric as described above.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention modifies polyamide by introducing a double-hydroxyl-terminated quaternized polyether and sodium dimethyl isophthalate-5-sulfonate, constructing a chemically bonded hydrophilic-antibacterial-antistatic multifunctional structure. The double-hydroxyl-terminated quaternized polyether has polyethylene glycol as the main chain and reactive hydroxyl groups at both ends. During the copolymerization process, it undergoes a copolymerization reaction with caprolactam and sodium dimethyl isophthalate-5-sulfonate, covalently embedding the quaternary ammonium salt cationic group, the hydrophilic polyether segment of ethylene glycol, and the sulfonic acid group into the polymer network with bio-based polyamide 56 as the main chain. This solves the problem of easy migration and loss of functional additives in traditional physical blending at the molecular level; the polyether segment and the sulfonic acid group synergistically endow the modified polyamide with... The modified nylon filament exhibits durable hydrophilicity and rapid moisture wicking capability; quaternary ammonium salt groups provide long-lasting antibacterial properties, while the quaternary ammonium salt cations and sulfonic acid anions form ion pairs, dissipating static charge through ion conduction mechanisms, thus endowing the modified nylon filament with excellent antistatic properties. Furthermore, all functional groups are chemically anchored within the polyamide, ensuring stable performance. The introduction of flexible polyether segments significantly improves the toughness of the polyamide, while the bio-based polyamide 56 matrix itself, due to its odd-even carbon atom structure, possesses superior hydrophilicity and soft hand feel compared to conventional polyamides. This, combined with the introduced functional segments, creates a dual hydrophilic synergistic effect, enabling the modified nylon filament to possess both excellent softness and rapid moisture wicking properties. This invention achieves gradient moisture wicking and single-layer moisture wicking through the synergistic design of a three-layer composite knitted structure. The inner layer uses a yarn-filled weave to concentrate the nylon / spandex composite yarns on the skin-contacting surface, forming a rapid moisture-absorbing zone. The middle layer uses a tucked weave, where the loops create longitudinally continuous capillary channels, quickly guiding the sweat absorbed by the inner layer to the outer layer. The outer layer uses a weft-knit weave to concentrate the yarns on the outer surface, forming a large diffusion area to accelerate sweat evaporation. The three-layer structure is woven in one piece using tucked loops, eliminating the need for bonding or adhesives and ensuring the fabric's integrity. Simultaneously, by controlling the ratio of the tucked loop length to the loop length, a capillary pressure gradient is created along the fabric thickness, driving sweat unidirectionally from the inside out, avoiding the damp and cold feeling caused by sweat backflow. This invention integrates molecular-level hydrophilicity, antibacterial, and antistatic properties. The combination of electromodification and the gradient moisture-wicking structure at the fabric scale produces a significant synergistic effect. The hydrophilic properties of the modified fibers themselves, combined with the capillary effect of the fabric structure, result in excellent moisture wicking rate and liquid absorption. The ion-pairing structure of quaternary ammonium salts and sulfonic acid groups endows the fabric with durable antistatic properties, avoiding static electricity problems during wear. The elastic recovery of the spandex core layer in the covered yarn structure provides the fabric with good body-fitting comfort, while the micro-convex structure formed by the outer layer's tuck weave further increases the evaporation area. The use of bio-based polyamide 56 matrix maintains excellent mechanical properties while improving the fabric's bio-based carbon content and sustainability, enabling the fabric to meet comprehensive requirements such as rapid moisture wicking, durable softness, antibacterial properties, antistatic properties, and environmental friendliness. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] Example 1 This embodiment provides a method for preparing a quaternized polyether with hydroxyl-terminated ends, comprising the following steps: Step (1): Mix polyethylene glycol 400 and epichlorohydrin at a molar ratio of 1:2.2, add 1% of the mass of polyethylene glycol tin tetrachloride / trichloroacetic acid mixed catalyst, and react at 45°C for 9 hours to obtain a double-hydroxyl-terminated polyether. Step (2): Heat the hydroxyl-terminated polyether to 75°C, add a 40% (w / w) triethylamine aqueous solution, the amount of triethylamine added is 1.1 times the molar amount of epichlorohydrin, and react. The reaction conditions are 6 hours at 75°C. After the reaction is completed, remove excess triethylamine, epichlorohydrin and water by vacuum distillation to obtain crude product. Add acetone (20 times the volume of crude product) to the crude product, stir to precipitate the target product, centrifuge, collect the precipitate, wash the precipitate three times with fresh acetone, and dry it in a vacuum drying oven at 50°C to constant weight to obtain hydroxyl-terminated quaternized polyether.

[0019] Example 2 This embodiment provides a method for preparing modified nylon filament, including the following steps: S1. Sodium dimethyl isophthalate-5-sulfonate, the quaternized polyether with hydroxyl-terminated ends prepared in Example 1, and dibutyltin oxide were mixed and reacted at 180°C for 4 hours under nitrogen protection to obtain a prepolymer. Bio-based polyamide 56, caprolactam, and antimony trioxide were added to the prepolymer, and the mixture was reacted at 230°C for 2.5 hours under nitrogen protection and a pressure of 1.8 MPa. After the reaction was completed, the temperature was lowered to below 200°C, and triphenyl phosphate was added. The mixture was then reacted at 240°C for 5 hours under a pressure of <100 Pa. After the reaction was completed, the product was discharged to obtain a copolymerized modified polyamide. The mass ratio of sodium dimethyl isophthalate-5-sulfonate, hydroxyl-terminated quaternized polyether, bio-based polyamide 56, and caprolactam was 15:25:70:30. The amount of dibutyltin oxide added was 0.1% of the total mass of sodium dimethyl isophthalate-5-sulfonate and hydroxyl-terminated quaternized polyether. The amount of antimony trioxide added was 0.05% of the total mass of bio-based polyamide 56 and caprolactam. The amount of triphenyl phosphate added was 0.1% of the total mass of bio-based polyamide 56 and caprolactam. S2. The copolymerized polyamide is melt-spun, wound, drawn, and heat-set to obtain the modified nylon filament; wherein the spinning temperature is 250℃, the winding speed is 3000m / min, the drawing temperature is 60℃, the drawing ratio is 2.5 times, and the heat-setting temperature is 100℃; the single fiber fineness of the modified nylon filament is 4dtex.

[0020] Example 3 This embodiment provides a method for preparing modified nylon filament, including the following steps: S1. Sodium dimethyl isophthalate-5-sulfonate, the quaternized polyether with hydroxyl-terminated ends prepared in Example 1, and dibutyltin oxide were mixed and reacted at 220°C for 2 hours under nitrogen protection to obtain a prepolymer. Bio-based polyamide 56, caprolactam, and antimony trioxide were added to the prepolymer, and the mixture was reacted at 255°C for 1.5 hours under nitrogen protection and a pressure of 2.2 MPa. After the reaction was completed, the temperature was lowered to below 200°C, and triphenyl phosphate was added. The mixture was then reacted at 270°C for 3 hours under a pressure of <100 Pa. After the reaction is complete, the product is discharged to obtain a copolymerized modified polyamide. The mass ratio of sodium dimethyl isophthalate-5-sulfonate, hydroxyl-terminated quaternized polyether, bio-based polyamide 56, and caprolactam is 5:10:85:15. The amount of dibutyltin oxide added is 0.5% of the total mass of sodium dimethyl isophthalate-5-sulfonate and hydroxyl-terminated quaternized polyether. The amount of antimony trioxide added is 0.1% of the total mass of bio-based polyamide 56 and caprolactam. The amount of triphenyl phosphate added is 0.3% of the total mass of bio-based polyamide 56 and caprolactam. S2. The copolymerized modified polyamide is melt-spun, wound, drawn, and heat-set to obtain the modified nylon filament; wherein the spinning temperature is 280℃, the winding speed is 4500m / min, the drawing temperature is 90℃, the drawing ratio is 4 times, and the heat-setting temperature is 130℃; the single fiber fineness of the modified nylon filament is 1.8dtex.

[0021] Example 4 This embodiment provides a method for preparing modified nylon filament, including the following steps: S1. Sodium dimethyl isophthalate-5-sulfonate, the quaternized polyether with hydroxyl-terminated ends prepared in Example 1, and dibutyltin oxide were mixed and reacted at 200°C for 3 hours under nitrogen protection to obtain a prepolymer. Bio-based polyamide 56, caprolactam, and antimony trioxide were added to the prepolymer, and the mixture was reacted at 240°C for 2 hours under nitrogen protection and a pressure of 2 MPa. After the reaction was completed, the temperature was lowered to below 200°C, and triphenyl phosphate was added. The mixture was then reacted at 255°C for 4 hours under a pressure of <100 Pa. After completion, the material was discharged to obtain a copolymerized modified polyamide; wherein, the mass ratio of sodium dimethyl isophthalate-5-sulfonate, hydroxyl-terminated quaternized polyether, bio-based polyamide 56, and caprolactam was 10:18:78:27, the amount of dibutyltin oxide added was 0.3% of the total mass of sodium dimethyl isophthalate-5-sulfonate and hydroxyl-terminated quaternized polyether, the amount of antimony trioxide added was 0.08% of the total mass of bio-based polyamide 56 and caprolactam, and the amount of triphenyl phosphate added was 0.2% of the total mass of bio-based polyamide 56 and caprolactam; S2. The copolymerized modified polyamide is melt-spun, wound, drawn, and heat-set to obtain the modified nylon filament; wherein the spinning temperature is 265℃, the winding speed is 4000m / min, the drawing temperature is 75℃, the drawing ratio is 3.2 times, and the heat-setting temperature is 115℃; the single fiber fineness of the modified nylon filament is 2.5dtex.

[0022] Example 5 This embodiment provides a method for preparing a bio-based moisture-wicking fabric, including the following steps: Step 1: The modified nylon filament obtained in Example 2 is spun together with spandex filament to obtain nylon / spandex composite yarn; wherein, the nylon / spandex composite yarn is a covered yarn formed by covering the modified nylon filament with the spandex filament; the mass ratio of the modified nylon filament to the spandex filament is 90:10; the covering process includes: S-twist, 500 twists, and spandex draw ratio of 2 times; Step 2: Using a weft-knitting circular knitting machine, the nylon / spandex composite yarn is used as the first yarn, and the modified nylon filament obtained in Example 2 is used as the second yarn. The first and second yarns are fed in simultaneously through a yarn feeder, and a bio-based moisture-wicking fabric is obtained through a knitting process. The bio-based moisture-wicking fabric has a three-layer composite structure: an inner layer, a middle layer, and an outer layer. The inner layer is formed by knitting the first yarn with a padded weave, the outer layer is formed by knitting the first yarn with a weft plain knit, and the middle layer is formed by knitting the second yarn with a tuck weave. The tuck loops of the tuck weave are divided into... Do not connect with the inner and outer layer loops; the middle layer's tufting structure adopts a three-way knitting structure, specifically: the first way tufts on odd-numbered needles and forms loops on even-numbered needles, the second way forms loops on odd-numbered needles and tufts on even-numbered needles, and the third way forms loops on all needles; the ratio of the tufting loop length to the loop length is 0.4:1; the circular knitting machine has a cylinder diameter of 30 inches, a needle size of 24G, a rotation speed of 15 r / min, a first yarn feed tension of 3 cN, and a second yarn feed tension of 2 cN; the bio-based moisture-wicking fabric has a weight of 170 g / m². 2 .

[0023] Example 6 This embodiment provides a method for preparing a bio-based moisture-wicking fabric, including the following steps: Step 1: The modified nylon filament obtained in Example 3 is spun together with spandex filament to obtain nylon / spandex composite yarn; wherein, the nylon / spandex composite yarn is a covered yarn formed by covering the modified nylon filament with the spandex filament; the mass ratio of the modified nylon filament to the spandex filament is 82:18; the covering process includes: S-twist, 800 twists, and spandex draw ratio of 3.5 times; Step 2: Using a weft-knitting circular knitting machine, the nylon / spandex composite yarn is used as the first yarn, and the modified nylon filament obtained in Example 3 is used as the second yarn. The first and second yarns are fed in simultaneously through a yarn feeder, and a bio-based moisture-wicking fabric is obtained through a knitting process. The bio-based moisture-wicking fabric has a three-layer composite structure: an inner layer, a middle layer, and an outer layer. The inner layer is formed by knitting the first yarn with a padded weave, the outer layer is formed by knitting the first yarn with a plain weave, and the middle layer is formed by knitting the second yarn with a tuck weave. The tuck loops of the tuck weave are divided into... Do not connect with the inner and outer layer coils; the middle layer's tufting structure adopts a three-way knitting structure, specifically: the first way tufts on odd-numbered needles and forms loops on even-numbered needles, the second way forms loops on odd-numbered needles and tufts on even-numbered needles, and the third way forms loops on all needles; the ratio of the tufting loop length to the loop length is 0.6:1; the circular knitting machine has a cylinder diameter of 38 inches, a needle size of 32G, a rotation speed of 22 r / min, a first yarn feed tension of 6 cN, and a second yarn feed tension of 4 cN; the bio-based moisture-wicking fabric has a weight of 150 g / m². 2 .

[0024] Example 7 This embodiment provides a method for preparing a bio-based moisture-wicking fabric, including the following steps: Step 1: The modified nylon filament obtained in Example 4 is spun together with spandex filament to obtain nylon / spandex composite yarn; wherein, the nylon / spandex composite yarn is a covered yarn formed by covering the modified nylon filament with the spandex filament; the mass ratio of the modified nylon filament to the spandex filament is 86:14; the covering process includes: S-twist, 650 twists, and spandex draw ratio of 2.8 times; Step 2: Using a weft-knitting circular knitting machine, the nylon / spandex composite yarn is used as the first yarn, and the modified nylon filament obtained in Example 4 is used as the second yarn. The first and second yarns are fed in simultaneously through a yarn feeder, and a bio-based moisture-wicking fabric is obtained through a knitting process. The bio-based moisture-wicking fabric has a three-layer composite structure: an inner layer, a middle layer, and an outer layer. The inner layer is formed by knitting the first yarn with a padded weave, the outer layer is formed by knitting the first yarn with a plain weave, and the middle layer is formed by knitting the second yarn with a tuck weave. The tuck loops of the tuck weave are divided into... Do not connect with the inner and outer layer coils; the middle layer's tucked structure adopts a three-way knitting structure, specifically: the first way tucks on odd-numbered needles and forms loops on even-numbered needles, the second way forms loops on odd-numbered needles and tucks on even-numbered needles, and the third way forms loops on all needles; the ratio of the tucked loop length to the loop length is 0.5:1; the circular knitting machine has a cylinder diameter of 38 inches, a needle size of 34G, a rotation speed of 18 r / min, a first yarn feed tension of 5 cN, and a second yarn feed tension of 3 cN; the bio-based moisture-wicking fabric has a weight of 160 g / m². 2 .

[0025] Comparative Example 1 This comparative example provides a method for preparing modified nylon filament, including the following steps: S1. Sodium dimethyl isophthalate-5-sulfonate, polyethylene glycol 400, and dibutyltin oxide were mixed and reacted at 220°C for 2 hours under nitrogen protection to obtain a prepolymer. Bio-based polyamide 56, caprolactam, and antimony trioxide were added to the prepolymer, and the mixture was reacted at 255°C for 1.5 hours under nitrogen protection and a pressure of 2.2 MPa. After the reaction was completed, the temperature was lowered to below 200°C, and triphenyl phosphate was added. The mixture was then reacted at 270°C for 3 hours under a pressure of <100 Pa. After completion, the material was discharged to obtain a copolymerized modified polyamide; wherein, the mass ratio of sodium dimethyl isophthalate-5-sulfonate, polyethylene glycol 400, bio-based polyamide 56, and caprolactam was 5:6.6:85:15, the amount of dibutyltin oxide added was 0.5% of the total mass of sodium dimethyl isophthalate-5-sulfonate and polyethylene glycol 400, the amount of antimony trioxide added was 0.1% of the total mass of bio-based polyamide 56 and caprolactam, and the amount of triphenyl phosphate added was 0.3% of the total mass of bio-based polyamide 56 and caprolactam; S2. The copolymerized modified polyamide is melt-spun, wound, drawn, and heat-set to obtain the modified nylon filament; wherein the spinning temperature is 280℃, the winding speed is 4500m / min, the drawing temperature is 90℃, the drawing ratio is 4 times, and the heat-setting temperature is 130℃; the single fiber fineness of the modified nylon filament is 1.8dtex.

[0026] Comparative Example 2 This comparative example provides a method for preparing modified nylon filament, including the following steps: S1. Dimethyl isophthalate, the quaternized polyether with hydroxyl-terminated ends prepared in Example 1, and dibutyltin oxide were mixed and reacted at 220°C for 2 hours under nitrogen protection to obtain a prepolymer. Bio-based polyamide 56, caprolactam, and antimony trioxide were added to the prepolymer, and the mixture was reacted at 255°C for 1.5 hours under nitrogen protection and at a pressure of 2.2 MPa. After the reaction was completed, the temperature was lowered to below 200°C, and triphenyl phosphate was added. The mixture was then reacted at 270°C under a pressure of <100 Pa. The reaction was carried out at a certain temperature for 3 hours. After the reaction was completed, the product was discharged to obtain a copolymerized modified polyamide. The mass ratio of dimethyl isophthalate, hydroxyl-terminated quaternized polyether, bio-based polyamide 56, and caprolactam was 3.3:10:85:15. The amount of dibutyltin oxide added was 0.5% of the total mass of the hydroxyl-terminated quaternized polyether, the amount of antimony trioxide added was 0.1% of the total mass of the bio-based polyamide 56 and caprolactam, and the amount of triphenyl phosphate added was 0.3% of the total mass of the bio-based polyamide 56 and caprolactam. S2. The copolymerized modified polyamide is melt-spun, wound, drawn, and heat-set to obtain the modified nylon filament; wherein the spinning temperature is 280℃, the winding speed is 4500m / min, the drawing temperature is 90℃, the drawing ratio is 4 times, and the heat-setting temperature is 130℃; the single fiber fineness of the modified nylon filament is 1.8dtex.

[0027] Comparative Example 3 This comparative example provides a method for preparing a bio-based moisture-wicking fabric, including the following steps: Step 1: The modified nylon filament obtained in Comparative Example 1 is spun together with spandex filament to obtain nylon / spandex composite yarn; wherein, the nylon / spandex composite yarn is a covered yarn formed by covering the modified nylon filament with the spandex filament; the mass ratio of the modified nylon filament to the spandex filament is 82:18; the covering process includes: S-twist, 800 twists, and spandex draw ratio of 3.5 times; Step 2: Using a weft-knitting circular knitting machine, the nylon / spandex composite yarn is used as the first yarn, and the modified nylon filament obtained in Example 3 is used as the second yarn. The first and second yarns are fed in simultaneously through a yarn feeder, and a bio-based moisture-wicking fabric is obtained through a knitting process. The bio-based moisture-wicking fabric has a three-layer composite structure: an inner layer, a middle layer, and an outer layer. The inner layer is formed by knitting the first yarn with a padded weave, the outer layer is formed by knitting the first yarn with a plain weave, and the middle layer is formed by knitting the second yarn with a tuck weave. The tuck loops of the tuck weave are divided into... Do not connect with the inner and outer layer coils; the middle layer's tufting structure adopts a three-way knitting structure, specifically: the first way tufts on odd-numbered needles and forms loops on even-numbered needles, the second way forms loops on odd-numbered needles and tufts on even-numbered needles, and the third way forms loops on all needles; the ratio of the tufting loop length to the loop length is 0.6:1; the circular knitting machine has a cylinder diameter of 38 inches, a needle size of 32G, a rotation speed of 22 r / min, a first yarn feed tension of 6 cN, and a second yarn feed tension of 4 cN; the bio-based moisture-wicking fabric has a weight of 150 g / m². 2 .

[0028] Comparative Example 4 This comparative example provides a method for preparing a bio-based moisture-wicking fabric, including the following steps: Step 1: The modified nylon filament obtained in Comparative Example 2 is spun together with spandex filament to obtain nylon / spandex composite yarn; wherein, the nylon / spandex composite yarn is a covered yarn formed by covering the modified nylon filament with the spandex filament; the mass ratio of the modified nylon filament to the spandex filament is 82:18; the covering process includes: S-twist, 800 twists, and spandex draw ratio of 3.5 times; Step 2: Using a weft-knitting circular knitting machine, the nylon / spandex composite yarn is used as the first yarn, and the modified nylon filament obtained in Example 3 is used as the second yarn. The first and second yarns are fed in simultaneously through a yarn feeder, and a bio-based moisture-wicking fabric is obtained through a knitting process. The bio-based moisture-wicking fabric has a three-layer composite structure: an inner layer, a middle layer, and an outer layer. The inner layer is formed by knitting the first yarn with a padded weave, the outer layer is formed by knitting the first yarn with a plain weave, and the middle layer is formed by knitting the second yarn with a tuck weave. The tuck loops of the tuck weave are divided into... Do not connect with the inner and outer layer coils; the middle layer's tufting structure adopts a three-way knitting structure, specifically: the first way tufts on odd-numbered needles and forms loops on even-numbered needles, the second way forms loops on odd-numbered needles and tufts on even-numbered needles, and the third way forms loops on all needles; the ratio of the tufting loop length to the loop length is 0.6:1; the circular knitting machine has a cylinder diameter of 38 inches, a needle size of 32G, a rotation speed of 22 r / min, a first yarn feed tension of 6 cN, and a second yarn feed tension of 4 cN; the bio-based moisture-wicking fabric has a weight of 150 g / m². 2 .

[0029] Comparative Example 5 This comparative example provides a method for preparing a bio-based moisture-wicking fabric, including the following steps: Step 1: The modified nylon filament obtained in Example 3 is spun together with spandex filament to obtain nylon / spandex composite yarn; wherein, the nylon / spandex composite yarn is a covered yarn formed by covering the modified nylon filament with the spandex filament; the mass ratio of the modified nylon filament to the spandex filament is 82:18; the covering process includes: S-twist, 800 twists, and spandex draw ratio of 3.5 times; Step 2: Using a weft-knitting circular knitting machine, the nylon / spandex composite yarn is fed in through a yarn feeder and knitted using a double-sided plain knit structure to obtain a bio-based moisture-wicking fabric. The circular knitting machine has a cylinder diameter of 38 inches, a needle gauge of 32G, a rotation speed of 22 r / min, and a yarn tension of 6 cN. The bio-based moisture-wicking fabric has a weight of 150 g / m².

[0030] Performance testing: (1) Measurement of moisture absorption and wicking properties: Referring to standard GB / T21655.1-2023 "Evaluation of moisture absorption and quick-drying properties of textiles - Part 1: Single-item combination test method", the water absorption rate, water droplet diffusion time, wicking height and drying rate of the bio-based moisture-wicking fabric samples prepared in Examples 5-7 and Comparative Examples 3-5 were measured. The results are shown in Table 1:

[0031] As shown in Table 1, the fabric prepared by this invention has good moisture absorption and wicking properties. Compared with Example 5: In Comparative Example 3, polyethylene glycol 400 was used to replace the double-terminated hydroxyl quaternized polyether when preparing the modified nylon filament. Although the quaternization treatment was missing, the hydrophilic polyether segments and sulfonic acid groups could still work synergistically, so the moisture absorption and wicking properties of the fabric only decreased slightly; In Comparative Example 4, no sulfonic acid groups were introduced when preparing the modified nylon filament, and the hydrophilicity of the modified nylon filament decreased, resulting in a significant reduction in the moisture absorption and wicking properties of the fabric; In Comparative Example 5, ordinary double-sided plain knit weave was used to replace the three-layer composite structure. Since the same modified nylon filament as in Example 6 was used, the fiber hydrophilicity was the same, and the water absorption rate was comparable to that of Example 6. However, the wicking height and drying rate decreased significantly, and the drip diffusion time was prolonged, proving that the three-layer composite structure has a significant enhancing effect on the rapid conduction and evaporation of sweat.

[0032] (2) Antibacterial performance test: Referring to standard GB / T20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Shaking method", the inhibition rate of the bio-based moisture-wicking fabric samples prepared in Examples 5-7 and Comparative Examples 3-5 against Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 8099) was determined. The results of the antibacterial rate test are shown in Table 2.

[0033] As shown in Table 2, the fabric prepared by this invention has excellent antibacterial properties. Compared with Example 5: In Comparative Example 3, polyethylene glycol 400 was used to replace the double-terminated hydroxyl quaternized polyether when preparing the modified nylon filament, resulting in the absence of quaternary ammonium salt groups and a sharp decrease in antibacterial properties; in Comparative Example 4, no sulfonic acid groups were introduced when preparing the modified nylon filament, so there was no significant impact on the antibacterial properties of the fabric; in Comparative Example 5, ordinary double-sided plain knit weave was used to replace the three-layer composite structure, which also had no significant impact on the antibacterial properties of the fabric.

[0034] (3) Antistatic performance test: Referring to standard GB / T12703.1-2008 "Evaluation of electrostatic properties of textiles - Part 1: Static voltage half-life", the antistatic properties of the bio-based moisture-wicking fabric samples prepared in Examples 5-7 and Comparative Examples 3-5 were measured. The test results are shown in Table 3.

[0035] As shown in Table 3, the fabric prepared by this invention has excellent antistatic properties. Compared with Example 5: In Comparative Example 3, the use of polyethylene glycol 400 to replace the double-terminated hydroxyl quaternized polyether in the preparation of modified nylon filaments significantly reduced the antistatic properties; in Comparative Example 4, the absence of sulfonic acid groups in the preparation of modified nylon filaments also significantly reduced the antistatic properties; in Comparative Example 5, the use of ordinary double-sided plain knit weave to replace the three-layer composite structure had no significant impact on the antistatic properties of the fabric.

[0036] (4) One-way moisture wicking performance test: Referring to the standard FTTS-FA-004 "Specification for testing the moisture absorption, wicking, quick-drying and one-way moisture transfer performance of fabrics", the one-way moisture wicking performance of the bio-based moisture-wicking fabric samples prepared in Examples 5-7 and Comparative Examples 3-5 was measured. The test results are shown in Table 4:

[0037] As shown in Table 4, the fabric prepared by this invention has good unidirectional moisture-wicking properties. Compared with Example 5: In Comparative Example 3, the fabric is based on the modified nylon filament in Comparative Example 1: sulfonic acid groups and polyether segments are retained, only the quaternization treatment is missing, which does not significantly affect the unidirectional moisture-wicking properties of the fabric; In Comparative Example 4, the unidirectional transfer index of the fabric decreases, the inner layer wetting time increases, the outer layer absorption rate increases, and the maximum wetting radius decreases, indicating that sulfonic acid groups are an important factor in forming a wetting gradient. The absence of sulfonic acid groups leads to a decrease in the overall hydrophilicity of the fiber, which cannot effectively drive the unidirectional conduction of sweat; In Comparative Example 5, a common double-sided plain knit weave is used to replace the three-layer composite structure of this invention. Its unidirectional transfer index decreases significantly, the difference between the inner and outer layer wetting times is not significant, the absorption rates of the inner and outer layers are similar, and the maximum wetting radius is the same for the inner and outer layers. This indicates that the common fabric structure cannot form an effective unidirectional conduction gradient, and sweat easily accumulates in the outer layer and then seeps back, resulting in a damp and cold feeling. Even if the fiber modification is complete, the moisture-wicking effect of this invention cannot be achieved.

[0038] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a bio-based moisture-wicking fabric, characterized in that, Includes the following steps: Step 1: The modified nylon filament and spandex filament are composite spun to obtain nylon / spandex composite yarn; wherein, the modified nylon filament is obtained by melt spinning of a copolymer modified polyamide prepared by reacting bio-based polyamide 56, caprolactam, sodium dimethyl isophthalate-5-sulfonate and double-hydroxyl-terminated quaternized polyether. Step 2: Using a weft-knitting circular knitting machine, the nylon / spandex composite yarn is used as the first yarn, and the modified nylon filament is used as the second yarn. The first and second yarns are fed in simultaneously through a yarn feeder, and a bio-based moisture-wicking fabric is obtained through a knitting process. The bio-based moisture-wicking fabric has a three-layer composite structure: an inner layer, a middle layer, and an outer layer. The inner layer is formed by knitting the first yarn with a padded weave, the outer layer is formed by knitting the first yarn with a plain weave, and the middle layer is formed by knitting the second yarn with a tuck weave. The tuck loops of the tuck weave are connected to the loops of the inner layer and the outer layer, respectively.

2. The method for preparing a bio-based moisture-wicking fabric according to claim 1, characterized in that, The nylon / spandex composite yarn in step one is a covered yarn formed by covering the modified nylon filament with the spandex filament; The mass ratio of the modified nylon filament to the spandex filament is (82-90):(10-18). The coating process includes: S-twist, 500-800 twists, and spandex draw ratio of 2-3.5 times.

3. The method for preparing a bio-based moisture-wicking fabric according to claim 1, characterized in that, The preparation method of the modified nylon filament in step one specifically includes the following steps: S1. Sodium dimethyl isophthalate-5-sulfonate, bi-hydroxyl-terminated quaternized polyether and catalyst 1 are mixed and reacted to obtain a prepolymer. Bio-based polyamide 56, caprolactam and catalyst 2 are added to the prepolymer and the reaction continues. After the reaction is completed, the temperature is lowered, a stabilizer is added, and the reaction is repeated. After the reaction is completed, the product is discharged to obtain the copolymerized modified polyamide. S2. The copolymerized polyamide is melt-spun, wound, drawn, and heat-set to obtain the modified nylon filament.

4. The method for preparing a bio-based moisture-wicking fabric according to claim 3, characterized in that, In S1, the mass ratio of sodium dimethyl isophthalate-5-sulfonate, dihydroxylated quaternized polyether, bio-based polyamide 56, and caprolactam is (5-15):(10-25):(70-85):(15-30). The amount of catalyst 1 added is 0.1%-0.5% of the total mass of sodium dimethyl isophthalate-5-sulfonate and dihydroxylated quaternized polyether, and the amount of catalyst 2 added is 0.05%-0.1% of the total mass of bio-based polyamide 56 and caprolactam. The amount of stabilizer added is 0.1%-0.3% of the total mass of bio-based polyamide 56 and caprolactam; the reaction conditions are as follows: under nitrogen protection, at a temperature of 180-220℃ for 2-4 hours; the conditions for continued reaction are under nitrogen protection, at a pressure of 1.8-2.2 MPa, at a temperature of 230-255℃ for 1.5-2.5 hours; and the conditions for a second reaction are under a pressure of <100 Pa, at a temperature of 240-270℃ for 3-5 hours.

5. The method for preparing a bio-based moisture-wicking fabric according to claim 4, characterized in that, The catalyst 1 comprises dibutyltin oxide, the catalyst 2 comprises antimony trioxide, and the stabilizer comprises triphenyl phosphate.

6. The method for preparing a bio-based moisture-wicking fabric according to claim 4, characterized in that, The double-hydroxyl-terminated quaternized polyether is prepared by the following steps: Step (1): Mix polyethylene glycol and epichlorohydrin at a molar ratio of 1:(2-2.5), add 0.5-2% of tin tetrachloride / trichloroacetic acid mixed catalyst by mass of polyethylene glycol, and react at 30-60℃ for 6-12h to obtain double-hydroxyl-terminated polyether; Step (2): Heat the bihydroxyl-terminated polyether to a set temperature, and add a 30-50% (w / w) triethylamine aqueous solution. The amount of triethylamine added is 1-1.2 times the molar amount of epichlorohydrin. React at the set temperature for 4-8 hours. After the reaction is complete, purify to obtain the bihydroxyl-terminated quaternized polyether. The set temperature is 60-90℃.

7. The method for preparing a bio-based moisture-wicking fabric according to claim 3, characterized in that, In S2, the spinning temperature is 250-280℃, the winding speed is 3000-4500m / min, the drawing temperature is 60-90℃, the drawing ratio is 2.5-4 times, and the heat setting temperature is 100-130℃.

8. The method for preparing a bio-based moisture-wicking fabric according to claim 1, characterized in that, In step two, the cylinder diameter of the weft knitting circular knitting machine is 30-38 inches, the needle size is 24-32G, and the rotation speed is 15-22 r / min; the feeding tension of the first yarn is 3-6 cN, and the feeding tension of the second yarn is 2-4 cN.

9. The method for preparing a bio-based moisture-wicking fabric according to claim 1, characterized in that, In step two, the tufting structure of the middle layer adopts a three-way knitting structure. The first way is to tuck the odd-numbered needles and form loops on the even-numbered needles. The second way is to form loops on the odd-numbered needles and tuck the even-numbered needles. The third way is to form loops on all needles. The ratio of the tufting loop length to the loop length is (0.4-0.6):

1.

10. A bio-based moisture-wicking fabric prepared by the method described in any one of claims 1-9.

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