Deodorizing bio-based wool blended yarn and preparation method thereof

Abstract

The invention provides a deodorant bio-based wool blended yarn and a preparation method thereof, and belongs to the technical field of blended yarns. The deodorization bio-based wool blended yarn is prepared by modifying and assembling three bio-based materials; the method comprises the following steps: performing surface reconstruction on hemp fibers by using ionic liquid, and converting rigid surfaces of the hemp fibers into permanently soft and high-moisture-absorption structures; a tea polyphenol in-situ polymerization technology is adopted, so that a layer of durable anti-oxidation and odor-resistant nano coating is connected to the wool fiber; the preparation method comprises the following steps: physically locking antibacterial chitosan in an alginate network by adopting a wet spinning technology to prepare a non-dissolution functional core yarn; the three components are precisely combined through a core spinning technology to form a synergistic core-shell structure, a shell is responsible for resisting oxidation from the source and creating a dry and bacteriostatic microenvironment, and a core actively kills bacteria and performs humidity management, so that coexistence of comfort, lasting functionality and sustainability is realized.

Description

Technical Field

[0001] This invention belongs to the field of blended yarn technology, and relates to an odor-resistant bio-based wool blended yarn and its preparation method. Background Technology

[0002] Currently, several challenges remain in developing high-performance bio-based blended yarns. Firstly, there is the inherent contradiction between the comfort and performance of natural fibers. Take hemp fiber as an example: while it is an ideal sustainable raw material with natural antibacterial properties and high moisture permeability, its cellulose I crystal form leads to rigidity, a rough feel, and poor spinnability, hindering its application in high-end skin-friendly products. Traditional methods of modification using strong alkalis or high-temperature cooking not only damage fiber strength but also generate large amounts of difficult-to-treat wastewater; while conventional bio-enzyme treatments often suffer from incomplete results and high costs, failing to fundamentally address its comfort shortcomings.

[0003] Secondly, there are issues with the poor durability of the functions and potential environmental safety hazards. The odor-resistant properties of fibers like wool are often achieved through modification. However, mainstream finishing agents, such as heavy metal antibacterial agents like silver and copper ions, pose a risk of bioaccumulation and potential ecotoxicity; quaternary ammonium salt antibacterial agents suffer from poor wash fastness, and their functionality diminishes with repeated washing. Furthermore, these functional finishes are typically single-effect; achieving multiple functions simultaneously, such as UV protection and antioxidant properties, often requires multi-step, complex chemical treatments. This not only increases production costs but also contradicts the principles of green manufacturing. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an odor-resistant bio-based wool blend yarn and its preparation method. This application prepares an odor-resistant bio-based wool blend yarn by modifying and assembling three bio-based materials. First, ionic liquids are used to reconstruct the surface of hemp fibers, transforming their rigid surface into a permanently soft and highly hygroscopic structure. Simultaneously, a durable antioxidant and odor-resistant nano-coating is applied to the wool fibers using in-situ polymerization of tea polyphenols. Next, wet spinning technology is employed to physically lock antibacterial chitosan within an alginate network, creating a non-leaching functional core filament. Finally, core spinning technology precisely combines these three elements to form a synergistic core-shell structure: the outer shell is responsible for anti-oxidation from the source and creating a dry and antibacterial microenvironment, while the core actively kills bacteria and manages humidity, thereby achieving a coexistence of comfort, durable functionality, and sustainability.

[0005] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing odor-resistant bio-based wool blended yarn, the method comprising: S1: Soak hemp fibers in deionized water and dry them to obtain pretreated hemp fibers; add them to the ionic liquid [Bmim]Cl and stir to obtain reaction solution A; mix reaction solution A with deionized water and stir, filter, wash and dry to obtain modified hemp fibers; S2: Prepare a Tris-HCl solution and adjust the pH value to obtain a Tris-HCl buffer solution; soak wool fibers in the Tris-HCl buffer solution to obtain reaction solution B, add tea polyphenols to obtain reaction solution C, stir the reaction, filter, wash and dry to obtain modified wool fibers; S3: Sodium alginate is added to deionized water, stirred, and allowed to stand to obtain a sodium alginate solution; chitosan is added to an aqueous acetic acid solution, stirred, and allowed to stand to obtain a chitosan solution; the chitosan solution is added to the sodium alginate solution, mixed evenly, and vacuum degassed to obtain a mixed spinning solution; the mixed spinning solution is loaded into an injection pump, and the resulting fine stream is injected through a coagulation solution to obtain nascent fibers; the nascent fibers undergo a first stretching in the coagulation solution and a second stretching in water to obtain pretreated composite filaments; subsequently, after washing, oiling, and drying, alginate / chitosan composite filaments are obtained. S4: Mix modified hemp fiber and modified wool fiber, open, comb, and draw to obtain fiber sliver, and use a ring spinning device to spin the fiber sliver and alginate / chitosan composite filament to obtain odor-resistant bio-based wool blended yarn.

[0006] As a preferred technical solution of the present invention, in step S1, the length of the hemp fiber is 30-50mm, for example, it can be 30mm, 32mm, 34mm, 36mm, 38mm, 40mm, 42mm, 44mm, 46mm, 48mm or 50mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0007] In some alternative embodiments, the fineness of the hemp fiber is 5-15 dtex, for example, it can be 5 dtex, 6 dtex, 7 dtex, 8 dtex, 9 dtex, 10 dtex, 11 dtex, 12 dtex, 13 dtex, 14 dtex or 15 dtex, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0008] In some alternative embodiments, the hemp fibers are soaked in deionized water at a temperature of 60-80°C, such as 60°C, 62°C, 64°C, 66°C, 68°C, 70°C, 72°C, 74°C, 76°C, 78°C or 80°C, but not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0009] In some alternative embodiments, the hemp fibers are soaked in deionized water for 0.5-1 hour, for example, 0.50 hours, 0.55 hours, 0.60 hours, 0.65 hours, 0.70 hours, 0.75 hours, 0.80 hours, 0.85 hours, 0.90 hours, 0.95 hours, or 1.00 hours, but are not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0010] In some alternative embodiments, the temperature at which the pretreated hemp fibers are added to the ionic liquid [Bmim]Cl and stirred is 90-110°C, for example, 90°C, 92°C, 94°C, 96°C, 98°C, 100°C, 102°C, 104°C, 106°C, 108°C, or 110°C, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0011] In some optional embodiments, the pretreated hemp fibers are added to the ionic liquid [Bmim]Cl and stirred at a speed of 100-200 rpm, for example, 100 rpm, 110 rpm, 120 rpm, 130 rpm, 140 rpm, 150 rpm, 160 rpm, 170 rpm, 180 rpm, 190 rpm or 200 rpm, but not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0012] In some alternative embodiments, the pretreated hemp fibers are added to the ionic liquid [Bmim]Cl and stirred for 3-8 minutes, for example, 3.0 minutes, 3.5 minutes, 4.0 minutes, 4.5 minutes, 5.0 minutes, 5.5 minutes, 6.0 minutes, 6.5 minutes, 7.0 minutes, 7.5 minutes, or 8.0 minutes, but not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0013] In some optional embodiments, the mass ratio of the pretreated hemp fiber to the ionic liquid is 1:(20-50), for example, 1:20, 1:23, 1:26, 1:29, 1:32, 1:35, 1:38, 1:41, 1:44, 1:47 or 1:50, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0014] In some optional embodiments, the volume ratio of the reaction solution A to deionized water is 1:(5-10), for example, it can be 1:5.0, 1:5.5, 1:6.0, 1:6.5, 1:7.0, 1:7.5, 1:8.0, 1:8.5, 1:9.0, 1:9.5 or 1:10.0, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0015] The washing process involves alternating between hot and cold water until no AgCl precipitate is detected in the washing solution using a 0.1M silver nitrate solution.

[0016] In some optional embodiments, the temperature of the hot water used for washing is 60-70°C, for example, it can be 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0017] As a preferred technical solution of the present invention, in step S2, the concentration of the Tris-HCl solution is 30-70mM, for example, it can be 30mM, 34mM, 38mM, 42mM, 46mM, 50mM, 54mM, 58mM, 62mM, 66mM or 70mM, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0018] In some alternative embodiments, the pH of the Tris-HCl buffer solution is 8-9, for example, it may be 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9 or 9.0, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0019] In some alternative embodiments, the diameter of the wool fiber is 18.5-20.5 μm, for example, it can be 18.5 μm, 18.7 μm, 18.9 μm, 19.1 μm, 19.3 μm, 19.5 μm, 19.7 μm, 19.9 μm, 20.1 μm, 20.3 μm or 20.5 μm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0020] In some alternative embodiments, the length of the wool fiber is 50-70 mm, for example, it can be 50 mm, 52 mm, 54 mm, 56 mm, 58 mm, 60 mm, 62 mm, 64 mm, 66 mm, 68 mm or 70 mm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0021] In some optional embodiments, the mass-to-volume ratio of the wool fiber to the Tris-HCl buffer solution is 1 g:(30-50) mL, for example, it can be 1 g:30 mL, 1 g:32 mL, 1 g:34 mL, 1 g:36 mL, 1 g:38 mL, 1 g:40 mL, 1 g:42 mL, 1 g:44 mL, 1 g:46 mL, 1 g:48 mL or 1 g:50 mL, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0022] In some optional embodiments, the concentration of tea polyphenols in reaction solution C is 1-4 g / L, for example, it can be 1.0 g / L, 1.3 g / L, 1.6 g / L, 1.9 g / L, 2.2 g / L, 2.5 g / L, 2.8 g / L, 3.1 g / L, 3.4 g / L, 3.7 g / L or 4.0 g / L, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0023] In some optional embodiments, the reaction mixture C is stirred at a speed of 50-100 rpm, for example, 50 rpm, 55 rpm, 60 rpm, 65 rpm, 70 rpm, 75 rpm, 80 rpm, 85 rpm, 90 rpm, 95 rpm or 100 rpm, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0024] In some optional embodiments, the reaction time of the reaction solution C is 8-12 hours, for example, 8.0 hours, 8.4 hours, 8.8 hours, 9.2 hours, 9.6 hours, 10.0 hours, 10.4 hours, 10.8 hours, 11.2 hours, 11.6 hours or 12.0 hours, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0025] As a preferred technical solution of the present invention, in step S3, the sodium alginate is added to deionized water and stirred for 2-4 hours, for example, 2.0h, 2.2h, 2.4h, 2.6h, 2.8h, 3.0h, 3.2h, 3.4h, 3.6h, 3.8h or 4.0h, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0026] In some optional embodiments, the sodium alginate is added to deionized water and allowed to stand for 16-20 hours after stirring. For example, it can be 16.0 hours, 16.4 hours, 16.8 hours, 17.2 hours, 17.6 hours, 18.0 hours, 18.4 hours, 18.8 hours, 19.2 hours, 19.6 hours, or 20.0 hours, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0027] In some optional embodiments, the sodium alginate solution has a mass fraction of 4-8 wt.%, for example, 4.0 wt.%, 4.4 wt.%, 4.8 wt.%, 5.2 wt.%, 5.6 wt.%, 6.0 wt.%, 6.4 wt.%, 6.8 wt.%, 7.2 wt.%, 7.6 wt.%, or 8.0 wt.%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0028] In some alternative embodiments, the concentration of the aqueous acetic acid solution is 1-2%, for example, it may be 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2.0%, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0029] In some optional embodiments, the chitosan is added to the aqueous acetic acid solution and stirred for 3-6 hours, for example, 3.0 hours, 3.3 hours, 3.6 hours, 3.9 hours, 4.2 hours, 4.5 hours, 4.8 hours, 5.1 hours, 5.4 hours, 5.7 hours, or 6.0 hours, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0030] In some optional embodiments, the chitosan solution has a mass fraction of 2-4 wt.%, for example, 2.0 wt.%, 2.2 wt.%, 2.4 wt.%, 2.6 wt.%, 2.8 wt.%, 3.0 wt.%, 3.2 wt.%, 3.4 wt.%, 3.6 wt.%, 3.8 wt.%, or 4.0 wt.%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0031] In some optional embodiments, the mass ratio of sodium alginate to chitosan in the mixed spinning solution is (80-90):(20-10), for example, it can be 80:20, 81:19, 82:18, 83:17, 84:16, 85:15, 86:14, 87:13, 88:12, 89:11 or 90:10, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0032] In some optional embodiments, the injection rate of the syringe pump is 0.1-0.5 mL / min, for example, 0.10 mL / min, 0.14 mL / min, 0.18 mL / min, 0.22 mL / min, 0.26 mL / min, 0.30 mL / min, 0.34 mL / min, 0.38 mL / min, 0.42 mL / min, 0.46 mL / min or 0.50 mL / min, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0033] In some optional embodiments, the spinneret orifice of the injection pump is 80-150 μm, for example, it can be 80 μm, 87 μm, 94 μm, 101 μm, 108 μm, 115 μm, 122 μm, 129 μm, 136 μm, 143 μm or 150 μm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0034] In some optional embodiments, the coagulant is an aqueous solution of calcium chloride in ethanol, and the mass fraction of the coagulant is 2-5 wt.%, for example, it can be 2.0 wt.%, 2.3 wt.%, 2.6 wt.%, 2.9 wt.%, 3.2 wt.%, 3.5 wt.%, 3.8 wt.%, 4.1 wt.%, 4.4 wt.%, 4.7 wt.%, or 5.0 wt.%, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0035] In some optional embodiments, the volume ratio of ethanol to water in the coagulation liquid is (30-50):(70-50), for example, it can be 30:70, 32:68, 34:66, 36:64, 38:62, 40:60, 42:58, 44:56, 46:54, 48:52 or 50:50, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0036] In some alternative embodiments, the nascent fibers are subjected to a second stretching in water at 60-80°C, for example, in water at 60°C, 62°C, 64°C, 66°C, 68°C, 70°C, 72°C, 74°C, 76°C, 78°C or 80°C, but not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0037] In some optional embodiments, the first stretching ratio is 1.1-1.5 times, for example, it can be 1.10 times, 1.14 times, 1.18 times, 1.22 times, 1.26 times, 1.30 times, 1.34 times, 1.38 times, 1.42 times, 1.46 times or 1.50 times, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0038] In some optional embodiments, the second stretching ratio is 2-4 times, for example, it can be 2.0 times, 2.2 times, 2.4 times, 2.6 times, 2.8 times, 3.0 times, 3.2 times, 3.4 times, 3.6 times, 3.8 times or 4.0 times, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0039] As a preferred technical solution of the present invention, in step S4, the mass ratio of the modified hemp fiber to the modified wool fiber is (4-6):(6-4), for example, it can be 4:6, 4.2:5.8, 4.4:5.6, 4.6:5.4, 4.8:5.2, 5:5, 5.2:4.8, 5.4:4.6, 5.6:4.4, 5.8:4.2 or 6:4, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0040] The alginate / chitosan composite filament is the core yarn; In some optional embodiments, the alginate / chitosan composite filament accounts for 8-15% by weight in the odor-resistant bio-based wool blended yarn, for example, 8.0%, 8.7%, 9.4%, 10.1%, 10.8%, 11.5%, 12.2%, 12.9%, 13.6%, 14.3%, or 15.0%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0041] Secondly, the present invention provides an odor-resistant bio-based wool blended yarn.

[0042] This application uses hemp fiber, wool fiber, and alginate / chitosan composite filament as the main materials. An odor-resistant bio-based wool blend yarn is obtained by using alginate / chitosan composite filament as the core yarn and coating it with hemp and wool fibers.

[0043] While hemp fiber possesses excellent antibacterial, breathable, and sustainable properties, it also has shortcomings in practical applications that require modification: Firstly, hemp fiber bundles contain a large amount of pectin and lignin, and the cellulose I (natural crystalline form) structure is regular, resulting in high rigidity and poor skin-friendliness; secondly, hemp fibers are stiff and lack cohesion, easily producing fuzz and breakage during spinning. Traditional modification methods (such as strong alkali treatment and bio-enzymatic degumming) more or less have problems such as environmental pollution, damage to the fiber matrix, or incomplete results.

[0044] This application utilizes ionic liquids to alter the surface physical structure of hemp fibers, transforming them from "hard fibers" into "flexible fibers," achieving permanent, structural softening and significantly improving their moisture absorption and wicking properties. The ionic liquid [Bmim]Cl is an organic salt whose chloride ions act as strong hydrogen bond acceptors, effectively disrupting the hydrogen bond network between and within hemp cellulose molecular chains. The cation [Bmim]... + Its large size allows it to insert itself between the opened molecular chains, preventing them from re-aggregating. This process is accelerated under heating conditions of 90-110℃, and "surface sol-plasticization" is achieved by controlling the processing time: that is, only the cellulose on the surface and subsurface of the fiber is dissolved, while the skeletal structure of the fiber core remains intact.

[0045] When the treatment system is poured into a large amount of water, water, as a strongly polar proton solvent, has a much greater affinity for ionic liquids than cellulose. Water molecules rapidly bind to the ionic liquid bound to cellulose, causing the dissolved cellulose molecular chains to lose support and redeposit on the fiber surface. Due to the rapid and disordered precipitation process, the cellulose molecular chains align in a thermodynamically more stable but looser cellulose II crystal form. The natural cellulose I crystal form is parallel and tightly packed, resulting in stiffness. In contrast, the regenerated cellulose II crystal form is antiparallel, with weaker intermolecular forces, making it soft and elastic. This application essentially constructs an in-situ, naturally soft cellulose II structural layer composed of its own substances on stiff hemp fibers. This softness stems from a fundamental change in crystal form, making it permanent and extremely washable. Simultaneously, the regenerated surface forms a nanoscale porous structure, significantly increasing the specific surface area and capillary effect.

[0046] While wool possesses natural antibacterial properties, it can still develop odors under extreme conditions such as excessive sweating. Traditional deodorizing treatments often rely on silver ions and quaternary ammonium salts, which pose risks of bioaccumulation and reduced wash resistance. This application utilizes natural, edible tea polyphenols to "in-situ grow" a multifunctional nano-biofilm on the surface of wool fibers, achieving long-lasting antioxidant deodorization, natural UV protection, and gentle modification of the wool cuticle layer in one step.

[0047] Tea polyphenols are rich in phenolic hydroxyl groups. Under weakly alkaline and aerobic conditions, these hydroxyl groups deprotonate to form phenolic anions, which are readily oxidized to semiquinone radicals and further oxidized to highly reactive quinone structures. These highly reactive quinone structures undergo free radical polymerization or nucleophilic addition reactions, interconnecting to form a polyphenol network, i.e., a nanofilm. Crucially, quinone structures are potent Michael acceptors. Wool keratin is rich in nucleophilic amino and thiol groups, which react with quinone structures through Michael addition or Schiff base reactions to form stable covalent bonds. This allows the polyphenol film to adhere to the wool surface, rather than through simple physical adsorption, resulting in extremely strong wash fastness.

[0048] In this application, alginate / chitosan composite filaments are prepared by wet spinning as the core yarn. Chitosan, as the core antibacterial agent, is firmly physically embedded and ionicly cross-linked in the network framework composed of alginate, achieving non-leaching, long-lasting, and powerful antibacterial function.

[0049] Sodium alginate is a negatively charged polyanion in water, while chitosan is a positively charged polycation in acidic solutions. When mixed, they form a polyelectrolyte complex through electrostatic attraction, laying the foundation for the homogeneity and stability of the spinning solution. When the mixed spinning solution is extruded into a coagulation solution containing divalent calcium ions, a single calcium ion can simultaneously form ionic bonds with the carboxyl groups on two different alginate molecular chains. Countless such "ionic bridges" rapidly crosslink the flowing molecular chains into a three-dimensional network structure, causing the liquid stream to solidify into solid fibers. In this rapidly formed crosslinked network, chitosan molecules are physically embedded and entangled, while their own positive charge attracts the negative charge of alginate, further stabilizing their position in the network. Subsequent hot water drawing utilizes the enhanced mobility of polymer chains at high temperatures. By applying external force, the disordered molecular chains are oriented along the fiber axis, increasing the van der Waals forces between molecules, thereby greatly improving the fiber's breaking strength and modulus.

[0050] Ultimately, a three-dimensional deodorizing system is formed by combining modified hemp fiber, modified wool fiber, and alginate / chitosan composite filaments using core spinning technology. In the outer shell of modified wool fiber, a tea polyphenol coating acts as the first line of defense, preventing the decomposition of organic matter in sweat through antioxidant action, thus inhibiting odor molecules at the source. The modified hemp fiber works synergistically with the modified wool fiber to create a dry, slightly acidic environment unfavorable to bacterial growth. As the final line of defense, the alginate / chitosan composite filaments have distinct components: chitosan exerts a strong, active contact bactericidal effect, eliminating stubborn bacteria that penetrate the outer shell; and alginate absorbs and locks in a large amount of moisture, keeping the skin surface and the inner layer of the fabric dry for a long time.

[0051] Compared with the prior art, the beneficial effects of the present invention are as follows: To address the challenges of rough texture and poor spinnability caused by the rigid cellulose I crystal structure of natural hemp fiber, this application employs ionic liquid surface modification technology. By selectively dissolving the surface layer of hemp fiber with ionic liquids and rapidly regenerating it in water, the cellulose molecular chains are rearranged to form a looser and softer cellulose II crystal structure. This crystal-changing "surface sol-plasticization" method not only permanently endows hemp fiber with an extremely washable and soft structure but also constructs a nanoscale porous surface, thereby enhancing its skin-friendly comfort and moisture absorption and wicking properties. To overcome the environmental risks and functional degradation problems of traditional deodorizing finishing agents, this application utilizes the self-polymerization properties of natural tea polyphenols under weakly alkaline and aerobic conditions. After being oxidized into highly active quinone structures, these polyphenols can not only cross-link to form nanofilms, but also covalently bond with the amino and thiol groups in wool keratin. This "in-situ grown" polyphenol coating, firmly attached to the fiber surface, achieves multiple functions in one step, including durable washability, antioxidant and deodorizing properties, and natural UV protection. This application utilizes wet spinning technology to prepare alginate / chitosan composite filaments, constructing a yarn core with durable and non-leaching antibacterial properties. A uniform spinning solution is formed by the electrostatic attraction between negatively charged sodium alginate and positively charged chitosan. Subsequently, in a coagulation bath containing calcium ions, a stable three-dimensional network structure is formed through rapid ionic cross-linking between calcium ions and alginate molecular chains, causing the liquid to instantly solidify into fibers. During this process, chitosan is physically embedded and locked within the network, ensuring the non-leaching nature of its antibacterial function. Subsequent hot water drawing promotes the axially regular arrangement of the polymer chains, significantly improving the mechanical strength and modulus of the filament. This solution utilizes core-spinning technology to create a synergistic, three-dimensional odor-resistant system. First, the modified wool outer shell, coated with tea polyphenols, acts as the first line of defense, inhibiting odor generation at its source through antioxidant effects. Second, the entire outer shell layer, composed of modified hemp and wool, collaboratively creates a dry, antibacterial microenvironment. Finally, the core filament, serving as the final line of defense, actively contacts and kills bacteria that penetrate the defense, while its alginate component efficiently absorbs and locks in moisture, ensuring lasting dryness and comfort. Detailed Implementation

[0052] The technical solution of the present invention will be described in detail below with reference to specific embodiments. The embodiments described herein are specific implementations of the present invention and are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limiting the implementation of the present invention or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims and the specification of this application. These technical solutions include technical solutions that employ any obvious substitutions and modifications made to the embodiments described herein.

[0053] The chemical reagents used in the embodiments and comparative examples of this invention are all commercially available products and have not undergone further purification or processing.

[0054] Example 1 This embodiment provides an odor-resistant bio-based wool blend yarn and its preparation method. The preparation method of the odor-resistant bio-based wool blend yarn specifically includes the following steps: S1: Soak hemp fibers with a length of 40 mm and a fineness of 10 dtex in deionized water at 75°C for 0.8 h, and dry them to obtain pretreated hemp fibers; add them to the ionic liquid [Bmim]Cl and stir at 105°C and 150 rpm for 6 min to obtain reaction solution A, wherein the mass ratio of pretreated hemp fibers to ionic liquid is 1:30. Mix reaction solution A with deionized water at a volume ratio of 1:8 and stir, filter, wash and dry to obtain modified hemp fibers, wherein the washing is done by alternating between hot water and cold water at 65°C; S2: Prepare a 50mM Tris-HCl solution and adjust the pH to 8.5 to obtain a Tris-HCl buffer solution; immerse wool fibers with a diameter of 19.0μm and a length of 60mm in the Tris-HCl buffer solution to obtain reaction solution B, wherein the mass-to-volume ratio of wool fibers to Tris-HCl buffer solution is 1g:40mL; add tea polyphenols to obtain reaction solution C, wherein the concentration of tea polyphenols in reaction solution C is 3.5g / L; stir at 80rpm for 10h, filter, wash, and dry to obtain modified wool fibers; S3: Sodium alginate was added to deionized water, stirred for 3 hours, and then allowed to stand for 18 hours to obtain a sodium alginate solution with a mass fraction of 6 wt.%; chitosan was added to a 1.5% acetic acid aqueous solution, stirred for 5 hours, and then allowed to stand to obtain a chitosan solution with a mass fraction of 3 wt.%; the chitosan solution was added to the sodium alginate solution, mixed evenly, and vacuum degassed to obtain a mixed spinning solution, wherein the mass ratio of sodium alginate to chitosan in the mixed spinning solution was 85:15; the mixed spinning solution was loaded into an injection pump and injected at a constant rate of 0.3 mL / min. The fine stream obtained by the injection pump is coagulated to obtain nascent fibers. The spinneret of the injection pump has an orifice diameter of 100 μm. The coagulation solution is an ethanol-water solution with a mass fraction of 3 wt.% calcium chloride and a volume ratio of ethanol to water of 40:60. After the nascent fibers are first drawn in the coagulation solution, they are second drawn in water at 70°C to obtain pretreated composite filaments. The first drawing ratio is 1.3 times and the second drawing ratio is 3 times. After washing, oiling, and drying, alginate / chitosan composite filaments are obtained. S4: Modified hemp fiber and modified wool fiber are mixed at a mass ratio of 5:5, opened, combed and drawn to obtain fiber slivers, and the fiber slivers and alginate / chitosan composite filaments are spun using a ring spinning device to obtain odor-resistant bio-based wool blended yarn; wherein the alginate / chitosan composite filaments are the core yarn, accounting for 10% of the weight of the yarn.

[0055] Example 2 This embodiment provides an odor-resistant bio-based wool blend yarn and its preparation method. The preparation method of the odor-resistant bio-based wool blend yarn specifically includes the following steps: S1: Soak hemp fibers with a length of 50 mm and a fineness of 5 dtex in deionized water at 60°C for 1 hour, and dry them to obtain pretreated hemp fibers; add them to the ionic liquid [Bmim]Cl and stir at 90°C and 200 rpm for 3 minutes to obtain reaction solution A, wherein the mass ratio of pretreated hemp fibers to ionic liquid is 1:50. Mix reaction solution A with deionized water at a volume ratio of 1:5 and stir, filter, wash and dry to obtain modified hemp fibers, wherein the washing is done by alternating between hot water and cold water at 70°C; S2: Prepare a 70mM Tris-HCl solution and adjust the pH to 9 to obtain a Tris-HCl buffer solution; immerse wool fibers with a diameter of 20.5μm and a length of 50mm in the Tris-HCl buffer solution to obtain reaction solution B, wherein the mass-to-volume ratio of wool fibers to Tris-HCl buffer solution is 1g:30mL; add tea polyphenols to obtain reaction solution C, wherein the concentration of tea polyphenols in reaction solution C is 1g / L; stir at 50rpm for 12h, filter, wash, and dry to obtain modified wool fibers; S3: Sodium alginate was added to deionized water and stirred for 4 hours, then allowed to stand for 16 hours to obtain a sodium alginate solution with a mass fraction of 8 wt.%; chitosan was added to a 2% acetic acid aqueous solution and stirred for 3 hours, then allowed to stand to obtain a chitosan solution with a mass fraction of 4 wt.%; the chitosan solution was added to the sodium alginate solution and mixed evenly, then vacuum degassed to obtain a mixed spinning solution, wherein the mass ratio of sodium alginate to chitosan in the mixed spinning solution was 90:10; the mixed spinning solution was loaded into an injection pump and injected at a constant rate of 0.5 mL / m. The fine stream obtained by injection is coagulated to obtain nascent fibers. The spinneret of the injection pump has an orifice diameter of 150 μm. The coagulation solution is an ethanol-water solution of calcium chloride with a mass fraction of 5 wt.% and a volume ratio of ethanol to water of 50:50. After the nascent fibers are first drawn in the coagulation solution, they are second drawn in water at 60°C to obtain pretreated composite filaments. The first drawing ratio is 1.5 times and the second drawing ratio is 2 times. After washing, oiling, and drying, alginate / chitosan composite filaments are obtained. S4: Modified hemp fiber and modified wool fiber are mixed at a mass ratio of 6:4, opened, combed and drawn to obtain fiber slivers, and the fiber slivers and alginate / chitosan composite filaments are spun using a ring spinning device to obtain odor-resistant bio-based wool blended yarn; wherein the alginate / chitosan composite filaments are the core yarn, accounting for 15% of the weight of the yarn.

[0056] Example 3 This embodiment provides an odor-resistant bio-based wool blend yarn and its preparation method. The preparation method of the odor-resistant bio-based wool blend yarn specifically includes the following steps: S1: Soak hemp fibers with a length of 35 mm and a fineness of 8 dtex in deionized water at 65°C for 0.6 h, and dry them to obtain pretreated hemp fibers; add them to the ionic liquid [Bmim]Cl and stir at 95°C and 120 rpm for 5 min to obtain reaction solution A, wherein the mass ratio of pretreated hemp fibers to ionic liquid is 1:40. Mix reaction solution A with deionized water at a volume ratio of 1:7 and stir, filter, wash and dry to obtain modified hemp fibers, wherein the washing is done by alternating between hot water and cold water at 62°C; S2: Prepare a 40mM Tris-HCl solution and adjust the pH to 8.2 to obtain a Tris-HCl buffer solution; immerse wool fibers with a diameter of 19.5μm and a length of 65mm in the Tris-HCl buffer solution to obtain reaction solution B, wherein the mass-to-volume ratio of wool fibers to Tris-HCl buffer solution is 1g:35mL; add tea polyphenols to obtain reaction solution C, wherein the concentration of tea polyphenols in reaction solution C is 2.5g / L; stir at 90rpm for 9h, filter, wash, and dry to obtain modified wool fibers; S3: Sodium alginate was added to deionized water, stirred for 2.5 hours, and then allowed to stand for 19 hours to obtain a sodium alginate solution with a mass fraction of 5 wt.%. Chitosan was added to a 1.8% acetic acid aqueous solution, stirred for 4 hours, and then allowed to stand to obtain a chitosan solution with a mass fraction of 2.5 wt.%. The chitosan solution was added to the sodium alginate solution, mixed evenly, and vacuum degassed to obtain a mixed spinning solution. The mass ratio of sodium alginate to chitosan in the mixed spinning solution was 82:18. The mixed spinning solution was loaded into an injection pump and injected at a constant rate of 0.2 mL. The fine stream obtained by injection at a rate of / min is coagulated to obtain nascent fibers. The spinneret of the injection pump has an orifice diameter of 120μm. The coagulation solution is an ethanol-water solution with a mass fraction of 4wt.% calcium chloride and a volume ratio of ethanol to water of 35:65. After the nascent fibers are first drawn in the coagulation solution, they are second drawn in water at 75℃ to obtain pretreated composite filaments. The first drawing ratio is 1.2 times and the second drawing ratio is 3.5 times. After washing, oiling, and drying, alginate / chitosan composite filaments are obtained. S4: Modified hemp fiber and modified wool fiber are mixed at a mass ratio of 4.5:5.5, opened, combed and drawn to obtain fiber slivers, and the fiber slivers and alginate / chitosan composite filaments are spun using a ring spinning device to obtain odor-resistant bio-based wool blended yarn; wherein the alginate / chitosan composite filaments are the core yarn, accounting for 12% of the weight of the yarn.

[0057] Example 4 This embodiment provides an odor-resistant bio-based wool blend yarn and its preparation method. The preparation method of the odor-resistant bio-based wool blend yarn specifically includes the following steps: S1: Soak hemp fibers with a length of 30 mm and a fineness of 15 dtex in deionized water at 80°C for 0.5 h, and dry them to obtain pretreated hemp fibers; add them to the ionic liquid [Bmim]Cl and stir at 110°C and 100 rpm for 8 min to obtain reaction solution A, wherein the mass ratio of pretreated hemp fibers to ionic liquid is 1:20. Mix reaction solution A with deionized water at a volume ratio of 1:10 and stir, filter, wash and dry to obtain modified hemp fibers, wherein the washing is done by alternating between hot water and cold water at 60°C; S2: Prepare a 30mM Tris-HCl solution and adjust the pH to 8 to obtain a Tris-HCl buffer solution; immerse wool fibers with a diameter of 18.5μm and a length of 70mm in the Tris-HCl buffer solution to obtain reaction solution B, wherein the mass-to-volume ratio of wool fibers to Tris-HCl buffer solution is 1g:50mL; add tea polyphenols to obtain reaction solution C, wherein the concentration of tea polyphenols in reaction solution C is 4g / L; stir at 100rpm for 8h, filter, wash, and dry to obtain modified wool fibers; S3: Sodium alginate was added to deionized water, stirred for 2 hours, and then allowed to stand for 20 hours to obtain a sodium alginate solution with a mass fraction of 4 wt.%. Chitosan was added to a 1% acetic acid aqueous solution, stirred for 6 hours, and then allowed to stand to obtain a chitosan solution with a mass fraction of 2 wt.%. The chitosan solution was added to the sodium alginate solution, mixed evenly, and vacuum degassed to obtain a mixed spinning solution. The mass ratio of sodium alginate to chitosan in the mixed spinning solution was 80:20. The mixed spinning solution was loaded into an injection pump and injected at a constant rate of 0.1 mL / min. The fine stream obtained by the injection pump is coagulated to obtain nascent fibers. The spinneret of the injection pump has an orifice diameter of 80 μm. The coagulation solution is an aqueous solution of calcium chloride in ethanol with a mass fraction of 2 wt.% and a volume ratio of ethanol to water of 30:70. After the nascent fibers are first drawn in the coagulation solution, they are second drawn in water at 80°C to obtain pretreated composite filaments. The first drawing ratio is 1.1 times and the second drawing ratio is 4 times. After washing, oiling, and drying, alginate / chitosan composite filaments are obtained. S4: Modified hemp fiber and modified wool fiber are mixed at a mass ratio of 4:6, opened, combed and drawn to obtain fiber slivers, and the fiber slivers and alginate / chitosan composite filaments are spun using a ring spinning device to obtain odor-resistant bio-based wool blended yarn; wherein the alginate / chitosan composite filaments are the core yarn, accounting for 8% of the weight of the yarn.

[0058] Comparative Example 1 This comparative example provides an odor-resistant bio-based wool blended yarn and its preparation method. The difference from Example 1 is that in S1, a 10-20% sodium hydroxide solution is used to replace the ionic liquid [Bmim]Cl to treat the hemp fiber. Other operating steps and process parameters are exactly the same as in Example 1.

[0059] Comparative Example 2 This comparative example provides an odor-resistant bio-based wool blended yarn and its preparation method. The difference from Example 1 is that in S4, unmodified hemp fiber is used directly, while other operation steps and process parameters are exactly the same as in Example 1.

[0060] Comparative Example 3 This comparative example provides an odor-resistant bio-based wool blended yarn and its preparation method. The difference from Example 1 is that in S2, a nano-silver antibacterial finishing agent is used to modify the surface of the wool fibers. Other operation steps and process parameters are exactly the same as in Example 1.

[0061] Comparative Example 4 This comparative example provides an odor-resistant bio-based wool blended yarn and its preparation method. The difference from Example 1 is that in S4, unmodified wool fibers are used directly, while other operation steps and process parameters are exactly the same as in Example 1.

[0062] The performance of the odor-resistant bio-based wool blended yarns of Examples 1-4 and Comparative Examples 1-4 was tested, and the specific process is as follows: According to GB / T 3916-2013, the single yarn breaking strength and single yarn breaking strength coefficient of the test sample were measured. The coefficient of variation of the uniformity of the strips of the test sample is determined according to GB / T 3292.1-2008. The odor-proof and antibacterial properties of the samples were tested according to GB / T 20944.3-2008.

[0063] The test results are shown in Table 1.

[0064] Table 1. Performance test results of odor-resistant bio-based wool blended yarns from Examples 1-4 and Comparative Examples 1-4

[0065] The test results from Example 1 and Comparative Example 1 show that when sodium hydroxide solution is used instead of ionic liquid to modify hemp fibers, this drastic chemical abrasion process not only removes pectin and lignin but also severely degrades cellulose, damaging the natural high strength of the hemp fibers. Damaged fibers are more prone to breakage during spinning, forming weak loops and thus reducing the overall strength of the final yarn. While strong alkali treatment can remove some of the gum, its effect is not uniform or controllable. Some fiber bundles may be overtreated and become brittle, while others may be undertreated and remain stiff. This inhomogeneity leads to extreme instability in fiber performance during drafting, forming numerous thick and thin knots, thus increasing the coefficient of variation of yarn breaking strength and evenness. The final antibacterial properties of the yarn are mainly determined by the tea polyphenol-modified wool and core yarn. The modification methods for hemp fibers primarily affect physical properties and comfort, with little impact on the final yarn's odor-resistant and antibacterial properties.

[0066] The test results from Example 1 and Comparative Example 2 show that while unmodified hemp fibers have high single-fiber strength, their stiffness and poor cohesion in yarn prevent effective load transfer between fibers. The yarn is more prone to breakage due to fiber slippage, resulting in decreased breaking strength. Unmodified raw hemp fiber bundles are extremely difficult to separate and control effectively during carding and drafting, interfering with normal fiber movement and causing severe unevenness in yarn thickness. This leads to highly unstable yarn strength, meaning increased coefficients of variation for breaking strength and evenness. Similarly, the impact on deodorizing and antibacterial properties is relatively small.

[0067] The test results from Example 1 and Comparative Example 3 show that nano-silver finishing is a surface deposition technology with minimal impact on the physical properties of wool fibers. Freshly prepared nano-silver particles possess extremely high specific surface area and bioactivity, exhibiting very high initial bactericidal efficiency. However, the binding of nano-silver particles to wool fibers is primarily due to physical adsorption and van der Waals forces, resulting in relatively weak binding. Under repeated mechanical rubbing and the action of chemical detergents, the nano-silver particles gradually detach and are lost, leading to a decrease in their antibacterial properties with increasing washing cycles.

[0068] The test results from Example 1 and Comparative Example 4 show that tea polyphenol modification is a nanoscale surface treatment that has little impact on the physical properties of wool. Therefore, using raw wool, the physical properties of the yarn do not change significantly; however, lacking the broad-spectrum antibacterial and antioxidant (flavor suppression from the source) effects of tea polyphenols, the initial antibacterial performance is weakened, and the long-lasting antibacterial effect almost entirely depends on the core yarn. Without the protection of tea polyphenols, the antibacterial rate decreases after 100 washes.

[0069] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing an odor-resistant bio-based wool blended yarn, characterized in that, The preparation method includes: S1: Soak hemp fibers in deionized water and dry them to obtain pretreated hemp fibers; add them to the ionic liquid [Bmim]Cl and stir to obtain reaction solution A; mix reaction solution A with deionized water and stir, filter, wash and dry to obtain modified hemp fibers; S2: Prepare a Tris-HCl solution and adjust the pH value to obtain a Tris-HCl buffer solution; soak wool fibers in the Tris-HCl buffer solution to obtain reaction solution B, add tea polyphenols to obtain reaction solution C, stir the reaction, filter, wash and dry to obtain modified wool fibers. S3: Sodium alginate is added to deionized water, stirred, and allowed to stand to obtain a sodium alginate solution; chitosan is added to an aqueous acetic acid solution, stirred, and allowed to stand to obtain a chitosan solution; the chitosan solution is added to the sodium alginate solution, mixed evenly, and vacuum degassed to obtain a mixed spinning solution; the mixed spinning solution is loaded into an injection pump, and the resulting fine stream is injected through a coagulation solution to obtain nascent fibers; the nascent fibers undergo a first stretching in the coagulation solution and a second stretching in water to obtain pretreated composite filaments; subsequently, after washing, oiling, and drying, alginate / chitosan composite filaments are obtained. S4: Mix modified hemp fiber and modified wool fiber, open, comb, and draw to obtain fiber sliver, and use a ring spinning device to spin the fiber sliver and alginate / chitosan composite filament to obtain odor-resistant bio-based wool blended yarn.

2. The method for preparing an odor-resistant bio-based wool blended yarn according to claim 1, characterized in that, In S1: the mass ratio of the pretreated hemp fiber to the ionic liquid is 1:(20-50).

3. The method for preparing an odor-resistant bio-based wool blended yarn according to claim 1, characterized in that, In S1: The temperature at which the pretreated hemp fibers are added to the ionic liquid [Bmim]Cl and stirred is 90-110℃. The pretreated hemp fibers were added to the ionic liquid [Bmim]Cl and stirred at a speed of 100-200 rpm. The pretreated hemp fibers were added to the ionic liquid [Bmim]Cl and stirred for 3-8 minutes.

4. The method for preparing an odor-resistant bio-based wool blended yarn according to claim 1, characterized in that, In S1: The washing process involves alternating between hot and cold water.

5. The method for preparing an odor-resistant bio-based wool blended yarn according to claim 1, characterized in that, In S2: the mass-to-volume ratio of the wool fiber to the Tris-HCl buffer solution is 1 g:(30-50) mL.

6. The method for preparing an odor-resistant bio-based wool blended yarn according to claim 1, characterized in that, In S2: the concentration of the tea polyphenols in reaction solution C is 1-4 g / L.

7. The method for preparing an odor-resistant bio-based wool blended yarn according to claim 1, characterized in that, In S3: The mass ratio of sodium alginate to chitosan in the mixed spinning solution is (80-90):(20-10).

8. The method for preparing an odor-resistant bio-based wool blended yarn according to claim 1, characterized in that, In S3: The coagulation solution is an ethanol-water solution of calcium chloride, with a mass fraction of 2-5 wt.%. The volume ratio of ethanol to water in the coagulated liquid is (30-50):(70-50).

9. The method for preparing an odor-resistant bio-based wool blended yarn according to claim 1, characterized in that, In S4: The mass ratio of the modified hemp fiber to the modified wool fiber is (4-6):(6-4); The alginate / chitosan composite filament is the core yarn; The alginate / chitosan composite filament accounts for 8-15% of the weight of the odor-resistant bio-based wool blended yarn.

10. An odor-resistant bio-based wool blended yarn prepared by the preparation method according to any one of claims 1-9.

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