Antibacterial composite fabric and preparation method thereof

Abstract

The invention relates to the technical field of textile fabrics, in particular to an antibacterial composite fabric and a preparation method thereof. The antibacterial composite fabric is formed by blending and weaving reinforced fibers and photoresponse antibacterial fibers, and the photoresponse antibacterial fibers comprise the following components: regenerated polyester, propyl gallate, nano-zinc oxide, trimellitic anhydride and a catalyst; the reinforced fiber comprises the following components: regenerated polyester, nano cellulose with amino introduced on the surface through siloxane modification, and an ecological antibacterial agent. Trimellitic anhydride is introduced to be copolymerized with regenerated polyester, so that the hygroscopicity of the fiber is improved, and carboxyl is introduced; the antibacterial components propyl gallate and nano-zinc oxide realize double antibacterial effects of illumination triggering and contact sterilization through an organic-inorganic synergistic mechanism. The mechanical strength of the fiber is improved through the rigid structure of the aminated cellulose nanocrystals in the reinforced fiber; finally, chemical bridging is formed on a fiber interface through a thermal process, and the fabric with strength and lasting antibacterial property is created.

Description

Technical Field

[0001] This application relates to the field of textile fabric technology, and in particular to an antibacterial composite fabric and its preparation method. Background Technology

[0002] The textile industry is increasingly focusing on the combination of functionality and environmental protection, with antibacterial composite fabrics becoming a research hotspot due to their wide application in medical protective equipment, sportswear, and home textiles. These fabrics are typically prepared by combining recycled environmentally friendly fibers with various antibacterial agents through blending, coating, or finishing processes. The aim is to endow the materials with long-lasting antibacterial and bactericidal capabilities while meeting the requirements of sustainable development.

[0003] However, existing antibacterial composite fabrics still have significant drawbacks. First, the functional components and matrix fibers are mostly bonded physically, resulting in weak interfacial interactions. This leads to a sharp decline in antibacterial properties and insufficient durability after repeated washing or friction. Second, the introduction of antibacterial agents often negatively impacts the mechanical properties of the fibers themselves, causing problems such as decreased strength and increased brittleness, thus affecting the fabric's durability. Furthermore, simply stacking different functions fails to achieve synergistic effects and may instead lead to functional conflicts or instability in the material system.

[0004] Therefore, existing technologies urgently need to break through the limitations of traditional physical mixing and develop a high-performance composite fabric that can simultaneously achieve long-lasting antibacterial properties and enhanced mechanical strength through innovative material combinations and structural designs. Summary of the Invention

[0005] This application provides an antibacterial composite fabric and its preparation method, which combines long-lasting antibacterial properties with enhanced mechanical strength.

[0006] An antibacterial composite fabric is made of a blend of reinforcing fibers and photoresponsive antibacterial fibers, wherein the reinforcing fibers account for 60%-80% by mass and the photoresponsive antibacterial fibers account for 20%-40% by mass. The photoresponsive antibacterial fiber comprises the following components by weight percentage: 88-94% recycled polyester, 3-6% propyl gallate, 1-3% nano zinc oxide, 0.5-2% trimellitic anhydride, and 0.5-2% catalyst. The reinforcing fiber comprises, by weight percentage, the following components: 88-96% recycled polyester, 2-8% nanocellulose with amino groups introduced into the surface through siloxane modification, and 1-5% eco-friendly antibacterial agent.

[0007] By adopting the above technical solution, the photoresponsive synergistic antibacterial fiber uses recycled polyester as the matrix to construct an antibacterial synergistic system. Propyl gallate, as an organic antibacterial agent, achieves rapid contact sterilization by disrupting the cell membrane structure of microorganisms and inhibiting their metabolic processes. Simultaneously, its abundant phenolic hydroxyl groups endow the fiber with enhanced antioxidant properties, effectively preventing the aging and yellowing of the polymer matrix. Nano-zinc oxide, as an inorganic antibacterial component, catalyzes the generation of reactive oxygen species under light conditions to oxidize and eliminate microorganisms, and provides a highly efficient physical UV shielding function. Specifically, propyl gallate provides immediate contact sterilization, while nano-zinc oxide provides reactive oxygen species generation under light to assist in sterilization. At the same time, the UV protection function of nano-zinc oxide protects propyl gallate from photodecomposition, and the antioxidant function of propyl gallate protects the fiber structure, together achieving a highly efficient and long-lasting antibacterial function.

[0008] Trimeric triphthalic anhydride, a comonomer, was introduced into photocatalytic antibacterial fibers. During the fiber processing, the anhydride groups of trimellitic anhydride underwent a ring-opening esterification reaction with the hydroxyl groups at the ends of the polyester molecular chains, successfully introducing carboxyl groups into the polymer backbone via covalent bonds. The introduced carboxyl groups then formed strong hydrogen bonds (OH...O=C) with the phenolic hydroxyl groups in propyl gallate molecules. These strong hydrogen bonds anchored propyl gallate molecules more firmly within the polymer matrix, effectively inhibiting the migration and precipitation of propyl gallate during processing or subsequent washing, thus improving the durability of the antibacterial function. Simultaneously, the highly polar carboxyl groups of trimellitic anhydride effectively improved the fiber's hydrophilicity and hygroscopicity, and provided more binding sites for dye molecules, enhancing the dye uptake and color fastness in subsequent dyeing. After melt copolymerization, spinning, and drawing, a multifunctional antibacterial fiber with a surface rich in carboxyl reaction sites was finally obtained.

[0009] Secondly, the reinforcing fiber uses recycled polyester as the matrix and selects aminated nanocellulose as the fiber reinforcing phase. The surface of the nanocellulose is modified with siloxanes to introduce amino groups and improve its compatibility. Furthermore, nanocellulose itself has high specific strength and modulus; its rigid structure plays a reinforcing and toughening role in the polyester matrix, effectively transferring and dispersing stress, thus improving the physical properties of the fiber. Based on this, an eco-friendly antibacterial agent is introduced as an antibacterial aid for the photoresponsive antibacterial fiber. The fiber is then produced using melt blending spinning technology, resulting in a reinforcing fiber that combines mechanical properties with antibacterial function and has a surface rich in amino reaction sites.

[0010] Subsequently, the two fibers are blended in a predetermined ratio, achieving only a physical bond between them. During the heat setting stage of the finishing process, the carboxyl groups on the surface of the photoresponsive antibacterial fiber undergo an amidation condensation reaction with the amino groups on the surface of the reinforcing fiber, removing one molecule of water and forming a strong covalent amide bond (-CO-NH-). The strength of this covalent bond exceeds van der Waals forces, improving the fabric's tear strength, bursting strength, and abrasion resistance, thus enhancing its mechanical properties. Secondly, the cross-linked covalent bonds restrict molecular chain slippage, improving the fabric's stability and wrinkle resistance. Furthermore, both amino and carboxyl groups are hydrophilic, guiding moisture and increasing the fabric's hygroscopicity, accelerating the response efficiency of the antibacterial function. Ultimately, by elevating textile material composite technology from physical mixing to chemical interconnection, a fabric with enhanced mechanical strength, antibacterial properties, comfort, and durability is obtained.

[0011] Optionally, the nanocellulose is cellulose nanocrystals.

[0012] By employing the above-mentioned technical solution, cellulose nanocrystals are rigid rod-shaped nanoparticles with high crystallinity. Their high specific modulus makes them ideal stress-bearing materials, capable of efficiently transferring and dispersing external forces through the interface, thereby enhancing fiber strength. Furthermore, their excellent thermal stability ensures structural integrity during polyester melt processing, preventing thermal degradation. Simultaneously, the abundant hydroxyl groups on the surface of cellulose nanocrystals provide a platform for chemical modification. After amination, they not only retain their reinforcing properties but also become functional units carrying reaction sites. The amino groups on their surface provide the molecular basis for subsequent interfacial amidation covalent bonding with antibacterial fibers, thus achieving a leap from mechanical reinforcement to chemical synergy.

[0013] Optionally, the catalyst is an antimony-based catalyst, including one or more of antimony trioxide and antimony acetate.

[0014] By adopting the above technical solution, the antimony-based catalyst, through the introduction of its dissociated antimony ions, acts as a highly efficient electron pair acceptor, which can precisely coordinate carbonyl oxygen atoms, enhance the positive charge of carbonyl carbon, thereby reducing the reaction energy barrier and efficiently catalyzing the ring-opening esterification reaction of trimellitic anhydride and polyester.

[0015] Optionally, the recycled polyester is a recycled PET material made from waste PET bottles.

[0016] By adopting the above technical solution, the recycled polyester molecular chains made from waste PET bottles retain abundant active reaction sites such as terminal hydroxyl and terminal carboxyl groups. This ensures that it can smoothly undergo ring-opening esterification and other chemical reactions during melt blending with trimellitic anhydride and cellulose nanocrystals, thus providing an ideal platform for the effective integration and uniform dispersion of functional molecules. Simultaneously, PET material possesses excellent mechanical properties and thermal stability, providing reliable basic strength and spinnability for the fibers. Transforming post-consumer waste into high-value-added products reduces dependence on resources and environmental pollution, achieving a unity between the circular economy concept and product performance.

[0017] Optionally, the eco-friendly antibacterial agent is one or more of bamboo charcoal particles and chitin.

[0018] By employing the above technical solutions, bamboo charcoal granules, with their rich and porous microstructure, physically adsorb and capture microorganisms through their large specific surface area, while simultaneously and efficiently adsorbing and decomposing odor molecules, achieving long-lasting deodorization. Chitosan, a natural biological polysaccharide, has positively charged groups on its derivative chitosan molecular chains that can specifically adsorb negatively charged bacterial cell membranes, causing cell death by disrupting cell membrane permeability and leading to the outflow of intracellular substances. The eco-friendly antibacterial agent and the photoresponsive antibacterial fiber complement each other, synergistically enhancing the fabric's antibacterial efficiency.

[0019] Optionally, the method for preparing the photoresponsive antibacterial fiber includes the following steps: S1. Premix the recycled polyester, propyl gallate, nano zinc oxide, trimellitic anhydride and catalyst. S2. The mixture from step S1 is fed into a twin-screw extruder and subjected to melt reaction co-extrusion at 255-285℃ for a reaction residence time of 15-45 minutes. The mixture is then granulated to obtain antibacterial masterbatch. S3. The antibacterial masterbatch is melt-spun and drawn to obtain photoresponsive antibacterial fibers with a surface rich in carboxyl groups.

[0020] By employing the above-mentioned technical solution, the preparation of photoresponsive antibacterial fibers involves a simple process that involves ring-opening esterification of trimellitic anhydride with recycled polyester, introducing carboxyl groups into the molecular chain. This not only provides sites for subsequent interfacial bonding but also improves the fiber's hydrophilicity and dyeability. The carboxyl groups of trimellitic anhydride form hydrogen bonds with the phenolic hydroxyl groups of propargyl gallate, effectively anchoring the antibacterial molecules and enhancing antibacterial durability, ultimately yielding a multifunctional durable fiber that combines antibacterial and hydrophilic properties.

[0021] Optionally, the method for preparing the reinforcing fiber includes the following steps: S1. Aminated nanocellulose was obtained by surface modification of nanocellulose with 3-aminopropyltriethoxysilane. S2. Premix recycled polyester, aminated nanocellulose and eco-friendly antibacterial agent; S3. The mixture from step S2 is fed into a twin-screw extruder and melt-blended at 255-280℃, then granulated to obtain reinforced masterbatch. S4. The reinforcing masterbatch is melt-spun and drawn to obtain reinforcing fibers with amino-rich surfaces.

[0022] By employing the above-mentioned technical solution, highly active amino functional groups are introduced into nanocellulose through siloxane modification, enhancing its interfacial compatibility and bonding strength with the recycled polyester matrix. This process utilizes twin-screw melt blending to achieve uniform dispersion of the aminated nanocellulose and the eco-friendly antibacterial agent, ultimately resulting in fibers that integrate mechanical reinforcement, eco-friendly antibacterial properties, and surface reactivity.

[0023] Optionally, a method for preparing an antibacterial composite fabric includes the following steps: S1. Spinning Process: The reinforcing fibers and light-responsive antibacterial fibers are opened and combed separately, then mixed according to a set mass ratio, and processed into composite yarn through drawing, roving, and spinning processes. During the spinning process, the spinning speed is controlled at 100-150 m / min. S2. Weaving process: The composite yarn is woven into greige fabric using an air-jet loom or rapier loom. During the weaving process, the weaving speed is controlled at 200-300 r / min, the warp tension is 200-300 N, and the weft tension is 150-250 N. S3. Finishing Processes: The woven fabric undergoes desizing, bleaching, dyeing, and setting processes. Desizing uses a bio-enzyme desizing process; bleaching uses hydrogen peroxide; dyeing uses reactive dyes; during setting, the setting temperature is controlled at 120-150℃, and the setting time is 30-60 seconds.

[0024] By adopting the above technical solutions and a series of precisely controlled process parameters, high-performance antibacterial composite fabrics were produced efficiently and environmentally. In the spinning process, controlling the spinning speed to 100-150 m / min ensured the uniform mixing and stable yarn formation of the reinforcing fibers and the photoresponsive antibacterial fibers, laying a strong foundation for the fabric's resilience. The weaving process employed a weaving speed of 200-300 r / min, coupled with warp tension of 200-300 N and weft tension of 150-250 N, effectively avoiding problems such as yarn breakage and skipped yarns, ensuring a smooth and tightly woven high-quality fabric structure. In the finishing process, the bio-enzyme desizing and hydrogen peroxide bleaching processes significantly reduced environmental pollution; while the setting conditions of 120-150℃ and 30-60 seconds perfectly achieved fabric dimensional stability and setting, while also providing optimal conditions for triggering key reactions at the fiber interface, improving the fabric's functional durability. The entire process flowed smoothly and collaboratively, not only ensuring high production efficiency and environmental protection but also directly giving the fabric durable antibacterial and high-strength properties.

[0025] In summary, this application includes at least one of the following beneficial technical effects: 1. By introducing aminated nanocellulose and eco-friendly antibacterial agents, the mechanical properties and antibacterial functions are improved. Aminated nanocellulose, with its rigid structure, acts as a stress transfer point, enhancing the strength of the fiber; its surface amino groups provide active sites for subsequent interfacial reactions. Simultaneously, the eco-friendly antibacterial agent endows the fiber with reliable antibacterial capabilities, providing an auxiliary antibacterial barrier for the fabric. 2. The carboxyl groups introduced by the copolymerization of recycled polyester and trimellitic anhydride provide reaction sites for covalent bonding between fibers, and further stabilize and anchor propyl gallate molecules through hydrogen bonding, effectively inhibiting their migration and precipitation, and improving the antibacterial durability of propyl gallate; at the same time, it forms a synergistic and complementary antibacterial effect with the photocatalyst nano zinc oxide, the propyl gallate molecules quickly contact and kill bacteria, and the nano zinc oxide generates active oxygen under light to permanently eliminate microorganisms, thus achieving the antibacterial effect; 3. During the fabric preparation process, the carboxyl groups of the photoresponsive antibacterial fiber and the amino groups of the reinforcing fiber form covalent amide bonds, firmly binding the two fibers and improving the fabric's tear strength and abrasion resistance. Simultaneously, the hydrophilic groups at the interface possess excellent hygroscopic properties, accelerating the antibacterial response and resulting in a fabric with enhanced mechanical strength, antibacterial properties, and durability. Detailed Implementation

[0026] Example 1 An antibacterial composite fabric is made of a blend of reinforcing fibers and photoresponsive antibacterial fibers, wherein the reinforcing fibers account for 60% by mass and the photoresponsive antibacterial fibers account for 40% by mass. The photoresponsive antibacterial fiber comprises the following components by weight percentage: 91% recycled polyester, 4% propyl gallate, 2% nano zinc oxide, 2% trimellitic anhydride, and 1% catalyst. The reinforcing fiber comprises the following components by weight percentage: 92% recycled polyester, 5% nanocellulose with amino groups introduced through siloxane treatment, and 3% eco-friendly antimicrobial agent.

[0027] Specifically, the catalyst is antimony trioxide; the nanocellulose is cellulose nanocrystals; the eco-friendly antibacterial agent is a mixture of bamboo charcoal particles and chitin in a 1:1 mass ratio; and the recycled polyester is recycled PET material made from waste PET bottles.

[0028] The preparation method of photoresponsive antibacterial fibers includes the following steps: S1. Premix the recycled polyester, propyl gallate, nano zinc oxide, trimellitic anhydride and catalyst. S2. The mixture from step S1 is fed into a twin-screw extruder and co-extruded at 275°C for a reaction time of 30 minutes. The mixture is then granulated to obtain antibacterial masterbatch. S3. The antibacterial masterbatch is melt-spun and drawn to obtain photoresponsive antibacterial fibers with a surface rich in carboxyl groups.

[0029] The method for preparing reinforcing fibers includes the following steps: S1. Aminated nanocellulose was obtained by surface modification of nanocellulose with 3-aminopropyltriethoxysilane. S2. Premix recycled polyester, aminated nanocellulose and eco-friendly antibacterial agent; S3. The mixture from step S2 is fed into a twin-screw extruder, melt-blended at 260°C, and granulated to obtain reinforced masterbatch. S4. The reinforcing masterbatch is melt-spun and drawn to obtain reinforcing fibers with amino-rich surfaces.

[0030] A method for preparing an antibacterial composite fabric includes the following steps: S1. Spinning Process: The reinforcing fiber and the light-responsive antibacterial fiber are opened and combed separately, then mixed according to a set mass ratio, and processed into composite yarn through drawing, roving, and spinning processes. During the spinning process, the spinning speed is controlled at 120m / min. S2. Weaving Process: The composite yarn is woven into a grey fabric using an air-jet loom or rapier loom. During the weaving process, the weaving speed is controlled at 250 r / min, the warp tension is 250 N, and the weft tension is 200 N. S3. Finishing Process: The woven fabric undergoes desizing, bleaching, dyeing, and setting processes. Desizing is performed using a bio-enzyme desizing process; bleaching is done using hydrogen peroxide; dyeing is done using reactive dyes; during setting, the setting temperature is controlled at 130℃ and the setting time is 50 seconds to obtain an antibacterial composite fabric.

[0031] Example 2 An antibacterial composite fabric differs from Example 1 in that the reinforcing fiber accounts for 70% of the mass and the photoresponsive antibacterial fiber accounts for 30% of the mass.

[0032] Example 3 An antibacterial composite fabric differs from Example 1 in that the reinforcing fiber accounts for 80% of the mass and the photoresponsive antibacterial fiber accounts for 20% of the mass.

[0033] Example 4 An antibacterial composite fabric, which differs from Example 2 in that the photoresponsive antibacterial fiber comprises the following components: 88% recycled polyester, 6% propyl gallate, 3% nano zinc oxide, 2% trimellitic anhydride, and 1% catalyst.

[0034] Example 5 An antibacterial composite fabric, which differs from Example 2 in that the photoresponsive antibacterial fiber comprises the following components: 94% recycled polyester, 3% propyl gallate, 1% nano zinc oxide, 1.5% trimellitic anhydride, and 0.5% catalyst.

[0035] Example 6 An antibacterial composite fabric, which differs from Example 2 in that the reinforcing fiber comprises the following components: 88% recycled polyester, 8% nanocellulose with amino groups introduced by siloxane treatment, and 4% eco-friendly antibacterial agent.

[0036] Example 7 An antibacterial composite fabric, which differs from Example 2 in that the reinforcing fiber comprises the following components: 96% recycled polyester, 6% nanocellulose with amino groups introduced through siloxane treatment, and 6% eco-friendly antibacterial agent.

[0037] Example 8 An antibacterial composite fabric differs from Example 6 in that the nanocellulose in the reinforcing fiber is replaced with an equal amount of cellulose nanocrystals that have not been modified with siloxanes to introduce amino groups.

[0038] Example 9 An antibacterial composite fabric differs from Example 6 in that nano zinc oxide is replaced with an equal amount of propyl gallate.

[0039] Example 10 An antibacterial composite fabric differs from Example 6 in that propyl gallate is replaced with an equal amount of nano zinc oxide.

[0040] Comparative Example 1 An antibacterial composite fabric differs from Example 1 in that the nanocellulose in the reinforcing fiber is replaced with an equal amount of cellulose nanofibers with amino groups introduced by siloxane treatment.

[0041] Comparative Example 2 An antibacterial composite fabric differs from Example 1 in that trimellitic anhydride is replaced with an equal amount of sodium isophthalic acid-5-sulfonate.

[0042] Detection example Antibacterial test: The antibacterial properties of the fabric were tested according to AATCC-100-2012; Water absorption test: The water absorption of the fiber fabric was tested according to GB / T 21665.1-2008; The test results are shown in Table 1.

[0043] Table 1 Testing items Water droplet diffusion time (s) Antibacterial rate (%) Spinability Example 1 0.71 99.13 No broken fibers, smooth fiber surface Example 2 0.67 99.61 No broken fibers, smooth fiber surface Example 3 0.69 98.42 No broken fibers, smooth fiber surface Example 4 0.78 98.13 No broken fibers, smooth fiber surface Example 5 0.75 97.89 No broken fibers, smooth fiber surface Example 6 0.86 97.45 No broken fibers, smooth fiber surface Example 7 0.82 97.68 No broken fibers, smooth fiber surface Example 8 1.17 94.08 Broken thread Example 9 0.98 88.56 No broken fibers, smooth fiber surface Example 10 1.04 79.64 No broken fibers, smooth fiber surface Comparative Example 1 0.93 95.52 No broken wires, rough surface Comparative Example 2 1.21 93.86 Broken thread As shown in the performance test data tables of Examples 1-10 and Comparative Examples 1-2, by introducing trimellitic anhydride and recycled polyester copolymerization, abundant carboxyl groups are formed on the surface of the antibacterial fiber. These carboxyl groups not only provide active sites for subsequent crosslinking but also enhance the hydrophilicity of the fiber and improve the moisture absorption of the fabric. The antibacterial component propyl gallate and nano zinc oxide achieve a dual antibacterial effect of light-triggered and contact sterilization through an organic-inorganic synergistic mechanism. The aminated cellulose nanocrystals in the reinforcing fiber effectively improve the mechanical strength of the fiber with their nanoscale rigid structure. Finally, the amidation reaction of carboxyl and amino groups is triggered by the heat setting process, forming covalent bonds at the fiber interface, thereby creating a fiber fabric that combines strength, long-lasting antibacterial properties, and excellent comfort.

[0044] Please note that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An antibacterial composite fabric, characterized in that: It is woven from a blend of reinforcing fibers and photoresponsive antibacterial fibers, wherein the reinforcing fibers account for 60%-80% by mass and the photoresponsive antibacterial fibers account for 20%-40% by mass. The photoresponsive antibacterial fiber comprises the following components by weight percentage: 88-94% recycled polyester, 3-6% propyl gallate, 1-3% nano zinc oxide, 0.5-2% trimellitic anhydride, and 0.5-2% catalyst; The reinforcing fiber comprises the following components by weight percentage: 88-96% recycled polyester, 2-8% nanocellulose with amino groups introduced into the surface by siloxane modification, and 1-5% eco-friendly antibacterial agent.

2. The antibacterial composite fabric according to claim 1, characterized in that: The nanocellulose is cellulose nanocrystals.

3. The antibacterial composite fabric according to claim 1, characterized in that: The catalyst is an antimony-based catalyst, including one or more of antimony trioxide and antimony acetate.

4. The antibacterial composite fabric according to claim 1, characterized in that: The recycled polyester is a recycled PET material made from waste PET bottles.

5. The antibacterial composite fabric according to claim 1, characterized in that: The ecological antibacterial agent is one or more of bamboo charcoal granules and chitin.

6. The antibacterial composite fabric according to claim 1, characterized in that: The method for preparing the photoresponsive antibacterial fiber includes the following steps: S1. Premix the recycled polyester, propyl gallate, nano zinc oxide, trimellitic anhydride and catalyst. S2. The mixture from step S1 is fed into a twin-screw extruder and subjected to melt reaction co-extrusion at 255-285℃ for a reaction residence time of 15-45 minutes. The mixture is then granulated to obtain antibacterial masterbatch. S3. The antibacterial masterbatch is melt-spun and drawn to obtain photoresponsive antibacterial fibers with a surface rich in carboxyl groups.

7. The antibacterial composite fabric according to claim 1, characterized in that: The method for preparing the reinforcing fiber includes the following steps: S1. Aminated nanocellulose was obtained by surface modification of nanocellulose with 3-aminopropyltriethoxysilane. S2. Premix recycled polyester, aminated nanocellulose and eco-friendly antibacterial agent; S3. The mixture from step S2 is fed into a twin-screw extruder and melt-blended at 255-280℃, then granulated to obtain reinforced masterbatch. S4. The reinforcing masterbatch is melt-spun and drawn to obtain reinforcing fibers with amino-rich surfaces.

8. A method for preparing an antibacterial composite fabric according to any one of claims 1-7, characterized in that: Includes the following steps: S1. Spinning Process: The reinforcing fibers and light-responsive antibacterial fibers are opened and combed separately, then mixed according to a set mass ratio, and processed into composite yarn through drawing, roving, and spinning processes. During the spinning process, the spinning speed is controlled at 100-150 m / min. S2. Weaving process: The composite yarn is woven into greige fabric using an air-jet loom or rapier loom. During the weaving process, the weaving speed is controlled at 200-300 r / min, the warp tension is 200-300 N, and the weft tension is 150-250 N. S3. Finishing Processes: The woven fabric undergoes desizing, bleaching, dyeing, and setting processes. Desizing uses a bio-enzyme desizing process; bleaching uses hydrogen peroxide; dyeing uses reactive dyes; during setting, the setting temperature is controlled at 120-150℃, and the setting time is 30-60 seconds.