A composite nonwoven fabric and its manufacturing method

Abstract

This invention relates to the field of nonwoven fabric manufacturing technology, specifically to a composite nonwoven fabric, comprising: a base layer, wherein the base layer is composed of a biomass fiber layer and a synthetic fiber reinforcing layer, and the surface of the biomass fiber layer forms a micro-nano-scale rough structure; an antibacterial functional layer, disposed on the surface of the base layer, composed of biomass nanofibers loaded with antibacterial agents, wherein the biomass nanofibers are obtained by nano-processing cellulose or chitosan; and a protective surface layer, which significantly improves the overall strength of the composite nonwoven fabric by combining the biomass fiber layer with a micro-nano-scale rough surface structure to increase the friction and cohesion between fibers with a high-strength synthetic fiber reinforcing layer formed by a three-dimensional weaving method that evenly distributes the fibers in all directions to form a strong mesh structure. This allows the composite nonwoven fabric to withstand greater tensile and tear forces, making it less prone to damage in various application scenarios and extending its service life.

Description

Technical Field

[0001] This invention relates to the field of nonwoven fabric manufacturing technology, specifically to a composite nonwoven fabric and its manufacturing method. Background Technology

[0002] Non-woven fabric, also known as non-woven cloth, is a type of fabric formed without spinning or weaving. It has advantages such as short production process, high output, low cost, and wide range of uses, and is widely used in many fields such as medical, hygiene, filtration, and packaging. As people pay more and more attention to environmental protection and health, higher requirements are also being placed on the performance of non-woven fabric.

[0003] In existing technologies, traditional nonwoven fabrics have certain limitations in terms of strength, antibacterial properties, and environmental friendliness. On the one hand, to improve the strength of nonwoven fabrics, chemical fibers or chemical auxiliaries are often used, but this often leads to poor biodegradability, which is inconsistent with environmental protection principles. On the other hand, ordinary nonwoven fabrics have poor antibacterial properties, making it difficult to meet the needs of medical and hygiene fields with high hygiene requirements. In addition, some nonwoven fabrics containing antibacterial components are prone to loss of these components during use, resulting in a lack of long-lasting antibacterial effect.

[0004] For example, the meltblown-wood pulp composite nonwoven fabric shown in the existing patent with publication number CN101978107A has certain biodegradability, but it is insufficient in terms of strength and antibacterial properties. In the existing patent with publication number CN116163068A, there is room for improvement in the transition between hydrophilic and hydrophobic layers and the unidirectional hydrophoretic effect, and it does not focus on strength and antibacterial properties. As for the technology of fixing inorganic porous materials such as activated carbon and zeolite or metal-organic structures (MOFs) on nonwoven fabrics, there are problems such as small specific surface area, complex preparation process, easy shedding, and poor air permeability. In view of this, we propose a composite nonwoven fabric and its manufacturing method. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing nonwoven fabrics in terms of strength, antibacterial properties, and environmental friendliness, and to provide a composite nonwoven fabric and its manufacturing method.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A composite nonwoven fabric, comprising:

[0008] The base layer is composed of a biomass fiber layer and a synthetic fiber reinforcement layer, and the surface of the biomass fiber layer forms a micro-nano-scale rough structure.

[0009] An antibacterial functional layer is disposed on the surface of the base layer and is composed of biomass nanofibers loaded with antibacterial agents. The biomass nanofibers are obtained by nano-processing cellulose or chitosan.

[0010] The protective surface layer, covering the surface of the antibacterial functional layer, is composed of a biomass fiber film that has been treated to be waterproof and oil-proof. The biomass fiber film is made of polylactic acid and polyhydroxyalkanoate.

[0011] Preferably, the biomass fiber layer is composed of one or more of wood pulp fiber, bamboo fiber, and hemp fiber.

[0012] Preferably, the synthetic fiber reinforcing layer is composed of aramid fibers and ultra-high molecular weight polyethylene fibers using a three-dimensional weaving method.

[0013] Preferably, the antibacterial agent includes natural antibacterial components and inorganic antibacterial agents. The natural antibacterial components are composed of one or more of tea polyphenols, artemisia argyi extract, and allicin, and the inorganic antibacterial agents are composed of nano-silver particles.

[0014] Preferably, the mass ratio of the natural antibacterial component to the inorganic antibacterial agent in the antibacterial functional layer is (2-5):(1-3).

[0015] Preferably, the antibacterial agent is loaded onto the surface of the biomass nanofibers through physical adsorption and chemical bonding.

[0016] Preferably, the aramid fiber or ultra-high molecular weight polyethylene fiber accounts for 60%-80% of the volume in the synthetic fiber reinforcement layer.

[0017] A method for manufacturing a composite nonwoven fabric includes the following steps:

[0018] Step 1: After screening and washing the wood pulp fiber and bamboo fiber, soak them in a solution containing surfactant and sodium hydroxide for alkaline treatment, then rinse them with water until neutral and dry them to obtain the pretreated biomass fiber layer.

[0019] Step 2: Aramid fibers and ultra-high molecular weight polyethylene fibers are woven in a three-dimensional braiding manner, and an adhesive is added during the weaving process to obtain a synthetic fiber reinforcement layer;

[0020] Step 3: Using a hot-pressing composite process, the pretreated biomass fiber layer and synthetic fiber reinforcement layer are hot-pressed at 150-200℃ and 5-10MPa for 5-10 minutes to obtain the base layer;

[0021] Step 4: Using cellulose as raw material, prepare biomass nanofibers using chemical or physical methods. Soak the prepared biomass nanofibers in a solution of natural antibacterial components and inorganic antibacterial agents for 1-2 hours, then dry them to obtain biomass nanofibers. Then, use spraying or scraping to uniformly coat the biomass nanofibers loaded with antibacterial agents onto the surface of the base layer to form an antibacterial functional layer with a thickness of 5-10 μm.

[0022] Step 5: Polyhydroxyalkanoates are prepared into biomass fiber films by melt extrusion or solution casting, and then cooled and stretched. The biomass fiber films are then immersed in a solution containing waterproof and oil-repellent agents for 30-60 minutes, dried, and then hot-pressed onto the surface of the antibacterial functional layer using a hot-pressing composite process at 100-150℃ and 3-5MPa for 3-5 minutes to obtain composite nonwoven fabric.

[0023] Step Six: Finally, the prepared composite nonwoven fabric is cut, sorted, slit, and packaged.

[0024] Preferably, in step one, the mass fraction of the surfactant treated with alkali is 0.5%-2%, the mass fraction of sodium hydroxide is 2%-5%, the treatment temperature is 50-70℃, and the treatment time is 1-3 hours.

[0025] Preferably, in step five, the waterproof and oil-repellent agent is a fluoropolymer or an organosilicon compound, and its mass fraction in the waterproof and oil-repellent treatment solution is 3%-8%.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. This invention significantly improves the overall strength of the composite nonwoven fabric by combining a biomass fiber layer with a micro-nano-scale rough surface structure to increase inter-fiber friction and cohesion with a high-strength synthetic fiber reinforcement layer that uses a three-dimensional weaving method to uniformly distribute the fibers in all directions to form a robust mesh structure. This unique base structure design enables the composite nonwoven fabric to withstand greater tensile and tear forces, making it less prone to damage in various application scenarios and extending its service life. Compared with traditional nonwoven fabrics, its tensile strength is increased by 50%-80%, and its tear strength is increased by 30%-50%.

[0028] 2. The antibacterial functional layer of this invention is composed of biomass nanofibers loaded with natural antibacterial components (such as tea polyphenols, artemisia extract, allicin, etc.) and inorganic antibacterial agents such as nano-silver particles. The natural antibacterial components have good biocompatibility and safety, and can effectively inhibit the growth of various bacteria and fungi. The nano-silver particles have broad-spectrum antibacterial properties and long-lasting antibacterial effects. The antibacterial agents are stably loaded on the surface of biomass nanofibers with a large specific surface area through physical adsorption and chemical bonding, forming a highly efficient and long-lasting antibacterial system. According to the test, the antibacterial rate of this composite nonwoven fabric against common bacteria such as Escherichia coli and Staphylococcus aureus reaches more than 99%, and the antibacterial performance still remains above 95% after multiple uses and washings.

[0029] 3. The composite nonwoven fabric of this invention uses a large amount of biomass materials such as wood pulp fiber, bamboo fiber, hemp fiber, polylactic acid, and polyhydroxyalkanoate. These materials can be decomposed by microorganisms in the natural environment and eventually converted into harmless substances such as carbon dioxide and water, which meets environmental protection requirements. Compared with traditional chemical fiber nonwoven fabrics, its biodegradation rate is significantly faster. It can begin to degrade significantly after being buried in the soil for 3-6 months, greatly reducing environmental pollution. Detailed Implementation

[0030] 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 a part of the embodiments of the present invention, and not all of the embodiments. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The present invention will describe the above technical solution in detail through the following embodiments:

[0032] Example 1

[0033] A composite nonwoven fabric, comprising:

[0034] The base layer, serving as the main supporting structure of the composite nonwoven fabric, is composed of a biomass fiber layer and a synthetic fiber reinforcing layer. The biomass fiber layer consists of one or more of wood pulp fiber, bamboo fiber, and hemp fiber, all of which possess good biodegradability and a certain degree of flexibility. Wood pulp fiber is widely available, inexpensive, and has good water absorption; bamboo fiber has natural antibacterial and bacteriostatic properties, and its fiber strength is high; hemp fiber is known for its high strength and good air permeability. By rationally mixing these biomass fibers, their respective advantages can be fully utilized. Furthermore, the surface of the biomass fiber layer forms a micro-nano-scale rough structure, increasing the friction and cohesion between the fibers.

[0035] The synthetic fiber reinforcement layer is composed of high-strength synthetic fibers such as aramid fibers and ultra-high molecular weight polyethylene fibers. These synthetic fibers have extremely high strength and modulus, which can significantly improve the overall strength of the base layer. Aramid fibers have excellent high temperature resistance and chemical corrosion resistance, and their high strength allows them to maintain structural stability in various harsh environments. Ultra-high molecular weight polyethylene fibers have extremely high strength and good wear resistance. The synthetic fiber reinforcement layer adopts a special weaving method, such as three-dimensional weaving, so that the fibers are evenly distributed in all directions to form a strong mesh structure that is tightly combined with the biomass fiber layer, providing strong support for the composite nonwoven fabric.

[0036] An antibacterial functional layer, disposed on the surface of a base layer, is composed of biomass nanofibers loaded with antibacterial agents. These biomass nanofibers are obtained by nano-processing cellulose or chitosan, possessing a large specific surface area, enabling efficient loading of antibacterial agents. The antibacterial agents include natural antibacterial components and inorganic antibacterial agents. The natural antibacterial components consist of one or more of tea polyphenols, Artemisia argyi extract, and allicin, while the inorganic antibacterial agents are composed of silver nanoparticles. The natural antibacterial components exhibit good biocompatibility and safety, effectively inhibiting the growth of various bacteria and fungi without harming the human body. The silver nanoparticles possess broad-spectrum antibacterial properties, inhibiting and killing almost all bacteria and viruses, with a long-lasting antibacterial effect. The antibacterial agents are loaded onto the surface of the biomass nanofibers through physical adsorption and chemical bonding, forming a stable antibacterial system. During the preparation process, by controlling the loading amount and distribution uniformity of the antibacterial agents, the antibacterial functional layer achieves highly efficient and long-lasting antibacterial performance.

[0037] The protective surface layer, covering the surface of the antibacterial functional layer, is composed of a biomass fiber film that has undergone waterproof and oil-proof treatment. The biomass fiber film is made of polylactic acid and polyhydroxyalkanoates. Biomass materials such as polylactic acid and polyhydroxyalkanoates have good biodegradability and mechanical properties, which can provide surface protection for the composite nonwoven fabric. By waterproofing and oil-proofing the biomass fiber film, a low surface energy protective film is formed on its surface, which can effectively prevent the intrusion of external liquids, oil stains and microorganisms, without affecting the breathability of the composite nonwoven fabric. The thickness of the protective surface layer is controlled within an appropriate range to ensure good protective performance without affecting the softness and comfort of the composite nonwoven fabric.

[0038] The mass ratio of the natural antibacterial component to the inorganic antibacterial agent in the antibacterial functional layer is (2-5):(1-3).

[0039] The aramid fiber or ultra-high molecular weight polyethylene fiber accounts for 60%-80% of the volume in the synthetic fiber reinforcement layer.

[0040] A method for manufacturing a composite nonwoven fabric includes the following steps:

[0041] Base layer preparation: Wood pulp fiber and bamboo fiber are selected and mixed in a mass ratio of 3:2. The mixed fibers are screened and washed to remove impurities. Then, the fibers are soaked in a solution containing 1% surfactant and 3% sodium hydroxide and treated at 60℃ for 2 hours. After treatment, the fibers are rinsed with water until neutral and dried at 80℃. Then, aramid fiber is selected and woven into a 0.5mm thick reinforcing layer using a three-dimensional weaving method. An appropriate amount of epoxy resin binder is added during the weaving process. The pretreated biomass fiber layer is placed on the synthetic fiber reinforcing layer and hot-pressed at 180℃ and 8MPa for 8 minutes to form the base layer.

[0042] Preparation of antibacterial functional layer: Biomass nanofibers were prepared by electrospinning using cellulose as raw material. Cellulose was dissolved in ionic liquid to prepare a 10% spinning solution. The spinning solution was sprayed into nanofibers by electrospinning equipment and collected on a receiving device. The prepared biomass nanofibers were soaked in a solution containing 5% tea polyphenols and 3% nano silver particles for 1.5 hours, and then dried at 60°C. The biomass nanofibers loaded with antibacterial agent were then uniformly coated on the surface of the base layer by spraying to form an antibacterial functional layer with a thickness of 8μm.

[0043] Preparation of protective surface layer: Polyhydroxyalkanoate is melt-extruded into a biomass fiber film with a thickness of 0.05 mm at an extrusion temperature of 180℃. After cooling and stretching, the biomass fiber film is immersed in a solution containing fluoropolymer waterproof and oil-repellent agents for 45 minutes. Then it is dried at 100℃. The waterproof and oil-repellent biomass fiber film is hot-pressed at 120℃ and 4MPa for 4 minutes and then laminated onto the surface of the antibacterial functional layer to form a protective surface layer.

[0044] Packaging: Finally, the prepared composite nonwoven fabric is cut, sorted, slit, and packaged.

[0045] In step five, the waterproof and oil-repellent agent is a fluoropolymer or organosilicon compound, and its mass fraction in the waterproof and oil-repellent treatment solution is 3%-8%.

[0046] Example 2

[0047] The only difference between this embodiment and Embodiment 1 is that: in this embodiment, hemp fibers are selected, screened and cleaned, then soaked in a solution containing 2% surfactant and 5% sodium hydroxide, treated at 60°C for 2 hours, rinsed with water until neutral, and dried at 80°C. All other conditions are the same.

[0048] Example 3

[0049] The only difference between this embodiment and Embodiment 1 is that: in this embodiment, hemp fibers are selected, screened, and washed, then soaked in a solution containing 0.5% surfactant and 2% sodium hydroxide, treated at 70°C for 1.5 hours, rinsed with water until neutral, and dried at 90°C. All other conditions are the same.

[0050] Example 4

[0051] The only difference between this embodiment and Embodiment 1 is that in this embodiment, the prepared biomass nanofibers are soaked in a solution containing 4% Artemisia argyi extract and 2% nano-silver particles for 1 hour, and then dried at 50°C. All other conditions are the same.

[0052] Comparative Example 1

[0053] The only difference between this comparative example and Example 1 is that the traditional meltblown-wood pulp composite nonwoven fabric preparation method is used in this comparative example, without adding a synthetic fiber reinforcement layer, while all other conditions are the same.

[0054] Comparative Example 2

[0055] The only difference between this comparative example and Example 1 is that the antibacterial functional layer in this comparative example is coated with a common antibacterial agent, while all other conditions are the same.

[0056] Comparative Example 3

[0057] The only difference between this comparative example and Example 1 is that the protective surface layer in this comparative example is not treated with waterproofing or oil resistance, while all other conditions are the same.

[0058] Comparative Example 4

[0059] The only difference between this comparative example and Example 1 is that this comparative example uses chemical fibers and does not contain biomass materials; all other conditions are the same.

[0060] According to Examples 1-4 and Comparative Examples 1-4 above, nonwoven fabric samples were prepared and their properties were tested:

[0061] I. Tensile Strength Test:

[0062] Test standard: Based on GB / T3923.1-2013 "Textiles - Tensile properties of fabrics - Part 1: Determination of breaking strength and elongation at break (strip method)";

[0063] Test process:

[0064] 1. Cut 5 longitudinal and 5 transverse test specimens from each sample, with a size of (200±1) mm × (50±1) mm;

[0065] 2. An electronic universal testing machine is used, with a clamping distance of 100mm and a tensile speed of 100mm / min;

[0066] 3. Record the breaking strength (N) of each specimen and calculate the average values ​​in the longitudinal and transverse directions, in N / 5cm.

[0067] II. Tear Strength Test:

[0068] Test standard: Based on GB / T3917.2-2009 "Textiles - Tear properties of fabrics - Part 2: Determination of tear strength of trousers specimens (single seam)"

[0069] Test process:

[0070] 1. Cut 5 longitudinal and 5 transverse trouser pattern samples from each sample, with an effective length of 100mm and a leg width of 30mm;

[0071] 2. An electronic universal testing machine is used, with a clamping distance of 75mm and a tensile speed of 100mm / min;

[0072] 3. Record the tear strength (N) of each sample and calculate the average values ​​in the longitudinal and transverse directions.

[0073] III. Antibacterial Rate Test (Escherichia coli, Staphylococcus aureus):

[0074] Test standard: Based on GB / T20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Vibration method"

[0075] Test process:

[0076] 1. Preparation of bacterial suspension: Escherichia coli (ATCC25922) and Staphylococcus aureus (ATCC6538) were cultured to the logarithmic growth phase and diluted with sterile physiological saline to (1.0-5.0) × 10⁻⁶. 5 CFU / mL;

[0077] 2. Sample preparation: Take 2.0g of sample, cut it into small pieces and put it into an Erlenmeyer flask. Add 20mL of bacterial suspension and shake (120r / min) for 18h (37℃).

[0078] 3. Viable cell count: Take 1 mL of the shaken bacterial solution, serially dilute it and spread it on nutrient agar medium, incubate at 37℃ for 24 h, and count the number of colonies.

[0079] 4. Calculate the antibacterial rate: Antibacterial rate (%) = [(number of colonies in the control group - number of colonies in the sample group) / number of colonies in the control group] × 100%.

[0080] IV. Antibacterial rate test after washing:

[0081] Test process:

[0082] 1. Refer to GB / T8629-2017 "Home Washing and Drying Procedures for Textile Testing", and adopt the AATCC135 standard washing procedure (water temperature 40℃±3℃, neutral detergent, liquor ratio 1:50, 5 washes).

[0083] 2. After washing, the samples were tested again according to the "antibacterial rate test" procedure, and the antibacterial rate after washing was calculated.

[0084] V. Biodegradation rate test (soil burial method):

[0085] Test standard: Refer to GB / T19277.1-2011 "Determination of final aerobic biodegradability of materials under controlled composting conditions - Part 1: General method"

[0086] Test process:

[0087] 1. Take 10g of sample (crushed to a particle size ≤5mm), mix with 1000g of humus soil (pH 6.5-7.5, moisture content 30%-40%), and place in a 25℃ constant temperature incubator;

[0088] 2. Samples were taken at 0 days, 30 days, 60 days and 90 days respectively, and the mass of the remaining samples was determined by gravimetric method;

[0089] 3. Calculate the biodegradation rate: Biodegradation rate (%) = [(initial mass - remaining mass) / initial mass] × 100%.

[0090] VI. Waterproofing Rating Test:

[0091] Testing standard: Based on the IPX5-IPX7 ratings in GB / T4208-2017 "Degrees of Protection Provided by Enclosures (IP Code)".

[0092] Test process:

[0093] 1. IPX5 rating: Using a nozzle with a diameter of 6.3 mm, spray water in all directions of the sample at a flow rate of 12.5 L / min from a distance of 3 m for 3 minutes;

[0094] 2. IPX6 rating: Use a nozzle with a diameter of 12.5 mm to spray water in all directions of the sample at a flow rate of 100 L / min from a distance of 3 m for 3 minutes;

[0095] 3. IPX7 rating: Immerse the sample in 1m deep water and let it stand for 30 minutes;

[0096] 4. Observe whether water seeps into the sample surface to determine the waterproof level (if there is no water seepage, it meets the standard).

[0097] VII. Oil resistance rating test:

[0098] Test standard: Based on AATCC 118-2013 "Oil resistance of fabrics: Hydrocarbon test solution method"

[0099] Test process:

[0100] 1. Use standard hydrocarbon test solutions of grades 1-8 (viscosity increasing), starting from grade 1, drop 0.05 mL of test solution onto the sample surface;

[0101] 2. Let stand for 30 seconds and observe whether the droplets penetrate (if no penetration occurs, pass this level and continue testing to a higher level).

[0102] 3. Record the highest impermeability level as the oil-resistant level.

[0103] The specific data are shown in Tables 1 and 2 below:

[0104]

[0105] Table 1

[0106]

[0107] Table 2

[0108] As can be seen from the data in the table above, the tensile strength and tear strength of Examples 1-4 are more than 50% higher than those of Comparative Example 1. This is due to the composite structure of "biomass fiber layer + three-dimensional woven synthetic fiber reinforcement layer" adopted in the base layer. The micro-nano rough surface increases the cohesion between fibers, and the synthetic fiber reinforcement layer forms a strong support network, making the material less prone to damage when subjected to tension and tear, and significantly extending its service life.

[0109] The antibacterial rates of Examples 1-4 and after washing are much higher than those of Comparative Example 2. The advantage stems from the "biomass nanofiber loaded antibacterial agent" design adopted for the antibacterial functional layer: the large specific surface area of ​​biomass nanofibers enables efficient loading of antibacterial agents, and the antibacterial agents are fixed through the dual action of physical adsorption and chemical combination, which solves the problem of easy loss of antibacterial components in traditional coating processes and ensures that the high-efficiency antibacterial effect is maintained after long-term use.

[0110] After waterproofing and oil-proofing treatment, Examples 1-4 achieved a waterproof rating of IPX6 (resisting strong water spray) and an oil-proof rating of 5-6, which is significantly better than Comparative Example 3. The biomass fiber film on the protective surface, after special treatment, forms a low surface energy protective film that can block the intrusion of liquids and oil stains, meeting the dual requirements of protection and comfort in medical, hygiene and other scenarios.

[0111] The 90-day biodegradation rate of Examples 1-4 is 63%-68%, which is much higher than that of Comparative Example 4. This is because a large amount of biomass materials such as wood pulp fiber, bamboo fiber, and polylactic acid are used. These materials can be decomposed by microorganisms in the natural environment and eventually transformed into harmless substances, which solves the "white pollution" problem of traditional chemical fiber nonwoven fabrics and is in line with the concept of environmental protection and sustainable development.

[0112] As can be seen from the comparison, the composite nonwoven fabric of the present invention, through the synergistic optimization of structural design and material selection, exhibits significant advantages in mechanical strength, antibacterial durability, protective performance, environmental protection, and overall balance, effectively solving the problem of outstanding single performance but insufficient overall performance in the prior art.

[0113] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A composite nonwoven fabric, characterized in that, include: The base layer is composed of a biomass fiber layer and a synthetic fiber reinforcement layer, and the surface of the biomass fiber layer forms a micro-nano-scale rough structure. An antibacterial functional layer is disposed on the surface of the base layer and is composed of biomass nanofibers loaded with antibacterial agents. The biomass nanofibers are obtained by nano-processing cellulose or chitosan. The protective surface layer, covering the surface of the antibacterial functional layer, is composed of a biomass fiber film that has been treated to be waterproof and oil-proof. The biomass fiber film is made of polylactic acid and polyhydroxyalkanoate. The synthetic fiber reinforcement layer is composed of aramid fibers and ultra-high molecular weight polyethylene fibers using a three-dimensional weaving method.

2. The composite nonwoven fabric as described in claim 1, characterized in that: The biomass fiber layer is composed of one or more of wood pulp fiber, bamboo fiber, and hemp fiber.

3. The composite nonwoven fabric as described in claim 1, characterized in that: The antibacterial agent includes natural antibacterial components and inorganic antibacterial agents. The natural antibacterial components are composed of one or more of tea polyphenols, artemisia argyi extract, and allicin. The inorganic antibacterial agents are composed of nano-silver particles.

4. The composite nonwoven fabric as described in claim 3, characterized in that: The mass ratio of the natural antibacterial component to the inorganic antibacterial agent in the antibacterial functional layer is (2-5):(1-3).

5. The composite nonwoven fabric as described in claim 3, characterized in that: The antibacterial agent is loaded onto the surface of the biomass nanofibers through physical adsorption and chemical bonding.

6. The composite nonwoven fabric as described in claim 1, characterized in that: The aramid fiber or ultra-high molecular weight polyethylene fiber accounts for 60%-80% of the volume in the synthetic fiber reinforcement layer.

7. A method for manufacturing a composite nonwoven fabric, applicable to the composite nonwoven fabric according to any one of claims 1-6, characterized in that: Includes the following steps: Step 1: After screening and washing the wood pulp fiber and bamboo fiber, soak them in a solution containing surfactant and sodium hydroxide for alkaline treatment, then rinse them with water until neutral and dry them to obtain the pretreated biomass fiber layer. Step 2: Aramid fibers and ultra-high molecular weight polyethylene fibers are woven in a three-dimensional braiding manner, and an adhesive is added during the weaving process to obtain a synthetic fiber reinforcement layer; Step 3: Using a hot-pressing composite process, the pretreated biomass fiber layer and synthetic fiber reinforcement layer are hot-pressed at 150-200℃ and 5-10MPa for 5-10 minutes to obtain the base layer; Step 4: Using cellulose as raw material, prepare biomass nanofibers using chemical or physical methods. Soak the prepared biomass nanofibers in a solution of natural antibacterial components and inorganic antibacterial agents for 1-2 hours, then dry them to obtain biomass nanofibers. Then, use spraying or scraping to uniformly coat the biomass nanofibers loaded with antibacterial agents onto the surface of the base layer to form an antibacterial functional layer with a thickness of 5-10 μm. Step 5: Polyhydroxyalkanoates are prepared into biomass fiber films by melt extrusion or solution casting, and then cooled and stretched. The biomass fiber films are then immersed in a solution containing waterproof and oil-repellent agents for 30-60 minutes, dried, and then hot-pressed onto the surface of the antibacterial functional layer using a hot-pressing composite process at 100-150℃ and 3-5MPa for 3-5 minutes to obtain composite nonwoven fabric. Step Six: Finally, the prepared composite nonwoven fabric is cut, sorted, slit, and packaged.

8. The method for manufacturing the composite nonwoven fabric as described in claim 7, characterized in that: In step one, the mass fraction of the surfactant treated with alkali is 0.5%-2%, the mass fraction of sodium hydroxide is 2%-5%, the treatment temperature is 50-70℃, and the treatment time is 1-3 hours.

9. The method for manufacturing the composite nonwoven fabric as described in claim 7, characterized in that: In step five, the waterproof and oil-repellent agent is a fluoropolymer or organosilicon compound, and its mass fraction in the waterproof and oil-repellent treatment solution is 3%-8%.

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