High-efficiency filtering spunlace nonwoven cloth with both flame-retardant and antibacterial functions and preparation method thereof

Abstract

The application provides a high-efficiency filtering water-jet non-woven fabric with both flame-retardant and antibacterial functions and a preparation method thereof, comprising a flame-retardant non-woven fabric layer, an antibacterial non-woven fabric layer and a base cloth layer, wherein the flame-retardant non-woven fabric layer is prepared by centrifugal spinning of a precursor PAA of polyimide obtained by dissolving pyromellitic dianhydride and 4,4-diamino diphenyl ether in N,N-dimethylformamide; the antibacterial non-woven fabric layer is prepared by a water-jet process using double-component fibers added with antibacterial master batches; and the base cloth layer is prepared by needling and electrostatic poling of flame-retardant polyester staple fibers. The water-jet non-woven fabric prepared by using polyimide with excellent flame-retardant performance as the flame-retardant layer, using double-component fibers added with antibacterial master batches as the antibacterial layer, and combining the needling process and the polyester base cloth layer treated by electrostatic poling has the functions of persistent flame retardation, antibiosis and high-efficiency filtration, and solves the problems of single function and short service period of the water-jet non-woven fabric.

Description

Technical Field

[0001] This invention relates to the field of spunlace nonwoven fabric technology, and in particular to a high-efficiency spunlace nonwoven filter fabric with both flame-retardant and antibacterial functions, and its preparation method. Background Technology

[0002] Nonwoven fabrics refer to sheet-like materials, webs, or mats made by bonding oriented or randomly arranged fibers together through friction, cohesion, or adhesion, or a combination of these methods. They do not include paper, woven fabrics, tufted fabrics, stitch-knitted fabrics with stitch-knitting yarns, or felted products made by wet-spun fulling. The fibers used can be natural or chemical fibers; they can be short fibers, filaments, or directly formed fibrous materials. Due to their short processing flow, high production speed, wide range of applicable fibers, multiple functions, and wide product applications, nonwoven fabrics are widely used in environmental filtration, medical, hygiene, health care, industry, agriculture, civil engineering, construction, household facilities, and various aspects of daily life.

[0003] Spunlace nonwoven fabric is made by spraying high-pressure micro-jet water onto one or more layers of fiber web, causing the fibers to entangle together and thus strengthening the web to a certain strength. The resulting fabric is called spunlace nonwoven fabric. Spunlace nonwoven fabric features flexible entanglement that does not affect the original characteristics of the fibers or damage them. Its appearance is closer to that of traditional textiles than other nonwoven materials. Furthermore, its high strength, low pilling, high moisture absorption, rapid moisture absorption, good breathability, soft hand feel, and good drape make it popular in the market.

[0004] Although spunlace nonwoven fabrics possess many advantages, functional spunlace nonwoven fabrics are relatively rare on the market. Patent CN114148057A discloses an antibacterial spunlace nonwoven fabric and its preparation method, comprising a hydrophobic nonwoven layer and a hydrophilic nonwoven layer. Antibacterial microbeads are present between the hydrophobic and hydrophilic nonwoven layers. The antibacterial microbeads are prepared by mixing antibacterial agents with silicone balls and then drying them. An adhesive web layer for fixing the antibacterial microbeads is present on the hydrophobic nonwoven layer. The preparation method involves first forming the hydrophilic and hydrophobic nonwoven layers, then pre-fixing the antibacterial microbeads with hot-melt adhesive short fibers after hot melting, and finally connecting the hydrophilic and hydrophobic nonwoven layers using a hydroentangling process. Although the patent endows spunlace nonwoven fabric with antibacterial properties, the antibacterial microbeads are made by mixing silica balls with antibacterial agents. Due to the limited adsorption capacity of the silica balls and the easy dissolution and short service life of the antibacterial agents, the spunlace nonwoven fabric cannot well meet the antibacterial requirements.

[0005] For the flame retardant function of spunlace nonwoven fabrics, flame retardant viscose fiber, flame retardant polyester fiber, or aramid 1313 are mostly used to make them flame retardant. However, the flame retardant performance of these conventional flame retardant fibers is generally poor, and the flame retardant level cannot reach B2 level. Therefore, the flame retardant spunlace nonwoven fabrics prepared in this way have low flame retardant performance and require additional flame retardant post-treatment, which increases the cost, changes the original performance of the spunlace nonwoven fabric, and cannot meet the needs of the application environment, such as buildings, offices, fire protection facilities, hospitals, etc.

[0006] In view of this, it is necessary to design an improved high-efficiency spunlace nonwoven filter with both flame-retardant and antibacterial functions and its preparation method to solve the above problems. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide a high-efficiency spunlace nonwoven fabric with both flame retardant and antibacterial functions and its preparation method, thereby solving the technical problems of single functionality and short service life of existing spunlace nonwoven fabrics.

[0008] To achieve the above objectives, the present invention provides a method for preparing a high-efficiency spunlace nonwoven filter fabric that simultaneously possesses flame-retardant and antibacterial functions, comprising the following steps:

[0009] S1. Pyromellitic anhydride (PMDA) and 4,4-diaminodiphenyl ether (ODA) are dissolved in N,N-dimethylformamide (DMF) at a molar ratio of (1.01~1.02):1 to prepare a polyimide (PI) precursor PAA (polyamic acid) solution, and a flame-retardant nonwoven fabric layer is prepared by centrifugal spinning process;

[0010] S2. An antibacterial nonwoven fabric layer is prepared by hydroentangling two-component fibers with 3-6% added antibacterial masterbatch. The two-component fibers are PE (polyethylene) / PP (polypropylene) or PP (polypropylene) / PET (polyethylene terephthalate).

[0011] S3. Flame-retardant polyester staple fibers are needle-punched and electrostatically electret treated to obtain the base fabric layer;

[0012] S4. The prepared flame-retardant nonwoven fabric layer, antibacterial nonwoven fabric layer and base fabric layer are composited by hydroentangling process, wherein the antibacterial nonwoven fabric layer is the middle layer, and after drying, a high-efficiency filter hydroentangled nonwoven fabric with both flame-retardant and antibacterial functions is obtained.

[0013] As a further improvement of the present invention, in step S1, the sum of the solid contents of pyromellitic anhydride and 4,4-diaminodiphenyl ether and the amount of N,N-dimethylformamide are in the ratio of (20-25):(75-80).

[0014] Furthermore, the centrifugal spinning process has a spinning speed of 3500-3600 rpm, a spinning needle size of 0.15-0.30 mm, and a collection distance of 5-7 cm.

[0015] The flame-retardant nonwoven fabric layer has a fiber diameter of 3–5 μm and a basis weight of 20–25 g / m². 2 .

[0016] As a further improvement of the present invention, in step S2, the ratio of each component in the bicomponent fiber is (30:70) to (70:30).

[0017] Furthermore, the method for preparing the antibacterial masterbatch is as follows: metal ions Ag, Zn, and Cu are combined with zeolite through ion exchange to obtain silver zeolite complex, zinc zeolite complex, and copper zeolite complex; the silver zeolite complex, zinc zeolite complex, and copper zeolite complex are added to a low-melting-point polymer solution at a mass ratio of 1:1:1; and the solution is dried to obtain the antibacterial masterbatch; the low-melting-point polymer is low-melting-point polyester fiber or low-melting-point polyester fiber.

[0018] The antibacterial nonwoven fabric layer has a fiber diameter ≥20μm and a basis weight of 10~15g / m². 2 .

[0019] As a further improvement of the present invention, in step S3, the relevant parameters of the needle punching process and electrostatic electret treatment are: the number of cross-laid layers is 6 to 8; the needle punching density is 70 to 80 needles / m. 2 The hot rolling temperature is 80–90℃, and the pressure is 0.1–0.6 MPa; the electrostatic electret voltage is 30–40 kV; the fiber diameter of the base fabric layer is 10–25 μm, and the basis weight is 30–35 g / m². 2 .

[0020] As a further improvement of the present invention, in step S4, the hydroentangling pressure of the hydroentangling process is 50-60 MPa, the hydroentangling speed is 100-120 m / s, and the hydroentangling distance is 10-15 mm.

[0021] The present invention also provides a high-efficiency spunlace nonwoven fabric with both flame retardant and antibacterial functions, which is prepared by the above-mentioned method for preparing the high-efficiency spunlace nonwoven fabric with both flame retardant and antibacterial functions.

[0022] The beneficial effects of this invention are:

[0023] 1. This invention provides a high-efficiency spunlace nonwoven fabric with both flame-retardant and antibacterial functions, and its preparation method. The fabric includes a flame-retardant nonwoven layer, an antibacterial nonwoven layer, and a base fabric layer. The flame-retardant nonwoven layer is obtained by centrifugal spinning of polyimide precursor PAA obtained by dissolving pyromellitic anhydride and 4,4-diaminodiphenyl ether in N,N-dimethylformamide. The antibacterial nonwoven layer is obtained by hydroentangling bicomponent fibers with added antibacterial masterbatch. The base fabric layer is prepared by needle punching and electrostatic electret treatment of flame-retardant polyester staple fibers. Finally, the flame-retardant nonwoven layer, the antibacterial nonwoven layer, and the base fabric layer are connected by hydroentangling. This invention uses polyimide with excellent flame-retardant properties as a flame-retardant layer, bicomponent fibers with added antibacterial masterbatch as an antibacterial layer, and combines it with a polyester base fabric layer with needle punching and electrostatic electret treatment. The resulting spunlace nonwoven fabric has long-lasting flame retardant, antibacterial and high-efficiency filtration functions, solving the problems of single function and short service life of previous spunlace nonwoven fabrics.

[0024] 2. The polyimide nonwoven fabric produced by the present invention through centrifugal spinning process retains the structure of polyimide itself, ensuring excellent flame retardant performance. Furthermore, because the nonwoven fabric adopts spiral descent and planar collection, the entanglement between its fibers is relatively loose and the porosity is large, which can better filter large-diameter particles. While possessing flame retardant performance, it can also improve the filtration performance of composite nonwoven fabric.

[0025] 3. Zeolite is a general term for zeolite group minerals, mainly composed of five parts: SiO2, Al2O3, H2O, alkali metals, and alkaline earth metal ions. The silicon-oxygen tetrahedra and aluminum-oxygen tetrahedra constitute the three-dimensional framework structure of zeolite. The loose and easily replaceable bonds between alkali metals, alkaline earth metals, and water molecules give zeolite excellent adsorption and ion exchange properties. The framework structure of zeolite is very stable and remains unchanged regardless of adsorption, desorption, or ion exchange. Antibacterial masterbatches prepared by adding copper-zeolite complexes, silver-zeolite complexes, and zinc-zeolite complexes (formed by combining copper, silver, and zinc elements with zeolite) to polymer solutions, and then adding them to bicomponent fibers, avoids the defects of "dissolution" and short shelf life that occur after adding traditional antibacterial agents. The antibacterial nonwoven fabric prepared by hydroentangling process gives the composite nonwoven fabric good antibacterial properties and suitable stiffness.

[0026] 4. In the preparation process of the nonwoven fabric of the present invention, the base fabric layer is made of flame-retardant polyester short fibers, which are prepared into a base fabric nonwoven fabric layer by needle punching process. Then, the electrostatic electret treatment technology is used to make the nonwoven fabric carry a large amount of charge. By improving its electrostatic adsorption, the high filtration performance of the nonwoven fabric is achieved. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the spunlace nonwoven fabric of the present invention.

[0028] Figure 2 This is a schematic diagram of the antibacterial masterbatch loaded on fibers in Embodiment 1 of the present invention.

[0029] Figure 3 This is a schematic diagram illustrating the antibacterial principle of the present invention.

[0030] Figure Labels

[0031] 1. Spunlace nonwoven fabric; 11. Flame-retardant nonwoven fabric layer; 12. Antibacterial nonwoven fabric layer; 13. Base fabric layer. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] It should also be noted that, in order to avoid obscuring the invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0034] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0035] This invention provides a method for preparing a high-efficiency spunlace nonwoven filter fabric that simultaneously possesses flame-retardant and antibacterial functions, comprising the following steps:

[0036] S1. Pyromellitic anhydride and 4,4-diaminodiphenyl ether were dissolved in N,N-dimethylformamide at a molar ratio of (1.01~1.02):1 to prepare a polyimide precursor PAA solution, which was then used to prepare a flame-retardant nonwoven fabric layer by centrifugal spinning.

[0037] Specifically, pyromellitic anhydride and 4,4-diaminodiphenyl ether are dissolved in N,N-dimethylformamide in a water bath at 85–95°C to obtain a polyimide precursor PAA solution. The preferred ratio of the sum of the solid contents of pyromellitic anhydride and 4,4-diaminodiphenyl ether to the amount of N,N-dimethylformamide is (20–25):(75–80). The specific parameters for the centrifugal spinning process are: a spinning speed of 3500–3600 rpm, a spinning needle size of 0.15–0.30 mm, and a collection distance of 5–7 cm. The resulting flame-retardant nonwoven fabric layer has a fiber diameter of 3–5 μm and a basis weight of 20–25 g / m². 2 .

[0038] S2. An antibacterial nonwoven fabric layer is prepared by hydroentangling bicomponent fibers with 3-6% added antibacterial masterbatch. The bicomponent fibers are PE / PP or PP / PET.

[0039] Specifically, the ratio of each component in the bicomponent fiber is (30:70) to (70:30); the preparation method of the antibacterial masterbatch is as follows: metal ions Ag, Zn, and Cu are combined with zeolite through ion exchange to obtain silver zeolite complex, zinc zeolite complex, and copper zeolite complex. The silver zeolite complex, zinc zeolite complex, and copper zeolite complex are added to a low-melting-point polymer solution at a mass ratio of 1:1:1, and dried to obtain the antibacterial masterbatch; wherein, the low-melting-point polymer is preferably low-melting-point polyester fiber or low-melting-point polyester fiber. The amount of antibacterial masterbatch added is controlled at 3-6%, and it is uniformly added to the core layer and sheath layer of the bicomponent fiber.

[0040] The resulting antibacterial nonwoven fabric layer has a fiber diameter ≥20μm and a basis weight of 10–15g / m². 2 .

[0041] S3. Flame-retardant polyester staple fibers are needle-punched and electrostatically electret treated to obtain the base fabric layer.

[0042] Specifically, the base fabric layer is prepared from flame-retardant polyester staple fibers through opening, carding, cross-laying, needle punching, hot rolling, and electrostatic electret treatment. The relevant parameters are: 6-8 cross-laying layers; and a needle punching density of 70-80 needles / m². 2 The hot rolling temperature is 80–90℃, and the pressure is 0.1–0.6 MPa; the electrostatic electret voltage is 30–40 kV; the fiber diameter of the resulting base fabric layer is 10–25 μm, and the basis weight is 30–35 g / m². 2 .

[0043] S4. The prepared flame-retardant nonwoven fabric layer, antibacterial nonwoven fabric layer, and base fabric layer are composited using a hydroentangling process, with the antibacterial nonwoven fabric layer as the intermediate layer. After drying, a high-efficiency filter hydroentangled nonwoven fabric with both flame-retardant and antibacterial functions is obtained, the structure of which is as follows: Figure 1 As shown.

[0044] Specifically, the prepared flame-retardant nonwoven fabric layer, antibacterial nonwoven fabric layer, and base fabric layer are laid flat on the web-laying curtain of a rotary drum hydroentangling equipment. The three layers of nonwoven fabric are then composited through a hydroentangling process, resulting in intertwined fibers to form a composite hydroentangled nonwoven fabric. This nonwoven fabric is then dried in an oven to obtain a high-efficiency filter hydroentangled nonwoven fabric with both flame-retardant and antibacterial functions. The hydroentangling pressure is preferably 50–60 MPa, the hydronephrite jet velocity is preferably 100–120 m / s, and the hydronephrite jet action distance is preferably 10–15 mm.

[0045] The preparation method of the high-efficiency spunlace nonwoven filter fabric with both flame-retardant and antibacterial functions provided by the present invention will be described below with reference to specific embodiments.

[0046] Example 1

[0047] Example 1 provides a method for preparing a high-efficiency spunlace nonwoven filter fabric that simultaneously possesses flame-retardant and antibacterial functions, comprising the following steps:

[0048] S1. PMDA, ODA, and DMF were stirred in a water bath at 90℃ for 3 hours to obtain a polyimide precursor PAA solution, wherein the molar ratio of PMDA to ODA was 1.01:1, the sum of the solid contents of PMDA and ODA to the amount of DMF was 20:80, and the stirring speed was 200 rpm. The obtained solution was centrifuged at a spinning speed of 3500 rpm, a spinning needle of 0.21 mm, and a collection distance of 6 cm to obtain a flame-retardant nonwoven fabric layer.

[0049] S2. An antibacterial nonwoven fabric layer is obtained by hydroentangling PE / PP with 3% added antibacterial masterbatch, such as... Figure 2 As shown, the PE:PP ratio is 30:70; the preparation method of the antibacterial masterbatch is as follows: zeolite is placed in AgNO3 solution, Ag... + Alkali metal ions are stably bound to zeolite pores through ion exchange. After 1 hour, the zeolite complex is removed, washed, and dried to obtain a silver zeolite complex. Zinc and copper zeolite complexes are prepared using the same method. The silver, zinc, and copper zeolite complexes are added to 4080 fiber in a 1:1:1 ratio, stirred evenly, and then dried to obtain an antibacterial masterbatch. A schematic diagram of its antibacterial mechanism is shown below. Figure 3 As shown.

[0050] S3. Flame-retardant polyester staple fibers are needle-punched and electrostatically electret treated to obtain the base fabric layer. The relevant parameters are: 6 cross-laid layers; needle-punching density of 70 needles / m². 2 The hot rolling temperature is 85℃, the pressure is 0.5MPa, and the electrostatic electret voltage is 35kV.

[0051] S4: The flame-retardant nonwoven fabric layer and the base fabric layer are horizontally unwound using two unwinding rollers, while the antibacterial nonwoven fabric layer is horizontally unwound using a hydroentanglement equipment unwinding roller. The positions of the three unwinding rollers are as follows: the flame-retardant nonwoven fabric layer unwinding roller is on top, the antibacterial nonwoven fabric layer unwinding roller is in the middle, and the base fabric layer unwinding roller is at the bottom, forming a sandwich structure for composite fabric. The three-layer composite nonwoven fabric is hydroentangled simultaneously using a hydroentanglement process, with 8 to 10 hydroentanglements on both sides. In the hydroentanglement process, the hydroentanglement distance is 10cm, the hydroentanglement pressure is 50MPa, and the hydroentanglement speed is 100m / s. The fibers of the three layers become intertwined and then dried to obtain a high-efficiency filter hydroentangled nonwoven fabric with both flame-retardant and antibacterial functions.

[0052] Example 2 and Comparative Examples 1-2

[0053] Example 2 and Comparative Examples 1-2 respectively provide a method for preparing a high-efficiency spunlace nonwoven filter with both flame retardant and antibacterial functions. Compared with Example 1, the only difference is that the molar ratio of PMDA to ODA is different, which is 1.02:1, 1:1 and 1.03:1 respectively. Other experimental parameters and conditions are basically the same as those in Example 1, and will not be repeated here.

[0054] Example 3 and Comparative Examples 3-4

[0055] Example 3 and Comparative Examples 3-4 respectively provide a method for preparing a high-efficiency spunlace nonwoven filter fabric with both flame retardant and antibacterial functions. Compared with Example 1, the only difference is the amount of antibacterial masterbatch added, which is 6%, 2%, and 7%, respectively. Other experimental parameters and conditions are basically the same as those in Example 1, and will not be repeated here.

[0056] The spunlace nonwoven fabrics prepared in each embodiment and comparative example were tested for flame retardancy, antibacterial properties, and filtration performance. The flame retardancy (oxygen index) test method was based on the national standard GB 8624-2012; the antibacterial properties (Escherichia coli and Staphylococcus aureus) test method was based on the national standard GB / T 20944.3-2008 oscillation method; and the filtration performance test method was based on EN ISO 29463-3 (test flow rate 32 L / min, test particles: NaCl, particle size: 0.3 μm). It should be noted that the flame retardancy test standard specifies an oxygen index (LOI) ≥ 32% for grade B1, and the antibacterial performance test standard specifies an antibacterial rate ≥ 70% for Escherichia coli and Staphylococcus aureus, indicating that the fabric possesses antibacterial function. The test results are as follows:

[0057] Table 1. Performance test results of the examples and comparative examples.

[0058]

[0059] As can be seen from the table, the products of Examples 1, 2 and 3 all have an oxygen index (LOI) >32%, an inhibition rate of ≥99.95% against Escherichia coli and Staphylococcus aureus, and a filtration efficiency >99.5% for Examples 1-3 and Comparative Examples 1-4, with a resistance <30Pa. Compared with Example 1, Comparative Examples 1 and 2 adjusted the molar ratio of PMDA. As shown in Comparative Example 1, when the molar ratio of PMDA is low, the intermolecular bonding of the mixed solution is reduced, and the structure is incomplete, thus affecting its flame retardant effect. As shown in Comparative Example 2, when the molar ratio of PMDA is high, the intermolecular bonding of the mixed solution is overloaded, and the structure is deformed, which also affects its flame retardant effect. Compared with Example 1, Comparative Examples 3 and 4 adjusted the amount of antibacterial masterbatch added. As shown in Comparative Example 3, when the amount of antibacterial masterbatch added is only 2%, there are very few antibacterial particles attached to the bicomponent fibers, and the retention rate of pores between fibers is too high, resulting in poor antibacterial performance. As shown in Comparative Example 4, when the amount of antibacterial masterbatch added is 7%, there are too many antibacterial particles loaded inside and on the surface of the fibers, and each pore of the fiber is filled with antibacterial particles, affecting the original antibacterial performance and reducing its antibacterial effect.

[0060] In summary, this invention provides a high-efficiency spunlace nonwoven fabric with both flame-retardant and antibacterial functions, and its preparation method. The fabric comprises a flame-retardant nonwoven layer, an antibacterial nonwoven layer, and a base fabric layer. The flame-retardant nonwoven layer is formed by centrifugal spinning of PAA precursors obtained from the dissolution of pyromellitic anhydride and 4,4-diaminodiphenyl ether in N,N-dimethylformamide. The antibacterial nonwoven layer is formed by spunlace of bicomponent fibers with added antibacterial masterbatch. The base fabric layer is prepared from flame-retardant polyester staple fibers through needle punching and electrostatic electret treatment. This invention, by using polyimide with excellent flame-retardant properties as the flame-retardant layer, bicomponent fibers with added antibacterial masterbatch as the antibacterial layer, and combining this with a polyester base fabric layer treated by needle punching and electrostatic electret treatment, produces a spunlace nonwoven fabric with durable flame retardancy, antibacterial properties, and high-efficiency filtration, solving the problems of single-function and short service life of spunlace nonwoven fabrics.

[0061] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a high-efficiency spunlace nonwoven filter fabric with both flame-retardant and antibacterial functions, characterized in that, Includes the following steps: S1. A polyimide precursor PAA solution is prepared by dissolving pyromellitic anhydride and 4,4-diaminodiphenyl ether in N,N-dimethylformamide at a molar ratio of (1.01~1.02):

1. The PAA solution is then used to prepare a flame-retardant nonwoven fabric layer via centrifugal spinning. The centrifugal spinning process involves a spinning speed of 3500~3600 rpm, a spinning needle size of 0.15~0.30 mm, and a collection distance of 5~7 cm. The fiber diameter of the flame-retardant nonwoven fabric layer is 3~5 μm. S2. An antibacterial nonwoven fabric layer is prepared by hydroentangling bicomponent fibers with 3-6% added antibacterial masterbatch. The bicomponent fibers are PE / PP or PP / PET. The fiber diameter of the antibacterial nonwoven fabric layer is ≥20μm. The ratio of each component in the bicomponent fiber is (30:70) to (70:30); The method for preparing the antibacterial masterbatch is as follows: metal ions Ag, Zn, and Cu are combined with zeolite through ion exchange to obtain silver zeolite complex, zinc zeolite complex, and copper zeolite complex. The silver zeolite complex, zinc zeolite complex, and copper zeolite complex are added to a low-melting-point polymer solution at a mass ratio of 1:1:

1. After drying, the antibacterial masterbatch is obtained. The low-melting-point polymer is a low-melting-point polyester fiber. S3. Flame-retardant polyester staple fibers are needle-punched and electrostatically electret treated to obtain a base fabric layer; the fiber diameter of the base fabric layer is 10~25μm; S4. The prepared flame-retardant nonwoven fabric layer, antibacterial nonwoven fabric layer and base fabric layer are composited by hydroentangling process. The antibacterial nonwoven fabric layer is the middle layer. The hydroentangling pressure is 50~60MPa, the water jet speed is 100~120m / s, and the water jet action distance is 10~15mm. After drying, a high-efficiency filter hydroentangled nonwoven fabric with both flame-retardant and antibacterial functions is obtained.

2. The method for preparing the high-efficiency spunlace nonwoven filter fabric with both flame-retardant and antibacterial functions according to claim 1, characterized in that, In step S1, the ratio of the sum of the solid contents of pyromellitic anhydride and 4,4-diaminodiphenyl ether to the amount of N,N-dimethylformamide is (20~25):(75~80).

3. The method for preparing the high-efficiency spunlace nonwoven filter fabric with both flame-retardant and antibacterial functions according to claim 1, characterized in that, The weight of the flame-retardant nonwoven fabric layer is 20~25 g / m². 2 .

4. The method for preparing the high-efficiency spunlace nonwoven filter fabric with both flame-retardant and antibacterial functions according to claim 1, characterized in that, The basis weight of the antibacterial nonwoven fabric layer is 10~15g / m². 2 .

5. The method for preparing the high-efficiency spunlace nonwoven filter fabric with both flame-retardant and antibacterial functions according to claim 1, characterized in that, In step S3, the relevant parameters for the needle punching process and electrostatic electret treatment are: the number of cross-laid layers is 6 to 8; the needle punching density is 70 to 80 needles / m. 2 The hot rolling temperature is 80~90℃, and the pressure is 0.1~0.6MPa; the electrostatic electret voltage is 30~40kV; the basis weight of the base fabric layer is 30~35g / m². 2 .

6. A high-efficiency spunlace nonwoven filter fabric that simultaneously possesses flame-retardant and antibacterial functions, characterized in that, The high-efficiency spunlace nonwoven fabric with both flame-retardant and antibacterial functions is prepared by the method described in any one of claims 1-5.

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