Nylon-based efficient sewage treatment filter bag and preparation method thereof

Abstract

The invention relates to the technical field of sewage treatment filter bags, in particular to a nylon-based efficient sewage treatment filter bag and a preparation method thereof, and the nylon-based efficient sewage treatment filter bag is prepared from the following raw materials in parts by weight: 40-55 parts of high-strength nylon 6 fiber; 5-12 parts of a polytetrafluoroethylene microporous film; 12 to 18 parts of polyvinylidene fluoride fiber; 8-15 parts of nano zinc oxide modified polyester fiber; 5-10 parts of ultra-high molecular weight polyethylene fiber; 0.5 to 3 parts of silicon carbide whisker; 0.1 to 0.8 part of perfluoroalkyl silane; 1.2 to 3 parts of a hydrophilic polyvinylpyrrolidone polymer; 0.3 to 1.5 parts of fumed silica; 0.6 to 2 parts of zirconium phosphate silver-loaded ion powder; 3 to 8 parts of polyether-ether-ketone hot melt adhesive fiber; and 2-6 parts of cerium-based stabilized zirconia fiber. According to the invention, the nylon-based composite material is taken as a core, surface modification, structure enhancement and slow release technologies are fused, and the advantages of high-efficiency interception, low resistance flux and long-period stability of sewage treatment are synchronously realized on the premise of maintaining industrial-grade cost.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment filter bags, in particular to a nylon-based high-efficiency sewage treatment filter bag and a preparation method thereof. Background Art

[0002] Filter bags are bag-type filter elements made of fabric or porous materials. They physically separate suspended particles, colloids, and microorganisms from wastewater. They are primarily used in industrial wastewater treatment, municipal wastewater deep purification, circulating cooling water systems, and food processing wastewater reuse. They serve as core units for pretreatment or fine filtration, effectively ensuring water quality stability in subsequent processes.

[0003] Traditional filter bags are often made of single fibers such as polypropylene and polyester that are needle-punched into felt. Although they have cost advantages, they have inherent defects: the deep filtration structure is easily clogged by sticky impurities and difficult to clean thoroughly; the flux drops sharply when the filtration accuracy is improved, and the filter bags need to be replaced frequently; the chemical resistance is limited and they are easily degraded and broken in strong acid and alkali environments; insufficient mechanical strength makes them easy to break under high pressure differences, which greatly increases operation and maintenance costs and the burden of waste disposal.

[0004] Based on this, the present invention provides a nylon-based high-efficiency sewage treatment filter bag and a preparation method thereof to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a nylon-based high-efficiency sewage treatment filter bag and a preparation method thereof, so as to solve the problems mentioned in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a nylon-based high-efficiency sewage treatment filter bag, which is composed of the following raw materials in parts by weight: high-strength nylon 6 fiber: 40-55 parts; polytetrafluoroethylene microporous film: 5-12 parts; polyvinylidene fluoride fiber: 12-18 parts; nano zinc oxide modified polyester fiber: 8-15 parts; ultra-high molecular weight polyethylene fiber: 5-10 parts; silicon carbide whisker: 0.5-3 parts; perfluoroalkyl silane: 0.1-0.8 parts; hydrophilic polyvinyl pyrrolidone polymer: 1.2-3 parts; fumed silica: 0.3-1.5 parts; zirconium phosphate loaded silver ion powder: 0.6-2 parts; polyetheretherketone hot-melt bonding fiber: 3-8 parts; cerium-based stabilized zirconia fiber: 2-6 parts.

[0008] Preferably, the polytetrafluoroethylene microporous film is prepared by subjecting a polytetrafluoroethylene dispersion to electric field-assisted phase separation in a cryogenic environment of -30°C to -15°C, and has a pore size uniformity of ±0.5 μm.

[0009] Preferably, the nano-zinc oxide modified polyester fiber is prepared by depositing polyester chips in a vacuum plasma reactor with a power density of 0.8-1.2 W / cm 3 with zinc organic precursors, and the particle size of the zinc oxide nanoparticles is ≤35 nm.

[0010] Preferably, the silicon carbide whisker is prepared by laser-induced vapor deposition of silicon carbide precursors in a high gravity rotating bed, and the length-diameter ratio of the whisker is 35-50:1.

[0011] Preferably, the perfluoroalkylsilane is prepared by ultrasonic catalytic hydrosilylation of long-chain fluorocarbon compounds in a critical carbon dioxide fluid, and the fluorine content is ≥72 wt%.

[0012] Preferably, the silver ion-loaded zirconium phosphate powder is prepared by photochemical silver ion anchoring of a nano-zirconium phosphate carrier in a micro-channel reactor, and the silver ion loading capacity is 0.18-0.25 mmol / g.

[0013] Preferably, the cerium-based stabilized zirconia fiber is prepared by cold directional spinning of zirconia sol in a static magnetic field with a strength of 0.7-1.2 T, and the cerium doping amount is 5.0±0.3 mol%.

[0014] Preferably, the hydrophilic polyvinylpyrrolidone polymer is prepared by free radical gradient polymerization of N-vinylpyrrolidone in supercritical water, and the molecular weight distribution index is ≤1.15.

[0015] The present application also provides a preparation method of a nylon-based high-efficiency sewage treatment filter bag, comprising the following steps:

[0016] S1. 40-55 parts of high-strength nylon 6 fiber, 12-18 parts of polyvinylidene fluoride fiber, 8-15 parts of nano-zinc oxide modified polyester fiber, and 5-10 parts of ultra-high molecular weight polyethylene fiber are put into a double-screw vortex blender; 0.3-1.5 parts of fumed silica is injected as a pore stabilizer under the protection of inert gas with an argon purity of ≥99.999% and a flow rate of 15 L / min, and 0.5-3 parts of silicon carbide whisker prepared by laser-induced vapor deposition is added simultaneously to enhance wear resistance; the fiber web is sprayed out through a slit-type melt-blowing die with a die lip gap of 0.18±0.02 mm and a drawing air speed of 80 m / s, and is instantaneously shaped by a-30℃ cryogenic roller to form a pollution-containing layer-supporting layer composite base felt;

[0017] S2. 5-12 parts of polytetrafluoroethylene microporous film are placed on a constant tension unwinding machine; in a clean room with a temperature of 23±0.5℃ and a humidity of ≤30%, a target material distance of 100±5 mm, a sputtering power of 8 kW, and a vacuum degree of 5×10-3 Pa aThe magnetron sputtering spray equipment evenly deposits 0.1 to 0.8 parts of perfluoroalkylsilane synthesized from intercritical carbon dioxide fluid on the membrane surface to form a super-hydrophobic coating; the coating is then cross-linked and cured by electron beam irradiation.

[0018] S3. Dissolve 1.2 to 3 parts of supercritical water free radical polymerized polyvinyl pyrrolidone polymer in ultrapure water to form a 12 wt% solution, and inject it into the deep layer of the composite base felt obtained in step S1 through a high-pressure impregnation tank at a pressure of 3.5 ± 0.2 MPa and a temperature of 60 ° C; gradient dehydration in a synchrotron radiation drying oven, infrared wavelength 2.5 to 5 μm, energy flux density 1.2 kW / m 2 , so that the hydrophilic agent forms nano-scale water channels in the gaps between the fibers; 0.6 to 2 parts of microchannel photochemically anchored zirconium phosphate loaded silver ion powder are embedded into the base felt using an air flow carrying method with a carrier gas temperature of 150°C and a flow rate of 8m / s;

[0019] S4. Lay 2 to 6 parts of static magnetic field freeze-spun cerium-stabilized zirconia fibers and 3 to 8 parts of polyetheretherketone hot-melt bonding fibers on the bottom of the hot pressing mold, with a cerium doping amount of 5.0 ± 0.3 mol%; superimpose the functionalized base felt treated in step S3 and the film prepared in step S2, and feed it into a two-stage hot press:

[0020] First-stage hot pressing: temperature 310±5℃, pressure 12MPa, holding time 90 seconds, activate the polyetheretherketone bonding phase;

[0021] Secondary hot pressing: temperature 280±3℃, pressure 25MPa, time 120 seconds, to achieve zero-porosity composite;

[0022] Rapid cooling in liquid nitrogen quenching device at -196℃, cooling rate ≥150℃ / s;

[0023] S5. The composite filter material is wound onto a high-gravity rotating bed with a centrifugal factor of 350 ± 10 g and a rotation speed of 8500 rpm. Dynamic heat tension homogenization is performed by introducing 120°C saturated steam for 60 minutes to eliminate internal stress and improve dimensional stability. The composite filter material is then formed into filter bags using a laser cutting system with a wavelength of 1064 nm, a pulse energy of 50 mJ, and a cutting accuracy of ±0.01 mm.

[0024] Preferably, the screw speed of the twin-screw vortex blender in step S1 is 220±10 rpm, and the temperature zones are set in four stages: 195°C, 210°C, 225°C, and 205°C.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The application reduces the risk of blockage from the source by synergistically inhibiting the adhesion of oil stains and the breeding of bacterial membranes through the surface hydrophobic film and internal hydrophilic channel, and long-acting bacteria inhibition by slow-release silver ions; the wear-resistant framework enhanced by silicon carbide whiskers and the high-temperature-resistant cerium-based zirconia fiber support each other to give the filter bag the ability to resist high-pressure impact and greatly extend the service life; high-precision high-flux separation is achieved through the ultra-uniform microporous membrane to avoid the compromise between precision and flux; a multiple chemical barrier is formed by polyvinylidene fluoride fiber and perfluoro coating to resist strong corrosive media and high-temperature environment, expanding the boundary of industrial wastewater treatment. In summary, the application takes nylon-based composite material as the core, combines surface modification, structure enhancement and slow-release technology, and simultaneously realizes efficient interception, low resistance flux and long-period stability of wastewater treatment on the premise of maintaining industrial-grade cost, providing an innovative solution for high-difficulty wastewater treatment and resource recycling. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0028] I. Materials

[0029] The application provides a nylon-based efficient wastewater treatment filter bag. The components of the nylon-based efficient wastewater treatment filter bag material are not described and are all commercially available.

[0030] The nylon-based efficient wastewater treatment filter bag is composed of the following raw materials in parts by weight: high-strength nylon 6 fiber: 40-55 parts; polytetrafluoroethylene microporous membrane: 5-12 parts; polyvinylidene fluoride fiber: 12-18 parts; nano-zinc oxide modified polyester fiber: 8-15 parts; ultra-high molecular weight polyethylene fiber: 5-10 parts; silicon carbide whisker: 0.5-3 parts; perfluoroalkylsilane: 0.1-0.8 parts; hydrophilic polyvinylpyrrolidone polymer: 1.2-3 parts; fumed silica: 0.3-1.5 parts; silver ion-loaded zirconium phosphate powder: 0.6-2 parts; polyether ether ketone hot melt adhesive fiber: 3-8 parts; and cerium-based stabilized zirconia fiber: 2-6 parts.

[0031] It should be further noted that the polytetrafluoroethylene microporous membrane is prepared by electric field-assisted phase separation of polytetrafluoroethylene dispersion liquid in a deep cold environment at-30℃ to-15℃, and the pore size uniformity is ±0.5μm.

[0032] It should be further noted that the nano-zinc oxide modified polyester fiber is prepared by cutting polyester chips in a power density of 0.8-1.2W / cm 3It is prepared by conjugated deposition with zinc organic precursor in a vacuum plasma reactor, and the particle size of zinc oxide nanoparticles is ≤35nm.

[0033] It should also be noted that silicon carbide whiskers are produced by laser-induced vapor deposition of silicon carbide precursors in a high-gravity rotating bed, and the whisker aspect ratio is 35 to 50:1.

[0034] It should be noted that perfluoroalkylsilane is prepared by ultrasonically catalyzing the hydrosilylation of long-chain fluorocarbon compounds in a critical carbon dioxide fluid, and the fluorine content is ≥72 wt%.

[0035] It should also be noted that the zirconium phosphate silver ion-loaded powder is prepared by photochemically anchoring silver ions on a nano-zirconium phosphate carrier in a microchannel reactor, with a silver ion loading of 0.18 to 0.25 mmol / g.

[0036] It should also be noted that the cerium-based stabilized zirconia fiber is prepared by freeze-spinning zirconia sol in a static magnetic field with an intensity of 0.7 to 1.2 T, and the cerium doping amount is 5.0±0.3 mol%.

[0037] It should also be noted that the hydrophilic polyvinyl pyrrolidone polymer is prepared by free radical gradient polymerization of N-vinyl pyrrolidone in supercritical water, and the molecular weight distribution index is ≤1.15.

[0038] 2. Process:

[0039] Based on the above-mentioned nylon-based high-efficiency sewage treatment filter bag formula components, the present invention also proposes a method for preparing a nylon-based high-efficiency sewage treatment filter bag, comprising the following steps:

[0040] S1. 40 to 55 parts of high-strength nylon 6 fiber, 12 to 18 parts of polyvinylidene fluoride fiber, 8 to 15 parts of nano-zinc oxide-modified polyester fiber, and 5 to 10 parts of ultra-high molecular weight polyethylene fiber are fed into a twin-screw vortex blending machine; 0.3 to 1.5 parts of fumed silica are injected as a pore stabilizer under the protection of an inert gas with an argon purity of ≥99.999% and a flow rate of 15 L / min, and 0.5 to 3 parts of silicon carbide whiskers prepared by laser-induced vapor deposition are simultaneously added to enhance wear resistance; the fiber web is ejected from a slit melt-blown die head with a die lip gap of 0.18±0.02 mm and a drafting wind speed of 80 m / s, and is instantly shaped by a -30°C deep-cooled roller to form a dirt-holding layer-support layer composite base felt;

[0041] S2. Place 5 to 12 parts of polytetrafluoroethylene microporous film on a constant tension unwinder; use a target distance of 100 ± 5 mm, a sputtering power of 8 kW, and a vacuum of 5 × 10-3 P in a clean room at a temperature of 23 ± 0.5 ° C and a humidity of ≤ 30%. aThe magnetron sputtering spray equipment evenly deposits 0.1 to 0.8 parts of perfluoroalkylsilane synthesized from intercritical carbon dioxide fluid on the membrane surface to form a super-hydrophobic coating; the coating is then cross-linked and cured by electron beam irradiation.

[0042] S3. Dissolve 1.2 to 3 parts of supercritical water free radical polymerized polyvinyl pyrrolidone polymer in ultrapure water to form a 12 wt% solution, and inject it into the deep layer of the composite base felt obtained in step S1 through a high-pressure impregnation tank at a pressure of 3.5 ± 0.2 MPa and a temperature of 60 ° C; gradient dehydration in a synchrotron radiation drying oven, infrared wavelength 2.5 to 5 μm, energy flux density 1.2 kW / m 2 , so that the hydrophilic agent forms nano-scale water channels in the gaps between the fibers; 0.6 to 2 parts of microchannel photochemically anchored zirconium phosphate loaded silver ion powder are embedded into the base felt using an air flow carrying method with a carrier gas temperature of 150°C and a flow rate of 8m / s;

[0043] S4. Lay 2 to 6 parts of static magnetic field freeze-spun cerium-stabilized zirconia fibers and 3 to 8 parts of polyetheretherketone hot-melt bonding fibers on the bottom of the hot pressing mold, with a cerium doping amount of 5.0 ± 0.3 mol%; superimpose the functionalized base felt treated in step S3 and the film prepared in step S2, and feed it into a two-stage hot press:

[0044] First-stage hot pressing: temperature 310±5℃, pressure 12MPa, holding time 90 seconds, activate the polyetheretherketone bonding phase;

[0045] Secondary hot pressing: temperature 280±3℃, pressure 25MPa, time 120 seconds, to achieve zero-porosity composite;

[0046] Rapid cooling in liquid nitrogen quenching device at -196℃, cooling rate ≥150℃ / s;

[0047] S5. The composite filter material is wound onto a high-gravity rotating bed with a centrifugal factor of 350 ± 10 g and a rotation speed of 8500 rpm. Dynamic heat tension homogenization is performed by introducing 120°C saturated steam for 60 minutes to eliminate internal stress and improve dimensional stability. The composite filter material is then formed into filter bags using a laser cutting system with a wavelength of 1064 nm, a pulse energy of 50 mJ, and a cutting accuracy of ±0.01 mm.

[0048] It should be noted that the screw speed of the twin-screw vortex blending machine in step S1 is 220±10 rpm, and the temperature zones are set in four stages: 195°C, 210°C, 225°C, and 205°C.

[0049] Example 1: A nylon-based high-efficiency sewage treatment filter bag is prepared according to the following process:

[0050] Felt Forming: 50 parts high-strength nylon 6 fiber, 15 parts polyvinylidene fluoride fiber, 10 parts nano-zinc oxide-modified polyester fiber, and 6.5 parts ultra-high molecular weight polyethylene fiber were weighed and fed into a twin-screw vortex blender. Under argon gas with a purity of 99.999% and a flow rate of 15 L / min, 0.9 parts fumed silica was injected, and 1.8 parts silicon carbide whiskers (aspect ratio 43:1) were simultaneously added. The screw speed was 215 rpm, and the temperature range was four-stage: 195°C / 210°C / 225°C / 205°C. The mixture was ejected through a meltblown die with a lip gap of 0.18 mm at a wind speed of 80 m / s. The mixture was then shaped using a deep-cooled roller at -30°C.

[0051] S2. Film functionalization: 8.5 parts of polytetrafluoroethylene microporous film were fixed on a constant tension unwinder (0.5N / mm 2 ); In a clean room at 23°C and 28% humidity, a magnetron sputtering device (target distance 102mm, power 8kW, vacuum 5×10-3P a ) spraying 0.45 parts of perfluoroalkylsilane; electron beam irradiation crosslinking (energy 150KeV, dose rate 25kGy / min);

[0052] S3. Agent implantation: 2 parts of polyvinyl pyrrolidone polymer were dissolved in ultrapure water to form a 12% solution, and injected into the base felt through a high-pressure impregnation tank at a pressure of 3.5 MPa and a temperature of 60°C; infrared synchrotron radiation drying (wavelength 3.8 μm, energy flux density 1.2 kW / m 2 ) dehydration; embedding with 1.2 parts of zirconium phosphate-loaded silver ion powder at 150°C carrier gas (flow rate 8m / s);

[0053] S4 laminated composite: the bottom layer was laid with 4 parts of cerium-stabilized zirconia fiber (cerium doping amount 5.1 mol%) and 5.5 parts of polyetheretherketone fiber;

[0054] The treated base felt and film are stacked and hot pressed in two stages: the first stage: 310℃ / 12MPa / 90 seconds; the second stage: 282℃ / 25MPa / 120 seconds;

[0055] Liquid nitrogen rapid cooling (-196°C, cooling rate 160°C / s);

[0056] S5. Integration and shaping: The composite filter material is placed on a high-gravity rotating bed (centrifugal force 352g, rotation speed 8500rpm) and treated with saturated steam at 120°C for 60 minutes. The final filter bags are then cut by laser (wavelength 1064nm, pulse energy 50mJ, accuracy ±0.01mm).

[0057] Example 2: The nano zinc oxide modified polyester fiber is 15 parts, the polytetrafluoroethylene film is only 5 parts, and the rest is the same as Example 1;

[0058] Example 3: High strength nylon 6 fiber 55 parts, silicon carbide whisker 3 parts, others same as example 1;

[0059] Example 4: Cerium-based stabilized zirconia fiber 5 parts, polyether ether ketone fiber 6 parts, others same as example 1;

[0060] Example 5: Polyvinylidene fluoride fiber 14.2 parts, perfluoroalkyl silane 0.32 parts, others same as example 1;

[0061] Example parameters, see Table 1:

[0062] Table 1: Example material component parameter table

[0063]

[0064]

[0065] Comparative example 1: Polytetrafluoroethylene microporous film 3.5 parts, others same as example 1;

[0066] Comparative example 2: Polyvinylidene fluoride fiber 8.5 parts, others same as example 1;

[0067] Comparative example 3: Nano zinc oxide modified polyester fiber 20 parts, ultra-high molecular weight polyethylene fiber 0 parts, others same as example 1;

[0068] Comparative example 4: Silicon carbide whisker 0 parts, others same as example 1;

[0069] Comparative example 5: Perfluoroalkyl silane 0.02 parts, others same as example 1;

[0070] Comparative example parameters, see Table 2:

[0071] Table 2: Comparative example material component parameter table

[0072]

[0073]

[0074] III. Performance test:

[0075] a1. Sample preparation;

[0076] a2. According to the component allocation of Table 1 / Table 2;

[0077] a3. Perform the same S1-S5 process;

[0078] a4. Unified into a diameter of 150 mm, length of 500 mm filter sample;

[0079] Performance test:

[0080] b1. Flux decay rate: Circulate and filter simulated sewage containing suspended solids (200 mg / L) at 25°C. Record the initial flux (F0) at a pressure differential of 0.2 MPa and the flux after 24 hours of operation (F1). Calculate (1-F1 / F0) × 100%.

[0081] b2. Burst pressure: Test the filter bag burst limit pressure according to ISO13938;

[0082] b3 Chemical resistance: The filter bag was immersed in a 30% sodium hydroxide solution at 60 ° C for 72 hours and the tensile strength retention was measured;

[0083] b4. Wear times: Use ASTM D4886 standard grinding wheel wear tester (load 5N) to record the number of friction revolutions when the surface is damaged;

[0084] b5. Silver ion sustained release period: Use ICP-MS to detect the change in silver ion release concentration during continuous immersion for 30 days and calculate the effective antibacterial duration;

[0085] The performance data of the examples are shown in Table 3, and the performance data of the comparative examples are shown in Table 4:

[0086] Table 3: Comparison of performance data of examples

[0087] Performance indicators Example 1 Example 2 Example 3 Example 4 Example 5 Flux attenuation rate (%) 8.2 15.7 5.5 9.8 12.4 Burst pressure (MPa) 2.35 1.92 2.68 2.41 2.18 Alkali resistance strength retention rate (%) 94.6 89.3 96.2 93.1 90.8 Wear times (10,000 revolutions) 37.5 28.6 42.3 39.1 32.8 Silver ion sustained release cycle (days) >30 22 >30 >30 26

[0088] Table 4: Comparative Example Performance Data Comparison

[0089]

[0090]

[0091] 4. Data Analysis Conclusions:

[0092] According to Table 1 and Table 3, the rationality of the interval setting in the embodiments of the present invention can be seen. First, the flux attenuation rate of the embodiment is ≤15.7%, while that of the comparative example is ≥28.9%. This is due to the reasonable membrane-base ratio, i.e., 5-12 parts of polytetrafluoroethylene membrane to ensure surface filtration efficiency. The bursting pressure of the embodiment is >1.92 MPa, while that of the comparative example is ≤1.83 MPa, verifying the synergistic enhancement effect of nylon 6 ≥40 parts plus ultra-high molecular weight polyethylene ≥5 parts. At the same time, the sustained release of silver ions is >22 days, while that of the comparative example is ≤17 days, proving that the zirconium phosphate carrier can stably anchor silver ions in the range of 0.6-2 parts.

[0093] According to Tables 1 to 4, it can be seen that in Example 1, 8.5 parts of polytetrafluoroethylene membrane are combined with 50 parts of nylon matrix, and the flux attenuation rate is only 8.2%. In Example 2, the membrane is insufficient and rises to 15.7%, which is better than the high membrane amount Example 3 with 12 parts of membrane flux attenuation of 5.5%, but the cost increases by 40%; the combination of 1.8 parts of silicon carbide whiskers and 6.5 parts of ultra-high molecular polyethylene has a wear resistance of 375,000 revolutions, which is higher than the 328,000 revolutions of Example 5, and the bursting pressure of 2.35 MPa is better than the high whisker amount Example 3; 15 parts of polyvinylidene fluoride fiber (chemical resistance) plus 0.45 parts of perfluoroalkyl silane (hydrophobic layer) plus 4 parts of cerium-based zirconia fiber (thermal stability layer) has an alkali resistance strength retention rate of 94.6%. In Example 2, the flexibility of the matrix decreases due to the excessive amount of polyvinylidene fluoride to 18 parts, and the retention rate is only 89.3%. Therefore, Example 1 is regarded as the best embodiment of the present invention.

[0094] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0095] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A nylon-based high-efficiency sewage treatment filter bag, characterized in that: The invention is composed of the following raw materials in parts by weight: high-strength nylon 6 fiber: 40-55 parts; polytetrafluoroethylene microporous film: 5-12 parts; polyvinylidene fluoride fiber: 12-18 parts; nano zinc oxide modified polyester fiber: 8-15 parts; ultra-high molecular weight polyethylene fiber: 5-10 parts; silicon carbide whisker: 0.5-3 parts; perfluoroalkyl silane: 0.1-0.8 parts; hydrophilic polyvinyl pyrrolidone polymer: 1.2-3 parts; fumed silica: 0.3-1.5 parts; zirconium phosphate loaded silver ion powder: 0.6-2 parts; polyetheretherketone hot-melt bonding fiber: 3-8 parts; and cerium-based stabilized zirconia fiber: 2-6 parts.

2. A nylon-based high-efficiency sewage treatment filter bag according to claim 1, characterized in that: The polytetrafluoroethylene microporous film is prepared by subjecting a polytetrafluoroethylene dispersion to electric field-assisted phase separation in a deep-cold environment of -30°C to -15°C, and has a pore size uniformity of ±0.5 μm.

3. A nylon-based high-efficiency sewage treatment filter bag according to claim 2, characterized in that: The nano zinc oxide modified polyester fiber is prepared by heating polyester chips at a power density of 0.8 to 1.2 W / cm 3 It is prepared by conjugated deposition with zinc organic precursor in a vacuum plasma reactor, and the particle size of zinc oxide nanoparticles is ≤35nm.

4. A nylon-based high-efficiency sewage treatment filter bag according to claim 3, characterized in that: The silicon carbide whiskers are prepared by subjecting a silicon carbide precursor to laser-induced vapor deposition in a high-gravity rotating bed, and the whisker aspect ratio is 35-50:

1.

5. A nylon-based high-efficiency sewage treatment filter bag according to claim 4, characterized in that: The perfluoroalkylsilane is prepared by ultrasonically catalyzing the hydrosilylation of a long-chain fluorocarbon compound in a critical carbon dioxide fluid, and the fluorine content is ≥72 wt%.

6. A nylon-based high-efficiency sewage treatment filter bag according to claim 5, characterized in that: The zirconium phosphate silver ion-loaded powder is prepared by anchoring a nanometer zirconium phosphate carrier with photochemical silver ions in a microchannel reactor, and the silver ion loading amount is 0.18-0.25 mmol / g.

7. A nylon-based high-efficiency sewage treatment filter bag according to claim 6, characterized in that: The cerium-based stabilized zirconia fiber is prepared by freezing and directional spinning zirconia sol in a static magnetic field with an intensity of 0.7 to 1.2 T, and the cerium doping amount is 5.0±0.3 mol%.

8. A nylon-based high-efficiency sewage treatment filter bag according to claim 7, characterized in that: The hydrophilic polyvinyl pyrrolidone polymer is prepared by subjecting N-vinyl pyrrolidone to free radical gradient polymerization in supercritical water, and has a molecular weight distribution index of ≤1.

15.

9. The method for preparing a nylon-based high-efficiency sewage treatment filter bag according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. 40 to 55 parts of high-strength nylon 6 fiber, 12 to 18 parts of polyvinylidene fluoride fiber, 8 to 15 parts of nano-zinc oxide-modified polyester fiber, and 5 to 10 parts of ultra-high molecular weight polyethylene fiber are fed into a twin-screw vortex blending machine; 0.3 to 1.5 parts of fumed silica are injected as a pore stabilizer under the protection of an inert gas with an argon purity of ≥99.999% and a flow rate of 15 L / min, and 0.5 to 3 parts of silicon carbide whiskers prepared by laser-induced vapor deposition are simultaneously added to enhance wear resistance; the fiber web is ejected from a slit melt-blown die head with a die lip gap of 0.18±0.02 mm and a drafting wind speed of 80 m / s, and is instantly shaped by a -30°C deep-cooled roller to form a dirt-holding layer-support layer composite base felt; S2. Place 5 to 12 parts of polytetrafluoroethylene microporous film on a constant tension unwinder; use a target distance of 100 ± 5 mm, a sputtering power of 8 kW, and a vacuum of 5 × 10-3 P in a clean room at a temperature of 23 ± 0.5 ° C and a humidity of ≤ 30%. a The magnetron sputtering spray equipment evenly deposits 0.1 to 0.8 parts of perfluoroalkylsilane synthesized from intercritical carbon dioxide fluid on the membrane surface to form a superhydrophobic coating; Cross-linking and curing are completed by electron beam irradiation; S3. Dissolve 1.2 to 3 parts of supercritical water free radical polymerized polyvinyl pyrrolidone polymer in ultrapure water to form a 12 wt% solution, inject it into the deep layer of the composite base felt obtained in step 1 through a high-pressure impregnation tank at a pressure of 3.5 ± 0.2 MPa and a temperature of 60 ° C; gradient dehydration in a synchrotron radiation drying oven, infrared wavelength 2.5 to 5 μm, energy flux density 1.2 kW / m 2 , so that the hydrophilic agent forms nano-scale water channels in the gaps between the fibers; 0.6 to 2 parts of microchannel photochemically anchored zirconium phosphate loaded silver ion powder are embedded into the base felt using an air flow carrying method with a carrier gas temperature of 150°C and a flow rate of 8m / s; S4. Laying 2 to 6 parts of static magnetic field freeze-spun cerium-stabilized zirconia fibers and 3 to 8 parts of polyetheretherketone hot-melt bonding fibers on the bottom layer of the hot pressing mold, with a cerium doping amount of 5.0 ± 0.3 mol%; The functionalized base felt processed in step 3 and the film prepared in step 2 are stacked and sent into a two-stage hot press: First-stage hot pressing: temperature 310±5℃, pressure 12MPa, holding time 90 seconds, activate the polyetheretherketone bonding phase; Secondary hot pressing: temperature 280±3℃, pressure 25MPa, time 120 seconds, to achieve zero-porosity composite; Rapid cooling in liquid nitrogen quenching device at -196℃, cooling rate ≥150℃ / s; S5. The composite filter material is wound onto a high-gravity rotating bed with a centrifugal factor of 350 ± 10 g and a rotation speed of 8500 rpm. Dynamic heat tension homogenization is performed by introducing 120°C saturated steam for 60 minutes to eliminate internal stress and improve dimensional stability. The composite filter material is then formed into filter bags using a laser cutting system with a wavelength of 1064 nm, a pulse energy of 50 mJ, and a cutting accuracy of ±0.01 mm.

10. The method for preparing a nylon-based high-efficiency sewage treatment filter bag according to claim 9, characterized in that: In step S1, the screw speed of the twin-screw vortex blending machine is 220±10 rpm, and the temperature zones are set in four stages: 195° C., 210° C., 225° C., and 205° C.

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