High-temperature-resistant glass fiber composite folding filter cartridge and preparation method thereof

Abstract

The application provides a high-temperature-resistant glass fiber composite folding filter cartridge and a preparation method thereof, and comprises the following steps: alternately laying two layers of composite fiber webs and one layer of glass fiber mesh base cloth, performing composite needling on the formed sandwiched laminated body to obtain a composite needled felt, and performing hot pressing treatment on the composite needled felt to obtain a filter cartridge base material; wherein the composite fiber web is formed by mixed laying of bicomponent low-melting point polyester staple fiber, synthetic fiber and glass fiber; the filter cartridge base material is immersed in a flame retardant composite emulsion, and after drying, a high-temperature-resistant filter cartridge base material is obtained; wherein the flame retardant composite emulsion is prepared by mixing a composite flame retardant, a composite stiffening agent, an enhancing additive and water; and the surface of the high-temperature-resistant filter cartridge base material is sequentially coated and pleated to obtain the high-temperature-resistant glass fiber composite folding filter cartridge. The high-temperature-resistant glass fiber composite folding filter cartridge prepared in the scheme has excellent temperature resistance, erosion resistance, filtration performance and strength.

Description

Technical Field

[0001] This invention relates to the field of filter cartridge technology, and in particular to a high-temperature resistant glass fiber composite folded filter cartridge and its preparation method. Background Technology

[0002] In the field of industrial dust removal, pleated filter cartridges, with their large filtration area and high dust removal efficiency, are gradually replacing traditional filter bags as the mainstream filter element. However, the mainstream pleated membrane filter cartridges currently on the market, including polyester spunbond nonwoven filter media and polyester spunlace nonwoven filter media, all have obvious defects: The former is made by melting and spinning polymer chips into a web and then hot-rolling and reinforcing it. Although the processing is simple, the fibers have a planar interwoven structure, resulting in low stiffness (stiffness is usually <2000mg), requiring support from the skeleton. Moreover, its temperature resistance is only up to 110℃, and it is prone to softening and deformation above 120℃, making it unsuitable for high-temperature flue gas. The latter is formed by high-pressure hydroentangling, resulting in loose fiber entanglement and poor erosion resistance (3.5MPa high-pressure water gun rinsing time <2.5min). The membrane layer is prone to slippage and detachment due to fiber slippage, affecting its service life under high-temperature flue gas conditions. Both rely on the surface PTFE film to ensure filtration performance, and share common defects such as low erosion resistance and short service life. Furthermore, their temperature resistance is limited to below 120℃, making them unsuitable for high-temperature flue gas conditions of 180-230℃.

[0003] Furthermore, existing flame-retardant pleated filter cartridges often suffer from poor bonding between the flame retardant and the filter media matrix, and are prone to leakage at high temperatures. At the same time, it is difficult to balance high-temperature resistance with the stiffness required for pleated filter cartridges, resulting in wrinkles and insufficient stiffness after high-temperature setting, and poor stability of the pleated structure, which further limits their application scenarios and service life.

[0004] Therefore, there is an urgent need to provide a high-temperature resistant glass fiber composite folded filter cartridge and its preparation method. Summary of the Invention

[0005] This invention provides a high-temperature resistant glass fiber composite pleated filter cartridge and its preparation method, which can solve the problems of insufficient high-temperature resistance, poor bonding between flame retardant and filter material, and low strength of existing pleated filter cartridges.

[0006] In a first aspect, a method for preparing a high-temperature resistant glass fiber composite folded filter cartridge, the method comprising the following steps: (1) Two layers of composite fiber mesh and one layer of glass fiber mesh base fabric are laid alternately to form a sandwich laminate. The sandwich laminate is then composite needle-punched to obtain a composite needle-punched felt. The composite needle-punched felt is then hot-pressed to obtain a filter cartridge substrate. The composite fiber mesh is formed by a mixture of two-component low-melting-point polyester short fibers, synthetic fibers and glass fibers. (2) The filter cartridge substrate is immersed in a flame retardant composite emulsion and dried to obtain a high-temperature resistant filter cartridge substrate; wherein the flame retardant composite emulsion is prepared by mixing a composite flame retardant, a composite stiffener, a reinforcing agent and water. (3) The surface of the high-temperature resistant filter cartridge substrate is coated and pleated in sequence to obtain the high-temperature resistant glass fiber composite pleated filter cartridge.

[0007] Preferably, in step (1), the fineness of the bicomponent low-melting-point polyester staple fiber is 2~5D, the length is 38~64mm, and the melting point is 110~180℃; the synthetic fiber is at least one of aramid 1313 fiber, PPS fiber or polyimide fiber, and the length is preferably 38~51mm; the length of the glass fiber is 38~65mm.

[0008] Preferably, in step (1), by mass percentage, the composite fiber web contains 15-30% bicomponent low-melting-point polyester staple fiber, 10-20% synthetic fiber, and 50-70% glass fiber.

[0009] Preferably, in step (1), the basis weight of the fiberglass mesh is 120~420 g / m². 2 .

[0010] Preferably, in step (1), the acupuncture density of the composite acupuncture is 80~350 needles / cm. 2 The needle-punching depth is 3~15mm, and the basis weight of the composite needle-punched felt is 450~760g / m². 2 .

[0011] Preferably, in step (1), a three-roll calender is used to hot press the composite needle-punched felt; wherein the temperature of the upper roller is 50~150℃, the temperature of the middle roller is 110~220℃, and the pressure of the lower roller is 0.5~10MPa.

[0012] Preferably, in step (2), the composite flame retardant is obtained by mixing and compounding ammonium polyphosphate and melamine cyanurate.

[0013] More preferably, the mass ratio of ammonium polyphosphate to melamine cyanurate is (55~65):(35~45).

[0014] Preferably, the composite stiffening agent is obtained by mixing and compounding etherified modified melamine-formaldehyde resin and hydroxyl silicone oil.

[0015] More preferably, the mass ratio of etherified modified melamine-formaldehyde resin to hydroxyl silicone oil is (80~85):(15~20).

[0016] Preferably, the reinforcing agent is γ-aminopropyltriethoxysilane and bromotriazine.

[0017] More preferably, the mass ratio of γ-aminopropyltriethoxysilane to bromotriazine is (1~5):(2~5).

[0018] Preferably, in step (2), the flame retardant composite emulsion comprises, by mass percentage: 30-40% composite flame retardant, 30-40% composite stiffener, 3-10% reinforcing agent, and 25-35% water.

[0019] Preferably, in step (2), the filler weight of the filter cartridge substrate after impregnation with flame retardant composite emulsion is 105~120%.

[0020] More preferably, in step (2), the drying temperature is 180~230℃ and the time is 10~15min.

[0021] Preferably, in step (3), the coating material is a PTFE film with a pore size of 1~3μm, a porosity of 60%~90%, and a thickness of 2~15μm.

[0022] More preferably, in step (3), the temperature of the coating is 220~300℃ and the pressure is 1~3MPa.

[0023] Secondly, embodiments of the present invention also provide a high-temperature resistant glass fiber composite folded filter cartridge, which is prepared by the preparation method described in any one of the first aspects above.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects: In this invention, a composite fiber web is first formed by mixing and laying a web of bicomponent low-melting-point polyester staple fibers, synthetic fibers, and glass fibers. Then, two layers of the composite fiber web are alternately laid with a layer of glass fiber mesh substrate to form a sandwich-structured laminate. The laminate is then subjected to composite needle-punching reinforcement and hot-pressing treatment to obtain the filter cartridge substrate. During the hot-pressing process, the bicomponent low-melting-point polyester staple fibers melt, thereby bonding the glass fibers and synthetic fibers to form a stable three-dimensional interwoven structure. The three fiber components synergistically alleviate the brittleness of pure glass fibers, significantly improving the stiffness and erosion resistance of the filter material, and providing a smooth and stable substrate for subsequent membrane coating. Simultaneously, the glass fiber mesh substrate, as an intermediate reinforcing layer, can replace the metal mesh, improving the high-temperature resistance and mechanical strength of the filter material while reducing manufacturing costs. Subsequently, the filter cartridge substrate is immersed in a flame retardant composite emulsion prepared by mixing composite flame retardant, composite stiffener, reinforcing agent and water. After drying, the composite flame retardant is tightly bonded to the fibers in the filter cartridge substrate, and the stiffener is cross-linked and cured, thereby ensuring the stability and durability of the flame retardant at high temperatures and effectively avoiding the problem of easy loss of flame retardant in traditional impregnation methods. Finally, the synergistic effect of the three-dimensional interwoven structure of the fibers and the flame retardant stiffening system enables the composite folded filter cartridge to withstand the scouring time of a 3.5MPa high-pressure air gun for 4.0-4.5 minutes and can withstand high-temperature flue gas of 180-230℃ for a long time, solving the defects of traditional filter cartridges such as insufficient temperature resistance, low stiffness, need for metal support and easy peeling of the coating. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. 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.

[0026] As mentioned earlier, existing composite pleated filter cartridges suffer from insufficient high-temperature resistance. To meet high-temperature filtration requirements, some pleated filter cartridges are made using pure glass fiber filter media. While glass fiber has excellent high-temperature resistance, it is brittle, prone to breakage, and difficult to control in terms of stiffness. Most require the addition of metal mesh support, which not only increases manufacturing costs and process complexity but also makes filter cartridge recycling difficult and prone to secondary pollution. In addition, some technologies have attempted to combine bicomponent low-melting-point polyester staple fiber with ordinary polyester to make filter cartridges. Although this method can improve the stiffness of the filter media, its temperature resistance limit is only 150℃. The low melting point of bicomponent low-melting-point polyester staple fiber will cause the filter media to melt and deform under operating conditions above 180℃, resulting in the collapse of the filtration structure and making it unsuitable for medium- and high-temperature dust removal scenarios.

[0027] To address one or more of the aforementioned problems, embodiments of the present invention provide a method for preparing a high-temperature resistant glass fiber composite folded filter cartridge, the method comprising the following steps: (1) Two layers of composite fiber mesh and one layer of glass fiber mesh base fabric are laid alternately to form a sandwich laminate, and the sandwich laminate is composite needle punched to obtain a composite needle punch felt. The composite needle punch felt is then hot-pressed to obtain a filter cartridge substrate; wherein, the composite fiber mesh is formed by a mixture of two-component low-melting-point polyester short fibers, synthetic fibers and glass fibers. (2) The filter cartridge substrate is immersed in a flame retardant composite emulsion and dried to obtain a high-temperature resistant filter cartridge substrate; wherein the flame retardant composite emulsion is prepared by mixing a composite flame retardant, a composite stiffener, a reinforcing agent and water. (3) The surface of the high-temperature resistant filter cartridge substrate is coated and pleated in sequence to obtain the high-temperature resistant glass fiber composite pleated filter cartridge.

[0028] In this embodiment of the invention, firstly, a composite fiber web is formed by mixing and laying a web of bicomponent low-melting-point polyester staple fibers, synthetic fibers, and glass fibers. Then, two layers of composite fiber web are alternately laid with a layer of glass fiber mesh base fabric to form a sandwich structure laminate. The laminate is then subjected to composite needle punching reinforcement and hot pressing treatment to obtain the filter cartridge substrate. During the hot pressing process, the bicomponent low-melting-point polyester staple fibers melt, thereby bonding the glass fibers and synthetic fibers to form a stable three-dimensional interwoven structure. The three fiber components work synergistically to alleviate the brittleness problem of pure glass fiber, significantly improving the stiffness and erosion resistance of the filter material, and providing a flat and stable substrate for subsequent membrane coating. At the same time, the glass fiber mesh base fabric, as an intermediate reinforcing layer, can replace the metal mesh, improving the high temperature resistance and mechanical strength of the filter material while reducing the manufacturing cost.

[0029] Subsequently, the filter cartridge substrate is immersed in a flame retardant composite emulsion prepared by mixing composite flame retardant, composite stiffener, reinforcing agent and water. After drying, the composite flame retardant is tightly bonded to the fibers in the filter cartridge substrate, and the stiffener is cross-linked and cured, thereby ensuring the stability and durability of the flame retardant at high temperatures and effectively avoiding the problem of easy loss of flame retardant in traditional impregnation methods. Finally, the synergistic effect of the three-dimensional interwoven structure of the fibers and the flame retardant stiffening system enables the composite folded filter cartridge to withstand the scouring time of a 3.5MPa high-pressure air gun for 4.0-4.5 minutes and can withstand high-temperature flue gas of 180-230℃ for a long time, solving the defects of traditional filter cartridges such as insufficient temperature resistance, low stiffness, need for metal support and easy peeling of the coating.

[0030] According to some preferred embodiments, in step (1), the fineness of the bicomponent low-melting-point polyester staple fiber is 2~5D (e.g., it can be 2D, 3D, 4D or 5D), the length is 38~64mm (e.g., it can be 38mm, 40mm, 45mm, 50mm, 55mm, 60mm or 64mm), and the melting point is 110~180℃ (e.g., it can be 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃ or 180℃); the synthetic fiber is at least one of aramid 1313 fiber, PPS fiber or polyimide fiber, and the length is preferably 38~51mm (e.g., it can be 38mm, 40mm, 45mm, 50mm or 51mm); the length of the glass fiber is 38~65mm (e.g., it can be 38mm, 40mm, 45mm, 50mm, 55mm, 60mm or 65mm).

[0031] In this embodiment of the invention, bicomponent low-melting-point polyester staple fibers are mixed with synthetic fibers and glass fibers in a certain proportion. After opening, carding, and cross-laying, a composite fiber web is formed. The aforementioned synthetic fibers possess excellent high-temperature resistance and good mechanical strength. When mixed with glass fibers, they not only complement the high-temperature resistance of glass fibers but also enhance the entanglement force with glass fibers, effectively improving the brittleness of pure glass fibers and enhancing overall toughness. Meanwhile, the bicomponent low-melting-point polyester staple fibers can melt during hot pressing, thus acting as a bonding medium to firmly interweave the synthetic fibers and glass fibers, forming a stable and uniform three-dimensional network structure. This structure not only greatly improves the stiffness and dimensional stability of the filter material, making it less prone to softening or deformation at high temperatures, but also provides a flat and stable substrate for subsequent membrane coating. The synergistic effect of the three fibers helps ensure good high-temperature resistance, erosion resistance, and high stiffness of the filter material.

[0032] According to some preferred embodiments, in step (1), the composite fiber web contains, by mass percentage, 15-30% bicomponent low-melting-point polyester staple fiber (e.g., 15%, 20%, 25% or 30%), 10-20% synthetic fiber (e.g., 10%, 12%, 15%, 18% or 20%), and 50-70% glass fiber (e.g., 50%, 55%, 60%, 65% or 70%).

[0033] Experiments of this invention have confirmed that by precisely controlling the ratio of the three fibers, an optimal balance between performance and cost can be achieved, enabling the filter material to operate stably for a long period in high-temperature flue gas at 180–230℃, while maintaining high stiffness, excellent erosion resistance, and economy. If the content of the bicomponent low-melting-point polyester staple fiber is too low, it will lead to insufficient fusion bonding between fibers, resulting in insufficient strength of the formed three-dimensional structure, making it difficult to guarantee the stiffness and overall stability of the filter material. If its content is too high, it will introduce too many low-temperature components, thereby reducing the temperature resistance of the filter material. Glass fiber and synthetic fiber are the main components for high-temperature resistance and reinforcement. If the content of synthetic fiber is too low, the content of glass fiber will be relatively high, resulting in greater brittleness of the filter material and easy fiber breakage. If its content is too high, although it can further improve the temperature resistance, it will significantly increase the cost. At the same time, if the content of glass fiber is too low, it will affect the dimensional stability of the filter material at high temperatures.

[0034] According to some preferred embodiments, in step (1), the basis weight of the fiberglass mesh is 120~420 g / m². 2 (For example, it can be 120 g / m 2 150 g / m 2 200 g / m 2 250 g / m 2 300 g / m2 400 g / m 2 Or 420 g / m 2 The acupuncture density of the composite acupuncture is 80~350 needles / cm. 2 (For example, it can be 80 stitches / cm) 2 100 stitches / cm 2 150 stitches / cm 2 200 stitches / cm 2 250 stitches / cm 2 300 stitches / cm 2 Or 350 stitches / cm 2 The needle-punching depth is 3~15mm, and the basis weight of the composite needle-punched felt is 450~760g / m². 2 (For example, it can be 450 g / m 2 500 g / m 2 500 g / m 2 600 g / m 2 650 g / m 2 700 g / m 2 Or 760g / m 2 ).

[0035] In this embodiment of the invention, a sandwich structure is constructed by arranging a glass fiber mesh of a certain weight between two layers of composite fiber mesh as an intermediate support layer. The laminate is then reinforced by composite needle punching. By precisely controlling process parameters such as needle punching depth and needle punching density, the composite fiber mesh and glass fiber mesh of the upper and lower layers are fully entangled and fixed, so that the three layers of materials form a through-hole three-dimensional interlocking reinforcement structure, which is conducive to preparing an integrated composite needle punched felt with strong interlayer bonding.

[0036] According to some preferred embodiments, in step (1), a three-roll calender is used to hot-press the composite needle-punched felt; wherein, the temperature of the upper roller is 50~150℃ (for example, it can be 50℃, 80℃, 100℃, 120℃ or 150℃), the temperature of the middle roller is 110~220℃ (for example, it can be 110℃, 130℃, 150℃, 180℃, 200℃ or 220℃), and the pressure of the lower roller is 0.5~10MPa (for example, it can be 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 5 MPa, 8 MPa or 10 MPa).

[0037] In this embodiment of the invention, the composite needle-punched felt is hot-pressed and shaped using a three-roll calender. By controlling the hot-pressing temperature of the upper and middle rolls and the pressure of the lower roll, not only can the bicomponent low-melting-point polyester staple fibers be melted and uniformly bonded to the surrounding glass fibers and synthetic fibers to form a three-dimensional interwoven network, but the fiber ends can also be effectively fixed, surface fuzz reduced, and the thermal shrinkage rate of the substrate significantly reduced during subsequent high-temperature use.

[0038] According to some preferred embodiments, in step (2), the composite flame retardant is obtained by mixing and compounding ammonium polyphosphate and melamine cyanurate; preferably, the mass ratio of ammonium polyphosphate to melamine cyanurate is (55~65):(35~45) (for example, it can be 55:45, 60:40, or 65:45); the composite stiffening agent is obtained by mixing and compounding etherified modified melamine formaldehyde resin and hydroxyl silicone oil; preferably, the mass ratio of etherified modified melamine formaldehyde resin to hydroxyl silicone oil is (80~85). The ratio of γ-aminopropyltriethoxysilane to bromotriazine is (1-5):(2-5) (e.g., 1:2, 1:3, 1:5, 2:2, 2:4, 2:5, 3:2, 3:5, 4:2, 4:5, 5:2, 5:3, 5:4 or 5:5). The reinforcing agent is γ-aminopropyltriethoxysilane and bromotriazine, preferably, the mass ratio of γ-aminopropyltriethoxysilane to bromotriazine is (1-5):(2-5) (e.g., 1:2, 1:3, 1:5, 2:2, 2:4, 2:5, 3:2, 3:5, 4:2, 4:5, 5:2, 5:3, 5:4 or 5:5).

[0039] In this embodiment of the invention, a composite flame retardant is formed by mixing ammonium polyphosphate and melamine cyanurate, and brominated triazine is introduced as a synergistic enhancer, forming a multi-layered flame retardant protection system that compensates for the insufficient temperature resistance of the two-component low-melting-point polyester component at high temperatures. Furthermore, a composite stiffening agent is formed by etherified modified melamine-formaldehyde resin and hydroxyl silicone oil, which work synergistically to further improve the stiffness of the filter material. At the same time, a certain proportion of γ-aminopropyltriethoxysilane is added as a reinforcing agent, which can enhance the interfacial bonding between the fiber and the flame retardant coating through chemical bonding, preventing the flame retardant from being lost at high temperatures.

[0040] According to some preferred embodiments, in step (2), the flame retardant composite emulsion comprises, by mass percentage: 30-40% composite flame retardant (e.g., 30%, 32%, 35%, 38%, or 40%), 30-40% composite stiffener (e.g., 30%, 32%, 35%, 38%, or 40%), 3-10% reinforcing agent (e.g., 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%), and 25-35% water (e.g., 25%, 28%, 30%, 32%, or 35%).

[0041] In this embodiment of the invention, by synergistically controlling the proportions of composite flame retardant, composite stiffener, and reinforcing agent in the flame retardant composite emulsion, it is beneficial to maintain the good impregnation performance of the composite emulsion while ensuring that the filter material has excellent flame retardancy, high stiffness, and strong interfacial bonding. If the content of composite flame retardant is too low, it will not be conducive to forming a complete and effective flame retardant barrier on the fiber surface, resulting in a decrease in the flame retardant performance of the filter material. If its content is too high, although it can improve the flame retardant effect, it will not only affect the filtration performance of the filter material, but also increase the raw material cost. At the same time, if the content of stiffener is too low, it will not be enough to significantly enhance the stiffness of the filter material, while if its content is too high, it may cause the filter material to become brittle. Furthermore, if the content of reinforcing agent is too low, it will not be conducive to ensuring a good interfacial bonding force between the fiber and the flame retardant coating.

[0042] According to some preferred embodiments, in step (2), the filler weight of the filter cartridge substrate after impregnation with flame retardant composite emulsion is 105~120% (e.g., 105%, 108%, 110%, 112%, 115%, 118% or 120%); the drying temperature is 180~230℃ (e.g., 180℃, 190℃, 200℃, 210℃, 220℃ or 230℃), and the time is 10~15min (e.g., 10min, 12min or 15min).

[0043] In this embodiment of the invention, the flame retardant composite emulsion formed by the above components is uniformly loaded onto the fiber surface of the filter cartridge substrate through an impregnation process. By controlling the amount of residue during the impregnation process, it is beneficial to ensure the effective loading of the above functional components while ensuring good filtration performance. After drying and curing, the components in the composite emulsion are firmly bonded to the fibers, thereby forming a coating on the fiber surface that has both excellent flame retardant and reinforcing effects.

[0044] According to some preferred embodiments, in step (3), the material of the coating is a PTFE film, the pore size of the PTFE film is 1~3μm (for example, it can be 1μm, 2μm or 3μm), the porosity is 60%~90% (for example, it can be 60%, 70%, 80% or 90%), the thickness is 2~15μm (for example, it can be 2μm, 5μm, 8μm, 10μm or 15μm), and the air permeability is 5~20cm / s@127Pa; the temperature of the coating is 220~300℃ (for example, it can be 220℃, 250℃, 280℃ or 300℃), and the pressure is 1~3MPa (for example, it can be 1 MPa, 2 MPa or 3 MPa).

[0045] In this embodiment of the invention, based on the above-mentioned flame retardant composite emulsion impregnation, the PTFE film is further bonded to the high-temperature resistant filter cartridge substrate using high-temperature hot pressing. This significantly enhances the bonding force between the film and the filter cartridge substrate, achieving a film peel strength of ≥15N / 25mm, far exceeding that of traditional coating processes. This effectively suppresses the risk of film detachment and substrate softening at high temperatures, ensuring the coating stability and filtration accuracy of the filter material under long-term high-temperature conditions of 180-230℃. Simultaneously, it ensures the long-term stability of the filter material's rigidity, flame retardancy, and filtration performance, thereby comprehensively improving the service reliability and lifespan of the filter cartridge.

[0046] It should be noted that after hot pressing and coating, the process also includes pleating the membrane according to the specifications of pleat depth 20-28mm and pleat number 30-45, welding fiberglass reinforcing straps along the width direction, and installing metal end caps at both ends, finally producing a high-temperature resistant fiberglass composite pleated filter cartridge.

[0047] This invention also provides a high-temperature resistant glass fiber composite folded filter cartridge, which is prepared using any of the above-described preparation methods.

[0048] In summary, the high-temperature resistant glass fiber composite folded filter cartridge prepared using the above method possesses excellent temperature resistance, erosion resistance, filtration performance, and strength. Experiments have confirmed that it can withstand high-temperature flue gas of 180-230℃ for extended periods, far exceeding the upper temperature limit of traditional polyester filter cartridges (<120℃). Furthermore, the filter material's stiffness reaches 2100-2400mg, which is 1.2-1.3 times that of traditional spunbond filter materials. It maintains the stability of its folded structure without the need for metal mesh support, significantly reducing costs compared to pure glass fiber plus metal mesh products. Simultaneously, the filter material can be eroded for 4.0-4.5 minutes under a 3.5MPa high-pressure air gun (compared to only 2.3 minutes for traditional spunlace filter materials), and the PTFE film is firmly bonded to the substrate with a peel strength ≥15N / 25mm (compared to <5N / 25mm for traditional membrane filter materials). No membrane detachment or wrinkling occurs at high temperatures. This filter cartridge is suitable for high-temperature flue gas dust removal scenarios of 180~230℃ in industries such as power, metallurgy, and chemical processing, breaking through the scenario limitations of traditional filter cartridges.

[0049] To more clearly illustrate the technical solution and advantages of the present invention, the following describes in detail a high-temperature resistant glass fiber composite folded filter cartridge and its preparation method through several embodiments.

[0050] Example 1:

[0051] (1) By weight ratio, 15% of bicomponent low melting point polyester staple fiber (fineness 2D, length 38mm, melting point 110℃), 10% of synthetic fiber (aramid 1313 fiber, fineness 1.5D, length 38mm), and 75% of alkali-free glass fiber (count 80s, length 51mm) are mixed and then opened, carded and cross-laid to form a composite fiber web; Two layers of composite fiber mesh are bonded to a single layer of fiberglass mesh base fabric (120g / m²). 2 Alternately lay the layers to form a sandwich structure, at a stitch density of 80 stitches / cm. 2 The sandwich-like laminate was subjected to composite needling at a needle density and a needle depth of 3-6 mm to obtain a yield of 450 g / m³. 2 The composite needle-punched felt was hot-pressed using a three-roll calender (upper roll temperature 50℃, middle roll temperature 110℃, lower roll pressure 0.5MPa) to obtain the filter cartridge substrate. (2) By weight ratio, 30% of composite flame retardant (ammonium polyphosphate and melamine cyanurate in a mass ratio of 55:45), 30% of composite stiffener (etherified melamine formaldehyde resin and hydroxyl silicone oil in a mass ratio of 80:20), 30% of deionized water, and 10% of reinforcing agent (γ-aminopropyltriethoxysilane and bromotriazine in a mass ratio of 5:5) are stirred and mixed to obtain a flame retardant composite emulsion; The filter cartridge substrate is immersed in the above-mentioned flame retardant composite emulsion, and the roll-out weight of the substrate after immersion is controlled to be 105%. After drying at 180°C, a high-temperature resistant filter cartridge substrate is obtained. (3) First, a PTFE film (porosity 60%, thickness 2μm, air permeability 5cm / s@127Pa) is covered on the surface of the high temperature resistant filter cartridge substrate. Then, it is hot-pressed at 300℃ and 1MPa. After that, pleats are made with a pleat depth of 20mm and a pleat number of 30. After welding the straps and installing the metal end caps, a high temperature resistant glass fiber composite folded filter cartridge is obtained.

[0052] In this embodiment, the filter cartridge has a temperature resistance of 230℃ (90% stiffness retention rate after 500h aging), a stiffness of 2168mg, a 3.5MPa scouring time of 4.0min, a PTFE film peel strength of 15N / 25mm, and a filtration efficiency of 99.5%.

[0053] Example 2:

[0054] (1) By weight ratio, 30% of bicomponent low melting point polyester staple fiber (fineness 5D, length 64mm, melting point 180℃), 20% of synthetic fiber (PPS fiber, fineness 2D, length 51mm), and 50% of alkali-free glass fiber (count 80s, length 60mm) are mixed and then opened, carded and cross-laid to form a composite fiber web; Two layers of composite fiber mesh are bonded to a single layer of fiberglass mesh base fabric (380g / m²). 2 Alternately lay the layers to form a sandwich structure, at a density of 200 stitches / cm. 2 The sandwich-like laminate was subjected to composite needle punching at a needle punching density and a needle punching depth of 10-15 mm to obtain a yield of 760 g / m³. 2 The composite needle-punched felt was hot-pressed using a three-roll calender (upper roll temperature 150℃, middle roll temperature 180℃, lower roll pressure 1MPa) to obtain the filter cartridge substrate. (2) By weight ratio, 40% of composite flame retardant (ammonium polyphosphate and melamine cyanurate in a mass ratio of 65:35), 30% of composite stiffener (etherified melamine formaldehyde resin and hydroxyl silicone oil in a mass ratio of 85:15), 25% of deionized water, and 5% of reinforcing agent (γ-aminopropyltriethoxysilane and bromotriazine in a mass ratio of 1:4) are stirred and mixed to obtain a flame retardant composite emulsion; The filter cartridge substrate is immersed in the above-mentioned flame retardant composite emulsion, and the roll-out weight of the substrate after immersion is controlled to be 120%. After drying at 220°C, a high-temperature resistant filter cartridge substrate is obtained. (3) First, a PTFE film (porosity 90%, thickness 15μm, air permeability 20cm / s@127Pa) is covered on the surface of the high temperature resistant filter cartridge substrate. Then, it is hot-pressed at 250℃ and 3MPa. After that, pleats are made with a pleat depth of 28mm and a pleat number of 45. After welding the straps and installing the metal end caps, a high temperature resistant glass fiber composite pleated filter cartridge is obtained.

[0055] The filter cartridge in this embodiment has a temperature resistance of up to 180℃ (88% stiffness retention rate after 500h aging), a stiffness of 2350mg, withstands 3.5MPa scouring for 4.5min, a PTFE peel strength of 18N / 25mm, and a filtration efficiency of 99.7%. Example 3:

[0056] (1) By weight ratio, 20% of bicomponent low melting point polyester staple fiber (fineness 3D, length 51mm, melting point 150℃), 15% of synthetic fiber (polyimide fiber, fineness 1.5D, length 45mm), and 65% of alkali-free glass fiber (count 80s, length 65mm) are mixed and then opened, carded and cross-laid to form a composite fiber web; Two layers of composite fiber mesh are bonded to a single layer of fiberglass mesh base fabric (200g / m²). 2 Alternately lay the layers to form a sandwich structure, at a stitch density of 120 stitches / cm. 2 The sandwich-like laminate was subjected to composite needling at a needling density and a needling depth of 8-12 mm to obtain a yield of 600 g / m³. 2The composite needle-punched felt was hot-pressed using a three-roll calender (upper roll temperature 100℃, middle roll temperature 150℃, lower roll pressure 2.5MPa) to obtain the filter cartridge substrate. (2) By weight ratio, 35% of composite flame retardant (ammonium polyphosphate and melamine cyanurate in a mass ratio of 60:40), 35% of composite stiffener (etherified melamine formaldehyde resin and hydroxyl silicone oil in a mass ratio of 82:18), 23% of deionized water, and 7% of reinforcing agent (γ-aminopropyltriethoxysilane and bromotriazine in a mass ratio of 2:5) are stirred and mixed to obtain a flame retardant composite emulsion; The filter cartridge substrate is immersed in the above-mentioned flame retardant composite emulsion, and the roll-out weight of the substrate after immersion is controlled to be 115%. After drying at 190°C, a high-temperature resistant filter cartridge substrate is obtained. (3) First, a PTFE film (porosity 75%, thickness 8μm, air permeability 12cm / s@127Pa) is covered on the surface of the high temperature resistant filter cartridge substrate. Then, it is hot-pressed at 270℃ and 2MPa. After that, pleats are made with a pleat depth of 25mm and a pleat number of 38. After welding the straps and installing the metal end caps, a high temperature resistant glass fiber composite folded filter cartridge is obtained.

[0057] The filter cartridge in this embodiment has a temperature resistance of 210℃ (89% stiffness retention rate after 500h aging), a stiffness of 2198mg, can withstand 3.5MPa scouring for 4.3min, has a PTFE peel strength of 15.5N / 25mm, and a filtration efficiency of 99.6%.

[0058] Example 4:

[0059] (1) By weight ratio, 25% of bicomponent low melting point polyester staple fiber (fineness 4D, length 55mm, melting point 160℃), 10% of synthetic fiber (1:1 aramid / PPS blended fiber, fineness 2D, length 45mm), and 65% of alkali-free glass fiber (count 80s, length 55mm) are mixed and then opened, carded and cross-laid to form a composite fiber web; Two layers of composite fiber mesh are bonded to a single layer of fiberglass mesh base fabric (280g / m²). 2 Alternately lay the layers to form a sandwich structure, at a stitch density of 180 stitches / cm. 2 The sandwich-like laminate was subjected to composite needling at a needle density and a needle depth of 6-10 mm to obtain a yield of 700 g / m³. 2 The composite needle-punched felt was hot-pressed using a three-roll calender (upper roll temperature 120℃, middle roll temperature 160℃, lower roll pressure 5MPa) to obtain the filter cartridge substrate. (2) By weight ratio, 32% of composite flame retardant (ammonium polyphosphate and melamine cyanurate in a mass ratio of 58:42), 32% of composite stiffener (etherified melamine formaldehyde resin and hydroxyl silicone oil in a mass ratio of 81:19), 30% of deionized water, and 6% of reinforcing agent (γ-aminopropyltriethoxysilane and bromotriazine in a mass ratio of 3:3) are stirred and mixed to obtain a flame retardant composite emulsion; The filter cartridge substrate is immersed in the above-mentioned flame retardant composite emulsion, and the roll-out weight of the substrate after immersion is controlled to be 110%. After drying at 200°C, a high-temperature resistant filter cartridge substrate is obtained. (3) First, a PTFE film (porosity 80%, thickness 10μm, air permeability 15cm / s@127Pa) is covered on the surface of the high temperature resistant filter cartridge substrate. Then, it is hot-pressed at 280℃ and 2.5MPa. After that, pleats are made with a pleat depth of 24mm and a pleat number of 40. After welding the straps and installing the metal end caps, a high temperature resistant glass fiber composite pleated filter cartridge is obtained.

[0060] The filter cartridge in this embodiment has a temperature resistance of 220℃ (87% stiffness retention rate after 500h aging), a stiffness of 2250mg, can withstand 3.5MPa scouring for 4.4min, a PTFE peel strength of 17.8N / 25mm, and a filtration efficiency of 99.65%.

[0061] Example 5:

[0062] (1) By weight ratio, 18% of bicomponent low melting point polyester staple fiber (fineness 2.5D, length 45mm, melting point 120℃), 12% of synthetic fiber (polyimide fiber, fineness 1.5D, length 40mm), and 70% of alkali-free glass fiber (count 80s, length 60mm) are mixed and then opened, carded and cross-laid to form a composite fiber web; Two layers of composite fiber mesh are bonded to a single layer of fiberglass mesh base fabric (320g / m²). 2 Alternately lay the layers to form a sandwich structure, at a density of 250 stitches / cm. 2 The sandwich-like laminate was subjected to composite needling at a needle density and a needle depth of 5-8 mm to obtain a yield of 750 g / m³. 2 The composite needle-punched felt was hot-pressed using a three-roll calender (upper roll temperature 80℃, middle roll temperature 130℃, lower roll pressure 3MPa) to obtain the filter cartridge substrate. (2) By weight ratio, 38% of composite flame retardant (ammonium polyphosphate and melamine cyanurate in a mass ratio of 62:38), 30% of composite stiffener (etherified melamine-formaldehyde resin and hydroxyl silicone oil in a mass ratio of 83:17), 26% of deionized water, and 6% of reinforcing agent (γ-aminopropyltriethoxysilane and bromotriazine in a mass ratio of 2:4) are stirred and mixed to obtain a flame retardant composite emulsion; The filter cartridge substrate is immersed in the above-mentioned flame retardant composite emulsion, and the roll-out weight of the substrate after immersion is controlled to be 108%. After drying at 210°C, a high-temperature resistant filter cartridge substrate is obtained. (3) First, a PTFE film (porosity 70%, thickness 6μm, air permeability 8cm / s@127Pa) is covered on the surface of the high temperature resistant filter cartridge substrate. Then, it is hot-pressed at 250℃ and 1.5MPa. After that, pleats are made with a pleat depth of 22mm and a pleat number of 35. After welding the binding strap and installing the metal end cap, a high temperature resistant glass fiber composite folded filter cartridge is obtained.

[0063] The filter cartridge in this embodiment has a temperature resistance of 225℃ (89% stiffness retention rate after 500h aging), a stiffness of 2180mg, can withstand 3.5MPa scouring for 4.2min, a PTFE peel strength of 15.2N / 25mm, and a filtration efficiency of 99.58%.

[0064] Example 6:

[0065] Example 6 is basically the same as Example 1, except that in step (1), 30% of bicomponent low melting point polyester staple fiber (fineness 2D, length 38mm, melting point 110℃), 30% of synthetic fiber (aramid 1313 fiber, fineness 1.5D, length 38mm) and 40% of alkali-free glass fiber (count 80s, length 51mm) are mixed by weight ratio, and a composite fiber web is formed after opening, carding and cross-laying.

[0066] The filter cartridge in this embodiment has a temperature resistance of 225℃ (80% stiffness retention rate after 500h aging), a stiffness of 2320mg, can withstand 3.5MPa scouring for 4.4min, a PTFE peel strength of 17.2N / 25mm, and a filtration efficiency of 99.60%.

[0067] Example 7:

[0068] Example 7 is basically the same as Example 1, except that in step (2), 45% of the composite flame retardant (ammonium polyphosphate and melamine cyanurate in a mass ratio of 55:45), 20% of the composite stiffener (etherified melamine formaldehyde resin and hydroxyl silicone oil in a mass ratio of 80:20), 30% of deionized water, and 5% of the reinforcing agent (γ-aminopropyltriethoxysilane and bromotriazine in a mass ratio of 2:3) are stirred and mixed to obtain the flame retardant composite emulsion.

[0069] The filter cartridge in this embodiment has a temperature resistance of 225℃ (82% stiffness retention rate after 500h aging), a stiffness of 1980mg, can withstand 3.5MPa scouring for 4.1min, has a PTFE peel strength of 15.2N / 25mm, and a filtration efficiency of 99.56%.

[0070] Example 8:

[0071] Example 8 is basically the same as Example 1, except that: by weight ratio, 25% of the composite flame retardant (ammonium polyphosphate and melamine cyanurate in a mass ratio of 55:45), 30% of the composite stiffener (etherified melamine-formaldehyde resin and hydroxyl silicone oil in a mass ratio of 80:20), 30% of deionized water, and 15% of the reinforcing agent (γ-aminopropyltriethoxysilane and bromotriazine in a mass ratio of 1:2) are stirred and mixed to obtain a flame retardant composite emulsion.

[0072] The filter cartridge in this embodiment has a temperature resistance of 225℃ (85% stiffness retention rate after 500h aging), a stiffness of 2150mg, can withstand 3.5MPa scouring for 4.0min, a PTFE peel strength of 15.3N / 25mm, and a filtration efficiency of 99.52%.

[0073] Comparative Example 1 (1) Using conventional 300g / m 2 Polyester spunbond substrate is used as the filter cartridge substrate; (2) After covering the surface of the filter cartridge substrate with a PTFE film (porosity 65%, thickness 2.5μm, air permeability 5.5cm / s@127Pa), hot-press composite at 220℃ and 1MPa, then pleat it with a pleat depth of 20mm and a pleat number of 32, weld the binding strap and install the metal end cap to obtain the glass fiber composite pleated filter cartridge.

[0074] In this comparative example, the filter cartridge has a temperature resistance of 110℃ (it softens and deforms after 2 hours at 180℃), a stiffness of 1659mg, a 3.5MPa scouring time of 2.3min, a PTFE membrane peel strength of 4N / 25mm, a filtration efficiency of 99.1%, and cannot be used under 180℃ conditions.

[0075] Comparative Example 2 (1) Alkali-free glass fiber (80s count, 51mm length) was opened, combed and needle-punched, and a metal mesh was embedded for support during the needle-punching process to obtain 600g / m 2 Pure glass fiber filter cartridge substrate; (2) After covering the surface of the filter cartridge substrate with a PTFE film (porosity 82%, thickness 9.8μm, air permeability 15.2cm / s@127Pa), it is hot-pressed at 300℃ and 2.5MPa. Then, pleats are made with a pleat depth of 24mm and a pleat number of 40. After welding the binding straps and installing the metal end caps, a glass fiber composite pleated filter cartridge is obtained.

[0076] In this comparative example, the filter cartridge has a temperature resistance of 230℃ (80% stiffness retention rate after 500h aging) and a stiffness of 1902mg. However, the fiber is brittle and easily breaks. It can withstand 3.5MPa scouring for 3.0min. The PTFE film peel strength is 8N / 25mm. Furthermore, the metal mesh makes recycling difficult, and the cost is 40% higher than that of Example 4.

[0077] Comparative Example 3 Comparative Example 3 is basically the same as Example 3, except that in step (1), two layers of composite fiber web are bonded to a layer of polyester filament base fabric (200g / m²). 2 Alternately lay the layers at a rate of 120 stitches / cm. 2 The sandwich-like laminate was subjected to composite needling at a needling density and a needling depth of 8-12 mm to obtain a yield of 605 g / m³. 2 The composite needle-punched felt was hot-pressed using a three-roll calender (upper roll temperature 100℃, middle roll temperature 150℃, lower roll pressure 2.5MPa) to obtain the filter cartridge substrate.

[0078] In this comparative example, the filter cartridge has a temperature resistance of 180℃ (65% stiffness retention rate after 500h aging), a stiffness of 1750mg, a 3.5MPa scouring time of 3.2min, a PTFE film peel strength of 6N / 25mm, and the structure is prone to collapse at high temperatures.

[0079] Comparative Example 4 Comparative Example 4 is basically the same as Example 3, except that in step (2), no bromotriazine is added to the flame retardant composite emulsion. That is, by weight ratio, 35% of composite flame retardant (ammonium polyphosphate and melamine cyanurate in a mass ratio of 60:40), 35% of composite stiffener (etherified melamine formaldehyde resin and hydroxyl silicone oil in a mass ratio of 82:18), 23% of deionized water, and 7% of reinforcing agent (γ-aminopropyltriethoxysilane) are stirred and mixed to obtain the flame retardant composite emulsion.

[0080] In this comparative example, the filter cartridge has a temperature resistance of 180℃ (60% stiffness retention rate after 500h aging), a stiffness of 1886mg, can withstand 3.5MPa scouring for 3.5min, and has a PTFE peel strength of 11N / 25mm. The bicomponent low-melting-point polyester staple fiber melts and softens above 180℃, which shows that bromotriazine can compensate for the temperature resistance defects of low-melting-point polyester.

[0081] Comparative Example 5 Comparative Example 5 is basically the same as Example 3, except that in step (1), the composite needle-punched felt was not subjected to hot pressing treatment, that is: the two layers of composite fiber mesh were bonded to a layer of glass fiber mesh base fabric (200g / m²). 2 Alternately lay the layers at a rate of 120 stitches / cm.2 The sandwich-like laminate was subjected to composite needling at a needling density and a needling depth of 8-12 mm to obtain a yield of 600 g / m³. 2 Composite needle-punched felt is used to obtain filter cartridge substrate.

[0082] In this comparative example, the filter cartridge has a temperature resistance of 180℃ (81% stiffness retention rate after 500h aging), a stiffness of 1850mg, and can withstand 3.5MPa erosion for 2.8min. The PTFE peel strength is 9N / 25mm. Due to the lack of hot pressing treatment, the bicomponent low melting point polyester staple fiber did not form three-dimensional bonding nodes, resulting in a loose fiber structure and reduced stiffness and erosion resistance of the filter cartridge.

[0083] Comparative Example 6: Comparative Example 6 is basically the same as Example 1, except that in step (2), the flame retardant in the flame retardant composite emulsion is only ammonium polyphosphate and the stiffening agent is only etherified modified melamine formaldehyde resin.

[0084] The filter cartridge in this comparative example has a temperature resistance of 225℃ (78% stiffness retention rate after 500h aging), a stiffness of 1847mg, can withstand 3.5MPa scouring for 3.7min, a PTFE peel strength of 15.5N / 25mm, and a filtration efficiency of 99.16%.

[0085] Comparative Example 7: Comparative Example 7 is basically the same as Example 1, except that in step (2), the reinforcing agent in the flame retardant composite emulsion is only bromotriazine.

[0086] The filter cartridge in this comparative example has a temperature resistance of 225℃ (80% stiffness retention rate after 500h aging), a stiffness of 1976mg, can withstand 3.5MPa scouring for 3.8min, a PTFE peel strength of 15.1N / 25mm, and a filtration efficiency of 99.47%.

[0087] The performance of the high-temperature resistant glass fiber composite folded filter cartridge samples provided in the examples and comparative examples was tested, and the test results are shown in Table 1 below: Among them, air permeability: refer to standard GB-T 5453-2025 Determination of air permeability of textile fabrics; filtration efficiency: refer to standard ISO 29463:2017 High-efficiency filters and filter media for removing particulates from the air; membrane erosion resistance: the time it takes for the membrane filter material to be eroded by a 3.5MPa high-pressure water gun; stiffness and stiffness retention rate: refer to standard test method for determining the bending strength of paper and paperboard (Gurley tester); temperature resistance: refer to standard test method in Appendix C of GB / T 6719 Technical requirements for bag filters; peel strength: GB / T 2791 Adhesives T Peel Strength Test Method.

[0088] Table 1 Performance test results of high-temperature resistant glass fiber composite pleated filter media As shown in Table 1, compared with Comparative Example 1, the temperature resistance, stiffness, and erosion resistance of the filter cartridges in Examples 1-5 are far superior to those in Comparative Example 1. This shows that the composite filter cartridge substrate and flame retardant composite system in this example can break through the upper limit of the temperature resistance of traditional filter cartridges. Compared with Comparative Example 2, Examples 1-5 maintain a temperature resistance of 230℃ while having higher stiffness, lower cost, and no recycling problems. This shows that the fiberglass mesh base fabric can replace the metal mesh.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a high-temperature resistant glass fiber composite folded filter cartridge, characterized in that, The preparation method includes the following steps: (1) Two layers of composite fiber mesh and one layer of glass fiber mesh base fabric are laid alternately to form a sandwich laminate. The sandwich laminate is then composite needle-punched to obtain a composite needle-punched felt. The composite needle-punched felt is then hot-pressed to obtain a filter cartridge substrate. The composite fiber mesh is formed by a mixture of two-component low-melting-point polyester short fibers, synthetic fibers and glass fibers. (2) The filter cartridge substrate is immersed in a flame retardant composite emulsion and dried to obtain a high-temperature resistant filter cartridge substrate; wherein the flame retardant composite emulsion is prepared by mixing a composite flame retardant, a composite stiffener, a reinforcing agent and water. (3) The surface of the high-temperature resistant filter cartridge substrate is coated and pleated in sequence to obtain the high-temperature resistant glass fiber composite pleated filter cartridge.

2. The preparation method according to claim 1, characterized in that, In step (1), the fineness of the bicomponent low-melting-point polyester staple fiber is 2~5D, the length is 38~64mm, and the melting point is 110~180℃; The synthetic fiber is at least one of aramid 1313 fiber, PPS fiber or polyimide fiber, and its length is preferably 38~51mm. The length of the glass fiber is 38~65mm.

3. The preparation method according to claim 1, characterized in that, In step (1), by mass percentage, the composite fiber web contains 15-30% bicomponent low-melting-point polyester staple fiber, 10-20% synthetic fiber, and 50-70% glass fiber.

4. The preparation method according to claim 1, characterized in that, In step (1), the basis weight of the fiberglass mesh is 120~420 g / m. 2 ; and / or The acupuncture density of the composite acupuncture is 80~350 needles / cm. 2 The needle-punching depth is 3~15mm, and the basis weight of the composite needle-punched felt is 450~760g / m². 2 .

5. The preparation method according to claim 1, characterized in that, In step (1), a three-roll calender is used to hot press the composite needle-punched felt; wherein the temperature of the upper roller is 50~150℃, the temperature of the middle roller is 110~220℃, and the pressure of the lower roller is 0.5~10MPa.

6. The preparation method according to claim 1, characterized in that, In step (2), the composite flame retardant is obtained by mixing and compounding ammonium polyphosphate and melamine cyanurate; preferably, the mass ratio of ammonium polyphosphate to melamine cyanurate is (55~65):(35~45). The composite stiffening agent is obtained by mixing and compounding etherified modified melamine-formaldehyde resin and hydroxyl silicone oil; preferably, the mass ratio of etherified modified melamine-formaldehyde resin to hydroxyl silicone oil is (80~85):(15~20). The reinforcing agent is γ-aminopropyltriethoxysilane and bromotriazine, preferably, the mass ratio of γ-aminopropyltriethoxysilane to bromotriazine is (1~5):(2~5).

7. The preparation method according to claim 1 or 6, characterized in that, In step (2), the flame retardant composite emulsion comprises, by mass percentage: 30-40% composite flame retardant, 30-40% composite stiffener, 3-10% reinforcing agent, and 25-35% water.

8. The preparation method according to claim 1, characterized in that, In step (2), the filler weight of the filter cartridge substrate after impregnation with the flame retardant composite emulsion is 105-120%; and / or The drying temperature is 180~230℃ and the time is 10~15min.

9. The preparation method according to claim 1, characterized in that, In step (3), the coating material is a PTFE film, the PTFE film has a pore size of 1~3μm, a porosity of 60%~90%, and a thickness of 2~15μm; and / or The temperature of the coating is 220~300℃ and the pressure is 1~3MPa.

10. A high-temperature resistant glass fiber composite pleated filter cartridge, characterized in that, It is prepared by any one of the preparation methods according to claims 1 to 9.

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