A fiber composite material for dust removal cloth bags and a method for preparing the same

Abstract

The application belongs to the technical field of functional fiber materials, and particularly relates to a fiber composite material for dust removal cloth bags and a preparation method thereof. The fiber composite material comprises the following raw materials in parts by weight: modified fiber 50-70 parts, LMPET 15-30 parts, PTFE fiber 10-15 parts, plant fiber 20 parts and impregnation liquid 60 parts. The modified fiber obtained by treating PPS with carbon black, titanium dioxide and PP-g-MAH has certain electrical conductivity and high wear resistance, can effectively reduce the electrostatic hazard in the dust adsorption process, improve the durability of the fiber composite material, the impregnation liquid can promote the high-temperature carbonization conversion of the plant fiber, can also penetrate and fill the fiber pores, form a protective layer with the characteristics of firmness, water repellency and oil repellency on the surface, and improve the high adsorption and service life of the fiber composite material.

Description

Technical Field

[0001] This invention belongs to the field of functional fiber materials technology, specifically relating to a fiber composite material for dust collector bags and its preparation method. Background Technology

[0002] Dust removal technology, as a key means of industrial flue gas purification, relies heavily on advancements in filter media materials for its performance. Currently, high-performance synthetic fibers such as polyphenylene sulfide (PPS) and polytetrafluoroethylene (PTFE) have become the mainstream base materials for filter media due to their excellent temperature resistance and chemical stability. Related research largely focuses on endowing materials with specific functions such as antistatic properties and water repellency through surface coatings or fiber blending. However, existing technologies suffer from limitations: surface functional coatings are prone to detachment and failure under long-term cleaning friction and chemical erosion, leading to performance degradation; while conventional physical blending of fibers struggles to achieve a balance between functional durability and matrix stability, often resulting in trade-offs. Related industries have long faced common challenges, including high filtration accuracy accompanied by high operating resistance, the mutual constraints between functionality and durability, and the difficulty in simultaneously achieving high ultrafine dust collection efficiency and cleaning effectiveness. Therefore, there is an urgent need for a dust removal material that combines antistatic properties, high adsorption capacity, and easy cleaning to address current industrial flue gas emissions and dust pollution problems. Summary of the Invention

[0003] To address the above issues, this invention provides a fiber composite material for dust collector bags and its preparation method. Maleic anhydride-grafted polypropylene is used as a compatibilizer to prepare functionally modified fibers. These fibers are then mixed with different types of fiber materials, such as plant fibers, to form a web. After light needle punching to form an entangled structure, the bonding fibers are melted and solidified through impregnation and a stepped heat treatment process, while the plant fibers are in situ transformed into porous biochar. Ultimately, a filter fiber composite material with a stable fiber network as its framework and a highly adsorbent functional interface as its main component is formed.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a fiber composite material for dust collector bags, the fiber composite material comprising the following raw materials in parts by weight: 50-70 parts modified fiber, 15-30 parts LMPET (low melting point polyester fiber), 10-15 parts PTFE (polytetrafluoroethylene) fiber, 20 parts plant fiber, and 60 parts impregnation liquid.

[0005] Furthermore, the plant fiber is selected from any one of wood pulp fiber, bamboo fiber, and lyocell fiber.

[0006] Furthermore, the impregnation solution is composed of ammonium dihydrogen phosphate, SiO2 (silicon dioxide), hydroxyl silicone oil, AEO (fatty alcohol polyoxyethylene ether), and deionized water in a mass ratio of 6:3:5:0.2:85.8.

[0007] Furthermore, the modified fiber comprises the following raw materials: PPS (polyphenylene sulfide), carbon black, titanium dioxide and PP-g-MAH (maleic anhydride grafted polypropylene), wherein the mass ratio of PPS, carbon black, titanium dioxide and PP-g-MAH is 80:10:5:5.

[0008] Furthermore, the modified fiber is prepared as follows: S1: Take carbon black, titanium dioxide and PP-g-MAH and premix for 5 min. Utilize the maleic anhydride polar groups and polymer chain structure in PP-g-MAH to pre-coat and isolate the carbon black and titanium dioxide particles to prevent subsequent particle agglomeration and obtain the premix. S2: The premix and PPS are melt-blended and granulated in a 1:1 mass ratio to achieve material compatibility and obtain masterbatch. The masterbatch is melt-blended and granulated again with the remaining PPS to dilute the masterbatch and further improve its dispersibility to meet the requirements of spinnability, thus obtaining spinning masterbatch. S3: The spinning masterbatch is melt-spun using a single-screw spinning machine. The screw temperature is 290℃, the box temperature is 310℃, and the spinneret temperature is 315℃. Hot drawing is performed using drawing rollers at a drawing ratio of 4 times and a drawing temperature of 90℃. After drawing, the fibers are cut into short fibers. The short fibers are then relaxed and heat-set in hot air to eliminate internal stress and improve the dimensional stability and mechanical properties of the short fibers, thus obtaining modified fibers.

[0009] This invention also provides a method for preparing fiber composite materials for dust collector bags, the specific steps of which are as follows: Step 1: Take 50-70 parts of modified fiber, 15-30 parts of LMPET, 10-15 parts of PTFE fiber, and 20 parts of plant fiber and put them into an opening machine for opening. Then, transfer them to a blending machine to mix and obtain dispersed fibers. Card the dispersed fibers and control the density to 400-600 g / m². 2 , thus obtaining a fiber web; Step 2: Feed the fiber web into the needle punching machine for needle punching, with a density of 50-80 needles / cm. 2 The entangled network fibers are formed. The entangled network fibers are immersed in 60 parts of impregnation solution and rolled with rollers to ensure that the impregnation solution is fully immersed in the entangled network fibers. After being taken out, they are naturally air-dried until no liquid drips, and a wet fiber web is obtained. Step 3: The wet fiber web is slowly dried in an 80℃ oven to initially remove moisture. The temperature is then increased to 130℃ to soften and melt the LMPET, promoting the adhesion of the wet fiber web. After high-temperature carbonization and ammonium dihydrogen phosphate catalysis, the plant fiber is transformed into biochar fiber, overcoming its defects in heat resistance and hydrolysis resistance, and producing a rich microporous structure, which improves the specific surface area and conductivity, and enhances the adsorption capacity for ultrafine dust, thus obtaining pretreated fiber. Step 4: Heat-set the pretreated fibers to eliminate internal stress, and then press, cut, and roll them up to obtain fiber composite materials for dust collector bags.

[0010] The beneficial effects achieved by this invention are as follows: This invention provides a fiber composite material for dust collector bags, which is a modified fiber prepared from PPS through treatment with carbon black, titanium dioxide, and PP-g-MAH. Due to its excellent electrical conductivity, it eliminates the electrostatic properties of other fiber materials and the electrostatic hazards during dust adsorption, complementing the inherent hydrophobic and oleophobic properties of PTFE fibers. The carbonization of plant fibers significantly enhances their specific surface area and microporous adsorption capacity. The process of melt spinning and impregnation with plant fibers, modified fibers, and polyester fibers not only facilitates the directional carbonization of plant fibers but also creates a functional interface with both high adsorption and easy-to-clean properties through film formation and hydrophobic properties of the impregnation solution, achieving high filtration, high adsorption, and low resistance. In the preparation process, the low-temperature bonding of the fibers through thermal melting achieves stable integration of the overall structure without introducing chemical adhesives, while the heat treatment strategy ensures the orderly connection of impregnation, drying, pre-curing, and high-temperature carbonization processes, guaranteeing the stability and mutual bonding of the functional components. The final product is a fiber composite material with properties such as antistatic properties, high-efficiency filtration, easy cleaning, high strength, and long life. Attached Figure Description

[0011] Figure 1 This is a flowchart illustrating the preparation process of a fiber composite material for dust collector bags according to the present invention. Figure 2 Microstructure of the fiber composite materials prepared in Example 2 and Comparative Example 1 was investigated. Figure 3 The results of the filtration resistance recovery rate of the fiber composite materials prepared in Examples 1-4 and Comparative Examples 1-2 are as follows; Figure 4 The resistivity results are for the fiber composite materials prepared in Examples 1-4 and Comparative Examples 1-2. Detailed Implementation

[0012] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0013] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to this invention. The preferred embodiments and materials described herein are for illustrative purposes only and do not limit the scope of this application.

[0014] Unless otherwise specified, the following embodiments are all conventional methods; the preparation process of the fiber composite material of the present invention is as follows: Figure 1 As shown; unless otherwise specified, all raw materials used in the following examples are new materials purchased from the market, and all parts are parts by weight. In the following examples and comparative examples, the carbon black used is N220 type with certain electrical conductivity; the titanium dioxide is mixed crystal type; the PP-g-MAH used is CMG9801; the melting point of the LMPET used is 110℃; and the density of the PTFE fiber used is 2.2 g / cm³. 3 The tensile strength is 1.3 cN / dtex; the wood pulp fiber used is softwood pulp fiber with a length of 2.5-4 mm and a diameter of 40-55 μm; the bamboo fiber used is 100% bamboo fiber single strand 21S; the lyocell fiber used is short fiber with an average length of 60 mm and an average diameter of 3 μm; the SiO2 used is hydrophobic with an average particle size of 45 nm; the AEO type used is AEO-9.

[0015] In the following examples and comparative examples, the impregnation solution consisted of 60 parts ammonium dihydrogen phosphate, 30 parts SiO2, 50 parts hydroxyl silicone oil, 2 parts AEO, and 858 parts deionized water.

[0016] In the following examples and comparative examples, the modified fiber comprises the following raw materials in parts by weight: 400 parts PPS, 50 parts carbon black, 25 parts titanium dioxide, and 25 parts PP-g-MAH. The preparation method of the modified fiber is as follows: S1: Take 50 parts of carbon black, 25 parts of titanium dioxide and 25 parts of PP-g-MAH and premix them in a high-speed mixer at 800 rpm for 5 minutes, controlling the material temperature at 80℃. Utilize the maleic anhydride polar groups and polymer chain structure in PP-g-MAH to pre-coat and isolate the carbon black and titanium dioxide particles to prevent subsequent particle agglomeration, thus obtaining a premix. S2: The premix and 100 parts of PPS are melt-blended and granulated in a twin-screw extruder at a screw speed of 300 rpm and an extrusion temperature of 300°C to achieve material compatibility and obtain masterbatch. The masterbatch is then mixed with the remaining 300 parts of PPS and melt-blended and granulated again at a screw speed of 250 rpm and an extrusion temperature of 310°C to dilute the masterbatch and further improve its dispersibility to meet the requirements of spinnability, thus obtaining spinning masterbatch. S3: The spinning masterbatch is melt-spun using a single-screw spinning machine. The screw temperature is 290℃, the spinneret temperature is 310℃, and the spinneret temperature is 315℃. The spinneret has circular capillary orifices with a diameter of 0.25 mm and an aspect ratio of 4. Side blowing is used with an air temperature of 20℃, an air velocity of 0.5 m / s, and an air humidity of 85%. The spinning speed is 400 m / min. Hot drawing is performed using drawing rollers. The first-stage drawing ratio is 2 times at a temperature of 70℃, the second-stage drawing ratio is 2 times at a temperature of 90℃, and the total drawing ratio is 4 times. After drawing, a filament bundle is obtained. The filament bundle is cut into short fibers of 35 mm. The short fibers are relaxed and heat-set in hot air at 130℃ for 15 min to eliminate internal stress and improve the dimensional stability and mechanical properties of the short fibers, thus obtaining modified fibers.

[0017] Example 1: This example provides a fiber composite material for dust collector bags, which includes the following raw materials in parts by weight: 50 parts modified fiber, 30 parts LMPET, 15 parts PTFE fiber, 20 parts wood pulp fiber and 60 parts impregnation liquid.

[0018] This embodiment also provides a method for preparing fiber composite materials for dust collector bags, the specific steps of which are as follows: Step 1: Take 50 parts of modified fiber, 30 parts of LMPET, 15 parts of PTFE fiber, and 20 parts of wood pulp fiber and put them into an opening machine for opening. Then, transfer them to a blending machine and mix for 15 minutes to obtain dispersed fibers. Card the dispersed fibers into a thin web in a single fiber state through a carding machine, and then lay them up through a cross-laying machine to control the density at 400 g / m². 2 , thus obtaining a fiber web; Step 2: Feed the fiber web into the needle punching machine for light needle punching, with a pre-punching density of 50 needles / cm. 2 The needle depth is 8 mm, inserted from the back of the fiber mesh, with a main needle density of 30 needles / cm. 2 The needle depth is 10 mm to form an entangled network fiber. The entangled network fiber is immersed in 60 parts of impregnation liquid and rolled with rollers to ensure that the impregnation liquid is fully immersed in the entangled network fiber. After being removed, it is naturally air-dried until no liquid drips, and a wet fiber web is obtained. Step 3: The wet fiber web is slowly dried in an 80℃ oven for 8 minutes to initially remove moisture. The temperature is then increased to 130℃ to soften and melt LMPET for 10 minutes to promote the adhesion of the wet fiber web. Then, it is carbonized at 450℃ for 25 minutes in a nitrogen atmosphere to transform the wood pulp fiber into biochar fiber, overcoming its defects in heat resistance and hydrolysis resistance, and producing a rich microporous structure, which improves the specific surface area and conductivity, and enhances the adsorption capacity for ultrafine dust, thus obtaining pretreated fiber. Step 4: Heat set the pretreated fibers at 200℃ for 5 minutes to eliminate internal stress. After pressing, cutting and winding, the fiber composite material for dust collector bags is obtained.

[0019] Example 2: This example provides a fiber composite material for dust collector bags, which includes the following raw materials in parts by weight: 60 parts modified fiber, 25 parts LMPET, 10 parts PTFE fiber, 20 parts lyocell fiber, and 60 parts impregnation liquid.

[0020] This embodiment also provides a method for preparing fiber composite materials for dust collector bags, the specific steps of which are as follows: Step 1: Take 60 parts of modified fiber, 25 parts of LMPET, 10 parts of PTFE fiber, and 20 parts of lyocell fiber and put them into an opening machine for opening. Then, transfer them to a blending machine and mix for 15 minutes to obtain dispersed fibers. Card the dispersed fibers into a thin web in a single-fiber state using a carding machine, and then lay them up using a cross-laying machine, controlling the density to 500 g / m². 2 , thus obtaining a fiber web; Step 2: Feed the fiber web into the needle punching machine for light needle punching, with a pre-punching density of 70 needles / cm. 2 The needle depth is 8 mm, inserted from the back of the fiber mesh, with a main needle density of 40 needles / cm. 2 The needle depth is 10 mm to form an entangled network fiber. The entangled network fiber is immersed in 60 parts of impregnation solution and rolled with rollers. After being taken out, it is naturally dried until no liquid drips, and a wet fiber web is obtained. Step 3: Dry the wet fiber web slowly in an 80℃ oven for 8 minutes to initially remove moisture, raise the temperature to 130℃ to soften and melt LMPET for 10 minutes to promote the adhesion of the wet fiber web, and then carbonize it at 450℃ for 25 minutes in a nitrogen atmosphere to obtain pretreated fiber. Step 4: Heat set the pretreated fibers at 200℃ for 5 minutes to eliminate internal stress. After pressing, cutting and winding, the fiber composite material for dust collector bags is obtained.

[0021] Example 3: This example provides a fiber composite material for dust collector bags, which includes the following raw materials in parts by weight: 70 parts modified fiber, 15 parts LMPET, 10 parts PTFE fiber, 20 parts bamboo fiber and 60 parts impregnation liquid.

[0022] This embodiment also provides a method for preparing fiber composite materials for dust collector bags, the specific steps of which are as follows: Step 1: Take 70 parts of modified fiber, 15 parts of LMPET, 10 parts of PTFE fiber, and 20 parts of bamboo fiber and put them into an opening machine for opening. Then, transfer them to a blending machine and mix for 15 minutes to obtain dispersed fibers. The dispersed fibers are then carded into a thin web in a single-fiber state by a carding machine and laid out by a cross-laying machine, controlling the density to 600 g / m². 2 , thus obtaining a fiber web; Step 2: Feed the fiber web into the needle punching machine for light needle punching, with a pre-punching density of 80 needles / cm. 2 The needle depth is 8 mm, inserted from the back of the fiber mesh, with a main needle density of 50 needles / cm. 2 The needle depth is 10 mm to form an entangled network fiber. The entangled network fiber is immersed in 60 parts of impregnation solution and rolled with rollers. After being taken out, it is naturally dried until no liquid drips, and a wet fiber web is obtained. Step 3: Dry the wet fiber web slowly in an 80℃ oven for 8 minutes to initially remove moisture, raise the temperature to 130℃ to soften and melt LMPET for 10 minutes to promote the adhesion of the wet fiber web, and then carbonize it at 450℃ for 25 minutes in a nitrogen atmosphere to obtain pretreated fiber. Step 4: Heat set the pretreated fibers at 200℃ for 5 minutes to eliminate internal stress. After pressing, cutting and winding, the fiber composite material for dust collector bags is obtained.

[0023] Example 4: This example provides a fiber composite material for dust collector bags, which includes the following raw materials in parts by weight: 55 parts modified fiber, 25 parts LMPET, 15 parts PTFE fiber, 20 parts lyocell fiber, and 60 parts impregnation liquid.

[0024] This embodiment also provides a method for preparing fiber composite materials for dust collector bags, the specific steps of which are as follows: Step 1: Take 55 parts of modified fiber, 25 parts of LMPET, 15 parts of PTFE fiber, and 20 parts of lyocell fiber and put them into an opening machine for opening. Then, transfer them to a blending machine and mix for 15 minutes to obtain dispersed fibers. Card the dispersed fibers into a thin web in a single-fiber state using a carding machine, and then lay them up using a cross-laying machine to control the density at 400 g / m². 2 , thus obtaining a fiber web; Step 2: Feed the fiber web into the needle punching machine for light needle punching, with a pre-punching density of 50 needles / cm. 2 The needle depth is 8 mm, inserted from the back of the fiber mesh, with a main needle density of 30 needles / cm. 2 The needle depth is 10 mm to form an entangled network fiber. The entangled network fiber is immersed in 60 parts of impregnation solution and rolled with rollers. After being taken out, it is naturally dried until no liquid drips, and a wet fiber web is obtained. Step 3: Dry the wet fiber web slowly in an 80℃ oven for 8 minutes to initially remove moisture, raise the temperature to 130℃ to soften and melt LMPET for 10 minutes to promote the adhesion of the wet fiber web, and then carbonize it at 450℃ for 25 minutes in a nitrogen atmosphere to obtain pretreated fiber. Step 4: Heat set the pretreated fibers at 200℃ for 5 minutes to eliminate internal stress. After pressing, cutting and winding, the fiber composite material for dust collector bags is obtained.

[0025] The difference between Comparative Example 1 and Example 2 is that no modified fiber was added; the remaining raw material composition and preparation steps are the same as in Example 2. The difference between Comparative Example 2 and Example 2 is that no impregnation solution was used; the remaining raw material composition and preparation steps are the same as in Example 2.

[0026] Microstructure characterization: The microstructure of the fiber composite materials prepared in Example 2 and Comparative Example 1 was examined using SEM (scanning electron microscopy). The results are shown in the figure. Figure 2 .

[0027] Dust removal efficiency evaluation: Using NaCl (sodium chloride) aerosol as the test index, the filtration performance of the fiber composite materials prepared in Examples 1-4 and Comparative Examples 1-2 was evaluated. The prepared fiber composite materials were fixed on the fixture of an automatic filter media tester. Under clean conditions, air was introduced at a flow rate of 20 L / min. After stabilization, the pressure difference was recorded as the initial resistance (P0). The process was then switched to NaCl aerosol to simulate dust filtration. Loading was stopped when the resistance rose to 1000 Pa. The stable filtration efficiency (η) and final resistance (P) were recorded. s After standard pulse cleaning of the fiber composite material, clean air is introduced again, and the above filtration and pulse cleaning process is repeated 50 times. The resistance (P) after cleaning is then recorded. r The results are shown in Table 1. The resistance recovery rate (%) was calculated as follows: (1-P) r / P s () × 100%, results are shown in Figure 3 .

[0028] Antistatic performance evaluation: The fiber composite materials prepared in Examples 1-4 and Comparative Examples 1-2 were placed in the test environment for 24 hours to achieve humidity equilibrium. The samples were placed in the electrode clamp of the electrometer, a test voltage of 20 V was applied, and after stabilization for 60 s, the resistance value was recorded and the resistivity was calculated. The results are shown in [Figure number missing]. Figure 4 .

[0029] Table 1 Filtration performance of fiber composite materials

[0030] Figure 2 The results showed that the fiber composite material prepared in Comparative Example 1 had a smooth fiber surface and no bonding phenomenon, while the fiber composite material prepared by adding modified fiber in Example 2 had fibers bonded to each other and could effectively filter dust, indicating that the melt bonding of PP-g-MAH in the modified fiber was effective and could form a relatively dense filter network at the micro level.

[0031] Figure 3The results showed that, compared with the fiber composites prepared in Examples 1-4, the resistance recovery rates of Comparative Examples 1 and 2 were lower, indicating that the modified fibers and impregnation liquid play an important role in improving the service durability and easy-to-clean properties of the fiber composites.

[0032] Figure 4 The results showed that the fiber composite materials prepared in Examples 1-4 had low resistivity and considerable conductivity. They could release the static electricity carried by the dust itself or generated by material collisions during filtration through the conductive fibers, thereby reducing the static electricity hazards of the dust and providing a certain degree of safety.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0034] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention. The actual application is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar methods and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a fiber composite material for dust collector bags, characterized in that, The fiber composite material comprises the following raw materials in parts by weight: 50-70 parts modified fiber, 15-30 parts LMPET, 10-15 parts PTFE fiber, 20 parts plant fiber, and 60 parts impregnation liquid; The impregnation solution is composed of ammonium dihydrogen phosphate, SiO2, hydroxyl silicone oil, AEO and deionized water in a mass ratio of 6:3:5:0.2:85.

8. The modified fiber comprises the following raw materials: PPS, carbon black, titanium dioxide, and PP-g-MAH. The preparation method of the modified fiber is as follows: S1: Take carbon black, titanium dioxide and PP-g-MAH and premix them to obtain a premix; S2: The premix is ​​first blended with an equal weight of PPS, and then blended with the remaining PPS and granulated to obtain spinning masterbatch; S3: Melt spinning the spinning masterbatch to obtain modified fibers; The preparation method of the fiber composite material is as follows: Step 1: Take modified fiber, LMPET, PTFE fiber and plant fiber, open, mix and comb them to obtain a fiber web; Step 2: After needle-punching the fiber web, roll it in the impregnation solution and air dry it to obtain a wet fiber web; Step 3: Dry and melt the wet fiber web in two steps, then carbonize it at high temperature to obtain pretreated fibers; Step 4: After heat setting, cutting, and winding the pretreated fibers, fiber composite materials for dust collector bags are obtained; In step 2, the density of the acupuncture process is controlled at 50-80 needles / cm. 2 ; In step 3, the two-step drying and melting process is as follows: first, dry at 80°C to remove moisture, and then raise the temperature to 130°C to promote the melting and bonding of LMPET.

2. The method for preparing a fiber composite material for dust collector bags according to claim 1, characterized in that, The mass ratio of PPS, carbon black, titanium dioxide and PP-g-MAH is 80:10:5:5; In step S3, the melt spinning process uses a single-screw spinning machine, and heat setting is performed after melt spinning is completed.

3. The method for preparing a fiber composite material for dust collector bags according to claim 1, characterized in that, The plant fiber is selected from any one of wood pulp fiber, bamboo fiber, and lyocell fiber.

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