CN119793069A

CN119793069A - Dust removal filter material with anti-condensation and self-cleaning properties and preparation method thereof

Info

Publication number: CN119793069A
Application number: CN202510278811.6A
Authority: CN
Inventors: 尹修阳; 冯阳; 王锋华; 徐彪
Original assignee: Jiangsu Aokai Environment Technology Co ltd
Current assignee: Jiangsu Aokai Environment Technology Co ltd
Priority date: 2025-03-11
Filing date: 2025-03-11
Publication date: 2025-04-11
Anticipated expiration: 2045-03-11
Also published as: CN119793069B

Abstract

The invention discloses a dedusting filter material with anti-dewing and self-cleaning properties and a preparation method thereof, relating to the technical field of filter materials, wherein the filter material consists of a filter material main body and a surface treatment layer, the fiber of the filter material main body can be selected from a plurality of materials, the surface treatment layer mainly comprises perfluoro and polyfluoroalkyl compounds containing carbon atom straight chains, organic fluorosilicone modified acrylic ester compounds and ethoxy nonionic fluorocarbon surfactants, and the preparation method comprises the steps of filter material main body preparation, surface coating treatment liquid preparation, surface coating spraying, drying and shaping treatment and the like. The invention can effectively improve the performance of the filter material under complex working conditions, and has good comprehensive performances of condensation resistance, self-cleaning, water resistance, oil resistance, filtration and the like under high-temperature, high-humidity or oil-containing environments. The water repellency grade of the filter material reaches more than 4 levels, the oil repellency grade can reach more than 7 levels, the outlet concentration can be effectively reduced, the circulation time is prolonged, and the dust removal rate can reach more than 99.99%.

Description

Dedusting filter material with anti-condensation and self-cleaning properties and preparation method thereof

Technical Field

The invention relates to the technical field of filter materials, in particular to a dust removal filter material with anti-condensation and self-cleaning properties and a preparation method thereof.

Background

The bag type dust collector is widely applied to the industrial fields of coal-fired power plants, steel smelting, cement production, glass manufacturing and the like by virtue of high-efficiency dust removal capability, simple structure and convenient maintenance mode. However, in actual operation, the filter bag is often subjected to the comprehensive influence of factors such as moisture, oil mist, high temperature and the like due to complex and changeable working conditions, so that the performance of the filter material is reduced and even fails. Among them, the problem of "sticking a bag" is particularly remarkable, and has become one of the main problems that restrict the stable operation of the bag filter. The phenomenon of 'sticking a bag' refers to the situation that dust and filter material dust-facing surfaces or internal fibers are bonded to block filter material pores under the condition of high humidity environment or smoke containing oily substances, so that the air permeability is drastically reduced, and the equipment resistance is remarkably increased. This not only directly affects the operating efficiency of the dust collector, but also increases energy consumption, shortens the filter bag life, and even causes system downtime and high maintenance costs for frequent replacement of filter bags.

At present, the problem of 'sticking a bag' in the industry is mainly solved by adopting methods such as coating and dipping treatment, adding chemical water-repellent and oil-repellent agents, coating treatment and the like, and although the problem of 'sticking a bag' is relieved to a certain extent by the technology, the effect is often limited by the use environment, particularly in a high-temperature, high-humidity or oil-containing environment, the anti-condensation and anti-adhesion capabilities of the existing filter bag materials are difficult to stably maintain for a long time in a conventional treatment mode, and the waterproof and oil-repellent grades are easy to lose efficacy under a certain temperature through field application feedback and laboratory high-temperature tests. Therefore, a novel filter material with anti-condensation, self-cleaning capability and durable oil-proof performance is urgently needed to meet the use requirement under complex working conditions and effectively solve the problem of sticking a bag.

The Chinese patent with publication number CN115970395A discloses a waterproof and wear-resistant treatment method of a terylene filter material and a prepared filter material, wherein the method prepares and uses nano-scale silica aerogel/waterproof and oil-proof composite impregnating solution to impregnate the terylene filter material, so that the wear resistance and the waterproof performance of the filter material of the terylene filter material are increased at the same time, and the main focus of the patent is probably to improve the wear resistance and the waterproof performance of the filter material at the same time, but the focus on the oil-proof performance of the filter material and the long-term effectiveness at high temperature are ignored.

The Chinese patent with publication number of CN102392355A discloses a preparation method of a water-repellent oil-proof filter material easy to clean, which adopts PTFE emulsion and long-chain alkyl silicone oil to compound and carry out common dipping treatment on the filter material so as to realize the water-repellent oil-proof performance. However, in an actual industrial environment, the dust has complex and various components, and the water and oil repellency of the PTFE emulsion cannot effectively prevent agglomeration and adhesion of the dust because the water and oil repellency of the PTFE emulsion is not comprehensive enough to resist the paste bag by only relying on the water and oil repellency of the PTFE emulsion, so that the paste bag phenomenon still occurs.

Disclosure of Invention

The invention aims to solve the technical problems, and provides a dust removal filter material with anti-condensation and self-cleaning properties and a preparation method thereof, and the dust removal filter material can effectively overcome the defects of the prior art, meet the requirement of complex working conditions and solve the problem of bag pasting through specific surface treatment.

In order to achieve the technical aim and meet the technical requirements, the invention adopts the technical scheme that the dust-removing filter material with anti-condensation and self-cleaning properties comprises a filter material main body and a surface treatment layer, wherein the filter material main body is a filter felt prepared by adopting a needling process;

The surface treatment layer at least contains one component, wherein the component is a perfluoro and polyfluoroalkyl compound containing a carbon atom linear chain, the compound is uniformly covered on the surface of the fiber layer, the adhesion amount of the compound on a filter material solid is 5-40 g/m ², the surface treatment component is uniformly covered on the surface of the fiber at the thickness of 0-50 microns of the surface and covers at least 90% of the area of the surface of the fiber, the surface treatment component covers at least 75% of the area of the surface of the fiber at the thickness of 50-100 microns of the surface downwards, and the surface treatment component covers less than or equal to 20% of the area of the surface of the fiber at the thickness of 200 microns of the surface downwards.

The linear perfluoro and polyfluoroalkyl compounds of carbon atoms in the surface treatment layer are preferably in the form of linear chains of six or more carbon atoms.

The surface treatment layer also contains an organic fluorosilicone modified acrylic ester compound, the modifier is an antifouling and soft composite modifier, and the solid adhesion amount is 2-10 g/m ².

The surface treatment layer also contains an ethoxy nonionic fluorocarbon surfactant, and the solid attachment amount is 1-3 g/m < 2 >.

The filter material main body fiber is preferably one or a mixture of more of PPS fiber, aramid fiber, glass fiber, basalt fiber, polyimide, polytetrafluoroethylene and the like.

The method for preparing the dust removal filter material with the dewing resistance and the self-cleaning performance comprises the following steps:

Preparing a filter material main body, namely selecting fibers and base cloth, opening, mixing, finely opening, carding, lapping, adding the base cloth and needling short fibers to prepare a semi-finished needled felt, controlling the unit gram weight to be 400-900 g/m ², and carrying out different modes of singeing, calendaring, heat setting and the like on the prepared filter felt according to requirements;

preparing a surface coating treatment liquid, namely preparing 5-40 g/m2 of linear perfluoro and polyfluoroalkyl compounds with carbon atoms, 2-10 g/m2 of organosilicon modified acrylic ester compounds, 1-3 g/m2 of ethoxy nonionic fluorocarbon surfactant, optionally adding a certain amount of cross-linking agent and stabilizing agent into the prepared treatment liquid, and the balance of water according to the adhesion quality of solid on the surface of a filter material;

The surface coating is sprayed and uniformly coated on the surface of the high-temperature resistant fiber layer in a spraying mode, the spraying distance in the spraying process is 15cm-30cm, the front-back deflection of the spraying inclined angle is less than or equal to 45 degrees by taking the vertical filter material as a standard, the relative humidity is 40% -70%, and the environmental temperature is controlled to be 10 ℃ -35 ℃;

and fourthly, drying and shaping the prepared filter material to improve performance stability, wherein the drying and shaping temperature is preferably three temperature ranges, namely, one range is 80-120 ℃, the treatment time is 1-2 minutes, the second range is 120-160 ℃, the treatment time is 1-2 minutes, and the third range is 160-220 ℃ and the treatment time is 5-10 minutes.

The cross-linking agent in the second step is preferably a silane coupling agent with the addition content of 1-3%, and the stabilizer is preferably one of Butyl Hydroxy Anisole (BHA) or BHT (tert-butyl hydroquinone) with the addition content of 0.5-2%.

The dust-removing filter material with anti-condensation and self-cleaning performances has a water-repellent grade and an oil-repellent grade which are tested on the basis of GB/T4745-2012 water-repellent detection and evaluation method for textile fabrics, wherein the water-repellent grade of the filter material reaches more than 4 levels, and the oil-repellent grade can reach more than 7 levels.

The dedusting filter material with anti-condensation and self-cleaning performances adopts VDI3926-1:2004"Testing of cleanable filter media - Standard test for the evaluation of cleanable filter media" to evaluate the filtering performance, and the dedusting rate can reach more than 99.99 percent.

Compared with the traditional structure, the invention has the beneficial effects that:

1. The surface treatment layer realizes gradient coverage on the surface of the filter material, can realize higher-grade waterproof, oil-proof and antifouling performances, can effectively improve the performances of the filter material under complex working conditions, has good comprehensive performances of condensation resistance, self-cleaning, water-proof and oil-proof, filtering and the like under high-temperature, high-humidity or oil-containing environments, can realize long-term stable maintenance of the condensation resistance and the adhesion resistance of the filter bag material, and effectively inhibits the filter bag pasting;

2. the water-repellent grade of the filter material reaches more than 4 levels, the oil-proof grade can reach more than 7 levels, the outlet concentration can be effectively reduced, the circulation time is prolonged, the dust removal rate can reach more than 99.99%, and the filter material has wide application prospect in the industrial dust removal and civil fields.

Detailed Description

The present invention will be further described below.

The dust removing filter material with the dewing resistance and the self-cleaning performance comprises a filter material main body and a surface treatment layer, wherein the filter material main body is a filter felt prepared by a needle punching process, the unit gram weight is preferably 400-900g/m < 2 >, and the fiber is preferably one or a mixture of more of PPS fiber, aramid fiber, glass fiber, basalt fiber, polyimide, polytetrafluoroethylene and the like.

Selecting proper fibers (and base cloth), and sequentially performing the procedures of opening, mixing, fine opening, carding, lapping, base cloth adding, needling and the like on the short fibers to prepare a semi-finished needled felt.

The surface treatment layer of the filter material contains at least one component which is a perfluoro or polyfluoroalkyl compound having a linear carbon atom chain, preferably having a linear carbon atom chain form of six or more. The adhesion amount of the compound in the filter material solid is preferably 5-40 g/m ². The linear perfluoro and polyfluoroalkyl compounds with carbon atoms can form a layer of compact and stable protective film on the surface of the material, and the protective effect of the compound is obviously superior to that of a plurality of common waterproofing agents. Compared with the common waterproof agent, the long carbon chain makes the acting force among molecules stronger, the molecular arrangement is tighter, and the critical surface tension is lower. At the same time, the presence of fluorine atoms further enhances this effect. The fluorine atoms have strong electronegativity, and can attract electrons, so that electron cloud distribution around the molecules is tighter, the attractive force between the molecular chains is increased by the compact electron cloud structure, and the formed waterproof film is denser. The film can not only effectively block the permeation of water molecules, but also play a role in rejecting oil molecules, so that the material has excellent water and oil resistance, but when the number of carbon atoms is less than 6, the stability of the water and oil resistance is greatly reduced. Experiments show that when the solid adhesion amount of the perfluoro and polyfluoroalkyl compounds with the straight chain carbon atoms on the filter material is 5-40 g/m < 2 >, the compounds form a uniform gradient coverage structure between fiber layers. When the adhesion amount is less than 5g/m2, a complete protective film cannot be formed, and the compound is difficult to fully cover the surface of the fiber, so that the water and oil resistance cannot meet the requirements of the scheme. When the adhesion amount is higher than 40g/m < 2 >, on one hand, pores among fibers can be blocked, the air permeability of the filter material is affected, so that the filtration performance is reduced and the energy consumption is increased due to high pressure loss during filtration, and on the other hand, excessive compounds can be accumulated on the surface of the material to form uneven coating, so that the stability of the protective effect is poor.

The gradient adhesion structure is that the fiber surface at the 0-50 micron thickness of the surface is covered uniformly, and the surface treatment component covers at least 90% of the area of the fiber surface, the area is the part directly contacted with the external environment, which is the first defense line for preventing water and oil from penetrating, if the area is less than 90%, water molecules and oil molecules can easily enter the material through the gaps. The waterproof and oil-proof properties of the material cannot meet the requirements, and once the liquid enters, the internal structure of the material is affected, such as bonding of fibers, easy penetration of dust and further unsatisfactory filtration efficiency, at the position of 50-100 microns in thickness, the surface treatment component covers at least 75% of the area of the surface of the fibers, the deep area is not directly contacted with the external environment, but still affected by the penetration of the liquid, if the coverage area is insufficient, the liquid gradually penetrates into the area due to incomplete protection layer, the filtration performance cannot meet the requirements, the dust outlet concentration is increased, the pressure loss is increased, at the position of 200 microns below the surface, the surface treatment component covers less than or equal to 20% of the area of the surface of the fibers, the performance is maintained in the deeper area mainly by the structure of the material itself and the protection of the upper layer, if the surface treatment component is too large, the micro-structure of the inside of the material is excessively changed, pores among the fibers are blocked, the air permeability and the filtration performance of the material cannot meet the requirements, and excessive compounds also increase the cost and weight of the material in the area, and the actual application requirements cannot be met.

The surface of the filter material also contains organic fluorine silicon modified acrylic ester compound, and the solid attachment amount of the organic fluorine silicon modified acrylic ester compound on the surface of the fiber is preferably 2-10g/m < 2 >. Such organofluorosilicone modified acrylate compounds can produce synergistic effects with the previously mentioned perfluoro and polyfluoroalkyl compounds (water repellents) containing a straight chain of carbon atoms. The waterproof agent mainly focuses on preventing water and oil from penetrating, and the organic fluorine silicon modified acrylic ester compound can further reduce the dust adhesion rate on the surface of a filter material, achieves the effect of easy ash removal and low adhesion, and forms a complementary protection system. For example, after the waterproof agent prevents the penetration of liquid, the organic fluorine silicon modified acrylic ester compound can prevent solid dirt such as dust from being adsorbed on the surface of the fiber in a humid environment, so that the integral anti-fouling capability of the material is greatly improved, when the adhesion amount of the organic fluorine silicon modified acrylic ester compound is less than 2g/m < 2 >, the fiber surface cannot be uniformly covered, the anti-fouling performance is not obviously improved, when the adhesion amount of the organic fluorine silicon modified acrylic ester compound is more than 10g/m < 2 >, excessive compound is accumulated on the surface of the fiber, the original reasonable protective structure is damaged, the cost is increased, the anti-fouling effect is not further improved, and the filtering efficiency is reduced.

The surface of the filter material also contains an ethoxy nonionic fluorocarbon surfactant, and the solid attachment amount of the ethoxy nonionic fluorocarbon surfactant on the surface of the fiber is preferably 1-3g/m <2 >. The surfactant is capable of reducing the surface tension of the solution, changing the interfacial properties between the solution and the material. The surfactant forms an adsorption layer on the surface of the fiber, so that some solute molecules are preferentially adsorbed on the layer, and along with the impregnation, the adsorption and diffusion of the solute also show gradient change due to the distribution gradient of the surfactant, so that an impregnation layer with higher concentration is formed on the surface of the material, the degree of impregnation in the material is gradually reduced, and the gradient layering effect of the coating is generated. The surface treatment layer uniformly covers the fiber surface at the thickness of 0-50 microns and at least 90% of the area of the fiber surface, the surface treatment component covers at least 75% of the area of the fiber surface at the thickness of 50-100 microns, and the surface treatment component covers less than or equal to 20% of the area of the fiber surface at the thickness of 200 microns below. When the adhesion rate of the ethoxy nonionic fluorocarbon surfactant is less than 1g/m <2 >, a complete and effective adsorption layer cannot be formed on the surface of the fiber due to the fact that the amount of the surfactant is too small, the surface tension of the solution cannot be sufficiently reduced, the effect of changing the interface property is poor, adsorption of solute molecules becomes disordered and insufficient, an ideal concentration gradient cannot be formed in the impregnation process, further the coating is difficult to produce an expected gradient layering effect, the quality of the final product is reduced, and the problems of uneven thickness of the coating, insufficient internal impregnation and the like can occur, so that the performance of a filter material, such as filtration efficiency and stability, is influenced. When the adhesion rate of the ethoxy nonionic fluorocarbon surfactant is more than 3g/m <2 >, excessive surfactant can generate an excessively thick adsorption layer on the surface of the fiber, which can cause the adsorption layer to be too viscous, solute molecules are excessively accumulated on the surface, so that channels on the surface are blocked, and the normal diffusion of the solute into the material is blocked. Moreover, such an excessively thick adsorption layer may cause uneven distribution of internal stress of the coating, so that the coating is easily cracked or peeled off. Meanwhile, too much surfactant can increase production cost and have adverse effects on the subsequent processing process and other properties of the product, such as the problem of poor air permeability of the filter material or easier adsorption of impurities in the actual use process.

The preparation of the surface coating treatment liquid of the dust-removing filter material comprises the steps of preparing the surface coating treatment liquid according to the adhesion quality of solid on the surface of a filter material, wherein the linear perfluoro and polyfluoroalkyl compounds with carbon atoms are 5-40 g/m < 2 >, the organosilicon modified acrylic ester compounds are preferably 2-10 g/m < 2 >, the ethoxy nonionic fluorocarbon surfactant is preferably 1-3 g/m < 2 >, and the surface coating treatment liquid is prepared by adding one of silane coupling agent (the addition content is 1-3%), stabilizer BHA (butyl hydroxy anisole) or BHT (tertiary butyl hydroquinone), the addition content is 0.5-2% and the balance of water. The silane coupling agent is added to facilitate the uniform coverage of the coating on the surface of the fiber, so that the rheological property of the coating solution can be regulated, the dispersion and the distribution of each component are promoted, and the gradient layering effect of the power-assisted coating is generated. Meanwhile, one end of the silicon oxygen radical can react with hydroxyl on the surface of the fiber to form a chemical bond, and the other end of the organic radical can interact with organic components of the coating, so that the bonding strength between the coating and the fiber is obviously enhanced. When the addition amount is less than 1%, the interface between the inorganic component and the organic coating on the surface of the filter material cannot be fully covered, so that the binding force between the coating and the filter material is insufficient, and the durability of the filter material is reduced. Because the amount of the silane coupling agent is too small, a sufficient chemical bond or physical adsorption cannot be formed to enhance the adhesion of the interface. And when the addition amount is more than 3%, the excessive silane coupling agent may form an agglomeration phenomenon in the coating. These agglomerates can affect the uniformity of the coating, resulting in a change in coating properties in localized areas, a decrease in coating air permeability, a rise in pressure loss, and excessive silane coupling agents can increase costs and reduce the cost performance of the product. The stabilizers BHA (butyl hydroxy anisole) or BHT (tertiary butyl hydroquinone) are mainly intended to prevent oxidation of the components in the coating during storage or use. If the addition amount is less than 0.5%, the antioxidant capacity is insufficient. In practical environments, the coating material undergoes oxidation reaction due to exposure to oxygen, ultraviolet light, etc., resulting in degradation of coating properties such as discoloration, embrittlement, etc. On the other hand, when the addition amount exceeds 2%, other properties of the coating layer are adversely affected, such as changing the chemical stability of the coating layer, resulting in adverse reactions with other components. On the other hand, too much stabilizer increases the production cost and affects the physical properties of the coating to some extent, such as increasing the hardness of the coating, deteriorating the flexibility, etc.

And (3) spraying the surface coating of the dedusting filter material, namely uniformly coating the treatment liquid on the surface of the high-temperature-resistant fiber layer in a spraying mode, wherein the spraying distance is preferably 15cm-30cm in the spraying process, the front-back deflection of the spraying angle coating inclination angle taking the direction perpendicular to the filter material as a standard is less than or equal to 45 degrees, the relative humidity is preferably 40-70%, and the environment temperature is preferably 10-35 ℃. Through a large number of experiments, the coating can obtain the optimal gradient distribution effect when the process parameters are selected. When the spraying distance is less than 15cm, the impact force of the treatment liquid sprayed by the spray gun is large and the treatment liquid is not easy to disperse under the action of high pressure, so that the sprayed liquid is locally concentrated and unevenly distributed, the treatment liquid is easy to permeate deeper, and the emulsion is not easy to concentrate on the surface of the fiber, so that the uniformity and the surface performance of the coating, such as surface flatness, glossiness and the like, are affected. And too close a distance can cause too thick coating in some areas, so that defects such as cracking easily occur in the drying process, and waste of treatment fluid can be caused. When the spraying distance is more than 30cm, the treatment fluid can be greatly diffused and scattered before reaching the surface of the fiber, so that the amount of the treatment fluid effectively attached to the fiber layer is reduced, the thickness of the coating is difficult to reach the expected standard, the integrity and the functionality of the coating are affected, and a continuous, uniform and protective coating with enough thickness cannot be formed, so that the filtration efficiency and the service life of the dust removal filter material are reduced. When the spraying angle is greater than +/-45 degrees, the coating direction of the treatment fluid on the fiber surface is too inclined, most of the treatment fluid can drift into the surrounding environment and cannot be effectively coated on the fiber surface, the treatment fluid cannot be uniformly attached to the fiber surface, the coating thickness is uneven, the condition that the coating is missing or too thin can occur in partial areas, and the overall performance of the dedusting filter material is further affected, such as the interception effect and the anti-pollution capability of the dedusting filter material on dust and other particles are reduced. Most of the treatment liquid can fly to the surrounding environment and cannot be effectively coated on the surface of the fiber, so that a large amount of waste and environmental pollution of the treatment liquid are caused, and meanwhile, the effective coating treatment of the fiber layer cannot be realized completely, so that the dust removal filter material cannot obtain the expected surface coating performance. When the relative humidity is lower than 40%, the environment is too dry, the moisture in the treatment fluid can be quickly evaporated, the viscosity of the treatment fluid can be changed in the spraying process, the treatment fluid becomes too thick, the fluidity and the atomization effect of the treatment fluid are affected, the spraying is uneven, particles or blocks are easily formed and stacked on the surface of the fiber, and the uniform coating is not formed, so that the quality of the coating and the filtering performance of the dust-removing filtering material are affected. When the relative humidity is higher than 70%, the ambient humidity is higher, the evaporation rate of the water in the treatment fluid is slower, the coating can be dried for too long, impurities and dust in the air are easily adsorbed in the drying process, the surface of the coating is polluted, the chemical reactivity of certain components in the treatment fluid can be influenced by the high humidity environment, the binding force between the coating and the fiber is reduced, and the durability and the stability of the coating are poor. When the ambient temperature is lower than 10 ℃, the viscosity of the treatment liquid is increased, the fluidity is poor, atomization and uniform coating in the spraying process are not facilitated, and the problems of uneven thickness, rough surface and the like of the coating are caused. Meanwhile, the reactivity of some components in the treatment fluid is reduced in a low-temperature environment, the curing speed and quality of the coating are affected, the adhesion between the coating and the fiber is unstable, and the performance and the service life of the dedusting filter material are reduced. When the ambient temperature is higher than 35 ℃, the volatilization speed of components such as solvent in the treatment liquid is too high, so that the concentration of the treatment liquid changes in the spraying process, the uniformity and the stability of the treatment liquid are affected, and defects such as uneven coating surface, bubbles and the like are easy to occur. And the high temperature environment can decompose or denature some components in the treatment fluid, destroy the structure and the performance of the coating, and reduce the protection effect and the reliability of the dust removal filter material.

And (3) drying and shaping the surface of the dust-removing filter material, namely drying and shaping the prepared filter material to improve the performance stability of the filter material. In order to obtain a stable gradient structure of the surface coating, the drying and shaping temperature is preferably three intervals, one is 80-120 ℃ and the treatment time is 1-2 minutes, the stage mainly comprises the steps of uniformly distributing the waterproof agent in the filter material, enabling the excessive moisture in the system to volatilize at a lower temperature to prevent the coating from gathering on the surface of the material due to rapid evaporation, enabling the coating to fully permeate among fibers in the material, the other is 120-160 ℃ and the treatment time is 1-2 minutes, enabling the surface coating to begin to be primarily solidified, enabling the moisture to continuously volatilize, enabling some components in the reagent to gradually transform from a liquid state to a solid state along with the rising of the temperature, enabling the components to be better adhered to the surface of the fibers of the filter material, and the three is 160-220 ℃ and the treatment time is 5-10 minutes, which is a key stage of drying and shaping, and in this high-temperature stage, the coating is fully solidified to form a more stable and compact waterproof structure, and high-temperature can enable chemical bonds in the waterproof agent to fully react with the fibers of the filter material.

Various performance tests of the filter material of the present invention are as follows, but are not limited to these tests.

The method for testing the surface adhesion proportion of the dust-removing filter material comprises the step of analyzing the adhesion condition of a fiber surface coating by combining the SEM, ultraviolet-visible spectrum (UV-Vis) technology and Raman spectrum technology of fibers at different positions.

Testing the water-proof and oil-proof performance of the surface of the dust-removing filter material, namely testing the water-proof grade and the oil-proof grade of the filter material based on GB/T4745-2012 method for detecting and evaluating the water-proof performance of textiles so as to evaluate the performance of the filter material in water-proof and oil-proof aspects.

The water repellency performance comprises the steps of taking at least 18 x 18cm of flat filter material, clamping the filter material on a clamp after humidity adjustment (the clamp forms an angle of 45 degrees with the horizontal plane), pouring 250ml of water into a funnel rapidly and stably, continuously spraying for 25-30 s, taking off a clamp holder with a sample after stopping spraying, tapping the clamp holder against a solid hard object once horizontally from the front, rotating the clamp holder for 180 degrees again, and finally evaluating according to a water dipping rating. For the scheme, the water repellent effect is more than or equal to grade 4 and is qualified.

The oil repellency is that the front surface is spread on a liquid absorption pad on a smooth horizontal plane, and 5 small drops (the volume is about 0.05 ml) are dripped on a tested sample from the oil liquid with the number of 1, the interval between the drops is 4cm, the distance between the mouth of a dropper and the surface of the sample is 6mm, the drops are observed for 30s plus or minus 2s at an angle of 45 degrees, and the evaluation is carried out according to an evaluation standard and a comparison chart. For the case, the oil-repellent effect is more than or equal to 7 grades and is qualified.

And (3) evaluating the surface filtering performance of the dedusting filter material, namely evaluating the filtering performance of the filter material by VDI3926 - 1:2004"Testing of cleanable filter media - Standard test for the evaluation of cleanable filter media" so as to determine the filtering effect and efficiency of the dedusting filter material in practical dedusting application.

The performance of the filter material was determined based on the VDI3926 standard, the size of the test sample was 150mm in diameter, the concentration of the fed dust was 5.0.+ -. 0.5g/m ³, and the filtration wind speed was 2m/min (wind volume 1.85m ³/h). The experimental sequence was initial 30 rounds + stabilization 5000 rounds + final 30 rounds. The initial 30 rounds and the final 30 rounds are that the pressure difference across the filter material gradually increases with the operation time, when the pressure difference reaches 1000Pa, the dust on the surface of the filter material is cleaned by the pulse air, then the next process is carried out, the process is repeatedly carried out for 30 rounds, the change of the experiment time (t/s) and the pressure is recorded in the experiment process, and the weight M (g) of the dust penetrating through the filter material is weighed. The stabilization process is to remove ash from the filter material at intervals of 5s, the ash removal pressure is 5bar, and the ash removal times are 5000 times. The calculation formula of the outlet dust concentration and the trapping efficiency is as follows:

Outlet dust concentration C = weight of dust passing through the filter material M/(1.85 x time t/3600), the unit of outlet dust concentration C being g/M ³;

Trapping efficiency= (1-outlet dust concentration C/5) ×100%;

The pressure loss is automatically recorded by the equipment after the last injection of the last 30 times;

The cycle time is the total time spent for the last 30 rounds.

The present invention will be described in further detail with reference to specific examples and comparative examples, but the present invention is not limited to these examples.

In the embodiment 1, a mixture of aramid fibers is selected as main fibers of a filter material, and a semi-finished needled felt with the unit gram weight of 600g/m < 2 > is prepared through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 8g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

Example 2A semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared by adopting a mixture of aramid fibers as main fibers of a filter material through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

Example 3A semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared by adopting a mixture of aramid fibers as main fibers of a filter material through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to lead the surface solid content to be 35g, the surface solid content of the organic fluorosilicone modified acrylic ester compound to be 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant to be 2.5g, the content of the silane coupling agent to be 2.5%, the content of BHT (tertiary butyl hydroquinone) to be 1.5% and the balance to be water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

Example 4A semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared by adopting a mixture of aramid fibers as main fibers of a filter material through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, linear perfluoro and polyfluoroalkyl compounds with six carbon atoms are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

Example 5A semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared by adopting a mixture of aramid fibers as main fibers of a filter material through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 3g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

Example 6A semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared by adopting a mixture of aramid fibers as main fibers of a filter material through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 9g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

Example 7A semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared by adopting a mixture of aramid fibers as main fibers of a filter material through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 15g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

Example 8A semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared by adopting a mixture of aramid fibers as main fibers of a filter material through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 1.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

Example 9A semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared by adopting a mixture of aramid fibers as main fibers of a filter material through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

Example 10 a mixture of aramid fibers was used as the main fibers of the filter material, and a semi-finished needled felt with a unit gram weight of 600 g/m2 was produced by opening, mixing, etc., and heat setting treatment was performed. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

In the embodiment 11, the mixture of aramid fibers is selected as main fibers of the filter material, and the semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 1.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

In the embodiment 12, the mixture of aramid fibers is selected as the main fibers of the filter material, and the semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

In the embodiment 13, the mixture of aramid fibers is selected as main fibers of the filter material, and the semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

Example 14A semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared by adopting a mixture of aramid fibers as main fibers of a filter material through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHA (butyl hydroxy anisole) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

Example 15A semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared by adopting a mixture of aramid fibers as main fibers of a filter material through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 8g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

Example 16A semi-finished needled felt with the unit gram weight of 600 g/m < 2 > is prepared by adopting a mixture of aramid fibers as main fibers of a filter material through the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 8g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 1.

In comparative example 1, a mixture of aramid fibers was used as the main fibers of the filter material, and a semi-finished needled felt having a unit gram weight of 600 g/m2 was produced by the steps of opening, mixing, and the like, and heat setting treatment was performed. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 1g, the surface solid content of the organic fluorosilicone modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 2.

Comparative example 2a semi-finished needled felt with a unit gram weight of 600 g/m2 was prepared by using a mixture of aramid fibers as the main fibers of the filter material through the steps of opening, mixing, and the like, and heat setting treatment was performed. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to lead the surface solid content to be 3g, the surface solid content of the organic fluorosilicone modified acrylic ester compound to be 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant to be 2.5g, the content of the silane coupling agent to be 2.5%, the content of BHT (tertiary butyl hydroquinone) to be 1.5% and the balance to be water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 2.

In comparative example 3, a mixture of aramid fibers is selected as the main fibers of the filter material, and a semi-finished needled felt with a unit gram weight of 600 g/m2 is prepared by the procedures of opening, mixing and the like, and is subjected to heat setting treatment. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 45g, the surface solid content of the organic fluorosilicone modified acrylic ester compound is 0.5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 2.

Comparative example 4a semi-finished needled felt with a unit gram weight of 600 g/m2 was prepared by using a mixture of aramid fibers as the main fibers of the filter material through the procedures of opening, mixing, etc., and heat setting treatment was performed. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 60g, the surface solid content of the organosilicon modified acrylic ester compound is 15g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 2.

Comparative example 5a semi-finished needled felt with a unit gram weight of 600 g/m2 was prepared by using a mixture of aramid fibers as the main fibers of the filter material through the procedures of opening, mixing, etc., and heat setting treatment was performed. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 8g, the surface solid content of the organic fluorosilicone modified acrylic ester compound is 0.5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 2.

Comparative example 6 a semi-finished needled felt with a unit gram weight of 600 g/m2 was prepared by using a mixture of aramid fibers as the main fibers of the filter material through the steps of opening, mixing, etc., and heat setting treatment was performed. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 20g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 2.

Comparative example 7 a semi-finished needled felt with a unit gram weight of 600 g/m2 was prepared by using a mixture of aramid fibers as the main fibers of the filter material through the steps of opening, mixing, etc., and heat setting treatment was performed. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 10g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 2.

Comparative example 8a semi-finished needled felt with a unit gram weight of 600 g/m2 was prepared by using a mixture of aramid fibers as the main fibers of the filter material through the steps of opening, mixing, etc., and heat setting treatment was performed. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 10%, the content of BHT (tertiary butyl hydroquinone) is 1.5%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 2.

Comparative example 9a semi-finished needled felt with a unit gram weight of 600 g/m2 was prepared by using a mixture of aramid fibers as the main fibers of the filter material through the steps of opening, mixing, and the like, and heat setting treatment was performed. In the preparation of the surface coating, eight carbon atom linear perfluoro and polyfluoroalkyl compounds are taken to ensure that the surface solid content is 25g, the surface solid content of the organosilicon modified acrylic ester compound is 5g, the surface solid content of the ethoxy nonionic fluorocarbon surfactant is 2.5g, the content of the silane coupling agent is 2.5%, the content of BHT (tertiary butyl hydroquinone) is 10%, and the balance is water. Spraying according to the specified spraying parameters, and then treating for 1.5 minutes at the temperature of 100 ℃ in a first area, 1.5 minutes at the temperature of 140 ℃ in a second area and 8 minutes at the temperature of 180 ℃ in a drying and shaping device. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 2.

In comparative example 10, a mixture of aramid fibers was used as the main fibers of the filter material, and a semi-finished needled felt having a unit gram weight of 600 g/m2 was produced by the steps of opening, mixing, and the like, and heat setting treatment was performed. The first zone was treated at 100℃for 1.5 minutes, the second zone was treated at 140℃for 1.5 minutes, and the third zone was treated at 180℃for 8 minutes. The filter material of the present invention is finally obtained. The physical properties of the filter material are shown in Table 2.

Table 1 physical properties of examples 1 to 16

Table 2 physical properties of comparative examples 1 to 10

From the above table, the following conclusions can be drawn:

(1) The data of examples 1-6 fully demonstrate that the performance indexes of the obtained filter materials reach the requirements of the invention within a specified range, namely, the water resistance level is 4, the oil resistance level is more than 7. After the high-temperature treatment at 240 ℃ for 24 hours, the filter material still keeps waterproof 3-4 levels and oil-proof more than 6 levels.

(2) From examples 1,2 and 3, it is evident that the ratio of the linear perfluoro and polyfluoroalkyl compounds having carbon atoms is within the preferred range under the same conditions, and the higher the adhesion ratio, the higher the water repellency and oil repellency grade of the surface coating layer.

(3) As is clear from examples 2 and 4, the water repellency and oil repellency were higher when the number of carbon atoms of the linear perfluoro and polyfluoroalkyl compounds was 8, and the number of carbon atoms was within the preferred range.

(4) Examples 2, 5, 6 and 7 show that the adhesion gram weight of the organic fluorine-silicon modified acrylic ester compound is in a preferred range, and the higher the adhesion gram weight is, the lower the concentration of the VDI outlet of the obtained filter material is, and the longer the cycle time is. When the addition ratio is too high, dust removal capacity becomes poor, dust outlet concentration is increased, circulation time is reduced, and VDI performance index is poor.

(5) From examples 2, 8, 9 and 10, it is known that the different proportions of the ethoxy nonionic fluorocarbon surfactant are added within the specified range, each performance index of the obtained filter material meets the requirements of the invention, when the adding proportion is too high, the dust removing capability is poor, the dust outlet concentration is increased, the cycle time is reduced, and the VDI performance index is poor.

(6) From examples 2, 11, 12 and 13, it is evident that the silane coupling agent is added in different proportions within the specified range, each performance index of the obtained filter material is better, and when the adding proportion is too high, the dust removing capability is poor, the dust outlet concentration is increased, the cycle time is reduced, and the VDI performance index is poor.

(7) As can be seen from examples 2 and 14, the filter materials obtained by selecting BHA (butyl hydroxy anisole) and BHT (tert-butyl hydroquinone) in the specified range have good performance indexes.

(8) From examples 2, 15 and 16, the obtained filter material has better performance indexes by adding the stabilizing agent in different proportions within a specified range, and when the adding proportion is too high, the dust removing capability is poor, the dust outlet concentration is increased, the circulation time is shortened, and the VDI performance index is poor.

(9) From example 2, comparative examples 1 and 2 show that the linear perfluoro and polyfluoroalkyl compounds having carbon atoms have excessively low adhesion gram weights, and that the water and oil repellency is satisfactory in the present invention, but the dust removal ability is poor, the dust outlet concentration is high, and the VDI performance index is poor.

(10) From example 2, comparative examples 1 and 2 show that the adhesion gram weight of the linear perfluoro and polyfluoroalkyl compounds with carbon atoms is too low, the gradient distribution adhesion proportion of the different thickness of the surface coating layer is not required, the water-repellent and oil-repellent agent capability is affected, the dust removal capability is poor, the dust outlet concentration is increased, the cycle time is shortened, and the VDI performance index is poor.

(11) From example 2, comparative examples 3 and 4 show that the organic fluorosilicone modified acrylate compound has too high gram weight, the surface coating has too high adhesion ratio in different thickness gradient distribution in partial thickness interval, the dust removing capacity is poor, the dust outlet concentration is increased, the circulation time is shortened, and the VDI performance index is poor.

(12) From example 1 and comparative example 5, it is clear that the adhesion gram weight of the organofluorosilicone modified acrylate compound is too low, the adhesion ratio of the surface coating layer in different thickness gradient distribution does not meet the requirement in a part of thickness interval, the water-repellent and oil-repellent ability is affected, the dust removal ability is poor, the dust outlet concentration is increased, and the VDI performance index is poor.

(13) From example 2 and comparative example 6, it is evident that too high an adhesion gram weight of the organofluorosilicone modified acrylate compound also makes the adhesion ratio of the surface coating layer with different thickness gradient distribution fall short of the adhesion ratio in a part of the thickness interval, and the dust removal capability is deteriorated, the dust outlet concentration is increased, and the VDI performance index is poor.

(14) From example 2, comparative examples 6,7,8 and 9, it is evident that too high gram weights of the ethoxy nonionic fluorocarbon surfactant, the silane coupling agent and the stabilizer can cause the adhesion ratio of the surface coating with different thickness gradient distribution to fall short of the requirement in a part of the thickness interval, the water-repellent and oil-repellent agent capability is affected, the dust removal capability is deteriorated, the dust outlet concentration is increased, and the VDI performance index is poor.

(15) As shown in example 4 and comparative example 10, compared with the filter material adopting the same main filter material and only adding straight-chain perfluoro and polyfluoroalkyl compounds with carbon atoms, the dust-removing filter material with anti-condensation and self-cleaning properties has better water and oil repellency retention performance after 24 hours of treatment at 240 ℃, the VDI performance outlet concentration of the filter material is 0.2-0.4mg/m ³, the outlet concentration is slightly reduced, and the VDI performance index is better.

According to the embodiment, the anti-condensation and self-cleaning dust removal filter material and the preparation method thereof can effectively improve the performance of the filter material under complex working conditions, have good comprehensive performances of anti-condensation, self-cleaning, water and oil proofing, filtering and the like, and have wide application prospects in the field of industrial dust removal. The material thought and the method of the invention have wide application scope, are not limited to industrial dust removal, can be expanded to other fields of civil wear, building protection, agricultural production and the like in the future, and have the obvious advantages and feasibility of expanding and extending to multiple fields and deeply fusing the application.

The foregoing embodiments of the present invention are merely illustrative of the present invention and are not intended to limit the scope of the present invention, and all equivalent technical solutions are also included in the scope of the present invention, which is defined by the claims.

Claims

1. The dedusting filter material with the dewing resistance and the self-cleaning performance is characterized by comprising a filter material main body and a surface treatment layer, wherein the filter material main body is a filter felt prepared by a needle punching process, the surface treatment layer at least contains one component, the component is perfluoro and polyfluoroalkyl compounds containing carbon atoms in a straight chain, the compound is uniformly covered on the surface of a fiber layer, the adhesion amount of the compound on a solid of the filter material is 5-40 g/m < 2 >, the surface treatment component is uniformly covered on the surface of the fiber at the thickness of 0-50 microns and covers at least 90% of the area of the surface of the fiber, the surface treatment component covers at least 75% of the surface of the fiber at the thickness of 50-100 microns downwards, and the surface treatment component covers less than or equal to 20% of the surface of the fiber at the thickness of less than 200 microns downwards.

2. The dust removing filter material having anti-dewing and self-cleaning properties according to claim 1, wherein the linear perfluoro and polyfluoroalkyl compounds having carbon atoms in the surface treatment layer are preferably in the form of linear or more than six carbon atoms.

3. The dedusting filter material with the anti-condensation and self-cleaning performances as claimed in claim 1, wherein the surface treatment layer further comprises an organic fluorosilicone modified acrylic ester compound, and the solid adhesion amount is 2-10 g/m ².

4. The dedusting filter material with the anti-condensation and self-cleaning performances as claimed in claim 1, wherein the surface treatment layer further comprises an ethoxy nonionic fluorocarbon surfactant, and the solid attachment amount is 1-3 g/m < 2 >.

5. The dust removing filter material with dew condensation resistance and self-cleaning performance according to claim 1, wherein the fibers forming the filter material body are one or a mixture of more of PPS fibers, aramid fibers, glass fibers, basalt fibers, polyimide and polytetrafluoroethylene.

6.A method for preparing the dust-removing filter material with anti-dewing and self-cleaning properties as claimed in any one of claims 1 to 5, characterized by comprising the steps of:

Preparing a filter material main body, namely selecting fibers and base cloth, opening, mixing, finely opening, carding, lapping, adding the base cloth and needling short fibers to prepare a semi-finished needled felt, controlling the unit gram weight to be 400-900 g/m ², and carrying out singeing, calendaring and heat setting post-treatment on the prepared filter felt according to requirements;

preparing a surface coating treatment liquid, namely preparing 5-40 g/m2 of linear perfluoro and polyfluoroalkyl compounds with carbon atoms, 2-10 g/m2 of organosilicon modified acrylic ester compounds, 1-3 g/m2 of ethoxy nonionic fluorocarbon surfactant, optionally adding a cross-linking agent, a stabilizing agent and the balance of water into the prepared treatment liquid according to the solid adhesion quality of the surface of a filter material;

and fourthly, drying and shaping the prepared filter material to improve performance stability, wherein the drying and shaping temperature is three temperature ranges, namely, one range is 80-120 ℃, the treatment time is 1-2 minutes, the second range is 120-160 ℃, the treatment time is 1-2 minutes, and the third range is 160-220 ℃ and the treatment time is 5-10 minutes.

7. The method for preparing a dust removing filter material with anti-dewing and self-cleaning properties as claimed in claim 6, wherein the cross-linking agent in the second step is preferably a silane coupling agent, the addition amount is 1-3%, the stabilizer is preferably one of Butyl Hydroxy Anisole (BHA) or BHT (tert-butyl hydroquinone), and the addition amount is 0.5-2%.

8. The dust removing filter material with anti-dewing and self-cleaning properties according to claim 1, wherein the water repellency grade and the oil repellency grade of the filter material are tested on the basis of GB/T4745-2012, the water repellency grade of the filter material is more than 4, and the oil repellency grade of the filter material is more than 7.

9. The dedusting filter material with the anti-condensation and self-cleaning performances as claimed in claim 1, wherein the filter performance of the filter material is evaluated, and the dedusting rate is more than 99.99% by adopting VDI3926-1:2004 for testing.