KR20230170740A - Filter media and its manufacturing method and application - Google Patents

Abstract

The present invention relates to filter material manufacturing technology, and specifically relates to filter media, its manufacturing method, and its application. The manufacturing method includes (1) immersing the filter substrate in a metal salt solution at 55-70°C; (2) spraying a urea solution and/or aqueous ammonia solution on the surface of the filter medium after immersion, and then spraying a hydrogen peroxide solution on the surface of the filter medium; (3) It includes the step of obtaining a filter medium after heat treatment. The integrated denitrification and dust removal filter medium obtained through this method can ensure that the filter medium base and the catalyst have high binding force, and at the same time, the catalyst can be uniformly distributed on the filter medium base, and the presence of the catalyst does not affect the breathability of the filter medium. No.

Description

Filter media and its manufacturing method and application

The present invention relates to filter material manufacturing technology, and specifically to filter media, manufacturing methods and applications thereof.

Energy is an important material basis for economic and social development and improvement of living standards. With the rapid development of the economy, the demand for energy has risen rapidly in China, and highly polluting heavy industrial industries such as smelting and power generation have developed rapidly. , Most of these industries use coal as the main combustion material, causing serious smoke pollution and posing a great threat to human life and health. China has strict restrictions on smoke emissions, and the standards are becoming more stringent.

In the field of industrial smoke post-treatment, bag filters have already been widely applied in fields such as coal-fired power plants, waste incineration, and cement due to their characteristics such as high dust removal efficiency, excellent operational stability, and easy recovery. there is. Among them, filter materials such as glass fiber and PTFE are the core of bag-type dust collectors. The operating temperature (ranging from 150 to 200°C) of conventional envelope-type dust collector filter media is much lower than the temperature of catalytic reaction, which has limited the development of multifunctional filter media with a denitrification function. The denitrification and dust removal integrated filter medium is a material that blocks dust and has the function of catalytically escaping contaminants such as nitrogen oxides, sulfur oxides or heavy metals, and realizes cooperative removal of multiple contaminants, effectively avoiding the above-mentioned problems. .

Currently, the implementation form of integrated filter media for denitrification and dust removal is mainly to assemble the catalyst and filter media base by immersion or coating method. This method solves the shortcomings of low adhesion between the surface of catalyst powder and filter media base and uneven dispersion. It is difficult to do, and the service life of the filter medium and catalyst stability are insufficient. In the prior art, when manufacturing a denitrification dehydration multifunctional composite filter material, the treated metal fiber felt is immersed in a metal salt solution, and then a distal deposition agent is added to adjust the pH and sintered to obtain filtration. Although the adhesion between the catalyst and the surface of the filter material substrate is high, , the obtained filter medium has poor breathability and is prone to caking, which results in a short lifespan of the filter medium. At the same time, the problem of non-uniform dispersion of the catalyst in the filter medium substrate also occurs.

Therefore, the technical problem to be solved by the present invention is to overcome the shortcomings of the conventional technology's integrated filter media for denitrification and dust removal, which cannot simultaneously secure high binding force between the filter media and the catalyst, uniform catalyst distribution, and excellent breathability, thereby providing a filter media and a method of manufacturing the same. Provides its application.

Accordingly, the present invention provides the following technical solution.

The present invention provides a method for producing a filter medium, the method comprising:

(1) immersing the filter material substrate in a metal salt solution at 55-70°C;

(2) spraying a urea solution and/or ammonia water solution on the surface of the filter medium after immersion, and then spraying a hydrogen peroxide solution on the surface of the filter medium;

(3) It includes the step of obtaining a filter medium after heat treatment.

The mass concentration of the urea solution is 5 - 40%;

The volume concentration of the aqueous ammonia solution is 35 - 60%;

The volume concentration of hydrogen peroxide is 10 - 45%.

In step (2), a urea solution and/or aqueous ammonia solution is sprayed on the surface of the filter medium base under conditions of 55 - 80°C, and a hydrogen peroxide solution is sprayed on the surface of the filter medium base under conditions of 55 - 80°C;

Based on the filter material substrate per square meter, the spray amount of aqueous ammonia solution is 150 - 330 ml/m ² ;

Based on the filter substrate per square meter, the spray amount of urea solution is 150 - 230 ml/m ² ;

Based on the filter substrate per square meter, the spray amount of hydrogen peroxide solution is 120 - 300 ml/m ² .

In step (1), the time for immersing the filter material substrate in the metal salt solution exceeds 30 s;

The metal salt solution includes at least one of titanium salt, cerium salt, and manganese salt;

The mass concentration of the metal salt solution is 30 - 35%.

The metal salt solution includes titanium salt, cerium salt, and manganese salt;

The molar ratio of titanium, cerium and manganese in the metal salt solution is (10 - 12): (0.7 - 1.3): (4 - 5).

The temperature of the heat treatment is 250 - 300 ° C, and the time is 20 - 30 min.

After the heat treatment step, a polytetrafluoroethylene composite emulsion is sprayed on the surface of the filter substrate, sintered, and then heat-compressed and coated with a polytetrafluoroethylene expanded microporous membrane. It further includes steps.

The process parameters of the thermocompression coating include a temperature of 260 - 380° C., a speed of 1 - 10 m/min, and a pressure of 0.2 - 0.5 MPa;

The polytetrafluoroethylene composite emulsion is a polytetrafluoroethylene emulsion with a mass ratio of (20 - 50): (10 - 20): (0.5 - 1.5): (1.5 - 5), a fluorine-containing silane waterproofing agent (fluorine-containing silane waterproofing agent), coupling agent and inorganic waterproofing agent;

The temperature of the sintering is 260 - 320 ° C, and the sintering time is 4 - 10 min.

further comprising a drying step between the heat treatment and the polytetrafluoroethylene composite emulsion spraying step; Here, the drying temperature is 100 - 120 ℃.

The present invention further provides a filter medium obtained by manufacturing by the above-described method.

The filter medium is a filter medium that integrates dust removal and denitration, and can simultaneously serve the functions of dust removal and denitration.

In addition, the present invention further provides the filter medium produced by the above-described method or the application of the above-described filter medium in catalytic denitrification.

The technical solution of the present invention has the following advantages.

1. The present invention provides a method for producing a filter medium, the method comprising: (1) immersing the filter medium substrate in a metal salt solution at 55-70°C; (2) spraying a urea solution and/or aqueous ammonia solution on the surface of the filter medium after immersion, and then spraying a hydrogen peroxide solution on the surface of the filter medium; (3) It includes the step of obtaining a filter medium after heat treatment. The integrated denitrification and dust removal filter medium obtained through this method can secure high binding force between the filter medium base and the catalyst, while also allowing the catalyst to be uniformly distributed over the filter medium base, and the presence of the catalyst does not affect the breathability of the filter medium. . The filter material substrate is immersed in the metal salt solution under conditions of 55 - 70 ℃, while ensuring a uniform state of the metal solution, so that the metal ions are uniformly loaded on the surface layer of the fibers of the filter material substrate, and urea and/or ammonia water are added. After addition, when the catalyst is formed on the surface layer of the filter material base fiber, the catalyst particles will not block the filter material pores and will not affect the breathability of the filter material; On the other hand, at that temperature, the metal salt solution exhibits a stable state, so that no suspension is formed and has excellent permeability to the filter medium substrate, allowing the metal salt solution to uniformly coat the filter medium substrate, and the filter medium substrate has excellent permeability. have The urea solution and/or ammonia water solution is sprayed onto the surface of the filter medium substrate using a spraying method, and the urea and/or ammonia water reacts with the metal ions on the surface layer of the filter medium substrate to form catalyst particles on the surface layer of the filter medium substrate. ensures that it is firmly attached to the surface of the filter medium and has strong binding force; Compared to the direct immersion method used in the prior art, the spraying method used in the present invention has a small effect on the breathability of the filter medium and the catalytic denitrification efficiency, and generates catalyst particles on the surface layer of the filter medium, causing the particles inside the filter medium to block the pores and the filter medium. It reduces caking and improves filtration efficiency and service life.

Spraying urea solution and/or aqueous ammonia solution has excellent reduction effect and has a wide range of sources, so it can be widely applied to remove nitrogen oxides from industrial smoke.

By spraying a hydrogen peroxide solution onto the filter substrate using a spraying method, the stability of the valence state of the metal ion in the metal complex can be further improved, the catalytic denitrification efficiency is improved, and other metal ions are not introduced during use. It does not affect the stability of the catalyst system, is inexpensive, and has no pollution.

The method for producing a filter material provided by the present invention is applied to heat-resistant filter material substrates such as glass fiber, polytetrafluoroethylene, polyimide, aramid fiber, and metal fiber.

2. In the method for producing a filter medium provided by the present invention, the present invention sprays a reducing agent and an oxidizing agent on the surface of the filter medium substrate under conditions of 55 - 80 ° C. to prevent precipitation and precipitation of metal ions in the metal salt solution. When the metal salt solution reacts with the reducing agent, the problem of aggregation does not occur, and by allowing the metal salt solution to sufficiently contact and react with the reducing agent and the oxidizing agent, an integrated filter medium with uniform distribution of the catalyst is obtained.

3. In the method for producing a filter medium provided by the present invention, the metal salt solution in the method includes titanium salt, cerium salt and manganese salt, on the one hand, the catalytic efficiency of the catalyst can be improved, and on the other hand, the filter medium can be When used for catalytic denitrification, the reaction temperature can be lowered.

By controlling the heat treatment temperature to 250 - 280 ℃, a filter medium with integrated dust removal and denitrification can be manufactured and the heat treatment temperature is lowered, saving energy and being environmentally friendly.

In order to more clearly explain the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings necessary for use of the specific embodiments or the prior art will be briefly described below, and the accompanying drawings described below are some embodiments of the present invention. It is obvious to those skilled in the art that other drawings can be obtained based on these drawings under the premise that no creative labor is involved.
Figure 1 is a scanning electron microscope photograph of the filter medium in Example 1 of the present invention.

The following examples are provided to more clearly understand the present invention, and are not limited to these optimal embodiments, nor do they limit the content and claims of the present invention, and do not allow anyone to suggest or differ from the present invention. Any product that is the same or similar to the present invention that can be obtained by combining the features of the prior art falls within the scope of the claims of the present invention.

If specific experimental steps and conditions are not specified in the examples, the procedure can be carried out by referring to the operations or conditions of typical experimental steps described in the literature in the present technical field. The prototype or device used may be any commercial prototype available for purchase, unless the manufacturer is specified.

The coupling agent used in the comparative examples in the following examples is KH1100, the fluorine-containing silane waterproofing agent is FLW-99 type, and the inorganic waterproofing agent is a nano-inorganic silicone waterproofing agent.

Example 1

This embodiment provides a method for producing a filter medium, and the method includes the following steps.

(1) Under conditions of 65°C, a glass fiber substrate is immersed in a metal salt solution, and the immersion time is 1 min; Here, the metal salt solution includes titanyl oxide sulfate, cerium nitrate, and manganese acetate at a molar ratio of 11:1:4.5, and the mass concentration of the metal salt solution is 15 wt%.

(2) The glass fiber substrate is then placed in an atmosphere at 65°C, and an aqueous ammonia solution with a volume concentration of 40% and a hydrogen peroxide solution with a volume concentration of 30% are sequentially sprayed on the surface of the immersed glass fiber substrate, based on the filter material substrate per square meter. , the spray amount of the ammonia solution is 220 ml/m ² and the spray amount of the hydrogen peroxide solution is 160 ml/m ² , and after completion of spraying, the glass fiber substrate is dried under conditions of 120° C. to remove liquid such as excess moisture.

(3) After drying the glass fiber substrate at 300°C and heat treating it for 20 minutes, a layer of polytetrafluoroethylene composite emulsion is sprayed on the surface, sintered at 300°C for 7 minutes, and polytetrafluoroethylene expanded microporous After covering the membrane and thermocompression, the filter medium is obtained. Here, the polytetrafluoroethylene composite emulsion includes a polytetrafluoroethylene emulsion with a mass ratio of 45:15:1.5:1.5:37, a fluorine-containing silane waterproofing agent, a coupling agent, an inorganic waterproofing agent, and water, and the spray amount is based on the glass fiber base. It is 4% of the mass; The temperature of the thermocompression coating is 345°C, the pressure is 0.3 MPa, and the speed is 4m/min.

Figure 1 is a schematic diagram of the filter medium of this example, and it can be seen from the figure that the catalyst was uniformly distributed on the surface of the filter medium substrate.

Example 2

This embodiment provides a method for producing a filter medium, and the method includes the following steps.

(1) Under conditions of 60°C, the polyimide needle felt substrate is immersed in the metal salt solution, and the immersion time is 1.5 min; Here, the metal salt solution includes titanyl oxide sulfate, cerium nitrate, and manganese acetate at a molar ratio of 11:1:4.5, and the concentration of the metal salt solution is 10 wt%.

(2) Afterwards, the polyimide punch felt base material is placed in an atmosphere at 70°C, and an aqueous solution of urea with a mass concentration of 40% and a hydrogen peroxide solution with a volume concentration of 12% are sequentially sprayed on the surface of the immersed polyimide punch felt base material, at a rate per square meter. Based on the filter material base, the spray amount of the urea aqueous solution is 200 ml/m ² and the spray amount of the hydrogen peroxide solution is 140 ml/m ^2. After spraying, the polyimide punch felt base material is dried under conditions of 120°C to remove excess water. Remove liquids such as moisture.

(3) After drying the polyimide punch felt base material at 260°C and heat treating it for 25 minutes, a layer of polytetrafluoroethylene composite emulsion is sprayed on the surface and heat-treated at 280°C for 10 minutes to expand the polytetrafluoroethylene. A filter medium is obtained after coating with a microporous membrane and thermocompression. Here, the polytetrafluoroethylene composite emulsion includes a polytetrafluoroethylene emulsion with a mass ratio of 40:15:1:2:42, a fluorine-containing silane waterproofing agent, a coupling agent, an inorganic waterproofing agent, and water, and the injection amount is polyimide punch. 4 wt% of the mass of the felt substrate; The temperature of the thermocompression coating is 328°C, the pressure is 0.45 MPa, and the speed is 5 m/min.

Example 3

This embodiment provides a method for producing a filter medium, and the method includes the following steps.

(1) Under the condition of 70°C, the glass fiber and polyimide composite punch felt substrate is immersed in the metal salt solution, and the immersion time is 0.8 min; Here, the metal salt solution includes titanyl oxide sulfate, cerium nitrate, and manganese acetate at a molar ratio of 11:1:4.5, and the concentration of the metal salt solution is 35 wt%.

(2) After that, the composite punch felt substrate is placed in an atmosphere at 70°C, and an aqueous ammonia solution with a volume concentration of 40% and a hydrogen peroxide solution with a volume concentration of 40% are sequentially sprayed on the surface of the composite punch felt substrate after immersion, and the filter material substrate is applied per square meter. As a standard, the spray amount of the ammonia solution is 320 ml/m ² and the spray amount of the hydrogen peroxide solution is 270 ml/m ^2. After the spray is completed, the composite punch felt base material is dried under conditions of 120°C to remove excess moisture and other liquid. Remove.

(3) After drying the composite punch felt substrate at 280°C and heat treating it for 20 minutes, a layer of polytetrafluoroethylene composite emulsion is sprayed on the surface, sintered at 380°C for 25 minutes, and polytetrafluoroethylene puffing micro-emulsion is applied. A filter medium is obtained after coating with a porous membrane and thermocompression. Here, the polytetrafluoroethylene composite emulsion includes a polytetrafluoroethylene emulsion with a mass ratio of 50:10:1.5:1.5:37, a fluorine-containing silane waterproofing agent, a coupling agent, an inorganic waterproofing agent, and water, and the spray amount is based on the composite punch felt base material. 4 wt% of the mass; The temperature of the thermocompression coating is 320°C, the pressure is 0.5 MPa, and the speed is 10 m/min.

Example 4

This embodiment provides a method for producing a filter medium, and the method includes the following steps.

(1) Under the condition of 55°C, the glass fiber substrate is immersed in the metal salt solution, and the immersion time is 1.5 min; Here, the metal salt solution includes titanyl oxide sulfate, cerium nitrate, and manganese acetate at a molar ratio of 11:1:4.5, and the concentration of the metal salt solution is 10 wt%.

(2) The glass fiber substrate is then placed in an atmosphere at 60°C, and an aqueous ammonia solution with a volume concentration of 35% and a hydrogen peroxide solution with a volume concentration of 20% are sequentially sprayed on the surface of the immersed glass fiber substrate, based on the filter material substrate per square meter. , the spray amount of the ammonia solution is 160 ml/m ² and the spray amount of the hydrogen peroxide solution is 120 ml/m ² , and after completion of spraying, the glass fiber substrate is dried under conditions of 120° C. to remove liquid such as excess moisture.

(3) The dried glass fiber substrate is heat treated at 250°C for 20 minutes, then a layer of polytetrafluoroethylene composite emulsion is sprayed on the surface, sintered at 300°C for 4 minutes, and a polytetrafluoroethylene expanded microporous membrane is formed. After heat compression and coating, the filter material is obtained. Here, the polytetrafluoroethylene composite emulsion includes a polytetrafluoroethylene emulsion with a mass ratio of 50:10:1:2:36, a fluorine-containing silane waterproofing agent, a coupling agent, an inorganic waterproofing agent, and water, and the spray amount is based on the glass fiber base. 4 wt% of the mass; The temperature of the thermocompression coating is 340°C, the pressure is 0.35 MPa, and the speed is 6 m/min.

Comparative Example 1

This comparative example provides a method for producing a filter medium, and the method includes the following steps.

(1) Under the condition of 80°C, the glass fiber substrate is immersed in the metal salt solution, and the immersion time is 1 min; Here, the metal salt solution includes titanyl oxide sulfate, cerium nitrate, and manganese acetate at a molar ratio of 11:1:4.5, and the concentration of the metal salt solution is 15 wt%.

(2) Afterwards, the glass fiber substrate is placed in an atmosphere at 70°C, and an ammonia solution with a volume concentration of 40% and a hydrogen peroxide solution with a volume concentration of 30% are sequentially sprayed on the surface of the immersed glass fiber substrate, based on the filter material substrate per square meter. , the spray amount of the ammonia solution is 220 ml/m ² and the spray amount of the hydrogen peroxide solution is 160 ml/m ² , and after completion of spraying, the glass fiber substrate is dried under conditions of 120° C. to remove liquid such as excess moisture.

(3) The dried glass fiber substrate is heat treated at 280°C for 20 minutes, then a layer of polytetrafluoroethylene composite emulsion is sprayed on the surface, sintered at 300°C for 20 minutes, and a polytetrafluoroethylene expanded microporous membrane is formed. After heat compression and coating, the filter material is obtained. Here, the polytetrafluoroethylene composite emulsion includes a polytetrafluoroethylene emulsion with a mass ratio of 45:15:1.5:1.5:37, a fluorine-containing silane waterproofing agent, a coupling agent, an inorganic waterproofing agent, and water, and the spray amount is based on the glass fiber base. 4 wt% of the mass; The temperature of the thermocompression coating is 345°C, the pressure is 0.3 MPa, and the speed is 4 m/min.

Comparative Example 2

This comparative example provides a method for producing a filter medium, and the method includes the following steps.

(1) Under conditions of 65°C, the glass fiber substrate is immersed in the metal salt solution, and an aqueous ammonia solution is added to adjust the pH of the metal salt solution to 9 - 10. The filter material substrate is taken out and placed in the reactor, and reacted at 60°C for 1 hour. After drying, excess moisture and other liquid are removed. Here, the metal salt solution includes titanyl oxide sulfate, cerium nitrate, and manganese acetate at a molar ratio of 11:1:4.5, and the mass concentration of the metal salt solution is 15 wt%.

(2) The dried glass fiber substrate is heat-treated at 280°C for 20 minutes, then a layer of polytetrafluoroethylene composite emulsion is sprayed on the surface, sintered at 300°C for 7 minutes, and a polytetrafluoroethylene-bulged microporous membrane is formed. After heat compression and coating, the filter material is obtained. Here, the polytetrafluoroethylene composite emulsion includes a polytetrafluoroethylene emulsion with a mass ratio of 45:15:1.5:1.5:37, a fluorine-containing silane waterproofing agent, a coupling agent, an inorganic waterproofing agent, and water, and the spray amount is based on the glass fiber base. 4 wt% of the mass; The temperature of the thermocompression coating is 345°C, the pressure is 0.3 MPa, and the speed is 4 m/min.

Experiment example

This experimental example provides performance tests and test results of the filter media prepared in Examples 1 to 4 and Comparative Examples 1 to 2, the test method is as follows, and the test results are listed in Table 1.

Filter media catalyst loading square meter gram deviation is in accordance with the standard GB/T6719 - 2009c clause 9.1;

The breathability of the filter media is in accordance with the standard GB/T6719 - 2009c section 9.2;

The filtration resistance of the filter medium is in accordance with section 9.5 of the standard GB/T6719 - 2009c.

The test method for filter media catalyst denitrification efficiency is as follows. The denitrification efficiency is tested at 250°C, and specifically, the nitrogen oxide-containing gas is passed through a disk-shaped filter medium with a diameter of 10 cm at a speed of 0.5 m/min, and then the percent reduction in nitrogen oxide concentration is measured.

Performance test results of filter media example breathable
(cm/s) Catalyst Loading Square Meter Grams Deviation (%) Catalytic denitrification efficiency (%) filtration resistance
(Pa) Example 1 3.63 6.5 65.4 180 Example 2 3.64 6.8 66.3 176 Example 3 3.52 7.1 65.1 187 Example 4 3.41 6.4 67.6 194 Comparative Example 1 2.73 9.3 56.2 243 Comparative Example 2 2.07 12.4 42.7 308

As can be seen from Table 1, the deviation of the square meter gram number of catalyst loading obtained by manufacturing in the present invention is small, which explains that the catalyst is uniformly distributed on the filter medium substrate, and the efficiency of using the filter medium for denitrification and denitrification is high; The smaller the filtration resistance, the greater the breathability, which explains the better breathability of the filter medium. In addition, during application, the inventors discovered that the filter medium with both dust removal and catalytic denitrification functions obtained by manufacturing in Examples 1 to 4 of the present invention. It is not easily detached during the use process, but the filter media prepared in Comparative Examples 1-2 experienced a detachment phenomenon of varying degrees during use, so the binding power of the filter medium and the catalyst obtained by manufacturing in the present invention was higher, and the binding power was higher. On the basis of ensuring catalyst distribution uniformity and breathability were further improved.

Of course, the above-described embodiment is only an example for clear explanation and is not intended to limit the embodiment. For those skilled in the art, other changes or modifications may be made based on the above description. There is no need for an endless listing of all embodiments herein. Any obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims (10)

In the method of manufacturing a filter medium,
(1) immersing the filter material substrate in a metal salt solution at 55-70°C;
(2) spraying a urea solution and/or aqueous ammonia solution on the surface of the filter medium after immersion, and then spraying a hydrogen peroxide solution on the surface of the filter medium;
(3) A method for producing a filter medium, comprising the step of obtaining the filter medium after heat treatment.
According to paragraph 1,
The mass concentration of the urea solution is 5 - 40%;
The volume concentration of the aqueous ammonia solution is 35 - 60%;
A production method, characterized in that the volume concentration of hydrogen peroxide is 10-45%.
According to claim 1 or 2,
In step (2), a urea solution and/or aqueous ammonia solution is sprayed on the surface of the filter medium base under conditions of 55 - 80°C, and a hydrogen peroxide solution is sprayed on the surface of the filter medium base under conditions of 55 - 80°C;
Based on the filter material substrate per square meter, the spray amount of aqueous ammonia solution is 150 - 330 ml/m ² ;
The spray amount of urea solution is 150 - 230 ml/m ² ;
A manufacturing method characterized in that the spray amount of hydrogen peroxide solution is 120 - 300 ml/m ² .
According to any one of claims 1 to 3,
In step (1), the time for immersing the filter material substrate in the metal salt solution exceeds 30 s;
The metal salt solution includes at least one of titanium salt, cerium salt, and manganese salt;
A production method, characterized in that the mass concentration of the metal salt solution is 30-35%.
According to paragraph 4,
The metal salt solution includes titanium salt, cerium salt and manganese salt;
A manufacturing method, characterized in that the molar ratio of titanium, cerium and manganese in the metal salt solution is (10 - 12): (0.7 - 1.3): (4 - 5).
According to any one of claims 1 to 5,
A manufacturing method characterized in that the temperature of the heat treatment is 250 - 300 ° C, and the time is 20 - 30 min.
According to any one of claims 1 to 6,
After the heat treatment step, spraying a polytetrafluoroethylene composite emulsion on the surface of the filter substrate, sintering, and then heat-compressing and coating with a polytetrafluoroethylene puffed microporous membrane. method.
In clause 7,
The process parameters of the thermocompression coating include a temperature of 260 - 380° C., a speed of 1 - 10 m/min, and a pressure of 0.2 - 0.5 MPa;
The polytetrafluoroethylene composite emulsion is a polytetrafluoroethylene emulsion with a mass ratio of (20 - 50): (10 - 20): (0.5 - 1.5): (1.5 - 5), a fluorine group-containing silane waterproofing agent, a coupling agent, and Contains an inorganic water repellant;
A manufacturing method characterized in that the sintering temperature is 260 - 320 ° C, and the sintering time is 4 - 10 min.
A filter medium obtained by manufacturing by the method according to any one of claims 1 to 8.
Application of the filter medium obtained by manufacturing by the method according to any one of claims 1 to 8 or the filter medium according to claim 9 in catalytic denitrification.