Preparation method of fluorine-free air filtering material and air filtering material

Abstract

The embodiment of the invention provides a preparation method of a fluorine-free air filtering material and the air filtering material.The preparation method of the fluorine-free air filtering material.The preparation method comprises the steps that glass fibers with different thicknesses are matched to serve as raw materials; the glass fibers with different thicknesses at least comprise two of coarse glass fibers, fine glass fibers and superfine glass fibers; acidic water is added into the raw materials, the raw materials and the acidic water are mixed and stirred to be dispersed into slurry, and slurry is formed; dehydrating the slurry to prepare a filter material; sizing the acrylic resin liquid diluted in proportion on the filter material to obtain an initial sample material; and drying the initial sample material to obtain the fluorine-free air filtering material. According to the fluorine-free air filtering material prepared by the method, the use of fluorine-containing materials can be effectively reduced on the premise that the filtering efficiency and the filtering precision are not changed, and the fluorine-free air filtering material plays a very important role in environmental protection.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of air filter material preparation, and particularly relates to a preparation method of fluorine-free air filter material and the air filter material. BACKGROUND

[0002] Definition (OECD): PFAS (Per-and PolyfluoroAlkyl Substances) refers to perfluoro and polyfluoro alkyl substances, which refers to organic fluorine compounds containing at least one fully fluorinated carbon atom (-CF2- or -CF3 group).

[0003] The European Union has designated strict PFAS regulation, which is banned in some fields; the PFAS list compiled by the US Environmental Protection Agency (EPA) has 14,735, and the PFAS listed in the Toxic Chemical Substance Release List TRI is 196, and the PFAS 6 categories supervised by the Drinking Water Safety Standard. Gore Tex and 3M will stop producing PFAS by the end of 2025.

[0004] PFAS is widely used, whether it is used as an air filter material or discarded, and people will directly or indirectly contact the air filter material, and when people and animals ingest PFAS, PFAS will accumulate in the body and be toxic, affect the immune system, reproductive system, interfere with the endocrine system, affect the growth and development of infants, cause liver damage, and may increase the risk of thyroid disease, kidney cancer, high blood pressure, testicular cancer and other diseases, and have potential carcinogenicity.

[0005] PFAS has also been detected in drinking water in China. A research team led by Associate Professor Huang Jun of the Environmental Simulation and Pollution Control State Key Joint Laboratory of Tsinghua University and the Beijing Key Laboratory for Emerging Organic Pollutant Control published a study in the European Environmental Science. They detected the PFAS content of 526 drinking water samples from 66 cities in China. The results were surprising, and PFAS was detected in varying degrees in these drinking water samples, with the highest concentration in Zigong, Sichuan Province, and the lowest concentration in Artux, Xinjiang Uygur Autonomous Region. Compared with other regions, the PFAS concentration in drinking water in eastern, southern and some southwestern regions of China is relatively high.

[0006] In the process of implementing the present application, the applicant found that there are at least the following problems in the prior art:

[0007] Therefore, the current problem to be solved is to prepare fluorine-free air filter material for use in the field of air filtration to solve the impact of harmful substances on humans. SUMMARY

[0008] The application provides a preparation method of fluorine-free air filtering material and the air filtering material.

[0009] To achieve the above-mentioned purpose, in one aspect, the application provides a preparation method of fluorine-free air filtering material, comprising:

[0010] Different thicknesses of glass fibers are proportioned as raw materials;

[0011] Acidic water is added to the raw materials, and the raw materials and the acidic water are mixed and stirred to be dispersed into slurry, forming a slurry;

[0012] The slurry is dehydrated to form a filter material;

[0013] The acrylic resin liquid diluted according to the proportion is applied to the filter material to obtain an initial sample;

[0014] The initial sample is dried to obtain the fluorine-free air filtering material.

[0015] In another aspect, the application provides a fluorine-free air filtering material, which is prepared according to the preparation method of the fluorine-free air filtering material, and comprises a filter material made of acidic water and glass fibers with different thicknesses, and an acrylic resin coated on the surface of the filter material.

[0016] The above technical solution has the following beneficial effects: the fluorine-free air filtering material prepared by the method has the same filtering efficiency and precision as the fluorine-containing filtering material under the premise that the filtering efficiency and precision are unchanged. The use of fluorine-containing materials can be effectively reduced, which plays a very important role in environmental protection. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0018] Figure 1 is a flow chart of the preparation method of the fluorine-free air filtering material of the application;

[0019] Figure 2 is a finished product diagram of the fluorine-free air filtering material of the application. DETAILED DESCRIPTION

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] like Figure 1 As shown, in conjunction with embodiments of the present invention, a method for preparing a fluorine-free air filter material is provided, comprising:

[0022] S101: Glass fibers of different thicknesses are mixed in proportion as raw materials;

[0023] S102: Add acidic water to the raw materials, mix and stir the raw materials and the acidic water to disperse them into a slurry, and form a slurry;

[0024] S103: The slurry is dehydrated and then made into filter material;

[0025] S104: Apply the diluted acrylic resin solution to the filter material to obtain the initial sample;

[0026] S105: The initial sample is dried to obtain a fluorine-free air filter material.

[0027] Preferably, in S101, the glass fibers of different thicknesses include at least two of the following: coarse glass fibers, fine glass fibers, and ultrafine glass fibers.

[0028] Preferably, in S102, adding acidic water to the raw material includes:

[0029] Add acidic water at a weight of 20-30 times that of the raw material to the raw material.

[0030] Preferably, the pH value of the acidic water in S102 is 2.6-3.2;

[0031] The pH value of the slurry is 2.5-3.0.

[0032] Preferably, the method for preparing the fluorine-free air filter material further includes:

[0033] S106: Mix and stir fluorine-free acrylic resin and water at a weight ratio of 1:2 to obtain a diluted acrylic resin solution.

[0034] Preferably, the method for preparing the fluorine-free air filter material further includes:

[0035] S107: Before drying the initial sample, use a vacuum pump to extract the acrylic resin liquid that is not coated on the surface of the initial sample.

[0036] Preferably, S105: The initial sample is dried to obtain a fluorine-free air filter material, comprising:

[0037] The initial sample, from which the acrylic resin liquid that was not coated on the surface of the initial sample was extracted, is dried in a drying cylinder to reduce the water content of the initial sample to less than 5%, thereby obtaining a fluorine-free air filter material.

[0038] Preferably, the initial sample, from which the acrylic resin liquid not coated on the surface of the initial sample is extracted, is dried in a drying cylinder to reduce the water content of the initial sample to less than 5%, thereby obtaining a fluorine-free air filter material, comprising:

[0039] The initial sample, from which the acrylic resin liquid not coated on the surface of the initial sample is extracted, is fed sequentially through the first, second, and third drying cylinders at a paper feeding speed of 50-80 m / min to dry the initial sample so that its moisture content is less than 5%, thus obtaining a fluorine-free air filter material. The surface temperatures of the first, second, and third drying cylinders are 60℃-90℃, 110℃-150℃, and 120℃-90℃, respectively. The corresponding drying cylinder is heated by burning natural gas in each drying cylinder.

[0040] Preferably, the surface temperatures of the first set of drying cylinders, the second set of drying cylinders, and the third set of drying cylinders are 80°C, 140°C, and 100°C, respectively.

[0041] In conjunction with embodiments of the present invention, a fluorine-free air filter material is provided. The fluorine-free air filter material is prepared according to any of the preparation methods of the fluorine-free air filter material described above. The fluorine-free air filter material includes a filter material made of acidic water and glass fibers of different thicknesses, and an acrylic resin coated on the surface of the filter material.

[0042] The technical solutions of the present invention will be described in detail below with reference to specific application examples. For technical details not described in the implementation process, please refer to the relevant descriptions above.

[0043] To address the shortcomings of existing technologies, this invention provides a process for preparing a fluorine-free air filter material (filter paper). The sequential steps of the preparation process are as follows:

[0044] a. Take raw materials by weight ratio: Glass fibers of different thicknesses are mixed in proportion according to product requirements (can be mixed by weight ratio). Add 20-30 times the weight of the raw materials to acidic water with a pH value of 2.6-3.2, mix, stir and disperse into a slurry, and ensure that the pH value of the slurry is 2.5-3.0.

[0045] The pH values ​​of the acidic water can be 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, and 3.2; the pH values ​​of the slurry can be 2.5, 2.6, 2.7, 2.8, 2.9, and 3.0.

[0046] b. The slurry is dehydrated and then made into filter media according to the existing wet forming method; wet forming refers to spreading the slurry evenly on the forming mesh (such as polyester mesh) through the headbox, and initially forming it by gravity or vacuum dehydration; adjusting the fiber orientation (random or oriented) to control the filtration directionality.

[0047] c. Apply the diluted acrylic resin solution to the surface of the filter material;

[0048] d. After removing excess acrylic resin from the filter media coated with acrylic resin solution using a vacuum pump, pass the media through three sets of drying cylinders at a speed of 50-80 m / min. The cylinders are heated by burning natural gas, and the surface temperatures of the cylinders are 60℃-90℃, 110℃-150℃, and 120℃-90℃ respectively, in order to dry the filter media so that the moisture content of the dried filter media is less than 5%.

[0049] In step a, the glass fiber is chopped glass fiber, and the weight ratio of coarse glass fiber, fine glass fiber and ultrafine glass fiber is 4:5:1.

[0050] In step c above, the acrylic resin solution is prepared by mixing 1 part by weight of fluorine-free acrylic resin and 2 parts by weight of water and stirring.

[0051] The drying cylinder temperatures in the three drying cylinders in step d above are (60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃), (110℃, 105℃, 120℃, 125℃, 130℃, 135℃, 140℃), and (120℃, 115℃, 110℃, 105℃, 100℃, 95℃, 90℃) respectively.

[0052] In this embodiment of the invention, the air filter material is guaranteed to be free of fluorine by adding fluorine-free acrylic resin.

[0053] The technical specifications of the air filter material prepared by the method of the present invention are shown in Table 1, and product images of the air filter material are shown in the figure. Figure 2 As shown.

[0054] Table 1 Comparison of performance parameters between fluorinated and non-fluorinated air filter materials

[0055]

[0056] Compared with the prior art, the beneficial technical effects achieved by the embodiments of the present invention are as follows:

[0057] The fluorine-free air filter material (filter paper) prepared by the method of this invention achieves the same filtration efficiency and precision as fluorine-containing filter materials without changing the filtration efficiency and precision. This product effectively reduces the use of fluorine-containing materials, playing a crucial role in environmental protection. It also fills the gap in the domestic filter industry for fluorine-free air filter materials, promoting the further development of the air filtration industry. Filters made from the fluorine-free air filter material prepared by this invention have obtained TUV official certification.

[0058] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0059] In the above detailed description, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features of the single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, wherein each claim stands alone as a preferred embodiment of the invention.

[0060] The disclosed embodiments have been described above to enable any person skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit and scope of this disclosure. Therefore, this disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0061] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

[0062] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a fluorine-free air filter material, characterized in that, include: Glass fibers of different thicknesses are mixed in proportion as raw materials, and the glass fibers of different thicknesses include at least two of the following: coarse glass fibers, fine glass fibers and ultrafine glass fibers. Acidic water is added to the raw materials, and the raw materials and acidic water are mixed and stirred to disperse them into a slurry, thus forming a slurry. The slurry is dehydrated and then made into filter material; Fluorine-free acrylic resin and water were mixed and stirred at a weight ratio of 1:2 to obtain a proportionally diluted fluorine-free acrylic resin solution. The proportionally diluted fluorine-free acrylic resin solution was then applied to the filter material to obtain the initial sample. The initial sample was dried to obtain a fluorine-free air filter material.

2. The method for preparing the fluorine-free air filter material according to claim 1, characterized in that, Adding acidic water to the raw materials includes: Add acidic water at a weight of 20-30 times that of the raw material to the raw material.

3. The method for preparing the fluorine-free air filter material according to claim 1, characterized in that, Adding acidic water to the raw materials includes: Acidic water with a pH of 2.6-3.2 is added to the raw materials.

4. The method for preparing the fluorine-free air filter material according to claim 1, characterized in that, The pH value of the slurry formed is 2.5-3.

0.

5. The method for preparing the fluorine-free air filter material according to claim 1, characterized in that, Also includes: Before drying the initial sample, a vacuum pump is used to extract the acrylic resin liquid that is not coated on the surface of the initial sample.

6. The method for preparing the fluorine-free air filter material according to claim 5, characterized in that, The step of drying the initial sample to obtain a fluorine-free air filter material includes: The initial sample, from which the acrylic resin liquid that was not coated on the surface of the initial sample was extracted, is dried in a drying cylinder to reduce the water content of the initial sample to less than 5%, thereby obtaining a fluorine-free air filter material.

7. The method for preparing the fluorine-free air filter material according to claim 5, characterized in that, The initial sample, from which the acrylic resin liquid not coated on the surface of the initial sample is extracted, is dried in a drying cylinder to reduce the water content of the initial sample to less than 5%, thereby obtaining a fluorine-free air filter material, comprising: The initial sample, from which the acrylic resin liquid not coated on the surface of the initial sample is extracted, is sequentially fed through the first set of drying cylinders, the second set of drying cylinders, and the third set of drying cylinders at a paper feeding speed of 50-80 m / min to dry the initial sample so that the moisture content of the initial sample is less than 5%, thereby obtaining a fluorine-free air filter material.

8. The method for preparing the fluorine-free air filter material according to claim 7, characterized in that, The surface temperatures of the first group of drying cylinders, the second group of drying cylinders, and the third group of drying cylinders are 60℃-90℃, 110℃-150℃, and 120℃-90℃, respectively. The corresponding drying cylinder is heated by burning natural gas in each group of drying cylinders.

9. The method for preparing the fluorine-free air filter material according to claim 8, characterized in that, The surface temperatures of the first set of drying cylinders, the second set of drying cylinders, and the third set of drying cylinders are 80℃, 140℃, and 100℃, respectively.

10. A fluorine-free air filter material, characterized in that, The fluorine-free air filter material is prepared by the method of preparing the fluorine-free air filter material according to any one of claims 1-9. The fluorine-free air filter material includes a filter material made of acidic water and glass fibers of different thicknesses, and an acrylic resin coated on the surface of the filter material.

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