Multi-interface dielectric filter material with woven structure and application of multi-interface dielectric filter material

Abstract

The invention belongs to the technical field of air filter materials, and discloses a multi-interface dielectric filter material with a woven structure and application thereof, the multi-interface dielectric filter material is composed of a fabric substrate and a dielectric enhancement layer attached to the surface of the fabric substrate; the fabric substrate comprises two layers of mesh surfaces and connecting monofilaments for connecting the two layers of mesh surfaces; the dielectric enhancement layer includes a base material and a solvent. The multi-interface dielectric filter material has a super-loose structure, and can be repeatedly cleaned to remove accumulated dust in the filter material, prolong the service life of the filter material, reduce the replacement frequency of the filter material and reduce the maintenance cost of a user; and the filter material with the ultra-loose structure can simultaneously realize ultra-low filter resistance, reduce energy consumption and reduce the use cost of a user.

Description

Technical Field

[0001] The invention relates to the technical field of air filter materials, and in particular to a multi-interface dielectric filter material with a woven structure and application thereof. Background Art

[0002] The presence of particulate pollutants in the air may cause respiratory diseases such as asthma and chronic obstructive pulmonary disease, and may aggravate the development of cardiovascular diseases, posing a great threat to human health. Traditional air filtration technology is mainly based on mechanical filtration, and its filtration efficiency is directly affected by the stacking density and thickness of the filter material fibers. It usually has a large filtration resistance and cannot meet the needs of high-throughput and low-energy filtration. To solve the above problems, researchers have proposed a filtration technology with low filtration resistance based on electrostatic action, including electret filters and electrostatic precipitators. Among them, the storage charge of the electret filter is limited, and the charge will decay with use, resulting in poor stability of the filtration efficiency. The filter material structure of the electret filter is mostly electrospun nanofibers or non-woven structures, which have limited strength, and generally have a dense structure and large filtration resistance. The electrostatic precipitator system not only has a low single-time collection efficiency for submicron fine particles, but is also prone to secondary dust.

[0003] To solve the above problems, researchers have developed active electrostatically assisted air filters and electric bag composite dust collectors. Among them, the active electrostatically assisted air filter, as a new type of filter, combines the active characteristics of the electrostatic precipitator with the textile material base characteristics of the electret filter material, thereby greatly improving the stability of the filter material charge load, and the charge will not dissipate due to the gradual use of the air filter. The electric bag composite dust collector is similar to the active electrostatically assisted air filter, using the principles of electrostatic precipitators and bag dust removal, but due to the dense structure of the bag, its filtration resistance is higher than that of the active electrostatically assisted air filter. In this regard, the patent (CN216094257U) uses a wavy dielectric material filter placed in a polarized electric field for filtering, but the filter is a HEPA filter with large filtration resistance, without any treatment to improve dielectric properties, and a high polarization voltage; the patent (CN107570323A) uses foam and non-woven filters, and carries dielectric particles to improve the dielectric constant, thereby improving the filtration efficiency of particulate matter and reducing the polarization voltage, but the foam or non-woven structure of the filter has poor mechanical properties and is easy to accumulate dust and difficult to clean. After long-term use and repeated cleaning, it is not only difficult to maintain the original shape and mechanical properties, but also leads to reduced filtration efficiency, and dust accumulation gradually increases the pressure drop, and it is impossible to restore the filtration resistance close to the initial level.

[0004] Therefore, it is of great significance to study and obtain a multi-interface dielectric filter material with a woven structure having a loose structure and excellent mechanical properties, so that it can be combined with an active electrostatic assisted filter to achieve a high-efficiency, low-resistance filtering effect and a washable effect. Summary of the invention

[0005] In view of this, the present invention provides a multi-interface dielectric filter material with a woven structure and its application, the purpose of which is to solve the problems of low filtration efficiency, poor mechanical properties, easy dust accumulation and inability to clean existing in the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] The present invention provides a multi-interface dielectric filter material with a woven structure, wherein the multi-interface dielectric filter material is composed of a fabric base and a dielectric reinforcement layer attached to the surface of the fabric base;

[0008] The fabric base comprises two layers of mesh surfaces and connecting monofilaments connecting the two layers of mesh surfaces;

[0009] The dielectric reinforcement layer includes a matrix material and a solvent.

[0010] Preferably, the fabric base is made of high dielectric yarns through integrated weaving;

[0011] The high dielectric yarn is one or more of polyester fiber yarn, polytetrafluoroethylene yarn, polyvinylidene fluoride yarn, polyurethane yarn, polypropylene yarn, polystyrene yarn and polyimide yarn.

[0012] Preferably, the structure of the high dielectric yarn includes monofilament yarn, multifilament yarn, composite twisted yarn, twisted spun yarn, textured yarn or core-spun yarn;

[0013] The structure of the mesh surface includes a two-dimensional grid structure, a warp knitting structure, a warp knitting 2.5-dimensional corner interlocking structure, a three-dimensional woven structure or a three-dimensional warp knitting structure.

[0014] Preferably, the thickness of the fabric base is 0.1 to 5 cm, and the pore size of the mesh surface is 0.1 to 10 mm.

[0015] Preferably, the dielectric enhancement layer comprises a matrix material, dielectric particles and a solvent.

[0016] Preferably, the matrix material is one or more of polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride, thermoplastic polyurethane, polydopamine, polyacrylonitrile, polyvinyl pyridone, polystyrene, polyvinyl alcohol, polypropylene, polyamide-6 and polyurethane.

[0017] Preferably, the dielectric particles are one or more of barium titanate, barium strontium titanate, lead zirconate titanate, calcium copper titanate, manganese dioxide, activated carbon, zinc oxide and copper oxide;

[0018] The solvent is one or more of dimethylformamide, tetrahydrofuran, acetone, tetramethylurea, dimethyl sulfoxide, trimethyl phosphate and N-methylpyrrolidone.

[0019] Preferably, the number of dielectric reinforcement layers is 1 to 10, and the total thickness of the dielectric reinforcement layers is 0.1 to 100 μm.

[0020] Preferably, the attachment method is one or more of a dipping method, a coating method, a thermal bonding method and a melting method.

[0021] The invention also provides an application of a multi-interface dielectric filter material with a woven structure in air filtration.

[0022] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0023] The multi-interface dielectric filter material of the present invention can be placed in an electric field to achieve polarization and charge loading; it is composed of high dielectric materials, so that the polarization effect of the dielectric material itself and the polarization effect between the interfaces of different materials can be generated in the electric field, and the filter material polarizes more charges to achieve higher filtering efficiency.

[0024] The multi-interface dielectric filter material of the present invention has high dielectric and high electricity storage properties, and can cooperate with an active electrostatic assisted filter to achieve high-efficiency filtering performance. At the same time, due to its ultra-loose woven structure and excellent mechanical properties, the filter material has the characteristics of ultra-low filtration resistance, low energy consumption, and washability.

[0025] The multi-interface dielectric filter material of the present invention can be repeatedly cleaned to remove dust accumulated in the filter material due to its ultra-loose structure, thereby extending the life of the filter material and reducing the number of times the filter material is replaced. At the same time, the ultra-loose structure of the filter material can achieve ultra-low filtration resistance, reduce energy consumption, and reduce user costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0027] Figure 1 The structure schematic diagram of the multi-interface dielectric filter material obtained by the present invention, wherein 1 is the mesh surface with the dielectric reinforcement layer attached, 2 is the connecting monofilament with the dielectric reinforcement layer attached, and 3 is the mesh surface with the dielectric reinforcement layer attached;

[0028] Figure 2 The multi-interface dielectric filter material obtained in Example 1 is Figure 1The enlarged view of the fiber cross section at X in the middle, where 4 is the dielectric reinforcement layer attached to the surface of the connecting monofilament, and 5 is the connecting monofilament;

[0029] Figure 3 The multi-interface dielectric filter material obtained in Example 1 is Figure 1 The enlarged view at Y in the middle, wherein 6 is the dielectric reinforcement layer attached to the mesh surface, and 7 is the mesh surface;

[0030] Figure 4 The multi-interface dielectric filter material obtained in Example 2 is Figure 1 The enlarged view of the fiber cross section at X in the middle, wherein 8 is the dielectric reinforcement layer attached to the surface of the connecting monofilament, and 9 is the connecting monofilament;

[0031] Figure 5 The multi-interface dielectric filter material obtained in Example 2 is Figure 1 The enlarged view at point Y in the middle, wherein 10 is the dielectric reinforcement layer attached to the mesh surface, and 11 is the mesh surface. DETAILED DESCRIPTION

[0032] The present invention provides a multi-interface dielectric filter material with a woven structure, wherein the multi-interface dielectric filter material is composed of a fabric base and a dielectric reinforcement layer attached to the surface of the fabric base;

[0033] The fabric base comprises two layers of mesh surfaces and connecting monofilaments connecting the two layers of mesh surfaces;

[0034] The dielectric reinforcement layer includes a matrix material and a solvent.

[0035] In the present invention, the fabric base is made of high dielectric yarns through integrated weaving;

[0036] The high dielectric yarn is preferably one or more of polyester yarn, polytetrafluoroethylene yarn, polyvinylidene fluoride yarn, polyurethane yarn, polypropylene yarn, polystyrene yarn and polyimide yarn.

[0037] In the present invention, the diameter of the high dielectric yarn is preferably 0.1 to 2 mm, more preferably 0.4 to 1.6 mm, and even more preferably 0.8 to 1.2 mm.

[0038] In the present invention, the structure of the high dielectric yarn includes monofilament yarn, multifilament yarn, composite twisted yarn, twisted spun yarn, textured yarn or core-spun yarn;

[0039] The structure of the mesh surface includes a two-dimensional grid structure, a warp knitting structure, a warp knitting 2.5-dimensional corner interlocking structure, a three-dimensional woven structure or a three-dimensional warp knitting structure.

[0040] In the present invention, the thickness of the fabric base is preferably 0.1 to 5 cm, more preferably 1.5 to 4 cm, more preferably 2 to 3.5 cm, and the pore size of the mesh surface is preferably 0.1 to 10 mm, more preferably 2 to 8 mm, more preferably 4 to 6 mm.

[0041] In the present invention, the fabric substrate has excellent mechanical properties and a long service life. After long-term use or repeated cleaning, it can still maintain its original shape and mechanical properties. The excellent mechanical properties also enable the filter material to withstand higher pressure and be used under higher wind speed conditions to achieve higher purification flux.

[0042] In the present invention, the dielectric enhancement layer comprises a matrix material, dielectric particles and a solvent.

[0043] In the present invention, the base material is used to improve the dielectric properties of the fabric substrate. The multi-layer design of the dielectric reinforcement layer and the addition of dielectric particles form a multi-interface structure, which can form more charge storage under the polarization electric field in the same space.

[0044] In the present invention, the matrix material is preferably one or more of polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride, thermoplastic polyurethane, polydopamine, polyacrylonitrile, polyvinyl pyridone, polystyrene, polyvinyl alcohol, polypropylene, polyamide-6 and polyurethane.

[0045] In the present invention, the dielectric particles are preferably one or more of barium titanate, barium strontium titanate, lead zirconate titanate, calcium copper titanate, manganese dioxide, activated carbon, zinc oxide and copper oxide;

[0046] The solvent is preferably one or more of dimethylformamide, tetrahydrofuran, acetone, tetramethylurea, dimethyl sulfoxide, trimethyl phosphate and N-methylpyrrolidone.

[0047] In the present invention, the number of dielectric reinforcement layers is preferably 1 to 10, more preferably 4 to 8, and more preferably 5 to 6. The total thickness of the dielectric reinforcement layers is preferably 0.1 to 100 μm, more preferably 20 to 80 μm, and more preferably 40 to 60 μm.

[0048] In the present invention, the preparation method of the solution of the dielectric reinforcement layer is to first mix the base material and the solvent, then add the dielectric particles and stir to obtain the solution of the dielectric reinforcement layer; the mixing temperature is preferably 20-30°C, more preferably 24-28°C, more preferably 25-26°C, the mixing time is preferably 0.5-5min, more preferably 1-4min, more preferably 2-3min, the stirring time is preferably 50-70min, more preferably 55-65min, more preferably 58-60min, and the stirring temperature is preferably 50-60°C, more preferably 52-58°C, more preferably 54-56°C.

[0049] In the present invention, the dielectric reinforcement layer only covers the surface of the mesh and the surface of the connecting monofilaments, and will not block the airflow through the mesh. The base fabric itself has excellent dielectric properties. The addition of the functional layer increases the polarization part, and at the same time, the interface polarization effect occurs, which increases the electrical storage performance of the filter material and greatly enhances the filtering effect.

[0050] In the present invention, the attachment method is preferably one or more of a dipping method, a coating method, a thermal bonding method and a melting method.

[0051] The invention also provides an application of a multi-interface dielectric filter material with a woven structure in air filtration.

[0052] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0053] Example 1

[0054] The multi-interface dielectric filter material in this embodiment includes a fabric substrate and a dielectric reinforcement layer:

[0055] Fabric base: two layers of mesh (the mesh aperture is evenly distributed between 0.3 and 8 mm), the surface is a three-dimensional warp-knitted hexagonal hollow structure polyester fiber fabric, and the connecting monofilament is a polyester fiber monofilament;

[0056] Dielectric reinforcement layer: The base material is polyvinylidene fluoride and the solvent is dimethylformamide.

[0057] The preparation steps are as follows:

[0058] The 60D polyester fiber monofilament is integrated and woven to obtain a fabric base with a thickness of 1 cm. The square meter weight of the obtained fabric base is 655 g / m 2 ;

[0059] Mixing polyvinylidene fluoride and dimethylformamide at a mass ratio of 5:100 at 60° C. for 0.5 min to obtain a dielectric reinforcement layer solution;

[0060] The fabric substrate was immersed in a 60°C dielectric reinforcement layer solution for 5 minutes, then taken out and dried at 60°C for 1 hour to complete the attachment of a dielectric reinforcement layer. The above operation was repeated 6 times to obtain a multi-interface dielectric filter material with a total dielectric reinforcement layer thickness of 90 μm.

[0061] Example 2

[0062] The multi-interface dielectric filter material in this embodiment includes a fabric substrate and a dielectric reinforcement layer:

[0063] Fabric base: two layers of mesh (the mesh aperture is evenly distributed between 0.3 and 8 mm), the surface is a three-dimensional warp-knitted hexagonal hollow structure polyester fiber fabric, and the connecting monofilament is a polyester fiber monofilament;

[0064] Dielectric reinforcement layer: the base material is polyvinylidene fluoride, the dielectric particles are micron-sized manganese dioxide particles, and the solvent is dimethylformamide.

[0065] The preparation steps are as follows:

[0066] The 60D polyester fiber monofilament is integrated and woven to obtain a fabric base with a thickness of 1 cm. The square meter weight of the obtained fabric base is 655 g / m 2 ;

[0067] After weighing polyvinylidene fluoride, micron-sized manganese dioxide particles and dimethylformamide in a mass ratio of 5:2.5:100, polyvinylidene fluoride and dimethylformamide were mixed at 25° C. for 2 minutes, and then the micron-sized manganese dioxide particles were added and stirred at 54° C. for 1 hour to obtain a dielectric reinforcement layer solution;

[0068] The fabric substrate was immersed in a 60°C dielectric reinforcement layer solution for 5 minutes, then taken out and dried at 60°C for 1 hour to complete the attachment of a dielectric reinforcement layer. The above operation was repeated twice to obtain a multi-interface dielectric filter material with a total dielectric reinforcement layer thickness of 30 μm.

[0069] Example 3

[0070] The multi-interface dielectric filter material in this embodiment includes a fabric substrate and a dielectric reinforcement layer:

[0071] Fabric base: two layers of mesh (the mesh aperture is evenly distributed between 0.3 and 8 mm), the surface is a three-dimensional warp-knitted hexagonal hollow structure polyester fiber fabric, and the connecting monofilament is a polyester fiber monofilament;

[0072] Dielectric reinforcement layer: the base material is polyvinylidene fluoride, the dielectric particles are micron-sized manganese dioxide particles, and the solvent is dimethylformamide.

[0073] The preparation steps are as follows:

[0074] The 60D polyester fiber monofilament is integrated and woven to obtain a fabric base with a thickness of 1 cm. The square meter weight of the obtained fabric base is 655 g / m 2 ;

[0075] After weighing polyvinylidene fluoride, micron-sized manganese dioxide particles and dimethylformamide in a mass ratio of 5:2.5:100, polyvinylidene fluoride and dimethylformamide were mixed at 26° C. for 0.5 min, and then the micron-sized manganese dioxide particles were added and stirred at 60° C. for 1 h to obtain a dielectric reinforcement layer solution;

[0076] The fabric substrate was immersed in a 60°C dielectric reinforcement layer solution for 5 minutes, then taken out and dried at 60°C for 1 hour to complete the attachment of a dielectric reinforcement layer. The above operation was repeated 4 times to obtain a multi-interface dielectric filter material with a total dielectric reinforcement layer thickness of 60 μm.

[0077] Performance testing:

[0078] Polarization voltage:

[0079] A 100-mesh 304 stainless steel metal mesh was used as a polarization electrode to test the polarization voltage of the single-layer filter material and the double-layer filter material of the filter material obtained in Examples 1 to 3. The test results are shown in Table 1.

[0080] Filtration efficiency:

[0081] The PM2.5 filtration efficiency and bacterial filtration efficiency of the multi-interface dielectric filter materials obtained in Examples 1 to 3 were tested respectively, and the test results are shown in Table 1.

[0082] Table 1 Performance test results of multi-interface dielectric filter materials obtained in Examples 1 to 2

[0083]

[0084] From Table 1, it can be seen that the polarization electrode of the single-layer filter material of the multi-interface dielectric filter material obtained by the present invention can reach 10 kV / cm, the PM2.5 filtration efficiency can reach 99.09%, and the bacterial filtration efficiency is above 87.98%. It can be seen that the multi-interface dielectric filter material obtained by the present invention has an excellent air filtration effect.

[0085] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A multi-interface dielectric filter material having a woven structure, characterized in that: The multi-interface dielectric filter material is composed of a fabric substrate and a dielectric reinforcement layer attached to the surface of the fabric substrate; The fabric base comprises two layers of mesh surfaces and connecting monofilaments connecting the two layers of mesh surfaces; The dielectric reinforcement layer includes a matrix material and a solvent.

2. The multi-interface dielectric filter material with a woven structure according to claim 1, characterized in that: The fabric base is made of high dielectric yarns through integrated weaving; The high dielectric yarn is one or more of polyester fiber yarn, polytetrafluoroethylene yarn, polyvinylidene fluoride yarn, polyurethane yarn, polypropylene yarn, polystyrene yarn and polyimide yarn.

3. The multi-interface dielectric filter material with a woven structure according to claim 2, characterized in that: The structure of the high dielectric yarn includes monofilament yarn, multifilament yarn, composite twisted yarn, twisted spun yarn, textured yarn or core-spun yarn; The structure of the mesh surface includes a two-dimensional grid structure, a warp knitting structure, a warp knitting 2.5-dimensional corner interlocking structure, a three-dimensional woven structure or a three-dimensional warp knitting structure.

4. The multi-interface dielectric filter material with a woven structure according to claim 1, characterized in that: The thickness of the fabric base is 0.1 to 5 cm, and the aperture of the mesh surface is 0.1 to 10 mm.

5. The multi-interface dielectric filter material with a woven structure according to claim 1, characterized in that: The dielectric reinforcement layer includes a matrix material, dielectric particles and a solvent.

6. The multi-interface dielectric filter material with a woven structure according to claim 1, characterized in that: The matrix material is one or more of polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride, thermoplastic polyurethane, polydopamine, polyacrylonitrile, polyvinyl pyridone, polystyrene, polyvinyl alcohol, polypropylene, polyamide-6 and polyurethane.

7. The multi-interface dielectric filter material with a woven structure according to claim 5, characterized in that: The dielectric particles are one or more of barium titanate, barium strontium titanate, lead zirconate titanate, calcium copper titanate, manganese dioxide, activated carbon, zinc oxide and copper oxide; The solvent is one or more of dimethylformamide, tetrahydrofuran, acetone, tetramethylurea, dimethyl sulfoxide, trimethyl phosphate and N-methylpyrrolidone.

8. The multi-interface dielectric filter material with a woven structure according to claim 1, characterized in that: The number of the dielectric reinforcement layers is 1 to 10, and the total thickness of the dielectric reinforcement layers is 0.1 to 100 μm.

9. The multi-interface dielectric filter material with a woven structure according to claim 1, characterized in that: The attachment method is one or more of a dipping method, a coating method, a thermal bonding method and a melting method.

10. Use of the multi-interface dielectric filter material with a woven structure as claimed in any one of claims 1 to 9 in air filtration.

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