JP2002035520A - Filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter having excellent dust collection properties, low in pressure loss and excellent in collection efficiency. SOLUTION: The filter is constituted by laminating a sheetlike article (first sheet) having embossed patterns repeating projections or cavities formed thereto and a flat sheetlike article (second sheet). Preferably, the first sheets and the second sheets are alternately laminated and the contact parts of the top parts of the projected parts of the first sheet or the bottom parts of the cavity parts thereof with the second sheet are fused or bonded to form gaps permitting air streams to pass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter, and more particularly, to a filter having excellent dust collecting properties, a low pressure loss, and a high collecting efficiency.

[0002]

2. Description of the Related Art As an air filter used for an air conditioner, an air purifier, an automobile, etc., for example, an electret non-woven fabric is formed into a pleated shape, and an air current is passed through the pleated shape.
There is known a device that adsorbs and removes fine particles such as dust and dust in the air by static electricity. As a method for producing an electretized nonwoven fabric, for example, a method of forming a nonwoven fabric by a melt blow method using a polyolefin such as polypropylene and applying a high DC voltage to the obtained nonwoven fabric is disclosed in JP-A-60-1985. 168511 and JP-A-2-197110. Japanese Patent Publication No. 56-47299 discloses a technique used as a filter.

[0003] However, the filter using the electretized nonwoven fabric having the above-described structure has a problem in that the pressure loss is limited, and there is a problem that the collection life of the fine particles is short because the fine particles are easily clogged. In order to solve such a problem, a filter in which the above-mentioned electret nonwoven fabric is formed into a honeycomb shape has been proposed (Japanese Patent Publication No. 51-52323, etc.). As shown in the partial sectional view of FIG. 1, a honeycomb filter generally has a flat sheet 4 having a large number of peaks 1 and valleys 2 continuously.
Are stacked in multiple stages.

[0004] Such a honeycomb filter has a low pressure loss and contributes to energy saving by reducing the power consumption of home electric appliances, especially air conditioners, and also improves the collection performance by using electretized nonwoven fabric. . However, low pressure loss, high collection performance, and long life cannot all be satisfied, and there is no known filter that satisfies these requirements.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a filter which is excellent in dust collecting property, has low pressure loss, and is excellent in collection efficiency.

[0006]

In order to solve the above-mentioned problems, according to the present invention, a sheet-like material (first sheet) in which an uneven pattern of projections or depressions is formed and a flat sheet-like material (first sheet) are formed. 2 sheets) are laminated.

In the filter according to the present invention, the first sheet and the second sheet are alternately laminated, and a contact portion between the top of the protrusion of the first sheet or the bottom of the recess and the second sheet is fused or bonded. It is preferable that air gaps are formed in the air gap.

[0008] In a preferred aspect of the filter of the present invention, it is preferable that the projections or depressions are arranged so that the airflow passing through the gap meanders by the projections or depressions of the first sheet.

The sheet-like material used in the filter of the present invention is preferably a fibrous material or a film. The fibrous material is preferably selected from non-woven fabric, woven fabric, paper, mesh, and knit. Preferably, the film is a perforated film. The perforated film is preferably a film obtained by subjecting a film formed using a resin containing a filler to a stretching treatment.

[0010] In the present invention, it is preferable that the sheet-like material is electretized.

Further, the sheet material preferably contains at least one agent selected from a deodorant, an antibacterial agent, an antiviral agent, a gas adsorbent, activated carbon and a photocatalyst.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the filter of the present invention will be described in detail. The filter of the present invention is formed of a sheet-like material, and is formed by laminating a first sheet on which an uneven pattern in which protrusions or depressions are repeated is formed, and a flat second sheet.

[0013] The sheet material is usually made of a fibrous material or a film. Specifically, as a fibrous material,
Those selected from nonwoven fabrics, woven fabrics, papers, nets, knits and the like are preferred in terms of stable productivity. In particular, non-woven fabrics such as non-woven fabrics, melt-blown non-woven fabrics, spun-bonded non-woven fabrics, dry non-woven fabrics using short fibers, hydroentangled non-woven fabrics, and wet non-woven fabrics, which are excellent in productivity, are preferred.

Materials used for these fibrous materials include:
Inorganic fibers, metal fibers, natural fibers, synthetic fibers and the like are used. Various inorganic materials such as glass and asbestos are used as the inorganic fibers, and various metals such as copper, stainless steel and aluminum are used as the metal fibers, and the surfaces of the inorganic fibers, natural fibers, and synthetic fibers are coated with the metal. (Evaporated) material can also be used. Further, these fibers may be used as a mixture.

Among them, thermoplastic resins such as polyolefin, polyester, polyamide, polyvinyl chloride, polycarbonate, polyvinyl alcohol, etc., and their modified products (halogen atom, carbonyl group) , A carboxyl group, a nitro group, etc. in a polymer molecule) and a synthetic fiber composed of a mixture thereof. Among them, a non-polar polyolefin-based polymer or a polyolefin composition containing the polyolefin-based polymer as a main component is easily electretized, which is described later, and is excellent in persistence of its charge and collection performance. preferable. The polyolefin composition may contain a small amount of a polyolefin polymer having a polar group.

Examples of the polyolefin polymer having a polar group include: (A) a copolymer of a monomer having a polar group and an α-olefin, for example, pentabromophenyl methacrylate;
Copolymer of 4,6-tribromophenyl methacrylate or the like with α-olefin such as ethylene or propylene; (B) Modification by introducing a polar group into side chain or main chain of polyolefin by oxidation or halogenation A polyolefin, for example, polyethylene or polypropylene, which is oxidized or chlorinated to introduce a carbonyl group, a nitro group, or a chlorine atom in the molecule; (C) a polyolefin or a polymer of the above (B), A modified polyolefin obtained by graft copolymerization of a monomer having a group, for example, a polymer alone such as a modified polyolefin modified with a modified monomer such as an unsaturated carboxylic acid or a derivative thereof, or a mixture thereof is exemplified.

Here, the polyolefin-based polymer or the polyolefin as a base polymer of the modified polyolefin is a homopolymer of α-olefin, a copolymer of two or more α-olefins, or a copolymer selected from these. A mixture of more than one species. As the α-olefin, for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, isopentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-
Hexadecene, 1-octadecene, 1-eicosene and the like can be mentioned.

Specific examples of the polyolefin include polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / 4-methyl- Examples thereof include 1-pentene copolymer, propylene / 1-butene copolymer, and 4-methyl-1-pentene / 1-decene copolymer. Among them, polypropylene, poly 1-butene, poly 4-methyl, which are high in strength, easy to adjust to an appropriate melt viscosity, and easy to mold by melt blow method.
1-Pentene is preferred, and polypropylene is particularly preferred because it is inexpensive and easy to mold, and is easily electretized.

When a polyolefin composition containing an unmodified polyolefin and a modified polyolefin is used as a main material of the perforated film, the content ratio of the modified polyolefin / unmodified polyolefin in the polyolefin composition is usually 0.1% by weight. 1 / 99.9-20 / 80
And preferably about 1/99 to 5/95. In addition, the polyolefin composition, in addition to the modified polyolefin and the unmodified polyolefin, various additives, such as an antioxidant, an ultraviolet absorber, a pigment, a dye, a nucleating agent, and a filler within a range that does not impair the purpose of the present invention. Agents, slip agents, anti-blocking agents, lubricants, flame retardants, plasticizers and the like.

The sheet material used in the filter of the present invention may be composed of a film. The film may be electretized or non-electretized, and may be a perforated film or non-electrified film. Perforated films may be used. Above all, a perforated film having a myriad of fine holes is more preferable because the surface charge density increases as the film surface area increases during electretization.

The substrate constituting such a film may be made of any material and is not particularly limited. Specifically, there can be mentioned those similar to those described above for the fibrous material. In particular, as the polyolefin suitable for the main component of the unmodified polyolefin, high-density polyethylene, low-density polyethylene, linear low-density polyethylene, ethylene / α-olefin copolymer, polypropylene, propylene / α-olefin copolymer, or these And mixtures of two or more of the above.

Here, the ethylene / α-olefin copolymer is a copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms, and the propylene / α-olefin copolymer is It is a copolymer comprising 4 to 12 α-olefins. Examples of the α-olefin having 4 to 12 carbon atoms include 1-butene, 1-pentene and 1-butene.
Hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, etc., among which C4-6
Are preferred.

The perforated film is a film in which fine holes are innumerably formed. The method of producing the film is not only a method by a needle hole processing method, a physical method such as a laser perforation method, but also a filler. In addition, a method of stretching treatment, a method of extracting after forming a film by adding a plasticizer, a method of using a foaming agent and the like can be mentioned.

In the method of stretching by adding a filler, for example, a resin composition to which an inorganic filler or an organic filler is added as a filler is used. In specific examples of the filler, as the inorganic filler, oxides and hydroxides of alkaline earth metals,
Carbonates, sulfates and silicates; examples include oxides, hydroxides, carbonates, sulfates and silicates of Group III elements of the Periodic Table, and organic fillers such as wood flour and pulp. Cellulose powder; crosslinked product powder such as silicone and phenol. Among these, inorganic fillers,
In particular, a porous inorganic filler is preferable from the viewpoint of improving the adhesiveness of the film. Instead of the filler, a functional powder such as a deodorant, an antibacterial agent, a gas adsorbent, a photocatalyst, or activated carbon, which will be described later, can also be used.

The particle size of the filler is usually 0.1 to 10
It is about μm, preferably about 0.5 to 5 μm. The content weight ratio of the resin to the filler in the resin composition (resin / filler) is usually 30/70 to 80/20.

The resin composition to which the filler is added is formed into a film by a known method such as an inflation molding method or a T-die extrusion molding. Next, a stretching treatment is performed to obtain a perforated film. The stretching treatment may be uniaxial stretching or biaxial stretching. At this time, the stretching temperature is adjusted in a temperature range from room temperature to below the melting point of the resin, and the stretching is performed at a stretching ratio of 1.2 to 8 times, preferably 2 to 6 times. Thereby, the porosity is 50%.
As described above, a perforated film having an air permeability of 300 sec or more can be obtained.

In the method of extracting after forming a film by adding a plasticizer, first, the resin composition to which the plasticizer has been added
It is formed into a film by a known method such as die extrusion.
The resin used here is preferably a polyolefin-based polymer, and more preferably polypropylene or polyethylene.

As the plasticizer to be added, a molecular weight of 200
A hydrocarbon plasticizer that is solid at room temperature of 0 or less is preferable,
Specific examples include lower n-alkanes such as docosan, trichosane, tetracosane, and triacontan, paraffin wax, and polyethylene wax. The content weight ratio of the resin to the plasticizer (resin / plasticizer) in the resin composition is usually 20/80 to 75/25.

The formed film is immersed in a solvent capable of extracting and removing the plasticizer, for example, a hydrocarbon solvent such as n-hexane, cyclohexane, or n-butane, and the plasticizer is extracted at a heating temperature of 90 ° C. or lower. Removed. After drying, the film is stretched to obtain a perforated film. In the stretching process,
When the stretching temperature is, for example, 60 ° C. or more and less than 135 ° C., uniaxial stretching or biaxial stretching, preferably biaxial stretching,
The film is stretched at a magnification of at least 3 times and at least 3 times the width. Thereby, a perforated film having a surface area of 70 m ² / g or more, a porosity of 35% or more, and an air permeability of 500 sec or more can be obtained. The extraction of the plasticizer may be performed after the stretching treatment.

A similar perforated film can be obtained by a similar method in which the combination of the plasticizer and the extraction solvent is changed. For example, when water or hot water is used as the extraction solvent, a water-soluble powder whose melting point and decomposition temperature are higher than the melting point of the film material, specifically, sodium chloride, barium chloride, sodium carbonate, polyvinyl alcohol, etc. Can be used in place of the plasticizer. When alcohol is used as the extraction solvent, an alcohol-soluble powder having a melting point or a decomposition temperature higher than the melting point of the film material can be used instead of the plasticizer.

Further, in the case of using a removal method by air flow or vibration instead of removal by the extraction solvent, various kinds of powders that are not compatible with the material in the film forming can be used in place of the plasticizer. Can be used. Specific examples include calcium carbonate, metal powder, and mixtures thereof. These powders are added to a resin to form a film, and a perforated film is obtained in the same manner as in the above-described method of adding a filler and performing a stretching treatment. Aspirate and remove. At this time, it is effective to vibrate the film with a sound wave, an air wave, or a vibration machine. It is preferable that the porous film thus obtained also has the same surface area, porosity, and air permeability as described above.

In the method using a foaming agent, a foam can be easily molded by adding a foaming agent to a resin and keeping the resin under a foaming molding temperature condition. As the foaming agent, depending on the molding method and the molding temperature of the resin foam, decomposition type foaming agents such as sodium bicarbonate, sodium carbonate, azide compound, azodicarbonamide, p-toluenesulfonyl semicabazide, trihydrazinotriazine, etc. And evaporating foaming agents such as aliphatic hydrocarbons, chlorinated aliphatic hydrocarbons, and inert gases. The perforated film used in the present invention needs to be a hole having an opening at least on the surface, and the foam is in a state of closed cells on the film surface and does not have an opening on the surface. In this case, a hole having an opening can be formed by physically roughening or shaving both surfaces of the film. In this case, the expansion ratio of the film is usually 2 to 100 times.

A perforated film having holes and slits which are physically drilled is a film having an innumerable number of minute holes, cuts, or slit-shaped openings with narrow gaps. Examples of the method include a processing method and a needle hole processing method, and a physical method such as a laser drilling method. As an example of the laser drilling method, there is a hole processing using a carbon dioxide gas laser, and processing up to a diameter of 150 μm is possible.

[0034] Among these methods for producing a perforated film,
A method of performing a stretching treatment by adding a filler is preferable. The porous film thus obtained has a porosity of 2% or more, preferably 10% or more, more preferably 20 to 80%, and a surface area (measured by a mercury intrusion porosimeter) of 0.02 m ² / g or more, preferably 0.03 to 100 m ²
/ G, more preferably 0.05 to 80 m ² / g, average pore diameter 0.5 to 100 μm, preferably 1 to 20 μm, more preferably 2 to 10 μm, and thickness usually 10 to 200 μm.
μm, preferably 20 to 100 μm.

The above film or perforated film is
As a non-woven fabric made of defibrated yarn that has been defibrated,
It may be used for the filter of the present invention. The defibration process
The film is slit and stretched, or stretched and slit to form a stretched tape, and the tape is defibrated. Next, a web is formed by a dry or wet method, and the web is entangled to obtain a nonwoven fabric made of a defibrated yarn.

The sheet used for the filter of the present invention is preferably electretized. The electretization can be performed by applying a DC voltage to a fibrous material or a film. In addition, the electretized film can be defibrated to form a nonwoven fabric made of defibrated yarn. The value of the applied DC voltage is appropriately selected according to the shape of the electrodes to be used, the distance between the electrodes, the amount of charge required for the electretized sheet, the processing speed, and the like. For example, when the distance between the electrodes is 8 mm, at least -5 kV, preferably -6 to -30 kV
Can be performed by applying a DC voltage of

The method for applying the DC voltage may be any known method, and is not particularly limited. For example,
A method in which a fibrous material or a film is passed between a pair of electrodes to which a DC voltage is applied; a method in which a corona discharge or a pulsed high voltage is applied to the surface of the fibrous material or a film; A method of holding with another dielectric and applying a DC high voltage to both surfaces can be used. The electretization of the fibrous material or the film may be performed at the time of molding, or may be performed after the molding.

The average surface charge density of the electretized sheet is usually 1 × 10 ^-11 coulomb / c since it can exhibit sufficient dust collection performance as an electret.
m ² or more, preferably 5 × 10 ⁻¹⁰ coulomb / cm ² or more.

In the present invention, the sheet material contains at least one functional agent selected from odorants, antibacterial agents, antiviral agents, gas adsorbents, activated carbon and photocatalysts. Is preferred. Examples of the functional agent include activated carbon, charcoal, bamboo charcoal, Otani stone powder, and theolite having deodorizing and various gas adsorption functions;
Silver zeolite, copper zeolite, titanium oxide (photocatalyst), zinc oxide which also has antibacterial activity against various bacteria such as RSA and Staphylococcus aureus; various polyphenols such as catechin and apple polyphenol which have antibacterial and antiviral activity; silica gel having dehumidifying function , Sodium chloride, charcoal, bamboo charcoal; tourmaline having a function of generating negative ions, and ceramics having a function of generating far and near infrared rays.

When these agents are powder, they are kneaded into a material used for the production of a fibrous material or a film forming a sheet, or dissolved or dispersed in a solvent to obtain a fibrous material or a film. Can be contained by a method such as coating. Among these agents, those which can be formed into a fibrous material can be contained as they are as a sheet-like material or by blending with a fibrous sheet-like material.

Among the above-mentioned agents, those which can be used as a filler for producing the above-mentioned perforated film are as follows:
The stretching in the manufacturing process is particularly preferable because the drug kneaded in the resin is easily exposed on the surface.

A film obtained by solidifying a functional fiber, for example, an active staple fiber, an antibacterial fiber (copper, silver, etc.), a surface coating fiber, a fibrous material composed of mixed fibers, or a functional powder with a binder is used. It can also be used as a perforated film.

Hereinafter, the structure of the filter of the present invention will be described with reference to the drawings. The filter is a sheet-like material on which a repetitive uneven pattern of the projections 6 or the depressions 7 is formed, and includes a first sheet 5 and a flat second sheet 8. The first sheet 5 is formed, for example, by forming a concavo-convex pattern composed of projections 6 and depressions 7 as shown in FIG. 2. As a shaping method, a mold or emboss roll on which the concavo-convex pattern is engraved is used. Compression heat treatment of the sheet at a temperature lower than the melting point.

The height of the projection from the bottom of the recess is usually 10 mm or less, preferably 0.1 to 5 mm, more preferably 0.3 to 3 mm, and the pitch between the projections or the recess is usually 0.2 to 5 mm. 30 mm, more preferably 0.5 to
10 mm.

The first sheet 5 is superimposed on a flat second sheet 8 made of the same sheet-like material, and a contact portion between the top of the projection or the bottom of the depression of the first sheet and the surface of the second sheet is fused. Alternatively, by bonding, the unit 9 is manufactured as shown in FIG. Then, after predetermined number making such unit 9, as shown in FIG. 2 (c), and laminating the first unit 9 ₁ and the second unit 9 _2, the first unit 9
The top of the _first protrusion, the second unit 9 ₂ fusion or adhering to the lower surface, further, similarly to the third unit 9 ₃ laminated on the second unit 9 _2, second the top of the projection of the unit 9 _2, fused or adhered to the third unit 9 ₃ below the surface.

By repeating this laminating and fusing or bonding step, it is possible to form a structure having the gap 10 through which the air flow passes. In the present invention, the first sheet 5 and the second sheet 8 may be the same film or different films. For example, when the electretized perforated film is used as the first sheet 5 and a film containing a functional agent is used as necessary, the second sheet 8 may be an electretized non-perforated film. Will be chosen accordingly.

In FIG. 3, the flow of the air stream on the first sheet 5 is indicated by arrows. The air current flows in from the front of the filter and passes through the filter meandering around the protrusion. First
By arranging the protrusions or depressions on the sheet in this manner, the dust collection efficiency can be increased.

The filter of the present invention is excellent in dust collecting property, low in pressure loss, high in collection efficiency, and can easily contain a functional agent in the filter material. Rich in It operates and produces household air purifiers and air conditioner air purifier filters that use low-output fans, exhaust filter filters for cleaners, air purifier filters for large facilities such as hospitals and buildings; and bioindustries and precision electronic devices. Clean filters for equipment and rooms; air filters for automobiles, buses, airplanes, etc .; and filters containing functional agents in filter media, such as air-conditioning filters for food storage warehouses, rooms, refrigerators, etc. Air-conditioning filters for buildings and rooms for raising animals; Gas adsorption filters for exhaust gas from factories, laboratories, equipment, etc .; Adsorption filters for formalin odor peculiar to museums, museums, newly built rooms, etc .; It is preferably used for a filter such as a filter for adsorption of trace gas in air.

[0049]

Industrial Applicability The honeycomb filter of the present invention has excellent dust collecting properties, low pressure loss, high collection efficiency, and can be preferably used for various air cleaning filters. Further, a filter material containing a functional agent in a filter material is excellent in deodorization and other functions and can be suitably applied to an air-conditioning filter, a gas adsorption filter and the like.

[0050]

EXAMPLES <Preparation of Sheet> [Preparation Example 1] Density 0.91 g / cm ³ , MFR (ASTM D12
A homopolypropylene having a weight of 1.2 g / 10 min (in accordance with 38 and measured at 230 ° C under a load of 2.16 kg) was charged into an extruder, melted, extruded from a T-die connected to the extruder tip, and stretched. A 50 μm thick film uniaxially stretched by a factor of 9 was produced. (Sheet) The film was charged by a charge applying device to which a DC voltage of -30 kV was applied to obtain a sheet.

[Production Example 2] 30% by weight of activated carbon (BPL manufactured by Toyo Calgon Co., Ltd.) in the same polypropylene as in Production Example 1
And molded as in Production Example 1 to a thickness of 5
A 0 μm film was produced. (Sheet) The film was charged by a charge applying device to which a DC voltage of -30 kV was applied to obtain a sheet. [Preparation Example 3] The sheet obtained in Preparation Example 1 was defibrated, and a fibrous sheet having a basis weight of 50 g / m ² was prepared using the obtained defibrated yarn. (Sheet)

[Embodiment] Each of the sheets (-) obtained in the above-mentioned preparation example was subjected to a heat treatment using a pair of shaping rolls having a concave-convex pattern in which projections or depressions were repeated, and the projections from the bottoms of the depressions were formed. A first sheet having a concavo-convex pattern having a height of 1.0 mm was produced. This first sheet is superimposed on a flat second sheet of the same sheet,
A contact portion between the top of the protrusion of the first sheet or the bottom of the depression and the surface of the second sheet was bonded using a hot-melt adhesive to produce a unit as shown in FIG. 2B. Using the 50 units, a width of 200 mm, a length of 50 mm, and a depth of 10 m is obtained by the method described in FIG.
m were prepared. Pressure loss and collection efficiency were measured using this filter. In addition, evaluation was made on the odor removal performance of tobacco. Table 1 shows the results.
Shown in

[0053]

[Table 1]

Measurement of Collection Efficiency The collection efficiency was measured using an apparatus schematically shown in FIG. First, the aerosol generator (manufactured by Nippon Kagaku Kogyo) 21 to N
aCl particles (particle size: 0.3 to 0.5 μm) were supplied through an air filter 22 into a chamber 23 into which clean air was introduced. After the concentration of NaCl in the chamber becomes constant (2 to 6 × 10 ⁶ / cm ³ ), suction is performed in the direction of the arrow by the suction device 24 through the filter sample 25 arranged at the bottom of the chamber 23. When the wind speed passing through the filter becomes a constant speed (10 cm / sec), the N on the upstream 26 and downstream 27 sides of the filter sample 25 is reduced.
The aCl particle concentration C _in and C _out were measured by a particle counter (KC-01B manufactured by Rion) 28a, 28, respectively.
b, and the collection efficiency was determined by the following equation.
29 is a flow meter, 30 is a flow control valve. Collection efficiency (%) = (1−C _out / C _in ) × 100

Measurement of pressure loss Using a differential pressure gauge (KD146 manufactured by Yamatake Honeywell), the measurement was performed simultaneously with the measurement of the collection efficiency. However, the wind speed is 1m / sec
And Tobacco odor removal performance According to the Japan Electrical Manufacturers' Association standard JEM1467 household air purifier dust collection performance test, the filter sample is attached to a commercially available air purifier using the dust collection capacity measurement room and cigarette smoker described in the Appendix. A one-hour dust collection performance test was performed. A sensation test was conducted by nine persons for the smell of cigarettes in the dust collecting capacity measurement room, and evaluated according to the following criteria. 5 or more out of 9 people felt that the odor was removed, △ felt that the odor was not removed so much, and × felt that the odor was not removed at all compared to the case where the removal was not performed by the filter. Was.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a conventional honeycomb air filter element.

FIG. 2 is a diagram illustrating an example of a method for manufacturing an air filter according to the present invention.

FIG. 3 is a diagram illustrating the flow of airflow on a first sheet.

FIG. 4 is a schematic diagram showing a configuration of an apparatus used for measuring a collection efficiency.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 peak portion 2 valley portion 3 sheet having continuous peak portion and valley portion 4 flat sheet 5 first sheet 6 protrusion 7 depression 8 second sheet 9 unit 10 gap 11 air flow 21 aerosol generator 22 air filter 23 Chamber 24 Suction device 25 Filter sample 26 Upstream 27 Downstream 28a, 28b Particle counter 29 Flow meter 30 Flow control valve

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) B32B 3/28 B32B 3/28 C 4J002 5/26 5/26 C08J 5/18 CES C08J 5/18 CES C08K 3/00 C08K 3/00 5/00 5/00 C08L 101/00 C08L 101/00 F term (reference) 4C080 AA05 AA07 BB02 BB05 BB10 CC01 HH05 JJ05 JJ06 KK08 MM02 MM05 MM40 QQ11 4D019 AA01 BA13 BB03 BB08 BB10 BC01 BD01 CB03 CB06 4D054 AA12 AA13 BC16 EA22 EA27 4F071 AA09 AA14 AA20 AA24 AA29 AA43 AA50 AA54 AA78 AB03 AB15 AB18 AB21 AB24 AB26 AC19 AE04 BA01 BB06 BC01 BC09 4F100 AA37A AA37B AA37H AK07 AT00B BA02 CA12 CA23 DC11A DC11B DD01A DG01A DG01B DG10A DG10B DG11A DG11B DG12A DG12B DG15A DG15B DJ06A DJ06B EC03 EC033 EC172 EC18 EC183 EH17 EJ40 EJ402 GB56 HB21A JC00 JC00A JC00B JL08A JL08B 4J002 AB012 AH0 02 AH003 BB031 BB121 BB141 BB151 BB171 BB201 CC022 CP022 DA017 DD057 DE066 DE107 DE137 DE236 DG046 DG056 DJ006 DJ007 DJ017 EL097 FD012 FD016 FD020 FD183 FD187 GD05

Claims (9)

[Claims] 1. A filter comprising: a sheet-like material (first sheet) on which an uneven pattern of repeated projections or depressions is formed; and a flat sheet-like material (second sheet). 2. The method according to claim 1, wherein the first sheet and the second sheet are alternately stacked, and a contact portion between the top of the protrusion of the first sheet or the bottom of the recess and the second sheet is fused or adhered to form an air current. The filter according to claim 1, wherein a void is formed to pass through. 3. The filter according to claim 1, wherein the projections or the depressions are arranged such that the airflow passing through the gap is meandered by the projections or the depressions of the first sheet. 4. The filter according to claim 1, wherein the sheet is a fibrous material or a film. 5. The filter according to claim 4, wherein the fibrous material is selected from a non-woven fabric, a woven fabric, a paper, a mesh, and a knit. 6. The filter according to claim 4, wherein the film is a perforated film. 7. The filter according to claim 6, wherein the perforated film is a film obtained by stretching a film formed using a resin containing a filler. 8. The filter according to claim 1, wherein the sheet is formed into an electret. 9. The sheet-like material contains at least one agent selected from deodorants, antibacterial agents, antiviral agents, gas adsorbents, activated carbon and photocatalysts.
The filter according to any one of the above.