JP2002085930A - Air filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air filter having practically sufficient dust removing performance and excellent in air air-permeability in use for mounting it on an air conditioner such as an air cleaner. SOLUTION: The air filter is obtained by corrugating a filter medium characterized by having >=99% capture efficiency of 0.3 μm particles in wind-speed of 5.3 cm/s and pressure drop of <=50 Pa measured in accordance with form 1 of JIS-B-9908, or a filter medium characterized by having >=98% capture efficiency and pressure drop of <=35 Pa.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air filter, and more particularly, to an air filter having excellent dust removal and high air permeability, which is mounted on an air conditioner such as an air purifier.

[0002]

2. Description of the Related Art In recent years, air purifiers have been widely used in homes and workplaces due to changes in living environment and heightened health consciousness. In recent years, various air conditioners, such as room air conditioners, dehumidifiers, and humidifiers, as well as dedicated air purifiers, tend to have an air purifying function, and have been put to practical use.

In recent years, even in general households,
For example, it is required to efficiently collect fine particles of sub-micron order represented by tobacco smoke, various pathogens and viruses, etc., and a high-efficiency dust filter developed for industrial use such as a clean room, that is, a rated air volume 99.9 for particles having a particle size of 0.3 μm.
A HEPA filter having a collection efficiency of 7% or more and a ULPA filter having a collection efficiency of 99.999% or more for particles having a particle size of 0.15 μm are mounted on a household air cleaner or the like.

[0004] Such a high-efficiency dust filter generally has a high pressure loss, so that the load on the blower becomes large, the device becomes large, the power consumption of electric power increases, and the quietness decreases. was there.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an air filter which has practically sufficient dust-removing performance and excellent air permeability when used in an air conditioner such as an air purifier. It is to be.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have completed the following invention.

(1) 0.3 μm at a wind speed of 5.3 cm / sec measured according to JIS-B-9908 Type 1
The collection efficiency of m particles is 99% or more and the pressure loss is 50P
(a) an air filter formed by processing a filter material into a wave shape,

(2) 0.3 μm at a wind speed of 5.3 cm / sec measured according to JIS-B-9908 type 1
Collection efficiency of m particles is 98% or more and pressure loss is 35P
(a) an air filter formed by processing a filter material into a wave shape,

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The air filter of the present invention will be described in detail below.

The filter medium according to the present invention has a predetermined collection efficiency and a predetermined pressure loss. Although such a filter medium is not particularly limited, it is mainly classified into two types: a filter for collecting dust mainly by mechanical filtration and an electret filter for collecting dust mainly by electrostatic adsorption. Apart from that, there is an intermediate filter that combines mechanical filtration and electrostatic adsorption.

As an example of the filter medium of the filter of the present invention, there is a filter manufactured by a wet papermaking method. Generally, such a filter medium is composed of 90 to 95% or more by weight of glass fiber and 5 to 10% or less of a binder, and the glass fiber has a length of 1 to 3%.
mm, the average diameter is 0.7 μm, the thickness is very fine, and the variation in thickness is large.
Many are made of chop fibers having a length of 5 mm or more, but are not particularly limited thereto, and are made of ceramic fibers, cellulose fibers, polyolefin fibers such as polypropylene, organic fibers such as polyester fibers or aramid fibers. There may be.

As a method for producing a filter medium of a filtration type filter made of organic fibers, in addition to the above-mentioned wet papermaking method,
A dry nonwoven fabric manufacturing method such as a melt blown method, a flash spinning method, or a spun bond method may be used.

The electret filter according to the present invention is a filter which retains electric polarization semipermanently and applies an electric force to the outside, and traps particles by the electrostatic force. Examples of the charging method include an electro-electret, a heat electret, a radio-electret, a mechano-electret, a photo-electret, a magnet-electret, and the like, and those used industrially in a nonwoven fabric filter are mainly an electro-electret and a heat-electret. As the material, polypropylene or a copolymer mainly composed of propylene is often used, and an appropriate amount of a fatty acid metal salt such as aluminum stearate may be added to the above resin material for the purpose of improving heat resistance.

[0014] As an intermediate filter medium having both mechanical filtration and electrostatic adsorption according to the present invention, an intermediate filter medium having a collection efficiency of about 80 to 95% and an electret filter medium are used in combination, and a melt blown filter. Type electret filter and the like.

[0015] The method of producing an intermediate filter medium by using both the high-performance filter medium and the electret filter medium according to the present invention may be simply superimposed, but they are laminated to obtain a filter medium suitable for corrugated processing. Preferably, a method of laminating by fusion by a pin sonic method or the like and a method of laminating by adhesion by a hot melt powder laminating method such as a hot melt spray method or a so-called sinter method, and the like, but the laminating method includes It is not limited.

Further, the melt blown electret filter according to the present invention uses a polypropylene or the like as a raw material as described above, and applies a high voltage during melt blown spinning, during semi-melting on a drum, or immediately after solidification to form a heat electret filter. It can be produced by charging fibers, or may be produced by subjecting a relatively dense and thin melt blown body to charging treatment by corona discharge or the like.

In the case where the strength of the filter medium is low and the filter medium is broken when processed into a wavy shape, or in the case where the filter medium is soft and it is difficult to form a wavy form, a gas-permeable base material called an aggregate can be used in combination. The combination of aggregates may be simply superimposed,
The filter medium and the aggregate may be laminated and integrated. Examples of the aggregate according to the present invention include spun-bonded nonwoven fabric, resin-bonded nonwoven fabric, thermal-bonded nonwoven fabric, resin net, and the like, but are not particularly limited thereto. It can be appropriately selected according to the content of processing and the like.

As a method of processing the filter medium according to the present invention into a wavy shape, a valley-like folding process generally called pleating or a corrugated midline waving process in corrugated cardboard processing can be mentioned. By processing in such a wavy manner, the area of the filter medium can be increased with respect to a constant ventilation area, and the linear velocity of the air passing through the filter medium with respect to a specific airflow is relatively reduced. The pressure loss is reduced, the air permeability is improved, the collection efficiency is improved and the life of the dust collection performance is prolonged, and the rigidity of the filter itself is increased compared to the use of a single plate, and the filter is installed. There is an advantage that handling at the time of and replacement is improved.

In the air filter of the present invention, a thermoplastic resin such as polyethylene is applied continuously or intermittently linearly between the corrugated adjacent filter media for the purpose of securing a space between adjacent corrugated filter media and reinforcing the filter media. A so-called beating process may be performed, and a separator made of a corrugated aluminum plate or the like may be attached to the valley of the corrugated filter medium, or
A saw-shaped spacing plate that can be inserted between adjacent filter media in a wavy shape, a band-shaped film or a net that connects the peaks of the waves, or the like may be attached.

Regarding the dust collection performance of the air filter according to the present invention, the Japan Electrical Manufacturers' Association standard JEM-1467-1 is used.
Dust collection performance test is stipulated in 995 "Home air purifier", and it measures the practical dust collection performance of not only home air purifiers but also various commercial air purifiers and air conditioners such as room air conditioners. It has been adopted as a method.

When the practical dust collecting performance is measured in accordance with this standard JEM-1467, there is no substantial difference in an air filter formed by processing a filter material having a filter material collection efficiency of 99% or more into a wavy shape. Collection efficiency of filter media, that is, JIS-B-
9908 Wind speed measured according to format 1 5.3 cm /
It can be seen that a collection efficiency of 0.3 μm particles per second is sufficient if it is 99% or more.

Here, the collection efficiency of the filter medium is a maximum value in which only the lower limit is defined, but generally, the higher the collection efficiency, the higher the pressure loss and the lower the air permeability.
Particularly, in a region where the collection efficiency is 99% or more, a slight improvement in the collection efficiency may cause a significant increase in pressure loss.
Pressure loss of the filter medium according to the present invention, that is, JIS-B-
9908 Wind speed measured according to format 1 5.3 cm /
The pressure loss in seconds is preferably 50 Pa or less, more preferably 35 Pa or less.

The pressure loss of the filter medium, that is, JIS-B-9
908 If the pressure loss at a wind speed of 5.3 cm / sec measured in accordance with Type 1 exceeds 50 Pa, the air filter must be large in order to secure air permeability, or in order to withstand high pressure loss. Problems such as an increase in the size of the device due to an increase in the size of the blower, an increase in the consumption of power energy due to an increase in the load on the blower, and a decrease in the quietness, etc., are of low practicality. .

The collection efficiency of the filter medium, that is, JIS-
Wind speed 5.3c measured according to B-9908 Type 1
The collection efficiency of 0.3 μm particles at m / sec may be 98% or more, and a practical dust collection performance in accordance with JEM-1467 of an air filter obtained by processing such a filter material into a wave shape is measured. Then, although the dust collection performance is slightly inferior to the case of the filter medium having a collection efficiency of 99% or more, the practical dust collection performance is maintained at a level without any problem, and the collection efficiency is 99% or more. There is an advantage that the air permeability can be increased as compared with the case of the above filter media.

Therefore, the first invention of the present invention and the first invention of the present invention depend on whether the dust collection efficiency is strictly prioritized, or whether the air permeability is prioritized by giving up to a practically satisfactory level of dust collection performance. Either of the second inventions can be selected. In other words, when giving priority to the dust collection efficiency of the air filter and maximizing the dust collection performance of an apparatus equipped with the air filter, the air filter of the first invention of the present invention may be used, and If priority is given to air permeability within a range where the typical dust collection performance is almost equal to the highest performance, the air filter of the second invention of the present invention may be used.

On the other hand, the dust collection efficiency of the filter medium, that is, JIS-
Wind speed 5.3c measured according to B-9908 Type 1
JE of an air filter formed by processing a filter medium having a collection efficiency of less than 98% of 0.3 μm particles at m / sec into less than 98%.
Practical dust collection performance measured in accordance with M-1467 is a high-performance filter medium having a collection efficiency of 99% or more, particularly 99.9.
Compared to an air filter obtained by processing a 7% or more HEPA filter material into a wave shape, its practical dust collection performance is clearly lower, and it takes time to reach the same air cleanliness, which is not preferable.

The air filter of the present invention may be deodorized, antibacterial, and / or deodorized, if desired, without departing from the spirit of the present invention.
Antivirus, antifungal, insect repellent, insect repellent, pest repellent, harmful substance removal, deodorant, aroma, dehumidification, humidity control, moisture absorption (dry), moisture (humidity) permeation, oil and other adsorption and water and volatile chemicals It may have various functions such as evaporation or sustained release, and for example, may be a composite filter using a deodorizing filter, an antibacterial filter and the like in combination.

As a method of obtaining such a composite filter, a method of supporting an antibacterial agent or a deodorant on an aggregate for improving the foldability of the filter material, a filter material superimposed on a deodorant filter or an antibacterial filter, or a filter material laminated therewith. Examples of the method include a method of using the method, and a method of integrating a filter material formed into a wavy shape with a deodorizing filter, an antibacterial filter, and the like by frame processing.

[0029]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto unless it exceeds the gist of the invention.

Example 1 A collection efficiency of 0.3 μm particles at a wind speed of 5.3 cm / sec measured according to JIS-B-9908 type 1 is 9
Using a filter medium of 9.1% and a pressure loss of 50 Pa, the filter was folded into a pleated shape having a peak height of 30 mm and a pitch of 4 mm to frame the periphery, thereby producing an air filter of Example 1 having an outer dimension of 250 mm × 250 mm.

Example 2 In Example 1, instead of a filter medium having a collection efficiency of 99.1% and a pressure loss of 50 Pa, the collection efficiency was 98.0%.
An air filter was prepared in the same manner as in Example 1 except that the filter medium had a pressure loss of 35 Pa, and was used as an air filter of Example 2.

Comparative Example 1 In Example 1, the collection efficiency was 99.9% and the collection efficiency was 99.97 instead of the filter medium having a pressure loss of 50 Pa.
%, And an air filter was prepared in the same manner as in Example 1 except that the filter medium had a pressure loss of 97 Pa, and was used as an air filter of Comparative Example 1.

Comparative Example 2 In Example 1, the collection efficiency was 96.7% instead of the filter medium having a collection efficiency of 99.1% and a pressure loss of 50 Pa.
An air filter was produced in the same manner as in Example 1 except that the filter medium had a pressure loss of 28 Pa, and this was used as an air filter of Comparative Example 2.

Next, the performances of the air filters of Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 1.

[Dust collection performance test] Maximum 300 mm x 300
The air filter of the example or the comparative example is mounted on a test air purifier including a housing capable of mounting a filter having a size of up to a millimeter size and a dielectric motor type axial flow fan installed in the housing, and the air volume is adjusted to 3 m by voltage adjustment. Set to ³ / min,
Using this test air purifier, JEM-1467-1 was used.
A dust collection performance test was performed in accordance with 995. The dust collection performance was measured by measuring the time required for the dust concentration to reach 1/3 of the initial concentration before the start of operation, and expressed as operation time (minutes).
The shorter the operation time, the better the dust collection performance.

[Measurement of power consumption] The same test air purifier as the dust collection performance test equipped with the air filter of the example or the comparative example was set to a flow rate of 3 m ³ / min by voltage adjustment, and the set voltage at this time was set. The value (V) was expressed as a relative value with the case of Example 1 as a reference (1.0).

[Noise Measurement] The same test air purifier as in the dust collection performance test equipped with the air filter of the example or the comparative example was set to an air volume of 3 m ³ / min by voltage adjustment, and the air volume was set to 1 m ³ . It was installed on a vibration-proof material in an acrylic resin container to block external sound as much as possible, and the noise (dB) at a position 50 cm away from the exhaust hole was measured using a sound level meter.

[0038]

[Table 1]

From the results shown in Table 1, the air filter of Example 1 corresponding to the first invention of the present invention has the same dust collection performance as the air filter of Comparative Example 1 having a high performance equivalent to HEPA. It can be seen that the power consumption is low and the noise is low. In the air filter according to the second embodiment corresponding to the second invention of the present invention, although the dust collection performance is slightly reduced, it falls within a practically acceptable level (+ 10% or less). It can be seen that the noise is even better than the air filter of Example 1.

[0040]

According to the present invention, the practical dust collection performance when installed in an air conditioner such as an air purifier maintains the same high dust collection performance as a high performance filter such as HEPA.
In addition, it is possible to obtain an extremely useful air filter which has excellent air permeability and can achieve reduction in power consumption, improvement in quietness, and downsizing of the device.

Claims (2)

[Claims] 1. It is required that the collection efficiency of 0.3 μm particles at a wind speed of 5.3 cm / sec measured according to JIS-B-9908 type 1 is 99% or more and the pressure loss is 50 Pa or less. An air filter made by processing the characteristic filter material into a wave shape. 2. A collection efficiency of 0.3 μm particles at a wind speed of 5.3 cm / sec measured according to JIS-B-9908 type 1 is 98% or more and a pressure loss is 35 Pa or less. An air filter made by processing the characteristic filter material into a wave shape.