JP2004275798A - Air cleaning filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adsorptive filter which does not cause the falling of an adsorbent from the filter and has excellent workability and productivity. <P>SOLUTION: This air cleaning filter comprises an adsorptive filter material which is pleated and is made by depositing the particulate adsorbent between fiber layers of two layers or more and a frame body holding the adsorptive filter material. Further, the end parts of the pleated filter material are sandwiched by the frame body and peak part filter materials which are adjacent to the end parts of the filter material. Therein, the particulate porous adsorbent is retained between the fiber layers and, thereby, the falling of the adsorbent can be prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
INDUSTRIAL APPLICABILITY The present invention is used for an air purification filter used when air is introduced into a building or when air conditioning is performed while circulating indoor air, or for use in vehicles such as automobiles, trains, home use, and air purifiers for business use. The present invention relates to an air purification filter to be used.
[0002]
[Prior art]
2. Description of the Related Art A filter made of a filter medium containing a gas adsorbent is generally used as an air purification filter for removing gaseous substances in a space where a person lives, such as in a building room or a vehicle room such as a car or a train.
As the above-mentioned gas-adsorbing filter media, those obtained by combining a gas-adsorbing material such as granular or powdered activated carbon, zeolite, or silica gel into a sheet have become widespread. And processed into various forms to achieve filter performance.
The adsorptive filter medium is used after being processed into a pleated shape in order to enhance the performance as an air purification filter. By the pleating process, the filter medium can be packed several times to several tens times in a certain area, and as a result, the gas removal efficiency and the removal capacity can be significantly improved.
[0003]
In addition, the pleated filter medium often has a filter medium holding frame in consideration of the handleability as a filter and the mountability to an air cleaning device.
The method of joining the adsorptive pleated filter medium to the holding frame is to cut the pleated filter medium at a predetermined number of peaks and then join the frame and the filter medium with an adhesive, but the cut surface of the filter medium is exposed. However, there is a problem that the adsorbent falls off from the cut surface and scatters during use.
As a method to solve this problem, after bonding the pleated adsorptive filter medium and the frame, cover the cut surface with a cover sheet, heat the cut surface to fuse the fiber layer and the adsorbent, or apply an adhesive to the cut surface. Although there is a method of preventing the falling-off by applying the falling-off preventing agent to be applied, there are problems that the number of processing steps is increased, and that a predetermined filter size cannot be obtained by adding the falling-off preventing agent.
Patent Literature 1 discloses a method of closing an end face of a filter containing an adsorbent by a heat press treatment to prevent the adsorbent from dropping off the end face of the filter. However, this filter does not have a frame on the end face that has been subjected to the fall-prevention treatment, and when a frame is required on the entire side surface, a frame joining step is required after the fall-prevention treatment, which makes the manufacturing process complicated. was there.
Further, as a method for joining the adsorptive pleated filter medium and the frame, there is an insert molding method using a thermoplastic resin. In this method, since the cut surface of the pleated filter material is fixed in the resin frame, the adsorbent does not fall off in the filter shape, but the adsorbent falls off in the insert molding die and the die wears. And the cost of the mold is high.
[0004]
[Patent Document 1]
JP-A-11-222412
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and provides an adsorptive filter which does not cause the adsorbent to fall off from the filter and has excellent workability and productivity.
[0006]
[Means for Solving the Problems]
That is, the present invention relates to an air purifying filter comprising an adsorptive filter medium in which a granular adsorbent is carried between at least two pleated fiber layers and a frame holding the filter medium, wherein the end of the pleated filter medium is provided. An air purification filter characterized by being sandwiched between a frame and a mountain filter medium adjacent to a filter medium end.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
The air purification filter of the present invention needs to have a pleated shape. This is because the pleating process allows the filter medium to be packed several times to several tens times in a certain area, and as a result, the gas removal efficiency and the removal capacity can be significantly improved.
In the adsorptive filter medium of the present invention, it is necessary that the granular porous adsorbent is carried between at least two or more fiber layers. The granular porous adsorbent can be pleated by being held between the fiber layers, and can prevent the adsorbent from falling off on the surface of the filter medium.
[0008]
The method of supporting the adsorbent between the fiber layers is not particularly limited, but a method of sandwiching the adsorbent and the thermoplastic binder mixture between the fiber layers and heating and adhering the mixture is preferable. As the thermoplastic binder, various forms and materials such as a fibrous form and a granular form can be used. Depending on the required characteristics of the filter, the adsorbing layer may be laminated in multiple stages via the fiber layer.
Although the fiber layer is not particularly limited, it is preferable that the openings have such an extent that the adsorbent to be carried does not pass therethrough. A fiber layer of 10 to 200 g / m ² can be selected according to the size of the adsorbent. As an example, a nonwoven fabric made of polyolefin fiber or polyester fiber and having a fiber diameter of about 1 to 100 microns and a thickness of about 0.1 to 2 mm can be arbitrarily selected.
[0009]
Various adsorbents having a deodorizing effect, such as activated carbon, zeolite, silica gel, alumina, photocatalyst, and metal oxide, can be used alone or in combination as the particulate adsorbent of the present invention.
It is particularly preferred when the particulate adsorbent is activated carbon. Activated carbon has a good balance of deodorizing performance against various odors, and is easily available.
The particle size of the granular adsorbent is not particularly limited, but a particle having a particle size of about 1 micron to 1000 microns can be arbitrarily used. If the particle size is too small, the airflow resistance of the filter increases, and if the particle size is too large, the air purification performance tends to decrease. Therefore, it is preferable to set the average particle size between 100 and 500 microns.
[0010]
The basis weight of the particulate adsorbent is not particularly limited, but is preferably set between 10 and 1000 g / m ² . If the basis weight is less than 10 g / m ² , the air purification performance is insufficient, which is not preferable. If the basis weight is 1000 g / m ² , the airflow resistance increases, which is not preferable.
Next, a method for joining the pleated adsorptive filter medium to the frame will be described. The pleated adsorptive filter medium 1 of an arbitrary width is added to the required number of peaks, and the peaks are cut in the width direction 2 of the filter medium from 1/2 to 1 peak. The number of peaks added at the time of cutting can be arbitrarily set between 1/2 peak and 1 peak, but is particularly preferably between 3/5 peak and 9/10 peak. If it is smaller than 3/5 peaks, the strength at the time of adhering the filter medium and the frame is reduced, which is not preferable. If it is larger than 9/10 peaks, the activated carbon tends to fall off from the end of the filter medium even if it is adhered to the frame. Not preferred.
[0011]
Next, the width direction frame body 4 having a size longer than the width of the filter medium and larger than the height of the filter medium pleat is adhered to the end portion 3 of the pleated filter medium that has been cut. At the time of bonding, it is necessary to bond the filter medium end portion 3 in such a manner that the filter material end portion 3 is sandwiched between the frame body width direction frame 4 and the end portion adjacent filter medium 6. By sandwiching the filter material end portion 3 between the width direction frame body 4 and the end portion adjacent filter medium 6, even if the adsorbent falls off from the end portion, the fallout remains between the frame body and the pleated filter medium and goes out of the filter. It does not fall off.
[0012]
The method of bonding the width direction frame and the pleated filter medium is not particularly limited, and a method of applying an adhesive to the frame, a method of applying an adhesive to the pleated filter medium, a method of using a double-sided tape, and the like can be used.
[0013]
The type of the frame is not particularly limited, and a cardboard material, a polymer nonwoven fabric, a woven fabric, a plastic, or the like can be used. The thickness of the frame is not particularly limited, but is preferably 0.1 mm or more and 10 mm or less. If the thickness is less than 0.1 mm, the strength is decreased, and if it is 10 mm or more, the effective filter medium area of the filter is decreased. Not preferred.
Similarly, after the opposite width direction frame and the pleated filter are bonded, the pleat direction frame 5 and the pleated filter are bonded. As the bonding method, the same bonding method as that for the width direction frame can be used. It is also possible to reverse the order of bonding the pleated frame and the width frame.
[0014]
Hereinafter, the present invention will be specifically described with reference to examples. However, the examples do not limit the present invention in any way, and all modifications that do not depart from the gist of the preceding and following descriptions are included in the technical scope of the present invention. Is done.
First, the measurement method used in the following examples will be described.
[0015]
1. After confirming that the adsorbent is not detached or adhered from the filter material surface, the filter filtration surface is placed horizontally on the ground, and freely dropped from a height of 50 cm onto a smooth and clean table. This is repeated three times, and the number of adsorbents desorbed from the filter is counted visually, and this is defined as the amount of dropout per filter.
[0016]
(Example)
As the adsorptive filter material, an active carbon-containing filter material in which activated carbon and a binder mixture (300 g in total weight and 300 μm in activated carbon particle size) are sandwiched between a polyester spunbond nonwoven fabric having a width of 200 mm (80 g, fiber diameter 30 μ, thickness 0.5 mm) is used. This filter medium was pleated at a peak height of 30 mm, and cut in the width direction at the position of 1/4 peak every 22 peaks. Prepare a frame material (70 g per area polyester nonwoven fabric, thickness 0.2 mm, 200 mm x 30 mm) coated with hot melt adhesive, and glue the cut pleated filter media so that the cut end is sandwiched between the adjacent mountain and frame. I let it. After equalizing the pleat spacing, the pleat surface was similarly pressed with a hot melt adhesive applied frame material to the filter media pleat surface and adhered, and the air purification filter with dimensions 200 x 200 x 30 mm and 20 effective peaks Got. When the dropping property test was conducted, no activated carbon was dropped from the cut surface of the filter medium, and the dropping amount was 0.
[0017]
(Comparative Example 1)
As the adsorptive filter medium, the same filter medium as in the example was used. This filter medium was pleated at a peak height of 30 mm and cut in the width direction at every 21 peaks. With respect to the cut pleated filter medium, half of the pleat was adhered to a frame material (70 g basis weight polyester nonwoven fabric, thickness 0.2 mm, 200 mm × 30 mm) coated with a hot melt adhesive. After equalizing the pleat spacing, the pleat surface was similarly pressed with a hot melt adhesive applied frame material to the filter media pleat surface and adhered, and the air purification filter with dimensions 200 x 200 x 30 mm and 20 effective peaks Got. When a drop-off property test was performed, the activated carbon was remarkably dropped from the cut surface of the filter medium, and the drop-off amount was 75.
[0018]
(Comparative Example 2)
As the adsorptive filter medium, the same filter medium as in the example was used. This filter medium was pleated at a peak height of 30 mm and cut in the width direction at every 21 peaks. Next, the cut end face of 5 mm was subjected to heat fusion processing with a 120 ° C. heat sealer. About this pleated filter medium, half of the pleat was adhered to a frame material (70 g basis weight polyester nonwoven fabric, thickness 0.2 mm, 200 mm × 30 mm) coated with a hot melt adhesive. After equalizing the pleat spacing, the pleat surface was similarly pressed with a hot melt adhesive applied frame material to the filter media pleat surface and adhered, and the air purification filter with dimensions 200 x 200 x 30 mm and 20 effective peaks Got. When the dropping property test was performed, no activated carbon was dropped from the cut surface of the filter medium, and the falling amount was 28.
[0019]
As described above, in Comparative Example 1, since the end of the filter medium is exposed outside the filter, the particulate adsorbent falls off from the end. In Comparative Example 2, the end portion was subjected to a heat-sealing process to prevent falling off. However, since the end portion was exposed to the outside of the filter, a portion of the end portion that did not contact the fiber layer during the heat-sealing process. The adsorbent has fallen off. On the other hand, in the embodiment, since the end of the filter medium is sandwiched between the frame and the adjacent pleated filter medium, the adsorbent does not fall off from the filter medium.
[0020]
【The invention's effect】
As described above, by applying the present invention, it is possible to provide a pleated air purification filter that prevents the adsorbent from falling off without increasing the number of processing steps.
[Brief description of the drawings]
FIG. 1 is a perspective view for explaining an embodiment of the present invention. FIG. 2 is a cross-sectional view for explaining an embodiment of the present invention.
1: pleated adsorptive filter medium 2: filter medium width direction 3: end portion 4: width direction frame 5: pleated direction frame 6: end portion adjacent filter medium

Claims (2)

In an air purifying filter comprising an adsorbent filter medium in which a granular adsorbent is supported between at least two pleated fiber layers and a frame holding the filter medium, the end of the pleated filter medium is a frame and a filter medium end. An air purifying filter characterized by being sandwiched by a mountain filter medium adjacent to a part. 2. The air purification filter according to claim 1, wherein the particulate adsorbent is activated carbon.

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