JPH067620A - Cassette type multistage filter - Google Patents

Abstract

PURPOSE:To lower pressure loss, to increase the dust collecting property, to prolong the service life of a filter and to improve attachability and detachability by providing multistage structure superposed with a rugged formed filters consisting of nonwoven fabrics sheet respectively having specified properties. CONSTITUTION:A nonwoven sheet 1 of 5-50mum average fiber diameter, 0.05-0.50g/cm<3> bulk density and >=70% breaking extension at 100 deg.C, a formed filter 2 made of the sheet 1 and rugged with 3-50mm height, a nonwoven sheet 3 made of an extremely fine nonwoven fabric of 0.5-0.6mum average fiber diameter and 0.05-0.5g/cm<3> onto whose one surface or onto whose both surfaces a fiber sheet having 10-60mum average fiber diameter and 0.05-0.50g/cm<3> bulk density is laminated, a formed filter 4 rugged with 3-50mm high and a sheet-shaped material 5 stuck with a powdery deodorant are succeedingly superposed from the upper stage and the end surface and a frame are frame-worked by an adhesive or formed foam parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an air cleaner, a vacuum cleaner,
It is a multi-stage filter that can be used as a filter for automobiles. More specifically, the present invention has a multi-stage structure with a concave-convex shaped filter, and therefore has a low pressure loss, a high dust removal property, a long filter life, a cassette shape, and a cassette type which is excellent in detachability. Regarding multi-stage filters.

[0002]

2. Description of the Related Art Heretofore, as a filter, particularly a filter for an air cleaner, JP-A-60-150812 discloses an air cleaner filter in which a powdery adsorbent is coated with an electret filter having a large fineness. There is.

As a filter utilizing an electret filter, Japanese Patent Publication No. 56-47299 discloses a filter in which electric polarization is oriented randomly dispersed in an electretized fiber sheet.
Japanese Patent No. 241519 discloses an electret filter in which the direction of electric polarization is oriented in the thickness direction of the sheet.

The conventional electretized filter is widely used because of its high dust removing property. However, it is known that the surface charge is attenuated when the collection of particles is advanced to some extent. In particular, the effects of cigarette tar and the like are significant.

Further, in order to improve the collection performance of fine particles, an ultrafine fiber filter has been used. The ultrafine fiber filter has a high dust removal property, but has problems such as high pressure loss and surface filtration phenomenon, which easily causes clogging and a short filter life.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have studied how to make use of the high dust removal performance of an elecroletized filter, prevent the surface charge from decaying in the state of low pressure loss, and prolong the filter life. The present invention has been completed.

[0007]

[Means for Solving the Problems] That is, the present invention is: (a) Bulk density of 0.05 to 0.
Breaking elongation at 50 g / cm ³ under heating at 100 ° C is 70%
The non-woven sheet as described above is further provided with a molding filter (A) having a height of 3 to 50 mm and an uneven shape,
(B) Bulk density of 0.05 having an average fiber diameter of 0.5 to 6.0 μm
To 0.5 g / cm ³ of ultrafine nonwoven fabric, and one or both sides of the ultrafine nonwoven fabric having an average fiber diameter of 10 to 60 μm and a bulk density of 0.05.
~ 0.50 g / cm ³ of fiber sheets are laminated and height 3 ~
From the upper layer, (a), at least one stage of a molded filter (B) having an uneven shape of 50 mm and (c) at least one stage of a sheet-like material (C) to which a powdery deodorant is attached,
This is achieved by a cassette-type multistage filter, which is superposed on (b) and (c) and whose end face and frame are frame-processed with an adhesive or a foam molded product.

The embodiments of the present invention will be shown and specifically described below. FIG. 1 is a schematic sectional view of a cassette type multi-stage filter of the present invention. FIG. 2 shows a perspective view thereof. Figure 3
Shows a frame for framing the filter shown in FIGS.

In FIG. 1, a non-woven sheet 1 is a fibrous sheet for the purpose of collecting large particles and checking the degree of dirt on a filter. The concavo-convex shaped filter 2 is a shaped filter A formed by forming a non-woven sheet into a concavo-convex shape, whose main purpose is to collect relatively large particles.
Indicates.

The non-woven sheet 3 is made up of an uneven molding filter 2,
4 is a fiber sheet having a role of a separator. The concavo-convex shaped filter 4 is a main filter intended for collecting relatively fine particles, and is a concavo-convex shaped filter B obtained by laminating an ultrafine nonwoven fabric and a fiber sheet. The deodorant-attached sheet 5 is a sheet-like material to which a powdery deodorant is attached.

As described above, the cassette type multi-stage filter of the present invention has a structure in which particles are collected in stages, the load of the electretized main filter is reduced, and the attenuation of surface charge fibers is reduced. It is a thing.

In the case of the one-stage electret filter which has been widely used recently, it has an excellent ability to collect fine particles, but the state of accelerating the surface charge attenuation of the fiber is accelerated and the filter life is shortened. . Further, it is known that the structure for expanding the filtration area can reduce the pressure loss and prolong the life of the filter.

Therefore, the cassette type multistage filter of the present invention has been reached based on the idea that a molding filter for collecting particles stepwise can be efficiently constructed in a multistage structure.

Particularly, it is possible to improve the deodorizing effect by carrying out the odor after collecting the fine particles. Further, since it is necessary to replace the filter agent after it has been used for a certain period of time, it is necessary that the filter agent can be easily replaced. The filter of the invention, framed in the set, also serves this purpose.

The molded filter (A) of the present invention has an average fiber diameter of 5 to 50 μm and a bulk density of 0.05 to 0.50 g / cm ^3.
Composed of non-woven sheets. The non-woven sheet is one or two of short fibers such as polyolefin fibers, polyester fibers, polyamide fibers, polyacrylic fibers, polyethylene / polypropylene composite fibers, heat-fusible fibers and adhesive fibers, and long fibers.
A web obtained by mixing and laminating seeds or more can be obtained by a known method such as a needle punch method, a spunbond method, or a wet columnar flow method for obtaining a non-woven sheet.

The molded filter (A) of the present invention needs to have an average fiber diameter of 5 to 50 μm and a bulk density of 0.05 to 50 g / cm ³ . 5 μm
Below, clogging due to the collection of particles is likely to occur. On the contrary, if it is 50 μm or more, the particle collecting property becomes poor. When the bulk density is 0.05 g / cm ³ or less, the fiber space becomes large, the particle collecting property is poor, and the shape retention after molding is poor. On the contrary, at 0.50 g / cm ³ or more,
The fiber space is too dense and particles are easily clogged, resulting in high pressure loss.

In the present invention, since the non-woven sheet is formed into a concavo-convex shape for the purpose of enlarging the filtration area, it is necessary that the non-woven sheet is easily formed. Molding process is 60 ℃ ～ 2
In a temperature atmosphere of 00 ° C., it can be formed by a pleating machine, a press molding machine or the like by a folding method, an uneven roll method, or the like. Therefore, as a characteristic indicating that the material is easily deformed under heating, the breaking elongation is 70% or more under heating at 100 ° C. For example, an aromatic polyester long-fiber nonwoven fabric having a single yarn breaking elongation of 100% or more is
Because it has excellent heat resistance, moldability, strength, shape retention, etc.,
It is preferably used for the nonwoven sheet of the present invention.

The molded filter (A) of the present invention is
It is formed into an uneven shape having a height of 3 to 50 mm. Height 3
If it is less than or equal to mm, the effect of enlarging the target filtration area of the uneven shape is small. On the other hand, if the thickness is 50 mm or more, the thickness becomes too large for the multi-stage structure, and the handleability becomes poor.

The molded filter (B) of the present invention is formed by laminating an ultrafine non-woven fabric and a fiber sheet and molding it into an uneven shape. The ultrafine nonwoven fabric has an average fiber diameter of 0.5 to 6.0 μm,
Bulk density of 0.05 to 0.50 g / cm ³ , and one or more polymers such as polyethylene, polypropylene, polyester, polyamide and polyurethane, and / or
Copolymer such as styrene-butadiene copolymer,
It is obtained by a melt blow method or the like.

The ultrafine nonwoven fabric plays an important role in determining the filter performance of the present invention. Therefore, the average fiber diameter is 0.5
The bulk density is 0.05 to 0.50 g in the range of up to 6.0 μm.
A range of / cm ³ is required. When it is 0.5 μm or less, the single fiber strength is low, the handleability is poor, clogging is likely to occur, and the pressure loss is large. On the other hand, if it is 6.0 μm or more, the dust removing property aimed at by the present invention cannot be obtained. Further, when the bulk density is 0.05 g / cm ³ or less, the fiber space becomes large and the handleability is poor, and when the bulk density is 0.50 g / cm ³ or more, the fiber space is too dense and easily clogged, resulting in a large pressure loss. Will be things.

The fiber sheet has an average fiber diameter of 10 to 60 μm.
m, bulk density of 0.05 to 0.50 g / cm ³ , short fibers such as polyolefin fibers, polyester fibers, polyamide fibers, polyvinyl chloride fibers, polyethylene-polypropylene composite fibers, heat-fusible fibers, adhesive fibers, Alternatively, one or more long fibers may be mixed and laminated to obtain a spun bond method, a needle punch method, or the like.

Average fiber diameter is 10 to 60 μm, bulk density is 0.0
A range of 5 to 0.50 g / cm ³ is required. 10 μm
In the following, clogging is likely to occur, and conversely, in the case of 60 μm or more, the particle collecting property is poor. Further, the bulk density is 0.
If it is less than 05 g / cm ^{3, the} ability to collect particles and shape retention will be poor, and if it is more than 0.50 g / cm ³ , clogging will occur easily and pressure loss will be large.

Then, after laminating the fiber sheets, they can be joined together to facilitate the molding process. As a joining method, there is a partial heat fusion joining method using an embossing roll, an ultrasonic welder, or the like, or a method of partially applying an adhesive agent and adhering.

The laminated sheet thus obtained is molded into a concavo-convex shape in the same manner as the molding filter (A).

The sheet-like material (C) to which the powdery deodorant of the present invention is attached is a fine powder of activated carbon, silica gel, food roots, leaves, trunks, etc., which adsorb odorous components It can be obtained by adhering it to a foam-molded article such as polyurethane foam and / or a non-woven fabric sheet together with a resin, a urethane resin, a Poval resin, and the like.

At this time, the amount of the adhesive and the ratio of the powder deodorant are related to the deodorant performance. Adhesive and deodorant are 1:
0.2 to 2.0 is preferable. Furthermore, the adhesion amount is 1 by weight.
0 to 30% by weight is less likely to cause clogging, and preferable performance can be obtained. The sheet material (C) is obtained by impregnating a foamed molded article and a non-woven sheet material with a mixed liquid of a deodorant and an adhesive, squeezing the product, and drying.

Then, the obtained molded filter (A),
(B) and the deodorant sheet material (C) are laminated to form a cassette-shaped framework. The frame is obtained by using paper, non-woven fabric, and plastic materials. What you need as a frame material is
It should be hard enough to handle. Further, when the frame is formed, it is necessary to integrate the end face portion with the frame by using an adhesive or a foam molding. If not integrated,
The deodorant and the like flow from the gap with low air resistance, and the desired filter performance cannot be obtained.

Hereinafter, the present invention will be described more specifically with reference to Examples. The method of measuring the characteristic values used in the present invention is shown below. Unit weight (g / m ² ); The weight of a 20 cm square sample is measured and converted into the unit weight. Bulk density (g / m ² ); The basis weight and thickness are measured with a dial gauge, and the weight per unit volume is determined. Strength / elongation: Measured with a tensile tester at a grasping length of 10 cm and a pulling speed of 20 cm / min while changing the ambient temperature.

Ventilation resistance: Ventilation resistance when the sample is aerated at 30 L / min. Collection efficiency (%) ； Use the sample with silica dust-containing air [5
[mg / m ³ ], the collection efficiency when aerating at a flow rate of 30 L / min. Filter life: 5 mg / m ³ of silica dust-containing air was continuously passed through the sample at a flow rate of 30 L / min, and 2
It is indicated by the time when the airflow resistance becomes double.

The present invention is illustrated in detail by the following examples, which do not limit the scope of the present invention.

[Example 1] Pore size of 0.25 m by the spunbond method
m, the number of holes is 1000, and the short spinneret is used.
Polyethylene terephthalate having an intrinsic viscosity of 0.75 at 0 g / min was spun at a melting temperature of 290 ° C. and a spinning speed of 1800 m.
A long fiber web with a basis weight of 100 g / m ² (single yarn breaking elongation 380%) was partially thermocompressed at a temperature of 75 ° C. (compression area ratio 18%) to obtain a sheet A.

Further, the sheet A was subjected to a felt calender heat treatment at a temperature of 100 ° C., and the nonwoven sheet 1 shown in FIGS.
Used for 3. Next, the base fabric 2 of FIGS. 1 and 2 is obtained by applying the sheet A to a single fiber web weight of 100 g / m ² (fiber length 75 m
m, average fiber diameter 25 μ) and a card web made of polyethylene-polypropylene composite fiber, and needle punch processing and felt calender heat treatment under the conditions of No. 40 needle and 100 punches / cm ² (weight per unit area 200 g / m ² , bulk density 0.15 g / cm ³ , 100
Elongation at break under heating at 270%). Then, it was molded into a concavo-convex shape having a height of 15 mm with a pleat processing machine to obtain a concavo-convex molding filter 2 in Figs.

In FIGS. 1 and 2, the concavo-convex forming filter 4 is shown.
Is an average fiber diameter of 1.7 obtained by the melt blow method.
μ, a bulk density of 0.16 g / cm ³ , and a basis weight of 30 g / m ² electret-processed polypropylene ultrafine non-woven fabric and the above-mentioned non-woven sheet are overlaid, and a height of 15 m is obtained by a pleating machine.
It was obtained by molding into an uneven shape of m.

1 and 2, deodorant-attached sheet 5
Was mixed with bovar resin and activated carbon, and impregnated into a 15 mm-thick urethane foam, squeezed and dried to obtain a deodorant filter 5.

The obtained sheet 5 was piled up as shown in FIG. 1 and fixed as shown in FIG. 3 so that air was not leaked from the periphery to the cassette type multi-stage filter of the present invention. As for the filter performance, the ventilation resistance is 1.
₂ mmH ₂ O, a collection efficiency of 98%, and a filter life of 50 hours or more were obtained, and a desired cassette type multistage filter having excellent filter performance was obtained. Further, the odor was also evaluated, and it was found that it had a deodorizing effect.

[0035]

[Comparative Example 1] The performance when only the concavo-convex shaped filter 2 in FIG. 1 was used as a filter had a ventilation resistance of 0.6 mmH.
₂ O, collection efficiency 8%, and poor dust removal. Also, there was no deodorizing effect.

[0036]

[Comparative Example 2] The performance when only the concavo-convex shaped filter 4 in FIG. 1 was used as a filter had a ventilation resistance of 1.1 mmH.
₂ O, collection efficiency 96%, filter life 18 hours. In particular, the filter had a short filter life and was not the object of the present application to have a long filter life. Moreover, the deodorizing effect was hardly obtained.

[0037]

COMPARATIVE EXAMPLE 3 The filter performance of only the deodorant-attached sheet 5 in FIG. 1 has a ventilation resistance of 0.3 mmH ₂ O and a collection efficiency of 3%, and the collection efficiency is poor. Further, although the deodorizing property was effective, it was not as effective as in Example 1.

[0038]

EFFECTS OF THE INVENTION Since the multi-stage structure collects particles stepwise, the load on the electret filter is reduced, and the attenuation of surface charge can be reduced. Since it has a molded filter structure with an expanded filtration area, it has low ventilation resistance, high dust removal, and excellent filter life. It is composed of a molded filter and a deodorant sheet, and has excellent deodorizing properties. Since the multistage filter has a cassette structure, the filter can be easily replaced. Because it has features such as air purifier, automobile,
It can be preferably used as a filter for a vacuum cleaner or the like.

[0037]

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a cassette type multi-stage filter of the present invention. FIG. 2 is a perspective view of the cassette type multi-stage filter of the present invention. FIG. 3 shows a frame for framing the shaped filter. A frame is shown.

[Explanation of symbols]

 One or three non-woven sheets. 2 (a) Concavo-convex forming filter 4 (b) Concavo-convex forming filter 5 Deodorant adhering sheet. 6 Framework.

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[Procedure amendment]

[Submission date] August 30, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Figure 3]

[Fig. 2]

Claims (1)

[Claims] 1. A non-woven sheet having an average fiber diameter of 5 to 50 μm, a bulk density of 0.05 to 0.50 g / cm ³ , and a breaking elongation of 70% or more under heating at 100 ° C. 3 to 50
(b) Bulk density of 0.05 having an average fiber diameter of 0.5 to 6.0 μm.
To 0.5 g / cm ³ of ultrafine nonwoven fabric, and one or both surfaces of the ultrafine nonwoven fabric having an average fiber diameter of 10 to 60 μm and a bulk density of 0.05.
~ 0.50 g / cm ³ of fiber sheets are laminated and height 3 ~
(A), (b), (c) from the upper layer, at least one stage of a molded filter (B) having an uneven shape of 50 mm and (c) at least one stage of a sheet-like material (C) to which a powdery deodorant is attached.
A cassette-type multi-stage filter, characterized in that the end face and the frame are framed with an adhesive or a foam molded product.