JPH05208110A - Filter material for air cleaner - Google Patents

Abstract

PURPOSE:To enhance air cleaner capacity by preventing the clogging of a filter material due to carbon and white smoke and enhancing air blow cleaning properties. CONSTITUTION:A nonwoven fabric layer having a multilayered structure and a density gradient is provided and an oil adsorbent or oil adsorbing fiber whose density becomes gradually low from the coarse layer 12 on an air inflow side positioned on the side of one end part in the thickness direction of the layer to the dense layer 14 on an air outflow side positioned on the side of the other end part in the thickness direction of the layer through a middle layer 13 is added to the nonwoven fabric layer. As the oil adsorbent, sepiolite or activated carbon is used and, as the oil adsorbing fiber, an activated, carbon fiber is used. White smoke is adsorbed on the air inflow side of the nonwoven fabric and carbon with a small particle size is adsorbed on the air outflow side thereof and the mixing of white smoke and carbon within the nonwoven fabric layer can be avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter medium for an air cleaner, and more particularly to a filter medium suitable for an air cleaner of an automobile internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as a filter medium used in this type of automobile air cleaner, the main purpose has been to prevent dust, carbon and the like from entering the engine when air is supplied to the engine. Non-woven filter media were commonly used.

In the case of a carburetor type engine, FIG.
As shown in (b), there is proposed an air element in which a filter medium 5 for an air cleaner is bent in a zigzag shape and fixed by a fixing plate 6 (Japanese Utility Model Publication No. 58-30571). As shown in FIG. 8 (a), this filter medium for an air cleaner comprises an organic fiber web 1 and a sheet 3 containing activated carbon fibers having a resin adhered to one side thereof. The carbon fiber layer 2 is sandwiched between the carbon fiber layer 2 and the laminated body, and the organic fiber web surface is arranged so as to face the air intake side.

[0004]

However, due to the increase in the number of vehicles owned in recent years, carbon, which is an organic substance in the exhaust gas emitted by the vehicles themselves, becomes the main component in the atmosphere, and especially when following the vehicle, carbon that is absorbed by the air cleaner is used. The quantity has also increased. Among them, the exhaust gas of diesel engines such as trucks mainly contains a large amount of carbon, and further contains white smoke, which is unburned diesel oil, at the time of engine start, cold mornings and winter.

When the white smoke is mixed with carbon, the carbon melts into oil and water and penetrates deeply into the pores of the filter medium, greatly promoting the clogging of the filter medium for the air cleaner, and the carbon sticks to the oil, so that the air blow cleaning property can be improved. Aggravates
It has the property of shortening the life of the air cleaner to ⅕ or less of that when there is no white smoke, and has significantly deteriorated the air cleaner performance.

Further, as in Japanese Utility Model Publication No. 58-30521, in a filter medium which uses activated carbon fibers to adsorb gasoline vapor, the activated carbon fibers are provided on the sheet 3 located on the clean side of the air cleaner. Carbon having a small particle size also adheres to the layer, and the phenomenon of promoting the clogging due to the mixture of white smoke and carbon and the phenomenon of deteriorating the air blow cleaning property cannot be escaped.

An object of the present invention is to solve the above-mentioned problems of the prior art, to promote the clogging of the filter medium due to carbon and white smoke, to suppress the deterioration of the air blow cleaning property, and to improve the air cleaner performance. To provide.

[0008]

In order to achieve the above object, the first invention is characterized by containing one of an oil adsorbent and an oil adsorbent fiber at least on the air inflow side of the nonwoven fabric layer. A second invention has a nonwoven fabric layer having a multi-layered structure and having a density gradient, wherein the nonwoven fabric layer is located on one end side in the layer thickness direction from the rough layer on the air inflow side to the other end in the layer thickness direction. It is characterized by containing one of the oil adsorbent and the oil adsorbent fiber, the density of which gradually decreases as it reaches the dense layer on the air outflow side located at. And 3rd invention has a nonwoven fabric layer which has a multilayered structure and has a density gradient, The rough layer of the air inflow side located in the one end side of the layer thickness direction is one end side of this rough layer in the layer thickness direction. It is characterized by containing one of an oil adsorbent and an oil adsorbent fiber whose density is gradually reduced from the air inflow side located at the position to the air outflow side located at the other end side in the layer thickness direction of the rough layer.

[0009]

In the first aspect of the present invention, the oil adsorbent or the oil adsorbing fiber contained on the air inflow side of the nonwoven fabric layer adsorbs the oil content such as white smoke, and the other parts have almost no adsorption of white smoke. Since mainly dust particles having a small particle size are adsorbed, the mixing of white smoke and dust becomes extremely small.

In the second invention, the adsorption of white smoke gradually decreases from the air inflow side to the air outflow side of the nonwoven fabric layer, and conversely, the particle size gradually increases from the air inflow side to the air outflow side of the nonwoven fabric layer. Adsorption of small dust and the like increases, and the mixing of white smoke and dust becomes extremely small.

In the third aspect of the invention, the white smoke is adsorbed by the oil adsorbent or the oil adsorbing fibers contained in the air inflow side of the rough layer on the air inflow side, and the white smoke is gradually increased toward the air outflow side of the rough layer. Adsorption of white smoke is reduced, and there is almost no adsorption of white smoke other than in the rough layer. Conversely, as the non-woven fabric layer moves from the air inflow side to the air outflow side, the adsorption of dust and other small particles gradually increases, and Very little mixing with dust.

[0012]

EXAMPLE FIG. 1 (a) shows one embodiment of the filter material for an air cleaner of the present invention, and FIG. 2 (a) shows another embodiment of the filter material for an air cleaner of the present invention. These air cleaner filter media include an upper layer 12 on the air inflow side located on one end side in the layer thickness direction of the nonwoven fabric layer, a middle layer 13, and an air outflow side located on the other end side in the layer thickness direction of the nonwoven fabric layer. It has a structure in which the lower layer 14 is laminated. The upper layer 12 is preferably a synthetic fiber, for example, a spunbond type fiber made of polyester fiber. The porosity of the fibers forming the upper layer 12 is 8
About 0% to 90% is desirable.

The middle layer 13 is preferably a synthetic fiber, particularly a mixed fiber of regenerated fiber and synthetic fiber. Rayon fiber is suitable as the recycled fiber in this case, and as the synthetic fiber,
Polyester fiber, acrylic fiber, polyamide fiber and the like are desirable. Among these fibers, for example, the mixing ratio of rayon fiber and polyester fiber is 30% to 60%.
%: 70% to 40% is preferable.

The lower layer 14 is preferably synthetic fiber, particularly a mixed fiber of regenerated fiber and synthetic fiber. Rayon fiber is suitable as the recycled fiber in this case, and as the synthetic fiber, polyester fiber, polyolefin fiber, acrylic fiber,
Polyamide fiber or the like is preferable. Among these fibers, for example, the mixing ratio of rayon fiber: polyester fiber: polyolefin fiber is 50% to 20%: 70% to 4
0%: 25% to 5% is preferable.

In order to form the fiber aggregate by laminating the upper layer 12, the middle layer 13 and the lower layer 14 on each other, for example, a needle punching method, a method of binding with a binder, etc. can be preferably adopted. The most preferable bonding method is the needle punching method, but a method of using a bonding agent can be applied within the range where the ventilation pressure loss of the filter medium is not reduced.

A filter medium is formed on the fiber assembly thus formed by the following three means (1) to (3). (1) An oil adsorbent or an oil adsorbing fiber is contained in the upper layer 12 on the air inflow side located on one end side in the layer thickness direction of the nonwoven fabric layer. (2) As shown in FIG. 1 (b), the oil adsorbent has a density that gradually decreases toward the upper layer 12, the middle layer 13 and the lower layer 14 on the air inflow side located on one end side in the layer thickness direction of the nonwoven fabric layer. Alternatively, an oil-adsorbing fiber is contained.
(3) As shown in FIG. 2B, the upper layer 12 is made to contain an oil adsorbent or an oil adsorbent fiber so that the density becomes gradually smaller from the air inflow side to the air outflow side of the upper layer 12.

The oil adsorbent is preferably sepiolite, for example, sepiolite or activated carbon produced in Turkey. Further, as the oil-adsorbing fiber, activated carbon fiber is suitable, and such activated carbon fiber includes acrylic fiber,
Activated carbon fibers made of rayon fibers, phenol resin fibers, pitch fibers and the like can be used.

In order to include an oil adsorbent such as sepiolite or activated carbon in the nonwoven fabric layer, a binder is used together with these oil adsorbents, and a solvent, for example, water is used to form a mixed solution having an appropriate concentration, The fiber assembly may be dipped in this mixed solution. The binder can be arbitrarily selected depending on the type of fiber and the like. For example, acrylic ester-vinyl acetate copolymer, acrylic ester-styrene copolymer, acrylic ester-EVA copolymer, acrylic ，
Acrylic ester-vinyl acetate or the like can be used.

In order to contain the oil-adsorbing fiber in the non-woven fabric layer, for example, a method of mixing activated carbon fiber in the non-woven fabric layer is suitable. In this case, in the case of the above method (1), the activated carbon fiber may be mixed only in the upper layer 12, and in the case of (2), the upper layer 12, the middle layer 13, and the lower layer 1
The amount of activated carbon fibers mixed may be gradually reduced as the number of 4 becomes 4. Further, in the case of the method (3), the mixed amount of the activated carbon fiber may be gradually reduced from the air inflow side of the upper layer 12 to the air outflow side of the upper layer 12.

Next, a specific manufacturing example of the embodiment shown in FIG. 1A will be described. In this embodiment, the fiber layer forming the upper layer 12 corresponding to the air inflow side of the filter medium has a fiber diameter of 0.7.
A spunbond type fiber layer made of polyester fiber having a denier of ˜3, a porosity of about 78% and a basis weight of 25 g / m ² was used. As the fiber layer forming the intermediate layer 13, a mixed fiber layer of 50% rayon having a fiber diameter of 1 denier and 50% polyester having a fiber diameter of 1.25 denier and having a basis weight of 50 g / m ² was used.

The fiber layer forming the lower layer 14 on the air outflow side is made of 50% rayon having a fiber diameter of 1 denier, 35% polyester having a fiber diameter of 1.25 denier, and 15% of a polyolefin having a fiber diameter of 1.5 denier. An amount of 40 g / m ² of mixed fibers was used. These three types of fiber layers were laminated into upper, middle, and lower three layers and bonded by a well-known needle punching method to obtain a fiber assembly. The thickness of the obtained fiber assembly was about 6 mm.

Next, Turkish sepiolite was used as the oil adsorbent, and an acrylic ester-vinyl acetate copolymer was mixed and used as the binder, and water was used as the solvent to form a binder having a concentration of 20%. The above-mentioned fiber assembly was impregnated with a mixed solution with an oil adsorbent by 175 g / m ² by a dipping method.

Thereafter, dry air having a temperature of 110 ° C. and a humidity of 10% is blown in a direction perpendicular to the surface side of the lower layer 14 (layer thickness direction) at a flow rate of 22 m ³ / min per 1 m ^{2 of the} lower layer 14 for 0.1 hour. Then the solvent was evaporated. This produced the filter medium. The thickness of this filter medium was 0.5 mm, and the porosity of the lower layer 14 was 88%. Also, the intermediate layer 13
Had a porosity of 90%, and the upper layer 12 had a porosity of 92%.

As a result, the oil adsorbent having the opposite density gradient was added to the entire density gradient type filter material. That is, FIG.
As shown in (b), the oil adsorbent was attached such that the density gradually decreased from the upper layer 12 (rough layer) on the air inflow side to the lower layer 14 (dense layer) on the air outflow side.

Next, the result of a test by an air cleaner using this density gradient type filter material for an air cleaner will be described. FIG. 3 is a partially cutaway sectional view showing a filter element using the filter material for an air cleaner of this embodiment, and FIG. 4 is an enlarged view of a main part of FIG. In FIG. 3, this filtering element 21
Is provided with a cylindrical portion formed by arranging the filter material 11 formed in a zigzag shape in an annular shape, and the ends of the cylindrical portion are supported by the element end plates 22 and 23, respectively.
The outer peripheral surface is covered with protectors 24 and 25.

FIG. 5 is a vertical sectional view of the air cleaner to which the filter element 21 having the above-mentioned structure is attached, and FIG. 6 is a sectional view taken along line AA of FIG. 5 and 6,
This air cleaner 31 includes an air cleaner casing 32.
A filter element 21 having a filter medium 11 therein is provided,
Air is introduced into the air cleaner casing 32 from the inlet 33, and the filter element 2 using the filter medium 11 is used.
After passing 1, the outlet 34 is discharged. In the figure, 35 is a support leg, 36, 38, 40.
Is a packing, 37 is a fixing screw, and 39 is a dust pan.

FIG. 7 shows the test results of the above-mentioned filter material for an air cleaner. After supplying white smoke to the air cleaner for a certain period of time, carbon dust is supplied to clog the air cleaner, and then air blow cleaning is performed. The life of the air cleaner is shown at the actual vehicle level by performing a test in which the operation of restoring and supplying white smoke again is repeated. As is clear from FIG. 7, in the air cleaner using the filter medium of this embodiment, the clogging curve and the air blow cleaning property are greatly improved as compared with the conventional product.

The above test results are considered to be due to the following reasons. Inlet 33 in air cleaner 31
More white smoke and carbon dust are sucked in and the filter element 2
Even if it adheres to No. 1, in the filter medium 11 of the above-mentioned filter element 21, since the oil adsorbent added on the air inflow side is large and the density of the oil adsorbent on the air outflow side (clean side) is low (the added amount is small), The upper layer (coarse layer) on the air inflow side adsorbs oil like white smoke, and the lower layer (dense layer) on the air outflow side captures carbon with a small particle size, which makes it difficult to mix white smoke and carbon. As a result, the problems of the prior art such as early clogging of the filter medium and deterioration of the air blow cleaning property are eliminated, and the life of the air cleaner can be greatly extended.

That is, in the density gradient type nonwoven fabric of the present invention, fine dust such as carbon passes through the coarse layer on the air inflow side of the filter medium 11 and is captured by the dense layer on the air outflow side, so that oil content such as white smoke is obtained. Is actively adsorbed in the rough layer on the air inflow side

As described in the above embodiment, since fine dust such as carbon adheres to almost the dense layer side in the density gradient type filter material of the present example, oil such as white smoke is positively applied on the coarse layer side. By adsorbing to the filter medium, the filter material can be quickly clogged and the air blow cleaning property can be improved. However, in the embodiment shown in FIG. 2, the oil adsorbent is applied only to the coarse layer, whereby the mixture of carbon and white smoke on the dense layer side is completely eliminated, and the above effect can be made more complete. The life of the air cleaner can be further extended as compared with the embodiment.

[0031]

According to the invention of claim 1, oil content such as white smoke is adsorbed on the air inflow side of the non-woven fabric layer, and at other portions,
Since white smoke is scarcely adsorbed and mainly dust having a small particle size is adsorbed, the mixture of white smoke and dust is extremely reduced, so that clogging of the filter medium can be prevented and the air blow cleaning property can be improved.

According to the second aspect of the invention, the adsorption of white smoke gradually decreases from the air inflow side to the air outflow side of the nonwoven fabric layer, and conversely, from the air inflow side to the air outflow side of the nonwoven fabric layer. Adsorption of dust or the like having a small particle size is increased and mixing of white smoke and dust is extremely reduced, so that clogging of the filter medium can be prevented and air blow cleaning property can be improved.

According to the third aspect of the present invention, the adsorption of white smoke gradually decreases from the air inflow side to the air outflow side of the coarse layer on the air inflow side, and almost all white smoke is adsorbed on the portions other than the coarse layer. On the contrary, as the non-woven fabric layer goes from the air inflow side to the air outflow side, the adsorption of dust and other small particles gradually increases, and the mixing of white smoke and dust becomes extremely small, so clogging of the filter medium can be prevented. The air blow cleaning property can be improved.

[Brief description of drawings]

FIG. 1 (a) is a vertical cross-sectional view showing an embodiment of a filter material for an air cleaner of the present invention, and FIG. 1 (b) is a graph showing a change in an oil adsorbent or an oil adsorbent fiber density in the filter material for an air cleaner shown in (a). Is.

FIG. 2A is a vertical cross-sectional view showing another embodiment of the filter material for an air cleaner of the present invention, and FIG. 2B shows a change in the oil adsorbent or the oil-adsorbed fiber density in the filter material for an air cleaner shown in FIG. 2A. It is a graph.

FIG. 3 is a partially cutaway perspective view showing a filter element using the filter material for an air cleaner of the present invention.

FIG. 4 is an enlarged view of a main part of FIG.

5 is a cross-sectional view showing an air cleaner to which the filter element of FIG. 3 is attached.

6 is a cross-sectional view taken along the line AA of FIG.

FIG. 7 is a graph showing the relationship between the carbon supply amount and the increasing resistance of the filter medium, showing the comparison between the conventional example and the present example.

8A is a partial cross-sectional view of a conventional filter medium for an air cleaner, and FIG. 8B is a perspective view of a filter element in which the filter medium of FIG. 8A is assembled.

[Explanation of symbols]

 11 Filter Material 12 Upper Layer 13 Middle Layer 14 Lower Layer 21 Filtration Element 22,23 End Plate 24,25 Protector 32 Air Cleaner Casing 33 Inlet 34 Outlet 35 Support Leg

Claims (3)

[Claims] 1. A filter medium for an air cleaner, wherein an air inflow side located on one end side in the thickness direction of the nonwoven fabric layer contains one of an oil adsorbent and an oil adsorbent fiber. 2. A non-woven fabric layer having a multi-layered structure and having a density gradient, wherein the non-woven fabric layer is located at one end side in the layer thickness direction from the rough layer on the air inflow side to the other end side in the layer thickness direction. A filter material for an air cleaner, comprising one of an oil adsorbent and an oil adsorbent fiber, the density of which gradually decreases as it reaches a dense layer on the air outflow side located at. 3. A non-woven fabric layer having a multilayer structure and having a density gradient, wherein a rough layer on the air inflow side located on one end side in the layer thickness direction is provided on one end side in the layer thickness direction of the rough layer. An air cleaner containing one of an oil adsorbent and an oil adsorbent fiber, the density of which gradually decreases from the located air inflow side to the air outflow side located on the other end side in the thickness direction of the rough layer. Filter media.