WO2005118112A1

WO2005118112A1 - Manufacturing method of an air-cleaning filter and air cleaning filter manufactured by the method

Info

Publication number: WO2005118112A1
Application number: PCT/EP2005/005463
Authority: WO
Inventors: Seonguk Cho
Original assignee: Carl Freudenberg Kg
Priority date: 2004-06-04
Filing date: 2005-05-20
Publication date: 2005-12-15
Also published as: KR20040053088A; KR100585614B1

Abstract

The present invention relates to a method of manufacturing an air-cleaning filter for a vehicle, using a filter media made of a non-woven fabric having a good dust holding capacity (DHC) and also a polyurethane frame. The filter media is cut uniformly into a desired width while slowly releasing the filter media wound around a ro11. Then, the filter media is pleated at regular intervals through a knife -pleating method or a rotary-pleating method. A non -woven fabric is coated with a hot-melt resin and adhered and cured to both edges of the pleated filter media, such that the spacing between the peaks of the pleated filter mediais stably maintained, and simultaneously the air-leakage through the edges of the filter media is prevented. Thereafter, polyurethane is foamed using a die mould to thereby produce an air -cleaning filter for cars.

Description

MANUFACTURING METHOD OF AN AIR-CLEANING FILTER AND AIR CLEANING FILTER MANUFACTURED BY THE METHOD

Technical Field

The present invention relates to a method of manuf cturing

an air -cleaning filter fo r a vehicle, in which a filter media

made of non -woven fabrics having a good dust holding capacity is

pleated at regular intervals of a desired width, the spacing

between the peaks of the pleated filter media is fixed and

stabilized by using an edge banding and a resin at both edges of

the pleated filter media, and a frame is formed by foaming

polyurethane capable of significantly improving the productivity

of the air -cleaning filter, and to an air -cleaning filter

manufactured by the method.

Background Art

Conventional techniques relevant to the present invention

will be described below. The car air -cleaning filter element

employs mainly a non -woven filter media and a paper filter media.

In case of the non -woven fabric filter media and the paper

filter media, 0.38m² and 0.7m² are used respective, and the case

of paper filter media consumes 1.8 times more. In the terms of dust collecting capacity, however, the non -woven fabric filter

media has 259g/element, and the paper filter media has

70g/element. The non-woven fabric filter media has a 3.6 times higher duct -collecting capacity. That is, this means that the

non-woven fabric filter media has a 3.6 times longer life time

than that of the paper filter media. The amount of dust to be

collected depends on the structure of the filter media, and the non-woven fabric filter media is more advantageous, as compared

with the paper filter media. Conventionally, in the case where a paper filter media is

pleated and molded using a polyurethane frame to thereby

fabricate a paper air -cleaning filter, its productivity is

approximately 700~800 filters per hour. When an air -cleaning filter using a non -woven fabric filter media is formed through

an insert injection frame (using a thermoplastic material) , the

productivity thereof is about 100-110 filers per hour. The case

of paper filter media has a higher productivity than that of the

non-woven fabric filter media. That is, in the case where the non -woven fabric filter

media having a higher dust collecting capacity is use s, it

requires much time and cost to forming the insert injection frame, and thus its productivity is low and its production cost is high. In case of the paper filter media, the productivity is

high because the frame is molded using urethane, but its dust collecting capacity is very low due to the characteristic of the

paper filter. These problems can be solved by introducing an

insert injection frame. That is, since the non -woven fabric

filter media made of synthetic fiber series materials (VP, PE, PP) is thicker and more resilient than the paper filter media

made of a pulp material, the insert injection frame can be used in order to pleat the non -woven fabric filter media at regular

intervals and maintain a constant spacing between the peaks of

the pleated filter media.

Disclosure of Invention

The present invention has been made in order to solve the

above problems occurring in the prior art, and it is an object

of the invention to provide a method of manufacturing an air cleaning filter for automobiles having a good dust collecting

capacity and an improved productivity, in which a filter media

made of non -woven fabrics having a good dust collecting capacity

is used, a frame is molded using polyurethane series materials

inexpensive and capable of signifi cantly improving the

productivity, the filter media made of non -woven fabrics is

pleated uniformly at desired intervals, a non -woven fabric or a

fabrics is coated with a hot -melt and adhered and cured to both edges (end portion) of the pleated filter media , or the both edges thereof are coated with the hot -melt and cured, thereby

maintaining the spacing between the peaks of the pleated filter media and thus stabilizing the pleated filter media, and then the frame is formed using polyurethane series material s

relatively inexpensive and capable of using a simple process.

Another object of the invention is to provide an air -cleaning

filter manufactured by the method of the invention.

In order to accomplish the above object, according to one

aspect of the inven tion, there is provided a method of

manufacturing an air -cleaning filter for a vehicle. In the

method of the invention, a filter media made of non -woven

fabrics having a good dust holding capacity is pleated at

regular intervals of a desired width, the sp acing between the

peaks of the pleated filter media is fixed and stabilized by

using an edge banding and a resin at both edges of the pleated

filter media, and a frame is formed by foaming polyurethane

capable of significantly improving the productivity of the air - cleaning filter. According to another aspect of the invention, an air-cleaning filter manufactured by the method is provided.

Brief Description of Drawings Further objects and advantages of the invention can be more fully understood from the fo llowing detailed description taken

in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a knife -pleating process according to

the invention; FIG. 2 illustrates an edge -banding process according to the invention; FIG. 3 illustrates a rotary-pleating process according to the invention; and

FIG. 4 illustrates an emboss-treating process using a

rotary-banding roll according to the invention.

Best Mode for Carrying Out the Invention The preferred embodiments of the present invention will be hereafter described in detail with reference to the accompanying

drawings .

The use and function of an air -cleaning filter manufactured

according to the invention will be described below. In case of

automobiles using an internal combustion engine, ext ernal air and fuel are appropriately mixed and injected into the inside of

the cylinder. The injected air is mixed with the fuel. The

mixing of the air with the fuel affects significantly the

performance of the engine. In particular, when impurities foreign particles contained in the air flown from outside are

introduced inside of the engine without filtration, the engine

may suffer from critical damages. To solve this problem, the air-cleaning filter manufactured according to the invention is

used for filtering and cleaning the air in -flowing into the

engine by installing it in that portion of the engine that the

external air is introduced through. The structure of this air cleaning filter for automobiles is composed of a filter media

and a frame. Actu al collection of dust takes places in the

filter media. The frame functions to pleat the filter media in

certain intervals and maintain the bent form of filter media so that the performance of the filter is retained for a long time

and leakage of the airfl ow from outside is prevented. As an

approach in order to solve the above problems in the art, the

present invention employs a non -woven fabric of synthetic fiber (VR, PE, PP) , which has an excellent dust collection capacity.

The frame is made of polyureth ane series materials. The invention has proposed a process for forming a polyurethane

frame in a simple and inexpensive way and in a short time. Also,

the present invention has provided a method of manufacturing an air-cleaning filter for automobiles in an inexpensive and high - productive way, and an air -cleaning filter manufactured

according to this method. The air -cleaning filter of the

invention is composed of a non -woven fabric and a polyurethane

frame and has an excellent capability of duct collecting. The constitutional means according to the invention will be

specifically described below. The process for manufacturing an

air-cleaning filter using a filter media made of non -woven fabrics is generally comprised of a pleating process and a process for f abrication a frame. In the pleating process, a

knife pleating machine and a rotary pleating machine is used for pleating non-woven fabrics or papers. The knife -pleating machine is composed of an unwinder, a width cutter, a pre -heater, a pleating knife, and a main heater or an oven. The pleating

process using a knife -pleating machine is composed of steps of

cutting into a desired width a filter media made of non -woven fabrics, passing them through a pre -heater to smooth the filter

media, then pleating them u sing a knife, and stabilizing the

pleated filter media using a main heater or an oven.

In order for the above pleated filter media to be adopted

as a car air -cleaning filter media, a process for manufacturing

a polyurethane frame is carried out. In the fra ming process

using polyurethane, a frame is manufactured by banding both

edges of the filter media, which is pleated by means of the

knife-pleating machine. As the edge member to be attached to

both edges, non -woven fabrics, papers or plate -like things are used. The edge member is cut such that its width is l~3mm

larger than the peak height of the pleated filter media. The cut

edge is wound around a roll and fixed in a position to have easy

access to the both edges of the pleated filter media. The pleated filter media is fit into a jig in order to maintain the

constant intervals of peaks. After that, the edge member is

coated with resin and adhered to the edge of the pleated filter

media for banding. Thereafter, as illustrated in FIG. 2, a hot - melt resin, which is melted in a hot -melt applicator, is sprayed through a hot -melt nozzle and coated evenly in the edge member. The edge member coated with the hot -melt resin is adhered to the both ends of the filter media fitted into the jig, before the

coated resin is cured. The edge member is uniformly stuck to

the both ends of the filter media by pressing using a small roll or other devices capable of exerting a pressure. Upon completion

of sticking the edge member, the filter media with the edge

member stuck t hereto is cooled in the air for a certain period

of time. When the hot -melt resin is cooled and cured, the adherence of edge member is stabilized, and thus the edge

banding process is finished. Here, in the case where the width

of the filter media is abov e 50mm, a rib is inserted in order

for the filter media not to sag by the force of air, or the

center of the filter media is coated with the hot -melt resin

using a nozzle, thereby preventing the occurrence of dead space in the filter media. As a method of inserting the rib, plastic

materials, hard board papers, aluminum or iron (SUS) , or the

like are made in a different shape and size, depending on the

shape of the peak (height, interval) , and inserted into the

center of the pleated filter media and then f ixed by foaming polyurethane. The dead space means a space, which fails to

collect dust. For example, the pleated filter media sags or

leans sideways by means of the air pressure when the air passes

through the filter, and this affects neighboring pleated filter medium to thereby make them sag or lean by a domino theory.

Therefore, the folded or contacted portions of the filter media, i.e., the dead space, fail to collect dust. In this way, if a dead space is generated in the filter media, its dust collect ing

capacity is decreased and loss of pressure is increased, so that

the filter performance is significantly deteriorated. After the

adhering of the edge banding of the pleated filter media is completed, an urethane foaming process is carried out, which is

a final step of the process for manufacturing an air -cleaning

filter frame. If the edge banding process is finished, the .

filter media pleated in regular intervals and fixed is produced.

A polyurethane frame is formed in the pleated filter media using a die mould, in order to prevent the deformation of the pleated

filter media, and air leak through a gap generated in the edge.

In the manufacturing of the frame, a die mould is required for

foaming and molding liquid polyurethane. The molding die is

composed of an upper and lower part and structured so as to

minimize deformation of the pleated filter media during the

molding process in order to provide a good filter performance.

In the manufacturing process, polyurethane is poured using a

urethane chute device through the groove of the lower die having a desired shape. Then, the pleated filter media is put into the

die poured with the polyurethane in such a manner that the edge -

banding portion with the hot -melt resin is oriented downwardly. Thereafter, the upper die is placed, in order to maximally

prevent deformation of the pleated filter media during the

foaming process. After the urethane foaming is completed and the

upper and lower die is removed, an air -cleaning filter is

produced for automobiles. Altho ugh the foaming of the

polyurethane may be carried out at room temperature, it is

advantageous to use an oven in order to promote the foaming rate .

It is appropriate that the temperature of the oven is maintained

in the range of 50~100 °C. In the process f or manufacturing the frame, polyurethane or an elastic material is employed since

using these materials does not require any separate packing

material for preventing the air -leakage, so that the •

manufacturing cost can be reduced and the production speed can

be increased. The gap between the peaks of the pleated filter

media is within a range between 2 mm and 5mm.

Nest, the rotary pleating mode will be explained. The

rotary pleating machine is composed of a pre -heater, a pleating

roll, and a main heater. The process promotes pleating

workability by softening the filter media in the pre -heater.

The pleating roll is composed of an upper and lower roll. The

upper and lower roll has a raised portion and a depressed

portion alternately engraved and having a d esired pleating

height. While the filter media passes, a negative imprint and a

positive imprint having a determined peak height are generated. While passing the main heater, the speed is lowered, and thus due to the lowered speed, a pleating is generate d by means of

the negative and positive imprints formed above. The heat of

the main heat stabilizes the pleated form . An advantage of the

rotary pleating is its higher speed, and a disadvantage thereof is its difficulty in pleating a wider width.

As illustrated in FIG. 3, the rotary pleating machine is

constituted of an unwinder, a pre -heater, a pleating roll, and a

hot-melt applicator. The rotary pleating process is composed of

step of a) passing a filter media through the pre -heater to

soften it, b) fo rming a pattern in the filter media having an

emboss and a desired peak height by passing the filter media

through the pleating roll engraved with a pleating line and

various patterns, and c) pleating the filter media along the imprints pressed while passing the pleating roll. Both edges of the pleated filter media are coated with a hot -melt resin, which

is made by melting thermoplastic resin such as e thylene-vinyl

acetate (EVA), polyester, Polyamide. The both edges of the

filter media are completely adhered by the coated hot -melt resin,

and thus a pleating of the filter media is finished, without air-leakage through the both edges thereof. The pleating roll

is composed of an upper and lower roll . Since the pleated width

is relatively narrow within 4mm, the resin coated on the edge of

the pleated filter media enables adhering of the edges of the pleated filer media while maintaining the constant gap between

the peaks thereof. Also, the leakage of unfiltered air is prevented by sticking the both edges of the filter media.

The filter media finished with the above rotary pleating

machine is provided with a frame, which is manufactured using

polyurethane and a die mould. The method of manufacturing a

frame is the same as that used in the knife pleating. The operational effect of the frame manufactured the same method is also identical .

[Example 1]

A filter media made of non -woven fabrics is used as the filter media. The non -woven fabric filter media has a weight of

50 to 500g/m², a thickness of 0.5 to 7.0mm, and a permeability of

20 to 300cc/cm ²/sec. Although the non -woven fabric filer media

may be pleated by a rotary pleating mode or a knife -pleating mode, the knife -pleating mode is employed in the example 1. In

the pleating process, the selected non -woven filter media is

hung on the unwinder, and the tension is lowered such that the

filter media is slowly and smoothly unwound and then cut in a desired constant width using a cutter. The cutting of the

filter media into a desired width is carried out in such a

manner that an pre -installed ruler or other measuring devices is

fixed at the position where the cuter is placed, and then the cutting of the filter media is carried out while passing it .

The shape of the cutter is preferred to be circular as shown in

FIG. 1. The cutting is partly carried out in the form of a dotted line, in stead of complete cutting, so that each width is

prevented from being disturbed during the pleating process. The

filter media finished with the cutting process passes the pre

heater and then is pleated, using a knife already -installed

conforming to the peak height to be pleated. The filter media

finished with the pleating process passes the main heater, in which a heat treatment is performed so as not to disturb the

pleating, thereby completing the pleating. Next, in order for

the pleated filter media to be applied as an air -cleaning filter

for a car, a frame is manufactured. In the framing process using

polyurethane, both edges of the filter media pleated by the

knife-pleating machine are banded with an edge member, and then

the frame is manufactured. The edge member to be adhered to the

both edges of the filter media may employ non -woven fabrics,

fabrics, papers or other plate -like materials. The edge member

is cut so as to have a wi dth of l~3mm larger than the peak

height of the pleated filter media and wound around a roll . As

illustrated in FIG. 2, the rolled edge member is fixed in the

position to have easy access to both edges of the pleated filter

media. The pleated filter media is fixed into a jig in order to

maintain the constant peak spacing thereof. Then, the edge member is coated with resin and banded to the edge of the filter media. As depicted in FIG. 2, the hot -melt resin melted in the

hot-melt applicator is sprayed thro ugh a nozzle and evenly

coated on the edge member. The edge member coated with the hot melt resin is adhered to the both edges of the filter media

fitted into the jig, before the resin is cured. The edge member

is evenly adhered to the both edges of the fi Iter media by

pressing it using a small roll or other devices capable of

exerting a pressure. The filter finished with the adhering

process is cooled in the air for a certain period of time, and then the resin is cooled and cured, so that the edge banding

process is finished by stabilizing the adhering by the edge

member. Here, in the case where the width of the filter media is

above 50mm, a rib is inserted in order for the filter media not to sag by the force of air, or the center of the filter media is

coated with the hot -melt resin using a nozzle, thereby

preventing the occurrence of a dead space in the filter media.

As a method of inserting the rib, plastic materials, hard board papers, aluminum or iron (SUS) , or the like are made in a different shape a nd size, depending on the shape of the peak

(height, interval) , and inserted into the center of the pleated

filter media and then fixed by foaming polyurethane. The dead

space means a space, which fails to collect dust. After the edge banding process of t he pleated filter media is completed, a urethane foaming process is carried out, which is a final step of the process for manufacturing an air -cleaning filter frame. If the edge banding process is finished, the filter media

pleated in regular intervals an d fixed is produced. A

polyurethane frame is formed in the pleated filter media using a

die mould, in order to prevent the deformation of the pleated filter media, and air leak through a gap generated in the edge.

In the manufacturing of the frame, a die mould is required for

foaming and molding liquid polyurethane. The molding die is

composed of an upper and lower part and structured so as to

minimize deformation of the pleated filter media during the

molding process in order to provide a good filter perf ormance .

In the manufacturing process, polyurethane is poured using a

urethane chute device through the groove of the lower die having

a desired shape. Then, the pleated filter media is put into the

die poured with the polyurethane in such a manner that the edge- banding portion with the hot -melt resin is oriented downwardly.

Thereafter, the upper die is placed, in order to maximally

prevent deformation of the pleated filter media during the

foaming process. After the urethane foaming is completed and the upper and lower die is removed, an air -cleaning filter is

produced for automobiles. Although the foaming of the

polyurethane may be carried out at room temperature, it is

advantageous to use an oven in order to promote the foaming rate . It is appropriate that the temperature of the oven is maintained

in the range of 50-100 °C. In the process for manufacturing the frame, polyurethane or an elastic material is employed since using these materials does not require any separate packing

material for preventi ng the air -leakage, so that the

manufacturing cost can be reduced and the production speed can

be increased. The gap between the peaks of the pleated filter media is within a range between 2 mm and 5mm.

[Example 2]

Example 2 relates to a method of manufa cturing an air -

cleaning filter using a rotary pleating machine, which uses a filter media made of non -woven fabrics having a good dust

collecting capacity and a polyurethane frame capable of

significantly improving the productivity, and to a polyurethane

frame air -cleaning filter manufactured according to the above method. In this method, the filter media made of non -woven

fabrics is cut into a desired width to be used. Dissimilar to

the knife -pleating process in the example 1, the pleating

process does n ot carry out cutting. In pleating, the pleating

roll is most important. The pleating roll is composed of an upper and lower roll . The pleating roll has a positively engraved portion (a raised portion) and a negatively engraved

portion (depressed portion ) . These engraved portions have two functions. First, the roll has peaks engraved in certain

regular intervals in order to pleat with a peak height to be

pleated, and the engraved portion is made in one of the rolls.

The engraved portion is made in a st raight-line form over the

roll. In the other roll, a depressed portion may be made, or none. One the roll may have a negatively engraved portion and

the other may have a positively engraved portion. In this way,

the engraved portions are repeatedly form ed along the

circumferential surface of the roll at regular intervals. When a filter media having a constant width is passed between the

peaks of above -engraved roll, an emboss engraved with a raised

portion and a depressed portion is formed in the surfac e of the

filter media. In order to form the pleating or bending in easier manner, at the center portion between the embosses, one

of the roll is positively engraved and the other roll is

engraved negatively, so that the spacing between the peaks is

maintained constantly, after the pleating of the filter media is

completed by the pleating roll. As the filter media, similar to

the example 1, a filter media made of non -woven fabrics is used.

The filter media is transferred from the unwinder and softened

through the pre -heater, and then passes the pleating roll. At this time, a pattern presenting a pleating width is formed in

the filter media according to the engraved form of the roll .

Also, an emboss for maintaining the spacing between the peaks is formed in the filter media. A hot -melt resin is coated in both edges of the filter media. The constituent of the coated hot

melt includes e thylene-vinyl acetate (EVA), polyester, Polyamide,

and the like. The advancing speed of the filter media coated

with the hot-melt resin is lowered to pleat the filter media at

regular intervals according to the pleating pattern. The hot

melt resin coated on the both edges of the pleated filter media

is stuck and cured, so that air -leakage through the both edges

of the pleat ed filter media can be prevented, and the pleating pattern formed at the regular interval is maintained. The width

between the peaks of the pleated filter media is relatively narrow within 4mm, and thus the air -leakage through the edges of

the pleated fil ter media can be prevented by means of the

adhering of the resin coated on the both edges of the pleated filter media. In the case where the width of the pleated filter

media is larger than 50mm, a hot -melt resin is coated in the

center of the pleated fil ter media in order to fix the spacing

between the peaks of the pleated filter media, thereby

preventing generation of dead space, which may be occurred when the air -cleaning filter is used. As another method of

preventing the dead space, similar to the ex ample 1, a rib is

inserted and fixed by molding with a polyurethane frame. The

manufacturing process of the polyurethane frame is carried out

in the same manner as in the example 1. Industrial Applicability

As described above, according to the invention, a filter media made of non -woven fabrics having a good dust collecting

capacity is used, and a frame is molded using polyurethane

series materials capable of significantly improving the productivity, along with a reduced manufacturing cost. That is,

the filter media made of non -woven fabrics is pleated uniformly

at desired intervals. A non -woven fabric or a fabrics is coated

with a hot -melt and adhered and cured to both edges (end

portion) of the pleated filter media, or the both edges thereof

are coated with the hot -melt and cured, thereby maintaining the

spacing between the peaks of the pleated filter media and thus

stabilizing the pleated filter media. Then the frame is formed

using polyurethane series materials relatively inexpensive and

capable of u sing a simple process. Therefore, a good dust collecting capacity can be achieved, and the productivity can be

significantly improved, together with a reduced manufacturing

cost . While the present invention has been described with

reference to the particu lar illustrative embodiments, it is not to be restricted by the embodiments but only by the appended

claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the

scope and spirit of the present invention.

Claims

What Is Claimed Is:

1. A method of manufacturing an air -cleaning filter for

automobiles, in which a filter media made of non -woven fabrics

is used and a frame is molded using polyurethane, the method

comprising steps of : a) pleating the filter media made of non -woven fabrics,

in which the filter media made of non -woven fabrics is cut using

a cutter so as to have a constant width, and pleated at regular

intervals using a pleating machine, or pleated by engraving an

emboss to maintain a constant spacing between peaks; b) stabilizing the pleated filter media, in which an

edge member is adhered to both edges of the pleated filter media

by coating a hot -melt resin and cured, or only the hot -melt

resin is adhered and cured; and c) molding a frame made of polyurethane series materials

using a desired die mould and using the pleated and stabilized

filter media through the adhering and curing of the edge member

with the hot -melt resin, or through the adhering and curing of

the hot-melt resin only.

2. The method according to claim 1, wherein the pleating

machine for pleating the filter media made of non -woven fabrics includes a knife -pleating machine or a rotary -pleating machine capable of engraving an emboss.

3. The method according to claim 1, wh erein the filter

media made of non -woven fabrics has a weight of 50 to 500g/m ², a

thickness of 0.5 to 7.0mm, and a permeability of 20 to 300cc/cm²/sec.

4. The method according to any one of claims 1 to 3 ,

wherein the hot -melt resin is selected from e thylene-vinyl acetate, polyester, or Polyamide, according to applications.

5. The method according to claim 4 , wherein the edge

member material includes non -woven fabrics, fabrics, or papers,

and the edge member is cut l~3mm larger than the peak height of the pleated filter media.

6. The method according to any one of claims 1 to 3 ,

further comprising a step of inserting a plastic material, a

hard board paper, aluminum, iron (SUS) , or the like sparsely into the pleated filter media such that the pleated filter media

is prevented from sagging or leaning by means of air pressure,

after the adhering and curing step of the hot -melt resin is

completed and before the frame is molded with polyurethane, the form of the plastic material, the hard board paper, the alumin um,

the iron (SUS) , or the like being different according to the

height and spacing of the peak.

7. The method according to claim 6, further comprising a

step of coating and curing a hot -melt resin in the center

portion of the pleated filter media, instea d of inserting a rib,

such that the pleated filter media is prevented from sagging or

leaning by means of air pressure, after the adhering and curing

step of the hot -melt resin is completed and before the frame is

molded with polyurethane.

8. An air -cleaning filter for automobiles, in which a

filter media made of non -woven fabrics is used and a frame is

molded using polyurethane, the air-cleaning filter comprising: a) means for pleating the filter media made of non -woven

fabrics, in which the filter media made of non -woven fabrics is

cut using a cutter so as to have a constant width, and pleated

at regular intervals using a pleating machine, or pleated by

engraving an emboss to maintain a constant spacing between

peaks ; b) means for' stabilizing the pleated filter media, in

which an edge member is adhered to both edges of the pleated filter media by coating a hot -melt resin and cured, or only the

hot-melt resin is adhered and cured; and c) means for molding a frame made of polyurethane series

materials using a desired die mould and using the pleated and

stabilized filter media through the adhering and curing of the

edge member with the hot -melt resin, or through the adhering and

curing of the hot-melt resin only.

9. The air-cleaning filter according to claim 8, wherein

the pleating machine for pleating the filter media made of non

woven fabrics includes a knife -pleating machine or a rotary

pleating machine capable of engraving an emboss.

10. The air-cleaning filter according to claim 8, wherein

the filter media made of non -woven fabrics has a weight of 50 to

500g/m², a thickness of 0.5 to 7.0mm, and a permeability of 20 to

300cc/cm²/sec.

11. The air -cleaning filter according to any one of

claims 8 to 10, wherein the hot -melt resin is selected from

ethylene-vinyl acetate, polyester, or Polyamide, according to

applications .

12. The air -cleaning filter according to claim 11,

wherein the edge member material includes non -woven fabrics,

fabrics, or papers, and the edge member is cut l~3mm larger than

the peak height of the pleated filter media.

13. The air -cleaning filter according to any one of

claims 8 to 10, further comprising means for inserting a plastic

material, a hard board paper, aluminum, iron (SUS) , or the like

sparsely into the pleated filter media sue h that the pleated

filter media is prevented from sagging or leaning by means of

air pressure, after the adhering and curing step of the hot -melt

resin is completed and before the frame is molded with

polyurethane, the form of the plastic material, the har d board

paper, the aluminum, the iron (SUS) , or the like being different

according to the height and spacing of the peak.

14. The air -cleaning filter according to claim 13,

further comprising means for coating and curing a hot -melt resin

in the center por tion of the pleated filter media, instead of

inserting a rib, such that the pleated filter media is prevented

from sagging or leaning by means of air pressure, after the

adhering and curing step of the hot -melt resin is completed and

before the frame is molded using polyurethane.