KR101013158B1 - Filtering material for filter and method of preparing thereof - Google Patents

Abstract

The present invention relates to a filter medium for a filter and a method for producing the same, in particular a substrate having a porous structure; Porous foam resin coating layer comprising a plurality of pores bonded on the plane of the substrate; And it relates to a filter medium and a method for producing the filter, characterized in that one end comprises a pile layer consisting of a plurality of short fibers fixed on the porous foam resin coating layer.

According to the present invention, the fine dust generated in the field of incinerator, steel, powder industry, cement industry, etc. can be effectively removed not only by mechanical filtration through multi-layer filtration but also by electrostatic filtration. It can be used for various applications such as pre-filters, pocket filters, cartridge filters, cartridge filters, automobile air cleaner filters, and water treatment filters.

Filter, flocking, filter media

Description

Filter medium and its manufacturing method {FILTERING MATERIAL FOR FILTER AND METHOD OF PREPARING THEREOF}

1 is a schematic cross-sectional view showing the structure of one embodiment of the filter medium of the present invention.

FIG. 2 is a schematic side view of an apparatus for forming a foam resin coating layer including general pores according to an embodiment of the present invention.

Figure 3 is a schematic side view of the apparatus for forming a foam resin coating layer comprising a three-dimensional ultra-fine pores according to an embodiment of the present invention.

Figure 4 is a SEM photograph (x400) of the foam resin coating layer of the filter medium prepared as an embodiment of the present invention.

FIG. 5 is a SEM photograph (× 400) of a foam resin coating layer having an average diameter of 10 μm or less of the filter medium prepared as one embodiment of the present invention.

DESCRIPTION OF THE RELATED ART [0002]

1: Base material 2: Foam resin coating layer

3: pile layer

11: bubble generator 12: bubble coating machine

21: Stator 22: Rotor                 

23: rotor side pin 24: stator side pin

25: emulsion liquid supply pipe 26: air pressure supply pipe

27: crosslinking agent supply pipe

31 bubble supply nozzle 32 base material

33: resin foam 34: roller

35: coating knife 36: round edge

41: short fiber supply part 42: electric field forming part

43: transfer device 44: drying device

The present invention relates to a filter medium for a filter and a method of manufacturing the same. More specifically, the fine dust can be effectively removed not only by mechanical filtration through multilayer filtration but also by electrostatic filtration. It relates to a filter medium for filtering and a method for producing the same.

In many industrial processes, such as steel, cement, and powder or produce products in powder form, polluted air containing a large amount of dust is emitted, and air containing such polluted dust remains intact. Since heavy emissions can cause serious air pollution, all companies are required to purify the polluted air dust and release it into the atmosphere.                         

At this time, as a means for purifying the air containing the dust is a dust filter bag filter or cartridge filter, and the like, the filter medium for filtering the dust contained in the air inside the dust filter filter bag It is molded and mounted in a certain shape such as a bag shape or a bent shape.

As described above, the most important thing for the performance of the filter medium for dust collectors is that the pores should be fine, uniformly distributed, and high in porosity. In other words, it has excellent air permeability and minimizes the pressure loss due to the installation of the filter, and high filtration performance that filters even fine dust while passing only air well is required. In addition, the filter medium of the dust collecting filter is heat resistant, flame retardant, moisture permeable, waterproof, water repellent, Characteristics are required.

Accordingly, in the related art, a nonwoven fabric is used as the filter material. In the case of the nonwoven fabric, fine pores of the nonwoven fabric can remove fine dust, but the pores of the entire nonwoven fabric are made fine, so that the entire structure of the filter medium has a microporous structure. This makes it difficult to pass air, and the overall pressure difference applied to the nonwoven fabric itself is increased, so that the filtration efficiency, the filtration speed, and the like decrease, and the operating energy of the dust collector is consumed.

Therefore, the development of a filter medium having a multi-layer structure was made to solve the shortcomings of the nonwoven fabric. In other words, an acrylic resin or urethane resin solution using an organic solvent is coated on a silicon-treated and uneven paper using a knife, and then laminated together with a nonwoven fabric and calendered to transfer a film on paper to the surface of the nonwoven fabric. Although the method of manufacturing the filter medium for the dust collecting filter by the film laminating method for manufacturing the dust collecting filter by the pores of the above method has a very large pore size, it does not effectively remove the fine dust, working environment by using organic solvents There is a problem that it is poor and contains the risk of fire.

Another method is to prepare a foam by mixing the acrylic resin liquid and air, and then padding the foam onto the nonwoven fabric using a pad or a knife. However, this method merely provides strength between the nonwoven fibers and has a problem in that the foam structure is broken by the physical force of the knife or the pad itself, so that the three-dimensional foam structure cannot be formed on the surface of the nonwoven fabric.

Accordingly, a technique of injecting air into an emulsion liquid mainly containing resin to generate a resin foam and coating it on the surface of the nonwoven fabric by using a foam coating machine has been introduced. There is a problem that can not be filtered. In addition, in order to solve this problem, a filter including a three-dimensional ultra-fine pores of Patent Application No. 10-2002-7373 previously filed for the formation and maintenance of fine bubbles and a method of manufacturing the same have been proposed. However, with the development of the industry, more and more fine dusts are generated, and in order to improve the environmental protection and working environment, there is a problem to efficiently collect and remove the finer dusts.

In order to solve the problems as described above, the present invention is a filter medium for the filter that can be applied to various types of filters, as well as to efficiently remove fine dust without requiring a high differential pressure due to low pressure loss when passing through the filter medium. And it aims to provide the manufacturing method.

Another object of the present invention is to provide a filter medium and a method for producing the filter that can remove even fine dust more efficiently by applying a mechanical filtration method and an electrofiltration method together.

Still another object of the present invention is to provide a filter material for a multilayer structure and its manufacture, which reduces the pressure loss due to the use of a filter by minimizing pore blockage by different pore sizes or by different filtering means. It is an object to provide a method.

In order to achieve the above object, the present invention

A substrate having a porous structure;

Porous foam resin coating layer comprising a plurality of pores bonded on the plane of the substrate; And,

One end provides a filter medium for a filter comprising a pile layer composed of a plurality of short fibers fixed on the porous foam resin coating layer.

Also,

a) preparing a resin foam to produce foam by stirring the emulsion in a bubble generator;                     

b) a resin foam coating step of coating the produced foam on a substrate;

c) forming a pile layer by flocking short fibers to the coating layer; And,

d) a drying step of drying the substrate coated with the resin foam and the pile layer formed

It provides a method of manufacturing a filter medium for a flocked filter comprising a.

Hereinafter, the present invention will be described in detail.

The filter medium for a filter of the present invention includes a porous foam resin coating layer including a substrate having a porous structure, a plurality of pores bonded on a plane of the substrate, and one end of the plurality of short fibers fixed on the porous foam resin coating layer. Has a configuration that includes a file layer that is configured.

As shown in FIG. 1 as a schematic diagram of an embodiment of the present invention, the substrate serves as a support for the filter medium, has large pores, high porosity, reduces the differential pressure with respect to the air passing through the filter medium, and minimizes the pressure loss. . Therefore, since such a function requires high porosity, it has a porous structure including a plurality of pores therein. The substrate may include a nonwoven fabric and a woven fabric having a porous structure. Preferably, the nonwoven fabric is preferable in terms of ease of manufacture, porosity, and pore size control. In addition, the pores of the substrate is preferably larger than the pores of the foam resin coating layer in order to prevent the pressure loss of air passing through the filter medium.

The resin of the foam resin coating layer applied on the substrate may be any resin capable of forming bubbles (bubbles) through air injection and stirring, and preferably, in consideration of the harmlessness and ease of manufacture of the human body, a water-soluble resin is preferably used. The water-soluble resin may include an acrylic resin, NBR latex, SBR latex, natural latex, silicone rubber, water-soluble urethane, melamine resin, or fluorine-based resin.

In addition, various types of fillers may be included in order to improve mechanical properties or impart functionality to the resin. Preferably, the filler may be a general filler such as talc, Al (OH) ₃ , TiO ₂ , silica, or mica powder. And functional fillers such as PTFE powder, conductive carbon, or graphite. In addition, a foaming agent, foam stabilizer (foaming agent), or a dispersing agent for forming and maintaining the foam may further include a thickener, a crosslinking agent, or a binder.

Since the foam resin coating layer is a portion that is responsible for filtration of substantially fine dust of the filter medium, the foam resin coating layer has a porous structure having pores finer than that of the substrate. In addition, in order to minimize the pressure loss of the filtered air, the higher the porosity of the foam resin coating layer, the better the thickness of the foam resin coating layer within a range that does not impair filtration efficiency. Preferably the porosity is preferably 50 to 80% by volume and the thickness is preferably in the range of 100 to 300 ㎛. In addition, the size of the pores included in the foam resin coating layer is finer than the pore size of the substrate to have a pore of the appropriate size according to the size of the target dust to be filtered. Particularly, in the case of the high dust collector, since the fine dust must be removed, the size of the pores included in the porous foam resin coating layer is preferably an average diameter of 10 to 25㎛.                     

In addition, the upper surface of the porous foam resin coating layer is a pile layer consisting of a plurality of short fibers (pile, flock, or toe) one end is fixed on the porous foam resin coating layer Included.

As the short fiber, short fibers of various materials such as organic, inorganic, or metal materials may be used, and short fibers of various types may be used. In particular, when the filter medium for the filter of the present invention is used in the filter, in order to be made not only with mechanical filtration by short fibers but also with electrostatic filtration using electrostatic force, a material that exhibits dust and electricity in the air may be used. Preferably, polyester (PET), nylon (Nylon), viscose (Viscose), acrylic (Acrylic), polypropylene (PP), PVC, PVC: carbon fibers (Carbon fibers), carbon fibers, glass fibers (Glass) fibers), activated carbon fibers (ACF) or nylon / PET split composite yarn, and the like. In addition, the shape of the short fibers is preferably smaller in diameter than the pores in order to prevent pores of the foam resin coating layer. More preferably, the diameter of the short fibers constituting the pile layer is 0.5 to 3 denier.

In addition, the length of the short fiber may be used as the short fiber of the appropriate length according to the shape of the filter used in the filter medium, in particular, in the case of having a bag shape of the bag filter or when used in a bent shape in the cartridge filter Short fibers of appropriate length may be used in terms of the size of the dust to be desired, the aspect of filtration efficiency, and the fall prevention of short fibers. In particular, it is preferable to configure the fibers having a length of 0.3 to 2 mm for the fall prevention and filtration efficiency of the short fibers.                     

One end of the short fiber is fixed in various ways on the porous foam resin coating layer and the other end is free form, so that a plurality of parallel to each other is arranged. This allows the dust to pass through the pile layer consisting of a plurality of short fibers before approaching the foam resin coating layer and allows the pile layer to perform electrostatic filtration as well as mechanical filtration. The short fibers may be fixed to form a constant angle with the porous foam resin coating layer, and may have an appropriate angle to optimize the filtration efficiency according to the flow direction of the flow path in which the filter is used, in the case of ease of manufacture and universal specifications, Preferably it may be disposed perpendicular to the upper surface of the porous foam resin coating layer.

The filter medium for filters of the present invention may be used for filters of various uses and forms as a material responsible for filtration in the filter, and may be used directly in the filter or may be appropriately molded or chopped to fit the filter case or the cartridge mold. In particular, when the filter medium is used as the filter medium of the dust collecting filter, pre-filter, pocket filter, cartridge filter, filter for automobile air cleaner, water treatment filter, it is possible to manufacture an excellent filter having a high pressure and low pressure loss.

In addition, the present invention comprises the step of preparing a resin foam to produce a foam by stirring the emulsion in a bubble generator, and coating the produced foam on a substrate, and comprising the step of flocking the short fibers in the coating layer and then drying It features.

The manufacturing method of the present invention will be described in detail as follows.

Emulsion Preparation

Emulsion liquid used in the present invention can be used in various forms of resin, in particular, it is preferable to use a water-soluble resin as the main for convenience of use and operation, and here it is a filler, foaming agent, foam stabilizer (foaming agent), Or after mixing uniformly including a dispersing agent, it is preferable to use what thickened it with the thickener. In particular, in the present invention, the crosslinking agent and the binder in the emulsion solution components were added in the resin foam preparation step to solve the fluidity drop and the storage problem of the emulsion solution.

The water-soluble resin is preferably an acrylic resin, NBR latex, SBR latex, natural latex, silicone rubber, water-soluble urethane, melamine resin, or fluorine-based resin, the content is preferably 70 to 80 parts by weight.

As the filler, a general filler such as talc, Al (OH) ₃ , TiO ₂ , silica, or mica powder, and a functional filler such as PTFE powder, conductive carbon, or graphite may be used. Weight part is preferable.

As the foaming agent, sodium lauryl sulfate (SLS) or sodium dodecyl sulfate (SDS), which is a surfactant of a linear alkyl derivative having 12 carbon atoms, may be used, and the content thereof is 0.1 to 1.0 parts by weight. desirable.

As the foam stabilizer (foaming agent), ammonium stearate or silicone may be used, and the content thereof is preferably 1.0 to 10 parts by weight. The ammonium stearate system is excellent in microbubble generation, foam holding ability, and fluidity, but can weaken the coating strength of the foam coating product. Therefore, it is preferable to use the ammonium stearate and silicone system together to reinforce the coating strength. Do.                     

As said dispersing agent, the dispersing agent of a polycarboxylic acid polybasic salt component, or sodium polyphosphate can be used. In particular, sodium polyphosphate is effective at the time of dispersion of the emulsion liquid which can have a shock (shock) when the dispersion is excellent pH buffering effect is preferably 0.2 to 2.0 parts by weight.

As the crosslinking agent, it is preferable to use melamine-formaldehyde resin. Melamine resin not only acts as a crosslinking but also maintains fine bubbles due to the rapid progress of gelation during initial drying.In particular, the heavy weight filler prevents the foaming from sinking by its own weight to promote defoaming. . The content is preferably 0.2 to 2.0 parts by weight.

The binder may be a silicone binder, or a metal organic compound having an amino group, which reinforces the bonding force between the contact surface of the resin and the filler and prevents cracking between various materials having different thermal expansion coefficients. The content is preferably 0.2 to 2.0 parts by weight.

 The thickener is preferably an acrylic thickener, but due to its nature, the pH should be maintained as an alkali, so when the pH value is neutral or acidic, sodium alginate may be used, and the content thereof is preferably 0.2 to 2.0 parts by weight.

Resin bubble preparation stage

In this step, the prepared emulsion is stirred in a bubble generator to prepare a resin foam having an average diameter of various ranges according to the size of dust to be collected. In particular, in the case of advanced purification, it is preferable to produce foam having an average diameter of 1 to 5 µm.

The bubble generating device of the resin foam preparation step may use a known technique as a conventional bubble generating device, when the average diameter of the resin foam generates bubbles of 5 ㎛ or more foam generation as shown in an embodiment in FIG. An apparatus may be used, and a foaming apparatus such as the one shown in FIG. 3, which is preferably for an advanced purification apparatus, may be used. The bubble generator 11 of FIG. 3 is a stator 21 forming an outer wall, a rotor 22 at the center thereof, and is vertically fixed to the rotor 22, and a rotor having a pin thickness of 4 to 5 mm. Emulsion fixed to the pin 23 and the stator 21, the emulsion is installed on the stator side pin 24 having the thickness of the pin 4 ~ 5 mm and the top of the stator 21 in order to feed the raw material into the stator 21 It consists of the liquid supply pipe 25, the pneumatic supply pipe 26, and the crosslinking agent supply pipe 27.

The rotor side pin 23 and the stator side pin 24 have a thickness of 4 to 5 mm, and are fixed to the rotor 22 and the stator 21 at the center of the stator 21 by the number of about 250 to 350, respectively. The raw material supplied through the emulsion liquid supply pipe 25, the pneumatic supply pipe 26, and the crosslinking agent supply pipe 27 installed at the upper end of the stator 21 while the rotor 22 rotates at a speed of 50 to 500 rpm is mixed. To generate resin bubbles.

In the case of using the apparatus of FIG. 3 in this step, the prepared emulsion is poured into a bubble generator, blown with air, and stirred at a speed of 50 to 500 rpm to generate a resin foam. In addition, it is preferable to thin the thickness of the rotating pin in the bubble generator to about 4 to 5 mm.                     

In order to uniformly mix the emulsion solution, stirring is necessary, and heat is generated in the emulsion solution when stirring, and the crosslinking agent or the binder advances the crosslinking of the emulsion solution during the mixing process, thereby reducing the fluidity of the emulsion solution. . In addition, since the crosslinking agent and the binder are gradually crosslinked even at room temperature, not only the problem of lack of fluidity but also the storage problem of the emulsion liquid. Therefore, in the present invention, the crosslinking agent and the binder are not added during the mixing of the emulsion solution, but are introduced into a separate feed pipe during the production of the resin foam.

The pump for supplying the emulsion liquid to the bubble generator may be used a conventional pump, but it is possible to uniformly supply the set amount of the emulsion liquid regardless of the pressure inside the bubble generator or the supply pressure of the emulsion (change according to the level of the emulsion liquid, etc.). Preference is given to using monopumps which can.

The air pressure supplied to the bubble generator must be higher than the pressure inside the bubble generator, and preferably 2 kg / cm 2 or more higher than the pressure inside the bubble generator so that the air can be uniformly diffused into the emulsion within the bubble generator. If the air pressure supplied is lower than the pressure inside the bubbler, the emulsion liquid flows back to the air supply pipe, so care should be taken.

The bubble generator may form a smaller bubble size as the rotational speed is faster and the number of fine pins is larger. The rotational speed is preferably in the range of 50 to 500 rpm. If the rotation speed exceeds 500 rpm there is a problem that the stability of the emulsion can be lacking. In addition, it is preferable that about 600 pins are mounted on the rotor and the stator in the bubble generator.                     

The average diameter of the foam produced through this step is preferably at most 5 ㎛.

Resin Foam Coating Step

This step is a step of coating the produced resin foam on the substrate. The resin foam coating machine used in this step can be carried out by a known technique using a conventional coating machine, in particular, supplying a foam so that the resin foam can be evenly coated with a coating knife, preferably proceeds to the foam supply nozzle The foam is supplied at a high speed of reciprocating 5 to 30 times per minute in the transverse direction of the direction.

In this step, the resin foam, once produced, is applied to the surface of the substrate in a state in which the bubble shape is maintained so that the resin foam is laminated on the surface of the substrate as it is in a network structure. It is desirable to allow the stack to be 0.3 mm thick.

In addition, the resin foam of the coating knife is preferably given a round (round). In this case, not only does the resin foam accumulate and prevent the knife from being contaminated, but also the average diameter of the fine resin foam can be prevented from increasing due to excessive pressure from the knife.

The foam supply nozzle of the foam coater may be directly coated on the substrate as shown in Figure 2, preferably, as in the case of the embodiment shown in Figure 3, the foam coater 12 is generated in the foam generator 11 A foam supply nozzle 31 for supplying the resin foam 23 to the substrate 22, a roller 34 for conveying the substrate 32, and a resin foam 33 coated on the substrate 32 are provided. In order to coat uniformly, the substrate is positioned in a vertical direction on the upper part, and the part contacting the substrate is composed of a coating knife 35 having a round shape.

The foam supply nozzle 31 is installed in the transverse direction of the substrate 32 travel direction, and supplies the resin foam to the substrate 32 at a rate of 5 to 30 times of reciprocation per minute. The resin foam 33 supplied to the substrate 32 through the foam supply nozzle 31 is uniformly coated on the substrate by a coating knife 35 located outside the foam coater 12, and the coating knife 35 ) And the portion where the resin foam 33 supplied to the surface of the base material 32 is in a round 36 shape, so that the resin foam 33 accumulates on the coating knife 35 or the diameter of the resin foam 33 is coated. It can be prevented from becoming large due to excessive pressure of the knife 35. Therefore, using the nozzle shown in the said FIG. 3, a bubble can also be supplied at the high speed of 5-30 times reciprocation per minute, making it a lateral direction of a substrate advancing direction.

In the case of FIG. 2, the time required for the foamed foam to be coated on the substrate is increased due to the structure of the foam coating machine (15 to 20 minutes), thereby increasing the size of the foam and forming a relatively thick foam, that is, the foamed foam is 15 minutes. In the case of a stagnation, the average diameter of the foam is more than doubled. In the case of using fine bubbles, the required time can be shortened as shown in FIG. 3 to maintain fine bubbles. In addition, when the foaming time is shortened as described above, even when coating the substrate having a strong hydrophilicity or a portion where the foam is in contact with the foam, the foam may be prevented from being absorbed by the substrate and defoaming. In the case of high viscosity viscosity of 10,000 cps, the average diameter of the resin foam is about twice as large as about 15 minutes, and the average diameter of the microbubbles is rapidly supplied by rapidly supplying the resin foam using the rapidly reciprocating foam supply nozzle of FIG. This phenomenon can be prevented from increasing. In addition, under low viscosity conditions of 5.000 cps or less, defoaming can be prevented by shortening the coating time after foaming.

In this step, the degree of penetration can be controlled by adjusting the gap between the knife and the substrate.

The dust collecting filter product produced through this step can control the average diameter of the foam in various ranges, and in particular, when using the apparatus of Figure 3 can produce a product having an average diameter of the foam of 1 ~ 10 ㎛, in particular By improving the drying method described below, a product having an average diameter of foam of 1 to 5 μm can also be produced.

Pile layer forming step

This step is a step of forming a pile layer by flocking short fibers to the coating layer. Before the coating layer formed by the resin foam coating step is dried, the substrate on which the coating layer is formed is introduced into a flocking chamber in which an electric field is formed, and the single fiber is charged using static electricity using the coating layer as an adhesive before the drying, and then the electric field in the flocking chamber is charged. Using to drop onto the coating layer in a standing state to be fixed. The pile layer forming step is preferably as soon as possible after coating.

The flocking process of this step can be carried out by applying a known technique using a conventional apparatus, and as shown in Fig. 4, the flocking apparatus used in the general flocking process has a short fiber supply unit 41 in which short fibers are supplied at the top. ), The short-fiber supply portion 41 is provided with an electric field forming portion 42 to form an electric field, the lower portion is made of a transfer device 43, etc. through which the substrate passes. Also preferably, the drying device 44 may be installed continuously at the outlet end of the transfer device 43.

As the short fiber, short fibers of various materials such as organic, inorganic, or metal materials may be used, and short fibers of various types may be used. In particular, when the filter medium for the filter of the present invention is used in the filter, in order to be made not only with mechanical filtration by short fibers but also with electrostatic filtration using electrostatic force, a material that exhibits dust and electricity in the air may be used. Preferably, polyester (PET), nylon (Nylon), viscose (Viscose), acrylic (Acrylic), polypropylene (PP), PVC, PVC: carbon fibers (Carbon fibers), carbon fibers, glass fibers (Glass) fibers), activated carbon fibers (ACF) or nylon / PET split composite yarn, and the like. In addition, the shape of the short fibers is preferably smaller in diameter than the pores in order to prevent pores of the foam resin coating layer. More preferably, the diameter of the short fibers constituting the pile layer is 0.8 to 3 denier.

In addition, the length of the short fiber may be used as the short fiber of the appropriate length according to the shape of the filter used in the filter medium, in particular, in the case of having a bag shape of the bag filter or when used in a bent shape in the cartridge filter Short fibers of appropriate length may be used in terms of the size of the dust to be desired, the aspect of filtration efficiency, and the fall prevention of short fibers. In particular, the thickness of the short fibers is preferably composed of fibers having a length of 0.3 to 2 mm in order to prevent the fall of the short fibers and filtration efficiency.

One end of the short fibers is fixed in various ways on the porous foam resin coating layer and the other end is free form, so that a plurality of parallel to each other is arranged. This allows the dust to pass through the pile layer consisting of a plurality of short fibers before approaching the foam resin coating layer and allows the pile layer to perform electrostatic filtration as well as mechanical filtration.

Drying step

This step is to dry the flocked substrate. The drying step may also be dried using a conventional technique generally applied, preferably, the drying step is carried out in three steps as follows.

1. Gelation Step

The coating surface is gelled for 30 seconds to 1 minute with a gentle wind of 50-90 ° C. (wind speed of 1 m / sec or less) in order to prevent bubbles from expanding and breaking upon rapid drying of the foam coated substrate.

2. Drying Step

The gelled substrate is dried at a temperature of 100 to 150 ° C. for 1 to 3 minutes. At this time, when the drying temperature is less than 100 ℃, the drying speed is slow, if it exceeds 150 ℃ there is a problem that the crack occurs and the coating film is weak.

3. Heat treatment step

The dry coating film as described above is heat-treated for 20 seconds to 2 minutes at a temperature of 150 ~ 190 ℃.

The substrate dried through the three steps as described above may maintain fine bubbles of 1 to 10 μm.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

[Example]

Example 1

(Emulsion Preparation)

Al of an acrylic resin (MMA) 76 parts by weight, fillers of a water-soluble resin (OH) ₃ 7 parts by weight, and talc (talc) 5 parts by weight, referred to foam agent sodium lauryl sulfate, 1 part by weight of ammonium stearate based 7.5 Foam stabilizer Parts by weight, and 0.5 parts by weight of silicone, 0.5 parts by weight of polycarboxylic acid polybasic salt (50%) as a dispersant, 1.1 parts by weight of melamine-formaldehyde resin (including 0.1% by weight of catalyst) as a crosslinking agent, and 0.9 parts by weight of a silicone binder as a binder. Mix uniformly. Then, 0.5 parts by weight of sodium alginate was added as a thickener to thicken to prepare an emulsion.

(Resin bubble preparation stage)

The emulsion prepared as described above was fed to the bubble generator by the apparatus of FIG. 2 at a rate of 150 kg / h. At this time, the compressed air (8 kg / ㎠) of the bubble generator so that the value of the fluorine (flow meter) to 7500 cc / min, and stirred at a speed of 500 rpm to produce a resin foam.

(Resin foam coating step)

After the resin foam produced through the apparatus of FIG. 2 was introduced into the foam coater as described above, the foam was coated through the supply nozzle having a distance of 5 m from the foamer to the supply nozzle. At this time, the speed of the substrate was 7 m / min, and the time from foaming to coating was 2 minutes and 30 seconds.

(File layer forming step)

The substrate is introduced into a flocking chamber, and PET short fibers having a length of 2 mm and having a thickness of 0.5 denier are fed into an electric field charged at 5 kV / cm to form a pile layer.

(Dry step)

The foam-coated substrate was gelled for 1 minute with 70 ° C mild wind (within 1 m / sec), then dried for 2 minutes with strong wind at 140 ° C, and heat-treated at 180 ° C for 30 seconds to collect the dust filter. Prepared.

Example 2

(Emulsion Preparation)

Al of an acrylic resin (MMA) 76 parts by weight, fillers of a water-soluble resin (OH) ₃ 7 parts by weight, and talc (talc) 5 parts by weight, referred to foam agent sodium lauryl sulfate, 1 part by weight of ammonium stearate based 7.5 Foam stabilizer Parts by weight, and 0.5 parts by weight of silicone, 0.5 parts by weight of polycarboxylic acid polybasic salt (50%) as a dispersant, 1.1 parts by weight of melamine-formaldehyde resin (including 0.1% by weight of catalyst) as a crosslinking agent, and 0.9 parts by weight of a silicone binder as a binder. Mix uniformly. Then, 0.5 parts by weight of sodium alginate was added as a thickener to thicken to prepare an emulsion.

(Resin bubble preparation stage)

The emulsion prepared as described above was fed to the bubble generator by the apparatus of FIG. 3 at a rate of 150 kg / h. At this time, the compressed air (8 kg / ㎠) of the bubble generator so that the value of the fluorine (flow meter) to 7500 cc / min, and stirred at a speed of 500 rpm to produce a resin foam.

(Resin foam coating step)

After the resin foam produced through the apparatus of FIG. 3 is introduced into the foam coater as described above, the reciprocating speed is 6 round trips / minute, and the foam is coated through the supply nozzle having a distance of 5 m from the foamer to the supply nozzle to coat the substrate. It was. At this time, the speed of the substrate was 7 m / min, and the coating was adjusted to a thickness of 0.3 mm by adjusting the height of the coating knife so that the coating thickness on the right and left of the substrate, the time from coating to foaming took 1 minute 30 seconds.

(File layer forming step)

The substrate is introduced into a flocking chamber, and PET short fibers having a length of 2 mm and having a thickness of 0.5 denier are fed into an electric field charged at 5 kV / cm to form a pile layer.

(Dry step)

The foam-coated substrate was gelled for 1 minute with 70 ° C mild wind (within 1 m / sec), then dried for 2 minutes with strong wind at 140 ° C, and heat-treated at 180 ° C for 30 seconds to collect the dust filter. Prepared.

Example 3

In the same manner as in Example 2, except that the foam generator in the resin foam preparation step of Example 2 was set at a speed of 250 rpm, and the reciprocating speed of the supply nozzle in the resin foam coating step was 20 round trips / minute. Was carried out.

Example 4

In the same manner as in Example 2, except that the foam generator in the resin foam preparation step of Example 2 was set at a speed of 50 rpm, and the reciprocating speed of the supply nozzle in the resin foam coating step was 30 round trips / minute. Was carried out.

As a result of photographing the surface of the filter prepared in Examples 1 to 4 with an electron microscope (× 400), the filter of Example 1 according to the present invention includes pores having an average diameter of 25 μm or more as shown in FIG. 5. As shown in FIG. 6, the filters of Examples 2 to 4 contained ultrafine pores having an average diameter of 5 to 10 μm.

As described above, the filter medium for filters of the present invention has a multi-layered filtration structure using a substrate having a different pore size and a foam resin coating layer from fine dust generated in the incinerator, steel, powder industry, cement industry, etc. In addition to efficient filtering, the pressure drop through the filter media can be reduced, effectively removing fine dust without requiring a high differential pressure.

In addition, the pile layer formed on the foam resin coating layer may be combined with the electrostatic filtration as well as mechanical filtration to achieve a more effective filtering effect. In other words, the foam coating (Foam coating only) product has a disadvantage in that the initial efficiency is very weak in the filtration of low concentration fine dust (mainly atmospheric dust) of less than 100 mg / m ³ Floating the microfiber of the present invention In the case of fine dust collision (diffusion, diffusion, mesh) effect and the synergistic effect of the electrostatic effect by friction of the microfiber due to the influence of the flow rate of the air layer, high concentration dust (more than 100 mg / m ³ ) Of course, to provide a filter medium and a method for producing the filter that can efficiently remove even low concentration dust (100 mg / m ³ or less).

In addition, by filtering the fine dust irrespective of the pore size, and by almost filtering the dust off the surface, reducing the pressure loss caused by the use of the filter, it has the effect of easy reuse or cleaning.

In addition, it can be applied to various types of filters such as dust collector filter, pre-filter, pocket filter, cartridge filter, car air cleaner filter, water treatment filter, etc. There is this.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various modifications and changes made by those skilled in the art without departing from the spirit and scope of the present invention described in the claims below. Changes are also included within the scope of the invention.

Claims (11)

A substrate having a porous structure; Porous foam resin coating layer comprising a plurality of pores bonded on the plane of the substrate; And, A filter medium for a filter, characterized in that one end comprises a pile layer composed of a plurality of short fibers fixed on the porous foam resin coating layer. The method of claim 1, The size of the pores included in the porous foam resin coating layer is larger than the thickness of the short fibers, the thickness of the short fibers constituting the pile layer is a filter medium, characterized in that 0.8 to 3 denier. The method of claim 1, The filter medium for a filter, characterized in that the length of the short fibers constituting the pile layer is 0.5 to 2 mm. The method according to any one of claims 1 to 3, A filter medium for a filter, wherein the filter medium is used as a filter medium for a dust collecting filter, a prefilter, a pocket filter, a cartridge filter, a filter for automobile air cleaner, and a filter for water treatment. a) preparing a resin foam to produce foam by stirring the emulsion in a bubble generator; b) a resin foam coating step of coating the produced foam on a substrate; c) forming a pile layer by flocking short fibers to the coating layer; And, d) a drying step of drying the substrate coated with the resin foam and the pile layer formed Method for producing a filter medium for filters comprising a. The method of claim 5, Step a) is to produce a foam having a diameter of 1 ~ 5 ㎛, step b) is characterized in that the foam is coated on the substrate while maintaining the average diameter of the foam 1 ~ 10 ㎛ The manufacturing method of the filter medium for filters. The method of claim 5, The step c) is the manufacturing method of the filter medium for filters, characterized in that the flocculation process of short fibers having a thickness of 0.5 to 3 denier. The method of claim 5, The step c) is a method for producing a filter medium for a filter, characterized in that the flocking of short fibers of 0.3 to 2 mm in length. The method of claim 5, The drying of step d) is performed by gelling at a temperature of 50 to 90 ° C., drying to a temperature of 100 to 150 ° C., and heat treatment to a temperature of 150 to 190 ° C. Manufacturing method. The method of claim 6, Production of the foam of step a) comprises a stator forming an outer wall; A rotor erected at the center of the stator; A rotor side pin which is vertically fixed to the rotor and has a pin thickness of 4 to 5 mm; A stator side pin that is not intersected with the rotor side pin and is fixed to the stator in parallel and has a thickness of 4 to 5 mm; And a three-dimensional ultra-fine pores having an average diameter of 5 to 10 μm, wherein the bubble generator is installed at an upper end of the stator and is made of a bubble generator made of a supply pipe for introducing an emulsion liquid, air pressure, and a crosslinking agent into the stator. Method for producing filter medium. The method of claim 6, The coating of step b) is a bubble supply nozzle for supplying the resin foam generated in the bubble generator to the substrate; A roller for conveying the substrate; And three-dimensional ultra-fine pores having an average diameter of 5 to 10 μm, which are positioned in the vertical direction on the substrate and made of a foam coating machine made of a coating knife having a rounded contact with the substrate. A method for producing a filter medium for filters.

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