KR102281271B1 - Air Filter with low pressure drop - Google Patents

Abstract

The present invention is a filter medium installed in a semiconductor factory, a display device manufacturing factory, or a clean room to remove contaminants that may be generated in a semiconductor or LCD manufacturing process or may be introduced from the outside, and a fibrous first filter media layer and a first filter media layer are synthesized It relates to a low differential pressure filter media in which a second media layer having an average diameter smaller than that of the fibers is incorporated.
In addition, in the present invention, in the filter media including the first filter media layer and the second media layer, the average diameter of the synthetic fibers included in the first media layer is greater than the average diameter of the synthetic fibers included in the second media layer. It relates to a low differential pressure filter medium for a semiconductor clean room in which a non-woven filter medium layer is additionally incorporated between the fibrous first filter medium layer and the second filter medium layer, and has a multi-layered structure that extends the replacement cycle of the filter medium through the improvement of the collection amount It is about the differential pressure media.

Description

Low differential pressure media {Air Filter with low pressure drop}

The present invention is a filter medium installed in a semiconductor factory, a display device manufacturing factory, or a clean room to remove contaminants that may be generated in a semiconductor or LCD manufacturing process or may be introduced from the outside, a fluororesin membrane filter and/or a first media layer, It relates to a filter media in which a second media layer having an average diameter smaller than that of the fibers of the first media layer is incorporated into one.
In addition, in the present invention, in the filter media including the first filter media layer and the second media layer, the average diameter of the synthetic fibers included in the first media layer is greater than the average diameter of the synthetic fibers included in the second media layer. It relates to a mediator, characterized by dots.

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More specifically, the present invention relates to a filter medium for a semiconductor clean room in which a fluororesin membrane filter and/or a filter medium layer for collecting filtrates is further incorporated between the fibrous first and second filter media layers, and the amount of filtrates collected is improved It relates to a filter medium with a multi-layered structure that extends the replacement cycle of the filter medium through

The frequency of human inhalation or exposure to polluted air is very high according to the advanced industrial environment. In addition to health reasons, safety management is being emphasized to reduce the defective rate of products due to air pollution in industrial sites. the current situation.

Therefore, a high clean air environment is needed to reduce the defect rate of products in industrial sites, and a clean room is installed by investing a huge amount of money, and high functional filter media is installed in the clean room in various ways.

The airflow method in a clean room is generally divided into three types: vertical laminar flow, horizontal laminar flow, and non-laminar flow. In the vertical laminar flow method, more than 80% of the ceiling surface is equipped with high-functional filter media, and airflow is blown down. This method is suitable for facilities requiring cleanliness class 10 to 1,000 because the ceiling air circulated to the floor and circulated to the ceiling is ventilated in the shortest distance.

The horizontal laminar flow method is a method suitable for facilities requiring cleanliness class 100 to 10,000, in which a high-functional filter is installed on one side of the wall to form a laminar flow, and then ventilated to the opposite wall to purify.

In the non-laminar flow method, a high-functional filter is installed on a part of the ceiling and the air blown out is circulated through the wall as far as possible. It is possible to install a filter unit at the outlet of the air conditioning duct, so cleanliness class 100 to 100,000 This is a suitable method for the required facility.

Clean rooms installed in various ways as described above have strict class standards in the field, so they block residual dust in the air supplied from the outside to 0.3㎛ or less to maintain cleanliness, lower the defect rate of products, and maintain positive pressure. Due to the nature of the clean room, which blocks the inflow of air from the air, a large amount of air is required.

In the case of glass fibers used in the production of filter media so far, since they have a high initial static pressure and are composed of short fibers, they may absorb moisture and be damaged by wind pressure. In addition, the chemical resistance is weak, so it cannot be used in an environment where strong acids such as hydrofluoric acid are used, and the defect rate is high due to the weak tensile strength, and there are disadvantages in that it is easy to break and cannot be incinerated.

However, in the case of a melt blown microfiber filter (Melt Blown fibrous filter, MB filter) manufactured by a melt spraying method that can be used as an alternative material for glass fiber, the initial static pressure is also high, so there is a difficulty in lowering the efficiency to maintain the air volume. As a result, there is a problem in that the maintenance cost and the management cost are greatly increased.

Melt blown (MB) filter, which is currently widely used, is a three-dimensional fiber structure filter manufactured by melt spinning polypropylene resin or polyethylene or polyester resin into microfiber as long as it is harmless to the human body and has excellent heat resistance. Due to its excellent strength, the amount of impurity captured increases, thereby increasing the efficiency of use of the filter media.

Polypropylene or polyester is a material that is mechanically and chemically very stable, so secondary contamination by filter decomposition substances does not occur. In addition, since the thickness and length of the fibers forming the melt blown filter can be uniformly adjusted, the filtration precision can be increased, and there is an advantage that the filtration precision can be maintained despite changes in wind pressure.

The HEPA (High Efficiency Particulate Arrestor) filter is a high-performance filter that removes fine particles from the air, and was developed by the U.S. Atomic Energy Commission to remove radioactive materials. The HEPA filter is responsible for adsorbing particles larger than or equal to 0.3 μm (micrometer), and it is divided into H10 to H14 stages.

Among these grades, H12 grade should be able to filter 99.5% and H13 grade (medical use) 99.95% to collect impurities. The highest H14 grade should be able to adsorb and remove 99.995% of it.

Through the high-performance H12 filter and the sealed filtration system of 4 or more stages, it is possible to adsorb more than 99.95% of harmful particles of 0.05μm smaller than 0.3μm that the HEPA filter can remove. From fine dust, bacteria, and house dust mites that cause allergies and asthma to some viruses with a size of 100 nanometers or less, it can be filtered if it is in the form of droplets or agglomeration.

However, since the HEPA filter is difficult to clean due to its characteristics, the filtrate is accumulated in the HEPA filter, so that when the filter is used for a long period of time, product performance is deteriorated due to an increase in filtration pressure. Therefore, there is an urgent need to develop a new technology to extend the replacement cycle of the HEPA filter by increasing the filtrate collection capacity of the HEPA filter to extend the lifespan.

Meltblown nonwoven fabric spun polymers capable of forming thermoplastic fibers through hundreds of small spinnerets, and the polymer extruded from the spinneret in a molten state is superfine by hot air sprayed from both sides of the spinneret at high speed. It is a self-bonding nonwoven fabric in which microfibers are randomly stacked on a collector.

This melt blown nonwoven fabric exhibits performance corresponding to the MERV 7 to 16 level of the American air filter standard ANSI/ASHRAE 522 (1999), and the higher the MERV value, the better the filter efficiency and the higher grade filter.

Meltblown nonwoven fabric has low shape stability after bending due to its flexible nature, so it cannot maintain the bending shape after bending and returns to its original shape. Occurs. Therefore, the filter's ability to maintain shape is essential, especially in a cabin filter for automobiles or a high-efficiency medium filter in which a large amount of air flow is introduced into a small filter area.

The melt blown (MB) filter used as the main material of such a HEPA filter performs filtering to block harmful dust and dust while airflow passes through three-dimensional pores in the range of 1 to 10 microns. A phenomenon in which the filter media (midia) in the flow in part is clogged occurs, which causes a problem in that the differential pressure rises on the filter surface.

It is mainly melt blown nonwoven fabric used as the filter material of the present invention. Melt-blown non-woven fabric is a non-woven fabric that is disorderly collected by spinning a molten resin into microfibers having a diameter of about 1 micrometer using compressed air. It is also produced by mobilizing complex spinning, split spinning, and electrospinning methods.

Meltblown media produced by single-component spinning by DuPont or Hyosung in Korea is manufactured from microfibers of 0.3 denier to 0.2 denier. A melt blown filter medium made of 0.0001 denier grade ultra-microfibers manufactured by Toray Corporation of Japan by a multi-component spinning method may be used as the filter layer of the present invention. These melt blown nanofiber nonwoven fabrics are fabricated with a filter media that exhibits membrane-level selective permeability.

In the present invention, the fiber diameter of the melt blown media forming the two layers of media is different from each other to maintain the filtration ability of HEPA 13 or higher, and the spunbond media layers are combined between the media layers to collect the filtrate while capturing the entire filter media. The mechanical strength was reinforced to prevent the physical distortion of the filter media even under considerable wind pressure.

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Korean Patent No. 10-0731791 discloses a method for manufacturing a filter using a composite spinning melt blown nonwoven fabric and a filter formed therefrom. This prior art filter manufacturing method is (S1) a two-component composite spun meltblown nonwoven fabric comprising two-component composite spun fibers of a first thermoplastic polymer having a predetermined melting point and a second thermoplastic polymer having a lower melting point than the first thermoplastic polymer. preparing; (S2) laminating the two-component composite spun meltblown nonwoven fabric on one or both surfaces of the one-component meltblown nonwoven fabric made of a third thermoplastic polymer having a higher melting point than that of the second thermoplastic polymer; and (S3) heat bonding the two-component composite spun meltblown nonwoven fabric and the one-component meltblown nonwoven fabric to each other by applying heat to the laminated nonwoven fabric at a temperature capable of melting only the second thermoplastic polymer. In International Patent No. PCT/US2000/02458, filed by US 3M, the present invention provides a novel fluorochemical oligomer and a polymer composition comprising a fluorochemical oligomer compound and a thermoplastic or thermosetting polymer. The polymer composition is useful for making molded articles such as fibers and films having desirable oil and water repellency properties. On the other hand, the Donaldson Company of the United States of America, through International Patent Application No. PCT/US2005/039971, a thermally bonded sheet combining high strength and excellent filtration properties, a filter medium or a filter comprising a shaped or formed medium includes Composite filters are disclosed in which a significant proportion of organic or inorganic glass fibers, bicomponent thermoplastic binder fibers, and optionally resin binders, secondary fibers or other filtration materials are combined in the formed layer. The use of bicomponent fibers significantly reduces or prevents film formation from the binder resin and also reduces the lack of uniformity within the medium or element due to migration of the resin to a specific location in the media layer, without a separate resin binder or at a minimum. It makes it possible to form a media layer or filter element with a positive ledge binder. The use of bicomponent fibers allows for reduced compression, improves solidity, increases tensile strength, and reduces the use of media fibers such as glass fibers and other fine fiber materials added to media layers or filter elements. improve Bicomponent fibers also provide improved processability during downstream processes such as furnish formation, sheet or layer formation and thickness adjustment, drying, cutting, and filter element formation. These two components combine in various proportions to form a high strength material with significant filtration capacity, permeability and filtration life. EMD Millipore Corporation of the United States through Republic of Korea Patent Application Publication No. 10-2019-0011838 on February 7, 2019 disclosed a rough porous polymer nonwoven inner layer positioned between the first and second polymer fiber-containing filter mats. A fluid filtration device comprising a composite filter medium having The diameters of the fibers in the first and second filter mats are different, each filter mat has a different pore size rating, and the first and second polymer fibers in the filter mats can be electrospun nanofibers. wherein the inner layer has a coarser pore size as compared to the first or second filter mat, and thus the composite media has increased dust compared to filter layers laminated directly on top of each other without the presence of a coarse inner layer therebetween. It has revealed a technology that shows its capture ability. On the other hand, Japan's Asahi Kasei Sengi Co., Ltd., through the international patent application PCT/JP2007/051091, as a laminated nonwoven fabric integrated by thermocompression bonding, (a) layer: having one or more long fiber nonwoven layers made of a thermoplastic resin ; (b) layer: having at least one ultrafine fiber nonwoven fabric layer made of a thermoplastic resin of the same series as layer (a); (c) layer: having at least one composite long fiber nonwoven fabric layer made of a thermoplastic resin; (1) ) the melting point difference between the fibers constituting the nonwoven fabric of the layer (a) and the fibers constituting the nonwoven fabric of the layer (b) is 30° C. or less; (2) The long composite fiber made of a thermoplastic resin constituting the nonwoven fabric of layer (c) contains a low-melting component, and the melting point of the low-melting component is 40 to greater than the melting point of the fibers constituting the nonwoven fabric of layer (a). A heat-adhesive laminated nonwoven fabric characterized in that it is low at 150°C has been disclosed.

Therefore, the present invention is to solve the problems of the prior art as described above, the collection capacity is expanded, the replacement cycle of the filter medium is longer, is resistant to moisture, and the service life is prolonged while maintaining the gas filtration efficiency of the existing HEPA filter. An object of the present invention is to provide high-performance media.

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In addition, the present invention provides a composite of a first filter media layer and a first filter media layer having different diameters of fibers of the melt blown media forming the filter media, and a spun-bonded media layer is disposed between the first and second media layers. An object of the present invention is to provide a high-performance filter media that can extend the replacement cycle of expensive media by increasing the filter material collection capacity.

The low differential pressure filter material according to the present invention includes a first filter media layer and a second filter media layer each including synthetic fibers, wherein the average diameter of the synthetic fibers included in the first filter media layer is included in the second filter media layer. It is larger than the average diameter of the fibers, and when the treatment capacity is 32 L/min, the differential pressure is less than 5.5 mmaq, and the filtration efficiency can be greater than 99.98%.

The synthetic fiber included in any one of the first and second filter media layers may be manufactured by a melt blowing method. A spun-bonded nonwoven fabric media layer may be further included between the first media layer and the second media layer.

The average fiber diameter of the melt blown fibers included in the first filter media layer may be 1.0㎛ to 10㎛. The average fiber diameter of the melt blown fibers included in the second filter media layer may be 0.1 μm to 1.0 μm.

Any one of the fibers of the first and second media layers may be made of one or more materials selected from the group consisting of polyolefin, polyester, polyamide, and polyphenylene sulfide. Preferably, the synthetic fibers may be prepared from polypropylene and polyethylene terephthalate, respectively.

In addition, the first filter media layer and the second media layer, or the first media layer, the non-woven fabric media layer, and the second media layer may be bonded to each other by an ultrasonic lamination method.

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The low differential pressure filter material according to the present invention can save energy due to low pressure loss, is easy to construct because there is no fear of damage to the filter material, and is strong against moisture, which is advantageous for humidification and cooling. In addition, it has the advantage of low noise, easy installation and disposal, and the ability to maintain the air volume in a narrow space while maintaining the existing HEPA efficiency (H13, 99.97%).

1 is an internal air circulation diagram of a clean room in which a filter medium according to the present invention is installed.
2 is a view schematically showing a filter medium according to the present invention.
3 and 4 are test results of the filter media according to the present invention.
5 and 6 are pictures of the final product of the filter material according to the present invention.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs.

In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly specifically defined.

Hereinafter, the filter medium according to the present invention will be described in more detail.

In one embodiment of the present invention, as shown in FIG. 2 , the filter media according to the present invention includes a first filter media layer and a second media layer each including synthetic fibers, and the average fiber diameter of the first media layer This may be different from the average fiber diameter of the second filter media layer.

The first and second filter media layers of the filter media according to the present invention each include synthetic fibers having different average fiber diameters, thereby reducing pressure loss and increasing dust collection efficiency. In addition, due to the structure including synthetic fibers having different average fiber diameters, when the high-functional filter media is used in a filter device using a corona charging method, it is possible to prevent the filter media from being shortened.

When the fiber diameters of the filter media layers are similar, when the energy of the corona charging method flows for a predetermined time, the differential pressure rises rapidly, and the efficiency decreases. In the present invention, by differentiating the average fiber diameters of the first and second filter media layers, it is possible to collect particles having different diameters by varying the pore sizes between the fibers of the first and second media layers. It has the advantage of extending the lifespan.

The filter media according to the present invention may have a differential pressure of less than 5.5 mmaq and a filtration efficiency of 99.98% or more when the treatment capacity is 32 L/min.

The differential pressure of the commonly used filter media is in the range of 25 to 30 mmaq at a processing capacity of 32 ℓ/min. Therefore, if the processing capacity is further increased, the differential pressure becomes too large, which makes it difficult to use, and may cause serious problems such as abruptly shortening or breaking the life of the filter media.

However, the differential pressure of the filter media according to the present invention is only 5.5mmaq at a processing capacity of 32ℓ/min, and even if the processing capacity is increased to 56ℓ/min, the differential pressure is 14.8mmaq, which is significantly lower than the differential pressure of the existing filter media, so power consumption is reduced It has the advantage of being able to easily maintain the cleanliness inside the clean room because it is small and the air circulation is smooth.

In one embodiment of the filter media according to the present invention, the synthetic fibers included in at least one of the first filter media layer and the second filter media layer may be formed by a melt-blown method. In the melt blowing method, ultra-fine fibers with a fiber diameter of 0.3-5 μm can be manufactured by laminating micro-fine fibers that are micro-fine fibers by hot air sprayed at high speed from a spinnerette formed of hundreds of small orifices. It has excellent flexibility, impermeability, insulation, and barrier properties, and has the advantage of excellent filtration performance when electrostatic performance is given.

In addition, since the range of materials that can be selected is wide, it is easy to implement desired physical properties such as incineration capacity, resolution, tensile strength, formability, and water repellency.

In one embodiment of the filter media according to the present invention, as shown in FIG. 2 , a nonwoven fabric media layer may be further included between the first media layer and the second media layer. By further including a non-woven filter media layer between the filter media layers, it may have the effect of enhancing the collecting capacity and improving the moldability and durability. In addition, the nonwoven fabric filter media layer may be a conventional positive charge coating-treated nonwoven fabric and/or polypropylene nonwoven fabric having an average pore size of 1 μm to 2 μm, preferably an average pore size of 1 μm to 1.8 μm.

At this time, if the average pore size is less than 1㎛, the filtration amount may decrease and it may not be possible to secure a sufficient cumulative filtration amount. If the average pore size exceeds 2㎛, the filtration amount may increase but the filtration performance may be deteriorated. And, the polypropylene melt blown nonwoven fabric of the present invention may have an average thickness of 100 μm to 250 μm, preferably an average thickness of 120 μm to 220 μm, and more preferably 150 μm to 175 μm.

If the average thickness of the polypropylene melt blown-calendaring nonwoven fabric is less than 100 μm, the filtration performance may decrease, and if the average thickness exceeds 250 μm, the filtration amount is reduced, there is no further improvement in filtration performance, and the cumulative filtration amount is rather reduced. Therefore, there may be a problem that the use cycle is shortened.

The positive charge coating-treated nonwoven fabric may include a modified nonwoven fabric; and a positive charge coating layer on the inside and the surface of the nonwoven fabric, wherein the positive charge coating-treated nonwoven fabric may have a surface charge of 10 mV to 40 mV, preferably 20 mV to 40 mV.

The modified nonwoven fabric of the positive charge coating-treated nonwoven fabric is a modified nonwoven fabric inside and/or on the surface, and the nonwoven fabric is applicable as long as it is commonly used, and preferably a chemical bonding nonwoven fabric (Chemical Bonding), a thermal bonding nonwoven fabric ( Thermal Bonding), Air Ray, Wet Ray, Needle Punching, Spanless (Water zet), Spun Bond, Melt Blown ), stitch bond (Stitch Bond) and electro spinning (electro spinning) may be in any one form selected from nonwoven fabric.

In addition, the fibers constituting the nonwoven fabric include at least one selected from polypropylene fibers, polyethylene terephthalate fibers, polyethylene fibers, polyester fibers, nylon fibers and cellulose fibers, preferably polypropylene fibers, polyethylene terephthalate fibers, polyethylene It may include one or two or more types selected from fibers and polyester fibers, and more preferably one or two types selected from polypropylene fibers and polyethylene terephthalate fibers.

In addition, the modified nonwoven fabric has an average thickness of 0.1 mm to 2 mm, preferably 0.2 mm to 1 mm, and at this time, the average thickness 0.1 If the average thickness is less than 0.1 mm, the removal efficiency is reduced because the adsorption path is short. There is a reduced problem, and if it exceeds 2 mm, there may be a problem in that the filtration amount is reduced due to the generation of a differential pressure during filtration.

In addition, the average fiber diameter of the fibers constituting the modified nonwoven fabric may be 0.5 μm to 10 μm and an average pore of 1 μm to 30 μm, preferably an average fiber diameter of 0.5 μm to 8 μm and an average pore of 1 μm to 10 ㎛ may be, and more preferably, the average fiber diameter may be 0.5㎛ ~ 5㎛, and the average pores 1㎛ ~ 8㎛.

At this time, if the average fiber diameter of the fibers constituting the nonwoven fabric is less than 0.5 μm, there may be a problem in that the filtration amount decreases due to the generation of differential pressure during filtration, and if it exceeds 10 μm, there may be a problem in that the porosity decreases and the filtration performance decreases can In addition, if the average pore size is less than 1 μm, the flow rate may decrease, and if it exceeds 30 μm, there may be a problem in that the filtration performance is reduced.

In addition, the positive charge coating layer constituting the positive charge coating-treated nonwoven fabric includes a polyfunctional amine compound, and the polyfunctional amine compound serves to impart an electrostatic property showing a positive charge to the inside and outside of the modified nonwoven fabric, and polyethylene One or two or more selected from imine, diethylenetriamine, piperazine, dimethylenepiperazine and diphenylamine may be mixed and used, preferably one or two selected from diethylenetriamine and diphenylamine More than one species can be mixed and used.

In addition, the positive charge coating layer is preferably formed with an average thickness of 0.01 μm to 3 μm, preferably 0.05 μm to 1 μm, in this case, the average thickness of the positive charge coating layer is 0.05 μm The problem of physical property deviation due to a decrease in the uniformity of the coating layer There may be, and if the average thickness exceeds 3 μm, the durability of the coating layer may deteriorate and the coating may peel off, and since there is no further increase in filtration performance, it is better to form a positively charged coating layer to have an average thickness within the above range.

The filter media according to the present invention may have a shape that is bent multiple times so that the cross-section of the filter media has mountains and valleys, but the shape of the filter media can be flexibly determined by a person skilled in the art to which the present invention belongs .

In addition, in one embodiment of the filter media according to the present invention, the first average fiber diameter, which is the average fiber diameter of the synthetic fibers included in the first filter media layer, may be 1.0 μm to 10 μm, and is included in the second filter media layer. The second average fiber diameter, which is the average fiber diameter of the synthetic fibers to be used, may be 0.1 μm to 1.0 μm.

When the first average fiber diameter is less than 1.0 μm, there is a risk that the pressure loss may increase, and if it is greater than 10 μm, the efficiency and/or moldability of the filter medium may be deteriorated. The second average fiber diameter is most preferably in the range of 0.1 μm to 1.0 μm in terms of pressure loss and filtering efficiency, and is preferably not the same as the first average fiber diameter even within the above range.

For example, it is not preferable that both the first average fiber diameter and the second average fiber diameter are 1.0 μm. If the average fiber diameter of the two filter media is similar, the differential pressure may be lowered, but foreign substances of various particle diameters cannot be removed, and thus a problem in filtration performance may occur. In addition, when the energy of the corona charging method passes for a certain period of time, the differential pressure increases and the efficiency decreases.

In one embodiment of the filter media according to the present invention, the synthetic fibers constituting each of the filter media layers include polyolefins including polyethylene, polypropylene, polybutylene, polyisobutylene, and the like; Polyglycolide, polylactic acid, polycaprolactone, polyhydroxyalkanoate, polyhydroxybutylate, polyethylene adipate, polybutylene succinate, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate , polyester including polyethylene naphthalate and the like; polyamides, including aliphatic polyamides (eg, nylon), polyphthalamides, aramids, and the like; And it may include one or more selected from the group consisting of polyphenylene sulfide, such as linear, cross-linked, but is not limited thereto.

Preferably, the synthetic fiber may include polypropylene and polyethylene terephthalate. Synthetic fibers formed by melt blowing have the advantage of low pressure loss and high efficiency. In particular, synthetic fibers made from polypropylene and polyethylene terephthalate have intrinsic electrostatic force to improve charging and filtration efficiency, and can improve the life of the filter media when used in a filter media device using a corona method.

In an embodiment of the present invention, the first filter media layer and the second media layer, or the first media layer, the non-woven fabric media layer, and the second media layer may be bonded to each other by an ultrasonic lamination method.

By using the ultrasonic lamination method, the bond between the filter media layers and/or between the filter media layers and the nonwoven fabric is stronger and the undesirable effect on the filter media performance is minimized, and additional pressure loss due to the use of foreign substances such as adhesives is reduced. can be prevented In addition, it can be expected to increase the life of the material and reduce energy.

Hereinafter, the low differential pressure high functional filter material according to the present invention will be described in more detail through Examples and Comparative Examples, but the present invention is not limited to the following Examples.

All of the following Examples and Comparative Examples were tested under the same conditions (thickness 0.3 mm, 610*610*292T, 60Pleate, etc.).

Example 1

Polypropylene and polyethylene terephthalate synthetic fiber layer (first filter media layer) and non-woven fabric media layer prepared to have an average fiber diameter of 5 μm by melt blowing method, and polypropylene manufactured to have an average fiber diameter of 0.5 μm by melt blowing method And a polyethylene terephthalate synthetic fiber layer (second filter media layer) was ultrasonically laminated to prepare a 610 * 610 * 292T high-functional filter media ( FIGS. 3 and 4 ), and by measuring the performance, Table 1 and Figures 5 to 6 shown in

Comparative Example 1

A high-functional filter medium of 610 * 610 * 292T standard was prepared using glass fibers, and performance was measured and shown in Table 1 below.

Comparative Example 2

A high-functionality filter media of 610 * 610 * 292T standard was prepared using general polypropylene synthetic fibers, and the performance was measured and shown in Table 1 below.

Comparative Example 3

Except that in Example 1, the average diameter of the synthetic fibers of the first filter media layer and the average diameter of the synthetic fibers of the second filter media layer were identically 5 μm, 610 * 610 * 292T specifications were used in the same manner as in Example 1 A high-functionality filter medium was prepared, and performance was measured and shown in Table 1 below.

HEPA FILTER 610*610*292T (60Pleate) Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Filtration Efficiency 99.97% 99.97% 99.91% 99.98% foreclosure 25.4 mmaq 27.0 mmaq 5.0 mmaq 5.1 mmaq processing capacity 32ℓ/min 32ℓ/min 32ℓ/min 32ℓ/min

As shown in Table 1, it can be confirmed that the filter media of Example 1 has less pressure loss and lower initial static pressure than the filter media of Comparative Examples, so that it meets the conditions required for a low differential pressure and high-functionality filter media. In other words, the filtration efficiency exceeds 99.97% (H13 grade, True HEPA efficiency), and the differential pressure is very low, about 5mmaq, so it can filter out foreign substances with high efficiency even though the amount of power consumed in the cleanroom is low. Even if the throughput is increased, it effectively prevents the entry of foreign substances and does not cause the problem of media breakage due to large differential pressure or shortening of the filter media lifespan due to clogging. In fact, even when the processing capacity of the filter medium of Example 1 was increased to 56 l/min, the differential pressure was about 14.8 mmaq, which was significantly lower than the differential pressure of the conventional filter medium.

Specifically, in the case of Comparative Example 1, which is a filter material prepared using conventional glass fibers, the filtration efficiency using glass fibers satisfies 99.97%, but the differential pressure is high at 25.4 mmaq. This is also the same for Comparative Example 2, which is a filter medium manufactured using conventional melt blown fibers, but the high differential pressure can be expected to have a very high possibility of shortening the life of the filter medium due to breakage or clogging.

Comparative Example 3 is a filter material prepared by laminating melt-blown fibers in two layers as in the example of the present invention, and is the same as that of Example 1 of the present invention, except that the fiber diameters of the two layers are the same. The filter media of Comparative Example 3 used a media having the same fiber diameter in both layers and having a fiber diameter larger than that of the first filter media layer of the present invention, so that the differential pressure was lower than that of the embodiment of the present invention, but the filtration efficiency was 99.91%, It can be seen that the efficiency is not satisfied.

Claims (10)

a first filter media layer that is a melt blown HEPA filter layer; and
A low differential pressure filter material comprising a second filter medium layer that is a melt blown HEPA filter layer,
The average fiber diameter of the synthetic fibers included in the first filter media layer is
Larger than the average fiber diameter of the synthetic fibers included in the second filter media layer,
Further comprising a nonwoven filter layer between the first filter media layer and the second filter media layer,
The first average fiber diameter, which is the average fiber diameter of the synthetic fibers included in the first filter media layer, is 1.0 μm to 5 μm, and the second average fiber diameter, which is the average fiber diameter of the synthetic fibers included in the second filter media layer, is 0.1 μm. to 1.0 μm,
When the processing capacity is 32ℓ/min, the differential pressure is less than 5.5mmaq, the filtration efficiency is 99.98% or more,
The first filter media layer, the non-woven filter layer, and the second filter media layer are low differential pressure filter media, characterized in that bonded by an ultrasonic lamination method. The method of claim 1, wherein the synthetic fibers included in the first and second filter media layers are made of one or more materials selected from the group consisting of polyolefin, polyester, polyamide, and polyphenylene sulfide. low differential pressure media. The low differential pressure filter media according to claim 1, wherein the synthetic fibers included in the first and second filter media layers are each made from polypropylene and polyethylene terephthalate. [Claim 2] The low differential pressure filter of claim 1, further comprising a fluororesin membrane filter. delete delete delete delete delete delete

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