KR102390788B1 - Filter media, method for manufacturing thereof and Filter unit comprising the same - Google Patents

Abstract

A filter medium is provided. The filter media according to an embodiment of the present invention has a three-dimensional network structure formed by a porous first support and nanofibers disposed on one surface of the first support, and a coating layer including a functional material surrounds the outer surface of the nanofiber. It is implemented including a fibrous web. According to this, various functions can be implemented complexly in a single filter media by using high molecular compounds with different functions as fiber-forming components or functional additives, and the thickness and pore size of the nanofibers constituting the nanofiber web are uniform and , it is possible to significantly reduce the yarn breakage rate of the nanofibers. In addition, the shape, structural deformation, and damage of the filter medium during water treatment operation are minimized, and the flow path is smoothly secured to have a high flow rate. In addition, it has an extended use cycle due to the excellent durability of the filter media even at high pressure applied during backwashing, and at the same time has improved hydrophilic properties and excellent water permeability, so it can be applied in various water treatment fields.

Description

Filter media, method for manufacturing thereof, and filter unit including same

The present invention relates to a filter media, and more particularly, to a filter media capable of simultaneously expressing advantageous heterogeneous functions, a manufacturing method thereof, and a filter unit including the same.

Separation membranes can be classified into microfiltration membranes (MF), ultrafiltration membranes (UF), nano membranes (NF), or reverse osmosis membranes (RO) according to pore sizes.

Although the separation membranes exemplified above have differences in use and pore size, they have in common that they are either a filter medium formed from fibers or a porous polymer filter medium, or have the form of a complex membrane.

The porous polymer filter media is formed through a method such as sintering the pore-forming agent through a separate pore-forming agent contained in the crude solution or dissolving the pores formed inside the polymer membrane or the polymer hollow fiber in an external coagulating solution. it is common In contrast, the filter medium formed from the fibers is generally manufactured by accumulating the manufactured short fibers and then applying heat/pressure or the like or by applying heat/pressure at the same time as spinning.

A representative example of the filter media formed from the fibers is a nonwoven fabric, and in general, the pores of the nonwoven fabric are controlled by the diameter of the short fibers, the basis weight of the media, and the like. However, since the diameter of the short fibers included in the general nonwoven fabric is in the micro unit, there was a limit to realizing a separator having a fine and uniform pore structure only by adjusting the diameter and basis weight of the fiber. Only a separation membrane comparable to a filtration membrane could be implemented, and it was difficult to implement a separation membrane such as an ultrafiltration membrane or a nano-membrane for filtering finer particles.

A method devised to solve this problem is a separation membrane manufactured through microfibers with a diameter of nanoscale fibers. However, it is difficult to manufacture microfine fibers with a nano-unit diameter with only one spinning process with a fiber spinning process such as general wet spinning. There are problems of inconvenience, cost increase, and extension of production time. Accordingly, in recent years, there is a trend to manufacture a lot of filter media formed from fibers by directly spinning fibers having a diameter of nano units through electrospinning.

Some of the various foreign substances contained in the water to be treated remain in the pores of the filtration medium that has been repeatedly subjected to the water treatment process as described above, or an adhesion layer may be formed on the surface of the filtration medium. there is a problem. In order to solve this problem, a method of preventing the occurrence of the above fouling phenomenon itself through pretreatment or a method of washing the filter medium in which the fouling phenomenon has already occurred can be considered. It is common to remove foreign substances remaining in the filtration medium by applying a high pressure to the filtration medium so as to be in the opposite direction to the inflow, filtration and outflow path. However, high pressure applied during washing of the filter medium may cause damage to the filter medium, and in the case of a filter medium having a multi-layered structure, a problem of separation between layers may occur.

On the other hand, as described above, when fibers are used as a filtration medium, a multifunctional filtration medium including various high molecular compounds as a fiber-forming component or a functional additive can be implemented. At this time, the polymer compound is formed by polymerization of a monomer as a subunit to form a polymer compound as a large unit, and the polymer compound exhibits unique properties different from those of the monomer. That is, a polymer compound having a desired function can be used as a fiber-forming component or an additive by polymerizing a monomer, which is a simple organic material.

Functions of the polymer compound include not only the functional properties expressed by the properties of the polymer compound itself, such as hydrophilic/hydrophobic properties, polar/non-polarity, heat resistance and chemical resistance, but also mechanical strength, ion exchange properties, immobilized catalytic enzyme properties, separability, and minute It also includes functions expressed through interaction with external factors such as acidity and selective permeability.

Accordingly, attempts are being made to improve the efficiency of filter media by realizing multifunctional filtration media having various functions in a complex manner by using high molecular compounds with different functions as fiber-forming components, but in general, they have different functions. Because the high molecular compounds present in the high molecular weight compounds are not uniformly mixed with each other due to lack of compatibility, and even if mixed, their inherent functionality may be lost due to chemical/physical reactions between each other. There is a problem that is difficult to do. Furthermore, because a part of a high molecular compound is mixed with another type of high molecular compound during the mixing process of the high molecular compound, advantageous heterogeneous functionality is not expressed, and undesired secondary adverse effects or reactions may be caused, There is a concern that the reliability and predictability of the implemented filter media may be significantly lowered through this.

Accordingly, it is urgent to develop a filter medium that realizes multifunctional filtration media by using polymer compounds with different functionalities in combination, and minimizes the shape, structural deformation, and damage of the filter media even in the backwashing process performed at high pressure. the current situation.

Registered Patent Publication No. 10-0871440

The present invention has been devised in consideration of the above points, and an object of the present invention is to provide a filter medium having at least two or more functions and a method for manufacturing the same.

In addition, the present invention aims to provide a filter medium having a large flow rate and a fast processing speed as the mechanical strength is improved, thereby minimizing the shape, structural deformation, and damage of the filter medium during water treatment operation, and at the same time ensuring a smooth flow path and a method for manufacturing the same. There is this.

Another object of the present invention is to provide a filter medium having excellent durability that can secure a flow path even at high pressure applied in the backwashing process and minimize interlayer separation and membrane damage, and a method for manufacturing the same.

In addition, another object of the present invention is to provide a plate-type filter unit and filter module that can be variously applied in the water treatment field through a filter medium having excellent water permeability and durability.

In order to solve the above problems, the present invention provides a porous first support and a nanofiber web of a three-dimensional network structure disposed on one surface of the first support, and a coating layer comprising a functional material is formed by nanofibers surrounding the outer surface. It provides a filter medium comprising a.

In addition, according to an embodiment of the present invention, the nanofiber may include a first fiber-forming polymer compound, and the functional material may include any one or more polymer compounds of a second fiber-forming polymer compound and a functional polymer compound.

In addition, the nanofiber web is divided into first to third areas in the thickness direction from the surface in contact with the first support, and the first to third areas have all of the values of Equations 1 to 3 below 0.98 ~1.02 can be satisfied.

[Equation 1]

[Equation 2]

[Equation 3]

In addition, the nanofiber web includes a plurality of pores formed by the intersection of nanofibers, and the values of Equations 4 to 6 below in the first region to the third region may all satisfy 0.98 to 1.02.

[Equation 4]

[Equation 5]

[Equation 6]

In addition, the first fiber-forming polymer compound includes a fluorine-based compound, the fluorine-based compound is polytetrafluoroethylene (PTFE)-based, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA)-based, tetrafluoro Roethylene-hexafluoropropylene copolymer (FEP) type, tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer (EPE) type, tetrafluoroethylene-ethylene copolymer (ETFE) type, It may include any one or more compounds selected from the group consisting of polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), and polyvinylidene fluoride (PVDF).

In addition, the nanofiber may include a first polymer compound that is a hydrophobic polymer compound, and the coating layer may include a second polymer compound that is a hydrophilic polymer compound.

In addition, the nanofiber web may be an air electrospun nanofiber web.

In addition, the nanofiber web is disposed above and below the first support, respectively, and may further include a porous second support interposed between the first support and the nanofiber web, respectively.

In addition, the thickness of the first support may be 90% or more of the total thickness of the filter medium.

In addition, the first support and the second support may be any one of a nonwoven fabric, a woven fabric, and a knitted fabric.

In addition, the basis weight of the first support may be 250 ~ 800 g / m 2 , and the thickness may be 2 ~ 8 mm.

In addition, including a support component and a low melting point component, at least a portion of the low melting point component is provided with a second composite fiber disposed to be exposed to the outer surface, the low melting point component of the second composite fiber to be fused to the nanofiber web can

In addition, the first support of the filter media includes a first composite fiber disposed such that at least a portion of the low-melting-point component is exposed on the outer surface, including a support component and a low-melting-point component, and the low-melting point of the first composite fiber The first support and the second support may be bound by fusion between the component and the low-melting component of the second composite fiber.

In addition, the nanofiber web may have an average pore diameter of 0.1 to 3 μm, and a porosity of 60 to 90%.

In addition, the nanofibers forming the nanofiber web may have an average diameter of 50 to 450 nm.

In addition, the second support may have a basis weight of 35 to 80 g/m 2 and a thickness of 150 to 250 μm.

In addition, the present invention, (1) by spinning a first spinning solution containing a functional material through the outer tube of the spinning nozzle including the inner tube and the outer tube, the nanofibers formed of the coating layer containing the functional material is formed manufacturing a fiber web; And (2) disposing the nanofiber web on both sides of the first support; It provides a method of manufacturing a filter medium comprising a.

According to an embodiment of the present invention, the spinning nozzle further includes an outermost tube, and in step (1), air is further sprayed into the outermost tube to manufacture a nanofiber web.

In addition, the step (2) further comprises laminating the second support and the nanofiber web, both surfaces of the first support so that the second support of the laminated second support and the nanofiber web comes into contact with the first support. can be placed in

In addition, in step (1), a second spinning solution containing the first fiber-forming polymer compound is spun into the inner tube, and a second fiber-forming polymer compound and a functional polymer compound containing at least one of a functional material as a functional material. One spinning solution may be spun into the outer tube.

In addition, the present invention provides a plate-type filter unit including a support frame for supporting the edge of the filter medium and having a flow path through which the filtrate filtered from the filter medium and the filter medium flows out to the outside.

In addition, the present invention provides a filter module provided with the plurality of plate-type filter units spaced apart from each other at a predetermined interval.

According to the present invention, various functions can be implemented complexly in a single filter medium by using a polymer compound having different functions as a fiber-forming component or a functional additive, and the thickness of the nanofiber constituting the nanofiber web and the size of the pores is uniform, and can significantly reduce the yarn breakage rate of nanofibers. In addition, the shape, structural deformation, and damage of the filter medium during water treatment operation are minimized, and the flow path is smoothly secured to have a high flow rate. In addition, it has an extended use cycle due to the excellent durability of the filter media even at high pressure applied during backwashing, and at the same time has improved hydrophilic properties and excellent water permeability, so it can be applied in various water treatment fields.

1A to 1C are views of a filter medium according to an embodiment of the present invention. FIG. 1A is a cross-sectional view showing a filter medium having nanofiber webs disposed on both sides of a first support, and FIG. 1B is a second support. It is a cross-sectional view of the filter medium further comprising, Figure 1c is a perspective view showing the nanofiber including the coating layer,
2 is a photograph of the filter medium in which the washing liquid is trapped inside the filter medium and swells after the layers are separated inside the filter medium by the backwashing process;
Figure 3 is a schematic view showing that the first support and the nanofiber web directly laminated;
4A and 4B are schematic views of laminating a filter medium according to an embodiment of the present invention, FIG. 4A is a view showing laminating a nanofiber web and a second support, and FIG. 4B is a laminated nanofiber web and a second support. 2 A view showing the lamination by placing the support on both sides of the first support,
5a to 5b are views of a nanofiber web included in an embodiment of the present invention, FIG. 5a is a surface electron micrograph of the nanofiber web, and FIG. 5b is a cross-sectional electron micrograph of the nanofiber web, FIG. 5c is a graph for the fineness distribution of nanofibers provided in the nanofiber web, FIG. 5d is a graph for the pore diameter distribution of the nanofiber web,
6 is a cross-sectional electron microscope photograph of a filter medium included in an embodiment of the present invention;
7a is a perspective view of the filter unit, FIG. 7b is a schematic view showing the filtration flow based on a cross-sectional view taken along the boundary line XX' of FIG. 7a, and
8 is a schematic diagram illustrating a double nozzle according to an embodiment of the present invention, and FIG. 8b is a schematic diagram illustrating a triple nozzle according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are added to the same or similar elements throughout the specification. In addition, the term "nano" as used herein refers to a nano scale, and may include a micro unit. In the present invention, a structure in which a plurality of nanofibers are spun from a spinning solution through electrospinning to form a structure is defined as a nanofiber web, and an empty space between the nanofiber webs constituting the nanofiber separation membrane is defined as a pore. In addition, the pore size, thickness and porosity of the nanofiber-graphene separator for water treatment of the present invention are defined as the pore size, thickness and porosity after the nanofiber web is laminated and heat-treated.

1A to 1C, the filter medium 1000 according to an embodiment of the present invention is disposed on a porous first support 130 and one surface of the first support 130, and includes a functional material. The coating layer (111a ₁ , 112a ₁ ) is implemented as a nanofiber web (111, 112) of a three-dimensional network structure formed by the nanofibers (111a, 112a) surrounding the outer surface.

In this case, the nanofiber webs 111 and 112 may be respectively disposed on the upper and lower portions of the first support 130 , and a porous second interposed between the first support 130 and the nanofiber webs 111 and 112 , respectively. Supports 121 and 122 may be further included, and in this case, the filtrate filtered from the nanofiber webs 111 and 112 may have a filtration flow flowing in the direction of the first support 130 .

In general, materials used for filtration media of filter media for water treatment such as the nanofiber webs 111 and 112 are polyamide (PA), polyethylene (PE), polypropylene (PP), polyvinylidene fluoride (PVDF), poly Polymer compounds such as sulfone (PSF), cellulose acetate (CA), and Teflon (PTFE) or ceramics or metals can be selected. % or more of high molecular weight compounds.

At this time, since the performance of the filter medium implemented with the polymer compound is determined by the water permeability and selectivity of the filter medium, it is possible to improve the efficiency of the filter medium by efficiently selecting the polymer compound having various functionalities. In other words, it is possible to improve the efficiency of filter media by realizing a multifunctional filtration medium in which various functions are complex by using high molecular compounds having different functions as fiber-forming components or functional additives.

Accordingly, in the filter medium 1000 according to the present invention, the nanofibers (111a, 112a) include a first fiber-forming polymer compound, and the coating layer (111a ₁ , 112a ₁ ) is a second fiber-forming polymer compound and a functional polymer By being implemented to include one or more polymer compounds among the compounds, it is possible to prevent deterioration of each physical property due to non-uniform mixing of different polymer compounds, and further, nanofibers (111a, 112a) and coating layers (111a ₁ , 112a ₁ ) At least two types of polymer compounds having the functionality to improve the efficiency of the filter media by uniformly mixing different polymer compounds separately from each other based on the interface of the filter media can be implemented in a single media.

In this case, the functional additive interacts with external factors such as mechanical strength, ion exchange properties, immobilized catalytic enzyme properties, separability, dispersibility and selective permeability, as well as functionality expressed by the properties of the polymer compound itself, such as heat resistance and chemical resistance. It may be a known functional additive having functionality expressed through action. That is, the functional additive may be an additive selected from the group consisting of a heat resistance improver, a dispersant, a chemical resistance improver, a strength enhancer, a catalyst, a separation enhancer, and a permeability improver, or an additive including at least one of them.

In addition, as the first fiber-forming polymer compound, a known fiber-forming component for forming the nanofibers 111a and 112a may be used, and in particular, a fiber-forming component including a fluorine-based compound may be selected. The fluorine-based compound is, for example, polytetrafluoroethylene (PTFE)-based, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA)-based, tetrafluoroethylene-hexafluoropropylene copolymer (FEP)-based , tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer (EPE)-based, tetrafluoroethylene-ethylene copolymer (ETFE)-based, polychlorotrifluoroethylene (PCTFE)-based, chlorotri It may contain any one or more compounds selected from the group consisting of fluoroethylene-ethylene copolymer (ECTFE)-based and polyvinylidene fluoride (PVDF)-based, more preferably nanofibers ( 111a, 112a) may be easily mass-produced, and may be polyvinylidene fluoride (PVDF) in terms of excellent mechanical strength and chemical resistance. At this time, when the nanofibers 111a and 112a include PVDF as a fiber-forming component, the weight average molecular weight of the PVDF may be 10,000 to 1,000,000, preferably 300,000 to 600,000, but is not limited thereto.

On the other hand, in general, a filter medium formed of nanofibers electrospun with polyvinylidene fluoride (PVDF) as a fiber-forming component has excellent chemical resistance due to its hydrophobic properties, but has poor affinity for water, There is a problem that the transmittance is lowered. In order to solve this problem, research on hydrophilized or wet out treatment that gives hydrophilic properties to filter media has been introduced, but mechanical strength and thermal stability because water molecules can act as plasticizers. There are aspects that are not suitable for this demanding filter field. Similarly, there is a chemical modification method for imparting hydrophilic properties to the filtration medium, but there may be problems with the uniformity and durability of the surface, and there is a problem in that productivity is reduced in that an additional post-treatment process must be performed, and it takes a long time. Furthermore, in the case of chemically modified filter media, there may be aspects if it is disadvantageous in terms of mechanical strength and chemical stability.

Accordingly, the present invention is an embodiment, and in order to realize a filtration medium having both the hydrophilic and hydrophobic properties described above, the nanofibers 111a and 112a and the coating layers 111a ₁ and 112a ₁ are each formed of a first polymer compound. and a second polymer compound, wherein the first polymer compound comprises a hydrophobic polymer compound, and the second polymer compound comprises a hydrophilic polymer compound. In this case, by simultaneously expressing hydrophilicity and hydrophobicity without going through an additional hydrophilicization process or chemical modification process, a filter medium that exhibits water permeability and filtration efficiency above a certain level and at the same time can guarantee chemical resistance, heat resistance and mechanical strength. It can be implemented to improve the usability in more diverse industries.

In this case, the fiber-forming component included in the above-described first polymer compound exhibits hydrophobic properties, does not cause deterioration in water permeability and selectivity of the filter medium, and does not affect durability and mechanical strength of the filter medium. It can be used without this limitation. For example, a fiber-forming component including any one or more polymer compounds selected from polyvinylidene fluoride, polyethylene sulfone, polyurethane, and the like may be selected.

In addition, the fiber-forming component included in the second polymer compound has a hydrophilic property, and as described above, a known fiber-forming component may be used in a range that does not affect the physical properties of the filtration medium. For example, a fiber-forming component including any one or more polymer compounds selected from polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide, and the like may be selected.

As described above, the filter media according to an embodiment of the present invention uses a nanofiber web (111, 112) implemented with a coating layer (111a ₁ , 112a ₁ ) having hydrophilic properties and nanofibers (111a, 112a) having hydrophobic properties as a filter medium. By using it, it is possible to realize a multifunctional filter medium that can simultaneously utilize the advantages of a hydrophobic filtration medium and a hydrophilic filtration medium. That is, according to the above-described embodiment of the present invention, excellent chemical, thermal and biological stability or mechanical strength as a hydrophobic filtration medium can be guaranteed, and easy control of contaminants as a hydrophilic filtration medium and high water permeability It is possible to implement a multifunctional filter media that simultaneously expresses itself.

At this time, the average diameter of the nanofibers 111a, 112b and the diameter of the coating layer 111a ₁ , 112a ₁ may have a ratio of 1: 0.2 to 0.8, preferably 1: 0.3 to 0.6. there is. As described above, according to an embodiment, when the nanofibers 111a and 112a and the coating layers 111a ₁ and 112a ₁ each contain a hydrophobic and hydrophilic polymer compound, the characteristics of the hydrophobic filter medium and the hydrophilic filter medium In order to express all the characteristics of the nanofibers 111a and 112b, the diameters of the nanofibers 111a and 112a and the coating layers 111a ₁ and 112a ₁ constituting the nanofibers 111a and 112b must have a constant ratio. That is, if the nanofibers (111a, 112a) and the diameter of the coating layer (111a ₁ , 112a ₁ ) have a ratio of 1: 0.2 or less, the content of the hydrophilic polymer compound forming the coating layer (111a ₁ , 112a ₁ ) is Due to insignificance, chemical and mechanical stability may be lowered, and there may be problems in durability and stability of filter media. In addition, if the nanofibers (111a, 112b) diameter and the diameter of the coating layer (111a ₁ , 112a ₁ ) have a ratio of 1: 0.8, the content of the hydrophilic polymer compound constituting the nanofibers (111a, 112a) can be It may not be possible to improve the transmittance as much as desired, and may be relatively disadvantageous in controlling contaminants.

Meanwhile, the nanofiber webs 111 and 112 according to the present invention may be air electrospun nanofiber webs 111 and 112 . That is, in the present invention, when electrospinning is performed by air electrospinning according to a manufacturing method to be described later, air is sprayed from the outer periphery of the spinning nozzle, so that the air is collected and accumulated by the spinning solution composed of highly volatile fiber-forming components. , it is possible to produce the nanofiber webs 111 and 112 with higher mechanical strength, and it is possible to minimize the spinning troubles that may occur due to the flying of nano-scale microfibers. Furthermore, by adjusting the air injection pressure or the injection conditions of temperature and humidity, the size and porosity of the pores of the nanofiber webs 111 and 112 can be easily controlled, and through this, the water permeability and mechanical strength of the filter media are targeted. can be chosen to suit the

In addition, when the nanofiber web (111, 112) is formed by spinning by the air electrospinning method, the coating layer (111a ₁ , 112a ₁ ) formed on the nanofiber (111a, 112a) forming the nanofiber web (111, 112) The thickness of can be implemented uniformly.

At this time, the nanofiber webs 111 and 112 may be divided into first to third regions in the thickness direction from the surface in contact with the first support, and the first to third regions are represented by the following Equations 1 to Mathematical expressions. Each of the values of Equation 3 may be 0.98 to 1.02.

[Equation 1]

[Equation 2]

[Equation 3]

If the values of Equations 1 to 3 are less than 0.97 or exceed 1.02, the thickness of the nanofibers (111a, 112a) and the coating layers (111a ₁ , 112a ₁ ) in each region is different due to water permeability, contamination It may be difficult to easily control material processing and the like, and furthermore, it may not be easy to quantitatively control the advantageous effects of the polymer compounds having different functions targeted by the present invention.

In addition, in the first to third regions, the values of Equations 4 to 6 may be 0.98 to 1.02, respectively.

[Equation 4]

[Equation 5]

[Equation 6]

In general, the uniformity of the average pore diameter of the fiber web can be one indicator that the nanofibers are uniformly spun without being trimmed in the spinning process. As is emitted to have a smooth surface without trimming, the values of Equations 4 to 6 may satisfy 0.98 to 1.02. That is, because the average pore diameter in each area of the nanofiber webs 111 and 112 is uniform and the nanofibers 111a and 112a are not trimmed, the water permeability as a filtration medium is improved and the prediction of contaminant treatment performance can be improved. Furthermore, it may be more advantageous to quantitatively control the advantageous effects of the polymer compounds having different functions for which the present invention is desired.

In addition, the nanofibers 111a and 112a may have an average diameter of 0.05 to 1 μm, and an aspect ratio of 1,000 to 100,000, but are not limited thereto. For example, the nanofibers 111a and 112a provided in the nanofiber webs 111 and 112 include a first group of nanofibers having a diameter of 0.1 to 0.2 μm, a second group of nanofibers having a diameter of 0.2 to 0.3 μm, and a diameter of 0.3 The third group of nanofibers of ~0.4㎛ may be included in an amount of 35% by weight, 53% by weight, and 12% by weight, respectively, based on the total weight of the nanofiber web 111 .

The above-described nanofiber webs 111 and 112 may have a thickness of 0.5 to 200 μm, for example, 20 μm. The porosity of the nanofiber webs 111 and 112 may be 40 to 90%, more preferably 60 to 90%. In addition, the average pore diameter may be 0.1 ~ 5㎛, more preferably 0.1 ~ 3㎛, for example, may be 0.25㎛. The basis weight of the nanofiber webs 111 and 112 may be 0.05 to 20 g/m 2 , and may be, for example, 10 g/m 2 , but is not limited thereto, and may be appropriately changed in consideration of the desired water permeability and filtration efficiency.

In addition, the nanofiber webs 111 and 112 may be provided in the filter medium 1000 in one or more layers, and in this case, the porosity, pore size, basis weight and/or thickness of each nanofiber web may be different.

Hereinafter, other configurations provided in the filter medium 1000 will be described in detail.

First, the first support 130 serves to support the filter medium 1000 and form a large flow path to more smoothly perform the filtering process or the backwashing process. Specifically, in the filtration process, if a pressure gradient is formed so that the pressure inside the filter medium is lower than that outside, the filter medium may be compressed. In this case, the flow path through which the filtrate can flow inside the filter medium is significantly reduced or blocked. There is a problem that a larger differential pressure is applied to the filter medium and the flow rate may be significantly lowered. In addition, in the backwashing process, an external force that expands from the inside to the outside of the filter medium may be applied, but if the mechanical strength is low, there may be a problem in that the filter medium is damaged due to the external force applied.

The first support 130 is provided to prevent the above problems occurring in the filtration process and/or backwashing process, and may be a known porous member that is used in the water treatment field and guarantees mechanical strength. 1 The support may be a nonwoven fabric, a woven fabric or a fabric.

The fabric means that the fibers included in the fabric have a vertical and horizontal direction, and specific structures may be plain weave, twill, etc., and the density of warp and weft yarns is not particularly limited. In addition, the knitted fabric may be a known knitted structure, may be a weft knitted fabric, a warp knitted fabric, etc., for example, may be a tricot in which the yarn is warp knitted. In addition, as shown in FIGS. 1A and 1B , the first support 130 may be a nonwoven fabric having no longitudinal and transverse direction to the fibers 130a, chemical bonding nonwoven fabric, thermal bonding nonwoven fabric, dry nonwoven fabric such as airlay nonwoven fabric or wet nonwoven fabric, A known nonwoven fabric manufactured by various methods such as spanless nonwoven fabric, needle punching nonwoven fabric or melt blown may be used.

The first support 130 may occupy a thickness of 90% or more of the total thickness of the filter medium as described above in order to express sufficient mechanical strength. For example, the thickness of the first support 130 may be 2 to 8 mm, more preferably 2 to 5 mm, even more preferably 3 to 5 mm. If the thickness is less than 2 mm, it may not develop sufficient mechanical strength to withstand frequent backwashing. In addition, when the thickness exceeds 8 mm, when a plurality of filter units are implemented as a filter module of a limited space after the filter media is implemented as a filter unit to be described later, the degree of integration of the filter media per unit volume of the module may be reduced.

Preferably, the first support 130 may have a basis weight of 250 to 800 g/m2, more preferably 350 to 600 g/m2, while satisfying the thickness conditions as described above. If the basis weight is less than 250 g/m2, it may be difficult to express sufficient mechanical strength, and there is a problem in that the adhesion with the second support is reduced. In addition, there may be a problem in that smooth backwashing is difficult due to an increase in differential pressure.

In addition, when the first support 130 is formed of fibers such as a nonwoven fabric, the average diameter of the fibers may be 5 to 50 μm, preferably 20 to 50 μm. In addition, the first support 130 may have an average pore diameter of 20 to 200 μm, and a porosity of 50 to 90%, but is not limited thereto, and nanofibers to be described later in the filtering process and/or backwashing process. There is no limitation as long as the porosity and pore size are sufficient to support the webs 111 and 112 to express a desired level of mechanical strength and to smoothly form a flow path even at high pressure.

When the first support 130 is a material used as a support for the separation membrane, there is no limitation in the material thereof. Non-limiting examples thereof include a synthetic polymer component selected from the group consisting of polyester, polyurethane, polyolefin and polyamide; Alternatively, a natural polymer component including cellulose may be used. However, if the first support has strong brittle physical properties, it may be difficult to expect a desired level of binding force in the process of laminating the first support and the second support, which means that the first support has a smooth surface like a film. Rather, the surface may be macroscopically rough while forming porosity, and the surface formed of fibers such as a nonwoven fabric may not have a smooth surface depending on the arrangement of the fibers and the fineness of the fibers, and the degree may be different depending on the location. am. If the remaining parts are joined while the non-adherent part exists at the interface between the two layers to be laminated, interlayer separation may start due to the non-adherent part. In order to solve this problem, it is necessary to perform the lamination process in a state where the degree of adhesion between the two layers is increased by applying pressure from both sides of the two layers. There is a limit in heightening, and since the support may be damaged if a greater pressure is applied, the material of the first support may be suitable for a material having good flexibility and high elongation, and preferably has excellent adhesion to the second support 121 and 122 The first support 130 may be made of a polyolefin-based material.

Meanwhile, the first support 130 may include a low-melting component in order to be bound to the second supports 121 and 122 without a separate adhesive or adhesive layer. When the first support 130 is a fabric such as a nonwoven fabric, it may be made of the first composite fiber 130a including a low melting point component. The first composite fiber 130a may include a support component and a low-melting-point component, and may be arranged such that at least a portion of the low-melting-point component is exposed to the outer surface. For example, a sheath-core type composite fiber in which a support component forms a core portion and a low melting point component forms a sheath portion surrounding the core portion, or a side-by-side composite fiber in which a low melting point component is disposed on one side of the support component can be As described above, the low-melting component and the supporting component may be preferably polyolefin-based in terms of flexibility and elongation of the support, for example, the supporting component may be polypropylene, and the low-melting component may be polyethylene. The melting point of the low melting point component may be 60 ~ 180 ℃.

Next, the second supports 121 and 122 that may be disposed on both surfaces of the above-described first support 130 will be described.

The second supports 121 and 122 support the nanofiber webs 111 and 112 to be described later, and serve to increase the bonding strength of each layer provided in the filter medium.

The second supports 121 and 122 are not particularly limited as long as they normally serve as support for the filter media, but may preferably be woven, knitted or non-woven in shape. The fabric means that the fibers included in the fabric have a vertical and horizontal direction, and specific structures may be plain weave, twill, etc., and the density of warp and weft yarns is not particularly limited. In addition, the knitted fabric may be a known knitted fabric, and may be a weft knitted fabric, a warp knitted fabric, or the like, but is not particularly limited thereto. In addition, the nonwoven fabric means that there is no longitudinal and lateral direction in the fibers contained therein, and known such as chemical bonding nonwoven fabric, thermal bonding nonwoven fabric, dry nonwoven fabric or wet nonwoven fabric such as airlay nonwoven fabric, spanless nonwoven fabric, needle punching nonwoven fabric or melt blown nonwoven fabric A nonwoven fabric manufactured by the method described above may be used.

The second supports 121 and 122 may be, for example, non-woven fabrics. In this case, the fibers forming the second supports 121 and 122 may have an average diameter of 5 to 30 μm. In addition, the thickness of the second supports (121, 122) may be 100 ~ 400㎛, more preferably 150 ~ 400㎛ may be, even more preferably 150 ~ 250㎛ may be, for example, 200㎛ can

Also, the second supports 121 and 122 may have an average pore diameter of 20 to 100 μm, and a porosity of 50 to 90%. However, it is not limited thereto, and it supports the nanofiber webs 111 and 122 to be described later to express a desired level of mechanical strength and at the same time not to inhibit the flow of the filtrate flowing through the nanofiber webs 111 and 122. There is no limitation as far as porosity and pore size are concerned.

In addition, the basis weight of the second supports 121 and 122 may be 10-200 g/m2, more preferably 35-200 g/m2, even more preferably 35-80 g/m2, for example, 40 g/m2 It can be m2. If the basis weight is less than 10 g / ㎡, the amount of fibers forming the second support distributed at the interface formed with the nanofiber webs 111 and 112 to be described later may be small, and accordingly, effective adhesion of the second support in contact with the nanofiber web Due to the reduction of the area, it may not be possible to express a desired level of binding force. In addition, it may not be able to express sufficient mechanical strength to support the nanofiber web, there may be a problem in that the adhesion to the first support is reduced. In addition, if the basis weight exceeds 200 g/m 2 , it may be difficult to secure a desired level of flow, and there may be a problem in that smooth backwashing is difficult due to an increase in differential pressure.

When the second supports 121 and 122 are a material used as a support for the filter medium, there is no limitation in the material thereof. Non-limiting examples thereof include a synthetic polymer component selected from the group consisting of polyester-based, polyurethane-based, polyolefin-based and polyamide-based; Alternatively, a natural polymer component including cellulose may be used.

However, the second supports 121 and 122 may be polyolefin-based polymer components to improve adhesion between the nanofiber webs 111 and 112 and the first support 130 to be described later. In addition, when the second supports 121 and 122 are fabrics such as nonwoven fabrics, they may be made of the second composite fibers 121a including a low melting point component. The second composite fiber 121a may include a support component and a low-melting-point component, and may be arranged such that at least a portion of the low-melting-point component is exposed to the outer surface. For example, a sheath-core type composite fiber in which a support component forms a core portion and a low melting point component forms a sheath portion surrounding the core portion, or a side-by-side composite fiber in which a low melting point component is disposed on one side of the support component can be As described above, the low-melting component and the supporting component may be preferably polyolefin-based in terms of flexibility and elongation of the support, for example, the supporting component may be polypropylene, and the low-melting component may be polyethylene. The melting point of the low melting point component may be 60 ~ 180 ℃.

If the above-described first support 130 is implemented as a first composite fiber 130a including a low-melting component in order to express a more improved bonding force with the second support 130, the first support 130 and the first A more robust fusion portion may be formed at the interface between the two supports 121 due to fusion of the low-melting-point component of the first composite fiber 130a and the low-melting-point component of the second composite fiber 121a. In this case, the first composite fiber 130a and the second composite fiber 121a may be made of the same material in terms of compatibility.

On the other hand, as the water treatment process using filter media is repeated, foreign substances contained in the water to be treated adhere to the filter media to form an adhesion layer or become lodged inside the filter media to block the flow path and reduce the filtration function. When the filter media is replaced, there is a problem in that the cost of water treatment increases. Accordingly, in order to extend the use cycle of the filter medium, it is necessary to periodically apply a physical stimulus to the filter medium to perform a cleaning process to remove foreign substances adhering to or embedded in the filter medium, which is called backwashing. In general, backwashing removes foreign substances attached to or embedded in the filter media by strongly flowing washing water or blowing air in the direction opposite to the filtration direction of the filter media. It is necessary to supply washing water or air at a pressure higher than the pressure applied to the filter media in the filtration process in order to remove it.

Accordingly, in order for the filter media to retain the backwashing ability, it is important to have mechanical strength enough to not deform or damage the filter media even under high pressure applied, and a support for supplementing the mechanical strength is usually provided in the filter media. . Factors that can affect the mechanical strength of the support include the structure of the support, for example, when the support is a non-woven fabric, the diameter of the fibers forming the non-woven fabric, the length of the fibers, the bonding method between fibers, the thickness, the basis weight, and the thickness As the thickness or basis weight increases, the mechanical strength of the support may increase. Therefore, as an example for designing a filter medium resistant to backwashing, a thick nonwoven fabric may be used, or a nonwoven fabric having a very large basis weight may be used as a support even if the thickness is somewhat thin.

On the other hand, it is preferable that the support has a large pore diameter so as not to affect the flow of the filtrate of the filter medium. It is very undesirable for the flow rate to be lowered due to the support provided to supplement the mechanical strength as it reduces the main physical properties of the filter medium. However, when a nonwoven fabric that exhibits sufficient mechanical strength despite its thin thickness is used as a support, the diameter and porosity of the pores in the nonwoven fabric are remarkably small as the basis weight of the nonwoven fabric is very large, and as it affects the filtrate flow of the filter media, There is a problem in that it is not possible to secure a desired level of flow rate.

Accordingly, in the filter media 1000 according to the present invention, in order to secure a sufficient flow path and guarantee the mechanical strength of the filter media, the first support 130 may have a thickness of 90% or more of the entire filter media as described above, and the The thickness of the first support 130 is preferably 95% or more of the total thickness of the filter medium, more preferably 98 to 99.9%. If the first support is less than 90% of the total thickness of the filter medium, the filter medium does not have sufficient mechanical strength and it is difficult to perform backwashing, so the replacement cycle of the filter medium may be shortened. In addition, it is very desirable that the first support is less than 90% of the total thickness of the filter media and that it has sufficient mechanical strength to withstand backwashing because the flow of the filtrate due to the first support may be disturbed and the flow rate may be reduced. Can not do it.

However, when the bonding force between the nanofiber webs 111 and 112 functioning as a filter material and the first support 130 is weak, the durability of the filter material according to backwashing may be reduced even though the mechanical strength is very excellent. That is, the high pressure applied during the backwashing process may accelerate the interfacial separation between the layers forming the filter medium, and in this case, as shown in FIG. As a separator, there is a problem that the function may be significantly reduced or completely lost.

Therefore, high adhesion between the first support with significantly increased thickness and the nanofiber web as a filter medium is very important in realizing a filter medium that exhibits sufficient durability even in frequent backwashing.

In general, in the method of attaching the support and the nanofiber web, the two layers can be joined by using a separate adhesive material or by fusing a low-melting component provided in the support to the nanofiber web. However, when the two layers are joined through a separate bonding material, the bonding material may be dissolved by the water to be treated, which may cause contamination of the filtrate and a decrease in water permeability. If the filter media in which the bonding material is partially dissolved is backwashed, the filter media may become full or, in severe cases, the nanofiber web may be peeled off and completely lose its function as a filter media.

Accordingly, it is preferable to adopt a method in which the nanofiber web and the support are joined through fusion (A), and heat and / or They can be joined by applying pressure. However, the point to be considered when joining them by applying heat and/or pressure is to minimize the physical and chemical transformation of the nanofiber web 2 functioning as a filter material due to the applied heat and pressure, and if the thermal bonding process In the case of physical and chemical transformation of the nanoweb, there is a problem that the physical properties such as flow rate and filtration rate of the initially designed filter media may be changed.

The point to be considered when selecting heat and/or pressure conditions in the attachment process so that there is no physical/chemical deformation of the nanofiber web 2 may be the material properties of the nanofiber web and the support, for example, the melting point, thermal conductivity, heat capacity, etc. , usually by simultaneously applying a temperature above the melting point or a temperature and pressure above the melting point to fuse the low-melting component of the support to the nanofiber web, or apply a high pressure even if it is slightly lower than the melting point to fuse the low-melting component of the support to the nanofiber web. there is.

On the other hand, the material for forming the support or the nanofiber web is a high molecular compound, and since such a high molecular compound has low thermal conductivity and a very large heat capacity, as shown in FIG. 3 , even when a predetermined heat (H ₁ , H ₂ ) is applied to both sides Heat (H ₁ , H ₂ ) reaches the interface between the nanofiber web 2 and the support 1 to increase the temperature of the low-melting-point component provided in the support 1 to the melting point. this should be applied Moreover, when the thickness of the support 1 is very thick as shown in FIG. 3 , the heat (H ₂ ) transferred from the bottom is transmitted to the vicinity of the interface between the nanofiber web 2 and the support 1, and the low provided in the support in the vicinity thereof. It may take a longer time to raise the temperature of the melting point component to the melting point, and it is necessary to apply more heat from the bottom to shorten the time. However, when too much heat is applied from below, the melting of the low-melting-point component may occur first in the lower portion of the first support, and there is a problem that the shape and structure of the support may be changed.

In another method, it is possible to solve the difficulties depending on the thickness of the support 1 by increasing the heat H1 applied from above, but in this case, physical/chemical deformation of the nanofiber web 2 may result, and There is a problem that the physical properties of the designed filter media may not be fully expressed.

Accordingly, the filter medium 1000 according to an embodiment of the present invention does not directly face the first support 130 and the nanofiber webs 111 and 112, but interposes the thinner second support 121 and 122. , through which the interlayer adhesion process can be performed more stably and easily, exhibit remarkably excellent bonding strength at the interface between each layer, and minimize interlayer separation and peeling problems even when a high external force is applied due to backwashing.

4A, the difference in thickness between the nanofiber web 2 and the nanofiber web 2 of the second support 3, which accounts for less than 10% of the total thickness of the filter medium, is the nanofiber web 2 and the first support 1 ), as compared to the thickness difference between them, the heat (H ₁ , H ₂ ) applied from above and below the laminate of the nanofiber web (2)/second support (3) reaches the interface between them, and the fusion part ( B) is easier to form compared to FIG. 3 . In addition, as it is easier to control the amount and time of applied heat compared to FIG. 3 , it is advantageous to prevent physical/chemical deformation of the nanofiber web 2 , as shown in FIGS. 4A and 4B , the second support 3 When the nanofiber web 2 is bonded to the nanofiber web 2, there is an advantage in that the nanofiber can be bonded to the support with excellent adhesion without changing the physical properties of the initially designed nanofiber web 2 .

The above-described filter media 1000 may be manufactured by a manufacturing method described later, but is not limited thereto.

The filter medium 1000 according to the present invention (1) radiates a first spinning solution containing a functional material through an outer tube of a spinning nozzle including an inner tube and an outer tube, and a coating layer containing a functional material is formed. It is implemented including the steps of manufacturing a nanofiber web formed of fibers and (2) disposing the nanofiber web on both sides of the first support.

First, in the step (1) according to the present invention, (1) a first spinning solution containing a functional material is spun through the outer tube of the spinning nozzle including the inner tube 10 and the outer tube 20, A step of preparing a nanofiber web formed of nanofibers having a coating layer including a material is performed.

A method for manufacturing a nanofiber having a coating layer according to the present invention has a clear boundary, and a known spinning method that prevents different polymer compounds from being mixed and spun can be used. It can be manufactured by performing double nozzle electrospinning as described above. That is, a double nozzle having an inner tube 10 and an outer tube 20 provided on the outside of the inner tube 10 is prepared with each spinning solution so that different polymer compounds are not mixed, and different spinning solutions are used. Electrospinning can be performed by discharging through it. In this case, different high molecular compounds spun through the inner tube 10 and the outer tube 20 do not mix with each other and a nanofiber web implemented with nanofibers forming an interface can be manufactured.

In this case, the nanofiber is implemented by being discharged through the inner tube as a second spinning solution containing the first fiber-forming polymer compound, and the coating layer is a second fiber-forming polymer compound and/or a functional material containing a functional polymer compound. As the first spinning solution including At least two or more types of high molecular compounds each having the functionality of being separated and uniformly mixed to improve the efficiency of the filter medium can be implemented in a single filter medium.

For example, the second spinning solution spun through the inner tube 10 may include polyvinyl fluoride as a hydrophobic fiber-forming component, and the first spinning solution spun through the outer tube 20 is a hydrophilic fiber It may include polyvinyl alcohol as a forming component.

In this case, the content of the hydrophilic fiber-forming component, the hydrophobic fiber-forming component, and the solvent may be selected to be appropriate for an industrial group for which the hydrophilic and hydrophobic properties of the prepared filter media are desired, but is not particularly limited, but for example, the hydrophilic fiber-forming component and the Hydrophobic fiber-forming component 1: It may have a weight ratio of 0.2 to 1.5. In another embodiment, the spinning solution may include a fluorine-based compound as a fiber-forming component, and the fluorine-based compound is preferably included in the spinning solution in an amount of 5 to 30% by weight, preferably 8 to 20% by weight, and if the fluorine-based compound is If it is less than 5% by weight, it is difficult to form into fibers, and when spinning, it is not spun into fibers but is sprayed in the form of droplets to form a film or even when spinning, a lot of beads are formed and the solvent is not volatilized well, so calendering to be described later In the process, clogging of pores may occur. In addition, if the fluorine-based compound exceeds 30% by weight, the viscosity rises and solidification occurs on the surface of the solution, making it difficult to spin for a long time, and the fiber diameter may increase so that it may not be possible to make a fibrous shape having a size of micrometers or less.

In addition, according to an example, the first spinning solution and the second spinning solution may further include a solvent.

The solvent may be used without limitation in the case of a solvent that does not form a precipitate while dissolving the fiber-forming component and does not affect the radioactivity of nanofibers to be described later, but is preferably γ-butyrolactone, cyclohexanone, 3-hexanone , 3-heptanone, 3-octanone, N-methylpyrrolidone, dimethylacetamide, acetone dimethylsulfoxide, may include any one or more selected from the group consisting of dimethylformamide. For example, the solvent may be a mixed solvent of dimethylacetamide and acetone.

The prepared spinning solution may be manufactured into nanofibers through a known electrospinning device and method. For example, the electrospinning device uses an electrospinning device having a single spinning pack with one spinning nozzle, or is mass-produced. For this purpose, an electrospinning device having a plurality of single spinning packs or a spinning pack having a plurality of nozzles may be used. In addition, in the electrospinning method, dry spinning or wet spinning having an external coagulation bath can be used, and there is no limitation according to the method.

In this case, the spinning nozzle in step (1) may be a triple nozzle further comprising an outermost tube, and further spraying air to the outermost tube may spin nanofibers. That is, by air electrospinning by providing the outermost tube 30 that radiates air to the outside of the outer tube 20 as shown in FIG. 8b, each region (first to first to) according to the thickness of the nanofiber web as described above The thickness of the nanofibers and the coating layer included in the third region) can be uniformly formed, and the nanofibers are prevented from breaking due to the air emitted through the outermost tube 30 and at the same time, the surface roughness is controlled so that the surface is smooth. Nanofibers can be obtained.

Next, as the step (2) according to the present invention, the step of laminating the first support on one surface of the prepared nanofiber web is performed. At this time, before performing the step (2), (2-1) laminating the nanofiber web and the second support and (2-2) laminating the second support on both sides of the first support so that the second support comes into contact with the first support. It may be carried out including the step of disposing the nanofiber web and the second support.

First, in the step of (2-1) laminating the nanofiber web and the second support, when the second support is implemented as a low-melting composite fiber, thermal fusion of the nanofiber web and the second support is performed through the calendering process. Binding can be carried out simultaneously.

In addition, a separate hot melt powder or hot melt web may be further interposed in order to bind the second support and the nanofiber web. At this time, the applied heat may be 60 ~ 190 ℃, the pressure may be applied at 0.1 ~ 10kgf / ㎠, but is not limited thereto. However, components such as hot melt powder, which are added separately for binding, generate hum or are melted in the laminating process between supports and between supports and nanofibers to close pores frequently, so that the flow rate of the first designed filter media is achieved. may not be able to In addition, it is preferable to bind the second support and the nanofiber web without including it because it can be dissolved in the water treatment process and cause negative environmental problems.

Next, as the step (2) according to the present invention, the step of laminating the first support on one surface of the prepared nanofiber web is performed. In this case, the step (2), (2-1) laminating the second support and the nanofiber web, and further comprising the step of arranging the first support on both sides of the laminated second support and the nanofiber web can be performed .

The step (2-1) is a step of laminating the second support and the nanofiber web. When the second support is implemented as a low-melting composite fiber, the nanofiber web and the second support are thermally fused through the calendering process. Binding can be carried out at the same time.

In addition, a separate hot melt powder or hot melt web may be further interposed in order to bind the second support and the nanofiber web. At this time, the applied heat may be 60 ~ 190 ℃, the pressure may be applied at 0.1 ~ 10kgf / ㎠, but is not limited thereto. However, components such as hot melt powder, which are added separately for binding, generate hum or are melted in the laminating process between supports and between supports and nanofibers to close pores frequently, so that the flow rate of the first designed filter media is achieved. may not be able to In addition, it is preferable to bind the second support and the nanofiber web without including it because it can be dissolved in the water treatment process and cause negative environmental problems.

Next, the first support may be disposed on both sides of the laminated second support and the nanofiber web. In this case, the step of laminating the laminated second support and the nanofiber web and applying any one or more of heat and pressure may be performed including the step of fusion bonding the first support and the second support.

A specific method of applying heat and/or pressure in the above step may adopt a known method, and a conventional calendering process may be used as an example, non-limiting example, and the temperature of the heat applied at this time is 70 to 190 ° C. can In addition, when performing the calendering process, it may be divided into several divisions and performed a plurality of times, for example, the second calendering may be performed after the first calendering. In this case, the degree of heat and/or pressure applied in each calendering process may be the same or different. Through the step (2-1), bonding can occur between the second support and the first support through thermal fusion, and there is an advantage that a separate adhesive or adhesive layer can be omitted.

Next, the present invention includes a filter unit implemented by including the filter media manufactured through the above-described manufacturing method.

As shown in FIG. 7A , the filter media 1000 may be implemented as a plate-type filter unit 2000 . Specifically, the plate-type filter unit 2000 includes a filter medium 1000 and a support frame 1100 for supporting the edge of the filter medium 1000, and a filter medium is provided in any one area of the support frame 1100. A suction port 1110 that can gradient the pressure difference between the outside and the inside of 1000 may be provided. In addition, in the support frame 1100, the filtrate filtered from the nanofiber webs 101 and 102 can flow out to the outside through the support 200 on which the second support/first support inside the filter medium 1000 is stacked. A flow path may be formed.

Specifically, in the filter unit 2000 as shown in FIG. 7A , when a high pressure suction force is applied through the suction port 1110, the filtrate P disposed outside the filter medium 1000 as shown in FIG. 7B is the filter medium 1000 ), and the filtrate (Q1) filtered through the nanofiber webs 101 and 102 flows along the flow path formed through the support 200 in which the second support / first support is stacked, and then the outer frame 1100. It is introduced into the flow path E provided in the , and the introduced filtrate Q2 may be discharged to the outside through the suction port 1110 .

In addition, the plate-type filter unit 2000 as shown in FIG. 7A may implement a filter module in which a plurality of filter modules are provided in one outer case with a predetermined interval therebetween, and such filter modules are stacked/blocked in plurality to form a large size. It is also possible to constitute a water treatment device.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention can add components within the scope of the same spirit. , changes, deletions, additions, etc. may easily suggest other embodiments, but this will also fall within the scope of the present invention.

101,102,111,112: nanofiber web 111a, 112a: nanofiber
121,122: second support 130: first support
1000: filter media 2000,2000': filter unit

Claims (22)

a porous first support;
a nanofiber web having a three-dimensional network structure disposed on one surface of the first support and formed of nanofibers in which a coating layer including a functional material surrounds the outer surface; and a porous second support interposed between the first support and the nanofiber web.
The nanofiber web is divided into first to third areas in the thickness direction from the surface in contact with the first support, and the first to third areas have values of Equations 1 to 3 of 0.98 to 1.02, respectively. ego,
The basis weight of the first support is 250 ~ 800 g / ㎡, and the basis weight of the second support is 35 ~ 80 g / ㎡,
The thickness of the first support is 90% or more of the total thickness of the filter media:
[Equation 1]

[Equation 2]

[Equation 3]

The method of claim 1,
The nanofiber web includes a plurality of pores formed by the intersection of nanofibers,
In the first to third regions, the values of Equations 4 to 6 are 0.98 to 1.02, respectively.
[Equation 4]

[Equation 5]

[Equation 6]

The method of claim 1,
The nanofiber includes a first polymer compound that is a hydrophobic polymer compound, and the coating layer includes a second polymer compound that is a hydrophilic polymer compound. The method of claim 1,
In the nanofiber web, a second spinning solution containing a fiber-forming polymer compound is electrospun through an inner tube of a spinning nozzle including an inner tube, an outer tube, and an outermost tube, and a functional material is provided through the outer tube. A filter medium formed by spraying air through the outermost tube, in which the first spinning solution is electrospun. A filter medium according to any one of claims 1 to 4; and
a support frame having a flow path through which the filtrate filtered from the filter medium flows out to the outside, and supporting an edge of the filter medium; A flat filter unit comprising a. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

Images