KR101866344B1 - Nano fiber filter and method of manufacturing the same - Google Patents

Abstract

The present invention relates to a method of manufacturing a nanofiber filter, and more particularly, to a method of fabricating a nanofiber filter using bottom-up electrospinning, which comprises the steps of: forming a bottom-up electrospinning unit The present invention relates to a method of manufacturing a nanofiber filter having different weights of nanofibers in the width direction (CD), in which a nozzle block is designed to have 2, 3 or 9 parts in the width direction (CD) To a nanofiber filter having different basis weights of nanofibers in an adjustable width direction (CD), and a method of manufacturing the same.

Description

TECHNICAL FIELD The present invention relates to a nanofiber filter and a method for manufacturing the nanofiber filter.

More particularly, the present invention relates to a method of manufacturing a nanofiber filter having different basis weights in the width direction (CD) and a nanofiber filter manufactured thereby

Generally, a nanofiber refers to a microfiber having a diameter of only a few tens to a few hundred nanometers, and is produced by an electric field. That is, nanofibers generate electrical repulsive force inside the polymer material by applying a high voltage electric field to the polymer material, which is the raw material, and the nanofibers are manufactured and produced by breaking the molecules into a nano-sized yarn shape.

At this time, as the electric field becomes stronger, the polymer material as the raw material is finely torn, so that a nanofiber having a thinning of 10 to 1000 nm can be obtained.

In the conventional technology for spinning nanofibers, since it is limited to a small-scale working line focused on a laboratory, there is a demand for a technique of spinning nanofibers by dividing a spinning zone and using a unit concept.

On the other hand, in the conventional electrospinning device, a spinning solution is electrospun on one surface of a substrate supplied from the outside, and a nanofiber filter is laminated to produce nanofibers. That is, the conventional electrospinning device comprises a bottom-up or bottom-down electrospinning device, and electrospinning the spinning solution only on the lower surface or the upper surface of the substrate supplied into the electrospinning device to form a nanofiber filter.

As described above, since the electrospinning device is composed of the bottom-up electrospinning device or the top-down electrospinning device, the spinning solution is electrospun on the bottom surface or the top surface of the substrate supplied from the outside and transported in a predetermined direction, can do.

As shown in FIG. 1, the top-down electrospinning device of the bottom-up or top-down electrospinning device includes a spinning solution main tank 120 filled with a polymer spinning solution and a polymer spinning solution filled in the spinning solution main tank 120 A nozzle block 111 for discharging the polymer solution in the spinning liquid main tank and having a plurality of nozzles 111a arranged in a pin shape and a nozzle block 111a And a voltage generator 114 for generating a high voltage in the collector 113. The collector 113 is disposed at a predetermined distance from the nozzle 111a in order to collect the polymer spinning solution injected from the collector 113, Units 110 and 110 '.

In the method of manufacturing the nanofiber filter through the electrospinning device 100, the polymer spinning solution filled in the spinning solution main tank 120 is continuously and quantitatively supplied to the nozzle block 111 to which a high voltage is applied through the metering pump The polymer spinning solution supplied to the nozzle block 111 is irradiated onto the substrate 113 to be transported in the electrospinning device 100 through the nozzle 111a on the collector 113 with a high voltage applied thereto, So that a nanofiber filter is laminated.

At this time, in the electrospinning apparatus 100, the substrate 115 is conveyed by the conveyance belt 116a rotated between the conveyance rollers 116b.

When the nanofiber filter manufactured by electrospinning a polymer spinning solution through the electrospinning device as described above is used as a filter material used in an industrial field, the basis weight of the entire nanofiber filter used as the filter material must be constant and uniform In the case of a filter used in a gas turbine of a thermal power plant, it is possible to manufacture and sell products satisfying the standard specifications. Depending on the direction of air inflow, the position of the inflow portion of the air, the direction of the air portion of the air, In some cases, the basis weight of the nanofiber filter constituting the filter material does not need to be constant. On the other hand, in the filter portion in which air filtration is active, the basis weight of the nanofiber filter should be controlled to be small in order to increase the air filtering efficiency. Since the air filter does not have a large air flow rate, the basis weight of the nanofiber filter There is a need for a design that is more durable than the air filtration side.

Thus, the basis weight of the nanofiber filter is required to be a nanofiber filter material having different basis weights on the same nanofiber filter depending on the positions of the air inlet and outlet.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a nanofiber filter having a different basis weight in the width direction (CD) in the planar direction of the nanofiber filter layer, And a method thereof.

In order to solve the above problems,

A substrate;

At least one nanofiber layer laminated on the substrate by electrospinning;

And a bonding layer formed between the substrate, the nanofiber layer and the nanofiber layer, the method comprising:

Wherein the nanofiber layer has a basis weight different from that of the nanofiber in the width direction,

Wherein the adhesive layer is formed by electrospinning a low-melting-point polymer solution, and provides a method for manufacturing a nanofiber filter.

The present invention can improve the durability and the productivity of nanofiber production by providing a nanofiber filter having different basis weights in the width direction.

1 is a side view schematically showing a nanofiber filter electrospinning device,
2 is a plan view schematically showing a nozzle body arranged in a nozzle block of a nanofiber filter electrospinning apparatus according to the present invention,
3 is a perspective view schematically showing a nozzle body arranged in a nozzle block of a nanofiber filter electrospinning apparatus according to the present invention,
4 is a side view schematically showing a nozzle body arranged in a nozzle block of a nanofiber filter electrospinning apparatus according to the present invention,
FIGS. 5 to 6 are diagrams showing an operation process in which the polymer spinning solution is electrospun on the same plane of the substrate through the nozzles of each nozzle tube of the nanofiber filter electrospinning apparatus according to the present invention (in FIG. 5, A nozzle indicated by a broken line in Fig. 6 is located at a lower portion of the substrate); Fig.
Figures 7 to 9 are plan views of a nanofiber filter in the width direction (CD) produced by the present invention.

An electrospinning device for manufacturing and producing nanofibers includes a spinning liquid main tank filled with spinning solution, a metering pump for supplying a fixed amount of spinning solution, a nozzle block having a plurality of nozzles for discharging spinning solution, And a voltage generating device for generating a voltage and a collector for accumulating the fibers that are positioned at the lower end of the nozzle and emit radiation.

The electrospinning device having the above-described structure includes a spinning liquid main tank filled with a spinning solution, a metering pump for supplying a fixed amount of the polymer spinning solution filled in the spinning solution main tank, and a polymer spinning solution in the spinning solution main tank A nozzle block having a plurality of nozzles arranged in a pin shape and arranged to discharge the polymer solution, and a collector disposed at an upper end of the nozzle and spaced apart from the nozzle by a predetermined distance in order to accumulate the polymer solution, And a unit including the apparatus.

Here, the electrospinning device is divided into a bottom-up electrospinning device, a top-down electrospinning device, and a horizontal electrospinning device depending on the direction on the collector. That is, the electrospinning device has a configuration in which the collector is located at the upper end of the nozzle, and a bottom-up electrospinning device capable of manufacturing a uniform and relatively thin nanofiber filter, a collector is disposed at the lower end of the nozzle, A top-down electrospinning device capable of producing a relatively thick nanofiber filter and capable of increasing the production amount of nanofibers per unit time, and a horizontal electrospinning device having a collector and nozzles arranged in a horizontal direction.

The bottom-up electrospinning device has a configuration in which a spinning solution is injected through a nozzle of an upward nozzle block, and a spinning solution to be injected is deposited on a lower surface of the support to form a nanofiber filter.

According to the above-described configuration, the elongated sheet in which the spinning solution is injected through one of the nozzles of the bottom-up electrospinning device so as to laminate the nanofiber filters is conveyed to the inside of the other unit, A nanofiber filter is manufactured by repeatedly performing the above-described processes such as spraying a spinning solution through a nozzle onto a long sheet to form a laminate of nanofibers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the scope of the present invention, but is merely an example, and various modifications can be made without departing from the technical gist of the present invention.

The nanofiber generally means a fiber having an average diameter of 50 to 1000 nm or less and can be manufactured using an electrospinning device.

The electrospinning apparatus includes a power supply, a spinning nozzle, a collector, and the like. The power supply forms an electric field of high voltage between the nozzle and the collector. The spinning nozzle supplies spinning solution to the spinning space. The collector concentrates the electrospun nanofibers. The filaments formed in the spinning space of the electrospinning device may have various average diameters depending on spinning conditions, and may be nanofibers having an average diameter of 50 to 1000 nm.

FIG. 2 is a plan view schematically showing a nozzle body arranged in a nozzle block of a nanofiber filter electrospinning apparatus according to the present invention, and FIG. 3 is a cross-sectional view of a nozzle block arranged in the nozzle block of the nanofiber filter electrospinning apparatus according to the present invention. 4 is a side view schematically showing a nozzle body arranged in a nozzle block of a nanofiber filter electrospinning apparatus according to the present invention, and FIGS. 5 to 6 show a nanofiber filter electrospinning apparatus according to the present invention, FIG. 2 is a plan view schematically showing an operation process in which a polymer spinning solution is electrospun on the same plane of a substrate through a nozzle of each nozzle tube of the spinning device. FIG.

1, the electrospinning apparatus 100 according to the present invention comprises a bottom-up electrospinning apparatus, in which a low-melting polymer unit 110 and a spinning solution unit 110 ' Lt; / RTI > In one embodiment of the present invention, the electrospinning device 100 is a bottom-up electrospinning device, but it may also be a top-down electrospinning device.

Here, a low melting point polymer solution for forming an adhesive layer is electrospinned to the low melting point polymer unit 110, and a polymer solution for forming a nanofiber layer is electrospun in the spinning solution unit 110 '.

The low melting point polymer used in the adhesive layer is selected from low melting point polyvinylidene fluoride, low melting point polyurethane, and low melting point polyester.

In the low melting point polymer solution, the low melting point polyurethane is a low degree of polymerization polyurethane having a softening temperature of 80-100 ° C.

The low melting point polyester is preferably terephthalic acid, isophthalic acid or a mixture thereof. It is also possible to add ethylene glycol as a diol component to further lower the melting point.

The low melting point polyvinylidene fluoride is a low melting point polyvinylidene fluoride having a weight average molecular weight of 5,000 and a melting point of 80 to 160 ° C.

It is needless to say that the low melting point polyurethane, the low melting point polyester and the low melting point polyvinylidene fluoride may be used singly or in combination of two or more.

The low melting point polymer unit 110 and the spinning solution unit 110 'are connected to the main tank 120, respectively.

(Not shown) for supplying the spinning liquid filled in the spinning liquid main tank 120 in a fixed amount and a nozzle 111a having a pin shape for discharging the polymer spinning solution in the spinning liquid main tank 120, A nozzle block 111 having a plurality of nozzle tubes 112 arranged in the width direction of the substrate 115 and a nozzle 111a for collecting the polymer solution for spraying from the nozzle 111a And a voltage generator 114 for generating a high voltage to the collector 113. The collector 113 is connected to the collector 113,

In the nanofiber filter electrospinning device 1 as described above, the polymer spinning solution filled in the spinning liquid main tank 120 is continuously and quantitatively supplied to the nozzle block 111 to which a high voltage is applied through the metering pump, The polymer spinning solution supplied to the nozzle block 111 is radiated and focused onto the substrate 113 transferred in the electrospinning device through the nozzle 111a on the collector 113 with a high voltage applied thereto, Respectively.

At least one or more units 110 and 110 'provided in the nanofiber filter electrospinning device 1 are sequentially spaced apart from each other by a predetermined distance and the polymer solution is supplied through the units 110 and 110' Spinning to produce a nanofiber filter.

The nozzle block 111 of the electrospinning apparatus 100 includes a plurality of nozzle tubes 112 arranged in the width direction thereof and a spinning liquid main tank for supplying a polymer spinning solution to the nozzle tubes 112 120 are connected to each other.

The nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, and 112i, which are linearly formed on the upper surface of the nozzle block 111 and have a plurality of nozzles 111a linearly, A plurality of nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i are arranged in the width direction of the substrate 115 in the width direction of the substrate 115, And the polymer spinning solution filled in the spinning solution main tank 120 is supplied.

Here, the nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, and 112i are connected to the spinning solution main tank 120 through a solution supply tube 121, A plurality of nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i and a spinning liquid main tank 120 are branched.

At this time, the solution supply pipe 121, which is communicated with the nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i in the spinning solution main tank 120, , And the supply amount adjusting means is composed of a supply valve (122).

A supply valve 122 is provided in the solution supply pipe 121 which is communicated to each nozzle body 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i in the spinning liquid main tank 120 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i in the spinning liquid main tank 120 by the supply valves 122, And controlled on-off systems.

That is, when the polymer spinning solution is supplied to the nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i from the spinning solution main tank 120 through the solution supply tube 121, By the opening and closing of the supply valve 122 provided in the solution supply pipe 121 for supplying the main tank 120 and the nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, The nozzle tubes 112b, 112d, 112f, 112g, 112h, 112i at specific positions among the nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i arranged in the nozzle block 111 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i, 112f, 112g, 112h, 112i, 112f, 112h, 112h, 112h, The supply of the polymer solution is controlled and controlled.

For this purpose, the supply valve 122 is preferably controllably connected to a control unit (not shown). Preferably, the opening and closing of the supply valve 122 is automatically controlled by the control unit. However, It is also possible that the opening and closing of the supply valve 122 is manually controlled.

112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i in the spinning liquid main tank 120. However, The supply amount adjusting means may be composed of various other structures and means, but the present invention is not limited thereto.

The solution supply pipe 121 is connected to the spinning solution main tank 120 and the nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h and 112i, A supply valve 122 is provided at each of the nozzles 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i in the spinning liquid main tank 120 to supply a plurality of 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i arranged in the nozzle block 111 by opening the specific supply valve 122 of the supply valve 122, The nozzle tubular body 112a (112a, 112b, 112d, 112f, 112g, 112h, 112i) at the specific position among the nozzle tubular bodies provided in the nozzle block 111 by supplying the polymer solution, , 112c, and 112e of the spinning liquid main tank 120 are blocked by the opening and closing of the supply valve 122, The supply of the polymer spinning solution to be supplied to the (112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i) is adjusted and controlled.

The polymer spinning solution supplied to the nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i through the solution supply tube 121 in the spinning solution main tank 120 flows through the solution supply tube 121, 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i through a nozzle supply pipe 125 which is connected to the nozzles 121a.

That is, the nozzles 111a provided in the solution supply pipe 121 and the nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h and 112i are provided as nozzle supply pipes 125, The supply pipe 125 is branched so as to correspond to the number of the nozzles 111a.

Here, the nozzle supply pipe 125 is provided with a dose adjusting means (not shown), and the dose adjusting means comprises a nozzle valve 126.

The supply of the polymer solution to be supplied to each nozzle 111a from the nozzle supply pipe 125 is controlled individually by the nozzle valve 126 by the opening and closing of the nozzle valve 126, Preferably, the nozzle valve 126 is controllably connected to a control unit (not shown), and the opening and closing of the nozzle valve 126 is automatically controlled by the control unit. However, It is also possible that the opening and closing of the nozzle valve 126 are manually controlled.

In an embodiment of the present invention, if the amount of the spinning solution of the polymer spinning solution is easily controlled and controlled after being supplied to the nozzle 111a from the nozzle tube, the spinning amount adjusting means is composed of the nozzle valve 126, But the present invention is not limited thereto.

According to the structure described above, the solution supply pipe 121 and the nozzles 111a are connected to each other, and the nozzle valve 126 is provided in the nozzle supply pipe 125, Of the plurality of nozzle valves 126 when supplying the polymer spinning solution to the respective nozzles 111a through the respective nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, The polymer spinning solution is selectively discharged only from the nozzles 111a at specific positions among the nozzles 111a provided in the nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, Or a specific nozzle valve 126 is closed so that the nozzles 111a provided in the nozzle tubes 112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, The nozzle tubular body 112a, the tubular body 112a, the tubular body 112a, and the nozzle body 112b are separated from the spinning liquid main tank 120 by the nozzle valve 126, 112b, 112c, 112d, 112e, 112f, 112g, 112h, and 112i, the supply of the polymer spinning solution supplied to each nozzle 111a is individually controlled and controlled.

In an embodiment of the present invention, the solution supply pipe 121 is provided with a supply valve 122 so that the nozzle tubes 112a, 112b, 112c, 112d and 112e of the nozzle block 111 in the spinning liquid main tank 120 112b, 112c, 112d, 112f, 112g, 112h, and 112i, and a nozzle valve 126 is provided in the nozzle supply pipe 125 to adjust the supply amount of the polymer solution, 112b, 112c, 112d, 112e, 112f, 112c, 112d, 112e, 112f, 112f, 112g, 112h, 112i to regulate and control the radiation amount of the polymer spinning solution which is radiated through each nozzle 111a, 112a, 112b, 112g, 112h, and 112i, a nanofiber filter having different weights in the width direction of the base material 115 is laminated on the nozzle block 111 by a polymer spinning solution electrospunneled from each nozzle 111a of the nozzle block 111. However, After the nozzles 111a are arranged, the nozzles 111a are directly controlled and controlled individually The nanofiber filter having different basis weights may be laminated in the width direction of the base material 115 by controlling and controlling the amount of the spinning solution of the polymer to be electrospun through each of the nozzles 111a.

The MD direction used in the present invention means a machine direction, and means a longitudinal direction corresponding to the progress direction in the case of continuously producing fibers such as a film or a nonwoven fabric, and the CD direction means a perpendicular direction to the MD direction as a cross direction . MD is the machine direction / longitudinal direction, and CD is the width direction / transverse direction.

Basis Weight or Grammage is defined as the mass per unit area, that is, the preferred unit, grams per square meter (g / m 2).

An on-off system based on an independent nozzle block can control the basis weight of the polymer solution stacked on the substrate differently. Typically, the basis weight of the nanofiber filter layer can be appropriately selected depending on the application, but the basis weight is in the range of 0.1 to 0.5 g / m 2.

Hereinafter, the polymer used in the present invention will be described. Polymers of the present invention and polyvinylidene fluoride, polyurethane and nylon are preferable for the polymer.

The polymer may be at least one selected from the group consisting of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, or a composite composition thereof, a polyurethane, a polyamide, a polyimide, a polyamideimide, a poly (meta-phenylene isophthalate Amide), meta-aramid, polyethylene chlorotrifluoroethylene, polychlorotrifluoroethylene, polymethylmethacrylate, polyacrylonitrile, polyvinylidene chloride, polyvinylidene chloride-acrylonitrile copolymer, polyacrylic Amide, and the like.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to examples. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

The physical property values in the examples were measured by the following methods.

Basis weight [g / m ² ]

Six specimens of 200 mm (MD) x 50 mm (CD) were taken from the nanofiber layer. On the other hand, the sampling sites were randomly selected from each of the different weights by an on-off control system. Subsequently, each of the test specimens thus obtained was measured for weight (g) by using a top dish electronic balance. The average mass of each specimen was determined. (G) per 1 m < ² > from the average value obtained, and the first digit of the decimal point was rounded off to obtain the basis weight of the nanofiber layer sample.

Example 1

Melting polymeric solution 110 having a softening temperature of 80-100 DEG C was dissolved in a solvent of DMAc (N, N-dimethylaceticamide) in an amount of 15% by weight to prepare a low melting point polymer solution. Lt; / RTI > In addition, polyvinylidene fluoride having a weight average molecular weight of 50,000 was dissolved in dimethylacetamide (N, N-dimethylacetamide, DMAc) to prepare each spinning solution, and this was injected into the main tank connected to the spinning solution unit 110 ' Respectively.

The adhesive layer having a basis weight of 0.1 g / m < ² > was formed on the cellulose substrate by the electrospinning of the distance between the electrodes and the collector at 40 cm, the application voltage 25 kV, and 70 DEG C in the low melting point polymer unit 110, The distance between the electrode and the collector is 40 cm, the applied voltage is 20 kV, and 70 ° C. In one direction in the width direction (CD), the basis weight of the polyvinylidene fluoride nanofiber is 0.2 g / m ² and the remaining 1 m is the basis weight A nanofiber filter having a CD width of 2 m with a density of 0.5 g / m ² was prepared.

Example 2

A polyurethane solution having a weight average molecular weight of 157,000 is dissolved in dimethylformamide (DMF) to prepare a polyurethane solution. The polyurethane solution was fed into each of the spinning liquid main tanks and the applied voltage was applied to the nozzle block including the on-off system designed to have three nozzle blocks separated in one direction in the width direction (CD) at 20 kV, 3 g / m < ^{2 &} gt ;. Electrical intermediate portion 1m of radiation onto a collector in the width direction (CD) is a polyester having a weight of 0.5 / m ² polyurethane nanofibers, and the other edge is 50cm with a basis weight of 0.2g / m ² of CD width of 2m polyurethane nanofiber To form a polyurethane nanofiber filter. At this time, bottom-up electrospinning was performed under the condition that the distance between the electrode and the collector was 40 cm and the temperature was 22 ° C.

Example 3

A polyurethane solution is prepared by dissolving a polyurethane having a weight average molecular weight of 157,000 in dimethylformamide (DMF). The polyurethane solution was put into the main tank of the spinning solution and the applied voltage was applied to the nozzle block including the on-off system designed to have nine nozzle blocks separated in one direction in the width direction (CD) at 20 kV, g / m < ^{2 &} gt ;. Electricity is radiated on a cellulose base material having a basis weight of the polyurethane nanofiber alternately in the width direction (CD) 0.2g / m ² and the basis weight of the remainder of the 2m 0.5g / m ² of CD width polyurethane nanofibers To prepare a polyurethane nanofiber filter. At this time, bottom-up electrospinning was performed under the condition that the distance between the electrode and the collector was 40 cm and the temperature was 22 ° C.

100: electrospinning device, 110, 110 ': unit,
111: nozzle block, 111a: nozzle,
112: nozzle body,
112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h, 112i:
113: collector, 114: voltage generator,
115: substrate,
115a, 115b and 115c: nanofiber filters,
116a: conveying belt, 116b: conveying roller,
120: spinning liquid main tank, 121: solution supply pipe,
122: supply valve, 125: nozzle supply pipe,
126: Nozzle valve.
a, b, c, d, e, f: different basis weights of nanofibers

Claims (4)

A substrate;
At least one nanofiber layer laminated on the substrate by electrospinning;
And a bonding layer formed between the substrate, the nanofiber layer and the nanofiber layer, the method comprising:
Wherein the nanofiber layer has different basis weights of the nanofibers in the width direction (CD)
The adhesive layer is formed by electrospinning a low melting point polymer solution selected from low melting point polyvinylidene fluoride, low melting point polyurethane and low melting point polyester,
The basis weight of the nanofibers is characterized in that a plurality of nozzle tubes are operated by an on-off system,
Wherein the basis weight is in the range of 0.1 to 0.5 g / m < ² > and the basis weight of the nanofibers is different in the width direction (CD). The method according to claim 1,
Wherein the on-off system is designed such that the basis weight is alternately changed in the width direction (CD) in which nanofibers are integrated, wherein the basis weight of the nanofibers is different in the width direction (CD). delete A nanofiber filter produced by the method of claim 1.

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