KR20200018973A - Filter media and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a filter medium, which comprises: a plurality of bending parts; first and second filtering members; an adhesive; and a plurality of elastic filaments. The filter medium of the present invention can be contracted in a machine direction by a contractive force of the elastic filaments. The bending parts are alternately connected in the machine direction, and separately extend in a transverse direction perpendicular to the machine direction. The first and second filtering members separately form a part and a remaining part of the bending parts in the machine direction and the transverse direction. The adhesive is applied to at least one of the first and second filtering members. The elastic filaments are coupled to one of the first and second filtering members between the first and second filtering members by the adhesive. Each of the elastic filaments is oriented in the machine direction, and is separated in the transverse direction from each other. A plurality of filaments are contracted to a shape corresponding to a bent shape of the bending parts to maintain the bent shape.

Description

Filter media and its manufacturing method {FILTER MEDIA AND MANUFACTURING METHOD THEREOF}

The present disclosure relates to filter media and methods of making the filter media.

Industrial or domestic air conditioners or vehicle air filters use filter media for filtering contaminants in the air. In order to improve the trapping ability of the filter medium and the differential pressure (difference in pressure applied to both ends through which air is permeated), a technique of imparting a bending shape to the filter medium is known. For example, Korean Patent Laid-Open Publication No. 10-2004-0053088 proposes to form a bent portion of a triangular waveform having peaks and valleys by pleating in a nonwoven filter media. Filter media with bends can have improved trapping capacity and reduced differential pressure due to the extended surface area.

In general, a bending process is performed on a filter medium laminated through a lamination process to produce a filter medium having a bent portion. The bending process is performed on the filter media in a separate process from the lamination process, and a plurality of bent portions are formed on the filter media by bending the laminated filter media with a bending machine. Further, in order to maintain the bent shape of the filter media, the filter media is made from a high stiffness nonwoven fabric.

In order to maintain the bent shape of the filter media and to maintain the rigidity of the filter media in which the bent portion is formed, the filter media in which the bent portion is formed cannot be wound in a roll form. Accordingly, the filter medium which has been subjected to the bending process must be produced as a filter medium of the finished product immediately after the bending process, and for this purpose, manufacturers of the filter medium must have a bending process facility. Such a bending process and a bending process facility complicate the manufacturing process of a filter medium, and raise manufacturing cost.

In the prior art filter media having bends, due to limitations in the bending machine and the bending process, the shape and dimensions of the bends are inevitably limited to constant shapes and constant dimensions. That is, the bent portion having a constant shape and dimension is formed entirely on the filter media. For this reason, the size of the housing or frame of the filter device to which the filter media is to be applied is inevitably limited.

In order that the filter media can be applied to various filter devices, the number of bends and the dimensions of the bends need to be designed differently according to various applications of the filter device. However, the filter medium of the prior art in which the bent portion is formed in a constant dimension and shape by the bending machine cannot be easily applied to various applications of the filter device.

In addition, the filter medium of the prior art having the above-described bent portion and rigid to maintain the bent shape, due to the stiffness of the filter medium itself and the shape of the bent portion may be applied as a filter media of an industrial air conditioner, It cannot be applied as a filter medium. In other words, the filter medium having the aforementioned bent portion can be applied only to a limited filter device due to its structure.

Republic of Korea Patent Publication No. 10-2004-0053088

One embodiment of the present disclosure provides a filter medium in which a fine pleat structure is formed without a bending process. One embodiment of the present disclosure provides a filter medium having improved trapping ability and differential pressure performance and having elasticity. One embodiment of the present disclosure provides a method of manufacturing a filter medium having a fine pleat structure is formed without a bending process, has improved trapping ability and differential pressure performance, and retains elasticity.

One aspect of embodiments of the present disclosure relates to filter media. The filter media of one embodiment includes a plurality of bends, first and second filtration members, an adhesive, and a plurality of elastic filaments, and are retractable in the machine direction by the contracting force of the elastic filaments. The plurality of bends alternate alternately in the machine direction, each extending in the transverse direction orthogonal to the machine direction. The first and second filtration members form part of the plurality of bends and the remaining part respectively in the machine direction and in the transverse direction. The adhesive is applied to at least one of the first and second filtration members. The plurality of elastic filaments are bonded to at least one of the first and second filtration members by an adhesive between the first and second filtration members. Each of the plurality of elastic filaments is oriented in the machine direction and spaced apart in the transverse direction. The plurality of filaments are contracted to a shape corresponding to the curved shape of the plurality of curved portions to maintain the curved shape.

In one embodiment, the plurality of elastic filaments extend continuously in the machine direction.

In one embodiment, the plurality of elastic filaments have a diameter of 0.5 mm to 1.0 mm. In addition, each of the plurality of elastic filaments is spaced at intervals of 2.5 mm to 10.0 mm in the transverse direction.

In one embodiment, the plurality of elastic filaments are stretchable in the machine direction at an elongation of 100% to 300%.

In one embodiment, the material comprising the plurality of elastic filaments comprises any one of a styrene block copolymer, a styrene-ethylene / butylene-styrene block copolymer and an olefin block copolymer.

In one embodiment, the plurality of bends have different widths in the machine direction.

In one embodiment, each of the plurality of bends has an arc cross-sectional shape and the arc shapes are curved with different curvatures.

In one embodiment, the plurality of bends are connected in the machine direction such that neighboring bends partially overlap in the machine direction.

In one embodiment, the filter media may comprise 5 to 15 bends per cm.

Another aspect of embodiments of the present disclosure relates to a method of making a filter media. According to one embodiment, there is provided a method of manufacturing a filter media, the method comprising: transferring at least one first and second filtration members coated with an adhesive to a pair of lamination rolls, and a transverse direction continuous in the machine direction and perpendicular to the machine direction Extruding a plurality of filaments spaced apart from each other; stretching the extruded plurality of filaments in a machine direction while cooling the extruded plurality of filaments by a cooling roll; and extending the plurality of stretched filaments toward a lamination roll. Conveying between, laminating the plurality of filaments stretched with the first and second filtration members by the lamination rolls, and contracting forces of the stretched plurality of filaments in the machine direction. Contracting to form a plurality of bends alternately connected in the machine direction and each extending in the transverse direction.

In one embodiment, the cooling roll comprises a first cooling roll and a second cooling roll arranged vertically above the lamination roll and rotating in different directions. The plurality of filaments are in contact with the first cooling roll and then with the second cooling roll. In the stretching of the plurality of filaments, the conveying speed of the plurality of filaments conveyed by the second cooling roll is greater than the conveying speed of the plurality of filaments conveyed by the first cooling roll.

In one embodiment, in the step of conveying the plurality of filaments, the conveying speed of the plurality of filaments conveyed by the lamination roll is greater than the conveying speed of the plurality of filaments conveyed by the second cooling roll.

In one embodiment, stretching the plurality of filaments extends the plurality of filaments at an elongation of 300% to 450%.

In one embodiment, in the step of extruding the plurality of filaments, each of the plurality of filaments are spaced at intervals of 2.5 mm to 10.0 mm in the transverse direction.

In one embodiment, extruding the plurality of filaments is performed by extruding the filament raw material by an extruder. The filament raw material includes any one of a styrene block copolymer, a styrene-ethylene / butylene-styrene block copolymer, and an olefin block copolymer.

In one embodiment, in the step of transferring the first and second filtration members to the lamination roll, the adhesive is applied to at least one of the first and second filtration members by a slot die in a basis weight of 0.3 gsm to 2.0 gsm.

In an embodiment of the filter media and method of manufacturing the same, one of the first and second filtration members may comprise an unthroughened airthrough nonwoven or spunbond nonwoven with a basis weight of 10 gsm to 100 gsm, and the first and second The other of the two filtration members may comprise a meltblown nonwoven fabric having a basis weight of 10 gsm to 50 gsm.

In embodiments of the filter media and methods of making the same, the first and second filtration members may comprise a meltblown nonwoven fabric having an electrostatic treatment having a basis weight of 10 gsm to 50 gsm.

The filter media of the embodiment has a number of fine bends that are bent by elastic filaments. Since the elastic filaments embedded in the filter media form a number of fine bends, this eliminates the additional process performed separately from the lamination process to form the fine bends. The filter media of one embodiment having multiple fine bends can have improved filtration efficiency and improved differential pressure. Since many fine bends do not have a constant shape and a certain dimension, the filter media of one embodiment enables the manufacture of a filter device that can be applied to narrow spaces as well as to filter devices of various sizes. Since the many fine bends retain elasticity, the filter media of one embodiment can be easily applied to the housings of various filter devices. The filter media of one embodiment having multiple fine bends is stretchable and retractable in the machine direction and elastically recoverable in the vertical direction. Accordingly, the fabric including the filter media of the embodiment can be wound in a roll form, thereby realizing easy storage. The filter media of one embodiment having a number of fine bends can be used in the filter device of an industrial or domestic air conditioner or as a filter media of a wearable mask.

1 illustrates a photograph of a filter medium according to an embodiment.
2 is a partial perspective view illustrating a filter medium according to an embodiment.
3 is a cross-sectional view taken along the line 3-3 of FIG.
4 is a cross-sectional view taken along line 4-4 of FIG.
FIG. 5 shows side-by-side and stretched examples of filter media according to one embodiment.
6 is a block diagram illustrating steps of a method of manufacturing a filter medium according to an embodiment.
7 schematically illustrates a manufacturing apparatus that may be used to manufacture a filter media according to one embodiment.
8 schematically illustrates an example of adhesive application using a slot die.
9 is a graph showing the filtration efficiency in the filter media of the test example and the filter media of the comparative example according to an embodiment.
10 is a graph showing the differential pressure performance in the filter media of the test example and the filter media of the comparative example according to an embodiment
11 is a table showing the air permeability of the filter media of the test example and the filter media of the comparative example according to an embodiment.
12 is a graph showing filtration efficiency and differential pressure performance in the filter media of the test examples and the filter media of the various comparative examples according to an embodiment.
FIG. 13 is a graph illustrating filtration efficiency and differential pressure performance in filter media of test examples and filter media according to various comparative examples, according to an example. FIG.

Embodiments of the present disclosure are illustrated for the purpose of describing the technical spirit of the present disclosure. The scope of the claims according to the present disclosure is not limited to the embodiments set forth below or the detailed description of these embodiments.

All technical and scientific terms used in the present disclosure, unless defined otherwise, have the meanings that are commonly understood by one of ordinary skill in the art to which this disclosure belongs. All terms used in the present disclosure are selected for the purpose of more clearly describing the present disclosure, and are not selected to limit the scope of the rights according to the present disclosure.

As used in this disclosure, expressions such as "comprising", "including", "having", and the like, are open terms that imply the possibility of including other embodiments unless otherwise stated in the phrase or sentence in which the expression is included. It should be understood as (open-ended terms).

As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Expressions such as “first”, “second”, and the like used in the present disclosure are used to distinguish a plurality of components from each other, and do not limit the order or importance of the components.

In the present disclosure, when a component is referred to as being "connected" or "connected" to another component, the component may be directly connected to or connected to the other component, or new It is to be understood that the connection may be made or may be connected via other components.

The numerical values described in the present disclosure are not limited only to the numerical values described. Unless otherwise specified, such numerical values can be understood to mean the values stated and the equivalent ranges including the same. For example, a value of '2.5 mm' described in the present disclosure includes 'about 2.5 mm', and a value of '300%' described in the present disclosure may be understood to include 'about 300%'. .

As used in this disclosure, the direction indicators "upward" and "downward" are based on the orientation of the accompanying drawings. The direction indicator of the "machine direction" used in the present disclosure is based on the direction in which the material of the article is conveyed in the manufacturing machine at the time of manufacture of the article according to the present disclosure, and the "cross-machine direction" Means the direction orthogonal to the machine direction.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the accompanying drawings, the same or corresponding components are given the same reference numerals. In addition, in the following description of the embodiments, it may be omitted to repeatedly describe the same or corresponding components. However, even if the description of the component is omitted, it is not intended that such component is not included in any embodiment. In addition, embodiments of the disclosed manufacturing method may include some or all of the steps shown in the drawings. The steps shown in the drawing may be performed sequentially, or at least two or more steps in the steps shown in the drawing may be performed simultaneously, or one of the steps shown in the drawing may be performed in dependence on another step.

The embodiments described below and the examples shown in the accompanying drawings relate to filter media for filtering contaminants in air and methods of making such filter media. The filter media according to the embodiments can be used as a filtration member inside a filter device or as a filtration member of a mask. However, the example in which the filter medium according to the embodiments is applied is not limited to the above-described example.

A filter medium according to an embodiment is described with reference to the examples shown in FIGS. 1 to 5.

1 is a view showing a photograph of a filter medium according to an embodiment, and FIG. 2 is a perspective view illustrating a part of the filter medium according to an embodiment. 1 and 2, the filter media 100 has a finely pleated structure as a whole. This fine pleat structure provides an enlarged surface area for the air passing through the filter media 100 so that the filter media 100 has an improved capture capacity for contaminants. The fine pleat structure is realized by a number of bends 110 provided entirely in the filter media 100. That is, the filter media 100 includes a plurality of bends 110 as a whole.

The plurality of bends 110 are alternately connected in the longitudinal direction or the width direction of the filter media 100, or in the machine direction (MD). That is, the one bent part 110 and the other one bent part 110 adjacent thereto are positioned in opposite directions, and the one bent part 110 is connected in the opposite direction to the other bent part 110. Accordingly, when the filter medium 100 is viewed from the side, the plurality of bends 110 have a bent shape that is successively continued in an orientation in which a plurality of S-shapes are alternately opposite to each other. Each bend 110 extends in a cross-machine direction (CD) orthogonal to the machine direction MD of the filter media 100.

An elastic support element (eg, a plurality of elastic filaments described below) embedded in the filter media 100 forms a plurality of bends 110 and maintains the bent shape of the plurality of bends 110. The filter media 100 having a plurality of bends 110 may be stretched in the machine direction MD to resist the elastic force of the elastic support element and may be contracted in the machine direction MD by the contractive force of the elastic support element. have. The plurality of bends 110 may be formed in the filter media 100 without a separate machining process (eg, a pleating process) by the contracting action of the elastic support element. Since the bend 110 is formed in the filter media 100 without the above-described bending process, the filter media 100 of one embodiment excludes the bending process that is separate from the lamination process after the lamination process.

3 shows a cross-sectional shape taken along line 3-3 of FIG. 2, and FIG. 4 shows a cross-sectional shape taken along line 4-4 of FIG. 2. Reference is made to FIGS. 2 to 4 together for a detailed description of the filter media according to one embodiment.

The filter media 100 includes a first filtration member 120 and a second filtration member 130, and a plurality of elastic filaments 150 embedded therebetween, and the first and second filtration members 120, 130 and a laminated article of elastic filament 150.

The first and second filtration members 120 and 130 perform a filtration function. The first and second filtration members 120 and 130 form part of the plurality of bends 110 and the remaining part, respectively, in the machine direction MD and the transverse direction CD. As shown in FIG. 3, the first filtration member 120 may function as a filtration member on one side of the filter media 100 based on the elastic filament 150, and the second filtration member 130 may be elastic. The filament 150 may function as a filtration member on the other side of the filter media 100.

The first and second filtration members 120 and 130 comprise a nonwoven fabric. Nonwoven fabrics comprise an aggregate of microfibers in a network structure and have a large specific surface area and light weight. Nonwovens can improve filtration efficiency by complex capture mechanisms such as direct blocking of contaminants, inertia impacts, diffusion and gravity.

As one example, one of the first and second filtration members 120, 130 may comprise an air-through nonwoven or spunbond nonwoven having a basis weight of 10 gsm to 100 gsm. The other of the second filtration members 120 and 130 may include a melt-blown nonwoven fabric having a basis weight of 10 gsm to 50 gsm. In this example, the nonwoven can include polypropylene fibers, polyethylene fibers, or both. Also, the airthrough nonwoven or spunbond nonwoven may not be electrostatically treated and the meltblown nonwoven may be electrostatically treated. In this example, an air through nonwoven or spunbond nonwoven can be employed as the first filtration member 120 and disposed on the inflow side of the pollutant. The first filtration member 120 may function as a prefilter, exhibit surface rigidity, and collect contaminants larger than about 1 μm. The electrostatic meltblown nonwoven fabric may be employed as the second filtration member 130 and the main filter, and disposed behind the first filtration member 120 with respect to the inflow side of the contaminants. The electrostatic meltblown nonwoven can capture contaminants of about 0.3 μm in size. According to this example, since the first filtering member 120 of the air-through nonwoven fabric or the spunbond nonwoven fabric collects a relatively large contaminant, it is possible to maintain the capturing capability of the second filtering member 130 of the meltblown nonwoven fabric for a long time. have.

As another example, both the first and second filtration members 120 and 130 may comprise a meltblown nonwoven fabric having a basis weight of 10 gsm to 50 gsm and electrostatically treated. Accordingly, the filter media can have higher filtration performance.

The first filtration member 120 and the second filtration member 130 are joined to each other by an adhesive 140 disposed therebetween. As the adhesive 140, an adhesive capable of preventing the loss of performance of the filtration member by heat may be used. For example, a hot melt hot melt adhesive may be used as the adhesive 140. More specifically, as the adhesive 140, an olefinic adhesive having high creep resistance may be used.

As shown in FIGS. 3 and 4, the adhesive 140 may be applied to both mutually facing surfaces of the first filtration member 120 and the second filtration member 130. Alternatively, the adhesive 140 may be formed on the surface of the first filtration member 120 that faces the second filtration member 130 or on the surface of the second filtration member 130 that faces the first filtration member 120. Can be applied. The adhesive 140 may be applied to the surface of the first filtration member 120 or the surface of the second filtration member 130 by a slot die coating method or by a spraying method. For example, the coating amount of the adhesive 140 may be a basis weight of 0.3gsm to 2.0gsm. 3 and 4, although the adhesive 140 is shown in the form of a continuous layer to show the position of the adhesive 140, the adhesive 140 is formed in a non-contiguous shape so that the first and second filtration members ( It may be disposed between 120 and 130.

The plurality of elastic filaments 150 are embedded between the first filtration member 120 and the second filtration member 130. The plurality of elastic filaments 150 may be coupled to at least one of the first filtration member 120 and the second filtration member 130 by the adhesive 140. When the adhesive 140 is applied to the first and second filtration members 120 and 130, the plurality of elastic filaments 150 may be coupled to both the first filtration member 120 and the second filtration member 130. have.

The elastic filament 150 coupled to the first filtration member 120 or the second filtration member 130 causes the first filtration member 120 and the second filtration member 130 to shrink them in the machine direction MD. By applying a contractive force, a plurality of bends 110 are generated in the filter media 100. The filter media 100 may be stretched in the machine direction MD in response to the contraction force of the elastic filament 150. When the filter media 100 is stretched in the machine direction MD, the curved shape of the bent part 110 may be changed into a flat shape. In addition, the stretched filter media 100 may be shrunk in the machine direction MD by the contracting force of the elastic filament 150. When the filter media 100 is contracted in the machine direction MD, the flat bent part 110 may be bent in a bent shape before being stretched due to the bent shape of the contracted elastic filament 150. . For example, if the shrinkage force is measured from the specimen of the filter media having a width of 3 inches, the filter media 100 may have a contraction force of 100 gf to 200 gf at 50% elongation, and 200 gf to 400 gf at 100% elongation. May have contractile force.

As an example, the plurality of elastic filaments 150 may have a diameter of 0.5 mm to 1.0 mm. This diameter may be appropriately determined in consideration of the shrinkage of the first and second filtration members 120 and 130 and the thickness of the filter media 100.

As one example, as the material for forming the elastic filament 150, styrene block copolymer (SBC), styrene-ethylene / butylene-styrene block copolymer (SEBS) or olefin block copolymer (OBC) may be used, The material of the elastic filament 150 is not limited to this. As a material for forming the elastic filament 150, an elastic copolymer that can be elastically recovered and has an elongation of about 450% can be used.

Each of the plurality of elastic filaments 150 is oriented in the machine direction MD between the first and second filtration members 120, 130. In addition, each of the plurality of elastic filaments 150 may extend continuously in the machine direction MD between the first and second filtration members 120, 130. In addition, in the filter media 100, the length of the plurality of elastic filaments 150 may be the same as the length in the machine direction MD of the first filtration member 120 or the second filtration member 130. .

Each of the plurality of elastic filaments 150 is spaced apart in the lateral direction CD. Referring to FIG. 4, each of the plurality of elastic filaments 150 may be spaced apart at an interval FS in the lateral direction CD, and the interval FS may be 2.5 mm to 10.0 mm. The distance FS may be determined between 2.5 mm and 10.0 mm in consideration of physical properties of the elastic filament 150 and smooth shrinkage of the first and second filtration members 120 and 130. If the spacing FS is smaller than 2.5 mm, the manufacturing cost can be increased due to the dense filaments and too strong shrinkage force can be given to the filter medium 100. When the interval FS exceeds 10.0 mm, the contraction of the first and second filtration members 120 and 130 may not be smoothly performed. As an example, the spacing FS may be 2.8 mm or 3.6 mm.

Referring to FIG. 3, in the free state of the filter media 100 in which no external force is applied to the filter media 100, the plurality of elastic filaments 150 contract in a shape corresponding to the bent shape of the plurality of bends 110. It is. That is, in the free state of the filter medium 100, each of the plurality of elastic filaments 150 has a curved shape in which a plurality of S-shaped shapes alternate in successive opposite directions. The contracted and curved shape of the elastic filament forms a plurality of bends 110 in the filter media 100 while maintaining the bent shape of the plurality of bends 110. In detail, since the plurality of elastic filaments 150 are coupled to the first filtration member 120 or the second filtration member 130, the first filtration member 120 and the second filtration member 130 are contracted. The elastic filament 150 is bent in accordance with the shape of the bend to form the bent portion 110 of the filter media 100. Accordingly, the contracted and bent elastic filaments 150 form the bent part 110 in the filter media 100 and maintain the bent shape of the bent part 110.

When the retracted filter media 100 shown in FIG. 3 is stretched in the machine direction MD, the filter media 100 can be stretched within the elastic limits of the elastic filament 150. As an example, the elastic filament 150 may be elongated at an elongation of 100% to 300% in the machine direction MD. FIG. 5 shows side-by-side and stretched examples of filter media according to one embodiment. The example shown on the left side of FIG. 5 shows that the filter medium 100 is contracted while naturally forming the bent part 110 by the contracting force of the elastic filament 150, and the example shown on the right side of FIG. 5 shows the filter medium. It is shown that 100 is drawn to the maximum in the machine direction MD. The unit length SL of the elastic filament 150 of the maximum stretched filter media 100 may have a length that is 100% to 300% longer than the unit length CL of the contracted elastic filament 150.

The elastic filament 150 forming the bent part 110 may be coupled to the first filtration member 120 and the second filtration member 130 in the state of the elongation shown at the right side of FIG. 5. Thereafter, as the elastic filament 150 contracts in the machine direction MD, the elastic filament 150 partially pulls the first and second filtration members 120 and 130 in the machine direction MD, As a result, the bent part 110 is generated in the filter medium 100 while the first and second filtration members 120 and 130 are bent.

In addition, each of the plurality of elastic filaments 150 restores the shape stretched by the straight line shown on the right side of FIG. 5 to the shape corresponding to the curved shape of the bent portion 110 shown on the left side of FIG. 5. May have resilience. This restoring force may be embedded in the elastic filament 150 during the manufacture of the elastic filament 150.

As described above, the elastic filament 150 is stretchable and retractable in the machine direction MD. In addition, the elastic filament 150 is elastically restored in response to external forces in a direction perpendicular to the machine direction MD and the transverse direction CD (for example, the vertical direction VD in FIG. 3) due to its elasticity. Can be. Accordingly, the plurality of bends 110 may also be elastically restored to resist the external force in the direction perpendicular to the machine direction MD and maintain the bent shape. Therefore, even when the filter medium 100 or the fabric including the filter medium is unwound or rolled up after being rolled up or rolled up in a roll shape, the curved shape of the plurality of bent parts 100 may be maintained.

Since the elastic filament 150 creates the bent portion 110 by partially pulling the first and second filtration members 120 and 130 in the machine direction MD, the bent portion 110 may have different dimensions. . For example, as shown in FIG. 3, the widths W1 and W2 in the machine direction MD of the bend 110 may be different from each other. In addition, as shown in FIG. 3, some of the bends 110 may have a height greater or smaller than that of the other part.

Due to the shrinkage characteristics of the elastic filaments 150, each cross-sectional shape of the bent portion 110 may have an arc shape. As shown in FIG. 3, the cross-sectional shape of the arc shape of the bent portion 110 may be curved with different curvatures. Due to the shrinking properties of the elastic filament 150, neighboring bends 110 may partially overlap in the machine direction MD. As shown in FIG. 3, in the bend 110 bent by the elastic filament 150, the neighboring bends 110 partially overlap in the machine direction MD (ie, in the machine direction MD). The bends 110 may be continuous in the machine direction MD, such that a portion of another bend that is adjacent within one bend is located). As such, since the plurality of bends 110 have a bent shape shown in FIG. 3, the filter media 100 may have a wider surface area and may have an improved collection capability.

As an example, the filter media 100 may have 5 to 15 bends 110 per unit cm in the machine direction MD. Thus, the filter media 100 has a number of fine bends 110. Due to the plurality of minute bends 110, the filter media 100 may be used in a filter apparatus of various sizes and may be used as a filter media of a filter apparatus applied to a narrow space.

6 illustrates steps of a method of making a filter media according to one embodiment. 7 schematically illustrates a manufacturing apparatus for the manufacture of a filter media according to one embodiment. 3, 6, and 7 together, an embodiment of a method of manufacturing a filter media is described.

6 and 7, a method of manufacturing a filter medium according to an embodiment may include transferring the lamination material to lamination rolls 211 and 212 (S100), and laminating the lamination material ( Lamination step (S200), and forming a plurality of bent portion (110) in the laminated material (S300).

By step S100, the materials constituting the filter media 100 shown in FIG. 3 are transferred to the paper rolls 211, 212. The transferring of the paper material (S100) may include transferring the first and second filtration members 120 and 130 to the lamination rolls 211 and 212 (S110), and the first and second filtration members 120 and 120. The filaments 151, 152, 153, which are embedded between the 130 and the above-described elastic filaments 150, which bend the first and second filtration members 120, 130, are transferred to the lamination rolls 211, 212. Step S120 is included.

By the step S110, the first and second filtration members 120 and 130 are transferred to the pair of lamination rolls 211 and 212. The first filtration member 120 and the second filtration member 130 are transferred to the paper rolls 211 and 212 in different directions. The first filtering member 120 may be the aforementioned air through nonwoven fabric or the spunbond nonwoven fabric, and the second filtering member 130 may be the aforementioned melt blown nonwoven fabric. Alternatively, both the first filtering member 120 and the second filtering member 130 may be the meltblown nonwoven fabric described above.

During step S110, the adhesive 140 described above may be applied to at least one or both of the first filtration member 120 and the second filtration member 130. The adhesive 140 may be applied to the first filtration member 120 or the second filtration member 130 by an adhesive applicator 220. The adhesive applicator 220 may apply the adhesive 140 described above to the first filtration member 120 or the second filtration member 130 in a basis weight of 0.3 gsm to 2.0 gsm by a spraying method. Alternatively, the adhesive applicator 220 may apply the adhesive 140 described above by a slot die coating method. 8 shows an example of a slot die coating method. Adhesive applicator 220 may include a slot die 221 illustrated in FIG. 8, with adhesive 140 having a thickness of 0.3 gsm to 2.0 gsm through slot 222 of slot die 221. The basis weight may be applied to the first filtration member 120 or the second filtration member 130.

In operation S120, the filaments 151, 152, and 153, which are the aforementioned elastic filaments, may be supplied between the first and second filtration members 120 and 130.

Transferring the filament to the lamination roll (211, 212) (S120), the step (S121) of extruding the plurality of elastic filaments 150, and the plurality of extruded filaments 151 extruded to have elastic Stretching the filament 151 in the machine direction (MD) while quenching by a chill roll (chill roll) (S122), and the stretched plurality of filaments 152 toward the lamination rolls (211, 212) Transfer between the first and second filtration member (120, 130) (S123).

By the step S121, the plurality of filaments 151, which are continuous in the machine direction MD and spaced apart in the transverse direction CD, are respectively extruded. Step S121 may be performed by extruding the filament raw material forming the elastic filament 150 by an extruder 230. The filament raw material forming the elastic filament 150 may be injected into the extruder 230. The filament raw material may include a styrene block copolymer (SBC), a styrene-ethylene / butylene-styrene block copolymer (SEBS), or an olefin block copolymer (OBC). Alternatively, the filament raw material may include an elastic copolymer that can be elastically recovered and has an elongation of about 450%. The filament raw material introduced into the extruder 230 may be melted at 246 ° C. to 254 ° C. and injected into the die head 231 of the extruder 230. A plurality of filaments 151 may be continuously extruded from the die head 231 in the machine direction MD. In addition, each of the plurality of filaments 151 may be extruded at intervals of 2.5 mm to 10.0 mm in the lateral direction (CD). In this regard, the die head 231 may have a plurality of extruded holes (not shown) spaced at the interval in the cross direction CD.

In step S122, the plurality of extruded filaments 151 are stretched while being quenched. Step S122 may be performed using the cooling roll 240.

Referring to FIG. 7, the cooling roll 240 may include a first cooling roll 241 and a second cooling roll 242 arranged vertically above the lamination rolls 211 and 212 and rotating in different directions. Can be. The first cooling roll 241 and the second cooling roll 242 may have a temperature of 21 ° C to 32 ° C. The plurality of extruded filaments 151 are first contacted with the surface of the first cooling roll 241, and are transferred to the second cooling roll 242 side by the rotation of the first cooling roll 241. Thereafter, the filament 152 cooled by the first cooling roll 241 is in contact with the surface of the second cooling roll 242, and the paper rolls 211 and 212 are rotated by the rotation of the second cooling roll 242. Is transported to the side. By exchanging heat between the plurality of extruded filaments 151 and the first cooling roll 241 and the second cooling roll 242, the plurality of extruded filaments 151 are cooled and have strength and elasticity.

Referring to FIG. 7, the plurality of extruded filaments 151 may be transferred to the lamination rolls 211 and 212 by, for example, an S shape by the first cooling roll 241 and the second cooling roll 242. Therefore, the part which contacts the 1st cooling roll 241 and the 2nd cooling roll 242 in the extruded filament 151 differs, and it contacts the 1st cooling roll 241 and the 2nd cooling roll 242. The parts are located opposite each other with respect to the machine direction MD. The plurality of extruded filaments 151 may be stretched in the machine direction MD while being transported by the cooling roll 240. The second cooling roll 242 is rotated at a faster speed than the first cooling roll 241. Accordingly, the conveying speed of the extruded filament 151 by the second cooling roll 242 is greater than the conveying speed of the extruded filament 151 by the first cooling roll 241. Accordingly, the extruded filament 151 may be stretched in the machine direction MD while passing through the second cooling roll 242. As such, the stretching of the extruded filament 151 may be performed by a difference in rotational speeds of the first cooling roll 241 and the second cooling roll 242. Regarding the stretching of the filament, the rotational speed of the first cooling roll 241 and the rotational speed of the second cooling roll 242 may be determined to draw the extruded filament 151 at an elongation of 300% to 450%. Can be. The extruded filament 151 may be stretched such that the unit length of the filament after stretching is 300% to 450% longer than the unit length of the filament 151 before stretching.

By step S123, the stretched filament 152 is conveyed to the paper rolls 211 and 212 in the machine direction MD. Regarding step S123, a feed roll 243 disposed between the second cooling roll 242 and the lamination roll 211 212 and positioned vertically above the lamination rolls 212 and 212 is used. The feed roll 243 supplies the stretched filaments in the vertical direction between the first and second filtration members 120 and 130. Further, in step S123, the conveying speed of the stretched filament 153 conveyed by the lamination rolls 211, 212 is of the cooled and stretched filament 152 conveyed by the second cooling roll 242. It may be greater than the feed rate. Accordingly, the cooled and stretched filament 153 can be further stretched.

By the step S200, the lamination material (the first filtration member 120, the second filtration member 130 and the stretched filament 153) is laminated by the lamination rolls 211, 212, so that the bent portion 110 is A filter medium 100A that is not yet formed is formed.

A plurality of bends 110 are formed by the step (S300). The filter media 100A laminated by the lamination rolls 211 and 212 may be conveyed by a transfer roll (not shown) located downstream of the lamination rolls 211 and 212 in the machine direction MD. As the feed rolls located downstream of the lamination rolls 211 and 212 rotate at a speed lower than the rotational speeds of the lamination rolls 211 and 212, a plurality of elongated filaments 153 present inside the filter media 100A are formed. It flexes while contracting in the machine direction MD. By the contracting force in the machine direction MD of the plurality of elongated filaments 153, the first and second filtration members 120 and 130 are bent while being contracted in the machine direction MD, and in the machine direction MD. A plurality of bends 110 are formed alternately in series and each extending in the transverse direction CD. Before the filter media 100A is laminated, the stretched filament 153 is elongated at an elongation of 300% to 450% compared to the extruded filament 151. In the laminated filter media 100A, the stretched filaments 153 may be stretched in the machine direction MD at an elongation of 100% to 300% due to the limitation of the first and second filtration members 120 and 130. Can be.

In order to confirm the filtration efficiency and the differential pressure performance of the filter medium according to the embodiment, the filtration efficiency verification test, differential pressure performance verification test, air permeability confirmation for the filter media of the test example according to the embodiment and the filter media according to the comparative example Tests were performed. 9 to 13, the improvement of the filtration efficiency, the differential pressure performance, and the ventilation of the filter medium according to one embodiment will be described.

9 is a graph showing the filtration efficiency of the filter medium of Test Example 1 and the filter medium of Comparative Example 1 according to an embodiment, Figure 10 is a filter medium of the filter medium of Test Example 1 and the filter of Comparative Example 1 according to an embodiment It is a graph which shows the differential pressure of a filter medium, FIG. 11 is a table which shows the air permeability of the filter medium of the test example 1 and the filter medium of the comparative example 1 which concerns on an Example.

In Test Example 1 and Comparative Example 1 in FIGS. 9 to 11, an unstatically treated spunbond nonwoven fabric is used as the first filtration member, and an unmelted meltblown nonwoven fabric is used as the second filtration member. However, Test Example 1 has the aforementioned bent portion, whereas Comparative Example 1 does not have the aforementioned bent portion.

Referring to FIG. 9, it can be seen that the filter medium according to the embodiment has a filtration efficiency of about 48% improved at an air flow rate of 32 lpm and about 10% at an airflow amount of 95 lpm, compared to a filter medium according to a comparative example. have.

Referring to FIG. 10, it can be seen that the filter medium according to the embodiment has a pressure difference performance of about 16% at a blowing amount of 32 lpm and a pressure difference performance of about 30% at a blowing amount of 95 lpm, compared to a filter medium according to a comparative example. have.

Referring to FIG. 11, the filter media according to the embodiment has a ventilation of about 87 cfm, while the filter media according to the comparative example has a ventilation of about 60 cfm. Therefore, it can be seen that the filter medium according to one embodiment has about 45% improved ventilation compared to the filter medium according to the comparative example.

12 and 13 show the filtration efficiency and the differential pressure performance in the filter media of various test examples and the filter media of various comparative examples. 12 is a graph showing the filtration efficiency and the differential pressure performance at the air flow amount of 32lpm of the filter media of the test example according to the embodiments and the filter media according to the comparative examples, Figure 13 is a filter media of the test example according to the embodiments It is a graph showing the filtration efficiency and the differential pressure performance at the air flow amount of 95lpm of the filter medium according to the comparative examples.

12 and 13, Test Example 2 and Test Example 3 are filter media in which two meltblown nonwoven fabrics subjected to correction processing and the above-described filaments are laminated, and have the aforementioned bent portion. The meltblown nonwoven fabric of Test Example 2 has a basis weight of 20 gsm, and the meltblown nonwoven fabric of Test Example 3 has a basis weight of 35 gsm. 12 and 13, Comparative Examples 2 to 6 include a meltblown nonwoven fabric subjected to electrostatic treatment and do not have the aforementioned bent portion. The filter media of Comparative Example 2 contains only one meltblown nonwoven fabric having a basis weight of 20 gsm. Comparative Example 3 is a filter medium in which two meltblown nonwoven fabrics having a basis weight of 20 gsm are laminated. Comparative Example 4 is a filter medium in which three meltblown nonwoven fabrics having a basis weight of 20 gsm are laminated. Comparative Example 5 is a filter medium in which one meltblown nonwoven fabric having a basis weight of 35 gsm and one meltblown nonwoven fabric having a basis weight of 20 gsm are laminated. Comparative Example 6 is a filter medium in which two meltblown nonwoven fabrics having a basis weight of 35 gsm are laminated.

Referring to FIG. 12, the filter media of Test Example 3 and the filter media of Comparative Examples 4 and 5 have similar filtration efficiencies, but the filter media of Test Example 3 is more remarkable than the filter media of Comparative Examples 4 and 5 It can be confirmed that it has a low differential pressure. Referring to FIG. 13, the filter media of Test Example 3 and the filter media of Comparative Examples 4 to 6 have similar filtration efficiencies, but the filter media of Test Example 3 is more remarkable than the filter media of Comparative Examples 4 to 6. It can be confirmed that it has a low differential pressure.

Although the technical spirit of the present disclosure has been described with reference to some embodiments and the accompanying drawings, the technical spirit and scope of the present disclosure may be understood by those skilled in the art. It will be appreciated that various substitutions, modifications, and alterations can be made in the scope. Also, such substitutions, modifications and variations are intended to be considered within the scope of the appended claims.

100: filter media, 110: bend, 120: first filtration member, 130: second filtration member, 140: adhesive, 150: elastic filament, 151: extruded filament, 152: cooled filament, 153: elongated filament, 211: lamination roll, 212: lamination roll, 220: adhesive applicator, 221: slot die, 230: extruder, 240: cooling roll, 241: first cooling roll, 242: second cooling roll, MD: machine direction, CD : Transverse direction, 100A: filter media, SL: elongated unit length, CL: deflated unit length

Claims (20)

A plurality of bends alternately connected in the machine direction and extending in the transverse direction orthogonal to the machine direction,
First and second filtration members respectively forming a portion and a remaining portion of the plurality of bends in the machine direction and the transverse direction;
An adhesive applied to at least one of the first and second filtration members,
A curved shape of the plurality of bends joined by at least one of the first and second filtration members by the adhesive between the first and second filtration members, each oriented in the machine direction, and spaced apart in the lateral direction, respectively A plurality of elastic filaments contracted to a shape corresponding to the plurality of elastic filaments to maintain the curved shape,
Retractable in the machine direction by the contracting force of the elastic filament,
Filter media. The method of claim 1,
The plurality of elastic filaments extend continuously in the machine direction,
Filter media. The method of claim 1,
The plurality of elastic filaments have a diameter of 0.5mm to 1.0mm,
Each of the plurality of elastic filaments are spaced at intervals of 2.5mm to 10.0mm in the transverse direction,
Filter media. The method of claim 1,
The plurality of elastic filaments are stretchable in the machine direction at an elongation of 100% to 300%,
Filter media. The method of claim 1,
The material constituting the plurality of elastic filaments includes any one of a styrene block copolymer, a styrene-ethylene / butylene-styrene block copolymer, and an olefin block copolymer,
Filter media. The method of claim 1,
The plurality of bends have different widths in the machine direction,
Filter media. The method of claim 1,
Each of the plurality of bends has a cross-sectional shape of an arc shape, wherein the arc shapes are curved with different curvatures,
Filter media. The method of claim 1,
Wherein the plurality of bends are continuous in the machine direction such that adjacent bends partially overlap in the machine direction,
Filter media. The method of claim 1,
5 to 15 said bends per unit cm
Filter media. The method of claim 1,
One of the first and second filtration members has a basis weight of 10 gsm to 100 gsm and includes an unstaticized airthrough nonwoven or spunbond nonwoven fabric,
The other of the first and second filtration members comprises a meltblown nonwoven fabric having an electrostatic treatment having a basis weight of 10 gsm to 50 gsm,
Filter media. The method of claim 1,
Wherein the first and second filtration members have a basis weight of 10 gsm to 50 gsm and comprise an electrostatic meltblown nonwoven fabric,
Filter media. Transferring the first and second filtration members having at least one adhesive applied to the pair of lamination rolls,
Extruding a plurality of filaments continuous in the machine direction and spaced apart in the transverse direction orthogonal to the machine direction in the machine direction,
Stretching the extruded plurality of filaments in the machine direction while cooling by a chill roll;
Transferring the stretched plurality of filaments between the first and second filtration members toward the lamination roll;
Laminating the plurality of filaments drawn with the first and second filtration members by the lamination roll;
Contracting the first and second filtration members in the machine direction by the contracting force of the stretched plurality of filaments to form a plurality of bends that are alternately connected in the machine direction and respectively extend in the transverse direction. doing,
Method of manufacturing filter media. The method of claim 12,
The cooling roll includes a first cooling roll and a second cooling roll arranged vertically above the paper roll and rotating in different directions,
The plurality of filaments are in contact with the second cooling roll after being in contact with the first cooling roll,
In the stretching of the plurality of filaments, the conveying speed of the plurality of filaments by the second cooling roll is greater than the conveying speed of the plurality of filaments by the first cooling roll,
Method of manufacturing filter media. The method of claim 13,
In the conveying of the plurality of filaments, the conveying speed of the plurality of filaments by the lamination roll is greater than the conveying speed of the plurality of filaments by the second cooling roll,
Method of manufacturing filter media. The method of claim 12,
The stretching of the plurality of filaments may include stretching the plurality of filaments at an elongation of 300% to 450%.
Method for producing filter media. The method of claim 12,
In the step of extruding the plurality of filaments, each of the plurality of filaments are spaced at intervals of 2.5mm to 10.0mm in the transverse direction,
Method for producing filter media. The method of claim 12,
Extruding the plurality of filaments is performed by extruding the filament raw material by an extruder,
The filament raw material includes any one of a styrene block copolymer, a styrene-ethylene / butylene-styrene block copolymer and an olefin block copolymer,
Method for producing filter media. The method of claim 12,
In the step of transferring the first and second filtration member to the lamination roll, the adhesive is applied to at least one of the first and second filtration member by a slot die in a basis weight of 0.3gsm to 2.0gsm,
Method for producing filter media. The method of claim 12,
One of the first and second filtration members has a basis weight of 10 gsm to 100 gsm and comprises an unstaticized airthrough nonwoven or spunbond nonwoven fabric,
The other of the first and second filtration members has a basis weight of 10 gsm to 50 gsm and includes an electrostatic meltblown nonwoven fabric,
Method for producing filter media. The method of claim 12,
Wherein the first and second filtration members have a basis weight of 10 gsm to 50 gsm and comprise an electrostatic meltblown nonwoven fabric,
Method of manufacturing filter media.

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