JP2013031828A - Air filter, manufacturing method thereof, and air cleaner provided with the air filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the productivity as for an air filter, a manufacturing method thereof, and an air cleaner provided with the air filter.SOLUTION: The air filter includes a base material portion 14 consisting of an aggregate of fibers 17, and a minute fiber layer 15 consisting of an aggregate of nanofibers 18 bonded to the base material portion 14. The nanofiber 18 has a constitution in which a dimension A of an adhesive surface part 21 in contact with base material portion 14 in a width direction is larger than a dimension B of a non-adhesive surface part 22 out of contact with the base material portion 14 in the width direction.

Description

  The present invention relates to an air filter incorporated in an air conditioner and the like, a method for manufacturing the air filter, and an air cleaning device including the air filter.

  A conventional air filter includes a base material part and a fine fiber layer provided on the base material part, and the base material part and the fine fiber layer are configured to adhere with an adhesive (for example, Patent Documents). 1).

JP 2010-274144 A

  The problem in the conventional example is that productivity is low.

  That is, in order to increase the bonding strength between the base material portion and the fine fiber layer, the base material portion and the fine fiber layer are configured to adhere with an adhesive as described above, and an adhesion step using this adhesive is required. The productivity was reduced.

  Thus, the present invention aims to increase productivity.

  In order to achieve this object, the present invention comprises a base material portion made of a fiber assembly and a fine fiber layer made of a nanofiber assembly bonded to the base material portion, and the nanofiber comprises a base material The size in the width direction of the bonding surface portion with the part is larger than the size in the width direction of the non-bonding surface portion with the base material portion, thereby achieving the initial purpose. Is.

  As described above, the present invention includes a base material portion made of a fiber assembly and a fine fiber layer made of a nanofiber assembly bonded to the base material portion, and the nanofiber is bonded to the base material portion. Since the dimension in the width direction in the surface portion is larger than the dimension in the width direction in the non-adhesive surface portion with the base material portion, productivity can be improved.

  That is, in the present invention, when directly adhering the fine fiber layer composed of the nanofiber aggregate to the base material section composed of the fiber aggregate, the nanofibers in the width direction of the adhesive surface portion with the base material section. By making the dimensions larger than the dimension in the width direction in the non-adhesive surface portion with the base material portion, the fine fiber layer can be directly bonded to the base material portion without using an adhesive bonding step. As a result, the productivity can be increased by the amount that the bonding step is unnecessary.

  Further, the fine fiber layer is formed by laminating two or more kinds of nanofiber aggregates having different dimensions in the width direction in the non-adhesion surface portion with the base material portion, and thereby excellent for long-term use. Durability is obtained.

Sectional drawing of the air purifying apparatus provided with the air filter which shows Embodiment 1 of this invention Perspective view of the air filter Enlarged perspective view of the air filter Enlarged sectional view of the air filter The figure which shows the joint surface part of the nanofiber and base material part of the same air filter Schematic showing the manufacturing method of the same air filter Schematic sectional view of an air filter showing a second embodiment of the present invention The graph which shows the pressure loss change for every fiber diameter of an Example

  The air filter according to claim 1 of the present invention includes a base material portion made of a fiber assembly and a fine fiber layer made of a nanofiber assembly bonded to the base material portion. The dimension of the width direction in the adhesion surface part with a part is set as the structure larger than the dimension of the width direction in the non-adhesion surface part with a base material part. Thereby, since the adhesion area of a nanofiber and a base material part becomes large, the effect that it can adhere | attach firmly without using an adhesive agent is acquired.

  Further, the fine fiber layer is formed by laminating two or more kinds of nanofiber aggregates having different widthwise dimensions in the non-adhesion surface portion with the base material portion. Thereby, dusts having different sizes can be separated and collected in each layer, and durability against long-term use of the air filter can be obtained.

  Further, the fine fiber layer includes at least a nanofiber aggregate having a dimension in the width direction of the non-adhesive surface portion with the base material portion mainly of about 200 nm and a nanofiber assembly mainly of about 600 nm. . As a result, large dust can be collected in a coarse layer of 600 nm and fine dust can be collected in a dense layer of 200 nm. Sex can be obtained.

  In addition, if the basis weight of the two or more types of nanofiber aggregates is relatively small in size in the width direction in the non-adhesive surface portion with the base material portion, the long-term use The increase in pressure loss due to dust clogging can be suppressed.

  Moreover, the air purifier provided with the air filter according to any one of claims 1 to 4 can suppress degradation of the collection efficiency of the air filter due to separation of nanofibers from the base material for a long period of time. Therefore, it can be used for a long time. Furthermore, when the nanofiber assembly has a dimension in the width direction at the non-adhesive surface portion with the base material portion where the upstream layer is larger than the downstream layer with respect to the air flow, large dust is collected in the upstream layer. As a result, the load on the downstream layer can be reduced and the durability of the air filter for long-term use can be further increased.

  Moreover, it is a manufacturing method of the air filter in any one of Claim 1 to 4, Comprising: Air including the process of spraying on the surface of the said base material part, before the solvent dries the polymer solution which forms nanofiber. In the method for manufacturing a filter, the nanofibers have a flat shape so as to be along the surface of the fibers of the base material part at the part of the bonding surface with the base material part. Thereby, as for the nanofiber, the dimension of the width direction in the adhesion surface part with a base material part becomes larger than the dimension of the width direction in the non-adhesion surface part with a base material part. As a result, since the bonding area between the nanofiber and the base material portion is increased, the nanofiber can be firmly bonded to the base material portion without using an adhesive.

(Embodiment 1)
Embodiment 1 of the present invention will be described below with reference to the accompanying drawings.

  As shown in FIG. 1, the air purifier including the air filter of this embodiment includes a blower 2 and an air filter 3 in a main body case 1.

  The main body case 1 has a substantially vertically long box shape. The main body case 1 is provided with a substantially square-shaped intake port 4 on the front side surface portion thereof, and the main body case 1 is provided with a substantially square-shaped exhaust port 5. Yes. The exhaust port 5 is provided with a wind direction louver 6.

  The air blowing means 2 is provided in an air passage between the air inlet 4 and the air outlet 5 of the main body case 1, and has a scroll-shaped casing 7 and a blade 8 which is a centrifugal air fan provided in the casing 7. And the electric motor 9 that rotates the blade 8. The air filter 3 is located at the air inlet 4 of the main body case 1. The room air sucked into the main body case 1 from the air inlet 4 by the air blowing means 2 is sent to the air outlet 5 through the air filter 3. That is, the indoor air is cleaned by the air filter 3 and blown into the room.

  As shown in FIGS. 2 and 3, the air filter 3 includes a pleated filter medium part 10, and a frame-shaped shape holding part 11 provided on the outer periphery of the filter medium part 10 to hold the filter medium part 10 in a pleated shape. Formed from.

  As shown in FIG. 4, the filter medium part 10 includes a base material part 14 and a fine fiber layer 15 provided on the upstream side surface of the air flow blown to the base material part 14. As an example of the material of the base material part 14, it is the nonwoven fabric which is glass and resin. The fine fiber layer 15 is formed of fine fibers having a diameter of nanometer. Specifically, a plurality of nanofibers are intertwined to form the fine fiber layer 15.

  As shown in FIG. 5, the feature of this embodiment includes a base material portion 14 and a fine fiber layer 15 composed of an assembly of nanofibers 18 adhered to the base material portion 14. The dimension A in the width direction in the bonding surface portion 21 with the base material portion 14, specifically, the fiber 17 constituting the base material portion 14 is the width dimension in the non-bonding surface portion 22 with the base material portion 14. The configuration is larger than B.

  That is, since the base material portion 14 made of an assembly of fibers 17 and the fine fiber layer 15 made of an assembly of nanofibers 18 adhered to the base material portion 14 are provided, a fine fiber made of an assembly of nanofibers 18 is provided. The fiber layer 15 reduces the size of the eyes and improves the collection efficiency. Further, the nanofiber 18 has a configuration in which the dimension A in the width direction of the bonding surface portion 21 with the base material portion 14 is larger than the dimension B in the width direction of the non-bonding surface portion 22 with the base material portion 14. Since the bonding area between the nanofiber 18 and the base material portion 14 is increased, the nanofiber 18 can be directly bonded to the fiber 17. That is, the nanofibers 18 that are bonded to the fibers 17 have a larger dimension A in the width direction at the bonding surface portion 21 and can be firmly bonded without using an adhesive.

  Therefore, the productivity can be increased by the amount that the bonding step is not required.

  In order to make the dimension A in the width direction of the bonding surface portion 21 of the nanofiber 18 with the base material portion 14 larger than the dimension B in the width direction of the non-bonding surface portion 22 with the base material portion 14 in this way. In this case, since the nanofibers 18 are jetted in the vicinity of the base material part 14, the base material part 14 and the fine fiber layer 15 are separately formed from this point as well. Productivity can be increased rather than bonding the portion 14 and the fine fiber layer 15 together.

  Moreover, since the air filter 3 comprised in this way can suppress over a long period that the nanofiber 18 peels from the base material part 14 and a collection efficiency falls, as a result, collection efficiency In addition, the high collection efficiency can be secured for a long time.

  Here, a method for manufacturing the air filter 3 will be described. As shown in FIG. 6, the manufacturing facility includes a conveying means 19 that carries the base material portion 14 and conveys it in the horizontal direction, and a nozzle 20 that is positioned above the conveying means 19.

  The nozzle 20 sprays a polymer solution that forms the nanofibers 18 on the surface that is the upper surface of the plate-like base material portion 14 that is conveyed by the conveying means 19.

  In the manufacture of the air filter 3, first, the polymer material solution forming the nanofiber 18 is discharged from the nozzle 20 toward the base material part 14 while the flat base material part 14 is transported by the transport means 19. Here, a voltage of about +20 KV is applied to the nozzle 20, and the conveying means 19 is grounded. Due to this potential difference, the polymer solution that forms the nanofibers 18 discharged from the nozzle 20 is transferred to the base material portion. It adheres to the whole surface of 14, and forms the fine fiber layer 15. FIG.

  The feature of this embodiment is that in the step of spraying the polymer solution onto the surface of the base material part 14, the polymer polymer solution is sprayed onto the surface of the base material part 14 before the solvent dries. It is.

  That is, before the solvent of the polymer polymer solution blown out from the nozzle 20 is dried, the polymer polymer solution reaches the surface that is the upper surface of the substrate part 14 so that the gap between the nozzle 20 and the substrate part 14 is reached. Adjust the distance.

  As a result, the polymer solution that forms the nanofibers 18 is sprayed onto the surface of the base material portion 14 while leaving the solvent, so that the nanofibers 18 are separated from the base material portion 14 as shown in FIG. It becomes a flat shape so that it may follow the surface of the fiber 17 of the base material part 14 in the adhesive surface part 21 of this. That is, as described above, in the nanofiber 18, the dimension A in the width direction at the bonding surface portion 21 with the base material portion 14 is larger than the dimension B in the width direction at the non-bonding surface portion 22 with the base material portion 14. Become. As a result, since the bonding area between the nanofiber 18 and the base material portion 14 is increased, the nanofiber 18 can be firmly bonded to the base material portion 14 without using an adhesive. Therefore, the productivity can be increased by the amount that the bonding step is not required.

  Moreover, since it can suppress for a long time that the nanofiber 18 peels from the base material part 14 and this reduces a collection efficiency, while improving a collection efficiency as a result, a high collection efficiency Can be secured over a long period of time.

(Embodiment 2)
Embodiment 2 of the present invention will be described below with reference to the accompanying drawings.

  As shown in FIG. 7, the air filter 3 according to the present embodiment includes a fine nanofiber layer 15 having a dense nanometer in which a dimension B in the width direction at least on a non-adhesion surface portion with the base material portion 14 is mainly about 200 nm. It is composed of a filter medium formed by laminating a fiber assembly 23 and a coarse nanofiber assembly 24 mainly having a thickness of about 600 nm. Here, the fiber diameter is almost a normal distribution, and the above-mentioned 200 nm and 600 nm are the numerical values of the center diameter and including the variation of the standard deviation, and therefore are described as “mainly about 200 nm” and “mainly about 600 nm”. Yes.

  The dimension B in the width direction on the non-contact surface with the base material part 14 can be considered by replacing with the fiber diameter of the nanofiber. As shown by the arrows in the figure, air passes through the coarse nanofiber aggregate 24 having a fiber diameter of about 600 nm and the dense nanofiber aggregate 23 having a fiber diameter of 200 nm in this order, and flows out from the base material portion 14.

  When thick fibers and thin fibers are sprayed so as to have the same weight per unit area, if the materials are the same, the thick fibers will occupy fewer fibers per unit volume and the fiber spacing will be larger. As a result, the structure becomes rough. If the structure is dense, high dust collection efficiency can be obtained, but when filtering atmospheric dust containing particles of various sizes, large particles such as 1 μm in diameter are trapped in a dense nanofiber aggregate of 200 nm. As a result, the air gap is closed, the pressure loss increases rapidly, and the characteristics of the air filter rapidly decrease. By trapping large particles in a layer having a rough structure, a rapid increase in pressure loss can be suppressed. Thus, separating and collecting large particles upstream and small particles downstream is advantageous for long-term use.

  In order to prevent the fine fiber layer 15 from being damaged, a protective layer 25 may be provided. The protective layer 25 may be made of the same material as the base material, or a heat-meltable resin nonwoven fabric may be used. When a heat-meltable nonwoven fabric is used, the effect that the fine fiber layer 15 can be fixed by heating is obtained. The base material part 14 and the protective layer 25 are preferably those that have low pressure loss and do not impede the inflow of air. However, when there is a difference in the dust collection efficiency of the single substance, for example, the diameter is 1 μm on the upstream side of the air flow. If the configuration of the nanofiber assembly is changed so that a material capable of collecting such large particles as described above is disposed, the particles can be separated and collected more effectively.

  Non-adhesive surface portion of nanofiber assembly with base material portion for air filter medium comprising base material portion made of fiber aggregate and fine fiber layer made of nanofiber aggregate bonded to base material portion The dimension B in the width direction, that is, the fiber diameters of 145 nm, 387 nm, 589 nm, and laminates of 145 nm and 589 nm were produced by the method described in Embodiment 1.

  At this time, the fiber diameter has a normal distribution, but the standard deviation is 30 nm for the center diameter of 145 nm, 110 nm for the center diameter of 387 nm, and 169 nm for the center diameter of 589 nm, and the variation increases as the fiber diameter increases. The tendency to do was seen. Each of these was inhaled with cigarette smoke and observed changes in pressure loss. Table 1 shows these specification tables.

  All samples were based on glass paper, and the basis weight of the nanofibers was adjusted so that the initial dust collection efficiency for 0.3 μm dust was 98% or more.

  The result is shown in FIG. A nanofiber aggregate having a fiber diameter of 145 nm can provide high dust collection performance with a small basis weight and low initial pressure loss. However, since the structure is dense, the rate of increase in pressure loss relative to the load caused by tobacco smoke is high. On the other hand, as the fiber diameter increases, the initial pressure loss increases, but the increase rate of the pressure loss decreases. In the case where these layers were laminated, the rate of increase in pressure loss could be lowered for the thin nanofiber aggregate having a fiber diameter of 145 nm with a relatively small basis weight.

  The fiber diameter, basis weight, and lamination ratio of the nanofibers are such that a thin nanofiber aggregate with a fiber diameter of 145 nm contributes to the reduction of the initial pressure loss, and a thick nanofiber aggregate with a fiber diameter of 589 nm suppresses the rate of increase in pressure loss. For example, in the case of targeting tobacco smoke, the nanofiber aggregate in the width direction of the non-adhesive surface portion with the base material portion may be selected. It can be said that if the nanofiber aggregate having the dimension B, that is, the fiber diameter of 100 nm to 200 nm, and the nanofiber aggregate having a fiber diameter of 500 nm to 650 nm are laminated, a more effective configuration can be achieved.

  As described above, the present invention can not only improve productivity, but also improve the collection efficiency, and further ensure high collection efficiency over a long period of time.

  Therefore, it is expected to be utilized as an air filter for home use or office use, a method for manufacturing the air filter, and an air purifier equipped with the air filter.

DESCRIPTION OF SYMBOLS 1 Main body case 2 Air blowing means 3 Air filter 4 Intake port 5 Exhaust port 6 Wind direction louver 7 Casing 8 Blade 9 Electric motor 10 Filter material part 11 Shape holding part 14 Base material part 15 Fine fiber layer 17 Fiber 18 Nanofiber 19 Conveying means 20 Nozzle 21 Adhesive surface portion 22 Non-adhesive surface portion 23 Dense nanofiber aggregate 24 Coarse nanofiber aggregate 25 Protective layer A, B Dimensions in the width direction

Claims (6)

A base portion made of an aggregate of fibers, and a fine fiber layer made of an aggregate of nanofibers adhered to the base portion; the nanofiber has a width-direction dimension at an adhesive surface portion with the base portion An air filter having a configuration larger than the dimension in the width direction in the non-adhesive surface portion with the base material portion. The air filter according to claim 1, wherein the fine fiber layer is formed by laminating two or more kinds of nanofiber aggregates having different widthwise dimensions in a non-adhesion surface portion with the base material portion. The fine fiber layer includes at least a nanofiber aggregate having a width dimension of mainly 100 nm to 200 nm and a nanofiber aggregate mainly having a thickness of 500 nm to 650 nm in a non-adhesive surface portion with the base material portion. Item 3. The air filter according to Item 2. The basis weight of the two or more kinds of nanofiber aggregates is relatively smaller than those having a smaller size in the width direction in the non-bonding surface portion with the base material portion. Or the air filter in any one of 3. 5. An air cleaning device comprising the air filter according to claim 1, wherein a dimension in a width direction of a non-adhesive surface portion of the nanofiber assembly with respect to the base portion is upstream of the air flow. An air cleaning device, wherein the layer is larger than the downstream layer. The method for producing an air filter according to any one of claims 1 to 4, comprising a step of spraying a polymer solution that forms nanofibers onto the surface of the base before the solvent dries. Production method.

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