JP3013906B2 - Electret fiber filter - Google Patents
Electret fiber filterInfo
- Publication number
- JP3013906B2 JP3013906B2 JP3201360A JP20136091A JP3013906B2 JP 3013906 B2 JP3013906 B2 JP 3013906B2 JP 3201360 A JP3201360 A JP 3201360A JP 20136091 A JP20136091 A JP 20136091A JP 3013906 B2 JP3013906 B2 JP 3013906B2
- Authority
- JP
- Japan
- Prior art keywords
- fibers
- melt
- filter
- fiber
- nonwoven fabric
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
- D04H3/016—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the fineness
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
- D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
- D04H3/16—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion
Landscapes
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Filtering Materials (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、クリーンルーム用フィ
ルター、ビル空調用フィルター、掃除機用フィルター、
空気清浄機用フィルター、エアコン用フィルター、ＯＡ
機器用フィルターなどのエアフィルターや液体用フィル
ターなどに用いることのできる高い濾過特性を有するエ
レクトレット繊維フィルターに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter for a clean room, a filter for a building air conditioner, a filter for a vacuum cleaner,
Air purifier filter, air conditioner filter, OA
The present invention relates to an electret fiber filter having high filtration characteristics, which can be used for an air filter such as a device filter, a liquid filter, and the like.
【０００２】[0002]
【従来の技術】メルトブロー不織布をフィルターに用い
る開示技術は特開平１−２４６４５４号公報に記載があ
る。この公報には溶融吹付けによって形成した熱可塑性
繊維のうち、３３％以上の部分が、好ましくは４０％以
上の部分が溶融した凝集塊として存在し、凝集塊の繊維
の交差部分の大部分が融着点であることを特徴とする喫
煙用品用フィルターが開示されている。この公報には従
来の溶融吹付けウエブは３５％の凝集塊を含んでいるの
に対し、その凝集塊の量を多くした方が喫煙用品用フィ
ルターとしてはフィルターの硬度と吸引抵抗が小さくで
きるということから望ましいフィルターとなるのであ
る。この開示技術の凝集塊とは溶融した又は部分的に溶
融した繊維又はフィラメントの束を意味している。2. Description of the Related Art Japanese Patent Application Laid-Open No. 1-246454 discloses a disclosed technique using a melt-blown nonwoven fabric for a filter. In this publication, 33% or more, preferably 40% or more, of the thermoplastic fibers formed by melt spraying are present as agglomerates, and most of the intersections of the fibers of the agglomerates are present. A smoking article filter characterized by a fusion point is disclosed. According to this publication, a conventional melt-blown web contains 35% of agglomerates, whereas increasing the amount of the agglomerates can reduce the filter hardness and suction resistance of a smoking article filter. This makes it a desirable filter. Agglomerates of the disclosed technology refer to bundles of molten or partially molten fibers or filaments.
【０００３】一般に溶融吹付け法でつくられるメルトブ
ロー不織布は特開平１−２４６４５４号公報に記載され
ているごとく、繊維が無作為に相互にもつれるため、そ
の結果として単繊維が繊維の長手方向に部分的に並列的
に融着して束状繊維が発生し、この量が全繊維中に３５
％含まれている。特開平１−２４６４５４号公報ではこ
の束状繊維の量が多い程喫煙用品用フィルターとしては
望ましいフィルターとなるのではあるが、エレクトレッ
トフィルターにあっては、この束状繊維の量が多いとフ
ィルターの濾過特性が悪くなるという問題があった。[0003] Generally, as described in JP-A-1-246454, a melt-blown nonwoven fabric produced by a melt spraying method has fibers entangled with each other at random. The fibers are fused in parallel to form bundled fibers, and this amount is 35% of the total fibers.
%include. In Japanese Patent Application Laid-Open No. Hei 1-246454, it is preferable that the amount of the bundled fiber is larger as the amount of the bundled fiber is larger. There was a problem that filtration characteristics deteriorated.
【０００４】[0004]
【発明が解決しょうとする課題】本発明は、前記従来技
術の問題を解決し優れた濾過特性と低圧損特性を有する
エレクトレットフィルターを提供することでる。SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide an electret filter having excellent filtration characteristics and low pressure loss characteristics.
【０００５】[0005]
【課題を解決するための手段】本発明はかかる問題に鑑
み鋭意検討した結果、本発明に到達したものであり、メ
ルトブロー不織布における単繊維の平均繊維径が０．８
〜３μｍであり、繊維の長手方向に部分的に並列的に融
着してなる束状繊維が全繊維中に１０〜３０％含まれて
なることを特徴とするエレクトレットフィルターに関す
る。Means for Solving the Problems The present invention has been made as a result of intensive studies in view of the above problems, and the present invention has been accomplished.
The present invention relates to an electret filter characterized in that bundle fibers, which are fused in a partly parallel manner in the longitudinal direction of the fibers, are contained in the entire fibers by 10 to 30%.
【０００６】本発明においてメルトブロー不織布とは溶
融吹付け法でつくられる極細繊維の不織布であり、繊維
の長手方向に部分的に並列的に融着してなる束状繊維と
は単繊維が相互に長手方向にわって数１０μｍ以上にわ
たって束状に重なり合って一体となっている形態の繊維
であり、複数本の単繊維の集合体繊維である。本発明に
おいて、かかる並列的に融着してなる束状繊維の含有率
の定量化はメルトブロー不織布の断面の電子顕微鏡写真
から繊維断面の撮影されている１００本以上の繊維につ
いて、その繊維まわり融着状態を観察し単繊維本数と束
状繊維本数を数える方法でなされる。電子顕微鏡用サン
プルには液体窒素で冷却したメルトブロー不織布を破断
して準備し、電子顕微鏡の倍率を１２００倍で写真撮影
する。In the present invention, the melt-blown non-woven fabric is a non-woven fabric of ultra-fine fibers produced by a melt spraying method, and a bundle of fibers partially and parallelly fused in the longitudinal direction of the fibers is a single fiber. It is a fiber in the form of being bundled together over several tens of μm or more along the longitudinal direction and integrated, and is an aggregate fiber of a plurality of single fibers. In the present invention, the quantification of the content of the bundle-shaped fibers fused in parallel is carried out for 100 or more fibers whose cross section is photographed from an electron micrograph of the cross section of the melt-blown nonwoven fabric. This is done by observing the state of attachment and counting the number of single fibers and the number of bundled fibers. A sample for an electron microscope is prepared by breaking a melt-blown nonwoven fabric cooled with liquid nitrogen, and photographed at a magnification of 1200 times with an electron microscope.
【０００７】本発明において、メルトブロー不織布の断
面写真から束状繊維の含有率を求めたのは、メルトブロ
ー不織布の表面や裏面ではメルトブロー不織布における
厚さ方向の束状繊維の融着状態が正確に把握できないた
めである。本発明において、束状繊維の含有率は全繊維
に対して１０〜３０％が好ましい。束状繊維の含有率が
３０％を越えるとエレクトレット化による単繊維への荷
電効率が著しく低下する。一方、１０％未満になるとメ
ルトブロー不織布の充填密度が大きくなりすぎ圧力損失
が高くなりすぎると言う問題がある。つまり、粒子除去
効率と圧力損失は二律背反する特性であり、それらを同
時に満足するエレクトレットフィルターの繊維集合体構
造としては繊維の長手方向に部分的に並列的に融着して
なる束状繊維の含有率が１０〜３０％であることが好ま
しいのである。フィルターの濾過特性を表す尺度として
次式〔数１〕がある。In the present invention, the content of bundled fibers is determined from the cross-sectional photograph of the melt-blown nonwoven fabric because the fusion state of the bundled fibers in the thickness direction of the meltblown nonwoven fabric is accurately grasped on the front and back surfaces of the meltblown nonwoven fabric. This is because they cannot. In the present invention, the content of the bundle fibers is preferably 10 to 30% based on all fibers. If the content of the bundle fiber exceeds 30%, the charging efficiency of the single fiber due to electretization is significantly reduced. On the other hand, if it is less than 10%, there is a problem that the filling density of the meltblown nonwoven fabric becomes too large and the pressure loss becomes too high. In other words, the particle removal efficiency and the pressure loss are properties that conflict with each other, and the fiber aggregate structure of an electret filter that satisfies them at the same time contains bundled fibers partially fused in parallel in the longitudinal direction of the fibers. It is preferred that the ratio be 10 to 30%. The following equation (Equation 1) is used as a scale representing the filtering characteristics of the filter.
【０００８】[0008]
【数１】(Equation 1)
【０００９】上式において、Ｅは粒子除去効率、ΔＰは
圧力損失である。本発明におけるメルトブロー不織布の
単繊維の平均繊維径は０．５〜３μｍが好ましい。この
平均繊維径とは任意に１００本以上の単繊維の直径を測
定してその算術平均で示される値である。メルトブロー
不織布の単繊維の平均繊維径が大きくなると荷電効率が
低下する傾向があり、この平均繊維径が３μｍを越える
とその傾向は顕著になるのである。一方、平均繊維径が
小さくなるとメルトブロー不織布の充填密度が大きくな
りすぎ、圧力損失が高くなりすぎると言う問題が生じる
のである。つまり、単繊維の平均繊維径が０．５〜３μ
ｍで本発明で言う束状繊維が全繊維中に１０〜３０％含
まれるメルトブロー不織布のみがエレクトレットフィル
ターとした時に優れた濾過特性値を有するのである。In the above equation, E is the particle removal efficiency, and ΔP is the pressure loss. The average fiber diameter of the single fibers of the melt-blown nonwoven fabric in the present invention is preferably 0.5 to 3 μm. The average fiber diameter is a value indicated by an arithmetic average of the diameters of 100 or more single fibers arbitrarily measured. When the average fiber diameter of the single fibers of the melt-blown nonwoven fabric increases, the charging efficiency tends to decrease. When the average fiber diameter exceeds 3 μm, the tendency becomes remarkable. On the other hand, when the average fiber diameter is small, the filling density of the melt-blown nonwoven fabric becomes too large, and the problem that the pressure loss becomes too high occurs. That is, the average fiber diameter of the single fiber is 0.5 to 3 μm.
Only the melt-blown non-woven fabric containing 10 to 30% of the bundle fibers referred to in the present invention in all fibers has an excellent filtration characteristic value when used as an electret filter.
【００１０】本発明において、メルトブロー不織布の材
料にはポリプロピレン、ポリエチレン、α−ポリオレフ
ィン、ポリエステル、ポリカーボネート、テフロンポリ
弗化ビニリデン等の樹脂やそれらの混合物を用いること
ができる。本発明におけるメルトブロー不織布の製造条
件はノズル孔径０．１〜０．５ｍｍ、吐出量０．０２５
〜２．０ｇ／分. 孔、ノズル温度２００〜３００℃、牽
引空気温度２５０〜４００℃、牽引空気圧力０．２〜５
ｋｇ／ｃｍ2 、ノズル孔ピッチ０．５〜１０ｍｍ、ノズ
ルと繊維捕集コンベヤー間距離３０〜５００ｍｍが好ま
しい。中でも、ノズル孔ピッチ０．７〜１０ｍｍ、ノズ
ルと繊維捕集コンベヤー間距離６０〜２５０ｍｍがより
好ましい。本発明を次に実施例でもって詳細に説明す
る。In the present invention, a resin such as polypropylene, polyethylene, α-polyolefin, polyester, polycarbonate, Teflon polyvinylidene fluoride or a mixture thereof can be used as a material of the melt blown nonwoven fabric. The production conditions of the melt blown nonwoven fabric in the present invention are as follows: nozzle hole diameter: 0.1 to 0.5 mm;
~ 2.0g / min. Hole, nozzle temperature 200 ~ 300 ° C, traction air temperature 250 ~ 400 ° C, traction air pressure 0.2 ~ 5
kg / cm 2 , a nozzle hole pitch of 0.5 to 10 mm, and a distance between the nozzle and the fiber collecting conveyor of 30 to 500 mm are preferred. Among them, the nozzle hole pitch is more preferably 0.7 to 10 mm, and the distance between the nozzle and the fiber collecting conveyor is more preferably 60 to 250 mm. The present invention will now be described in detail with reference to examples.
【００１１】[0011]
実施例１〜３ アイソタクチックポリプロピレン（アタクテックポリプ
ロピレン含有量＝１．５％、ＭＦＩ＝３００、Ｍｗ／Ｍ
ｎ＝４．０）を用い、ノズル孔径０．２ｍｍ、吐出量
０．３ｇ／分. 孔、ノズル温度２８０℃、牽引空気温度
３３０℃、ノズル孔ピッチ１ｍｍの条件でノズルと繊維
捕集コンベヤー間距離をかえて溶融吹付けにより平均繊
維径２．１μｍのメルトブロー不織布（目付３０ｇ／ｍ
2 ）を作製した。次いで、アース電極上に半導体シート
を敷いてその上にメルトブロー不織布を置き、この上部
から１８ＫＶの直流印加電在を１０秒間かけてエレクト
レット化しフィルターとして用いた。表１にノズルと繊
維捕集コンベヤー間距離をかえたときの束上繊維を構成
する単繊維の本数で束状繊維の含有率の分布を示した。
表１における実施例１の電子顕微鏡写真を図１に実施例
２のそれを図２に示した。Examples 1-3 Isotactic polypropylene (Atactic polypropylene content = 1.5%, MFI = 300, Mw / M
n = 4.0), nozzle hole diameter 0.2 mm, discharge rate 0.3 g / min. hole, nozzle temperature 280 ° C., traction air temperature 330 ° C., nozzle hole pitch 1 mm, between nozzle and fiber collecting conveyor Melt blown nonwoven fabric having an average fiber diameter of 2.1 μm by melt spraying at different distances (30 g / m
2 ) was prepared. Next, a semiconductor sheet was laid on an earth electrode, and a melt-blown nonwoven fabric was placed thereon, and a DC applied potential of 18 KV was electretized from the upper portion over 10 seconds to be used as a filter. Table 1 shows the distribution of the content ratio of the bundled fibers according to the number of single fibers constituting the bundled fibers when the distance between the nozzle and the fiber collecting conveyor was changed.
An electron micrograph of Example 1 in Table 1 is shown in FIG. 1, and that of Example 2 is shown in FIG.
【００１２】次に、これら実施例および比較例につい
て、大気塵粒子（粒子直径０．３〜０．５μｍ）を用い
て通過風速５．３ｃｍ／秒でマノスターゲージで圧力損
失を、フィルターの上流と下流の大気塵粒子濃度から粒
子除去効率を測定した。この時に用いた計測器はレーザ
ーパーティクルカウンター（リオン製、ＫＣ−１４）で
ある。なお、実施例および比較例のエレクトレット化前
のメルトブロー不織布（非エレクトレットフィルター）
についても同様に粒子除去効率を測定した。結果を表２
に示した。表２において、本発明における束状繊維の含
有率が１０〜３０％の実施例１〜３の濾過特性値は比較
例１〜３に比べ明らかに高い値を示した。エレクトレッ
ト化前後の粒子除去効率Ｅ0 とＥから求めた濾過特性値
の比は実施例１〜３において１０以上と大で荷電効率の
高いことを示した。Next, for these Examples and Comparative Examples, the pressure loss was measured using a Manostar gauge at a passing air velocity of 5.3 cm / sec using atmospheric dust particles (particle diameter: 0.3 to 0.5 μm), and the pressure loss was measured upstream of the filter. And the particle removal efficiency was measured from the concentration of atmospheric dust particles downstream. The measuring instrument used at this time was a laser particle counter (manufactured by Rion, KC-14). In addition, the melt-blown non-woven fabric (non-electret filter) before the electretization of Examples and Comparative Examples
Similarly, the particle removal efficiency was measured. Table 2 shows the results
It was shown to. In Table 2, the filtration characteristic values of Examples 1 to 3 in which the content of the bundle fibers in the present invention is 10 to 30% were clearly higher than those of Comparative Examples 1 to 3. The ratio of the filtration characteristic values obtained from the particle removal efficiencies E 0 and E before and after electretization was as large as 10 or more in Examples 1 to 3, indicating that the charging efficiency was high.
【００１３】実施例４〜６ アイソタクチックポリプロピレン（アタクテックポリプ
ロピレン含有量＝１．８％、ＭＦＩ＝２００、Ｍｗ／Ｍ
ｎ＝６．０）を用い、ノズル孔径０．１５ｍｍ、ノズル
孔ピッチ１ｍｍ、ノズルと繊維捕集コンベヤー間距離１
３０ｍｍおよび表３に示す条件で融吹付けにより平均繊
維径の異なるメルトブロー不織布（目付３０ｇ／ｍ2 ）
を作製し、次いで、実施例１と同じ条件でエレクトレッ
ト化した。表３には実施例４〜６と比較例４〜５の溶融
吹付け条件と本発明における束状繊維の含有率、圧力損
失、粒子除去効率および濾過特性を示した。束状繊維の
含有率、圧力損失、粒子除去効率は実施例１と同じ方法
で測定した。実施例４〜６は泡過特性値が１．４以上と
大きな値を示すのに対し、平均繊維径が極めて細い比較
例４にあっては圧力損失が高くなるために濾過特性値と
しては低いものになってしまう。平均繊維径の大きい比
較例５は荷電効率が低いため粒子除去効率が小さくな
り、濾過特性値としては低いものになってしまう。Examples 4-6 Isotactic polypropylene (Atactic polypropylene content = 1.8%, MFI = 200, Mw / M
n = 6.0), the nozzle hole diameter is 0.15 mm, the nozzle hole pitch is 1 mm, and the distance between the nozzle and the fiber collecting conveyor is 1
Melt-blown non-woven fabrics having different average fiber diameters by melt spraying at 30 mm and under the conditions shown in Table 3 (30 g / m 2 basis weight)
Was prepared, and then electretized under the same conditions as in Example 1. Table 3 shows the melt spraying conditions of Examples 4 to 6 and Comparative Examples 4 to 5, and the content of bundled fibers, pressure loss, particle removal efficiency and filtration characteristics in the present invention. The content of bundled fibers, pressure loss, and particle removal efficiency were measured in the same manner as in Example 1. In Examples 4 to 6, the foaming characteristic value shows a large value of 1.4 or more, whereas in Comparative Example 4 in which the average fiber diameter is extremely small, the filtration loss is low because the pressure loss is high. It becomes something. Comparative Example 5, which has a large average fiber diameter, has a low charging efficiency, and therefore has a low particle removal efficiency, resulting in a low filtration characteristic value.
【００１４】[0014]
図１は実施例１におけるメルトブロー不織布の繊維の形
状の電子顕微鏡による断面写真、図２は実施例３におけ
るメルトブロー不織布の繊維の形状の電子顕微鏡による
断面写真である。FIG. 1 is a cross-sectional photograph of the fiber shape of the melt-blown nonwoven fabric in Example 1 by an electron microscope, and FIG. 2 is a cross-sectional photograph of the fiber shape of the melt-blown nonwoven fabric in Example 3 by an electron microscope.
【表１】 [Table 1]
【表２】 [Table 2]
【表３】 [Table 3]
Claims (1)
布における単繊維の平均繊維径が０．８〜３μｍであ
り、繊維の長手方向に部分的に並列的に融着してなる束
状繊維が全繊維中に１０〜３０％含まれてなることを特
徴とするエレクトレット繊維フィルター。An average fiber diameter of a single fiber in a melt-blown nonwoven fabric constituting a filter is 0.8 to 3 μm, and bundle fibers obtained by partially and parallel fusion in the longitudinal direction of the fiber are contained in all fibers. Electret fiber filter characterized by containing 10 to 30% by weight.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3201360A JP3013906B2 (en) | 1991-07-15 | 1991-07-15 | Electret fiber filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3201360A JP3013906B2 (en) | 1991-07-15 | 1991-07-15 | Electret fiber filter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0515717A JPH0515717A (en) | 1993-01-26 |
| JP3013906B2 true JP3013906B2 (en) | 2000-02-28 |
Family
ID=16439763
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3201360A Expired - Fee Related JP3013906B2 (en) | 1991-07-15 | 1991-07-15 | Electret fiber filter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3013906B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPWO2008035637A1 (en) * | 2006-09-22 | 2010-01-28 | 株式会社クラレ | Filter material and manufacturing method thereof |
| JP5813008B2 (en) | 2010-12-06 | 2015-11-17 | 三井化学株式会社 | Melt blown nonwoven fabric, manufacturing method and apparatus thereof |
| JP6614450B2 (en) * | 2016-05-11 | 2019-12-04 | パナソニックＩｐマネジメント株式会社 | Nonwoven fabric and sound absorbing material |
-
1991
- 1991-07-15 JP JP3201360A patent/JP3013906B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0515717A (en) | 1993-01-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101453591B1 (en) | Meltblown fiber web with staple fibers | |
| US7902096B2 (en) | Monocomponent monolayer meltblown web and meltblowing apparatus | |
| JP4955536B2 (en) | Aligned fiber web | |
| JP5747028B2 (en) | High loft spunbond web | |
| EP3237663B1 (en) | Melt spun filtration media for respiratory devices and face masks | |
| EP3332857B1 (en) | Air filter material, filter pack, and air filter unit | |
| US20100043639A1 (en) | Highly charged, charge stable nanofiber web | |
| AU2007356885B2 (en) | Highly charged, charge stable nanofiber web | |
| JP2006506551A (en) | Improved fiber nonwoven web | |
| KR20090040890A (en) | Molded monocomponent monolayer respirator with bimodal monolayer monocomponent media | |
| CA2670607C (en) | Abrasion resistant material for use in various media | |
| US20100326902A1 (en) | Laminated Filtration Media | |
| DE202007015994U1 (en) | Air filter medium | |
| EP3351671A1 (en) | Nonwoven fabric and air filter including same | |
| JP2019537503A (en) | Method for producing pleated textiles having electrostatically charged fibers and pleated textiles | |
| JPH07256026A (en) | Filter medium for air filter | |
| JP3013906B2 (en) | Electret fiber filter | |
| JPH11293555A (en) | Highly air-permeable nonwoven fabric and its production, and filter material made thereof | |
| JP3117713B2 (en) | Filament dispersion device | |
| WO2018030057A1 (en) | Nonwoven fabric and method for manufacturing same | |
| JPH0633571B2 (en) | Method for manufacturing electret nonwoven fabric | |
| JP3579738B2 (en) | Electret filter | |
| JP3578229B2 (en) | Fine particle filter media | |
| JP2001137630A (en) | Air cleaning filter | |
| JPH04163353A (en) | Nonwoven fabric of olefin-based ultra-fine fiber |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20071217 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081217 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081217 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091217 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091217 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101217 Year of fee payment: 11 |
|
| LAPS | Cancellation because of no payment of annual fees |