JP3660298B2 - Hydrophilic filter cloth - Google Patents
Hydrophilic filter cloth Download PDFInfo
- Publication number
- JP3660298B2 JP3660298B2 JP2001358008A JP2001358008A JP3660298B2 JP 3660298 B2 JP3660298 B2 JP 3660298B2 JP 2001358008 A JP2001358008 A JP 2001358008A JP 2001358008 A JP2001358008 A JP 2001358008A JP 3660298 B2 JP3660298 B2 JP 3660298B2
- Authority
- JP
- Japan
- Prior art keywords
- filter cloth
- cake
- treatment
- filter
- surface modification
- 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
Landscapes
- Filtering Materials (AREA)
- Chemical Or Physical Treatment Of Fibers (AREA)
- Woven Fabrics (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、耐目詰まり性、ケーキ剥離性に優れた固液分離用の濾過布に関する。
【０００２】
【従来の技術】
従来より固液分離用濾過布は、例えば製紙パルプの蒸解薬液回収工程、顔料製造工程、油脂精製工程、浄水場汚泥脱水工程等の固液分離装置に使用されており、その要求性能としては、高捕集性、耐目詰まり性、ケーキ剥離性、機械的強度・物理的化学的安定性、寸法安定性等が求められている。なかでも共通する問題点としては、濾過初期の濾過布の目詰まり又は濾過布上のケーキ薄層付着によるケーキ剥離困難による濾過サイクルの障害である。特に酸化チタン、黄鉛などの無機顔料、溶性アゾ顔料不溶アゾ顔料などの有機顔料等の顔料製造工程における固液分離用フィルタプレスにおいては、スラリー自体の粘性が高く、また濾過布自体が緻密で且つ高圧で濾過するためにケーキは密になりケーキ剥離も困難になり易い。そのため濾過布が早期に使用不能となり、その結果濾過布洗浄の頻度も多くなり多大の洗浄手間と時間がかかる問題点が指摘されている。
【０００３】
このような濾過布の汚れや目詰まり、ケーキ剥離困難を解決する方法として、従来から様々な試みがなされてきている。例えば、実開平７−２１１１４号公報では、ポリエステルマルチフィラメントによって製織された織物を親水化剤用液中に含浸することによって親水性を付与した酒もろみ濾過用フィルタークロスが開示されている。また実開昭５７−２８７２０号公報には、芯糸と被膜糸とのより糸からなり、被覆糸にグリシジルビニルモノマーをグラフト重合した後、亜硫酸塩もしくはチオ硫酸塩で処理したり、反応基含有接着樹脂を固着させる方法が開示されている。また特表２００１−５１１４８９号公報では、プラズマ放電処理された合成繊維またはヤーンを含有する層または組成部分を含む工業用ファブリック（抄紙機ファブリック、工業的ベルト、フイルタークロス、不織布、フイルム等）が開示されている。
【０００４】
【発明が解決しようとする課題】
しかしながら、上記実開平７−２１１１４号公報に記載の考案においては、経糸と緯糸を構成している繊維に親水性処理剤を付着させるものであるため、使用素材や使用工程、濾過物によっては早期に該親水性処理剤が脱落し、ケーキ剥離性の低下現象が問題視される。また上記実開昭５７−２８７２０号公報に記載の発明にあっては、親水性が十分ではなく、また被覆糸の親水化処理に複数の工程を必要とし手間がかかるデメリットがある。また上記特表２００１−５１１４８９号公報に記載の発明は、親水性を付与させるためにプラズマ放電処理を使用するので耐久親水性には優れるが、プラズマ放電処理設備が複雑かつ大掛かりなものであるため実用的でない。
【０００５】
そこで本発明は上記のような従来技術の問題点を改善し、実用的に、防汚性、耐目詰まり性、ケーキ剥離性に優れた固液分離用の濾過布を提供しようとするものである。
【０００６】
【課題を解決するための手段】
即ち本発明は、モノフィラメント糸、マルチフィラメント糸、紡績糸から選択され得る合成樹脂繊維材料から成る経糸と緯糸が製織されて成るベルト型フィルタ、ディスク型フィルタ、水平ベルト型フィルタ、フイルタプレス、ベルトプレス型脱水機の固液分離工程に使用される固液分離用濾過布であって、該繊維材料及び／又は該濾過布の表面改質処理により親水性の官能基が付与され、表面改質処理された濾過布表面が、エネルギー分散形蛍光Ｘ線分析法にて測定した炭素に対する酸素の元素組成比（Ｏ／Ｃ）値が０．０２〜０．２０であることを特徴とする親水性を有するケーキ剥離性濾過布をもって、上記課題を解決するものである。また該表面改質処理が、コロナ放電処理又はオゾンガス処理による親水性付与処理であることが好ましい。また該繊維材料がポリオレフイン系樹脂から成ることが好ましい。
【０００７】
【発明の実施の形態】
本発明の親水性濾過布は、例えば、ベルト型フィルタ、ディスク型フィルタ、水平ベルト型フィルタ、フイルタプレス、ベルトプレス型脱水機等の固液分離工程に使用される固液分離用濾過布であって、該濾過布に親水性の官能基を付与することにより、ケーキに対する液ぬれ性を高めることによって、防汚性、耐目詰まり性、ケーキの剥離性を向上させた親水性濾過布である。以下に具体的にその実施形態を例示する。
【０００８】
本発明の親水性濾過布は、例えばモノフィラメント糸、マルチフィラメント糸、紡績糸のいずれかから選択され得る合成樹脂繊維材料から成る経糸と緯糸を織成されたプラスチック織物から構成される。該プラスチック織物を各濾過機の仕様に応じて形態加工することにより濾過布として使用される。またモノフィラメント糸、マルチフィラメント糸、紡績糸のいずれを採用するかは、濾過布に対して要求される性能に応じて適宜選択すればよい。例えば、前記顔料製造工程では製品が高価であるため捕集効率を優先して紡績糸やマルチフィラメント糸使いが好ましい。また前記油脂精製工程では高温下での寸法安定性、耐目詰まり性、濾液清澄性などの条件を考慮してマルチフィラメント糸が好ましい。また前記浄水場汚泥脱水工程では、強度、ケーキ剥離性に優れ且つ洗浄再現性を考慮してモノフィラメント糸使いが好ましい。もちろん濾過布が配設される濾過機タイプや使用素材にもよる。またこれらの各糸を組み合わせて使用してもよいことは言うまでもない。
【０００９】
また前記表面改質処理は、前記繊維材料自体を予め表面改質処理してもよく、また織成後に濾過布全体を表面改質処理してもよい。また製織前後で繊維材料と濾過布とのそれぞれの段階で表面改質処理してもよい。いずれにしても濾過布表面に親水性の官能基を付与するための処理であって特に限定するものではないが、表面改質効率からすれば織成後に濾過布全体を処理することが効率的で好ましい。しかしながら、特に広幅の濾過布など表面改質装置幅を越える場合などは、繊維材料段階で予め表面改質処理しておいた後に製織することが好ましい。また前記表面改質処理前及び／又は後に親水性繊維処理剤を繊維材料表面又は濾過布表面に付与してもよい。工程性、親水性能付与の効率化などを考慮すると表面改質後に該繊維処理剤を付与させることが好ましい。該親水性繊維処理剤としては、例えばアルキルリン酸エステルなどのリン酸系アニオン活性剤、脂肪族カルボン酸石けんなどの石けん系アニオン活性剤、アルキルサルフェートなどのサルフェート系アニオン活性剤、ポリエチレングリコール等を使用することができ、これらを２種以上混合してもよい。該繊維処理剤は繊維重量に対して０．１〜１．０質量％繊維材料表面に付与させることが好ましい。付与方法としては、浸せき法、スプレー法、コーティング法の何れでもよい。繊維処理剤の付与量が０．１質量％未満であると初期の親水性が不十分であり、１．０質量％より大きいと不経済である。
【００１０】
上記表面改質処理にはコロナ放電処理及び／又はオゾンガス処理が好ましい。該コロナ放電処理やオゾンガス処理は公知の方法が採用し得る。例えば、表面改質処理をコロナ放電処理で実施する場合、コロナ放電処理における１回当たりの放電量は、少なくとも５０W/m2/minであることが好ましく総放電量は１００〜５０００W/m2/minであることが好ましい。より好ましい放電量は、２５０〜５０００W/m2/minである。放電量が５０W/m2/min未満、あるいは総放電量が１００W/m2/min未満であると、濾過布に付与する酸素元素量が不十分となり、５０００W/m2/minを超えると、過剰処理となり高コストであるとともに繊維表面の劣化が生じ易くなり、濾過布強力にも影響を与える。またオゾンガス処理で実施する場合は、オゾンガスと酸素ガスとの混合ガスを使用して処理される。このときの混合ガス中のオゾンガス濃度は１万〜５０万ｐｐｍであり、より好ましくは５万〜３０万ｐｐｍである。また該オゾンガス処理の処理温度は５０℃以上、好ましくは８０〜１７０℃、更に好ましくは１００〜１５０℃である。こうした表面改質処理により、繊維材料や濾過布表面に親水性の官能基が導入され親水性を付与することが可能となる。例えばポリオレフィン系樹脂繊維の場合、−ＣＨＯ−、−ＣＯ−、−ＣＯＯ−等の官能基が挙げられる。もちろん合成樹脂繊維材料や繊維集合体の表面改質による親水化処理には他にもプラズマ放電処理やフッ素ガス処理等が公知であるが、設備的に大がかりであり投資コストが大となる難点があり、また繊維材料へのダメージによる繊維強力の低下などを考慮すれば、前記コロナ放電処理やオゾンガス処理が実用的である。
【００１１】
表面改質処理された濾過布表面に親水性の官能基が付与されたかどうかは、例えばエネルギー分散形蛍光Ｘ線分析法にて確認することが可能である。本発明においては、該エネルギー分散形蛍光Ｘ線分析法にて測定した炭素に対する酸素の元素組成比（Ｏ／Ｃ）値が０．０２〜０．２であることが好ましい。より好ましくは該（Ｏ／Ｃ）値が０．０２５〜０．０５である。該（Ｏ／Ｃ）値が０．０２未満であると十分な親水性が得られないために、目的とする良好な耐目詰まり性やケーキ剥離性が得られなくなる。逆に該（Ｏ／Ｃ）値が０．２０を越えても親水性の効果がそれほど向上することはなく不経済である。むしろコロナ放電量を高めることによる生産効率の低下や繊維劣化を引き起こす恐れがあり濾過布強度を考慮すれば好ましくない。
【００１２】
また繊維材料としては、繊維形成能のある熱可塑性樹脂であればよいが、ポリプロピレン、ポリエチレン、ポリメチルペンテンなどのポリオレフィン系樹脂、ポリエチレンテレフタレート、ポリブチレンテレフタレートなどのポリエステル系樹脂が好ましい。特に顔料製造工程や浄水場汚泥脱水工程においては、耐酸性、耐アルカリ性等の耐化学薬品性が求められるため、ポリオレフィン系樹脂が好ましく、より好ましくはポリプロピレン樹脂である。
【００１３】
また、上記表面改質処理により、ケーキ剥離後の濾過布へのケーキ付着率が４．０質量％以下とすることが好ましい。該ケーキ付着率が４．０質量％を越えると、目詰まりが起こりやすく、濾過圧不足やケーキ剥離困難による濾過サイクルの障害、生産性の悪化につながるので好ましくない。
【００１４】
【実施例】
本発明の親水性濾過布について以下の実施例にてより具体的に説明する。もちろん本発明が本実施例に限定されるものではない。尚、本実施例における（Ｏ／Ｃ）値、ケーキ剥離強度、ケーキ付着率、ケーキ剥離性能持続度は下記のようにして測定したものである。
【００１５】
［Ｏ／Ｃ値］
エネルギー分散形蛍光Ｘ線分析装置（装置名：Ｅ−Ｍａｘ−７０００、堀場製作所製）、電界放出形走査電子顕微鏡（装置名：Ｓ−４７００、日立製作所製）を使用して、加速電圧１０ｋＶ、印加電流１０μＡ、観測倍率２５０倍、測定時間１００秒の条件下で測定し、そのときに測定されたＯ元素量をＣ元素量で割り返した値を（Ｏ／Ｃ）値とした。
【００１６】
［ケーキの剥離強度］
（タテ：１５ｃｍ）×（ヨコ：７．５ｃｍ）の濾過布サンプル２枚採取し、測定で使用するスラリーはアゾ系顔料（大日精化工業製、ＺＡ６６５レッドＣ３０３−６２８ＣＯ）１１０ｇにエチルアルコール（和光純薬工業製）５５ｍｌと蒸留水１６５ｍｌを加え練り混ぜることで調製した。次いで６ｃｍ×２０ｃｍの木枠（商品名：F−３８中、曽南製）の下部に上記で採取した試料を表面が上になるように一枚敷き、その上に上記で調製したスラリーを流し込み、スラリーの表面を平滑に慣らした後にもう一枚の試料を表面が下になるように載置した。その後に木枠の木型をセットし油圧プレスで５ｋｇ／ｃｍ2となるように加圧し、３０分間放置した後、木枠から試料と加圧により脱水されたケーキを取り出し、取り出し後、上方に載置されている試料の一端を定速伸長型引張試験機（装置名：テンシロンＵＣＴ−１Ｔ、オリエンテック製）によって引張速度１０ｃｍ／分で引張り、そのときの応力を剥離強度とした。
【００１７】
［ケーキ付着率］
上記の剥離強度試験でケーキから剥離した試料を１０５℃で２時間乾燥し、その後下記式によってケーキ付着率（％）を算出した。
（試料の自体の重量：Ｗ１、ケーキから剥離した試料の重量Ｗ２とする）
ケーキ付着率（％）＝｛（ Ｗ２−Ｗ１）／Ｗ１｝×１００
【００１８】
［ケーキ剥離性能持続度］
上記の剥離強度試験とケーキ付着率測定を繰り返し行い、ケーキ付着率が４．０質量％を越えたときの剥離試験回数をケーキ剥離性能持続度とした。
【００１９】
［実施例１］
経糸として繊度８８０ｄｔｅｘのポリプロピレンマルチフィラメント糸を使用、緯糸として繊度５６１ｄｔｅｘのポリプロピレンマルチフィラメントを二本撚りしたマルチフィラメント双糸を使用し、経糸密度を７３．５本／インチ、緯糸密度を３４本／インチとして、２／２綾織組織で製織し、目付４９０ｇ／ｍ2 の濾過布基布を準備し、該濾過布基布を室温２５℃の雰囲気下でコロナ放電処理機を通し、両面にそれぞれ放電量１０２６W/m2/minを与えて濾過布表裏面に各々コロナ放電処理を施して本発明の親水性濾過布を得た。こうした表面改質処理によって親水化処理された本発明の親水性濾過布は、（Ｏ／Ｃ）値が０．０３２、ケーキ剥離強度が０．３６Ｎ、ケーキ付着率が３．０％、ケーキ剥離性持続度が３０回であり、良好なケーキ剥離性やケーキの剥離性能の持続性も有していることが確認された。また目視で耐目詰まり性も良好であることが確認された。
【００２０】
尚、本実施例ではオゾンガス処理については例示しないが、コロナ放電処理と同様に処理すればよい。例えば、処理温度１５０℃、オゾンガス濃度７万ｐｐｍのオゾンガスと酸素ガスの混合ガス雰囲気下にて濾過布を２０秒間オゾンガス処理を施し、表面改質処理することにより本発明の親水性濾過布が得られる。
【００２１】
［実施例２］
経糸、緯糸に繊度８８０ｄｔｅｘのポリプロピレンマルチフィラメントを二本撚りしたマルチフィラメント双糸を使用し、経糸密度を５６本／インチ、緯糸密度を１８．５本／インチとして、平織織組織で製織し、目付６３０ｇ／ｍ2 の濾過布基布を準備し、実施例１と同様に表面改質処理した。得られた親水性濾過布は、（Ｏ／Ｃ）値が０．０３１、ケーキ剥離強度が０．３９Ｎ、ケーキ付着率が３．１％、ケーキ剥離性持続度が２９回であり、良好なケーキ剥離性やケーキの剥離性能の持続性も有していることが確認された。また目視で耐目詰まり性も良好であることが確認された。
【００２２】
［比較例１］
実施例1において親水化処理をしなかった以外は実施例1と同様にして濾過布を得た。得られた濾過布は、（Ｏ／Ｃ）値が０、ケーキ剥離強度が０．５４Ｎ、ケーキ付着率が６．５％、ケーキ剥離性持続度が０回であり、ケーキ剥離性が悪く且つ目詰まりを起こしていた。
【００２３】
［比較例２］
実施例１においてコロナ放電処理をせず、濾過布に親水化処理剤としてポリエテレングリコールを０．２質量％濾過布に塗布した以外は同様にして濾過布を得た。得られた濾過布は、（Ｏ／Ｃ）値が０．０２９、ケーキ剥離強度が０．４０Ｎ、ケーキ付着率が３．５％、ケーキ剥離性持続度が２回であり、ケーキの剥離性能の持続性は有していなかった。
【００２４】
【発明の効果】
本発明の親水性濾過布は、表面改質処理によりその表面に親水性の官能基が付与されているため液ぬれ性に優れ、ケーキ剥離性が良好で、また濾過布の目詰まりも低減されるため、ケーキ剥離困難による濾過サイクルの障害の低減を図る事が出来る。特にスラリーの粘性が高い顔料製造工程や浄水場汚泥脱水工程の固液分離用濾過布に好適である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a filter cloth for solid-liquid separation having excellent clogging resistance and cake peelability.
[0002]
[Prior art]
Conventionally, the filter cloth for solid-liquid separation has been used in solid-liquid separation devices such as the pulp chemical cooking chemical recovery process, pigment production process, oil refining process, water purification plant sludge dehydration process, etc. High collection property, clogging resistance, cake peelability, mechanical strength / physical chemical stability, dimensional stability, etc. are required. Among them, a common problem is a clogging of the filter cloth at the initial stage of filtration or an obstacle to the filtration cycle due to difficulty in peeling the cake due to adhesion of a cake thin layer on the filter cloth. Especially in solid-liquid separation filter presses in pigment manufacturing processes such as inorganic pigments such as titanium oxide and yellow lead, organic pigments such as soluble azo pigments and insoluble azo pigments, the slurry itself has a high viscosity and the filter cloth itself is dense. In addition, since the cake is filtered at a high pressure, the cake becomes dense and the cake peeling tends to be difficult. Therefore, the filter cloth becomes unusable at an early stage, and as a result, the frequency of cleaning the filter cloth is increased, and it has been pointed out that it takes much time and labor.
[0003]
Various attempts have been made in the past as a method for solving such dirt and clogging of the filter cloth and difficulty in peeling the cake. For example, Japanese Utility Model Laid-Open No. 7-21114 discloses a filter cloth for filtration of sake mash by imparting hydrophilicity by impregnating a fabric woven with polyester multifilament into a liquid for hydrophilizing agent. Japanese Utility Model Laid-Open No. 57-28720 includes a twisted yarn of a core yarn and a coated yarn. After graft polymerization of a glycidyl vinyl monomer on the coated yarn, treatment with sulfite or thiosulfate, or reactive group-containing adhesion A method for fixing a resin is disclosed. JP-T-2001-511489 discloses an industrial fabric (a paper machine fabric, an industrial belt, a filter cloth, a nonwoven fabric, a film, etc.) including a layer or a composition part containing a synthetic fiber or yarn subjected to plasma discharge treatment. Has been.
[0004]
[Problems to be solved by the invention]
However, in the device described in the above-mentioned Japanese Utility Model Publication No. 7-21114, a hydrophilic treatment agent is attached to the fibers constituting the warp and the weft. In addition, the hydrophilic treatment agent falls off, and the phenomenon that the cake peelability is lowered is regarded as a problem. In the invention described in Japanese Utility Model Publication No. 57-28720, there is a demerit that the hydrophilicity is not sufficient, and that a plurality of steps are required for the hydrophilic treatment of the coated yarn. In addition, the invention described in the above Japanese Patent Publication No. 2001-511489 uses plasma discharge treatment for imparting hydrophilicity and is excellent in durability and hydrophilicity, but the plasma discharge treatment equipment is complicated and large-scale. Not practical.
[0005]
Accordingly, the present invention aims to provide a filter cloth for solid-liquid separation that improves the above-mentioned problems of the prior art and is practically excellent in antifouling property, clogging resistance and cake peelability. is there.
[0006]
[Means for Solving the Problems]
That is, the present invention relates to a belt type filter, a disk type filter, a horizontal belt type filter, a filter press, a belt press formed by weaving warp and weft made of a synthetic resin fiber material that can be selected from monofilament yarn, multifilament yarn, and spun yarn. A filter cloth for solid-liquid separation used in a solid-liquid separation process of a mold dehydrator , wherein a hydrophilic functional group is imparted by surface modification treatment of the fiber material and / or the filter cloth, and the surface modification treatment The surface of the filter cloth is hydrophilic, characterized in that the elemental composition ratio (O / C) value of oxygen to carbon measured by energy dispersive X-ray fluorescence analysis is 0.02 to 0.20. The above-mentioned problem is solved with the cake peelable filter cloth . Further, the surface modification treatment is preferably a hydrophilicity imparting treatment by corona discharge treatment or ozone gas treatment. The fiber material is preferably made of a polyolefin resin.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The hydrophilic filter cloth of the present invention is, for example, a filter cloth for solid-liquid separation used in a solid-liquid separation process such as a belt-type filter, a disk-type filter, a horizontal belt-type filter, a filter press, and a belt press-type dehydrator. In addition, by adding a hydrophilic functional group to the filter cloth, it is a hydrophilic filter cloth that has improved anti-fouling properties, clogging resistance, and peelability of the cake by enhancing the wettability to the cake. . The embodiment is specifically illustrated below.
[0008]
The hydrophilic filter cloth of the present invention is composed of a plastic fabric in which warps and wefts made of a synthetic resin fiber material that can be selected from, for example, monofilament yarn, multifilament yarn, and spun yarn are woven. The plastic fabric is used as a filter cloth by processing the shape according to the specifications of each filter. Whether monofilament yarn, multifilament yarn or spun yarn is used may be appropriately selected according to the performance required for the filter cloth. For example, since the product is expensive in the pigment production process, it is preferable to use spun yarn or multifilament yarn in order to prioritize collection efficiency. In the oil and fat refining step, a multifilament yarn is preferable in consideration of conditions such as dimensional stability at high temperature, clogging resistance, and filtrate clarification. In the water purification plant sludge dewatering step, it is preferable to use monofilament yarn in consideration of strength, cake peelability and washing reproducibility. Of course, it depends on the filter type and the material used. Needless to say, these yarns may be used in combination.
[0009]
In the surface modification treatment, the fiber material itself may be subjected to surface modification treatment in advance, or the entire filter cloth may be subjected to surface modification treatment after weaving. Further, surface modification treatment may be performed at each stage of the fiber material and the filter cloth before and after weaving. In any case, it is a treatment for imparting a hydrophilic functional group to the surface of the filter cloth and is not particularly limited. However, in terms of surface modification efficiency, it is efficient to treat the entire filter cloth after weaving. Is preferable. However, in particular, when the width of the surface modification device is exceeded, such as a wide filter cloth, it is preferable to perform weaving after surface modification treatment in advance in the fiber material stage. Further, before and / or after the surface modification treatment, a hydrophilic fiber treatment agent may be applied to the surface of the fiber material or the surface of the filter cloth. In consideration of processability and efficiency of imparting hydrophilic performance, it is preferable to apply the fiber treatment agent after surface modification. Examples of the hydrophilic fiber treating agent include phosphate anion activators such as alkyl phosphate esters, soap anion activators such as aliphatic carboxylate soaps, sulfate anion activators such as alkyl sulfates, polyethylene glycol and the like. These may be used, and two or more of these may be mixed. The fiber treatment agent is preferably added to the surface of the fiber material in an amount of 0.1 to 1.0% by mass with respect to the fiber weight. As an application method, any of a dipping method, a spray method, and a coating method may be used. If the applied amount of the fiber treatment agent is less than 0.1% by mass, the initial hydrophilicity is insufficient, and if it is greater than 1.0% by mass, it is uneconomical.
[0010]
The surface modification treatment is preferably a corona discharge treatment and / or an ozone gas treatment. A known method can be employed for the corona discharge treatment or the ozone gas treatment. For example, when performing surface modification treatment by corona discharge treatment, discharge amount per one of corona discharge treatment, it is preferable the total amount of discharge of at least 50W / m 2 / min 100~5000W / m 2 / Preferably it is min. A more preferable discharge amount is 250 to 5000 W / m 2 / min. If the discharge amount is less than 50 W / m 2 / min, or the total discharge amount is less than 100 W / m 2 / min, the amount of oxygen element applied to the filter cloth becomes insufficient, and if it exceeds 5000 W / m 2 / min, This is an excessive treatment and is expensive, and the fiber surface is liable to be deteriorated, affecting the strength of the filter cloth. Moreover, when implementing by ozone gas processing, it processes using the mixed gas of ozone gas and oxygen gas. The ozone gas concentration in the mixed gas at this time is 10,000 to 500,000 ppm, more preferably 50,000 to 300,000 ppm. The treatment temperature for the ozone gas treatment is 50 ° C. or higher, preferably 80 to 170 ° C., more preferably 100 to 150 ° C. By such surface modification treatment, hydrophilic functional groups can be introduced to the fiber material or the filter cloth surface to impart hydrophilicity. For example, in the case of polyolefin resin fibers, functional groups such as —CHO—, —CO—, and —COO— can be mentioned. Of course, plasma discharge treatment, fluorine gas treatment, etc. are well known for hydrophilic treatment by surface modification of synthetic resin fiber materials and fiber aggregates, but there is a problem that the equipment is large and the investment cost is high. In view of the decrease in fiber strength due to damage to the fiber material, the corona discharge treatment and ozone gas treatment are practical.
[0011]
Whether or not a hydrophilic functional group has been imparted to the surface of the filter cloth subjected to the surface modification treatment can be confirmed by, for example, energy dispersive X-ray fluorescence analysis. In the present invention, the elemental composition ratio (O / C) value of oxygen to carbon measured by the energy dispersive X-ray fluorescence analysis method is preferably 0.02 to 0.2. More preferably, the (O / C) value is 0.025 to 0.05. If the (O / C) value is less than 0.02, sufficient hydrophilicity cannot be obtained, so that the desired good clogging resistance and cake peelability cannot be obtained. Conversely, even if the (O / C) value exceeds 0.20, the hydrophilic effect is not improved so much, which is uneconomical. Rather, increasing the corona discharge amount may cause a decrease in production efficiency and fiber deterioration, which is not preferable in consideration of the strength of the filter cloth.
[0012]
The fiber material may be any thermoplastic resin capable of forming fibers, but is preferably a polyolefin resin such as polypropylene, polyethylene or polymethylpentene, or a polyester resin such as polyethylene terephthalate or polybutylene terephthalate. Particularly in the pigment production process and the water purification plant sludge dehydration process, chemical resistance such as acid resistance and alkali resistance is required, and therefore, a polyolefin resin is preferable, and a polypropylene resin is more preferable.
[0013]
Moreover, it is preferable that the cake adhesion rate to the filter cloth after cake peeling shall be 4.0 mass% or less by the said surface modification process. If the cake adhesion rate exceeds 4.0% by mass, clogging is likely to occur, which is not preferable because it leads to a filtration cycle failure due to insufficient filtration pressure, difficulty in peeling the cake, and deterioration of productivity.
[0014]
【Example】
The hydrophilic filter cloth of the present invention will be described more specifically in the following examples. Of course, the present invention is not limited to this embodiment. In addition, the (O / C) value, cake peeling strength, cake adhesion rate, and cake peeling performance duration in this example were measured as follows.
[0015]
[O / C value]
Using an energy dispersive X-ray fluorescence analyzer (device name: E-Max-7000, manufactured by Horiba, Ltd.) and a field emission scanning electron microscope (device name: S-4700, manufactured by Hitachi, Ltd.), an acceleration voltage of 10 kV, Measurement was performed under the conditions of an applied current of 10 μA, an observation magnification of 250 times, and a measurement time of 100 seconds, and a value obtained by dividing the O element amount measured at that time by the C element amount was defined as an (O / C) value.
[0016]
[Cake peel strength]
(Vertical: 15 cm) x (horizontal: 7.5 cm) 2 filter cloth samples were collected, and the slurry used in the measurement was 110 g of azo pigment (Za665 Red C303-628CO, manufactured by Dainichi Seika Kogyo Co., Ltd.) and ethyl alcohol (Japanese It was prepared by adding and kneading 55 ml of Koyo Pure Chemical Industries) and 165 ml of distilled water. Next, a sample of the above sample is laid on the bottom of a 6 cm × 20 cm wooden frame (trade name: manufactured by Shonan in F-38), and the slurry prepared above is poured thereon. After the surface of the slurry was acclimated smoothly, another sample was placed with the surface facing down. After that, set the wooden frame of the wooden frame and pressurize it to 5 kg / cm 2 with a hydraulic press, leave it for 30 minutes, take out the sample and the cake dehydrated by pressurization from the wooden frame, and take it out upward One end of the placed sample was pulled at a tensile speed of 10 cm / min with a constant speed extension type tensile tester (device name: Tensilon UCT-1T, manufactured by Orientec), and the stress at that time was defined as peel strength.
[0017]
[Cake attachment rate]
The sample peeled from the cake in the peel strength test was dried at 105 ° C. for 2 hours, and then the cake adhesion rate (%) was calculated by the following formula.
(The weight of the sample itself: W1, the weight W2 of the sample peeled from the cake)
Cake adhesion rate (%) = {(W2-W1) / W1} × 100
[0018]
[Cake peeling performance duration]
The above peeling strength test and cake adhesion rate measurement were repeated, and the number of peeling tests when the cake adhesion rate exceeded 4.0% by mass was defined as the cake peeling performance duration.
[0019]
[Example 1]
Polypropylene multifilament yarn with a fineness of 880 dtex is used as the warp, and multifilament twin yarn in which two polypropylene multifilaments with a fineness of 561 dtex are used as the weft, the warp density is 73.5 / inch, and the weft density is 34 / inch. Weaving with a 2/2 twill structure, preparing a filter cloth base fabric with a basis weight of 490 g / m 2 , passing the filter cloth base fabric through a corona discharge treatment machine in an atmosphere at room temperature of 25 ° C. A hydrophilic filter cloth of the present invention was obtained by applying corona discharge treatment to the front and back surfaces of the filter cloth at 1026 W / m 2 / min. The hydrophilic filter cloth of the present invention hydrophilized by such surface modification treatment has an (O / C) value of 0.032, a cake peel strength of 0.36 N, a cake adhesion rate of 3.0%, and a cake peel. The durability was 30 times, and it was confirmed that the cake has good cake peelability and sustainability of cake peelability. Moreover, it was confirmed visually that clogging resistance was also good.
[0020]
In addition, although an ozone gas process is not illustrated in a present Example, what is necessary is just to process similarly to a corona discharge process. For example, the hydrophilic filter cloth of the present invention can be obtained by subjecting the filter cloth to ozone gas treatment for 20 seconds in a mixed gas atmosphere of ozone gas and oxygen gas having a treatment temperature of 150 ° C. and an ozone gas concentration of 70,000 ppm, and then subjecting it to surface modification treatment. It is done.
[0021]
[Example 2]
Weaving a plain weave fabric with a warp density of 56 yarns / inch and a weft density of 18.5 yarns / inch, using a multifilament twine twisted with 880 dtex polypropylene multifilaments for warp and weft. A filter cloth base fabric of 630 g / m 2 was prepared and surface-modified as in Example 1. The obtained hydrophilic filter cloth had an (O / C) value of 0.031, a cake peel strength of 0.39 N, a cake adhesion rate of 3.1%, and a cake peelability persistence of 29 times. It was confirmed that the cake peelability and the cake peelability were also sustained. Moreover, it was confirmed visually that clogging resistance was also good.
[0022]
[Comparative Example 1]
A filter cloth was obtained in the same manner as in Example 1 except that the hydrophilization treatment was not performed in Example 1. The obtained filter cloth had an (O / C) value of 0, cake peel strength of 0.54 N, cake adhesion rate of 6.5%, cake peelability persistence of 0, and cake peelability was poor. It was clogging.
[0023]
[Comparative Example 2]
A filter cloth was obtained in the same manner as in Example 1 except that the corona discharge treatment was not performed and polyethylene glycol was applied to the filter cloth as a hydrophilic treatment agent on 0.2% by mass of the filter cloth. The obtained filter cloth has an (O / C) value of 0.029, a cake peel strength of 0.40 N, a cake adhesion rate of 3.5%, and a cake peelability persistence of 2 times. There was no persistence.
[0024]
【The invention's effect】
The hydrophilic filter cloth of the present invention is provided with a hydrophilic functional group on the surface by the surface modification treatment, so that the liquid wettability is excellent, the cake peelability is good, and the clogging of the filter cloth is also reduced. Therefore, it is possible to reduce the failure of the filtration cycle due to difficulty in peeling the cake. Particularly, it is suitable for a filter cloth for solid-liquid separation in a pigment manufacturing process or a water purification plant sludge dewatering process in which the viscosity of the slurry is high.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001358008A JP3660298B2 (en) | 2001-11-22 | 2001-11-22 | Hydrophilic filter cloth |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001358008A JP3660298B2 (en) | 2001-11-22 | 2001-11-22 | Hydrophilic filter cloth |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003154221A JP2003154221A (en) | 2003-05-27 |
| JP3660298B2 true JP3660298B2 (en) | 2005-06-15 |
Family
ID=19169262
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001358008A Expired - Fee Related JP3660298B2 (en) | 2001-11-22 | 2001-11-22 | Hydrophilic filter cloth |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3660298B2 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008279339A (en) * | 2007-05-09 | 2008-11-20 | Jfe Engineering Kk | Solid/liquid separation apparatus |
| CN104514069B (en) * | 2014-11-27 | 2016-10-05 | 安徽省太和县众友筛网滤布制造有限公司 | A kind of high temperature resistant industrial filter cloth production technology |
| CN104514070A (en) * | 2014-11-27 | 2015-04-15 | 安徽太平洋特种网业有限公司 | Production technology for polyester quick separation net fabric |
| CN104511209A (en) * | 2014-11-27 | 2015-04-15 | 安徽省太和县众友筛网滤布制造有限公司 | Industrial filter cloth production process |
| JP6807574B2 (en) * | 2016-11-02 | 2021-01-06 | 株式会社片山化学工業研究所 | An agent for improving the peelability of a cake from the filter cloth of a squeezing dehydrator using a filter cloth and a method for peeling the cake using the agent. |
| JP7193326B2 (en) * | 2018-12-07 | 2022-12-20 | 月島機械株式会社 | Solid-liquid separator and filtration device |
| US20240228832A9 (en) * | 2022-10-21 | 2024-07-11 | Ching Shui HSU | Polypropylene fabric and fabric treating method |
-
2001
- 2001-11-22 JP JP2001358008A patent/JP3660298B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2003154221A (en) | 2003-05-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE69411632T2 (en) | Filter material and process for its manufacture | |
| DE69717704T2 (en) | Absorbent and dust collecting device | |
| JP3660298B2 (en) | Hydrophilic filter cloth | |
| CA1171214A (en) | Set polyacrylonitrile filaments and fibers, and a process for their production | |
| Sun et al. | Facile fabrication of hydrophilic-underwater superoleophobic poly (N-isopropylacrylamide) coated PP/LPET nonwoven fabrics for highly efficient oil/water separation | |
| DE2318831B2 (en) | Use of microfiber aggregates made from synthetic polymers as adsorbents | |
| EP2220276A2 (en) | A nonwoven for air filtration and a preparation method thereof | |
| CN1760002A (en) | Method for preparing rush pith sheet material and the rush pith sheet material with antibiotic and odor eliminating properties | |
| EP0875608B1 (en) | Conveyor belt for transport belts having elastic yarns, use, method for transporting goods and device | |
| DE60223714T2 (en) | PROCESS FOR PREPARING POLYPROPYLENE MONOFILAMENTS, POLYPROPYLENE MONOFILAMENTS, AND THEIR USE | |
| JP3827962B2 (en) | Method for producing ultrafine fiber nonwoven fabric | |
| DE19817160A1 (en) | Process for recycling polyamide material containing silicone resin | |
| WO2019076823A1 (en) | Process for producing a textile article having a water-repellent textile surface by plasma treatment and wet-chemical treatment | |
| DE2806688C2 (en) | ||
| DE2831601A1 (en) | TEXTILE FLORAL PRODUCTS WITH A PILOT BLANKET MADE OF EXTREMELY FINE ACRYLIC POLYMER FIBERS AND THE METHOD OF MANUFACTURING IT | |
| DE60207361T2 (en) | WATER-VAPOR-PERMEABLE AND WATER-PROOF COMPOSITE FABRIC, THIS INCLUDING WATER-PROOF SUBSTANCE AND METHOD OF MANUFACTURING THEREOF | |
| DE102006042635A1 (en) | Textile product and process for its preparation | |
| JP4298186B2 (en) | Method for producing ultra-thin fiber nonwoven fabric | |
| DE102007041259A1 (en) | Finishing textile fabrics, useful in e.g. geotextiles and technical textiles, comprises finishing textile fabrics with a composition comprising an organosiloxanylacrylate compound, and hardening the composition applied on textile fabrics | |
| CA2313213A1 (en) | Reactive fiber-like cellulose coagulates | |
| DE2835293B2 (en) | Process for the production of leather-like flat materials | |
| CN110253984A (en) | A kind of electrostatic spinning nano fiber film-fabric composite coating material and preparation method | |
| JP4316783B2 (en) | Manufacturing method of long fiber nonwoven fabric | |
| DE3619033A1 (en) | METHOD FOR PRODUCING FLOCK | |
| JP2916234B2 (en) | Wiping cloth |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20041116 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20041124 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20050120 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20050315 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20050316 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090325 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090325 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100325 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110325 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110325 Year of fee payment: 6 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110325 Year of fee payment: 6 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110325 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120325 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120325 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130325 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130325 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140325 Year of fee payment: 9 |
|
| LAPS | Cancellation because of no payment of annual fees |