【０００１】
【発明の属する技術分野】
本発明は流体中の固体を分離するための合成樹脂製多孔質薄膜を貫通柱状支持体に接合したスパイラル型フィルタエレメントに関する。
【０００２】
【従来の技術】
これまでも、例えばスパイラル型フィルタエレメントは種々提案されてきており、多孔質薄膜袋状濾材の開口部を、本願における支持体の一つである内部流路を有しこれに連通し軸方向に延伸する開口部を有する流体通路管に接合する方法が提案されてきた。さらに、特開平９−３１３８９８号においては、封筒状の濾材をそのまま延伸し多角形断面を有する集液管とも呼ばれる流体通路管の一縁に沿った状態に配置して接合する改善方法が提案されている。
【０００３】
しかしながらこのような改善方法が提案されても上記のような接合場面においては多角形断面を有する支持体ではなく、切削、材料手配その他の作成上の理由からも円柱状の支持体を採用したいことが多いこと、スパイラル型フィルタエレメントの横断面も結局は円形もしくは円形に酷似していること、貫通柱状支持体横断面に頂角が存在する場合巻き付けた際に濾過面間隔が頂角付近で狭まり濾過抵抗が大きいこと、より稠密に濾過空間を利用すること、更にフィルタエレメントをハウジングに装着するに当たって例えば汎用性の高いＯ−リングを介してなすに当たり円筒状のほうが好ましいことなどを考え併せると流体通路管としては円筒状を採用し得ることが好ましいことに変わり無い。
【０００４】
【発明が解決しようとする課題】
このような背景のもとに、合成樹脂製薄膜とその貫通柱状支持体の接合に当たり、例えばフィルタエレメントにおける合成樹脂製多孔質薄膜とその流体通路管である貫通柱状支持体の接合に当たり、貫通柱状支持体を多角柱に限定すること無く円柱状への適用はもとより、あまり形状にとらわれない広範な適用性を有する流体密な接合方法の開発を課題とした。更に、その方法を適用した接合体であるスパイラル型フィルタエレメントさらにはこれをハウジングに装着したスパイラル型フィルタアセンブリを開発することを課題とした。
【０００５】
ところで、合成樹脂製薄膜を貫通柱状支持体に接合する場面は、使い捨てのいわゆる輸液バッグ、輸血バッグなどを例示し得るが、以下には簡単のためスパイラル型フィルタエレメントを中心に詳述する。もとより発明の内容を限定するものではない。
【０００６】
特開平９−３１３８９８号によれば、従来の技術、すなわち円筒状の集液管に多孔質薄膜を取り付ける技術においては、図１に示すように袋を形成する多孔質薄膜の接合すべき二面１、２をそのまま延長して円筒状の集液管３を挟持し、この二面を、円筒を二つ割りにした構造を有する加熱した金型で、集液管３の周りおよびそれ自体同士に沿わせて押し付け溶着するとされている。しかし、両金型が近接する付近（図の４の箇所）では膜に対して円筒状の集液管３の軸中心へ向かう力の作用が乏しく加熱はされても押し付け圧力の不足は免れず、三角形の非接合の隙間５が出来ることが避けられとしている。更に、接合を確かにするために金型もしくは円筒状の集液管を９０°回転し改めて十分な圧力伝達の下に接合せざるを得ないが、薄い膜とは言え回転により管面上に重なり合うことにより膜と管と膜が構成する三角形の隙間５を埋めて接合する困難さが避け難いことも事実である。そしてこの困難さを回避するために集液管の断面形状に前記三角形に対応した且つ力を加え易いとし多角形とすることで解決策を見出していた。
【０００７】
【課題を解決するための手段】
しかしながら、本願発明者らは上記困難さを克服するに当たり、これらをより普遍的に捉え、貫通柱状支持体は押し付けられやすい形状を確保されることは不可欠でも、あまり形状上の制約が加えられること無く、貫通柱状支持体と多孔薄膜濾材間に十分な押し付け圧力が得られ、接合面に多孔質薄膜濾材が重なり合うことによる前記した三角形状の隙間が形成されないように多孔質薄膜濾材が配設されることを具体的に達成すれば良いことを見出し鋭意検討した。
【０００８】
その結果、下記の特徴を有する合成樹脂製薄膜濾材と柱状支持体とを接合した多孔薄膜製フィルタエレメントを提供するに至った。
【０００９】
すなわち、合成樹脂製多孔薄膜封着袋状濾材と柱状支持体とからなる多孔薄膜製フィルタエレメントにおいて、内外に流路材を配設した該合成樹脂製多孔薄膜封着袋状濾材を該合成樹脂製多孔薄膜封着袋状濾材内に連通する内部流路と一貫通端に該内部流路に連通するハウジング装着用スリーブを有する該貫通柱状支持体が貫通することにより構成される交差面より小さな貫通口が予め設けられた該合成樹脂製多孔薄膜封着袋状濾材を該柱状支持体が貫通して形成する該合成樹脂製多孔薄膜封着袋状濾材の包囲面と該柱状支持体とが密着接合されたフィルタエレメント、さらに該合成樹脂製多孔薄膜封着袋状濾材を該柱状支持体に巻き付けてなるスパイラル型多孔薄膜製フィルタエレメントを想到するに至った。
【００１０】
本願発明における合成樹脂製薄膜とは有孔、無孔いずれの膜でも良く更に不織布膜をも包含し、小さな貫通口が設けられ柱状支持体が貫通する際に裂けて広がり過ぎること無く貫通口が伸びながら押し広げられ貫通柱状支持体を包囲し、包囲面全体にわたって柱状支持体に密着すれば良く、好ましくはさらに締め付ける程度の作用を示す膜を意味する。
この合成樹脂製薄膜の形状は円形、楕円形、四角形をはじめとした多角形などの平面や球体、楕円体などの曲面、あるいはこれらの一部を組み合わせた例えば直方体、円筒体、球技用の各種ボ−ル状物体などの立体、具体的には医療現場における輸液バッグ、輸血用袋状物体、各種濾過現場における濾材などを含み、合成樹脂製薄膜が物体の一部を構成するものをも包含する。
【００１１】
有孔、無孔の合成樹脂製薄膜としては熱可塑性樹脂や熱可塑性エラストマ−の薄膜であり具体的にはポリエチレン、ポリプロピレン、ポリフッ化ビニリデン、ポリテトラフルオロエチレン、テトラフルオロエチレン−ヘキサフルオロプロピレン共重合体、テトラフルオロエチレン−パ−フルオロアルキルビニルエ−テル共重合体、テトラフルオロエチレン−エチレン共重合樹脂、ポリエ−テルスルホン、ポリスルホン、芳香族ポリカ−ボネ−ト、脂肪族ポリカ−ボネ−ト、ポリアミド、ポリオキシエチレンテレフタレ−ト、各種セルロ−スエステル等などのモノポリマ−、コポリマ−製の薄膜であり更にこれらを物理的もしくは化学的に修飾した薄膜をも含む。不織布製薄膜とはポリプロピレン、ポリオキシエチレンテレフタレ−ト、ポリアミドなどからなる表面から裏面まで空隙が連通している各種不織布の薄膜である。
【００１２】
なお、有孔の合成樹脂製薄膜においては孔の大きさには限界があり、前記した貫通口を押し広げる際に貫通口周辺の孔が同時に避けて押し広がること無く貫通口を大きくする場合は本願発明の対象外である。しかし、後述する補強材を貫通口周辺に接合し得る限りは貫通口の数分の１程度好ましくは数十分の１程度までの孔が許容し得る。
【００１３】
これら合成樹脂製薄膜を支える本願発明による柱状支持体とはこれら薄膜を貫通する柱状の支持体で略略棒状であって貫通部において両者が互いに接着剤や熱融着で接合されることによりその支持機能が果たされる。この柱状支持体は合成樹脂製薄膜が接合し得る限り材料上の限定はなく、薄膜と同一材質もしくは異種材質の合成樹脂などの他、ステンレススチ−ル、鋼、銅などの各種金属でも更にはセラミックでも構わない。
【００１４】
本願発明における柱状支持体の柱状とは通常の柱に見られる形状、すなわち円柱、四角柱あるいはこれらに類似の柱の形状を意味するが、多角柱にあってはその軸方向に直角の断面図のいずれの頂角も１８０度より小さい形状に限って対象とされる。これらの柱状支持体すべてに特徴的なことは、薄膜と支持体が貫通して形成される交差面が凹部を有しない形状を有することにある。換言するなら、「薄膜」の貫通口を柱状支持体が貫通した際に薄膜が裂けずに押し広げられ、あるいは裂けても微少で元の薄膜が新たに形成する上記の交差面に交わる包囲面が形成され、従来の薄膜面と支持体を沿わせ押し付けた際に発生する三角形状の隙間は全く構成されずに、柱状支持体を包囲しその全面にわたって密着し、好ましくは締め付け得るほどに密着するためには交差面周囲に凹部が存在することは厳に回避されねばならない事に基づく。結局、交差面と元の薄膜面が途切れること無く、すなわち隙間無く、連続しなければならない。さらに、交差面周囲には柱状支持体を締め付ける作用の無い直線部分も少なく、好ましくはこの直線部分が全く無く曲率を有する線で囲まれた交差面が形成されるのが良い。
【００１５】
ここに、貫通するとは文字どおり薄膜の少なくとも一個所の一面からその裏面に突き抜けていることを意味し、この貫通を容易ならしめるためには薄膜に予め前記交差面の外径よりも小さな貫通口を設けることが必要である。貫通口とは柱状支持体と薄膜が貫通後形成されるべき交差面内に引かれる少なくとも一本の線分および／あるいは同交差面内に画き得る小面である。前者においては一本（単一スリット）に限らず二本以上通常交差した線分（十字スリット、放射状スリット等）でも良いが、線分の両端はその延長上の交差面周辺との交点より内側に止められねばならない。後者においては、交差面に相似の小面が両者の重心を同じくして、この重心を通る対応する各線分が重なり合うように切り抜かれるのが好ましい。また、上記線分と小面の組み合わせでも良い。
【００１６】
重要なことには、貫通口は交差面内に収まり、貫通が果たせてその際押し広げられた薄膜が十分に柱状支持体を密着包囲する元の膜の伸張面、すなわち交差面に交わる包囲面が形成され柱状支持体を締め付け得れば種々選択し得る。あまりに小さい貫通口は貫通後の薄膜による強い柱状支持体締め付け力を期待し得る一方、貫通時に大きな力が作用して貫通口が広がりすぎて包囲面幅が一様に構成されないか、全く一部包囲面を形成しないことすら起こるので材質、温度、貫通柱状支持体の形状に応じて決定されねばならない。すなわち、上記十分に柱状支持体を密着包囲するとは包囲してできた包囲面が接合の際に接合代としての機能を発揮し得る形状あるいは幅を有することを意味する。包囲面の帯幅は適切な接合のために可能な限り同じ幅とし、後述する金型の伝熱面幅に近似した幅が好ましい。より具体的に述べるなら、円柱状の支持体に対しては貫通口の形状は交差平面と中心を同じくする小円が好ましく、貫通後形成される包囲面は同一幅を有する帯状となり接着や溶融融着による接合が容易となる。この際線分の貫通口を設けると交差面は平面でなく曲面となり包囲面も支持体回りに波を画く形状となり幅が周期的に変わり接合はやや難しくなる。
【００１７】
上記した柱状支持体と合成樹脂製薄膜の貫通状況を達成するためには薄膜の厚みが重要な因子となる。余りに膜厚が大なる際には予め設けられた貫通口は貫通に際し、裂けて広がるだけで包囲面が形成されがたいので、使用場面を想定して可能なら薄く加工することが欠かせない。膜厚が任意に選択し得る場合は包囲面が形成しやすくかつ柱状支持体を締め付ける力が強く作用するように決定されることが好ましい。従って、貫通口周辺は均一な厚みを有する薄膜であることが好ましく、避け得れば厚みの不均一な膜の接合部は貫通口としないように設計し加工する方が良い。
【００１８】
前記した薄膜の孔が大きい場合や薄膜がきわめて薄い場合あるいは更に、厚くとも避けやすい場合は亀裂が生じないよう貫通口周辺に薄膜と同一材質、あるいは異なっても使用上問題を生じない他の材質の有孔、無孔のフィルムすなわち補強材を貫通前に薄膜に接合しておくことが好ましい。また、膜厚が極めて薄く包囲面が形成されても支持体を締め付ける力が弱く、金型で加熱接合する際に密着しがたい場合も、上記同様に補強材を貫通前に薄膜に接合しておくことが好ましい。かかる補強材は薄膜の所定の位置に貫通を行わしめるための位置決め手段としても有効である。更に薄膜と支持体が直接接合しがたい場合の接合補助材として機能させることにも使用し得る。また、溶融点以下の温度で可能な限り小さな貫通口を貫通し、冷時支持体をより強く締め付ける方式は好ましい。かくして、材質はじめ種々の貫通要因を考慮して試行錯誤を繰り返し容易に貫通条件を決定し得る。
【００１９】
接合に当たっては前記交差面を取り巻く二分割された、幅が前記包囲幅に近似したヒ−タ−あるいは金型で取り囲み支持体と直接もしくは支持体と包囲薄膜幅の間に接合を容易にするフィルムを介在して溶着する。予め包囲幅が支持体を密着締め付けているので容易に接合し得るが、材料の組み合わせによってはヒ−タ−の押し付け圧力を十分に受け止めるべく半回転以下の回転を何度か与えヒ−タ−で押し付けると更に好ましい。
【００２０】
既に、合成樹脂製薄膜の形状の具体例として濾材に言及したが、これを貫通する柱状支持体としての流体流路管とからなる流体すなわち気体もしくは液体中に混入している固体を分離するスパイラル型多孔薄膜製フィルタエレメント製造に関する上述の合成樹脂薄膜と柱状支持体の接合方法適用ついて以下に詳述する。
【００２１】
このエレメントにおける濾材は合成樹脂製多孔薄膜封着袋状濾材であり、合成樹脂製多孔薄膜から作成された封筒や書類袋などに類似の形状をはじめとした種々の形状を有する袋状体の開口部位を封ずるため接着剤もしくは熱融着により、あるいは必要に応じ低融点のフィルムを介在させた熱融着により接合した合成樹脂の多孔質膜もしくは不織布膜の濾過用材料と理解して構わないし、製作順序も特に限定するものではない。更に言及するなら、形状としては長方形、正方形をはじめとした種々の矩形さらには三角形や台形など薄い平らな内部空間を有するもので良く、貫通すべき面が存在し接合されて後、貫通柱状支持体に巻き付け得る限り特に限定されるものではない。
【００２２】
このような濾材を作成する方法は既に知られているが、上記材質の中にはポリテトラフルオロエチレンの多孔薄膜で代表されるようにそれ自身だけでは封着袋状濾材に加工し得ない際には袋作成のための接合あるいは袋封着のための接合のために、例えばテトラフルオロエチレン−ヘキサフルオロプロピレン共重合体、テトラフルオロエチレン−パ−フルオロアルキルビニルエ−テル共重合体、テトラフルオロエチレン−エチレン共重合樹脂のフィルムを接合部に介在させるなどの常法が適用される。
【００２３】
一方、合成樹脂製多孔質薄膜封着袋状濾材を貫通し、支持する流体流路管は内部に流路を有しその流路は更に多孔もしくはスリットを介して流体流路管表面を経て合成樹脂製多孔質薄膜封着袋状濾材内に連通する。その流体流路管の合成樹脂製多孔質薄膜封着袋状濾材外に突き出た端部にはスリ−ブが設けられ流体密にハウジングと連通しハウジングに具備された濾過原料用の入口か透過流体用の出口かのいずれか一方の流路に連通される様構成されている。その際当然ながら、濾過原料と透過流体の混合が厳に回避されるようにその貫通部において前記接合方法により流体密に合成樹脂製多孔質薄膜封着袋状濾材と流体流路管が接合されねばならない。
【００２４】
この流体流路管の内部流路が他端まで延伸しておらずその他端付近において前記多孔もしくはスリットが表面に構成されていない限りにおいて、上記貫通部とは位置的に対向する合成樹脂製多孔質薄膜封着袋状濾材部位を貫通させて接合しても構わない。このように２個所貫通する方式においては、スリ−ブをハウジングに取り付けるに当たり合成樹脂製多孔質薄膜封着袋状濾材に触れること無く上記他端にだけ力を作用させて合成樹脂製多孔質薄膜封着袋状濾材を損傷すること無く押し込める特徴があり好ましい。このスリ−ブはＯ−リングを介してハウジングに着脱自在な取り付けを可能にすべく設計しても、ハウジングに接着や溶着あるいは嵌合により接続して使い捨て型に設計しても良い。なお、合成樹脂製多孔質薄膜封着袋状濾材の二つの貫通口に流体流路管を貫通すると最初の貫通により形成される包囲面は合成樹脂製多孔質薄膜封着袋状濾材内に形成されるがこの場合は最後の包囲面を保持したまま最初の貫通部において流体流路管を最初の貫通方向とは逆に引き戻して包囲面をめくり返して新たに包囲面を袋外に誘導するなどにより接合しやすい形態にすることが要せられる。
【００２５】
なお、濾過操作における濾過原料の流れ方向は合成樹脂製多孔質薄膜封着袋状濾材の内外いずれからでも良いが、合成樹脂製多孔質薄膜封着袋状濾材同士が接触するとか、合成樹脂製多孔質薄膜封着袋状濾材とハウジング内壁と接触することは濾過機能を著しく損なうので、必要に応じ合成樹脂製多孔質薄膜封着袋状濾材内外にネットもしくは不織布などの流路材（スペ−サとも呼称される）を配置して流体流路を確保しなければならない。またスペ−サは袋内にあっては単に配置しても、一部点付け、線付けにより袋に部分的に接合しても、合成樹脂製多孔質薄膜封着袋状濾材作成時にその周辺部で一緒に接合しても構わない。また、袋外のスペ−サと共に行っても良い。要するに流量が確保し得て濾過面が効率的に使用される限り種々な固定手段を適用して構わないが、最終的に支持体を中心軸に時計回りあるいはその反対回りに巻きつけるに当たって支障が無ければ問題ない。
【００２６】
また、ハウジングに収容してハウジングの外部が熔接により、特に金属熔接による場合はその周辺温度が高くなるので合成樹脂製多孔質薄膜封着袋状濾材自身が熱的に変化することが予想される際には熔接周囲から合成樹脂製多孔質薄膜封着袋状濾材を離すためくびれた形状にすることなどの工夫が必要なことは言を待たない。
【００２７】
【発明の実施の形態】
本願発明になる合成樹脂製薄膜と柱状支持体との接合方法の一例を図２により説明する。図２は点滴用の輸液バッグに見られるような円筒ノズルを備えた密閉容器製作における合成樹脂製薄膜と円筒ノズル接合方法の要部、すなわち膜1枚と円筒ノズル１個との接合方法を示すもので矢印は手順の流れ（▲１▼→▲２▼→▲３▼→▲４▼→▲５▼）を示す。段階▲１▼において１１は合成樹脂製薄膜であり、次いで▲２▼のように打ち抜きによりより貫通口が形成される。図の▲２▼において点線１２はノズル貫通後に形成されるノズル１４の周面と平面状薄膜１１とが交差する周面を示し、実線１３は周面１２と中心を同じくした該合成樹脂製薄膜の周面１２の径よりも小さい円形貫通口を示す。▲３▼において貫通口１３には薄膜１１の下方から円筒ノズル１４が無理に貫通され、貫通の際の摩擦により合成樹脂製薄膜１１が伸びてノズル１４を取り囲む包囲面１５を形成する。▲４▼においてこの包囲面１５を金型ヒ−タ−１６により挟み加圧下に加熱溶着する。なお、▲５▼においては更に、回転により金型と円筒の位置関係を９０°変更した状況を示した。このようにして包囲面自身支持体を締め付けながら、更にその状態に力を加え、密着、溶着し得た。
【００２８】
【実施例】
以下本願発明を実施例により説明する。
実施例１．スパイラル型フィルタエレメント
図３の▲１▼から▲６▼は内外にテトラフルオロエチレン−パ−フルオロアルキルビニルエ−テル共重合体（以下ＰＦＡと略記）製のネット２１、２３（目開き６０メッシュ、線径１１０μｍ、見掛け厚さ２００μｍ）と、ポリテトラフルオロエチレン（以下ＰＴＦＥと略記）製多孔質濾過膜２２（公称孔径０．２μｍ、厚み２０μｍ、開口率７０％）とを使用して、左右対称の六角形封着袋状濾材とする作成手順を矢印と共に示したものである。図において、段階▲１▼に示したようにＰＴＦＥ濾過膜２２を２つ折りにして五角形とし、その辺ａ１とａ２の間にはテトラフルオロエチレン−ヘキサフルオロプロピレン共重合体（以下ＦＥＰと略記）からなる細い薄いフィルム２０（幅３ｍｍ、厚み１０μｍ。図４参照）を介在させて重ねて溶融接合して▲２▼に示すエンドレス状態とし（接合部位は太線で示した。）、▲３▼で示すようにこの接合された濾過膜２２の層間にやや小さい寸法の六角形のネット２１を差し挟む。更に、▲４▼で示したように外部に位置するネット２３は２つ折りにして濾過膜２２よりもやや大きい寸法の六角形とし、その辺ｂ１とｂ２をそのまま重ねて熱融着し、このエンドレス状に接合されたネット２３の層間に、▲３▼においてネット２１を差し挟んだ濾過膜２２を▲５▼のように差し挟む。この状態の積層状態を図４に示した。次いで四辺ｃ，ｄ，ｅ、ｆにおいてＰＴＦＥ濾過膜２２と内外のＰＦＡネット２１、２３を重畳したままで一挙に熱融着し▲６▼に示す状態とした。
【００２９】
形成された六角形封着袋状濾材２４（太線部は上記の接合部を強調して示したものである。）の対称軸部に▲８▼に示した多孔ＰＦＡ製流体流路管２５（貫通部の直径１５ｍｍ、内径１０ｍｍ、スリ−ブ外径２０ｍｍ、スリ−ブ内径１６ｍｍ、表面には多数の孔が穿ってあり内部の円筒流路に連通している。）を貫通するために図中▲７▼（▲６▼の裏面であり溶着部を示した。）のように直径１２ｍｍの貫通用小面を切り取って切り欠きｈ及びｇを形成した。次いで、▲８▼に示した流体流路管２５をそれより太径のスリ−ブ部分２５ｂとは反対の閉塞端部２５ａをｇから濾過膜２２により形成された袋状の濾過膜の内部を通して差し込んでｈに向けて貫通し、ｇの部位では流体流路管を貫通とは逆方向にわずかに引き戻して一旦袋内部に構成された濾過膜２２の包囲面をめくり返しｇとｈの部位に流体流路管２５の周りに密着する二つの包囲面を構成した。
【００３０】
以下、図２において説明したように金型（本実施例においては、要部は４２０〜４４０℃に制御された幅４ｍｍの二分真鍮環から構成されている。）により加圧、加熱し、更に金型中で流体流路管を９０°回転し、加圧、加熱、融着した。次いで、▲９▼の平行な線分２６ａ、２６ｂ、２６ｃ、２６ｄ……で示したように濾材の部分融着を行い、最後に濾材２４を図５、６のように流体流路管２５回りに巻きつけてスパイラル型フィルタエレメント２７に仕上げた。
【００３１】
また、入口（又は出口）３２を有したＳＵＳ３１６Ｌ製の円筒ハウジング胴体２８（内径３５ｍｍ、スパイラル型フィルタエレメント収容部長さ８２ｍｍ）に流体流路管２５のスリ−ブ２５ｂを嵌合密封し、出口（又は入口）３３を有するハウジングキャップ２９を溶接部３４で熔接し密封し、スパイラル型フィルタアセンブリ３５（胴部外径４０ｍｍ、両端出入り口雄ネジを含めた全長１２７ｍｍ）を完成した。熔接部３４はｈ近傍のため濾材はハウジング内壁より離れており熔接の影響を受けること無く損傷無しに組み立てられた。
【００３２】
比較の実験により、上記線分状の部分融着の無い濾材はハウジング内壁と接触し、特に袋内に濾過原料を供給する際に接触が著しく濾過面積が有効に機能しなかった。従って、上述ないしは類似の濾材加工は欠かせず、線分に限らず、点付け、あるいは線付けとの組み合わせが欠かせない。あるいは全く手法を違えて巻かれた濾材の周囲を所々リングで囲い込む、紐で縛るとか、流動抵抗の少ない不織布で包囲するなどしてハウジング内壁と濾材表面の間に何らかの間隙を設定することが要せられた。
【００３３】
【発明の効果】
合成樹脂製薄膜に予め貫通口を設けておきこれより大きな断面を有する柱状支持体を貫通すると合成樹脂製薄膜が伸びて貫通部周辺の支持体を密着する包囲面が形成され、それゆえに簡単な接合が特に融着による方法が適用し得るところとなった。その際、薄膜も有孔、無孔を問わず、薄膜の厚みも補強材が適用し得る限り実質的に下限が無く、上限は伸び縮みする限り厚い合成樹脂製薄膜にも適用し得る。従来の薄膜二枚を支持体に沿わせ、やむを得ずに生ずる三角形近似の隙間形状に逆に支持体形状を合致させ接合する先行技術とは異なり、断面形状に凹面が無い限り幅広く支持体形状を選択し得、適用幅が広い特徴をもたらした。同時に本方法を適用して流動抵抗の少ないスパイラル型フィルタエレメントを提供し得るに至った。
【図面の簡単な説明】
【図１】膜と管と膜が構成する角型の隙間を示した図である。
【図２】合成樹脂製薄膜と柱状支持体との接合方法を示した図である。
【図３】六角形封着袋状濾材作成手順と流体流路管接合手順を示した図である。
【図４】図３の段階▲７▼における六角形封着袋状濾材の積層状態を示す断面図である。
【図５】本発明のスパイラル型フィルタエレメントの斜視図である。
【図６】本発明のスパイラル型フィルタエレメントの正面図である。
【図７】本発明のスパイラル型フィルタエレメントを組み込んだスパイラル型フィルタアセンブリの断面正面図である。
【符号の説明】
１１ 合成樹脂製薄膜
１２ ノズルと薄膜が交差する周面
１３ 貫通口
１４ ノズル
１５ 包囲面
２１ ネット
２２ 濾過膜
２３ ネット
２４ 封着袋状濾材
２５ 多孔ＰＦＡ製流体流路管
２５ａ 閉塞端部
２５ｂ スリーブ部分
２８ ハウジング胴体
２９ ハウジングキャップ
３２ 入口（又は出口）
３３ 出口（又は入口）
３４ 溶接部
３５ スパイラル型フィルタアセンブリ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spiral type filter element formed by joining a synthetic resin porous film for separating solids in the flow body through the columnar support.
[0002]
[Prior art]
For example, various types of spiral filter elements have been proposed, and an opening of a porous thin film bag-like filter medium has an internal channel that is one of the supports in the present application and communicates with it in the axial direction. Methods have been proposed for joining fluid passage tubes having extending openings. Furthermore, in Japanese Patent Laid-Open No. 9-313898, an improved method is proposed in which an envelope-shaped filter medium is stretched as it is and placed in a state along one edge of a fluid passage pipe also called a collecting pipe having a polygonal cross section. ing.
[0003]
However, even if such an improvement method is proposed, it is desirable to adopt a cylindrical support for cutting, material arrangements and other production reasons, not for a support having a polygonal cross section in the above joining scene. The cross section of the spiral filter element is eventually circular or very similar to a circular shape, and when there is an apex angle in the cross section of the penetrating columnar support, the interval between the filtration surfaces becomes narrow near the apex angle Considering the fact that the filtration resistance is large, that the filtration space is used more densely, and that the cylindrical element is preferable for mounting through the O-ring, for example, when mounting the filter element to the housing. As the passage tube, it is preferable that a cylindrical shape can be adopted.
[0004]
[Problems to be solved by the invention]
Under such a background, when joining a synthetic resin thin film and its through columnar support, for example, when joining a synthetic resin porous thin film in a filter element and a through columnar support that is a fluid passage pipe, a through columnar shape is used. The object of the present invention was to develop a fluid-tight joining method having a wide range of applicability that is not limited to the shape of the column, as well as the cylindrical shape without limiting the support to a polygonal column. Furthermore, another object of the present invention is to develop a spiral filter element which is a joined body to which the method is applied, and a spiral filter assembly in which the filter element is mounted on a housing.
[0005]
By the way, although the scene which joins a synthetic resin thin film to a penetration pillar-shaped support body can illustrate a disposable so-called infusion bag, a blood transfusion bag, etc., it explains in full detail focusing on a spiral type filter element below for simplicity. It does not limit the content of the invention.
[0006]
According to Japanese Patent Laid-Open No. 9-313898, in the conventional technique, that is, the technique of attaching a porous thin film to a cylindrical liquid collecting tube, two surfaces to be joined to form a bag as shown in FIG. 1 and 2 are extended as they are to sandwich a cylindrical liquid collecting tube 3, and these two surfaces are heated molds having a structure in which the cylinder is divided into two parts, and around the liquid collecting tube 3 and along each other. It is supposed to be pressed and welded. However, in the vicinity of the two molds (4 in the figure), the action of the force toward the axial center of the cylindrical liquid collecting tube 3 is poor with respect to the membrane, and even if it is heated, a lack of pressing pressure is inevitable. It is said that the triangular non-joint gap 5 can be avoided. Furthermore, in order to ensure the bonding, the mold or the cylindrical liquid collecting tube must be rotated 90 ° and bonded again under sufficient pressure transmission. It is also true that it is difficult to avoid the difficulty of joining by filling the triangular gap 5 formed by the membrane, the tube and the membrane by overlapping. In order to avoid this difficulty, a solution has been found by making the cross-sectional shape of the liquid collecting tube a polygonal shape corresponding to the triangle and making it easy to apply a force.
[0007]
[Means for Solving the Problems]
However, in order to overcome the above difficulties, the inventors of the present application consider these more universally, and it is indispensable that the penetrating columnar support has a shape that is easy to be pressed, but there are too many restrictions on the shape. The porous thin film filter medium is disposed so that a sufficient pressing pressure is obtained between the through columnar support and the porous thin film filter medium, and the above-described triangular gap is not formed due to the overlap of the porous thin film filter medium on the joint surface. We have sought to find out if we can achieve this specifically.
[0008]
As a result, it has provided a porous thin steel filter element formed by joining a synthetic resin film medium and the columnar support having the following characteristics.
[0009]
That is , in a porous thin film filter element composed of a synthetic resin porous thin film sealing bag-shaped filter medium and a columnar support, the synthetic resin porous thin film sealing bag-shaped filter medium in which a flow passage material is disposed inside and outside the synthetic resin. intersecting surfaces constructed by the through columnar support through having a housing mounting pickpocket over blanking communicating with said inner flow channel inside flow path and the first through end which communicates with the manufacturing porous thin sealing bag shaped inner filter medium Surrounding surface of the synthetic resin porous thin film sealing bag-like filter medium, wherein the columnar support penetrates the synthetic resin porous thin film sealing bag-like filter medium provided with a smaller through-hole in advance, and the columnar support. And a spiral porous thin film filter element obtained by winding the synthetic resin porous thin film sealing bag-like filter medium around the columnar support.
[0010]
The synthetic resin thin film in the present invention may be a perforated or non-porous film, and further includes a non-woven membrane, and a through-hole is formed without being excessively split and split when a small through-hole is provided and the columnar support penetrates. The film may be expanded while being stretched so as to surround the penetrating columnar support and be in close contact with the columnar support over the entire surrounding surface.
The shape of this synthetic resin thin film is round, elliptical, polygonal and other polygonal planes, curved surfaces such as spheres, ellipsoids, or combinations of these, such as rectangular parallelepipeds, cylinders, and ball games Including solid objects such as ball-shaped objects, specifically infusion bags at medical sites, transfusion bag-like objects, filtering materials at various filtration sites, etc., including those in which a synthetic resin thin film forms part of the object To do.
[0011]
Perforated and non-porous synthetic resin thin films are thermoplastic resin and thermoplastic elastomer thin films, specifically polyethylene, polypropylene, polyvinylidene fluoride, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer Polymer, Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, Tetrafluoroethylene-ethylene copolymer resin, Polyethersulfone, Polysulfone, Aromatic polycarbonate, Aliphatic polycarbonate, Polyamide And thin films made of monopolymers and copolymers such as polyoxyethylene terephthalate, various cellulose esters, etc., and these are physically or chemically modified. The nonwoven fabric thin film is a thin film of various nonwoven fabrics in which voids communicate from the front surface to the back surface made of polypropylene, polyoxyethylene terephthalate, polyamide or the like.
[0012]
In addition, in the porous synthetic resin thin film, there is a limit to the size of the hole, and when expanding the through hole, avoid the holes around the through hole at the same time and enlarge the through hole without expanding. It is out of the scope of the present invention. However, as long as a reinforcing material to be described later can be joined to the periphery of the through-hole, holes of about a fraction of the through-hole, preferably up to about a few tens, can be allowed.
[0013]
The columnar support according to the present invention that supports these synthetic resin thin films is a columnar support that penetrates these thin films and is substantially rod-shaped, and is supported by bonding them together with an adhesive or heat fusion at the penetration part. The function is fulfilled. The columnar support is not limited in material as long as a synthetic resin thin film can be joined. In addition to a synthetic resin of the same material or a different material from the thin film, various kinds of metals such as stainless steel, steel, and copper can be used. Ceramic may be used.
[0014]
The columnar shape of the columnar support in the present invention means a shape found in a normal column, that is, a columnar shape, a quadrangular column shape, or a similar column shape, but in the case of a polygonal column, a sectional view perpendicular to the axial direction. Any of the apex angles is limited to a shape smaller than 180 degrees. What is characteristic of all these columnar supports is that the intersecting surface formed through the thin film and the support has a shape having no recess. In other words, when the columnar support passes through the through hole of the “thin film”, the thin film is expanded without tearing, or even if it is torn, the surrounding surface intersects with the above-mentioned intersecting surface that is newly formed by the original thin film The triangular gap generated when the conventional thin film surface and the support are pressed together is not formed at all, and the columnar support is surrounded and closely adhered over the entire surface, preferably close enough to be tightened. In order to do this, the presence of recesses around the crossing plane must be strictly avoided. Eventually, the intersecting surface and the original thin film surface must be continuous without interruption, that is, without a gap. Further, there are few straight portions that do not have the effect of tightening the columnar support around the intersecting surface, and it is preferable that an intersecting surface surrounded by a line having a curvature without any straight portions is formed.
[0015]
Here, literally means that the thin film penetrates from one surface of the thin film to the back surface, and in order to facilitate this penetration, the thin film is previously provided with a through hole smaller than the outer diameter of the intersecting surface. It is necessary to provide it. The through-hole is at least one line segment drawn in the intersecting surface to be formed after the columnar support and the thin film are penetrated and / or a facet that can be drawn in the intersecting surface. The former is not limited to one (single slit), but may be a line segment (cross slit, radial slit, etc.) that normally intersects two or more, but both ends of the line segment are inside the intersection with the periphery of the intersection on the extension. Must be stopped by. In the latter, it is preferable that the facets similar to the intersecting plane have the same centroid, and the corresponding line segments passing through the centroid are cut out so as to overlap. Moreover, the combination of the said line segment and a facet may be sufficient.
[0016]
Importantly, the through-hole fits within the crossing plane, and the thin film that can be penetrated and then spread out sufficiently fully surrounds the columnar support, ie, the enveloping surface that intersects the crossing plane. Can be selected in various ways. A too small through-hole can be expected to have a strong columnar support tightening force due to the thin film after penetrating, but a large force acts at the time of penetration and the through-hole expands too much, so that the surrounding surface width is not configured uniformly or not at all Since it does not even form the surrounding surface, it must be determined according to the material, temperature, and shape of the penetrating columnar support. That is, to sufficiently surround the columnar support means that the surrounding surface formed has a shape or width capable of exhibiting a function as a joining margin at the time of joining. The band width of the surrounding surface is preferably the same as much as possible for appropriate joining, and is preferably a width that approximates the heat transfer surface width of the mold described later. More specifically, for a cylindrical support, the shape of the through-hole is preferably a small circle having the same center as the intersecting plane, and the enveloping surface formed after penetrating becomes a band having the same width and is bonded or melted. Joining by fusion becomes easy. At this time, if a through hole is provided for the line segment, the intersecting surface becomes a curved surface instead of a flat surface, and the surrounding surface also has a shape that draws a wave around the support, so that the width changes periodically and joining becomes somewhat difficult.
[0017]
The thickness of the thin film is an important factor for achieving the penetration state between the columnar support and the synthetic resin thin film. When the film thickness is excessively large, it is indispensable to form the through-hole provided in advance as thin as possible in consideration of the usage situation, because it is difficult to form an enveloping surface simply by tearing and spreading. In the case where the film thickness can be arbitrarily selected, it is preferable that the surrounding surface is easily formed and the force for tightening the columnar support is strongly determined. Therefore, it is preferable that the periphery of the through-hole is a thin film having a uniform thickness. If it can be avoided, it is better to design and process the joint portion of the film having a non-uniform thickness not to be a through-hole.
[0018]
If the thin film has a large hole, if the thin film is very thin, or even if it is thick, it is easy to avoid it. It is preferable to bond a perforated film or a non-porous film, ie, a reinforcing material, to the thin film before penetrating. In addition, even if the film thickness is extremely thin and the surrounding surface is formed, the force to tighten the support is weak, and even if it is difficult to make a close contact when heat-bonding with a mold, the reinforcing material is bonded to the thin film before penetration as above. It is preferable to keep it. Such a reinforcing material is also effective as a positioning means for penetrating a predetermined position of the thin film. Furthermore, it can also be used to function as a bonding aid when it is difficult to bond the thin film and the support directly. Further, a method of penetrating as small a through-hole as possible at a temperature equal to or lower than the melting point and tightening the support more strongly when cold is preferable. Thus, the penetration condition can be easily determined by repeating trial and error in consideration of various penetration factors including the material.
[0019]
In joining, the film is divided into two parts surrounding the intersecting surface, and is surrounded by a heater or a mold whose width is close to the surrounding width, and facilitates the joining between the support and the support and the surrounding thin film width. It welds through. Since the surrounding width is tightly fastened to the support in advance, it can be easily joined. However, depending on the combination of materials, the heater is given several rotations of half or less to sufficiently receive the pressing pressure of the heater. It is more preferable to press with.
[0020]
Already mentioned the filter medium as a specific example of the shape of the synthetic resin thin film, the spiral consisting of a fluid channel tube as a columnar support penetrating therethrough, that is, a spiral that separates solids mixed in gas or liquid The method for joining the above-mentioned synthetic resin thin film and columnar support relating to the production of a filter element made of a porous porous thin film will be described in detail below.
[0021]
The filter medium in this element is a synthetic resin porous thin film sealing bag-shaped filter medium, and openings of bag-shaped bodies having various shapes such as envelopes and document bags made from a synthetic resin porous thin film. It may be understood as a filtering material for porous or non-woven membranes of synthetic resin bonded by adhesive or heat fusion to seal the site, or by heat fusion with a low melting point film as necessary. The production order is not particularly limited. In addition, the shape may be a rectangle, various rectangles including squares, or a thin flat internal space such as a triangle or a trapezoid. There is no particular limitation as long as it can be wound around the body.
[0022]
Although a method for producing such a filter medium is already known, some of the above materials cannot be processed into a sealed bag-like filter medium by itself, as represented by a porous thin film of polytetrafluoroethylene. For bonding for bag making or bag sealing, for example, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, tetrafluoroethylene Conventional methods such as interposing an ethylene-ethylene copolymer resin film in the joint are applied.
[0023]
On the other hand, the fluid flow path pipe that penetrates and supports the porous thin film sealing bag filter material made of synthetic resin has a flow path inside, and the flow path is further synthesized through the surface of the fluid flow path pipe through a porous or slit. It communicates with the resin porous thin film sealing bag-like filter medium. A sleeve is provided at the end of the fluid channel tube protruding out of the synthetic resin porous thin film sealing bag-like filter medium, fluidly communicating with the housing, and passing through the inlet for the filtration material provided in the housing. It is configured to communicate with either one of the fluid outlets. In this case, as a matter of course, the synthetic resin porous thin film sealing bag-like filter medium and the fluid flow path pipe are joined fluid-tightly by the joining method in the through-hole so that mixing of the filtration raw material and the permeated fluid is strictly avoided. I have to.
[0024]
As long as the internal flow path of the fluid flow pipe does not extend to the other end and the porous or slit is not formed on the surface in the vicinity of the other end, the synthetic resin porous that is positioned to face the penetrating portion is provided. The thin film sealing bag-shaped filter medium part may be penetrated and joined. Thus, in the method of penetrating two places, when attaching the sleeve to the housing, a force is applied only to the other end without touching the synthetic resin porous thin film sealing bag-like filter medium, and the synthetic resin porous thin film The sealing bag-shaped filter medium is preferable because it can be pushed in without being damaged. The sleeve may be designed to be detachably attached to the housing via an O-ring, or may be designed to be disposable by connecting to the housing by adhesion, welding or fitting. When the fluid channel tube is passed through the two through-holes of the synthetic resin porous thin film sealing bag-shaped filter medium, the surrounding surface formed by the first penetration is formed in the synthetic resin porous thin film sealing bag-shaped filter medium. In this case, however, the fluid passage pipe is pulled back in the first penetrating portion opposite to the first penetrating direction while holding the last surrounding surface, and the surrounding surface is turned over to newly guide the surrounding surface outside the bag. For example, it is necessary to make it easy to join.
[0025]
In addition, the flow direction of the filtration raw material in the filtration operation may be from either inside or outside of the synthetic resin porous thin film sealing bag-like filter medium, but the synthetic resin porous thin film sealing bag-like filter medium is in contact with each other or made of synthetic resin. Contacting the porous thin film sealing bag-shaped filter medium with the inner wall of the housing significantly impairs the filtration function. Therefore, if necessary, a flow path material (space, such as a net or non-woven fabric) is inserted inside or outside the porous thin film sealing bag-shaped filter medium made of synthetic resin. The fluid flow path must be ensured by arranging the same). In addition, the spacer may be simply placed in the bag, or may be partly attached or partially joined to the bag by wire attachment, and the periphery of the spacer may be used when making a synthetic resin porous thin film sealed bag-like filter medium. You may join together in a part. Moreover, you may carry out with the spacer outside a bag. In short, various fixing means may be applied as long as the flow rate can be secured and the filtration surface can be used efficiently, but there is a problem in finally winding the support clockwise around the central axis or vice versa. If there is no, there is no problem.
[0026]
In addition, when the outside of the housing is housed in the housing and is welded, especially in the case of metal welding, the surrounding temperature becomes high, so the synthetic resin porous thin film sealing bag-like filter medium itself is expected to change thermally. At that time, there is no need to say that it is necessary to devise a constricted shape to separate the synthetic resin porous thin film sealing bag-like filter medium from the periphery of the weld.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
An example of a method of joining the synthetic resin thin film and the columnar support according to the present invention will be described with reference to FIG. FIG. 2 shows the main part of the synthetic resin thin film and cylindrical nozzle joining method in the manufacture of a sealed container having a cylindrical nozzle as seen in an infusion bag for infusion, that is, the joining method of one membrane and one cylindrical nozzle. The arrows in the figure indicate the flow of the procedure (▲ 1 ▼ → ▲ 2 ▼ → ▲ 3 ▼ → ▲ 4 ▼ → ▲ 5 ▼). In step (1), reference numeral 11 denotes a synthetic resin thin film, and then a through-hole is formed by punching as in (2). In (2) in the figure, the dotted line 12 indicates the peripheral surface where the peripheral surface of the nozzle 14 formed after penetrating the nozzle and the planar thin film 11 intersect, and the solid line 13 indicates the synthetic resin thin film having the same center as the peripheral surface 12. The circular through-hole smaller than the diameter of the surrounding surface 12 is shown. In {circle around (3)}, the cylindrical nozzle 14 is forcibly penetrated into the through-hole 13 from below the thin film 11, and the synthetic resin thin film 11 is stretched by friction during penetration to form the surrounding surface 15 surrounding the nozzle 14. In (4), the surrounding surface 15 is sandwiched between mold heaters 16 and heated and welded under pressure. In (5), a situation is shown in which the positional relationship between the mold and the cylinder is changed by 90 ° by rotation. In this way, while the surrounding surface itself was tightened, a force was further applied to the state to adhere and weld.
[0028]
【Example】
The present invention will be described below with reference to examples.
Example 1. Spiral filter element (1) to (6) in FIG. 3 are nets 21 and 23 (opening mesh 60 mesh) made of tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (hereinafter abbreviated as PFA) inside and outside. Using a 110 μm wire diameter and an apparent thickness of 200 μm) and a porous filtration membrane 22 made of polytetrafluoroethylene (hereinafter abbreviated as PTFE) (nominal pore diameter of 0.2 μm, thickness of 20 μm, opening ratio of 70%) The procedure for preparing a hexagonal sealing bag-shaped filter medium is shown with arrows. In the figure, the PTFE filtration membrane 22 is folded in half to form a pentagon as shown in step (1), and a tetrafluoroethylene-hexafluoropropylene copolymer (hereinafter abbreviated as FEP) is formed between the sides a1 and a2. A thin thin film 20 (width: 3 mm, thickness: 10 μm; see FIG. 4) is overlapped and melt-bonded to obtain an endless state indicated by (2) (the bonding site is indicated by a thick line), and indicated by (3). In this way, a hexagonal net 21 having a slightly smaller dimension is sandwiched between the layers of the joined filtration membranes 22. Further, as shown in (4), the net 23 located outside is folded in half to form a hexagon having a size slightly larger than the filtration membrane 22, and the sides b1 and b2 are overlapped as they are and heat-sealed. Between the layers of the nets 23 joined in a shape, the filtration membrane 22 with the net 21 sandwiched in (3) is sandwiched as in (5). The laminated state in this state is shown in FIG. Next, the PTFE filtration membrane 22 and the inner and outer PFA nets 21 and 23 were superposed on the four sides c, d, e, and f, and then heat-sealed at a stroke to obtain the state shown in (6).
[0029]
The perforated PFA fluid flow channel tube 25 (8) shown in (8) at the symmetrical axis portion of the formed hexagonal sealing bag-shaped filter medium 24 (the bold line portion is shown by emphasizing the joint portion). In order to penetrate through, the diameter of the penetrating portion is 15 mm, the inner diameter is 10 mm, the sleeve outer diameter is 20 mm, the sleeve inner diameter is 16 mm, and the surface has a large number of holes communicating with the internal cylindrical flow path. A small surface for penetration having a diameter of 12 mm was cut out to form notches h and g as shown in (7) (the back side of (6), showing the welded portion). Next, the fluid passage pipe 25 shown in (8) is passed through the inside of a bag-like filtration membrane formed by the filtration membrane 22 from the closed end portion 25a opposite to the larger diameter sleeve portion 25b. It is inserted and penetrates toward h, and at the part of g, the fluid flow path pipe is slightly pulled back in the opposite direction to the penetration and the surrounding surface of the filtration membrane 22 once formed inside the bag is turned over to the parts of g and h. Two surrounding surfaces closely contacting around the fluid flow path tube 25 were formed.
[0030]
Hereinafter, as described with reference to FIG. 2, pressurization and heating are performed by a mold (in this embodiment, a main part is composed of a 4 mm-width half-brass ring controlled at 420 to 440 ° C.), and further The fluid channel tube was rotated 90 ° in the mold, and was pressurized, heated and fused. Next, the filter medium is partially fused as indicated by the parallel line segments 26a, 26b, 26c, 26d..., And finally the filter medium 24 is placed around the fluid flow path pipe 25 as shown in FIGS. The spiral filter element 27 was finished.
[0031]
Further, the sleeve 25b of the fluid flow pipe 25 is fitted and sealed to a cylindrical housing body 28 made of SUS316L having an inlet (or outlet) 32 (inner diameter 35 mm, spiral filter element accommodating portion length 82 mm). Alternatively, the housing cap 29 having the inlet 33 is welded and sealed at the welded portion 34 to complete the spiral filter assembly 35 (the outer diameter of the body portion is 40 mm, and the total length is 127 mm including the male threads at both ends). Since the welded portion 34 is in the vicinity of h, the filter medium is separated from the inner wall of the housing and is assembled without being damaged without being affected by welding.
[0032]
According to a comparative experiment, the above-mentioned line-shaped filter material without partial fusion contacted with the inner wall of the housing, and particularly when the filtration raw material was supplied into the bag, the contact area was remarkably not functioning effectively. Therefore, the above-mentioned or similar processing of filter media is indispensable, and not only a line segment but also a combination with dot marking or line marking is indispensable. Alternatively, it is possible to set a certain gap between the inner wall of the housing and the surface of the filter medium by surrounding the filter medium wrapped by a completely different method with rings, tying it with a string, or surrounding it with a non-woven fabric with low flow resistance. It was necessary.
[0033]
【The invention's effect】
If a through hole is provided in advance in the synthetic resin thin film and a columnar support having a larger cross section is penetrated, the synthetic resin thin film is stretched to form an enclosing surface that closely contacts the support around the through portion. In particular, the fusion method can be applied. At that time, regardless of whether the thin film is perforated or non-porous, the thickness of the thin film has substantially no lower limit as long as the reinforcing material can be applied, and the upper limit can be applied to a thick synthetic resin thin film as long as it expands and contracts. Unlike the prior art, where two conventional thin films are placed along the support, and the support shape is matched to the triangular shape of the gap, which is unavoidable, and joined, the support shape can be selected from a wide range as long as there is no concave surface. Yes, resulting in a wide range of features. At the same time, the present method can be applied to provide a spiral filter element with low flow resistance.
[Brief description of the drawings]
FIG. 1 is a diagram showing a square gap formed by a membrane, a tube, and a membrane.
FIG. 2 is a view showing a method of joining a synthetic resin thin film and a columnar support.
FIG. 3 is a diagram showing a hexagonal sealing bag-shaped filter medium preparation procedure and a fluid flow path pipe joining procedure.
4 is a cross-sectional view showing a stacked state of hexagonal sealing bag-like filter media in step (7) of FIG. 3. FIG.
FIG. 5 is a perspective view of a spiral filter element of the present invention.
FIG. 6 is a front view of a spiral filter element of the present invention.
FIG. 7 is a cross-sectional front view of a spiral filter assembly incorporating the spiral filter element of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Synthetic resin thin film 12 Circumferential surface 13 where a nozzle and a thin film cross | intersect 13 Through-hole 14 Nozzle 15 Enclosure surface 21 Net 22 Filtration membrane 23 Net 24 Sealing bag-like filter medium 25 Porous PFA fluid flow path pipe 25a Closed end 25b Sleeve portion 28 Housing body 29 Housing cap 32 Inlet (or outlet)
33 Exit (or entrance)
34 Welding part 35 Spiral type filter assembly
