( onaninso polymer® PTFE ndi polymer® FEP & PFA Specifications ) PTFE's mechanical properties ndi yotsika poyerekeza ndi mapulasitiki ena, koma katundu wake amakhalabe pa mlingo wothandiza pa kutentha kwakukulu kwa -100 ° F mpaka + 400 ° F (- 73°C mpaka 204°C).
Makhalidwe Odziwika a Polymer® PTFE Fluoropolymer Resins
Kutentha kukana
Kutentha pamwamba pa 77 ° C sibwino kwa zigawo zambiri za elastomers ndi mapulasitiki, pamene PTFE imapirira kutentha kwambiri mpaka 260 ° C.Ngakhale pansi pa 77 ° C, ngati ma asidi owononga zitsulo ndi zosungunulira za organic aphatikizidwa, liners ndi zigawo zikuluzikulu za PTFE nthawi zambiri amakonda chifukwa elastomers ndi mapulasitiki ena nthawi zambiri alibe kukana zosungunulira kutupa ndi kufewetsa.
Chemical Inertness
Ndi Chemical inertness, tikutanthauza kuti PTFE fluorocarbon utomoni akhoza mosalekeza kukhudzana ndi chinthu china popanda detectable mankhwala zimachitika.Nthawi zambiri, PTFE fluorocarbon resins ndi mankhwala inert.Komabe, mawu awa, monga ma generalizations onse, ayenera kukhala oyenerera ngati akuyenera kukhala olondola.Chiyeneretso sichidzabweretsa chisokonezo, komabe, ngati munthu amakumbukira mfundo zazikulu za khalidwe la PTFE resins.
Mafotokozedwe anthawi zonse a mayeso osiyanasiyana amatha kusokeretsa, chifukwa amatha kuphatikizira mitundu yosiyanasiyana ya machitidwe a "Chemical".Ngati kufotokozerako kukhale komveka bwino, kuyenera kusiyanitsa pakati pa zochitika za mankhwala ndi zochitika zakuthupi monga kuyamwa.Kufotokozera kuyenera kupangitsa kuti wogwiritsa ntchitoyo aganizire za kugwirizana kwa thupi ndi mankhwala zomwe zingakhudze ntchito inayake.
Mwachitsanzo, PTFE resins adzakhala osakhudzidwa ndi kumizidwa mu aqua regia.Koma ngati kutentha ndi chifukwa cha kuthamanga kwa reagent izi kukhala mkulu, mayamwidwe zigawo zikuluzikulu za reagent mu utomoni nawonso kuwonjezeka.Kusinthasintha kotsatira, monga kutsika kwadzidzidzi kwa kuthamanga, kumatha kuwononga thupi chifukwa chakukula kwa nthunzi yomwe imalowetsedwa mu utomoni.Mwachionekere, ndiye, pamene tikukamba za mankhwala katundu wa PTFE tiyenera kusiyanitsa mosamalitsa zimachitikira mankhwala, monga ife anasonyeza mwa mawu a "Chemical ngakhale" ndi zochita za thupi, monga "mayamwidwe" pamodzi ndi makina ndi matenthedwe nkhawa.
M'nyengo yotentha yomwe imagwiritsidwa ntchito, PTFE resins imakhudzidwa ndi mankhwala ochepa kwambiri m'malo molemba mankhwala omwe amagwirizana nawo.Ma reactants awa ali m'gulu lazinthu zachiwawa komanso zochepetsera zomwe zimadziwika.Elemental sodium polumikizana kwambiri ndi fluorocarbons amachotsa fluorine mu molekyulu ya polima.Izi zimagwiritsidwa ntchito kwambiri mu njira zopanda madzi zopangira PTFE kuti ma resins azikhala omata.Zitsulo zina za alkali (potaziyamu, lithiamu, ndi zina zotero) zimagwiranso ntchito mofananamo.
Nthawi zina kapena pafupi ndi kutentha kwapakati pa 260 ° C kwa TFE & PFA, ndi 204 ° C kwa FEP, mankhwala ochepa omwe ali ochuluka kwambiri adanenedwa kuti akugwira ntchito ku PTFE.Kuukira kofanana ndi sodium etch kwapangidwa pa kutentha kwakukulu kotere ndi 80% NaOH kapena KOH, ma hydrides achitsulo monga boranes (mwachitsanzo, B2H6), aluminium chloride, ammonia (NH3), ndi ma amines (R-NH2) ndi imines ( R = NH).Komanso, kuukira kwapang'onopang'ono kwa okosijeni kwawonedwa ndi 70% nitric acid pansi pa 250 ° C.Kuyezetsa kwapadera kumafunika pamene zovuta zochepetsera kapena zowononga oxidizing zikuyandikira.
Kuyamwa
Mosiyana ndi zitsulo, pulasitiki ndi ma elastomers zimatenga zinthu zosiyanasiyana, makamaka zamadzimadzi.Ma Absorptivities mu PTFE ndi otsika kwambiri, ndipo kachitidwe ka mankhwala pakati pa pulasitiki ndi zinthu zina ndizosowa (kupatulapo zochepa zomwe tazitchula kale).Komabe, mayamwidwe akaphatikizidwa ndi zotsatira zina, katunduyu amatha kukhudza kugwiritsidwa ntchito kwa ma resin awa pamalo enaake amankhwala.Mwachitsanzo, ngati kusinthasintha kwa kutentha kapena kuthamanga kwachangu kumachitika, zinthu zitha kuchitika zomwe zingawononge thupi.Kutentha kwakukulu kwautumiki kwa PTFE resins kumawawonetsa ku mtundu uwu wa kuwonongeka kwa thupi kawirikawiri kuposa mapulasitiki ena.
Mwa kufotokozera, tiyeni tiganizire za mayeso a "steam cycle" omwe akufotokozedwa mumiyezo ya ATSM * yamapaipi okhala ndi mizere.Zitsanzo zamapaipi okhala ndi mizere zimatenthedwa ndi nthunzi ya 0.8MPa (125 psi), kusinthasintha ndi madzi ozizira otsika, zomwe zimapangitsa kusinthasintha kwakukulu kwa kutentha ndi kupanikizika kwenikweni.Izi zikubwerezedwa kwa 100 kuzungulira.Mpweya udapanga kutsika komanso kutentha kwa liner kupangitsa kuyamwa kwa nthunzi kakang'ono komwe kamalowa madzi mkati mwa khoma la liner.Pakutulutsa mphamvu, kapena kuyambitsanso nthunzi, madzi otsekera amatha kuwonjezereka kukhala nthunzi zomwe zimapangitsa kuti pore ikhale yoyambirira.Kuthamanga kobwerezabwereza ndi kuyendetsa njinga zotentha kumakulitsa ma micro pores, pamapeto pake kumayambitsa matuza odzaza ndi madzi mkati mwa liner.Miyezo ya ASTM imazindikira kuti matuza samasokoneza magwiridwe antchito a chitoliro cha chitoliro - makulidwe otchinga mankhwala akadalibe.
Pali njira zowononga zomwe zimachepetsa kuopsa kwa matuza.Kusungunula kwa kutentha kwa chitoliro kapena chotengera chomwe chili ndi mizere kumachepetsa kutentha kwa liner, motero nthawi zambiri kumalepheretsa kusungunuka ndi kukulitsa kwamadzimadzi komwe kumatengera.Zinachepetsanso liwiro ndi kukula kwa kusintha kwa kutentha, motero kumachepetsa matuza.Chifukwa chake, pochepetsa utomoni, kutchinjiriza kumatha kupereka chitetezo nthawi zambiri.Chitetezo chowonjezera chikhoza kuperekedwa pogwiritsa ntchito njira zogwirira ntchito kapena zipangizo zomwe zimachepetsa kuchepetsa kuthamanga kwa ndondomeko kapena kuwonjezeka kwa kutentha.
Permeation
Permeation ndi chinthu chogwirizana kwambiri ndi kuyamwa, koma ndi ntchito ya zotsatira zina zakuthupi, monga kufalikira ndi kutentha.Pazaka zopitilira 20 zokhala ndi chitoliro chokhala ndi mizere ya PTFE, kuchuluka kwa zolephera zomwe zimachitika chifukwa cha kulowerera kwa mpweya wowononga wotsatiridwa ndi dzimbiri kwa membala wothandizira zakhala zochepa kwambiri.Makulidwe a liner a 1.27 mpaka 6.35mm ofunikira kuti akhale ndi mphamvu zolimbitsa thupi pakatentha kwambiri amachepetsa kulowera kotero kuti nthawi zambiri kumakhala kocheperako.Chifukwa mitundu yambiri imakhudza kulowa mkati, ndizosocheretsa kugwiritsa ntchito chidziwitso cha labotale chopezedwa ndi makanema owonda a polima ngati maziko osankha zomangira za polima za fluoroplastic.Kupatulapo pang'ono, kusiyana kwa permeability pakati pa ma fluoroplastics sikukhudzanso magwiridwe antchito a mapaipi opangidwa ndi zida.Kuchita kumayendetsedwa makamaka ndi mapangidwe, kupanga ndi kulamulira khalidwe.Chifukwa chake, chodetsa nkhawa chachikulu nthawi zambiri chimakhala ndi kuyamwa, chifukwa ichi ndiye chinthu chomwe chikuwonetsa kuti utomoni wa fluorocarbon umagwira ntchito m'malo opangidwa ndi mankhwala.
M'miyendo yopanda malire, ndikofunikira kuti danga lapakati pa liner ndi membala wothandizira litulutsidwe mumlengalenga, osati kungopangitsa kuti mpweya utuluke pang'ono komanso kuti mpweya wotsekeka usagwetse chingwecho.Komanso, mpweya uwu umagwiritsidwa ntchito poyesa kuwongolera kwabwino kwa chitoliro chokhala ndi mizere komanso ngati chida chachitetezo chowonetsa kutayikira ngati liner yawonongeka.Kugwa kwa liner nthawi zambiri kumabwera chifukwa cha kulowa mkati pomwe chifukwa chake chachikulu ndikutuluka kwa vacuum mumtsinje.Opanga mizere chitoliro kufalitsa kukana vacuum pa kutentha oveteredwa kukula kwake ndi makulidwe liner, koma nthawi zina kofunika kupewa vacuum mochulukira ndi kapangidwe mbali ndi njira ntchito.
Nthawi yotumiza: Feb-14-2019