( bheka futhi i-polymer® PTFE kanye ne-polymer® FEP & PFA Specifications ) Izakhiwo zemishini ye-PTFE ziphansi uma ziqhathaniswa namanye amapulasitiki, kodwa izici zayo zihlala zisezingeni eliwusizo phezu kwezinga lokushisa elibanzi lika -100°F kuya ku-+400°F (- - 73°C kuya ku-204°C).
Izakhiwo Ezivamile ze-polymer® PTFE Fluoropolymer Resins
Ukumelana nezinga lokushisa
Amazinga okushisa angaphezu kuka-77°C awahambisani nezingxenye zama-elastomer amaningi namapulasitiki, kuyilapho i-PTFE imelana namazinga okushisa afinyelela ku-260°C.Ngisho nangaphansi kuka-77°C, uma ama-asidi agqwala ezinsimbini nasezincibilikisini eziphilayo kuhlangene, amalayini nezingxenye ze-PTFE kuvame ukuthandwa ngenxa yokuthi ama-elastomer namanye amapulasitiki avame ukuntula ukumelana nokuvuvukala kwe-solvent kanye nokuthamba.
Ukungangeni Kwamakhemikhali
Ngokungangeni kweKhemikhali, sisho ukuthi ama-PTFE Fluorocarbon resins angaba ukuxhumana okuqhubekayo nenye into ngaphandle kokusabela kwamakhemikhali okutholakala okwenzekayo.Ngokuvamile, i-PTFE fluorocarbon resins ayisebenzi ngamakhemikhali.Noma kunjalo, lesi sitatimende, njengawo wonke ama-generalizations, kufanele sifaneleke uma sizonemba ngokuphelele.Iziqu ngeke ziholele ekudidekeni, noma kunjalo, uma umuntu egcina engqondweni amaqiniso ayisisekelo mayelana nokuziphatha kwe-PTFE resins.
Isifinyezo esijwayelekile sencazelo yedatha yokuhlola ehlukahlukene singase sidukise, ngoba singase sihlangane ngokuyisisekelo izinhlobo ezihlukene zokuziphatha "Kwekhemikhali".Uma incazelo izoba sobala, kufanele ihlukanise phakathi kokusabela kwamakhemikhali ngokuqinile kanye nezenzo zomzimba njengokumuncwa.Incazelo kufanele ivumele umsebenzisi ukuthi acabangele ukuhlobana kwezakhiwo zomzimba namakhemikhali okungase kuthinte uhlelo oluthile.
Isibonelo, ama-PTFE resins ngeke athintwe ukucwiliswa ku-aqua regia.Kodwa uma izinga lokushisa kanye nokucindezela okuwumphumela kwalesi siphepho kuba phezulu, ukumuncwa kwezingxenye ze-reagent ku-resin nakho kuzokwanda.Ukushintshashintsha okulandelayo, njengokuncipha kwengcindezi kungazelelwe, kungase kube yingozi emzimbeni ngenxa yokwanda kwezihwamuko ezimuncwe kunhlaka.Ngokusobala-ke, uma sikhuluma ngezakhiwo zamakhemikhali ze-PTFE kufanele sihlukanise phakathi kokusabela kwamakhemikhali ngokuqinile, njengoba sizwakalise “ngokuhambisana kwamakhemikhali” nezenzo zomzimba, njengokuthi “ukumuncwa” kuhlanganiswe nokucindezeleka kwemishini nokushisa.
Ngaphakathi kwamazinga okushisa okusetshenziswa okuvamile, ama-resin e-PTFE ahlaselwa amakhemikhali ambalwa kunokuba adwebe amakhemikhali ahambisana nawo.Lawa ma-reactants aphakathi kwama-oxidizer anodlame kakhulu nama-ejenti anciphisayo aziwayo.I-sodium ye-elemental ekuxhumaneni okuseduze nama-fluorocarbons isusa i-fluorine ku-molecule ye-polymer.Lokhu kusabela kusetshenziswa kakhulu ezixazululweni ezingenamanzi ukuze kuqoshwe indawo engaphezulu ye-PTFE ukuze ama-resin akwazi ukunamathela.Ezinye izinsimbi ze-alkali (i-potassium, i-lithium, njll.) zenza ngendlela efanayo.
Kwezinye izimo at noma eduze kwamazinga okushisa omkhawulo wesevisi ophakanyisiwe angu-260°C we-TFE & PFA, kanye no-204°C we-FEP, amakhemikhali ambalwa ekugxilweni okuphezulu abikwe asebenza ku-PTFE.Ukuhlasela okufana ne-sodium etch kuye kwakhiqizwa emazingeni okushisa aphezulu kangaka ngo-80% we-NaOH noma i-KOH, ama-hydrides ensimbi afana ne-boranes (isb, i-B2H6), i-aluminium chloride, i-ammonia (NH3), kanye nama-amine athile (R-NH2) kanye nemines ( R = NH).Futhi, ukuhlasela okuhamba kancane kwe-oxidative kuye kwabonwa ngu-70% we-nitric acid ngaphansi kwengcindezi engu-250°C.Ukuhlolwa okukhethekile kuyadingeka lapho izimo ezinjalo ezeqisayo zokunciphisa noma ze-oxidizing kusondela.
Ukumuncwa
Ngokuphambene nezinsimbi, ipulasitiki nama-elastomer amunca amanani ahlukahlukene ezinto ezithintana nawo, ikakhulukazi uketshezi lwemvelo.Ama-Absorptivities ku-PTFE aphansi ngokungavamile, futhi ukusabela kwamakhemikhali phakathi kwepulasitiki nezinye izinto kuyivelakancane (ngaphandle kokumbalwa okuphawulwe ngaphambilini).Kodwa-ke, lapho ukumuncwa kuhlanganiswa neminye imiphumela, le ndawo ingaba nomthelela ekusebenzeni kwalezi zinsalela endaweni ethile yamakhemikhali.Isibonelo, uma ukushintshashintsha okusheshayo kwezinga lokushisa noma ukucindezela kwenzeka, izimo zingase zidalwe ezilimaza umzimba.Ibanga lokushisa elibanzi lesevisi le-PTFE resins libadalula kulolu hlobo lokulimala ngokomzimba kaningi kunamanye amapulasitiki.
Ngendlela yencazelo, ake sicabangele ukuhlolwa "kwe-steam cycle" okuchazwe kumazinga we-ATSM* wepayipi elilayishiwe.Amasampula amapayipi afakwe ulayini angaphansi kwesitimu esingu-0.8MPa (125 psi), ashintshana namanzi abandayo anengcindezi ephansi, okubangela ukushintshashintsha okukhulu kokushisa nokucindezela ngempela.Lokhu kuyaphindwa imijikelezo eyi-100.I-Steam idale umfutho kanye ne-gradient yezinga lokushisa nge-liner ebangela ukumuncwa kwenani elincane lesitimu esijiya sibe amanzi ngaphakathi kodonga lwe-liner.Ekudedelweni kwengcindezi, noma lapho kufakwa kabusha isitimu, amanzi avalelwe anganwebeka abe umhwamuko abangele imbotshana yasekuqaleni.Ukucindezela okuphindaphindiwe kanye nokuhamba ngebhayisikili okushisayo kwandisa ama-micro pores, ekugcineni kubangele amabhamuza agcwele amanzi abonakalayo ngaphakathi kwe-liner.Izindinganiso ze-ASTM ziphawula ukuthi ama-blister awathinti kabi ukusebenza kwe-pipe liner - ugqinsi lwesithiyo samakhemikhali lusamile.
Kunezinyathelo ezonakalisayo ezinciphisa ubunzima bokuqhunyiswa kwamabhamuza.Ukushisa okushisayo kwepayipi elifakwe ulayini noma umkhumbi kunciphisa izinga lokushisa ku-liner, ngaleyo ndlela kuvame ukuvimbela ukujiya kanye nokwanda okulandelanayo koketshezi olumuncwayo.Iphinde yehlisa isivinini kanye nobukhulu bokushintsha kwezinga lokushisa, ngaleyo ndlela kunciphisa amabhamuza.Ngakho-ke, ngokunciphisa i-resin, ukwahlukanisa kunganikeza isilinganiso sokuzivikela ezimweni eziningi.Ukuvikelwa okwengeziwe kunganikezwa ngokusebenzisa izinqubo zokusebenza noma amadivayisi akhawulela izinga lokunciphisa ingcindezi yenqubo noma ukunyuka kwezinga lokushisa.
I-Permeation
I-Permeation iyisici esihlobene eduze nokumunca, kodwa futhi kungumsebenzi weminye imiphumela engokomzimba, njengokusatshalaliswa kanye nezinga lokushisa.Ngaphezulu kweminyaka engama-20 yesipiliyoni ngepayipi elilayishiwe le-PTFE, inani lokwehluleka okudalwe ukugcwala komhwamuko ogqwalayo okulandelwa ukugqwala kwelungu losekelo libe limbalwa ngokuphawulekayo.Ubukhulu belayini obungu-1.27 kuya ku-6.35mm obudingekayo ukuze kube namandla ngokomzimba emazingeni okushisa aphezulu bunciphisa ukungena kuze kufike ezingeni lokuthi ngokuvamile kube ukucatshangelwa okuncane.Ngenxa yokuthi izinto eziningi eziguquguqukayo zithinta ukungena, kuyadukisa ukusebenzisa idatha yaselabhorethri yokungena etholwe ngamafilimu amancanyana e-polymer njengesisekelo sokukhethwa kwezingqimba ezithile ze-polymer ze-fluoroplastic.Ngaphandle kokumbalwa, umehluko ekungeneni phakathi kwama-fluoroplastic anomthelela omncane ekusebenzeni kwamapayipi akhiwe nezinto zokusebenza.Ukusebenza kulawulwa ngokuyinhloko ngokuklama, ukwenziwa kanye nokulawulwa kwekhwalithi.Ngakho-ke, ukukhathazeka okuyinhloko kuvamise ukumuncwa, njengoba lokhu kuyinkomba enkulu yokusebenza kwezinsalela ze-fluorocarbon endaweni yamakhemikhali enikeziwe.
Kumalayini angenamkhawulo, kubalulekile ukuthi isikhala esiphakathi kolayini nelungu losekelo singene emoyeni, hhayi nje ukuvumela ukuphuma kwenani elincane lomhwamuko ongapheli kodwa ukuvimbela ukunwetshwa komoya ovaleleke ekubhidlikeni ulayini.Futhi, lezi zintuba zisetshenziselwa ukuhlolwa kokulawulwa kwekhwalithi yepayipi elilayishiwe nanjengethuluzi lokuphepha elibonisa ukuvuza uma kwenzeka umonakalo wolayini.Ukugoqeka kolayini kuvame ukubangelwa ukugcwala kuyilapho empeleni imbangela eyinhloko kuwukwenzeka kwevacuum ekusakazeni kwenqubo.Abakhiqizi bamapayipi anemigqa bashicilela ukumelana ne-vacuum ekushiseni okulinganiselwe kwamasayizi abo ahlukene kanye nobukhulu bamalayini, kodwa ngezinye izikhathi kuyadingeka ukuvimbela i-vacuum ngokweqile ngezici zokuklama nezinqubo zokusebenza.
Isikhathi sokuthumela: Feb-14-2019