Kungani Khetha i-PTFE Yezimpawu?

Izimpawu ze-PTFEkanye nezixazululo zokuvala zisetshenziswa ezimakethe zokuvala ezivamile ezifana ne-pneumatics kanye ne-hydraulics kanye nasemkhathini, amandla, uwoyela negesi, umkhakha wesayensi yezempilo kanye nasemkhakheni wamandla avuselelekayo.

Izimpawu ze-PTFESeals ezenziwe nge-PTFE (Polytetrafluoroethylene) zisetshenziswa lapho ezinye izinto eziningi zokuvala (njengama-elastomers, i-PUR, izinto zendwangu, njll.) zihluleka ukuhlangabezana nebanga lokushisa elidingekayo, ukumelana namakhemikhali noma izimfuneko zokungqubuzana nokuguga.I-PTFE itholwe ngengozi 1938 nguDkt. Roy J. Plunkett welabhorethri kaDu Pont's Jackson eNew Jersey, eU.SA.Ngenkathi ephenya amagesi ahlobene neziqandisi ezine-fluorinated, wathola ukuthi isampula eyodwa eshiywe ngobusuku kusilinda esinomshini wokulondoloza i-polymerised ngokuzenzakalelayo ukuze kube okuqinile okumhlophe, oku-waxy.Lokhu okuqinile kubonakale kunokwakheka okuyingqayizivele okunezici eziphawulekayo.I-molecularstructure ye-PTFE isekelwe ochungechungeni lwama-athomu e-carbon azungezwe ngokuphelele ama-athomu e-fluorine.Amabhondi e-carbon-fluorine aphakathi kwezinto ezinamandla kakhulu ezenzeka kuma-organic compounds.

• Ukuzinza kwe-thermal ebangeni elibanzi lokushisa: Iphoyinti lokuncibilika eliphakeme le-PTFE (342 °C) nezici ze-morphological zivumela izingxenye ezenziwe ngenhlaka ukuthi zisetshenziswe ngokuqhubekayo emazingeni okushisa esevisi afika ku-260 °C.Ngaphezu kwaleli zinga lokushisa izinto ezibonakalayo zezingxenye zivame ukuncipha, okubangela ukuguga kokushisa kanye nokuwohloka kwempahla.I-PTFE isetshenziswa emazingeni okushisa e-cryogenic ukuvala imidiya ebucayi njenge-nitrogen ewuketshezi (-196 °C), i-hydrogen enguketshezi (-253 °C) ne-helium ewuketshezi (-269 °C).I-PTFE inekhono eliyingqayizivele lokumelana nokuwohloka kwezinto, ukuguga kokushisa nokuguqulwa kwezinto ezibonakalayo ngesikhathi sokuhamba ngebhayisikili.
• Ukungqubuzana okuphansi/ikhono lokugijima elomile: I-PTFE ine-coefficient ephansi yokungqubuzana kwanoma yikuphi okuqinile okwaziwayo.Inamandla okuzithambisa, enikeza ikhono eliqhubekayo lokugijima elomile ezinhlelweni zokuvala eziguquguqukayo.
• Ukumelana namakhemikhali okwedlulele: Amandla ebhondi ye-intra polymer chain ye-PTFE avimbela ukusabela ngamakhemikhali amaningi, ngaleyo ndlela awenze angangeni ngamakhemikhali emazingeni okushisa aphakeme nezingcindezi cishe nawo wonke amakhemikhali nezinyibilikisi zezimboni.Imidiya embalwa kuphela eyaziwa ngokusabela nge-PTFE: izinsimbi ze-alkali, i-fluorine namakhemikhali e-fluoro ambalwa njenge-chlorine tri-fluoride ne-oxygen difluoride.I-PTFE ifanele ukuxhumana nokudla futhi yanelisa izidingo ze-FDA.

Kuyacaca ukuthi ngokombono wokuvala, lezi zici eziyingqayizivele zinikeza i-PTFE amandla adlula lawo wezinto ezivamile zokuvala i-elastomeric.Ezinye izici ezivelele yilezi:

• I-stick-slip encishisiwe
• Impilo yeshelufu engenamkhawulo: I-PTFE ayigugi ngokuhamba kwesikhathi futhi ayithintwa ukukhanya kwe-ultraviolet.
• Akukho ukuwohloka kokuqhuma: I-PTFE ayingenwa kalula ukugcwaliswa kwegesi enomfutho ophezulu ongakhula ngamandla futhi ibangele ukuqhuma kwezinto lapho ingcindezi isuswa kungazelelwe.
• Akukho ukuvuvukala ngenxa yokumuncwa komswakama.
• Iphephile ukusetshenziswa ezimeni ze-vacuum.
• Izakhiwo zikagesi ezinhle kakhulu: Amandla aphezulu e-dielectric, i-dielectric engaguquki ephansi kanye nokumelana nogesi okuphakeme kakhulu.