Kutheni ukhetha i-PTFE yamatywina?

PTFE amatywinakunye nezisombululo zokutywina zisetyenziswa kwiimarike zemveli zokutywina ezifana ne-pneumatics kunye ne-hydraulics ngokunjalo nakwi-aerospace, amandla, i-oyile negesi, icandelo lezenzululwazi zobomi nakwinkalo yamandla ahlaziyekayo.

Iimpawu ze-PTFESeals ezenziwe kwi-PTFE (Polytetrafluoroethylene) zisetyenziswa apho ezinye izinto ezininzi zokutywina (ezifana ne-elastomers, iPUR, imathiriyeli yelaphu, njl.njl.) zisilela ukuhlangabezana noluhlu lobushushu obufunekayo, ukuxhathisa kweekhemikhali okanye ukungqubana nokunxiba iimfuno.PTFE yafunyanwa ngengozi Ngowe-1938 nguGqr. Roy J. Plunkett welebhu yaseDu Pont's Jackson eNew Jersey, eUnited States.Ngelixa ephanda iigesi ezinxulumene nezikhenkcezisi eziFluorinated, wafumanisa ukuba isampulu enye eshiywe ngobusuku kwisilinda sogcino olucinezelekileyo iye yaphola ngokuzenzekela kwi-white, waxy solid.Esi siqina singqineke sinokwakheka okukhethekileyo okuneempawu eziphawulekayo.Ulwakhiwo lwemolekyuli ye-PTFE lusekwe kumtyana wekhonkco weeathom zekhabhoni ezingqongwe ngokupheleleyo ziiathom zefluorine.Iibhondi ze-carbon-fluorine ziphakathi kwezona zinamandla ezenzeka kwi-organic compounds.

• Uzinzo lobushushu kuluhlu olubanzi lobushushu: Indawo yokunyibilika ephezulu ye-PTFE (342 °C) kunye neempawu zemorphological zivumela amalungu enziwe kwintlaka ukuba asetyenziswe ngokuqhubekayo kumaqondo obushushu benkonzo ukuya kuthi ga kwi-260 °C.Ngaphezulu kweli qondo lobushushu iipropathi zamalungu zithande ukuhla, nto leyo ebanga ukuguga kobushushu kunye nokonakala kwezinto.I-PTFE isetyenziswa kumaqondo obushushu e-cryogenic ukutywina imidiya ebalulekileyo njenge-nitrogen engamanzi (-196 °C), i-hydrogen engamanzi (-253 °C) kunye ne-helium engamanzi (-269 °C).I-PTFE inesakhono esisodwa sokuxhathisa ukuthotywa kwezinto, ukuguga kobushushu kunye nokuguqulwa kweempawu zomzimba ngexesha lokuhamba ngebhayisikile.
• Ukukhuhlana okuphantsi/ukwazi ukubaleka okomileyo: I-PTFE inowona mlinganiso uphantsi wokukhuhlana kwayo nayiphi na into eqinileyo eyaziwayo.Iyakwazi ukuzithambisa, inika isakhono esiqhubekayo sokubaleka esomileyo kwizicelo zokutywina eziguqukayo.
• Ukuxhathisa okugqithisileyo kweekhemikhali: Amandla ekhonkco le-intra polymer chain bond ye-PTFE akuthintela ukusabela kuninzi lweekhemikhali, ngokwenjenjalo zizenza zingasebenzi ngokwekhemikhali kumaqondo obushushu aphakamileyo kunye noxinzelelo phantse zonke iikhemikhali zamashishini kunye nezinyibilikisi.Kuphela ngamajelo eendaba ambalwa aziwa ngokusabela nge-PTFE: iintsimbi zealkali, ifluorine kunye neekhemikhali ezimbalwa zefluoro ezifana neklorine tri-fluoride kunye neoksijini difluoride.I-PTFE ilungele ukudibana nokutya kwaye iyanelisa iimfuno ze-FDA.

Kucacile ukuba ngokwembono yokutywinwa, ezi mpawu zizodwa zinika i-PTFE izakhono ezidlula ezo ze-elastomeric eziqhelekileyo zokutywinwa.Ezinye iimpawu ezibalaseleyo zezi:

• Isiliphu esincitshisiweyo sokhuni
• Ubomi beshelufu obungenamkhawulo: I-PTFE ayigugi ngokuhamba kwexesha kwaye ayichatshazelwa kukukhanya kwe-ultraviolet.
• Akukho decompression eqhumayo: I-PTFE ayinakuchaphazeleka kwi-saturation ye-high-pressure gas enokwandisa ngamandla kwaye ibangele ukuqhuma kwezinto xa uxinzelelo lususwe ngokukhawuleza.
• Akukho kudumba ngenxa yokufunxa ukufuma.
• Ikhuselekile ukusetyenziswa kwiimeko zevacuum.
• Iimpawu zombane ezigqwesileyo: Amandla aphezulu e-dielectric, i-dielectric ephantsi rhoqo kunye nokumelana nombane ophezulu kakhulu.