Chifukwa Chiyani Sankhani PTFE ya Zisindikizo?

PTFE zisindikizondi njira zosindikizira zimagwiritsidwa ntchito m'misika yosindikizira yachikhalidwe monga ma pneumatics ndi ma hydraulics komanso mumlengalenga, mphamvu, mafuta ndi gasi, gawo la sayansi ya moyo komanso gawo la mphamvu zongowonjezwdwa.

Makhalidwe a PTFESeals opangidwa kuchokera ku PTFE (Polytetrafluoroethylene) amagwiritsidwa ntchito pomwe zida zina zambiri zosindikizira (monga elastomers, PUR, zipangizo za nsalu, ndi zina zotero) zimalephera kukwaniritsa kutentha kofunikira, kukana mankhwala kapena kukangana ndi kuvala zofunika.PTFE inapezeka mwangozi mu 1938 ndi Dr. Roy J. Plunkett wa labotale ya Du Pont's Jackson ku New Jersey, USA.Pofufuza mpweya wokhudzana ndi mafiriji opangidwa ndi fluorinated, adapeza kuti chitsanzo chimodzi chomwe chinasiyidwa usiku wonse mu silinda yosungiramo makina osindikizira chinali chopangidwa ndi polymeri yokha kukhala yoyera, yolimba.Cholimba ichi chinatsimikizira kuti chinali ndi mawonekedwe apadera omwe ali ndi katundu wodabwitsa.The molecularstructure of PTFE imachokera pa mzere wozungulira wa maatomu a carbon omwe ali ozunguliridwa ndi maatomu a fluorine.Zomangira za carbon-fluorine ndi zina mwazomwe zimachitika kwambiri mumagulu achilengedwe.

• Kukhazikika kwa kutentha pamitundu yosiyanasiyana ya kutentha: Malo osungunuka a PTFE (342 °C) ndi mawonekedwe a morphological amalola kuti zigawo zopangidwa kuchokera ku utomoni zizigwiritsidwa ntchito mosalekeza pa kutentha kwautumiki mpaka 260 °C.Pamwamba pa kutenthaku, zinthu zakuthupi zimachepa, zomwe zimapangitsa kuti kutentha kukhale kokalamba komanso kuwonongeka kwa zinthu.PTFE imagwiritsidwa ntchito pa kutentha kwa cryogenic kusindikiza zinthu zovuta kwambiri monga nayitrogeni wamadzi (-196 °C), madzi a haidrojeni (-253 °C) ndi helium yamadzi (-269 °C).PTFE ili ndi kuthekera kwapadera kolimbana ndi kuwonongeka kwa zinthu, kukalamba kwa kutentha ndi kusintha kwa zinthu zakuthupi panthawi ya kutentha kwa njinga.
• Kuthamanga kochepa / kowuma kuthamanga: PTFE ili ndi cholumikizira chotsika kwambiri cha cholimba chilichonse chodziwika.Imakhala ndi mphamvu zodzipaka mafuta, zomwe zimapatsa mphamvu zowuma mosalekeza pamakina osindikiza amphamvu.
• Kwambiri kukana mankhwala: The intra polima unyolo chomangira mphamvu za PTFE kuletsa kuchita ndi mankhwala ambiri, potero kuwapanga mankhwala inert pa kutentha okwera ndi zipsyinjo ndi pafupifupi onse mafakitale mankhwala ndi zosungunulira.Ndi ma TV ochepa okha omwe amadziwika kuti amachitira ndi PTFE: zitsulo za alkali, fluorine ndi mankhwala ochepa a fluoro monga chlorine tri-fluoride ndi oxygen difluoride.PTFE ndiyoyenera kukhudzana ndi chakudya ndipo imakwaniritsa zofunikira za FDA.

Zikuwonekeratu kuti kuchokera kumalo osindikizira, makhalidwe apaderawa amapereka mphamvu za PTFE zomwe zimaposa zida zosindikizira za elastomeric. Zina zodziwika bwino ndi izi:

• Kutsika kwa ndodo
• Moyo wa alumali wopanda malire: PTFE sichimakalamba pakapita nthawi ndipo sichimakhudzidwa ndi kuwala kwa ultraviolet.
• Palibe decompression yophulika: PTFE si atengeke machulukitsidwe wa mkulu-anzanu gasi amene angathe kukulitsa mwachiwawa ndi kuchititsa kuphulika kwa zinthu pamene kuthamanga mwadzidzidzi kuchotsedwa.
• Palibe kutupa chifukwa cha kuyamwa kwa chinyezi.
• Ndi zotetezeka kuti zigwiritsidwe ntchito m'malo opanda vacuum.
• Zabwino kwambiri zamagetsi: Mphamvu yapamwamba ya dielectric, yotsika kwambiri ya dielectric komanso kukana kwambiri kwamagetsi.