Kwa zaka zingapo ma fluoropolymers akhala akugwira ntchito yofunika kwambiri m'mafakitale am'mafakitale ndi ofanana kuti ateteze mbewu ndi zida kuti zisawukidwe ndi mankhwala ndi zida zambiri zaukali.Izi zili choncho chifukwa amapereka mphamvu yabwino kwambiri yolimbana ndi mankhwala komanso kukhazikika kwa kutentha kusiyana ndi mapulasitiki ena kapena zipangizo za elastomeric. media.Izi ndichifukwa choti amapereka kukana kwamankhwala kwabwinoko komanso kukhazikika kwamafuta kuposa mapulasitiki ena kapena zida za elastomeric.
Kutsatira chitukuko cha PTFE, kuyambitsidwa kwa melt-processable fluorinated ethylene-propylene (FEP) mu 1960 kunatsegula malo atsopano ogwiritsira ntchito.PFA, perfluoro-alkoxy polima yomwe yakhala ikugwiritsidwa ntchito bwino kwa zaka 20 ngati zida zomangira, tsopano yalowa m'malo mwa thermoplastic ku PTFE, yokhala ndi mphamvu yofananira yamafuta ndi mankhwala komanso zinthu zapamwamba pokhudzana ndi processor, translucency, permeation resistance ndi mphamvu zamakina. .
M'makampani opanga mankhwala, ma fluoropolymers - PTFE ndi PFA - amagwiritsidwa ntchito makamaka ngati mawonekedwe a linings.Kwa mawonekedwe osavuta, monga mapaipi, ma bend, T-zidutswa kapena zochepetsera, PTFE imagwiritsidwa ntchito;Amagwiritsidwa ntchito ndi phala extrusion, ram extrusion kapena tepi winding.Munjira izi chisanadze mawonekedwe amapangidwa ndi PTFE;Izi ndiye sintered ndi anaikapo mu zitsulo workpiece.Kugwiritsira ntchito PTFE pazitsulo zazitsulo za mawonekedwe ovuta, monga mavavu ndi mapampu, ndizovuta kwambiri.Isostatic akamaumba ndiye njira yokondedwa.Mu PTFE ufa uwu umadzazidwa mu malo omwe amapangidwa pakati pa zitsulo zogwirira ntchito ndi thumba la raba lomwe limapangidwa mwapadera kuti ligwirizane ndi mawonekedwe a malo omwe akuyenera kukhala.Ufawo umakanikizidwa kale, kenako kuzizira mu mawonekedwe omwe mukufuna.Pomaliza, thumba labalali limachotsedwa ndipo gawo lomwe lili pamzere limawotchedwa mu uvuni wopitilira 360?C (680?F).
PFA, chinthu cha thermoplastic chomwe chili ndi malo osungunuka odziwika bwino, amatha kusinthidwa pogwiritsa ntchito kusamutsa akamaumba kapena jekeseni.Granulate imasungunuka mumphika wosungunuka kapena mu extruder ndiyeno amakakamizika kulowa mu chida chotentha ndi makina osindikizira a hydraulic.
Njira imeneyi imathandiza kuti makulidwe a khoma akwaniritsidwe, ndi kulolerana kwa ?0,5 mm, ngakhale pama radiyo olimba komanso m'njira zotsika.Pafupifupi palibe kumaliza kumangofunika, kupatula kuchotsa sprue ndi kusalaza nkhope za ma flanges.
Pogwiritsa ntchito isostatic akamaumba, komabe, kuchuluka kwa mawotchi kumafunika - malingana ndi kuchuluka kwa zovuta za mawonekedwe oti mudzaze - kuti mukwaniritse miyeso yomwe mukufunayo molondola.
Kufanana kwa makulidwe a khoma kumatha kusiyanasiyana, makamaka pankhani ya mawonekedwe ovuta kwambiri monga ma valve housings.
Mayamwidwe ndi Permeation
Mosiyana ndi zitsulo, mapulasitiki ndi ma elastomers amatenga zinthu zosiyanasiyana zomwe amakumana nazo.Izi nthawi zambiri zimakhala ndi ma organic compounds.Mayamwidwe amatha kutsatiridwa ndi kulowa mkati mwa khoma.Ngakhale izi sizimawonedwa kawirikawiri ndi ma fluoropolymers, zimatha kuthana ndi kuchuluka kwa makulidwe a khoma kapena kukhazikitsa zida kuti zithe danga pakati pa mzere wa fluoropolymer ndi khoma lachitsulo.Zasonyezedwa momveka bwino kuti ponena za kulowetsa ndi kuyamwa, ma fluoropolymers osungunuka osungunuka monga PFA amasonyeza bwino zotchinga katundu kuposa PTFE.
Kukaniza Vacuum
Kukana kwa vacuum kumafunika chifukwa, m'makina otsekedwa amtundu womwe amagwiritsidwa ntchito kwambiri pokonza mankhwala, kutsika kwa kutentha kumapangitsa kuti pakhale phokoso mu dongosolo, pokhapokha ngati likugwira ntchito kale pansi pa mphamvu ya mlengalenga.Mukamagwiritsa ntchito PFA ndizosavuta kupeza kukana kokwanira kwa vacuum pazitsulo.Nthawi zambiri chinsalucho chimakhala ?chozikika?ku khoma lachitsulo pogwiritsa ntchito ?mchira wa nkhunda?mikwingwirima kapena mikwingwirima mu
pambuyo pake.
Ndi PTFE granulate yomwe yakhala yozizira- inapangidwa, zimakhala zovuta kuti mukwaniritse phokoso lokhazikika lazitsulo mu khoma lachitsulo monga njira zazikulu zomwe zingafunikire kuti PTFE ufa ulowe mu grooves.Nthawi zambiri, zomangira zimagwiritsidwa ntchito pakati pa PTFE ndi nyumba zachitsulo.Komabe, chifukwa cha zotsutsana ndi zomatira za fluoropolymers komanso kukana kwamafuta pang'ono kwa othandizira omangira, PTFE imangowonetsa kukana kwa vacuum.
Kuwongolera Kwabwino kumalepheretsa Cracks ndi Voids
Ndi PTFE ndi PFA linings, mphamvu ya dielectric imayesedwa kuti izindikire zolakwika.Njirayi imatsimikizira modalirika ming'alu ndi ma voids omwe amapita kuzinthu zonse, koma, chifukwa chapamwamba chodziwika bwino cha resistivity cha fluoropolymers, sichisonyeza zolakwika zomwe zimayambira 1,5 mm kapena kuposa pansi (mkuyu 5). .
Pachifukwa ichi, mayesero enanso pogwiritsa ntchito njira za akupanga angagwiritsidwenso ntchito.Mayesowa amayesa mtunda kuchokera pamwamba pa chinsalu kupita ku nyumba yachitsulo.Komabe, ndizosadalirika chifukwa sizimapereka makulidwe enieni a kansalu pamene pali chopanda kanthu kapena porosity.Kuphatikiza apo, njirayi ndiyosatheka kugwiritsa ntchito tizigawo ting'onoting'ono kapena tinthu tating'ono tating'ono tating'ono tating'ono tating'ono ndi ma radiyo olimba.
Njira ina yowonera zolakwika zapamtunda monga ming'alu ndi voids ndiyotchedwa ?Met-L-Check?njira yolowetsa utoto.Koma njirayi ndi yongozindikira zolakwika zapamtunda zokha.
Kapangidwe ka Chemical
PFA, yomwe imakhala yowoneka bwino, imatha kuyang'aniridwa bwino.Ming'alu ndi ma voids pansi pamadzi amatha kuwoneka ndi magwero oyenera owunikira.Malo omwe safikirikako pang'onopang'ono amatha kuwunika pogwiritsa ntchito nyali zoziziritsa komanso zowongolera zama fiber.
Kuyerekeza kwa Mtengo wa Linings
Pankhani yamitengo yamafuta, PFA imawononga pafupifupi katatu kuposa PTFE.
Kuipa kumeneku kungathe, komabe, kulipidwa kapena kuchepetsedwa kwambiri, monga ntchito ya zinthu monga mawonekedwe oti apangidwe, kukula kwake, chiwerengero cha workpieces kuti apangidwe ndi njira yopangira.Izi ndizotheka chifukwa PFA sifunikira kukonzekera kwapamanja kapena kumaliza kukonza ndi kutayika kwazinthu zofananira.
Kugwiritsiridwa ntchito kwa PFA pakuyika mbali zazikulu kwambiri sikuvomerezedwa, chifukwa kukwera mtengo kwazinthu kungapangitse gawolo kukhala lokwera mtengo kwambiri.Mfundo ina yomwe iyenera kukumbukiridwa ndi mtengo wa zida, zomwe sizilipiridwa
pamene zigawo zing'onozing'ono zokha ziyenera kuikidwa pamzere.Komanso, pali malire othandiza kulemera kwa zinthu jekeseni kuti akamaumba makina amatha kugwira.
Mapeto
Zaka zoposa 20 zokhala ndi zomangira zamagulu osiyanasiyana, mwachitsanzo, ma valve ndi mapampu, zasonyeza kuti PFA ili ndi ubwino wambiri pamene kutentha kwakukulu ndi kukana kwa mankhwala ndizofunikira kwambiri.
Zolondola komanso makulidwe a khoma omwe angapezeke ndi PFA ndi mwayi waukulu, makamaka mukamagwira ntchito ndi media omwe amakonda kufalikira.
Zochitika zothandiza zawonetsanso kuti PFA imapereka zotchinga zabwinoko kuposa PTFE.
Opanga bromine amafotokoza, mwachitsanzo, kuti kuya kwa bromine ku PFA kuli pafupifupi gawo limodzi mwa magawo atatu aliwonse kuposa PTFE, pamene zinthu zogwirira ntchito monga nthawi, kutentha ndi kupanikizika ndizofanana.
PTFE, kumbali ina, imagwiritsidwabe ntchito kwambiri pazigawo za mavavu am'madzi ndi zida zina zopangira mankhwala komwe kumafunikira kukana kutopa.
Zitsanzo zodziwika bwino za ntchito zoterezi ndi mavuvu, komanso ma diaphragms mu mavavu ndi mapampu.
Kwa mphete zapampando, mapulagi, zisindikizo ndi magawo ofanana, PTFE ndizinthu zoyenera komanso zachuma.
Zomwe zachitika posachedwa pamagawo ngati awa ndikugwiritsa ntchito PTFE yosinthidwa, chifukwa kukhazikika kwake ndi kuuma kwake kumaposa za PTFE.
Tags:PTFE,PFA,PTFE vs PFA
Nthawi yotumiza: Apr-01-2017