(saib cov polymer® PTFE thiab polymer® FEP & PFA Specifications ) PTFE cov khoom siv kho tshuab tsis tshua muaj piv rau lwm cov yas, tab sis nws cov khoom tseem nyob ntawm qhov muaj txiaj ntsig zoo tshaj qhov kub ntau ntawm -100 ° F txog + 400 ° F (- 73 ° C rau 204 ° C).
Yam Khoom Ntawm Polymer® PTFE Fluoropolymer Resins
Kub tiv taus
Kub siab tshaj 77 ° C tsis haum rau cov khoom ntawm feem ntau elastomers thiab plastics, whereas PTFE withstands kub txog li 260 ° C.Txawm tias qis dua 77 ° C, yog tias cov kua qaub corrosive rau cov hlau thiab cov kuab tshuaj organic sib xyaw ua ke, cov ntaub ntawv thiab cov khoom ntawm PTFE feem ntau nyiam vim elastomers thiab lwm yam yas feem ntau tsis muaj kev tiv thaiv rau cov kuab tshuaj o thiab softening.
Tshuaj Inertness
Los ntawm tshuaj inertness, peb txhais tau hais tias PTFE fluorocarbon resins tuaj yeem nyob rau hauv kev sib cuag nrog lwm yam khoom uas tsis muaj tshuaj lom neeg tshwm sim.Feem ntau, PTFE fluorocarbon resins yog tshuaj inert.Txawm li cas los xij, cov lus no, zoo li txhua qhov kev qhia dav dav, yuav tsum tsim nyog yog tias nws yuav tsum ua kom raug.Qhov kev tsim nyog yuav tsis ua rau muaj kev tsis sib haum xeeb, txawm li cas los xij, yog tias ib tug nco ntsoov cov lus tseeb ntawm tus cwj pwm ntawm PTFE resins.
Cov lus piav qhia ib txwm muaj ntawm ntau yam kev sim cov ntaub ntawv tuaj yeem ua yuam kev, vim nws tuaj yeem sib sau ua ke hauv ntau hom kev coj tus cwj pwm "Chemical".Yog tias cov lus piav qhia kom meej, nws yuav tsum paub qhov txawv ntawm cov tshuaj tiv thaiv nruj thiab kev ua ntawm lub cev xws li nqus.Cov lus piav qhia yuav tsum ua kom tus neeg siv coj mus rau hauv tus account qhov kev sib raug zoo ntawm lub cev thiab tshuaj lom neeg uas yuav cuam tshuam rau ib qho kev thov.
Piv txwv li, PTFE resins yuav tsis cuam tshuam los ntawm immersion hauv aqua regia.Txawm li cas los xij, yog tias qhov ntsuas kub thiab qhov tshwm sim siab ntawm cov reagent no dhau los ua siab, qhov nqus ntawm cov khoom ntawm cov reagent mus rau hauv cov resin kuj yuav nce ntxiv.Cov kev hloov pauv tom qab, xws li kev poob siab tam sim ntawd, tuaj yeem ua rau lub cev puas tsuaj vim kev nthuav dav ntawm cov vapors absorbed hauv cov resin.Pom tseeb, tom qab ntawd, thaum peb tham txog cov khoom siv tshuaj lom neeg ntawm PTFE peb yuav tsum paub qhov txawv ntawm cov tshuaj tiv thaiv nruj heev, raws li peb tau hais txog "Chemical compatibility" thiab lub cev ua haujlwm, xws li "kev nqus" ua ke nrog kev siv tshuab thiab thermal.
Nyob rau hauv ib txwm siv kub, PTFE resins raug tawm tsam los ntawm ob peb cov tshuaj es tsis tabulate cov tshuaj uas lawv sib xws.Cov reactants no yog ib qho ntawm cov oxidizers hnyav tshaj plaws thiab txo cov neeg ua haujlwm paub.Elemental sodium nyob rau hauv kev sib cuag nrog fluorocarbons tshem tawm fluorine los ntawm polymer molecule.Cov tshuaj tiv thaiv no yog siv dav hauv cov tshuaj anhydrous rau etch qhov chaw ntawm PTFE kom cov resins tuaj yeem ua cov nplaum nplaum.Lwm cov alkali hlau (potassium, lithium, thiab lwm yam) hnov zoo li no.
Qee qhov xwm txheej ntawm lossis ze ntawm qhov kev pom zoo txwv qhov ntsuas kub ntawm 260 ° C rau TFE & PFA, thiab 204 ° C rau FEP, ob peb cov tshuaj nyob rau hauv siab tau tshaj tawm cov tshuaj tiv thaiv rau PTFE.Kev tawm tsam zoo ib yam li sodium etch tau raug tsim los ntawm qhov kub siab ntawm 80% NaOH lossis KOH, hlau hydrides xws li boranes (xws li, B2H6), aluminium chloride, ammonia (NH3), thiab qee yam amines (R-NH2) thiab imines ( R = NH).Tsis tas li ntawd, qeeb oxidative nres tau pom los ntawm 70% nitric acid nyob rau hauv siab ntawm 250 ° C.Kev ntsuam xyuas tshwj xeeb yog xav tau thaum muaj kev txo qis lossis oxidizing tej yam kev mob mus txog.
Kev nqus
Hauv kev sib piv rau cov hlau, yas thiab elastomers nqus ntau qhov sib txawv ntawm cov ntaub ntawv uas lawv hu, tshwj xeeb tshaj yog cov kua organic.Absorptivities nyob rau hauv PTFE tsis tshua muaj tsawg, thiab tshuaj lom neeg cov tshuaj tiv thaiv ntawm cov yas thiab lwm yam tshuaj yog ib tug tsis tshua muaj (nrog rau ob peb qhov tshwj xeeb sau tseg yav dhau los).Txawm li cas los xij, thaum nqus tau nrog lwm cov teebmeem, cov cuab yeej no tuaj yeem cuam tshuam cov kev pabcuam ntawm cov resins hauv ib cheeb tsam tshuaj lom neeg.Piv txwv li, yog tias muaj kev hloov pauv sai hauv qhov kub thiab txias, qhov xwm txheej yuav raug tsim ua rau lub cev puas tsuaj.Qhov kev pabcuam dav dav rau PTFE resins nthuav tawm lawv rau hom kev puas tsuaj ntawm lub cev ntau dua li lwm cov yas.
Los ntawm txoj kev piav qhia, cia peb xav txog qhov "steam cycle" test piav nyob rau hauv ATSM cov qauv * rau kab yeeb nkab.Cov qauv ntawm cov yeeb nkab kab yog raug rau 0.8MPa (125 psi) chav, hloov nrog cov dej txias txias, ua rau muaj qhov kub thiab txias heev.Qhov no rov ua dua rau 100 lub voj voog.Chav tsim ib lub siab thiab kub gradient los ntawm lub liner ua rau nqus ntawm ib tug me me ntawm cov chav uas condenses rau dej nyob rau hauv lub liner phab ntsa.Thaum lub siab tso tawm, los yog nyob rau hauv reintroduction ntawm chav, cov dej entrapped yuav nthuav mus vapor ua ib tug thawj micro pore.Kev rov ua kom lub siab thiab thermal cycling ua kom lub micro pores, thaum kawg ua rau pom cov hlwv uas muaj dej puv hauv liner.Cov txheej txheem ASTM nco ntsoov tias cov hlwv tsis cuam tshuam rau cov yeeb nkab liner kev ua tau zoo - cov tshuaj tiv thaiv cov thickness tseem zoo li qub.
Muaj cov kev ntsuas corrosive uas txo qhov hnyav ntawm blistering.Thermal rwb thaiv tsev ntawm ib tug lined yeeb nkab los yog hlab ntsha txo qhov kub ntawm gradient nyob rau hauv lub liner, yog li feem ntau tiv thaiv condensation thiab tom ntej expansion ntawm absorbed kua.Nws kuj txo qhov ceev thiab qhov loj ntawm qhov kub thiab txias hloov, yog li txo qis blistering.Yog li, los ntawm kev txo cov resin, rwb thaiv tsev tuaj yeem muab kev tiv thaiv kev tiv thaiv hauv ntau qhov xwm txheej.Kev tiv thaiv ntxiv tuaj yeem muab los ntawm kev siv cov txheej txheem kev khiav hauj lwm lossis cov cuab yeej siv uas txwv tus nqi ntawm cov txheej txheem kev txo qis lossis kub nce.
Permeation
Permeation yog qhov cuam tshuam zoo rau kev nqus, tab sis nws kuj yog ib qho kev ua haujlwm ntawm lwm yam kev cuam tshuam ntawm lub cev, xws li diffusion thiab kub.Nyob rau hauv ntau tshaj 20 xyoo ntawm kev paub nrog PTFE lined yeeb nkab, tus naj npawb ntawm cov tsis ua hauj lwm los ntawm permeation ntawm ib tug corrosive vapor tom qab corrosion ntawm cov neeg txhawb nqa tau zoo kawg li ob peb.Lub liner thicknesses ntawm 1.27 mus rau 6.35mm tsim nyog rau lub cev muaj zog ntawm qhov kub thiab txias txo permeation mus rau lub ntsiab lus uas nws yog ib qho kev txiav txim siab me me.Vim tias muaj ntau qhov sib txawv cuam tshuam rau permeation, nws yog qhov yuam kev los siv cov ntaub ntawv kuaj permeability tau nrog cov ntaub ntawv nyias nyias ua lub hauv paus rau kev xaiv cov fluoroplastic polymer linings.Muaj qee qhov tshwj xeeb, qhov sib txawv ntawm permeability ntawm fluoroplastics muaj qhov cuam tshuam me me ntawm kev ua haujlwm ntawm cov kav dej thiab cov khoom siv.Kev ua tau zoo yog tswj feem ntau los ntawm kev tsim, fabrication thiab kev tswj kom zoo.Yog li, qhov kev txhawj xeeb tseem ceeb yog feem ntau nrog kev nqus, vim qhov no yog cov cuab yeej tshaj plaws qhia txog kev pabcuam ntawm fluorocarbon resins hauv ib puag ncig tshuaj.
Nyob rau hauv cov ntaub ntawv uas tsis muaj bounded, nws yog ib qho tseem ceeb uas qhov chaw nruab nrab ntawm liner thiab cov neeg txhawb nqa yuav tsum tau vented rau cov huab cua, tsis tsuas yog tso cai rau kev khiav tawm ntawm feeb kom muaj nuj nqis ntawm permeant vapors tab sis tiv thaiv kev nthuav dav ntawm huab cua nkag los ntawm kev sib tsoo lub liner.Tsis tas li ntawd, cov vents no yog siv rau kev tswj xyuas zoo ntawm cov yeeb nkab kab thiab ua cov cuab yeej kev nyab xeeb los qhia txog kev xau nyob rau hauv cov ntaub ntawv puas.Lub cev qhuav dej feem ntau yog vim qhov permeation thaum qhov tseeb qhov ua rau yog qhov tshwm sim ntawm lub tshuab nqus tsev hauv cov txheej txheem kwj.Cov neeg tsim khoom ntawm cov kab yeeb nkab luam tawm qhov kev tawm tsam rau lub tshuab nqus tsev ntawm qhov ntsuas kub ntawm lawv qhov sib txawv thiab cov thicknesses, tab sis qee zaum nws yog ib qho tsim nyog los tiv thaiv lub tshuab nqus tsev ntau dhau los ntawm cov qauv tsim thiab cov txheej txheem ua haujlwm.
Post lub sij hawm: Feb-14-2019