Nyob nruab nrab ntawm kev tsim khoom, lub phaj cua sov yuav raug muab tshem tawm nrog methyl ethyl ketone, acetone, lossis lwm yam kuab tshuaj muaj zog kom tshem tawm cov khoom siv polymer thiab cov txheej txheem sib kis. Cov txheej txheej saum npoo yuav tsum tiv taus qhov kev ua phem rov qab ua haujlwm tom qab ua haujlwm yam tsis muaj softening, tev, o, lossis poob kev ua haujlwm.
Chemical Exposure Challenges nyob rau hauv Cua Sov Phaj Ntxuav
Kev tu lub voj voog hauv kev lag luam thermal feem ntau koom nrog cov tshuaj hnyav hnyav tsim los ua kom yaj cov nplaum, resins, thiab cov khoom siv polymer. Cov no tuaj yeem suav nrog ketones, esters, lossis cov kuab tshuaj sib xyaw ua ke siv nyob rau hauv qhov kub thiab txias.
Cov xim txheej txheem, epoxy txheej, lossis hmoov txheej tsis haum rau qhov chaw no. Cov pa coatings feem ntau raug kev txom nyem los ntawm:
Cov kuab tshuaj-induced o
Poob ntawm adhesion ntawm qhov kub thiab txias
Progressive tawg nyob rau hauv thermal cycling
Deg degradation ua rau muaj kev pheej hmoo kis kab mob
Rau kev ua haujlwm ntev -lub sijhawm ua haujlwm, fluoropolymer- cov txheej txheem yog cov kev daws teeb meem tseem ceeb.
Fluoropolymer Txheej raws li cov txheej txheem daws teeb meem
Rauqhia txheej txheej cua sov phaj txhoj puab heev cov kuab tshuaj, fluoropolymer systems xws li PTFE thiab PFA feem ntau yog xaiv vim lawv tshwj xeeb tshuaj inertness.
Cov ntaub ntawv no yog resistant rau:
Ketones (xws li acetone, MEK)
Esters thiab cawv-raws li tshuaj ntxuav
Feem ntau muaj cov kua qaub thiab alkalis
Organic kuab tshuaj tov siv nyob rau hauv polymer ua
Cov txheej yog cov khoom siv tshuaj tua kab mob uas tiv thaiv cov hlau hauv qab ntawm cov khoom siv los ntawm kev rov raug tshuaj lom neeg.
Txawm li cas los xij, qhov tseeb specification yog qhov tseem ceeb. Cov kuab tshuaj muaj pes tsawg leeg thiab kev ntxuav kub yuav tsum tau txhais thaum lub sij hawm tsim, vim tias qhov kub siab tuaj yeem ua rau cov kuab tshuaj nqus tau zoo txawm tias nyob hauv fluoropolymer.
PTFE vs PFA rau Solvent Cleaning Environments
Ob leeg PTFE thiab PFA nthuav tawm dav tshuaj tiv thaiv, tab sis qhov sib txawv ntawm kev ua thiab microstructure cuam tshuam ntev - lub sijhawm ua haujlwm.
PFA feem ntau nyiam nyob rau hauv cov ntawv thov kev ua kom nruj vim nws cov yaj- txheej txheem, uas ua rau cov txheej txheem txheej txheej denser thiab ntau homogeneous. Qhov no txo cov micro-porosity thiab txwv cov kuab tshuaj wicking ntawm txheej txheej.
PTFE coatings tseem muaj txiaj ntsig zoo tab sis tuaj yeem pom me ntsis permeability nyob ntawm daim ntawv thov txoj kev thiab sintering zoo.
Cov txheej txheem xaiv yooj yim siv tau:
Nquag thiab kub hnyav ntxuav → PFA nyiam
Nruab nrab lossis qee zaus kev ntxuav → PTFE tau txais
Adhesion thiab Thermal Cycling Considerations
Txheej kev ua tau zoo tsis yog tswj hwm los ntawm tshuaj lom neeg. Adhesion rau lub hauv paus hlau yog ib qho tseem ceeb, tshwj xeeb tshaj yog nyob rau hauv rov qab thermal expansion thiab contraction cycles thaum lub sij hawm cua sov ua hauj lwm thiab hnyav tu.
Cov ntsiab lus tseem ceeb ntawm kev tsim qauv muaj xws li:
Kev npaj kom zoo (grit blasting lossis tshuaj etching)
Tswj primer systems rau hlau sib txuas
Sib piv thermal expansion yam ntxwv ntawm txheej thiab substrate
Txaus txheej thickness kom tsis txhob tsim pinhole
Yog tias tsis muaj adhesion txaus, txawm tias cov tshuaj tiv thaiv kab mob tuaj yeem ua tsis tiav.
Validation thiab Qualification Testing
Ib qho hnyav so los yog immersion xeem ntawm tus neeg sawv cev coated daim coupon feem ntau yog siv raws li ib tug validation kauj ruam thaum lub sij hawm specification txoj kev loj hlob. Cov kev ntsuam xyuas no simulate tiag tiag tu tej yam kev mob thiab paub meej tias txheej kev ncaj ncees nyob rau hauv ua ke tshuaj lom neeg thiab thermal raug.
Cov neeg tsim khoom feem ntau vam khom cov ntaub ntawv tiv thaiv tshuaj tiv thaiv rau PTFE thiab PFA, tab sis daim ntawv thov -kev ntsuas tshwj xeeb muab kev ntseeg siab ntxiv rau cov kev pabcuam hnyav.
Kev txiav txim siab kev taw qhia rau kev xaiv txheej
Kev xaiv txheej tuaj yeem ua kom yooj yim siv cov txheej txheem -raws li txoj cai:
Yog tias cov kuab tshuaj raug mob me me thiab tsis tshua muaj, PTFE txheej muab kev tiv thaiv txaus
Yog tias cov kuab tshuaj raug nquag, nruj, lossis ua haujlwm ntawm qhov kub siab, PFA txheej yuav tsum tau teev tseg
Txoj hauv kev no ua kom cov txheej txheem durability ua raws li qhov xav tau ntawm kev ua haujlwm tiag tiag es tsis yog cov tshuaj nominal compatibility ib leeg.
Xaus
Cov lus qhia tseeb ntawm cov fluoropolymer txheej rau cov cua sov phaj uas raug cov kuab tshuaj hnyav ua kom ntev - lub sij hawm tiv thaiv, tshuaj tiv thaiv, thiab kev tso tawm ruaj khov. PTFE thiab PFA coatings ob qho tib si muab kev tiv thaiv muaj zog rau kev ntxuav cov kuab tshuaj, tab sis kev xaiv yuav tsum tau ua raws li kev tu ntau zaus thiab qhov kub thiab txias.
Txhawm rau qhia cov txheej txheem txheej txheej txheej txheej txheej txheej hnyav hnyav kom raug, txheej txheem chemistry, thermal tej yam kev mob, thiab txij nkawm yuav tsum tau soj ntsuam ua ke kom ntseeg tau tias kev ua tau zoo ntev -.
Thaum kawg, txheej txheej sawv cev rau kev nqis peev hauv cov cuab yeej siv tau ntev, khaws cia ob qho tib si kev ntseeg siab thiab kev ncaj ncees ntawm qhov chaw thoob plaws tag nrho cov kev pabcuam lub neej ntawm cov cua sov.
