Pure PTFE tau ua haujlwm rau kev lag luam zoo rau ntau xyoo lawm, tab sis nws qhov kev pabcuam siab tshaj plaws ntawm 110 degrees Celsius thiab tsis tshua muaj zog txhua yam ua rau muaj kev txwv tsim. Cov khoom siv fluoropolymer tshiab thiab cov ntaub ntawv sib xyaw yog thawb cov ciam teb no, nthuav dav qhov twg PTFE-style heaters tuaj yeem xa mus. Cov ntaub ntawv tshawb fawb tau nce qib yog cov kev xaiv uas khaws cov tshuaj inertness thaum muab cov thermal stability ntau dua, zoo dua cov qauv kev ntseeg siab, thiab txhim kho thermal conductivity.
Cov Kev txwv ntawm Unmodified PTFE nyob rau hauv daim ntawv thov cua sov
PTFE (polytetrafluoroethylene) yog khoom plig rau ze rau - tshuaj tiv thaiv universal thiab tsis yog - nplaum nto. Txawm li cas los xij, nws qhov ntsuas kub tsis tu ncua ntawm lub qab nthab ntawm kwv yees li 110℃(230℃F) txwv nws daim ntawv thov hauv cov txheej txheem kub da dej lossis siab -watt- ntom ntom rau cov cua sov. Hauv qab qhov pib, PTFE ua tau zoo heev; saum toj no, cov khoom pib soften, creep, thiab poob txhua yam kev ncaj ncees. Tsis tas li ntawd, cov ntshiab PTFE nthuav tawm cov thermal conductivity tsawg thiab tsis zoo rau cov kua dej abrasive, yam uas txwv cov cua sov tsim thiab ua kom ntev.
Taw qhia Fluoropolymer Blends: PFA-PTFE thiab Tshaj
Ib qho kev cog lus cog lus muaj kev sib xyaw PTFE nrog rau lwm cov perfluorinated polymers. PFA (perfluoroalkoxy) yog ib qho tshuaj txheeb ze ze uas tswj xyuas qhov kub thiab txias ntawm 260℃(500℃F) thaum muab cov inertness zoo sib xws rau yuav luag txhua yam tshuaj. Thaum cov khoom me me ntawm PFA tau muab sib xyaw rau hauv PTFE matrix, cov alloy uas ua rau pom kev txhim kho weldability, txo qhov porosity, thiab qhov muag muag ntau dua piv rau cov ntshiab PTFE. Qhov nofluoropolymer sib tov PTFE rhaub kev txhim khotso cai rau cua sov sheaths thiab fittings kom tiv taus qhov kub thiab txias spikes uas yuav deform tus qauv PTFE.
Lwm cov fluoropolymer modifiers muaj xws li FEP (fluorinated ethylene propylene) thiab MFA (ib terpolymer zoo ib yam li PFA). Txhua qhov sib tov kho cov khoom tshwj xeeb- ntws thaum lub sij hawm molding, adhesion rau hlau cores, los yog tsis kam mus permeation los ntawm aggressive gases - yam tsis muaj kev cuam tshuam qhov tseem ceeb corrosion kuj.
Cov txiaj ntsig zoo rau kev ua haujlwm ntawm cov cua sov
Blended fluoropolymer sheaths pab kom ob qho kev nce qib tseem ceeb. Ua ntej, lawv tso cai rau PTFE- raws li cov cua sov ua haujlwm ntawm cov watt ntau dua, txhais tau tias cov cua sov ntau tuaj yeem hloov mus los ntawm tib qhov chaw uas tsis muaj cua sov hauv cheeb tsam. Thib ob, lawv txhim kho kev tiv thaiv thermal cycling- rov ua cua sov thiab cua txias uas ua rau cov ntshiab PTFE tsim micro- tawg thiab delaminate los ntawm cov hlau cua sov. Hauv kev thov cov ntawv thov xws li semiconductor ntub etching lossis siab -purity kws tshuaj reactors, cov kev txhim kho no txhais ua lub neej ntev dua thiab txo qis qis.
PTFE Composites Reinforced: Fillers rau lub zog thiab kev coj ua
Tshaj li polymer-polymer blends, ntxiv inorganic fillers rau PTFE tsim cov khoom siv ntxiv nrog cov khoom sib txawv. Common fillers muaj xws li iav fiber, carbon hmoov, graphite, thiab bronze. Txhua qhov muab tub lim qhia cov kev txhim kho tshwj xeeb:
iav fiber ntau (15-25% ntawm qhov hnyav):Ua kom muaj zog txhua yam, hnav tsis kam, thiab creep kuj. Txo thermal expansion.
Carbon lossis graphite (5-15%):Txhim kho thermal conductivity, tso cua sov kom hloov tau zoo dua los ntawm cov cua sov sab hauv mus rau cov txheej txheem dej. Kuj txo cov nqi static buildup.
Bronze (40-60%):Siv feem ntau rau kev thauj khoom-cov kabmob cov khoom siv kho tshuab, feem ntau tsis yog rau cov khoom siv hluav taws xob vim txo cov tshuaj lom neeg.
Rau cov khoom siv cua sov, graphite- puv PTFE yog qhov tseem ceeb tshaj qhov kev txhawb nqa. Cov thermal conductivity siab dua txhais tau tias lub tshuab cua sov saum npoo ua kom txias rau tib lub zog tawm tswv yim, txo qhov kev pheej hmoo ntawm polymer degradation. Txawm li cas los xij, ntxiv ib qho muab tub lim qhia txog kev lag luam -tawm: tshuaj tiv thaiv tsis muaj tseeb. Filled PTFE feem ntau yog siv rau cov khoom siv kho tshuab xws li mounting brackets, compression seals, lossis cov qauv kev txhawb nqa uas tsis ncaj qha rau hauv corrosive media. Nws siv nyob rau hauv immersion rhaub sheaths tseem niche, tseg rau daim ntaub ntawv qhov twg cov kua yuav zam tau ib tug kab los yog carbon kab mob.
Tswv yim cuam tshuam: nthuav lub hnab ntawv ua haujlwm
Tam sim no nws muaj peev xwm siv tau PTFE-style heaters nyob rau hauv cov txheej txheem yav tas los yuav tsum tau txawv hlau cua sov xws li titanium, tantalum, los yog zirconium. Piv txwv li, PFA-PTFE sib xyaw sheath tuaj yeem tiv taus kev ua haujlwm tsis tu ncua ntawm 150℃txog 180℃hauv cov kua qaub sib xyaw ua ke uas cov hlau tsis muaj steel yuav ua tsis tiav hauv cov xuab moos. Ib yam li ntawd, ib qho graphite- txhawb nqa PTFE lub taub rhaub dej tuaj yeem tso cov watt ntau dua yam tsis muaj qhov kub thiab txias, ua rau nws tsim nyog rau cua sov cov kua dej los yog siab - ntws tshuab.
Lwm qhov ua tau zoo yog txhim kho weldability. Ntshiab PTFE yog tsis yooj yim rau weld; pob qij txha feem ntau yog ua los ntawm cov xov los yog clamped fittings. PFA-nplua nuj blends tuaj yeem ua cua sov-welded siv cov khoom siv fluoropolymer vuam txheej txheem, tso cai rau kev tsim cov txheej txheem, seamless heater geometries uas txhim khu kev qha thiab xau- tiv taus.
Kev txiav txim siab thiab kev txwv
Cov kws tsim khoom yuav tsum lees paub tias kev xaiv cov khoom tseem tshuav ntawm tus nqi, kev ua tau zoo, thiab kev sib raug zoo ntawm cov tshuaj. PFA tseem kim dua PTFE-feem ntau ob mus rau peb npaug ntawm tus nqi raw khoom. Blends uas suav nrog PFA lossis FEP hais kom tus nqi sib xws. PTFE composites muaj feem ntau tsis tshua kim tshaj PFA tab sis qhia txog kev pheej hmoo kis kab mob. Rau ultra- ntshiab lossis semiconductor- cov ntawv thov qib, txawm tias cov kab lim dej lim dej tuaj yeem ua tsis tau.
Tsis tas li ntawd, cov txheej txheem tsim khoom rau cov khoom sib txawv ntawm PTFE ntshiab. Compression molding thiab sintering tsis yuav tsum tau kho rau txhua formulation. Tsis yog txhua tus neeg tsim khoom tsim muaj kev paub dhau los nrog PFA-PTFE cov khoom sib xyaw lossis cov khoom sib txuas ntxiv, uas tuaj yeem txwv cov kev xaiv.
Cov lus qhia yav tom ntej hauv Fluoropolymer Heater Materials
Kev tshawb fawb tsis tu ncua yog tshawb nrhiav nanofillers -xws li cov pa roj carbon nanotubes lossis boron nitride particles - los txhim kho cov thermal conductivity yam tsis muaj kev cuam tshuam cov tshuaj tiv thaiv. Lwm thaj chaw ntawm txoj kev loj hlob yog multilayer co-extrusion, qhov twg nyias, ntshiab PTFE txheej txheej tiv thaiv ib tug muaj zog los yog ntau conductive puab txheej. Cov kev nce qib no tau cog lus rau decouple deg inertness los ntawm cov khoom siv hluav taws xob ntau, muab qhov zoo tshaj plaws ntawm ob lub ntiaj teb.
Xaus
Cov ntaub ntawv fluoropolymer Advanced tau maj mam nthuav dav cov kev txwv kev ua haujlwm ntawm corrosion- cov cua sov tiv taus. PFA-PTFE blends muab qhov ntsuas kub siab dua thiab zoo dua weldability, thaum ntxiv PTFE composites muaj zog txhua yam thiab thermal conductivity. Txhua qhov kev xaiv cov khoom siv sib txawv ntawm kev lag luam tawm - tawm ntawm tus nqi, tshuaj lom neeg sib raug zoo, thiab kev tsim khoom nyuaj. Raws li cov txheej txheem kub nce thiab tshuaj lom neeg ib puag ncig ua nruj, qhov muaj ntawm cov tom ntej no - tiam fluoropolymer muab cov engineers dav dua palette rau tsim txhim khu kev qha, ntev - nyob PTFE cua sov daws. Kev xaiv cov khoom, txawm li cas los xij, tseem tshuav qhov sib npaug ntawm tus nqi, kev ua haujlwm, thiab kev sib raug zoo ntawm cov tshuaj lom neeg tshwj xeeb- tsis muaj ib qho kev sib xyaw ua ke zoo rau txhua daim ntawv thov.
