Kev kub siab npaum li cas hloov cov tshuaj tiv thaiv ntawm PTFE cua sov phaj?

Nyob rau hauv ib puag ncig ua tshuaj, ib qho txawv txawv ntawm kev ua tsis tiav tuaj yeem tshwm sim. Lub PTFE cua sov phaj ua haujlwm zoo rau xyoo ntawm qhov kub nruab nrab thiab tuaj yeem tswj tau qee yam tshuaj yam tsis muaj kev qhia txog kev hnav thiab tsim kua muag. Raws li kev tsim khoom xav tau nce, qhov kev ua haujlwm kub tau hloov kho kom nrawm dua, thiab nyob rau hauv ob peb lub hlis, tib lub phaj qhia pom cov tsos mob ntawm dulling, microcracking, lossis poob ntawm cov neeg kho tshuab kev ncaj ncees. Cov tshuaj pleev ib ce tseem zoo li qub. Qhov kub tau nce mus xwb.

Qhov xwm txheej no qhia txog txoj cai yooj yim hauv cov khoom siv engineering: tshuaj tiv thaiv kev hloov pauv nrog kub. Ntawm 150 degree, qhov nruab nrab zoo li muaj kev nyab xeeb ntawm 50℃tuaj yeem ua rau muaj kev phom sij ntau dua. Thaum siv PTFE cua sov daim hlau ze rau lawv cov kev txwv kub siab, nws tseem ceeb heev kom paub tias qhov kev sib raug zoo no ua haujlwm li cas.

Lub Arrhenius kev sib raug zoo thiab ua kom muaj kev cuam tshuam
Kev sib raug zoo ntawm Arrhenius piav qhia txog qhov kub thiab txias thiab tshuaj lom neeg muaj feem cuam tshuam li cas. Txhawm rau muab nws yooj yim, tus nqi ntawm cov tshuaj tiv thaiv tshuaj mus nce ntau thaum qhov kub nce mus. Ib txoj cai lij choj ntawm tus ntiv tes xoo hais tias cov tshuaj tiv thaiv kwv yees li ob npaug rau txhua 10℃nce hauv qhov kub thiab txias.

Tus cwj pwm exponential no muaj qhov cuam tshuam tseem ceeb heev. Ntawm 150 degree, cov tshuaj tiv thaiv uas txav mus qeeb qeeb ntawm 50℃uas nws yuav siv sij hawm ntau xyoo los ua rau muaj kev phom sij loj tuaj yeem ua kom nrawm dua. Tib qho kev sib cuam tshuam molecular tshwm sim, tab sis lawv tshwm sim sai dua.

Rau PTFE cua sov daim hlau, qhov no txhais tau hais tias cov tshuaj sib raug zoo thiab qhov kub thiab txias - nyob ntawm seb yuav tsum tau kuaj xyuas tib lub sijhawm. PTFE yog qhov zoo-paub tias nws yog inert heev, txawm hais tias nws tseem tuaj yeem tawm tsam sai dua thaum qhov kub thiab txias.

Siab -Tsub Degradation Mechanisms
PTFE muaj kev sib txuas zoo ntawm cov pa roj carbon thiab fluorine uas ua rau nws tiv taus ntau cov kua qaub, cov hauv paus, thiab cov kuab tshuaj. Tab sis raws li qhov kub thiab txias tau los ze zog rau cov khoom siv sab saud, uas feem ntau yog nruab nrab ntawm 200℃thiab 260℃nyob ntawm tus qauv tsim, cov tshuaj lom neeg ruaj khov margins tau tsawg dua.

Oxidative deterioration feem ntau yuav tshwm sim hauv qhov chaw oxidizing muaj zog thaum kub siab. PTFE feem ntau xav tias yuav sib haum nrog cov concentrated sulfuric acid ntawm chav tsev kub, piv txwv li. Qhov chaw oxidation qeeb tuaj yeem tshwm sim ntawm qhov kub thiab txias ze li 200 degree, tshwj xeeb tshaj yog nyob ze ntawm cov khoom siv siab tshaj plaws. Thaum xub thawj, qhov kev puas tsuaj yuav me me, xws li roughening lossis discoloration ntawm qhov chaw, tab sis nws tuaj yeem tshwm sim nrog lub sijhawm.

Tib lub tswv yim muaj tseeb rau ntau yam oxidising agents, halogenated compounds ntawm qhov kub thiab txias, los yog reactive gases ntawm lub siab. Kev sib xyaw ua ke ntawm cov cua sov thiab tshuaj lom neeg ua rau nws muaj feem ntau tias cov ntawv cog lus yuav tawg lossis qhov chaw yuav raug tawm tsam.

Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias kev kub ntxhov kuj tseem tuaj yeem ua lub luag haujlwm. Thaum qhov kub nce mus, cov khoom siv zoo xws li lub zog tensile thiab creep kuj poob. Thaum cov tshuaj ntxiv rau txhua yam uas twb tsis muaj zog mechanically, qhov kev pheej hmoo ntawm kev puas tsuaj nce ntxiv.

Yuav ua li cas kom nkag siab qhov kub thiab txias -Cov ntaub ntawv sib raug zoo
Chemical compatibility tables feem ntau qhia ntau qhov kev pab kub siab tshaj plaws rau tib yam tshuaj. Cov khoom siv tuaj yeem sau npe tias "txaus siab" txog 100 degree, txawm hais tias tej zaum yuav muaj cov ntaub ntawv txwv lossis cov ntaub ntawv muaj nyob rau ntawm qhov kub siab dua. Cov kev sib txawv no zoo li cov cim ceeb toom ntau dua li cov ntawv me me.

Hauv kev xyaum, ntau daim ntawv qhia kev sib raug zoo muab cov qhab nia zoo ntawm qhov kub nruab nrab tab sis tsis muaj kev ntseeg siab ntawm qhov kub siab dua. Yog tias tsis muaj cov ntaub ntawv kub ntau tshaj ib theem tshwj xeeb lossis yog tias nws tau teev raws li qhov txwv, koj yuav tsum tsis txhob xav tias qhov kub siab tshaj - ua tau zoo.

Thaum PTFE raug rau cov tshuaj hnyav, nws qhov ntsuas kub siab tshaj plaws feem ntau qis dua li cov polymer cov kev txwv dav dav. Qhov no qhia tau hais tias cov tshuaj lom neeg ua haujlwm thiab qhov kub thiab txias li cas - nyob ntawm qhov ua haujlwm ua haujlwm ua ke, tsis yog kev txwv thermal xwb.

Cov kws kho tsheb yuav tsum ntsuas kev sib raug zoo ntawm qhov ntsuas kub ua haujlwm, tsis yog nyob rau hauv ib puag ncig lossis keeb kwm chaw.

Thermal Margin thiab Derating Guidelines
Thaum cov xov xwm tawm tsam, nws yog qhov zoo tshaj los ua raws li kev saib xyuas kev noj qab haus huv. Khaws qhov sib txawv ntawm qhov sib txawv ntawm qhov kub thiab txias ntawm cov khoom siv ntsuas qhov siab tshaj plaws pab kom nws kav ntev dua.

Thaum muaj cov oxidisers uas muaj zog los yog cov kua qaub muaj zog, nws yog ib txwm muaj kev nyab xeeb ua kom qhov kub thiab txias hauv qab qhov ntsuas kub siab tshaj plaws los ntawm 20 txog 30 degree. Cov npoo no ua rau thaj tsam kub, kub hloov pauv, thiab tsis meej pem hauv kev ntsuas.

Derating yog qhov tseem ceeb tshwj xeeb tshaj yog thaum qhov kub ntawm cov txheej txheem tau nce me ntsis los ntawm kev txhawb nqa kev tsim khoom. Kev sib txuas ntawm Arrhenius hais tias txawm tias qhov kev hloov pauv me me ntawm qhov kub thiab txias, xws li 20℃lossis 30 degree, tuaj yeem ua rau muaj tshuaj lom neeg ntau.

Ua ntej hloov qhov kub thiab txias, kev txheeb xyuas kev sib raug zoo yuav tsum koom nrog saib cov ntaub ntawv tsim khoom, tshuaj xyuas cov lus hloov kho tshiab, thiab, yog tias cov txheej txheem tseem ceeb, xav txog kev kuaj qhov chaw kuaj.

Nrhiav cov cim qhia ntxov ntawm kev degradation
Koj yuav tsum tau ceev faj thaum ua haujlwm nrog cov tshuaj ntawm qhov kub thiab txias. Qee cov cim qhia ntxov tias qhov chaw tawg yog qhov poob ntawm qhov ci, kev hloov me me ntawm cov xim, tawv tawv ntawm qhov chaw, lossis microcracking. Cov no yuav tsis cuam tshuam rau kev ua haujlwm tam sim ntawd, tab sis lawv txhais tau tias cov kev txwv ntawm kev tiv thaiv uas nyob ntawm qhov kub thiab txias tau ze.

Thaum ua hauj lwm ze ntawm qhov kub thiab txias, cov sij hawm soj ntsuam xyuas yuav tsum tau hloov. Kev tshuaj xyuas qhov muag, ntsuas qhov ntev, thiab tshuaj xyuas cov neeg kho tshuab kev ncaj ncees tuaj yeem pab nrhiav teeb meem ua ntej lawv loj tuaj.

Hauv cov txheej txheem uas ntsuas qhov ntsuas qhov ntsuas kub, txawm tias cov cim me me ntawm kev degradation yuav tsum ua rau koj rov xav txog koj qhov thermal margin thiab derating lub tswv yim.

Muab tso ua ke thermal thiab tshuaj yam tseem ceeb
Thaum siv PTFE cua sov daim hlau, koj tsis tuaj yeem cais qhov kub thiab txias. Raws li qhov kub nce siab, ib puag ncig tshuaj lom neeg uas muaj kev nyab xeeb ntawm qhov kub nruab nrab tuaj yeem ua rau muaj kev kub ntxhov. Txoj kev sib raug zoo ntawm Arrhenius qhia tau hais tias yog vim li cas cov tshuaj tiv thaiv kom nrawm dua exponentially es tsis txhob linearly. Qhov no txhais tau tias ntau xyoo ntawm kev sib cuag qeeb tuaj yeem ua rau lub hlis ntawm kev puas tsuaj pom.

Txhawm rau ua qhov kev ntsuam xyuas kom raug, koj yuav tsum tau saib qhov kub thiab txias - cov ntaub ntawv tiv thaiv nyob ntawm, ua raws li cov cai ceev faj, thiab muaj cov thermal tsis zoo thaum cov tshuaj hnyav nyob ib puag ncig. Nws yog ib lub tswv yim zoo los xyuas cov cua kub txhua zaus rau cov cim qhia ntxov ntawm oxidative degradation los yog qhov chaw hloov pauv yog tias lub kaw lus khiav ze rau nws cov khoom txwv. Hloov cov khoom raws sij hawm raws li qhov koj pom ua rau cov txheej txheem txhim khu kev qha thiab nres qhov tsis tau npaj txhij txog hauv qhov chaw muaj tshuaj lom neeg hnyav nrog qhov kub thiab txias.