Qhov tseeb ciam teb nyob rau hauv sealing engineering yog lub hauv paus ntawm ciam teb ntawm sealing mechanisms. Elastomeric seals feem ntau vam khom elastic rov qab tom qab compression los tsim qhov pib sealing quab yuam, thiab qhov nruab nrab siab ntxiv amplifies kev sib cuag. Thaum compression txheej dhau lawm thiab cov khoom poob nws elastic nco, sealing tsis ua hauj lwm tshwm sim. Nyob rau hauv sib piv, engineering plastics xws li PTFE, UHMWPE, thiab PEEK muaj inherently tsis muaj zog elastic rov qab, thiab PTFE tshwj xeeb qhia tau hais tias txias txaus los yog creep. Yog li ntawd, cov ntaub ntawv no tsis ua haujlwm los ntawm "caij nplooj ntoos hlav rov qab zoo li roj hmab," tab sis tsuas yog tso siab rau cov qauv tsim qauv, kev ua ntej, kev ua kom siab, qhov dej, lossis O- lub nplhaib energization kom tswj tau qhov kev sib khi. Qhov no txhais tau hais tias tus ciam teb tseem ceeb ntawm cov ntaub ntawv tsis yog -elastomer sealing cov ntaub ntawv: cov lus nug tseem ceeb tsis yog cov khoom muaj zog npaum li cas, tab sis nws lub luag haujlwm yog dab tsi hauv lub cev -txawm nws muab kev them nyiaj elastic, lossis seb nws puas ua haujlwm xws li kev sib txhuam qis, hnav tsis kam, tshuaj tiv thaiv, extrusion resistance, lossis load- bearing. Cov qub yog cov elastomers, thaum yav tas los piav qhia vim li cas cov yas yas nkag mus rau kev sib khi.
1. PTFE
PTFE yuav tsum tsis txhob to taub yooj yim raws li ib tug "siab-} yas kawg," tab sis yog ib yam khoom uas ib txhij thawb peb qhov tseem ceeb ciam teb: tshuaj tiv thaiv, kub tsis kam, thiab tsis muaj kev sib txhuam. Raws li AGC cov ntaub ntawv, nws qhov kev pabcuam kub ib txwm yog kwv yees li ntawm -180℃txog +260 degree, thiab nws yog chemically inert rau yuav luag tag nrho cov xov xwm. Cov ntaub ntawv Parker qhia tau hais tias PTFE nthuav tawm qhov kev sib txhuam qhuav zawv zawg tiv thaiv cov hlau ntawm li 0.10, uas yog qis dua UHMWPE ntawm kwv yees li 0.25 thiab nkauj xwb PEEK ntawm kwv yees li 0.35. Qhov no txhais tau hais tias PTFE hauv paus txuas ntxiv qhov kev ua haujlwm siab tshaj ntawm elastomer -raws li cov ntsaws ruaj ruaj nyob rau hauv siab - kub, muaj zog corrosive, thiab tsis tshua muaj kev sib txhuam dynamic ib puag ncig.
Txawm li cas los xij, nws cov kev txwv tseem ceeb sib npaug. Parker sau tseg tias nkauj xwb PTFE qhia tau hais tias nkag mus rau hauv qhov nruam load txawm nyob rau hauv chav tsev kub thiab yuav luag tsis muaj elastic rov qab. Txawm hais tias nws qhov kev sib txhuam tsawg heev, nws cov kev hnav tsis zoo kuj tsis zoo. Qhov no ua rau nws tsis tsim nyog los kho PTFE raws li qhov siab - roj hmab kub lossis ua ib qho kev hloov tsis zoo rau elastomeric O-rings. Ib qho yuam kev engineering feem ntau yog kom tsis meej pem nrog kev sib txhuam qis nrog kev txhim khu kev qha elastic sealing muaj peev xwm. Hauv kev siv tswv yim, PTFE yog li tsis tshua siv ib leeg. Ib txoj hauv kev yog kev hloov kho siv cov khoom siv xws li iav fiber ntau, carbon fiber, graphite, lossis tooj liab los txhim kho creep resistance, hnav tsis kam, compressive zog, thiab tiv thaiv -extrusion muaj peev xwm. Lwm txoj hauv kev yog kev siv lub zog sib khi cov qauv xws li lub caij nplooj ntoos hlav- cov ntsaws ruaj ruaj lossis elastomer- tsim kom muaj zog, qhov twg cov springs lossis O-rings them nyiaj rau qis- kev sib cuag thiab ntev - lub sij hawm deformation.
Los ntawm kev xav engineering, PTFE yuav tsum raug suav hais tias yog cov khoom siv uas rhuav tshem cov ciam teb ntawm kev sib raug zoo hauv xov xwm, kub, thiab kev sib txhuam, tsis yog ib qho uas muab geometric lossis elastic them nyiaj. Nws yog qhov zoo tshaj plaws rau cov xwm txheej uas muaj qhov kub thiab txias, muaj zog tshuaj lom neeg raug, lossis qis - kev sib txhuam dynamic motion, thaum nws tsis zoo tagnrho thaum qhov tseem ceeb yuav tsum tau loj deformation ua raws los yog ntev - lub sij hawm elastic rov qab.
2. UHMWPE
UHMWPE nthuav qhia ib thaj tsam ntawm cov khoom sib txawv kiag li piv rau PTFE. Noj Ensinger PE1000 ua piv txwv, UHMWPE yog tus cwj pwm los ntawm kev cuam tshuam hnyav heev, hnav zoo heev thiab ua haujlwm tsis zoo, muaj zog zawv zawg coj tus cwj pwm, thiab kev ua haujlwm kub siab tshaj -. Cov khoom muaj xws li tensile modulus txog 700 MPa, lub zog tawm ntawm kwv yees li 19 MPa, thiab qhov kev pabcuam kub ntawm ib ncig ntawm -260℃rau +80℃.
Nws cov khoom xwm tsis yog qhov siab -kub- cov yas resistant, tab sis yog ntawm hnav- tiv taus thiab cuam tshuam - resistant engineering polymer. Raws li Parker, UHMWPE yog ib qho nyuaj tshaj plaws thiab feem ntau hnav- cov ntaub ntawv tiv taus, tab sis nws muaj qhov kub thiab txias thiab tshuaj tiv thaiv ntau dua piv rau PTFE thiab yog qhov tsim nyog rau reciprocating los yog qeeb heev zawv zawg daim ntaub ntawv, nrog kev sib txhuam coefficient ntau dua li PTFE. Trelleborg txoj haujlwm UHMWPE feem ntau yog cov khoom siv rau kev taw qhia ntiv nplhaib thiab hnav cov nplhaib hauv lub tog raj kheej hydraulic, qhov uas nws nqus sab loads, coj pistons lossis rods, thiab tiv thaiv hlau -rau-hlau sib cuag.
Hauv lwm lo lus, UHMWPE yog qhov ua kom zoo rau kev hnav tsis kam, kev taw qhia, qis - kub toughness, thiab qeeb zawv zawg zog, es tsis yog rau kev sib tw nrog PTFE nyob rau hauv siab - kub los yog tshuaj lom neeg nruj heev. Ib qho kev nkag siab tsis zoo yog kho UHMWPE raws li tus nqi qis - tus nqi hloov pauv rau PTFE, thaum qhov tseeb lawv lub luag haujlwm sib txawv: PTFE yog tsim los rau cov tshuaj lom neeg tsis kam, kub kub, thiab ultra- tsis tshua muaj kev sib txhuam, qhov UHMWPE yog tsim los rau hnav tsis kam, cuam tshuam, thiab qis -.temperature durability
3. PEB
PEEK tuav lub luag haujlwm ntau dua hauv cov tshuab sealing. Raws li Victrex cov ntaub ntawv, PEEK muaj siab - qhov kub thiab txias muaj peev xwm, dav tshuaj tsis kam, siab txhua yam muaj zog, zoo heev dimension stability, hydrolysis tsis kam, thiab hnav tsis kam. Piv txwv li, tus qauv 450G qib nthuav tawm qhov tensile modulus ntawm kwv yees li 4.0 GPa, lub zog tensile ntawm txog 98 MPa, thiab kev pabcuam txuas ntxiv mus txog 260 degree.
Qhov no qhia tau meej meej tias PEEK tsis yog ib qho mos-cov khoom sib txuas tab sis yog siab -modulus structural polymer. Nyob rau hauv daim ntawv thov sealing, nws yog tsuas yog siv rau rov qab - nce rings, anti-extrusion Cheebtsam, qhia cov ntsiab lus, thiab load- bearing yam ntxwv qhov chaw. Trelleborg faib PEEK raws li qhov siab -modulus engineering yas siv rau hauv kev taw qhia thiab hnav daim ntaub ntawv, thiab rov qab- cov nplhaib ua los ntawm PEEK yog tsim tshwj xeeb los tiv thaiv extrusion ntawm O-rings lossis X-rings nyob rau hauv siab.
Tus nqi ntawm PEEK nyob rau hauv kev nthuav dav ntawm thaj tsam ntawm kev ua haujlwm siab, kev tswj qhov sib txawv, kev thauj khoom -cov kabmob muaj peev xwm, thiab qhov ruaj khov. Txawm li cas los xij, PEEK tsis yog cov khoom siv sib khi thoob ntiaj teb. Nws tsis haum rau cov xwm txheej uas yuav tsum tau ua raws li qhov loj ntawm deformation los yog kam rau ua kom haum, thiab nws cov kev sib txhuam coefficient siab dua li ntawm PTFE. Yog li ntawd, PEEK yuav tsum to taub feem ntau yog cov qauv thiab tiv thaiv - cov ntaub ntawv extrusion es tsis yog lub hauv paus sealing.
4. PU (TPU)
Polyurethane, feem ntau hu ua TPU hauv kev sib khi daim ntaub ntawv, yog dav suav hais tias yog cov khoom siv hauv hydraulic dynamic sealing. Parker piav txog TPU raws li qhov ntev - tau tsim cov qauv ntsuas hauv cov kua hluav taws xob vim nws qhov kev hnav zoo heev, thermal stability, hydrolysis tsis kam, compression teeb ua haujlwm, thiab elastic rov qab. Covestro kuj tseem hais txog nws qhov kev ua haujlwm siab ua haujlwm, kev hloov pauv dav dav, siab elasticity, thiab ua haujlwm zoo rau cov roj thiab qee cov kuab tshuaj.
Qhov no tso TPU nyob rau hauv ib qho chaw nruab nrab ntawm elastomers thiab engineering plastics. Nws khaws elasticity thaum txhim kho kev hnav lub neej thiab kev ua haujlwm zoo, ua rau nws muaj txiaj ntsig tshwj xeeb hauv siab -siab dynamic hydraulic applications. Txawm li cas los xij, nws qhov tseeb lub zog yog tshwj xeeb hauv kev sib khi hydraulic dynamic es tsis yog universal chemical resistance lossis zoo li qub sealing tej yam kev mob.
Ib qho kev nkag siab yuam kev tseem ceeb yog kho TPU ua ib qho khoom siv sib xws, thaum qhov tseeb nws cov tshuaj tiv thaiv yog nyob ntawm kev tsim, hardness, kub, concentration, thiab lub sij hawm raug. Muaj zog acids thiab alkalis tuaj yeem degrade TPU, muaj ntxhiab hydrocarbons ua rau o, ketones thiab esters ua rau o tseem ceeb, thiab cov kuab tshuaj xws li DMF, DMSO, NMP, thiab THF tuaj yeem yaj nws. Qhov kub thiab txias kuj sib txawv los ntawm kev tsim, nrog MDI -raws li tshuab feem ntau nyob ib ncig ntawm 100℃thiab PPDI -raws li cov tshuab ncav cuag li 135℃. Yog li ntawd, PU tsis yog txhais los ntawm ib tus ciam ciam nkaus xwb tab sis los ntawm cov txheej txheem - nyob ntawm tus ciam teb tsim.
5. Engineering ciam teb ntawm elastomers thiab engineering plastics
Thaum engineering plastics thiab elastomers suav nrog ua ke, cov ciam teb tseem ceeb tuaj yeem nkag siab ntau txoj hauv kev. Elastomers feem ntau yog lub luag haujlwm rau kev tsim cov sealing quab yuam los ntawm elastic rov qab, thaum engineering plastics xws li PTFE, UHMWPE, thiab PEEK tsis cia siab rau elastic deformation tab sis es tsis txhob ncua kev ua tau zoo ciam teb los ntawm kev sib txhuam qis, hnav tsis kam, tshuaj tiv thaiv, extrusion tsis kam, thiab seem stability.
Lawv lub luag haujlwm ua haujlwm tau sib txawv kom meej meej: PTFE feem ntau hais txog tshuaj lom neeg, qhov kub thiab txias, thiab kev txwv kev sib txhuam; UHMWPE tsom rau kev hnav tsis kam, kev taw qhia, qis- qhov kub thiab txias, thiab qeeb zawv zawg; PEEK yog siv rau kev thauj khoom-cov kabmob, tiv thaiv-extrusion, thiab siab-siab cov qauv kev ruaj ntseg; thiab PU yog optimized rau hnav lub neej nyob rau hauv dynamic hydraulic tej yam kev mob. Hauv kev xyaum, cov kev daws teeb meem zoo tshaj plaws feem ntau tsis yog hloov pauv tab sis cov tshuab hybrid. Piv txwv li, O- lub nplhaib tuaj yeem muab kev sib txuas ua ntej thiab pib lub zog, thaum lub tes tsho PTFE txo kev sib txhuam thiab txhim kho cov tshuaj tiv thaiv, thiab PEEK lossis puv PTFE rov qab- lub nplhaib tuaj yeem tiv thaiv extrusion nyob rau hauv siab.
Qhov feem ntau yuam kev engineering yog sib piv cov ntaub ntawv nyob rau hauv txawv sealing mechanisms. PTFE tsis yog siab-kawg roj hmab, PEEK tsis yog yas yas, UHMWPE tsis yog pheej yig version ntawm PTFE, thiab PU tsis yog ib qho nyuaj version ntawm NBR. Thaum cov hom tsis ua hauj lwm tseem ceeb raug txheeb xyuas kom raug, cov khoom ciam teb yuav pom tseeb.
