Nkag siab txog Kev Ciam Teb ntawm Tsis yog -Elastomer Sealing Materials

Qhov kev txwv tiag tiag hauv kev sib khi engineering yog qhov tseeb qhov txwv ntawm cov txheej txheem sealing. Elastomeric seals feem ntau nyob ntawm qhov elastic rov qab los ntawm compression rau thawj zaug sealing quab yuam, nrog rau kev sib cuag kev ntxhov siab nce los ntawm nruab nrab siab. Sealing tsis ua hauj lwm tshwm sim thaum lub compression teeb tau loj heev thiab cov khoom poob nws elastic nco. Ntawm qhov tod tes, engineering plastics xws li PTFE, UHMWPE thiab PEEK muaj cov khoom tsis zoo elastic rov qab, nrog PTFE tshwj xeeb nthuav tawm cov dej txias lossis nkag. Cov ntaub ntawv no tsis khaws lawv cov kev sib khi los ntawm "caij nplooj ntoos hlav rov qab zoo li roj hmab," tab sis los ntawm kev tsim qauv geometric, preload, siab ua kom muaj zog, springs, lossis O-ring energization. Qhov no yog qhov kev txwv tseem ceeb ntawm cov khoom tsis yog-elastomer sealing cov ntaub ntawv: cov lus nug tseem ceeb tshaj plaws tsis yog cov khoom siv zog npaum li cas, tab sis nws ua haujlwm li cas hauv lub cev, txawm tias nws muab cov nyiaj elastic los yog seb nws siv rau lwm yam haujlwm xws li kev sib txhuam qis, hnav tsis kam, tshuaj tiv thaiv, extrusion tsis kam lossis load bearing. Lub qub yog cuam tshuam nrog elastomers thaum tom kawg muab cov laj thawj rau engineering plastics nkag mus rau hauv daim ntawv thov sealing.

1. PTFE PTFE tsis yog yuav tsum tau saib raws li tsuas yog "siab-cov yas kawg". Hloov chaw nws yog ib yam khoom uas txhawb nqa peb qhov tseem ceeb nyob rau tib lub sijhawm: tshuaj tiv thaiv, kub tsis kam, thiab txo kev sib txhuam. Raws li AGC cov ntaub ntawv, nws qhov kev pabcuam kub ntau yog li ntawm -180℃rau +260℃, thiab nws yog chemically inert rau xyaum ua txhua yam xov xwm. Parker kev tshawb fawb qhia tau hais tias PTFE muaj ib tug qhuav zawv zawg kev sib txhuam coefficient tiv thaiv hlau ntawm kwv yees li 0.10, ntau qis dua UHMWPE ntawm txog 0.25 thiab nkauj xwb PEEK ntawm txog 0.35. Qhov no txhais tau hais tias PTFE qhov tseem ceeb nce qhov siab tshaj plaws kev txwv ntawm elastomer{11}}raws li cov ntsaws ruaj ruaj nyob rau hauv qhov kub thiab txias, muaj zog corrosive thiab tsis tshua muaj kev sib txhuam dynamic.

Tab sis nws cov kev txwv tseem ceeb sib npaug. Raws li Parker, nkauj xwb PTFE muaj qhov nkag tau ntau heev ntawm chav tsev kub hauv qab kev ntxhov siab thiab qhov tseem ceeb tsis muaj elastic rebound. Nws hnav tsis kam yog qhov tsis zoo txawm tias nws muaj kev sib txhuam tsawg heev. Yog li ntawd, nws tsis siv tau los xav txog PTFE raws li qhov siab - roj hmab kub lossis ib qho nyuaj rau lwm qhov elastomeric O-rings. Ib qho yuam kev nyob rau hauv engineering yog los txhais lus tsis sib haum xeeb rau kev txhim khu kev qha elastic sealing peev xwm. Hauv kev xyaum, yog li ntawd, PTFE tsis tshua siv ib leeg. Ib txoj hauv kev yog hloov cov muab tub lim, ntxiv cov ntaub ntawv xws li iav fiber ntau, carbon fiber, graphite lossis bronze los txhim kho creep resistance, hnav tsis kam, compressive zog thiab tiv thaiv -extrusion peev xwm. Lwm qhov kev xaiv yog kev ua haujlwm ntawm lub zog sib khi cov qauv xws li lub caij nplooj ntoos hlav energized seals lossis elastomer energized designs qhov chaw springs lossis O-rings yog siv los them nyiaj rau kev sib cuag tsis tshua muaj siab thiab lub sij hawm ntev deformation.

Los ntawm engineering point of view PTFE tsis yog ib yam khoom rau geometrical los yog elastic kho tab sis ib yam khoom uas ua txhaum cov kev txwv ntawm kev sib raug zoo xov xwm, kub thiab kev sib txhuam. Nws yog qhov tsim nyog tshaj plaws rau kev kub siab, tshuaj lom neeg nruj lossis tsis tshua muaj kev sib txhuam dynamic motion dominated ib puag ncig. Nws tsis yog qhov zoo tshaj plaws thaum qhov tseem ceeb ntawm kev ua raws li kev ua raws li kev ua raws cai lossis kev rov ua kom elasticity ntev yog qhov tseem ceeb.

2. UHMWPE
PTFE muab tag nrho cov khoom sib txawv ciam teb piv rau UHMWPE. Piv txwv li, nrog Ensinger PE1000 UHMWPE muaj qhov cuam tshuam zoo heev, hnav zoo thiab ua haujlwm tsis zoo, kev coj tus cwj pwm zawv zawg siab thiab kev ua haujlwm kub tsis zoo. Cov yam ntxwv tsis zoo yog qhov tensile modulus ntawm ib ncig ntawm 700 MPa, lub zog tawm ntawm li 19 MPa thiab qhov kev pabcuam kub ntawm kwv yees li -260℃rau +80℃.

Nws cov khoom xwm tsis yog ntawm qhov kub siab tiv thaiv yas, tab sis yog qhov hnav thiab cuam tshuam resistant engineering polymer. Parker hais tias "UHMWPE yog ib qho nyuaj tshaj plaws, hnav- cov ntaub ntawv tiv taus," Parker hais. "Nws muaj kev txwv kub thiab tshuaj tiv thaiv ntau dua li PTFE, thiab yog qhov tsim nyog rau kev siv rov ua dua lossis qeeb qeeb heev. Cov kev sib txhuam coefficient siab dua PTFE." Trelleborg feem ntau ua lag luam UHMWPE rau kev siv cov nplhaib thiab hnav cov nplhaib hauv hydraulic thooj voos kheej kheej absorbing sab loads, coj pistons lossis rods thiab tiv thaiv hlau -rau-hlau sib cuag.

Hauv lwm lo lus, UHMWPE yog tsim los rau kev hnav tsis kam, kev taw qhia, toughness ntawm qhov kub thiab txias, thiab qeeb zawv zawg zog, tsis txhob sib tw nrog PTFE nyob rau hauv kub los yog tshuaj lom neeg mob hnyav. UHMWPE feem ntau yuam kev siv los ua tus nqi qis dua rau PTFE. Txawm li cas los xij, cov ntaub ntawv no muaj cov kev siv sib txawv. PTFE yog tsim los rau huab cua tsis kam, siab kub thiab tsis tshua muaj kev sib txhuam, qhov UHMWPE yog tsim los rau hnav tsis kam, cuam tshuam tsis kam thiab kub tsis kam.

3. PEEK PEEK yog ntau yam khoom siv hauv kev sib khi. Raws li cov ntaub ntawv Victrex, PEEK muaj qhov kub thiab txias, dav siv tshuaj tiv thaiv, muaj zog txhua yam, ruaj khov zoo, hydrolysis tsis kam thiab hnav tsis kam. Piv txwv li, qib 450G ib txwm muaj qhov tensile modulus ntawm ib ncig ntawm 4.0 GPa, lub zog tensile ntawm ib ncig ntawm 98 MPa thiab qhov kev pabcuam txuas ntxiv mus txog 260 degree.

Nws yog pov thawj tias PEEK tsis yog ib qho mos-cov khoom sib txuas tab sis yog siab -modulus structural polymer. Nws yog siv ntau hauv kev sib khi daim ntaub ntawv raws li lub nraub qaum- nce lub nplhaib, tiv thaiv- cov khoom siv extrusion, cov ntsiab lus qhia thiab thauj khoom- cov kabmob cov qauv. Trelleborg txhais PEEK raws li lub siab modulus engineering yas rau kev taw qhia thiab hnav daim ntaub ntawv. PEEK rov qab-ntiv nplhaib yog tsim los tiv thaiv O- nplhaib lossis X- nplhaib extrusion nyob rau hauv siab.

PEEK muaj nuj nqis rau nws lub zog los ua kom cov ciam teb ntawm kev ua haujlwm siab, kev tswj qhov sib txawv, kev thauj khoom muaj peev xwm thiab qhov ruaj khov. PEEK txawm li cas los xij tsis yog tag nrho cov hom phiaj sealing khoom. Nws tsis zoo rau cov ntawv thov uas xav tau ntau yam deformation ua raws lossis kam rau ua kom haum. Nws cov kev sib txhuam co-efficient yog siab dua PTFE. Yog li ntawd, PEEK yuav tsum raug suav hais tias feem ntau yog cov qauv / tiv thaiv - cov khoom siv extrusion thiab tsis yog cov khoom sib khi tseem ceeb.

4. PU (TPU)
Polyurethane (feem ntau hu ua TPU nyob rau hauv daim ntawv thov sealing) feem ntau suav hais tias yog cov khoom siv rau hydraulic dynamic sealing. TPU, Parker hais tias, yog lub sijhawm ntev - tau tsim cov qauv ntsuas hauv cov kua hluav taws xob rau nws qhov tshwj xeeb hnav tsis kam, thermal stability, hydrolysis tsis kam, compression teeb ua haujlwm thiab elastic rov qab. Covestro sau nws cov kev tiv thaiv muaj zog, kev hloov pauv dav dav, elasticity zoo thiab ua haujlwm zoo rau lubricants thiab qee cov kuab tshuaj.

Qhov no tso TPU rau hauv nruab nrab hauv nruab nrab ntawm elastomers thiab engineering plastics. Nws muaj qhov zoo elasticity thiab hnav lub neej ntev thiab kev ua haujlwm siab, ua rau nws zoo tagnrho rau kev siv hauv kev kub siab dynamic hydraulic ntawv. Tab sis nws lub zog tsis yog nyob rau hauv universal tshuaj tsis kam los yog zoo li qub sealing tej yam kev mob, tab sis nyob rau hauv dynamic hydraulic sealing.

Ib qho kev xav tsis zoo tshaj plaws yog TPU yog ib qho khoom siv. Tsis yog. Cov tshuaj tiv thaiv ntawm TPU yog nyob ntawm ntau hom, hardness, kub, concentration thiab ntev ntawm qhov raug. TPU yog qhov raug mob los ntawm muaj zog acids thiab alkalis; aromatic hydrocarbons ua o; ketones thiab esters ua rau muaj qhov o thaum cov kuab tshuaj xws li DMF, DMSO, NMP thiab THF tuaj yeem yaj nws. Qhov kub thiab txias kuj tseem yog tsim los ntawm MDI systems feem ntau txog 100℃thiab PPDI systems txog li 135 degree. Yog li ntawd, PU tsis yog txhais los ntawm ib tug tshwj xeeb ciam teb tab sis los ntawm formulation ciam teb tshwj xeeb rau lub system.

5. Engineering ciam teb ntawm elastomers thiab engineering yas
Qhov tseem ceeb txwv nyob rau hauv cov ntaub ntawv ntawm engineering plastics thiab elastomers coj ua ke tuaj yeem nkag siab ntau txoj hauv kev. Thaum elastomers feem ntau vam khom elastic rov qab los ua kom muaj kev sib khi, cov khoom siv yas xws li PTFE, UHMWPE, thiab PEEK tsis yog nyob ntawm elastic deformation tab sis hloov pauv qhov kev ua tau zoo ciam teb txog kev sib txhuam qis, hnav tsis kam, tshuaj tiv thaiv, extrusion tsis kam thiab qhov ruaj khov.

Lub luag haujlwm ua haujlwm ntawm PTFE yog qhov sib txawv ntawm peb qhov sib txawv: nws yog tsuas yog siv rau cov tshuaj lom neeg, kub thiab kev sib txhuam; UHMWPE yog siv rau kev hnav tsis kam, kev taw qhia, qis-kev ua haujlwm kub thiab qeeb qeeb; PEEK yog siv rau kev thauj khoom-cov kabmob, tiv thaiv-extrusion thiab siab-siab structural stability; PU yog siv rau hnav lub neej optimization nyob rau hauv dynamic hydraulic tej yam kev mob. Nyob rau hauv qhov tseeb, qhov zoo tshaj plaws sealing daws yog feem ntau hybrids, tsis hloov. Ib qho O- nplhaib tuaj yeem, piv txwv li, muab lub zog ua ntej thiab thawj zaug sib cuag, 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 yuam kev engineering feem ntau yog sib piv cov ntaub ntawv ntawm cov khoom sib txuas sib txawv. PTFE tsis yog cov roj hmab zoo nkauj, PEEK tsis yog yas yas, UHMWPE tsis yog ib qho pheej yig ntawm PTFE thiab PU tsis yog ib daim ntawv nyuaj ntawm NBR. Yog li yog tias koj paub tias hom kev ua tsis tiav yog dab tsi, koj tuaj yeem pom cov khoom siv ciam teb.