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

Lub ciam teb tiag tiag hauv sealing engineering yog nyob rau hauv cov ciam teb ntawm sealing mechanisms. Thawj qhov kev sib khi lub zog ntawm elastomeric seals feem ntau yog nyob ntawm qhov rov qab elasticity tom qab compression, thiab qhov nruab nrab siab yuav ua rau muaj kev sib tiv tauj ntxiv. Yog hais tias lub compression txheej dhau los ua zoo heev thiab cov khoom poob nws elastic nco, lub foob yuav poob. Hauv kev sib piv cov txheej txheem polymers xws li PTFE, UHMWPE thiab PEEK muaj qhov tsis tshua muaj elastic rov qab thiab PTFE tshwj xeeb qhia tau hais tias muaj qhov txias txias lossis nkag. Yog li cov ntaub ntawv no tsis ua hauj lwm los ntawm "snapping rov qab zoo li roj hmab" tab sis nyob rau hauv geometric tsim, preload, siab ua kom muaj zog, springs los yog O-ring energation rau sealing kev ua tau zoo. Qhov no txhais tau hais tias tus ciam teb tseem ceeb ntawm cov khoom tsis yog -elastomer sealing cov ntaub ntawv: cov lus nug tseem ceeb tsis yog cov khoom muaj zog npaum li cas, tab sis lub luag haujlwm nws ua haujlwm li cas hauv lub cev - seb nws puas muab kev them nyiaj elastic, lossis seb nws puas muab cov haujlwm xws li kev sib txhuam qis, hnav tsis kam, tshuaj tiv thaiv, extrusion tsis kam lossis load-cov kabmob. Lub qub yog nyob rau hauv elastomers thiab tom kawg yog vim li cas engineering plastics nrhiav lawv txoj kev mus rau sealing daim ntaub ntawv.

1. PTFE PTFE yuav tsum tsis txhob xav tias tsuas yog "siab-cov yas kawg", tab sis yog ib yam khoom uas ib txhij thawb peb thaj tsam tseem ceeb: tshuaj tiv thaiv, kub tsis kam, thiab tsis tshua muaj kev sib txhuam. AGC cov kev tshawb fawb qhia tau hais tias nws muaj qhov kev pabcuam kub ib txwm nyob ib puag ncig -180℃rau +260℃thiab yog cov tshuaj inert rau kev siv txhua yam xov xwm. Qhov qhuav zawv zawg txhuam coefficient ntawm PTFE ntawm cov hlau yog li 0.10 raws li cov ntaub ntawv Parker, uas yog qis dua UHMWPE (~ 0.25) thiab nkauj xwb PEEK (~ 0.35). Qhov no txhais tau hais tias PTFE ua tau zoo txav mus rau sab saum toj ntawm kev ua haujlwm ciam teb ntawm elastomeric{11}}raws li cov ntsaws ruaj ruaj nyob rau hauv qhov kub thiab txias, corrosive hnyav thiab tsis tshua muaj kev sib txhuam.

Tab sis nws cov shortcomings tsuas yog ib qho tseem ceeb. Parker hais tias nkauj xwb PTFE muaj ntau nkag ntawm chav tsev kub nrog ib tug tas li load thiab yeej tseem ceeb tsis muaj elastic rov qab. Kev sib txhuam tsawg heev tab sis hnav tsis kam yog qhov tsis zoo. Nws yog li no tsis raug rau kev txiav txim siab PTFE ua cov roj hmab kub kub los yog ib qho nyuaj sib npaug ntawm elastomeric O-rings. Ib qho kev ua yuam kev hauv engineering yog conflate txo kev sib txhuam nrog lub peev xwm los muab kev ruaj khov elastic foob. Yog li PTFE tsis tshua siv ib leeg hauv kev siv tiag tiag. Ib txoj hauv kev yog hloov cov muab tub lim los ntawm kev siv cov ntaub ntawv xws li iav fiber ntau, carbon fiber, graphite lossis bronze los txhim kho cov creep tsis kam, hnav tsis kam, compressive zog thiab anti-extrusion peev. Ib txoj hauv kev sib txawv yog kev ua haujlwm ntawm lub zog sib khi cov qauv xws li 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 qhov kev xav ntawm engineering, PTFE yuav tsum raug suav hais tias yog cov khoom siv uas ua txhaum txoj cai ntawm kev tshaj tawm kev sib raug zoo, qhov kub thiab kev sib txhuam, thiab tsis yog cov khoom siv uas muab cov nyiaj geometric lossis elastic. Nws yog qhov zoo tshaj plaws rau cov xwm txheej ntawm qhov kub thiab txias, aggressive chemical exposure los yog dynamic motion nrog me ntsis kev sib txhuam. Txawm li cas los xij, nws tsis yog qhov kev xaiv zoo tshaj plaws yog tias qhov kev xav tau loj yog kev ua raws li qhov loj me los yog lub sij hawm ntev elastic rov qab.

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

Nws tsis yog kub resistant yas nyob rau hauv nws cov khoom xwm tab sis ib tug hnav resistant thiab cuam tshuam resistant technical polymer. Parker hais tias "UHMWPE yog ib qho nyuaj tshaj plaws thiab feem ntau hnav cov ntaub ntawv tiv thaiv tab sis muaj qhov kub thiab tshuaj tiv thaiv ntau dua li PTFE thiab zoo dua rau cov ntaub ntawv rov qab los yog qeeb qeeb heev nrog cov coefficient ntawm kev sib txhuam ntau dua li PTFE. coj pistons los yog pas nrig thiab tshem tawm cov hlau - mus rau -hlau kov.

Hauv lwm lo lus, UHMWPE yog tsim los hnav resistant, kev taw qhia, tsis tshua muaj kub toughness thiab qeeb zawv zawg zog, tsis txhob sib tw nrog PTFE nyob rau hauv qhov kub thiab txias los yog chemically hnyav. UHMWPE feem ntau xav tias yog ib qho pheej yig hloov pauv rau PTFE, tab sis lawv lub luag haujlwm yog qhov tseeb sib txawv. PTFE yog tsim los rau huab cua tsis kam, kub kub thiab ultra- tsis tshua muaj kev sib txhuam, thaum UHMWPE yog tsim los rau hnav tsis kam, cuam tshuam tsis kam thiab kub kub toughness.

3. PEEK PEEK yog cov khoom siv ntau dua hauv cov tshuab sealing. Victrex cov ntaub ntawv hais tias PEEK muaj qhov kub thiab txias muaj peev xwm, muaj tshuaj lom neeg muaj zog, muaj zog txhua yam, ruaj khov zoo, hydrolysis tsis kam thiab hnav tsis kam. Piv txwv li, qhov raug 450G qib, muaj qhov tensile modulus ntawm kwv yees li 4.0 GPa, lub zog tensile ntawm txog 98 MPa thiab qhov kev pabcuam txuas ntxiv mus txog 260 degree.

PEEK yeej tsis yog ib qho muag muag -cov ntaub ntawv sib txuas, tab sis muaj cov qauv polymer siab. Nws feem ntau yog siv rau hauv daim ntawv thov sealing raws li rov qab- nce rings, tiv thaiv - cov khoom siv extrusion, cov ntsiab lus qhia thiab cov khoom siv thauj khoom. Rau kev taw qhia thiab hnav daim ntaub ntawv, Trelleborg faib PEEK raws li lub siab modulus engineering yas. PEEK rov qab-ntiv nplhaib yog tsim tshwj xeeb kom tsis txhob extrusion ntawm O-rings lossis X-rings nyob rau hauv siab.

Qhov kom zoo dua ntawm PEEK yog tias nws txuas ntxiv cov kev txwv ntawm kev ua haujlwm siab, kev tswj qhov sib txawv, kev thauj khoom nqa thiab qhov ntev stability. Tab sis PEEK tsis yog cov khoom siv sib khi thoob plaws ntiaj teb. Nws tsis yog qhov zoo tshaj plaws rau kev ua raws li qhov loj deformation los yog kam rau siab nqus daim ntawv thov thiab muaj cov coefficient ntawm kev sib txhuam ntau dua li PTFE. Nws yog li pom zoo kom xav txog PEEK raws li cov qauv thiab kev tiv thaiv - cov khoom siv extrusion tab sis tsis yog qhov tseem ceeb ntawm cov khoom sib khi.

4. TPU (PU)
Polyurethane feem ntau hu ua TPU hauv kev sib khi daim ntaub ntawv thiab yog cov khoom siv hauv hydraulic dynamic sealing. Parker TPU tau ua tus qauv ntsuas hauv cov tshuab hluav taws xob rau lub sijhawm ntev, muab qhov tshwj xeeb hnav tsis kam, thermal stability, hydrolysis tsis kam, compression teeb ua haujlwm thiab elastic rov qab. Covestro kuj tseem sau nws qhov kev ua kom puas tsuaj zoo, 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 muaj elasticity zoo heev thiab zoo heev txhim kho cov hnav lub neej thiab cov neeg kho tshuab durability, tshwj xeeb tshaj yog rau siab - siab dynamic hydraulic daim ntaub ntawv. Tab sis nws lub zog tiag tiag yog tshwj xeeb hauv dynamic hydraulic sealing, tsis yog nyob rau hauv universal tshuaj tsis kam los yog zoo li qub sealing tej yam kev mob.

Ib qho kev xav tsis zoo tshaj plaws yog xav txog TPU ua ib yam khoom sib xws, vim tias nws cov tshuaj tiv thaiv muaj zog heev nyob ntawm kev tsim, hardness, kub, concentration thiab lub sij hawm raug. Muaj zog acids thiab alkalis yuav tawm tsam TPU, muaj ntxhiab hydrocarbons yuav ua rau nws o, ketones thiab esters yuav ua rau muaj kev o, thiab DMF, DMSO, NMP, thiab THF yog cov kuab tshuaj rau TPU. Lub formulation kuj muaj lub luag hauj lwm nyob rau hauv kub tsis kam. MDI raws li cov txheej txheem ib txwm nyob ntawm 100℃thaum PPDI raws li nyob ib ncig ntawm 135 degree. Li no, PU tsis yog txiav txim los ntawm ib tug ciam teb tas mus li, tab sis los ntawm qhov system- nyob ntawm tus ciam teb tsim.

5. Engineering txwv ntawm elastomers thiab engineering plastics
Lub hauv paus txheej txheem ntawm engineering plastics thiab elastomers tuaj yeem nkag siab ob peb txoj hauv kev. Elastomers feem ntau yog lub luag hauj lwm rau lub 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 thawb cov kev ua tau zoo txwv nrog tsis tshua muaj kev sib txhuam, hnav tsis kam, tshuaj tiv thaiv, extrusion tsis kam thiab seem stability.

Lawv lub luag haujlwm ua haujlwm tau zoo sib txawv. PTFE feem ntau cuam tshuam nrog kev txwv tshuaj, kub thiab kev sib txhuam. UHMWPE muaj kev txhawj xeeb nrog kev hnav tsis kam, kev taw qhia, kev ua haujlwm kub tsis tshua muaj siab thiab qis qis. PEEK yog siv los thauj cov kabmob, tiv thaiv -extrusion thiab kev kub siab kev ruaj ntseg. 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 yog feem ntau tsis hloov tab sis hybrid systems. Piv txwv li, ib lub nplhaib O- lub nplhaib muab kev sib txuas ua ntej thiab kev sib tiv tauj thawj zaug, lub tes tsho PTFE muab kev sib txhuam thiab txhim kho cov tshuaj tiv thaiv, thiab PEEK lossis puv PTFE rov qab- lub nplhaib tuaj yeem tiv thaiv kev sib tsoo hauv qab siab.

Qhov feem ntau yuam kev engineering yog sib piv cov ntaub ntawv rau ntau txoj kev sib khi. PTFE tsis yog siab -kawg roj hmab, PEEK tsis yog yas yas, UHMWPE tsis yog PTFE pheej yig, PU tsis yog ib qho nyuaj NBR xwb. Thaum pom qhov tseem ceeb tsis ua hauj lwm hom yog pom, cov ntaub ntawv ciam teb yog pom tseeb.