Abstract: Txheeb xyuas cov txheej txheem cuam tshuam cov txheej txheem ntawm cov khoom tsis zoo ntawm cov roj hmab nitrile (NBR) cov khoom lag luam. Cov txheej txheem tseem ceeb ntawm cov khoom tsis zoo hauv NBR cov khoom lag luam yog: cov txheej txheem kev sib xyaw, kev sib xyaw ua ke, cov khoom sib xyaw ua ke, lub sijhawm khaws cia, qhov loj me me, cov qauv pwm thiab qhov pom kev sib txawv, ua kom qhov kub thiab txias, ua kom lub siab thiab kho lub sijhawm. Kev ntsuas hom phiaj tuaj yeem daws cov teeb meem zoo ntawm NBR cov khoom lag luam.
NBR yog siv rau hauv kev npaj cov khoom siv roj hmab. Raws li qhov kub nce ntxiv thiab cov ntsiab lus acrylonitrile nce, NBR thermoplasticity nce. Cov ntaub ntawv zoo thermoplastic muaj fluidity zoo thiab yog qhov tsim nyog rau kev npaj cov khoom pwm. Cov khoom siv roj hmab ua tiav pwm yog tsim los ntawm kev sib xyaw qee cov duab thiab qhov zoo ntawm cov roj hmab sib xyaw rau hauv cov pwm, vulcanizing nws ntawm lub tiaj phaj vulcanizing tshuab, thiab tom qab ntawd demolding thiab txiav. Qhov zoo ntawm cov khoom siv roj hmab pwm feem ntau txiav txim siab los ntawm roj hmab mis thiab kev ua tshuab. Tshooj lus no tsuas yog tham txog cov txheej txheem txheej txheem uas cuam tshuam rau qhov zoo ntawm NBR pwm khoom.
1. Cov khoom siv tsis xws luag ntawm NBR pwm khoom
Lub hom phiaj molding yog ua kom cov khoom siv roj hmab muaj qee yam duab thiab lub cev, thiab tsis txhob muaj qhov tsis zoo saum npoo av. Cov khoom siv tsis zoo ntawm NBR cov khoom lag luam muaj raws li hauv qab no: kev sib dua ntawm cov kab ib tog, ntws cov cim rau saum npoo, tsis-du, txhav, nqa lossis yob, tawv nqaij tawg, sab hauv cov huab cua ua npuas, ntau cov shrinkage nyob rau hauv qhov loj me, thiab demolding A nick yog tsim.
2 · Qhov ua rau cuam tshuam qhov zoo ntawm NBR pwm khoom
Kev npaj ntawm NBR moulded cov khoom lag luam yuav tsum them sai sai rau cov xwm txheej xws li kev sib xyaw ua tiav roj hmab, pwm tsim thiab kho cov teeb meem.
2.1 Npaj roj hmab sib txuas
2.1.1 Kev sib xyaw cov txheej txheem
不良 Kev tsis zoo ntawm kev sib txuam ua ke yuav cuam tshuam rau lub cev lub zog ntawm NBR cov khoom pwm. Piv txwv li, leej faj daj muaj solubility tsawg hauv NBR, thiab nws tsis yooj yim rau tawg. Nws feem ntau ua rau tev tawm los yog nplais ntawm lub ntsej muag thaum cov khoom siv roj hmab raug rhuav tshem, thiab cov nplaim hluav taws tuaj yeem pom thaum lub vulcanizate ncav us txog. Kev tsis sib haum ntawm cov tshuab yas yuav ua rau muaj qhov sib xyaw kom zoo ua ntej molding, ua kom muaj huab cua npuas, thiab txo qhov kev coj ua tsis zoo ntawm cov pa roj carbon peroxide sib txuas. Kev cuam tshuam nyob rau hauv tus neeg sawv cev ua cov tshuaj tiv thaiv tuaj yeem ua rau cov roj hmab xoob xoob xaim thiab cov khoom tsis zoo ntawm cov khoom lag luam precision. Cov khoom sib xyaw tsis txaus yuav tsum rov muab hloov dua nyob rau hauv lub sijhawm. Scorched roj hmab cov khoom yog qhov nyuaj rau ntws thaum lub sij hawm molding vulcanization txheej txheem. Kev ua kom tawg ntawm cov khoom siv roj hmab tuaj yeem ua rau muaj kev tsis xws li kev cog lus, lub cev tsis zoo, lub caws thiab cuam tshuam.
2.1.2 Cov roj hmab viscosity
Cov npliag ntawm cov roj hmab txuas hauv cov kab noj hniav yog nyob ntawm qhov viscosity ntawm cov roj hmab compounded. Lub viscosity ntawm NBR compound feem ntau txiav txim siab los ntawm lub hnab yas thiab muab tub lim. Nws yog qhov nyuaj heev kom txo qhov viscosity ntawm cov roj hmab siv cov hnab yas los yog lub sijhawm ntev mus. Lub Mooney viscosity [ML (1 + 4) 100 ° C] ntawm NBR roj hmab rau cov txheej txheem molding yog 35 txog 130. Yog tias viscosity ntawm cov khoom siv roj hmab yog qhov me me thiab qhov vulcanization siab tsis txaus, cov khoom yuav tsim npuas thaum lub sijhawm vulcanization; yog tias cov roj hmab viscosity loj heev, nws tsis yooj yim los sau cov pwm thaum lub sijhawm vulcanization, thiab cov khoom lag luam yuav ua rau cov roj hmab tsis txaus lossis ua cov tawv nqaij.
2.1.3 Kev rho tawm ua yeeb yaj kiab
Txhawm rau txhawm rau tiv thaiv kom tsis txhob thaiv, cov tso tawm tso tawm tuaj yeem pleev xim rau sab saum toj ntawm zaj duab xis thaum NBR compound roj hmab raug txo qis, tab sis cov kua roj stearic acid tsis tuaj yeem siv vim tias stearic acid tsis zoo nyob rau hauv NBR thiab yuav ua si lub luag haujlwm lubrication ntau dhau, uas yuav cuam tshuam cov roj hmab thaum lub sij hawm molding. Thaum sib khi. Thaum NBR cov tshuaj sib xyaw ua ke nrog cov tub ntxhais hlau, tsis pub siv cov hmoov paug tawm, thiab cov viscosity ntawm qhov chaw tiv tauj nruab nrab ntawm cov sib txuas thiab cov hlau yuav tsum ua kom ntseeg tau.
2.1.4 Cov roj hmab sib xyaw cov chaw nres tsheb
NBR roj hmab yuav tsum tau sab laug rau 16 teev tom qab txhaj tshuaj molding thiab tom qab ntawd pwm. Qhov zoo tshaj plaws lub sijhawm rau kev nres tsheb yog 24 teev. Yog tias cov khoom siv roj hmab tsis nres, npuas thiab pob yuav tshwm ntawm cov khoom; yog tias lub sijhawm nres tsheb yog luv heev, nws yuav cuam tshuam rau cov khoom ntawm lub cev; yog tias lub sijhawm nres tsheb ntev dhau, nws yuav cuam tshuam loj rau kev nplaum ntawm cov khoom siv roj hmab rau cov khoom siv hlau.
2.1.5 Cov roj hmab qhov loj me
Qhov luaj li cas ntawm cov roj hmab compound tsis tuaj yeem sib thooj li qhov loj ntawm cov kab noj coj ua uas sib haum. Qhov zoo ntawm cov roj hmab sib txuas thaum lub sij hawm molding yuav tsum yog ntau dua cov roj hmab ib feem ntawm cov khoom. Kev txeej ntawm cov roj hmab (los yog txeej ntug) thaum lub sij hawm molding yuav ua lub luag haujlwm ob yam hauv kev nthuav tawm cov pa hauv cov pwm kab noj hniav thiab tswj kev ua haujlwm siab vulcanization. nyhuv. Tus nqi ntawm cov flashover yuav tsum nruj tswj hwm raws li cov khoom loj, txoj kev molding thiab pwm qauv. Yog tias cov kua nplaum ntau qhov tsis txaus sau cov pwm kab noj hniav, nws yuav ua rau tsis muaj kua nplaum; yog tias cov kua nplaum ntau dhau, nws yuav tiv thaiv cov pwm ntawm kev kaw thiab ua rau cov khoom lag luam tawm ntawm qhov tsis paub meej. Rau lub dav dav vulcanizing tshuab, cov roj hmab sib txuas ntawm cov pwm sib cais yuav tsum tau sau li 15% -20%, cov roj hmab compound nias rau hauv cov pwm cais yuav tsum tau sau li 5% -10%, thiab cov roj hmab sib txuas ntawm cov laub- hauv pwm yuav tsum tau sau Ntau Txog 2%.
2.2 Pwm Tsim
NBR yog dav siv hauv kev tsim khoom ntawm O-rings, U-rings, ntsaws ruaj ruaj thiab gaskets. Thaum lub siab thev naus laus zis ntawm cov khoom lag luam ntau dhau qhov teev siab kam rau ua, nws lub neej kev pab yuav raug ua kom luv, thiab nws yuav txawm nplawm tom qab ob peb feeb ntawm kev siv. Yog li ntawd, cov qauv tsim pwm yuav tsum ua kom ntseeg tau cov khoom loj.
Lub hauv paus tseem ceeb cuam tshuam rau kev txiav txim siab qhov ntev ntawm cov khoom yog kev txiav tawm ntawm cov roj hmab. Txhaum ntawm cov khoom me me tso cai, lub pwm tsim qauv ua ntej yuav tsum xav txog kev txhav ntawm cov roj hmab. Yog vim li cas rau shrinkage ntawm cov roj hmab compound yog tias cov thermal expansion coefficient ntawm cov roj hmab compound yog ntau dua li ntawm cov khoom siv hlau.
NBR cov khoom lag luam feem ntau muaj qhov siab tsis txaus ntawm 0.5% mus rau 1.0%. Kev tso cai muaj kev zam ntawm cov pwm loj ntawm American cov khoom siv roj hmab pwm yog nyob ntawm cov khoom. Kev kam rau ntawm cov pwm qhov loj ntawm cov khoom siv dav dav yog 0.127 hli, thiab kam rau ua pwm ntawm qhov loj me ntawm cov khoom lag luam tshwj xeeb yog 0.005 hli. Thiab cov duab hloov, cov khoom lag luam ua cov khoom me me muaj qhov txaus siab yog 0. 254 txog 0. 635 hli, daim txhuam cev cov khoom lag luam ua kom muaj qhov ua siab me yog 0. 254 txog 1. 520 hli. Ua ntej tso cua sov ntawm cov roj hmab txuas ua ntej kev rho tawm roj tuaj yeem txo qhov kev hloov kho sab hauv ntawm cov roj hmab sib txuas; tom qab txias, lub shrinkage ntawm cov roj hmab sib txuas ntau tshaj li cov kab noj hniav, thiab cov neeg kawm ntawv ntawm shrinkage nws txawv nrog cov roj hmab muaj pes tsawg leeg (tshwj xeeb yog hom thiab ntau npaum li cas ntawm cov muab tub lim). Cov kev pauv hloov cuam tshuam nrog kev ntxhov siab sab hauv ua ntej cov roj hmab puab. Cov txiaj ntsig ntawm cov muab tub lim rau ntawm qhov ntsws me me ntawm NBR cov khoom lag luam yog qhia hauv Table 1.
Qhov ua kom dhau ntawm txeej tuaj yeem raug rau qhov tsis txaus lossis tsis sib luag ntawm qhov chaw mos, muaj qhov khiav dim me me thiab qhov chaw siab ntau dhau. Raws li cov qauv tsim, qhov ntim ntawm daim tawv-khiav tawm lub qhov yuav tsum yog 15-20 npaug ntawm qhov ntim ntawm cov kab noj hniav kom txaus kom haum rau cov dhau. Yog tias hla dhau qhov yuav tsum tau ua me me, qhov kev ntxhov siab ntawm cov kab noj hniav thiab lub qhov tawm khiav tawm yog qhov me me. Hauv pwm nrog cov kab noj hniav sib tshooj, qhov faib tawm thiab tuab ntawm cov nplauv ntawm cov npoo sib txawv sib txawv raws qhov curing ua kom siab. Feem ntau, cov thermal rhuav lub zog ntawm NBR yog qhov qis dua li ntawm lwm cov nplaim hluavtaws. Yog li no, qhov ntsuas vulcanization ntawm NBR cov khoom lag luam yuav tsum tsim nyog, thiab kev saib xyuas yuav tsum tsis txhob coj los ua daim ntawv thim rov qab thaum cov khoom tiav tiav raug ntab tawm los ntawm pwm. Tsis tas li, cov kua nplaum ntws sib tsoo ntawm ntug yuav tsum muaj ze li 0.4 ~ 3.2 hli kom ze rau qhov kawg ntawm qhov kab noj hniav.
2.3 Vulcanization tej yam kev mob
2.3.1 Vulcanization kub
BRThe compression curing qhov kub ntawm NBR roj hmab feem ntau yog 140 ~ 200 ℃, qhov tshwj xeeb tua qhov kub yog nyob ntawm cov khoom siv lub cev, qhov loj me thiab kev ntsuas ntawm cov khoom. Kev ntsuas kub tsis zoo tuaj yeem txo cov khoom lag luam teeb meem zoo los ntawm scorch thiab pwm ua paug, thiab lwm yam, thiab tseem tuaj yeem ua cov khoom tau txais lub cev zoo dua. Cov khoom lag luam loj hauv nruab nrab xav tau cov txheej txheem vulcanization sib npaug. Ntawm qhov sib txawv ntawm vulcanization kub, cov khoom siv lub cev muaj peev xwm ua tau zoo los ntawm kev kho lub sijhawm vulcanization.
NBR tebchaw tuaj yeem muab kho kom ncaj los ntawm kev siv cov txheej txheem dielectric. Cov txheej txheem ua ntej cua sov tuaj yeem sib txig ua kom cov roj hmab sib txuas ua ntej kev pwm, ua kom nrawm sai sai, thiab tshem cov teeb meem tsis sib xws ntawm vulcanization thiab tsis ntxig ntawm cov khoom tuab. Khoom skew yog tshwm sim los ntawm lub hauv nruab nrab ntawm cov khoom nto tau raug txuas ntxiv los ntawm tshav kub tom qab vulcanization.
BRNBR cov khoom sib xyaw yog vulcanized rau qhov kub thiab txias, thiab txhua kauj ruam ua haujlwm yuav tsum tau ua sai sai. Piv txwv li, qhov sib txuas ua ke tuaj yeem nyob hauv cov kab noj hniav ntawm 153 ℃ rau 2 feeb thiab tom qab ntawd nyem thiab vulcanize. Tsis tas li ntawd, nrog qhov ntsuas kub ntawm kev lim dej siab, pwm nplai yuav tseem nce, yog li ua kom cov pwm tu kom ntau. Pwm fouling feem ntau tshwm sim los ntawm kev txuam nrog ntawm cov kab sib tsoo thiab cov tso tawm cov neeg ua haujlwm.
2.3.2 Vulcanization siab
Vulcanization siab tseem ceeb heev rau qhov zoo ntawm NBR cov khoom. Yog tias lub siab hloov thaum lub sijhawm vulcanization, cov yam ntxwv ntawm lub cev ntawm cov khoom yuav poob qis, yog li lub siab vulcanization yuav tsum khaws ruaj khov. NBR rubber vulcanization siab feem ntau yog 1.4 ~ 3.4 MPa.
Cov roj ntau dhau ntawm cov khoom tiav ua rau cov khoom pov tseg. Cov teeb meem no feem ntau raug ntaus rau pwm tsim, uas yog qhov tseeb los ntawm qhov tsis txaus siab vulcanization siab. Lub cev tsis txaus thaum ua cov txheej txheem molding feem ntau yuav tsim tawm hws, ua npuas sab nraud thiab deformation; ntau dhau qhov siab yuav ua rau distortion.
NBR cov khoom tuaj yeem segmented vulcanized, uas yog, NBR roj hmab yog thawj zaug vulcanized thiab teeb tsa nyob rau hauv lub tshuab vulcanizing tiaj, thiab tom qab ntawd vulcanized hauv ob theem.
2.3.3 Lub Sijhawm Sib Hawm
Vulcanization lub sijhawm yog lub sijhawm uas cov roj hmab sib txuas yog vulcanized hauv pwm kom tau txais qhov ua tau zoo tshaj plaws nyob rau hauv qee qhov ntsuas kub thiab siab. Yog tias lub sijhawm vulcanization ntev dhau, kab nrib pleb yuav tshwm sim thaum cov khoom lag luam tawg, uas tuaj yeem daws los ntawm vulcanization ntawm qhov kub tsawg rau lub sijhawm ntev. Yog tias lub sijhawm ntu ntsig yog luv luv, cov khoom lag luam yog nyob rau hauv leej faj, thiab nws yooj yim dua rau ntawm ntu kab. Nws tuaj yeem daws los ntawm qhov nce ntawm vulcanization kub.
3 · Xaus
Cov xwm txheej cuam tshuam rau qhov zoo ntawm NBR cov khoom lag luam yog kev txwv tsis pub sib xyaw. Thaum cov teeb meem zoo tshwm sim hauv NBR cov khoom lag luam tsim, nws tsis yog yuav tsum tau kho cov txheej txheem tsim, tab sis kuj tseem pom cov laj thawj los ntawm kev sib xyaw ntawm kev sib xyaw roj hmab, kev tsim pwm thiab kev kho kom zoo, thiab hais tawm kev txhim kho ntsuas kom ntseeg tau cov khoom zoo thiab cov txiaj ntsig Cov.