Kev piav qhia ntxaws txog kev siv tshuab degreasing rau hlau hmoov txhaj tshuaj molding
Ua ntej ntawm tag nrho cov, hlau hmoov txhaj tshuaj molding yog kom uniformly sib tov khoom hmoov thiab organic binder. Tom qab granulation, nws yog txhaj rau hauv pwm kab noj hniav los ntawm kev txhaj tshuaj molding tshuab kom solidify thiab daim ntawv, thiab tom qab ntawd cov tsim dawb paug yog chemically los yog thermally decomposed. Cov binder raug tshem tawm hauv cov khoom kawg los ntawm sintering thiab densification.
Cov txheej txheem ntawm degreasing nyob rau hauv hlau hmoov txhaj molding muaj xws li thermal decomposition, hnyav degreasing, catalytic degreasing, thiab lwm yam. Ntawm lawv, cov khoom tsim tom qab catalytic degreasing muaj qhov tseeb qhov tseeb, thiab peb lub tuam txhab txais catalytic degreasing.
Noj polyoxymethylene (POM) binder ua piv txwv, cov txheej txheem degreasing tau muab faib ua peb theem: ua ntej- yaug, degreasing thiab tom qab- yaug.
Ua ntej- yaug theem: Txij li cov khoom degreasing ntawm cov hmoov hlau txhaj tshuaj molding ntsuab embryo yuav hnov mob nrog oxygen, huab cua nyob rau hauv lub cub tawg yuav tsum tau diluted ua ntej degreasing, thiaj li hais tias cov ntsiab lus nyob rau hauv cov pa oxygen mus txog ib tug zoo nqi. Hauv lub sijhawm ua ntej -flushing, lub qhov cub tawg, lub raj xa dej thiab cov kav dej nitrogen yuav ua kom sov, thiab cov kiv cua hauv qhov cub yuav pib tib lub sijhawm kom xa nitrogen mus rau hauv qhov cub.
Degreasing theem: yog hais txog cov txheej txheem uas cov binder (polyoxymethylene) nyob rau hauv cov nqaij nyoos embryo nyob rau hauv lub qhov cub degreasing yog decomposed rau hauv formaldehyde ntawm qhov kub thiab txias. Lub cub tawg yog nyob rau hauv lub tshav kub preservation, lub twj tso kua mis nitric acid pib, thiab nitric acid yog txhaj rau hauv lub qhov cub. Nyob rau hauv cov huab cua acidic, qhov decomposition cov tshuaj tiv thaiv ntawm polyoxymethylene yog nrawm.
Tom qab-luaj theem: Tom qab lub degreasing theem dhau lawm, nitrogen pib mus rau hauv lub cub tawg kab noj hniav, thiab cov formaldehyde thiab nitric acid uas tsim nyob rau hauv lub cub tawg los ntawm lub degreasing theem yog tawm los ntawm lub cua sov raj. Formaldehyde thiab nitric acid yuav tsum tau rhuab thiab hlawv nyob rau hauv lub raj, thiab tsuas yog carbon dioxide, dej vapor thiab nitrogen dioxide yuav thaum kawg tawm mus rau lub ntiaj teb no. Cov no yog cov pa roj uas ua rau huab cua thiab ua tau raws li kev tiv thaiv ib puag ncig.
Tus nqi degreasing ntawm cov hmoov hlau txhaj tshuaj molding ntsuab embryo tom qab catalytic degreasing yog siab li 90 feem pua, thiab nws dhau los ua grey dawb paug. Cov theem tom ntej yog nkag mus rau qhov cub sintering rau sintering.
