High density polyethylene txheej txheem ntau lawm

Cov txheej txheem ntau lawm ntawm PE yog los ntawm slurry lossis roj theem ua, thiab ob peb yog tsim los ntawm kev daws teeb meem theem. Tag nrho cov txheej txheem no yog exothermic cov tshuaj tiv thaiv nrog ethylene monomer, alpha-olefin monomer, catalyst system (uas yuav muaj ntau tshaj li ib qho kev sib xyaw) thiab ntau hom hydrocarbon diluents. Hydrogen thiab qee cov catalysts yog siv los tswj qhov hnyav molecular. Lub slurry reactor feem ntau yog lub tank stirred los yog siv ntau tshaj qhov loj-scale annular reactor nyob rau hauv uas cov slurry yuav tsum circulated thiab stirred. Polyethylene hais yog tsim thaum ethylene thiab comonomer (yog tias xav tau) tuaj rau hauv kev sib cuag nrog lub catalyst. Tom qab tshem tawm cov diluent, cov polyethylene granules los yog hmoov yog qhuav thiab additives yog dosed los tsim pellets. Cov kab ntau lawm niaj hnub nrog cov reactors loj nrog ntxaib-ntsia hlau extruders muaj peev xwm ua tau ntau tshaj 40,000 phaus PE ib teev. Txoj kev loj hlob ntawm cov catalysts tshiab pab txhawb kev txhim kho cov qib tshiab ntawm HDPE. Ob hom catalyst feem ntau siv yog Philips 'chromium oxide-based catalysts thiab titanium compound-alkyl aluminium catalysts. HDPE ua nrog Phillips-hom catalysts muaj qhov nruab nrab-dav molecular hnyav faib; titanium-alkylaluminium catalysts tsim nqaim molecular hnyav faib. Tib cov catalysts siv los tsim nqaim MDW polymers hauv duplex reactors tuaj yeem siv los tsim cov qib MDW dav. Piv txwv li, ob lub reactors nyob rau hauv series tsim cov khoom ntawm qhov sib txawv molecular luj tuaj yeem tsim bimodal molecular hnyav polymers nrog ntau yam ntawm cov khoom hnyav molecular.