pev

Tshuab Luam Ntawv

Ntxiv rau qhov ntshiab (homopolymer) PET, tus tsiaj hloov los ntawm copolymerization kuj muaj.

Muaj qee kis, cov khoom raug hloov kho ntawm copolymer yog qhov tsim nyog dua rau ib daim ntawv thov tshwj xeeb. Piv txwv li, Cyclohexane dimethanol (CHDM) tuaj yeem raug ntxiv rau polymer pob txha caj qaum ethylene glycol hmoovCov. Txij li thaum lub tsev thaiv no yog ntau dua (6 ntxiv carbon atoms) dua li cov ethylene glycol chav nws hloov, nws tsis haum rau nrog cov hlua sib txuas ib puag ncig ntawm txoj kev ib qho kev sib koom ua ke ethylene glycol. Qhov no cuam tshuam nrog crystallization thiab qis qis dua polymer lub siab kub. Feem ntau, xws li PET yog lub npe hu ua PETG lossis PET-G (Polyethylene terephthalate glycol-hloov kho; Eastman Tshuaj, SK Tshuaj, thiab Artenius Italia yog qee cov PETG manufacturers). PETG yog tus ntshiab amorphous thermoplastic uas tuaj yeem raug txhaj tshuaj moulded lossis daim ntawv extruded. Nws tuaj yeem yog xim thaum lub sijhawm ua haujlwm.

Lwm qhov hloov kho yog isophthalic acid, hloov qee yam ntawm 1,4- (kev) sib txuas terephthalate chav nyob. Lub 1,2- (ortho-) lossis 1,3- (lub hom phiaj-) kev sib txuas ua rau lub kaum ntse ntse nyob hauv cov saw, uas kuj cuam tshuam rau cov neeg sab nraud.

Xws li cov tshuab luam ntawv tau zoo rau qee qhov kev siv tshuaj molding, xws li thermoforming, uas yog siv piv txwv li ua lub tais los yog cov hlwv ntim los ntawm co-PET zaj duab xis, lossis amorphous PET ntawv (A-PET) lossis PETG ntawv. Ntawm qhov tod tes, crystallization yog qhov tseem ceeb hauv lwm daim ntawv thov qhov twg kev siv tshuab thiab qhov ntev seem yog qhov tseem ceeb, xws li siv txoj siv sia. Rau cov tsiaj fwj, cov tshuaj siv me me ntawm isophthalic acid, CHDM, diethylene glycol cov (DEG) lossis lwm tus tsim nyog tuaj yeem muaj txiaj ntsig: yog tias tsuas yog siv hluav taws xob me me xwb, kev siv lead ua qeeb qeeb tab sis tsis tiv thaiv nkaus. Raws li qhov tshwm sim, fwj tau tsim los ntawm ncab tshuab moulding ("SBM"), uas yog ob qho tib si meej thiab ci ntsa iab txaus los ua ib qho laj kab txaus rau cov pa tsw qab thiab txawm muaj roj, xws li carbon dioxide nyob rau hauv cov dej haus.