Vim tias cov khoom siv PVC ua tau zoo heev nrog PVC thiab muaj qhov hnyav ntawm qhov hnyav (kwv yees (1-2) × 105-2.5 × 106g / mol) thiab tsis muaj cov hmoov txheej, lawv yuav raug tshav kub thiab sib tov thaum lub sij hawm molding txheej txheem. Lawv xub soften thiab nruj nreem khi cov resin hais ib puag ncig. Los ntawm kev sib txhuam thiab kub hloov mus, melting (gel) yog nce. Lub viscosity ntawm yaj tsis txo qis, lossis txawm nce; Vim lub entanglement ntawm molecular chains, lub elasticity, lub zog, thiab extensibility ntawm PVC tau zoo tuaj.
Tsis tas li ntawd, vim qhov tseeb tias qhov sib xws thiab tsis sib xws ntawm PVC tsim kev pab cuam nrog cov qauv ntawm lub plhaub. Raws li ib tug tag nrho, nws yog incompatible nrog PVC thiab yog li ntawd ua hauj lwm pab raws li ib tug sab nraud lubricant, tab sis tsis precipitate thiab daim ntawv teev, uas muaj ib tug ncua sij hawm ntawm melting. Yog li ntawd, raws li cov yam ntxwv ntawm daim ntawv thov no, PVC kev pab cuam yuav muab faib ua ob pawg: universal thiab lubricating. Kev ua haujlwm ntawm cov khoom siv dav siv hauv PVC yog los txo qhov kub thiab txias, txhim kho thermal zog thiab kev sib xws, txo cov pob txha tawg, thiab ua kom cov ductility ntau dua. Cov haujlwm no muaj cov txiaj ntsig zoo rau kev ua haujlwm PVC: txo qhov kub thiab txias txhais tau tias ncua sij hawm thermal stability, muab kev nyab xeeb rau kev siv cov khoom siv rov ua dua tshiab, thiab tso cai rau kev ua haujlwm ntxiv; Txhim kho thermal lub zog thiab txo cov pob txha tawg, uas txhais tau hais tias nws tuaj yeem ua kom nrawm nrawm, ua kom nrawm nrawm, thiab tseem txhim kho qhov pom tseeb thiab tsim tau; Txhim kho qhov sib xws ntawm cov yaj, uas tuaj yeem txo qis qhov ripples thiab yaj rupture ntawm cov khoom extruded, yog li ua kom cov khoom tsim tau zoo, txhim kho ductility thiab thermoformability.
Post lub sij hawm: Sep-05-2024
