Polyvinyl chloride pipeline formulation yog tsim los ntawm polyvinyl chloride resin thiab additives. Cov additives muab faib ua: kub stabilizer, lubricant, ua modifier, cuam tshuam hloov, muab tub lim, anti-aging agent, colouring agent thiab hais txog.
Dab tsi yog qhov laj thawj tseem ceeb ntawm PVC yeeb nkab blackening?
Vim muaj cov tshuaj chlorine thiab propylene chloride nyob rau hauv cov qauv molecular ntawm PVC, PVC kav yog ib qho yooj yim rau decompose thaum lub sij hawm ua thiab tom qab siv, HCL yog ib qho yooj yim los tsim conjugated ob daim ntawv cog lus, thiab ntau ob daim ntawv cog lus tau tsim, ua rau cov xim hloov ntawm cev. Kev hloov xim yog raws li hauv qab no: Dawb - liab dawb - lub teeb daj - liab - dub (carbonization), yog li PVC zoo, stabilizer zoo (tswj decomposition) thiab koob tshuaj tseem ceeb heev.
Discoloration tshwm sim los ntawm unqualified titanium dioxide
TiO₂ feem ntau los ntawm ob hom qauv: anatase thiab rutile. Vim nws cov qauv sib txawv, siv lub peev xwm thiab kev laus ua haujlwm. TiOO li PVC yeeb nkab, siv TiOO. O2 yuav tsum yog hom rutile. Tab sis vim qee lub tuam txhab tsim TiOO hom. Cov txheej tsis sib xws ntawm qhov chaw (SiO₂, AL₂O₃ organics) ua rau muaj kev hloov pauv yooj yim (greying) hauv TiO₂ photocatalysis. Anatase hom muaj tus nqi qis ntawm 1, 000 yuan ib tuj, thiab tus nqi tuaj yog 20, 000 yuan ib tuj. ~ 4000 yuan).
