Colorability ntawm PVC

PVC tsis zoo thermal stability thiab lub teeb tsis kam. Hydrogen chloride pib decompose ntawm 150 degree, thiab cov kev phiv tshwm sim tshwm sim nrog tus nqi ntawm plasticizer. Tsis tas li ntawd, kev cuam tshuam ntawm cov xim ntawm PVC yog xav txog seb cov xim puas cuam tshuam nrog PVC thiab lwm yam khoom ntawm PVC, thiab kev tsiv teb tsaws tsis kam thiab kub tsis kam ntawm cov xim nws tus kheej. Qee cov khoom siv hauv cov xim tuaj yeem txhawb kev degradation ntawm cov resin. Piv txwv li, hlau ions thiab zinc ions yog catalysts rau degradation ntawm PVC resin. Yog li ntawd, kev siv hlau oxide (liab, daj, xim av thiab dub) pigments los yog xim dawb xws li zinc oxide, zinc sulfide thiab lithopone yuav txo qhov thermal stability ntawm PVC resin. Qee cov xim tuaj yeem ua rau cov khoom degradation ntawm PVC resin. Piv txwv li, cov xim ultramarine muaj cov kua qaub tsis zoo, yog li lawv yuav cuam tshuam nrog hydrogen chloride tsim los ntawm PVC decomposition thiab poob lawv cov xim zoo thaum lub sijhawm xim PVC. Yog li ntawd, raws li PVC xim muaj kev txhawj xeeb, cov yam ntxwv ntawm resins thiab lwm yam additives siv thiab cov yam ntxwv ntawm pigments yog xam. Cov teeb meem hauv qab no yuav tsum raug sau tseg thaum xaiv cov xim xim.
1. Qee cov hlau ions hauv cov xim tuaj yeem txhawb cov thermal oxidative decomposition ntawm PVC resin.
Txoj kev txiav txim siab yog cov xim hloov ntawm polyethylene nrog cov xim thaum rhuab mus rau 180 degree. Raws li cov xim muaj hlau ions, qhov decomposition ntawm PVC yog nrawm, ua rau cov xim hloov. Nyob rau tib lub sijhawm, nws yuav tsum raug sau tseg tias qhov sib ntxiv ntawm lub pas dej liab tuaj yeem ua rau cov xim sib txawv ntawm PVC sib txawv. Yog tias muaj calcium, cov xim sib txawv me me; Cov xim sib txawv yog qhov loj thaum muaj manganese, uas yog vim kev txhawb nqa ntawm dehydrochlorination ntawm PVC los ntawm manganese thiab lwm yam hlau.
Sulfide colorants (xws li cadmium liab) yog siv rau xim PVC, uas yuav tso tawm hydrogen sulfide vim decomposition ntawm colorants. Cov xim zoo li no yuav tsum tsis txhob sib xyaw nrog cov hmoov txhuas stabilizer kom tsis txhob ua cov hmoov lead sulfide.
2. Cov nyhuv ntawm cov xim ntawm cov hluav taws xob rwb thaiv tsev ntawm PVC
Raws li cov ntaub ntawv cable, PVC thiab polyethylene yuav tsum xav txog cov khoom hluav taws xob tom qab xim. Tshwj xeeb, PVC muaj cov rwb thaiv tsev zoo dua li polyethylene, yog li cov xim ntawm cov xim muaj ntau dua. Nws qhia tau hais tias cov hluav taws xob rwb thaiv tsev ntawm PVC dyed nrog inorganic pigments yog zoo dua li cov organic pigments (tshwj tsis yog rauv dub thiab anatase titanium dioxide).