1. PVC tsis tshua muaj thermal stability
PVC decomposes yooj yim thaum rhuab, tso hydrogen chloride gas. Thaum qhov kub siab tshaj nws qhov kev nyab xeeb sab sauv (feem ntau yog 190-200 degree), decomposition nrawm nrawm, ua rau cov khoom siv char, blacken, thiab emit pa luam yeeb, thiab tej zaum yuav corrode cov khoom thiab pwm.
2. Lub qhov rais melting kub yog nqaim heev
Kev ua haujlwm kub ntau rau PVC tsuas yog kwv yees li 140-190 degree, nrog rau qhov zoo tagnrho rau kev tsim khoom ruaj khov feem ntau tsuas yog 10-20 degree. Hauv qab qhov txwv qis (<140°C), plasticization is incomplete; above the upper limit (>200 degree), decomposition tshwm sim tam sim ntawd. Tsis muaj npoo rau qhov yuam kev.
3. Qhov zoo ntawm cov txheej txheem plasticization ncaj qha txiav txim siab kev ua haujlwm ntawm cov yeeb nkab.
Yog tias qhov kub thiab txias dhau lawm: Cov khoom siv tsis yaj txaus, tawm hauv cov hmoov tsis zoo thiab cov khoom hauv cov yeeb nkab. Qhov no ua rau muaj qhov txo qis hauv kev cuam tshuam lub zog, lub nplhaib txhav, thiab kev ua haujlwm siab, ua rau cov yeeb nkab ua kom tawg thiab tawg.
Yog tias qhov kub thiab txias heev: cov khoom overheats thiab decomposes, ua rau cov pob dub, daj streaks, thiab npuas tshwm rau ntawm cov yeeb nkab nto, nrog rau cov pores hauv cov yeeb nkab. Qhov no ua rau muaj kev puas tsuaj loj heev hauv cov khoom siv kho tshuab, uas ua rau cov yeeb nkab tawg thaum muaj kev cuam tshuam me ntsis.
4. Kev cuam tshuam rau qhov tseeb thiab qhov tshwm sim
Qhov kub hloov pauv ua rau muaj kev hloov pauv hauv yaj viscosity, ua rau muaj kev hloov pauv hauv extrusion siab. Qhov no ua rau cov phab ntsa tuab tsis sib xws, ntau dhau txoj kab sib txawv, qhov ntxhib nto, thiab tsis muaj luster, ua rau cov khoom tsis tuaj yeem ua tau raws li lub teb chaws cov qauv thiab cov neeg siv khoom.
5. Muaj kev nyab xeeb thiab ib puag ncig kev pheej hmoo
Cov roj hydrogen chloride ua los ntawm thermal decomposition yog tshuaj lom thiab corrosive. Nws tsis tsuas yog ua rau muaj kev phom sij rau kev noj qab haus huv ntawm cov neeg ua haujlwm tab sis kuj ua rau cov khoom siv corrodes (xws li cov ntsia hlau, cov thoob, thiab pwm), ua rau lub tshuab ua haujlwm ntev. Tsis tas li ntawd, lub tuam txhab tuaj yeem raug nplua rau ib puag ncig vim muaj kev tso tawm ntau dhau.
6. Cov Nqi Nyiaj Txiag Siab
Kev tswj tsis tau qhov kub thiab txias ncaj qha ua rau cov khoom tsis raug, nkim raw khoom thiab hluav taws xob. Kev kaw tsis tu ncua rau kev ntxuav decomposition byproducts, hloov cov lim dej, thiab kho cov cuab yeej kho kom txo tau cov khoom tsim tawm. Cov ntaub ntawv kev lag luam qhia tau hais tias kwv yees li 30% ntawm cov teeb meem zoo hauv PVC yeeb nkab ntau lawm muaj feem xyuam rau kev tswj qhov kub thiab txias.