Cov tawv nqaij cuav uas ua los ntawm PVC (PVC-AL) tseem yog cov khoom siv tseem ceeb hauv kev kho kom zoo nkauj hauv tsheb, rooj zaum, thiab cov ntaub lag luam vim nws qhov sib npaug ntawm tus nqi, kev ua haujlwm tau zoo, thiab kev hloov pauv zoo nkauj. Txawm li cas los xij, nws cov txheej txheem tsim khoom raug kev txom nyem los ntawm cov teeb meem kev siv tshuab uas muaj keeb kwm hauv cov khoom siv tshuaj lom neeg ntawm cov polymer - cov teeb meem uas cuam tshuam ncaj qha rau kev ua haujlwm ntawm cov khoom, kev ua raws li txoj cai, thiab kev ua haujlwm zoo.
Kev puas tsuaj ntawm thermal: Ib qho teeb meem tseem ceeb ntawm kev ua haujlwm
Qhov tsis ruaj khov ntawm PVC ntawm qhov kub ua haujlwm ib txwm muaj (160–200 ° C) ua rau muaj qhov teeb meem tseem ceeb. Cov polymer no dhau los ntawm dehydrochlorination (HCl tshem tawm) los ntawm kev ua haujlwm ntawm tus kheej, ua rau muaj peb qhov teeb meem cascading:
• Kev cuam tshuam ntawm cov txheej txheem:Cov HCl uas tso tawm yuav ua rau cov khoom siv hlau (calenders, coating dies) xeb thiab ua rau cov PVC matrix gelation, ua rau muaj cov qhov tsis zoo xws li cov blisters saum npoo lossis cov tuab tsis sib npaug.
• Xim ntawm cov khoom:Cov kab ke polyene sib txuas ua ke uas tsim thaum lub sijhawm puas tsuaj ua rau daj lossis xim av, ua tsis tau raws li cov qauv xim nruj rau cov ntawv thov siab.
• Kev poob ntawm cov khoom siv kho tshuab:Kev txiav cov saw hlau ua rau lub network polymer tsis muaj zog, txo cov tawv nqaij lub zog tensile thiab kev tiv thaiv kev rhuav tshem txog li 30% hauv cov xwm txheej hnyav.
Kev Nyuaj Siab Txog Kev Ua Raws Cai Ib puag ncig thiab Kev Cai Lij Choj
Kev tsim khoom PVC-AL ib txwm muaj kev tshuaj xyuas ntau ntxiv raws li cov cai thoob ntiaj teb (piv txwv li, EU REACH, US EPA VOC cov qauv):
• Cov pa phem ntawm cov organic compound (VOC):Kev puas tsuaj los ntawm cua sov thiab kev siv cov tshuaj plasticizer uas muaj cov kuab tshuaj tso tawm cov VOCs (piv txwv li, phthalate derivatives) uas tshaj qhov tso pa tawm.
• Cov hlau hnyav seem:Cov txheej txheem tswj kev ruaj khov qub (piv txwv li, cov hlau lead, cadmium-based) tso cov pa phem me ntsis, ua rau cov khoom tsis tsim nyog los ntawm cov ntawv pov thawj eco-label (piv txwv li, OEKO-TEX® 100).
• Kev siv rov qab tau thaum kawg ntawm lub neej:PVC uas tsis ruaj khov yuav lwj ntxiv thaum lub sijhawm siv tshuab rov ua dua tshiab, tsim cov tshuaj lom thiab txo qhov zoo ntawm cov khoom siv rov ua dua tshiab.
Kev Siv Tau Ntev Tsis Zoo Hauv Cov Kev Pabcuam
Txawm tias tom qab tsim khoom, PVC-AL tsis ruaj khov kuj tseem laus sai dua:
• Kev puas tsuaj los ntawm UV:Lub hnub ci ua rau muaj kev sib txuas ntawm cov duab photo-oxidation, rhuav cov saw polymer thiab ua rau brittleness—qhov tseem ceeb rau cov rooj zaum hauv tsheb lossis sab nraum zoov.
• Kev hloov pauv ntawm cov khoom siv yas:Yog tsis muaj cov khoom siv stabilizer-mediated matrix reinforcement, cov plasticizers yuav leach raws sijhawm, ua rau tawv thiab tawg.
Lub Luag Haujlwm Tseem Ceeb ntawm PVC Stabilizers: Cov Txheej Txheem thiab Tus Nqi
Cov stabilizers PVC hais txog cov teeb meem no los ntawm kev tsom mus rau txoj kev puas tsuaj ntawm qib molecular, nrog rau cov qauv niaj hnub muab faib ua pawg ua haujlwm:
▼ Cov Khoom Siv Thermal Stabilizers
Cov no ua haujlwm ua HCl scavengers thiab chain terminators:
• Lawv ua kom cov HCl uas tso tawm tsis muaj zog (los ntawm kev sib xyaw nrog cov xab npum hlau lossis cov organic ligands) kom nres autocatalysis, ua kom lub sijhawm ua haujlwm ruaj khov ntev li 20-40 feeb.
• Cov tshuaj organic co-stabilizers (piv txwv li, cov phenols uas raug cuam tshuam) ntes cov free radicals uas tsim tawm thaum lub sijhawm rhuav tshem, khaws cia qhov ruaj khov ntawm cov saw molecular thiab tiv thaiv kev hloov pauv xim.
▼ Cov Khoom Siv Tiv Thaiv Lub Teeb
Ua ke nrog cov tshuab thermal, lawv nqus lossis tshem tawm lub zog UV:
• Cov tshuaj nqus UV (piv txwv li, benzophenones) hloov cov hluav taws xob UV mus ua cua sov tsis muaj teeb meem, thaum cov tshuaj hindered amine light stabilizers (HALS) rov ua dua cov polymer uas puas lawm, ua rau cov khoom siv sab nraum zoov siv tau ntev ob npaug.
▼ Cov Qauv Uas Zoo Rau Ib Puag Ncig
Cov tshuaj stabilizer sib xyaw ua ke ntawm calcium-zinc (Ca-Zn)tau hloov cov hlau hnyav sib txawv, ua tau raws li cov cai tswjfwm thaum tseem tswj tau qhov ua tau zoo. Lawv kuj txo cov pa phem VOC los ntawm 15–25% los ntawm kev txo qis kev puas tsuaj thermal thaum lub sijhawm ua haujlwm.
Cov Stabilizers Ua Ib Qho Kev daws teeb meem tseem ceeb
Cov tshuaj stabilizer PVC tsis yog tsuas yog cov khoom ntxiv xwb—lawv yog cov khoom uas ua rau PVC-AL tsim tau zoo. Los ntawm kev txo qhov kub thiab txias, ua kom ntseeg tau tias ua raws li txoj cai, thiab txhim kho kev ruaj khov, lawv daws qhov teeb meem ntawm cov polymer. Txawm li cas los xij, lawv tsis tuaj yeem daws txhua qhov teeb meem hauv kev lag luam: kev nce qib hauv cov khoom siv yas bio-based thiab kev siv tshuaj rov ua dua tshiab tseem ceeb heev kom phim PVC-AL nrog lub hom phiaj kev lag luam ncig. Txawm li cas los xij, tam sim no, cov txheej txheem stabilizer zoo tshaj plaws yog txoj hauv kev paub tab tshaj plaws thiab pheej yig tshaj plaws rau cov tawv nqaij PVC zoo, ua raws li txoj cai.
Lub sijhawm tshaj tawm: Kaum Ib Hlis-12-2025