Pulasitiki ya PVC imapangidwa kuchokera ku mpweya wa acetylene ndi hydrogen chloride, kenako ndi polymerized.Kumayambiriro kwa zaka za m'ma 1950, idapangidwa ndi njira ya acetylene carbide, ndipo kumapeto kwa zaka za m'ma 1950, idatembenukira ku njira ya ethylene oxidation yokhala ndi zipangizo zokwanira komanso zotsika mtengo;Pakalipano, oposa 80% a PVC resins padziko lapansi amapangidwa ndi njira iyi.Komabe, pambuyo pa 2003, chifukwa cha kukwera kwa mtengo wamafuta, mtengo wa acetylene carbide njira unali pafupifupi 10% wotsika kuposa wa ethylene oxidation njira, kotero kaphatikizidwe ka PVC kunatembenukira ku njira ya acetylene carbide.
PVC pulasitiki ndi polymerized ndi madzi vinilu kolorayidi monoma (VCM) kudzera kuyimitsidwa, odzola, chochuluka kapena njira yothetsera.Njira kuyimitsidwa polymerization wakhala njira yaikulu kubala PVC utomoni ndi ndondomeko okhwima kupanga, ntchito yosavuta, otsika mtengo kupanga, mitundu yambiri mankhwala ndi osiyanasiyana ntchito.Imawerengera pafupifupi 90% yazomera zopanga PVC zapadziko lonse lapansi (homopolymer imawerengeranso pafupifupi 90% yazotulutsa zonse za PVC padziko lonse lapansi).Yachiwiri ndi njira yopaka mafuta, yomwe imagwiritsidwa ntchito popanga utomoni wa PVC.The polymerization reaction imayambitsidwa ndi ma radicals aulere, ndipo kutentha komwe kumakhala 40 ~ 70oc.Zomwe kutentha ndi kuchuluka kwa oyambitsa zimakhudza kwambiri kuchuluka kwa ma polymerization ndi kuchuluka kwa kulemera kwa maselo a PVC utomoni.
Pindani chosankha chophika
The chilinganizo cha mbiri PVC pulasitiki makamaka wapangidwa ndi PVC utomoni ndi zina, amene anawagawa: kutentha stabilizer, lubricant, processing modifier, zimakhudza zosintha, filler, odana ndi ukalamba wothandizila, colorant, etc. Tisanayambe kupanga PVC chilinganizo, tiyenera choyamba. kumvetsetsa magwiridwe antchito a PVC utomoni ndi zina zowonjezera zosiyanasiyana.
1. The utomoni adzakhala pvc-sc5 utomoni kapena pvc-sg4 utomoni, ndiko, PVC utomoni ndi polymerization digiri ya 1200-1000.
2. Dongosolo lokhazikika la kutentha liyenera kuwonjezeredwa.Sankhani molingana ndi zofunikira zenizeni zopanga, ndipo tcherani khutu ku zotsatira za synergistic ndi zotsatira zotsutsana pakati pa zolimbitsa thupi.
3. Zosintha zosintha ziyenera kuwonjezeredwa.Zosintha za CPE ndi ACR zitha kusankhidwa.Malinga ndi zigawo zina mu chilinganizo ndi mphamvu plasticizing wa extruder, kuchuluka kuwonjezera ndi 8-12 mbali.CPE ali mtengo otsika ndi osiyanasiyana magwero;ACR ili ndi kukana kukalamba kwakukulu komanso mphamvu ya minofu.
4. Onjezani kuchuluka koyenera mu dongosolo lopaka mafuta.Dongosolo lopaka mafuta limatha kuchepetsa kuchuluka kwa makina okonza ndikupangitsa kuti chinthucho chikhale chosalala, koma kuchulukira kumapangitsa kuti mphamvu ya weld fillet ichepe.
5. Kuwonjezera processing modifier akhoza kusintha plasticizing khalidwe ndi kusintha maonekedwe a mankhwala.Nthawi zambiri, ACR processing modifier imawonjezedwa mu kuchuluka kwa magawo 1-2.
6. Kuonjezera zodzaza kungathe kuchepetsa mtengo ndikuwonjezera kukhwima kwa mbiri, koma kumakhudza kwambiri mphamvu yotsika kutentha.Kuwala kashiamu carbonate ndi fineness mkulu ayenera kuwonjezeredwa, ndi kuwonjezera kuchuluka kwa 5-15 mbali.
7. Mulingo wina wa titaniyamu woipa uyenera kuwonjezeredwa ku cheza cha ultraviolet.Titaniyamu woipa ayenera kukhala rutile mtundu, ndi Kuwonjezera kuchuluka kwa 4-6 mbali.Ngati ndi kotheka, ultraviolet absorbers UV-531, uv327, etc. akhoza kuwonjezeredwa kuonjezera kukana ukalamba wa mbiri.
8. Kuonjezera kuwala kwa buluu ndi fulorosenti moyenerera kumatha kusintha kwambiri mtundu wa mbiriyo.
9. Njirayi iyenera kukhala yophweka momwe zingathere, ndipo zowonjezera zamadzimadzi siziyenera kuwonjezeredwa momwe zingathere.Malingana ndi zofunikira za ndondomeko yosakaniza (onani vuto losakaniza), ndondomekoyi iyenera kugawidwa muzinthu I, zakuthupi II ndi zakuthupi III m'magulu malinga ndi ndondomeko yodyetsa, ndikuyika motsatira.
Apangidwe kuyimitsidwa polymerization
Kuyimitsidwa polymerization amasunga umodzi thupi madzimadzi m'malovu inaimitsidwa m'madzi ndi mosalekeza yogwira mtima, ndi polymerization anachita ikuchitika m'malovu ang'onoang'ono monomer.Kawirikawiri, kuyimitsidwa polymerization ndi intermittent polymerization.
M'zaka zaposachedwapa, makampani mosalekeza kuphunzira ndi bwino chilinganizo, polima, zosiyanasiyana mankhwala ndi khalidwe ya pakaimitsa kuyimitsidwa polymerization ndondomeko ya PVC utomoni, ndi kupanga umisiri ndondomeko ndi makhalidwe awo.Pakalipano, luso la kampani ya Geon (kampani yakale ya BF Goodrich), teknoloji ya kampani ya shinyue ku Japan ndi ukadaulo wa kampani ya EVC ku Europe imagwiritsidwa ntchito kwambiri.Ukadaulo wamakampani atatuwa umapanga pafupifupi 21% ya mphamvu zatsopano zopangira utomoni za PVC kuyambira 1990.
Nthawi yotumiza: Jul-15-2022