Chiyambi cha thovu la thovu la polyurethane lomwe limagwiritsidwa ntchito pomanga
Ndi kuchuluka kwa zofunikira za nyumba zamakono zopulumutsa mphamvu ndi kuteteza chilengedwe, ntchito yotenthetsera kutentha kwa zipangizo zomangira imakhala yofunika kwambiri. Pakati pawo, chithovu cholimba cha polyurethane ndi chinthu chabwino kwambiri chotchinjiriza matenthedwe, chokhala ndi zida zabwino zamakina, kutsika kwamafuta otsika ndi maubwino ena, kotero chimagwiritsidwa ntchito kwambiri pantchito yomanga nyumba.
Wotulutsa thovu ndi chimodzi mwazowonjezera zazikulu pakupanga thovu lolimba la polyurethane. Malinga ndi kachitidwe kake kachitidwe, imatha kugawidwa m'magulu awiri: mankhwala otulutsa thovu ndi otulutsa thovu.
Gulu la othandizira thovu
Mankhwala opangidwa ndi thovu ndi chowonjezera chomwe chimapanga mpweya ndi thovu za polyurethane panthawi yomwe isocyanates ndi polyols zimachita. Madzi ndi oyimira chithovu cha mankhwala, chomwe chimagwirizana ndi gawo la isocyanate kupanga mpweya wa carbon dioxide, kuti apange thovu la polyurethane. Thupi lotulutsa thovu ndi chowonjezera chomwe chimawonjezeredwa popanga chithovu cholimba cha polyurethane, chomwe chimatulutsa thovu la polyurethane kudzera mumagetsi. Mankhwala opangidwa ndi thovu ndi zinthu zomwe zimawotcha pang'ono, monga hydrofluorocarbons (HFC) kapena alkane (HC).
Ndondomeko ya chitukuko chawothandizira thovuidayamba chakumapeto kwa zaka za m'ma 1950, kampani ya DuPont idagwiritsa ntchito trichloro-fluoromethane (CFC-11) ngati wothandizira thovu lolimba la polyurethane, ndipo idachita bwino kwambiri, kuyambira pamenepo CFC-11 yakhala ikugwiritsidwa ntchito kwambiri pantchito ya thovu lolimba la polyurethane. Pamene CFC-11 inatsimikizira kuwononga ozoni wosanjikiza, mayiko a Kumadzulo kwa Ulaya anasiya kugwiritsa ntchito CFC-11 kumapeto kwa 1994, ndipo China inaletsanso kupanga ndi kugwiritsa ntchito CFC-11 mu 2007. Pambuyo pake, United States ndi Ulaya analetsa kugwiritsa ntchito CFC-11. ya CFC-11 m'malo mwa HCFC-141b mu 2003 ndi 2004, motsatana. Pamene chidziwitso cha chilengedwe chikuwonjezeka, maiko akuyamba kupanga ndi kugwiritsa ntchito njira zina zomwe zili ndi mphamvu zochepa za kutentha kwa dziko (GWP).
Othandizira thovu amtundu wa Hfc adalowa m'malo mwa CFC-11 ndi HCFC-141b, koma mtengo wa GWP wamitundu yamtundu wa HFC ukadali wokwera, zomwe sizothandiza kuteteza chilengedwe. Chifukwa chake, m'zaka zaposachedwa, kuyang'ana kwachitukuko kwa othandizira thovu pantchito yomanga kwasintha m'malo otsika a GWP.
Ubwino ndi kuipa kwa wothandizira thovu
Monga mtundu wazinthu zotchinjiriza, thovu lolimba la polyurethane lili ndi zabwino zambiri, monga magwiridwe antchito abwino kwambiri amafuta, mphamvu zamakina abwino, mayamwidwe abwino amawu, moyo wokhazikika wanthawi yayitali ndi zina zotero.
Monga wothandizira wofunikira pokonzekera thovu lolimba la polyurethane, wotulutsa thovu amakhudza kwambiri magwiridwe antchito, mtengo komanso chitetezo cha chilengedwe cha zida zotenthetsera. Ubwino wa mankhwala thovu wothandizila mofulumira thobvu liwiro, yunifolomu thobvu, angagwiritsidwe ntchito osiyanasiyana kutentha ndi chinyezi, angapeze mkulu thobvu mlingo, kuti akonze mkulu-ntchito polyurethane okhwima thovu.
Komabe, mankhwala a thovu amatha kutulutsa mpweya woipa, monga carbon dioxide, carbon monoxide ndi nitrogen oxides, zomwe zimawononga chilengedwe. Ubwino wogwiritsa ntchito thovu ndikuti sichitulutsa mpweya woyipa, sichimakhudza chilengedwe, ndipo imathanso kupeza kukula kwakung'ono kwa thovu komanso ntchito yabwino yotchinjiriza. Komabe, opanga thovu amakhala ndi kutulutsa thovu pang'onopang'ono ndipo amafuna kutentha ndi chinyezi kuti azichita bwino kwambiri.
Monga mtundu wazinthu zotchinjiriza, thovu lolimba la polyurethane lili ndi zabwino zambiri, monga magwiridwe antchito abwino kwambiri amafuta, mphamvu zamakina abwino, mayamwidwe abwino amawu, moyo wokhazikika wanthawi yayitali ndi zina zotero.
Monga wothandizira wofunikira pokonzekerathovu lolimba la polyurethane, wotulutsa thovu amakhudza kwambiri magwiridwe antchito, mtengo komanso chitetezo cha chilengedwe cha zida zotchinjiriza matenthedwe. Ubwino wa mankhwala thovu wothandizila mofulumira thobvu liwiro, yunifolomu thobvu, angagwiritsidwe ntchito osiyanasiyana kutentha ndi chinyezi, angapeze mkulu thobvu mlingo, kuti akonze mkulu-ntchito polyurethane okhwima thovu.
Komabe, mankhwala a thovu amatha kutulutsa mpweya woipa, monga carbon dioxide, carbon monoxide ndi nitrogen oxides, zomwe zimawononga chilengedwe. Ubwino wogwiritsa ntchito thovu ndikuti sichitulutsa mpweya woyipa, sichimakhudza chilengedwe, ndipo imathanso kupeza kukula kwakung'ono kwa thovu komanso ntchito yabwino yotchinjiriza. Komabe, opanga thovu amakhala ndi kutulutsa thovu pang'onopang'ono ndipo amafuna kutentha ndi chinyezi kuti azichita bwino kwambiri.
Chitukuko chamtsogolo
Kachitidwe ka ntchito zopanga thovu pantchito yomanga yamtsogolo makamaka pakupanga malo otsika a GWP. Mwachitsanzo, CO2, HFO, ndi njira zina zamadzi, zomwe zili ndi GWP yochepa, ziro ODP, ndi zina zachilengedwe, zakhala zikugwiritsidwa ntchito kwambiri popanga thovu lolimba la polyurethane. Kuphatikiza apo, tekinoloje yotchinjiriza zomangira ikupitilira kukula, wopangira thovu apanganso magwiridwe antchito abwino kwambiri, monga kutsekemera kwabwinoko, kuchuluka kwa thovu, komanso kukula kochepa kwa kuwira.
M'zaka zaposachedwa, mabizinesi am'nyumba ndi akunja a organofluorine akhala akufufuza mwachangu ndikupanga zida zatsopano zotulutsa thovu zokhala ndi fluorine, kuphatikiza fluorinated olefins (HFO) foaming agents, zomwe zimatchedwa m'badwo wachinayi wa foaming agents ndipo ndi wothandizira thovu wokhala ndi mpweya wabwino. gawo matenthedwe madutsidwe ndi ubwino chilengedwe.
Nthawi yotumiza: Jun-21-2024