Ukwethulwa kwe-ejenti enegwebu yegwebu eliqinile le-polyurethane elisetshenziswa emkhakheni wokwakha
Ngezidingo ezikhulayo zezakhiwo zesimanje zokonga amandla kanye nokuvikelwa kwemvelo, ukusebenza kokushisa okushisayo kwezinto zokwakha kuya ngokuya kubaluleke kakhulu. Phakathi kwazo, i-polyurethane i-foam eqinile iyinto enhle kakhulu yokushisa okushisayo, enezici ezinhle zemishini, ukuqhutshwa kokushisa okuphansi nezinye izinzuzo, ngakho-ke isetshenziswa kabanzi emkhakheni wokwakhiwa kwe-insulation.
I-ejenti enegwebu ingenye yezithako eziyinhloko ekukhiqizeni igwebu eliqinile le-polyurethane. Ngokusho kwendlela yayo yokusebenza, ingahlukaniswa izigaba ezimbili: i-ejenti ekhihliza amagwebu yamakhemikhali kanye ne-ejenti eyenza amagwebu.
Ukuhlukaniswa kwama-foam agents
Ikhemikhali i-foam agent iyisengezo esikhiqiza igesi kanye namagwebu ezinto ze-polyurethane ngesikhathi sokusabela kwe-isocyanates nama-polyols. Amanzi amele i-ejenti yegwebu lekhemikhali, ehlangana nengxenye ye-isocyanate yakhe igesi ye-carbon dioxide, ukuze igwebu i-polyurethane material. I-ejenti eyenza amagwebu engokoqobo iyisengezo esingeziwe ekukhiqizeni igwebu eliqinile le-polyurethane, elifaka amagwebu ezinto ze-polyurethane ngokusebenzisa isenzo somzimba segesi. Ama-ejenti wegwebu aphathekayo ikakhulukazi amakhompawundi ezinto eziphilayo abilisa kancane, njengama-hydrofluorocarbons (HFC) noma izinhlanganisela ze-alkane (HC).
Inqubo yokuthuthukiswa kwei-ejenti yegwebuyaqala ngasekupheleni kwawo-1950s, inkampani yakwaDuPont yasebenzisa i-trichloro-fluoromethane (CFC-11) njenge-ejenti ecwebezelayo yegwebu le-polyurethane, futhi yathola ukusebenza okungcono komkhiqizo, kusukela ngaleso sikhathi i-CFC-11 ibisetshenziswa kabanzi emkhakheni wegwebu eliqinile le-polyurethane. Njengoba i-CFC-11 yabonakala ilimaza ungqimba lwe-ozone, amazwe aseNtshonalanga Yurophu ayeka ukusebenzisa i-CFC-11 ekupheleni kuka-1994, futhi iChina yaphinde yavala ukukhiqizwa nokusetshenziswa kwe-CFC-11 ngo-2007. ye-CFC-11 esikhundleni se-HCFC-141b ngo-2003 nango-2004, ngokulandelana. Njengoba ukwanda kokuqwashisa ngemvelo, amazwe aqala ukuthuthukisa nokusebenzisa ezinye izindlela ezinamandla aphansi okufudumala komhlaba (GWP).
Ama-ejenti egwebu ohlobo lwe-Hfc ake athatha indawo ye-CFC-11 ne-HCFC-141b, kodwa inani le-GWP lenhlanganisela yohlobo lwe-HFC lisephezulu uma kuqhathaniswa, elingahambisani nokuvikelwa kwemvelo. Ngakho-ke, eminyakeni yamuva nje, ukugxila kokuthuthukiswa kwama-agent we-foam emkhakheni wezokwakha kushintshele kwezinye izindlela eziphansi ze-GWP.
Izinzuzo nezingozi ze-foam agents
Njengohlobo lwezinto zokufakelwa, igwebu eliqinile le-polyurethane linezinzuzo eziningi, njengokusebenza okuhle kakhulu kokufakwa kwe-thermal, amandla amahle emishini, ukusebenza kahle kokumuncwa komsindo, impilo yesevisi ezinzile yesikhathi eside nokunye.
Njengomsizi obalulekile ekulungiseleleni igwebu eliqinile le-polyurethane, i-ejenti enegwebu inomthelela obalulekile ekusebenzeni, izindleko kanye nokuvikelwa kwemvelo kwezinto zokushisa ezishisayo. Izinzuzo ze-agent ye-foaming yamakhemikhali isivinini esinegwebu elisheshayo, i-foaming efanayo, ingasetshenziswa ezinhlobonhlobo zamazinga okushisa nomswakama, ingathola izinga eliphezulu lokugwebu, ukuze kulungiswe igwebu eliqinile le-polyurethane elisebenza kahle.
Kodwa-ke, ama-foam agents amakhemikhali angakhiqiza amagesi ayingozi, njenge-carbon dioxide, i-carbon monoxide nama-nitrogen oxides, okubangela ukungcoliswa kwemvelo. Inzuzo ye-ejenti yegwebu elibonakalayo ukuthi ayikhiqizi amagesi ayingozi, inomthelela omncane emvelweni, futhi ingathola nosayizi omncane webhamuza nokusebenza okungcono kokufakwa. Kodwa-ke, ama-ejenti egwebu angokoqobo anezinga lokukhihliza amagwebu elihamba kancane futhi adinga izinga lokushisa eliphakeme nomswakama ukuze enze okusemandleni awo.
Njengohlobo lwezinto zokufakelwa, igwebu eliqinile le-polyurethane linezinzuzo eziningi, njengokusebenza okuhle kakhulu kokufakwa kwe-thermal, amandla amahle emishini, ukusebenza kahle kokumuncwa komsindo, impilo yesevisi ezinzile yesikhathi eside nokunye.
Njengomsizi obalulekile ekulungiselelenii-polyurethane foam eqinile, i-ejenti enegwebu inomthelela obalulekile ekusebenzeni, izindleko kanye nokuvikelwa kwemvelo kwezinto zokushisa ezishisayo. Izinzuzo ze-agent ye-foaming yamakhemikhali isivinini esinegwebu elisheshayo, i-foaming efanayo, ingasetshenziswa ezinhlobonhlobo zamazinga okushisa nomswakama, ingathola izinga eliphezulu lokugwebu, ukuze kulungiswe igwebu eliqinile le-polyurethane elisebenza kahle.
Kodwa-ke, ama-foam agents amakhemikhali angakhiqiza amagesi ayingozi, njenge-carbon dioxide, i-carbon monoxide nama-nitrogen oxides, okubangela ukungcoliswa kwemvelo. Inzuzo ye-ejenti yegwebu elibonakalayo ukuthi ayikhiqizi amagesi ayingozi, inomthelela omncane emvelweni, futhi ingathola nosayizi omncane webhamuza nokusebenza okungcono kokufakwa. Kodwa-ke, ama-ejenti egwebu angokoqobo anezinga lokukhihliza amagwebu elihamba kancane futhi adinga izinga lokushisa eliphakeme nomswakama ukuze enze okusemandleni awo.
Umkhuba wentuthuko yesikhathi esizayo
Umkhuba wama-ejenti akhipha amagwebu embonini yezokwakha yesikhathi esizayo ikakhulukazi ubheke ekuthuthukisweni kwezindawo eziphansi ze-GWP. Isibonelo, i-CO2, i-HFO, nezinye izindlela zamanzi, ezine-GWP ephansi, i-ODP eyiziro, nokunye ukusebenza kwemvelo, kusetshenziswe kabanzi ekukhiqizeni igwebu eliqinile le-polyurethane. Ngaphezu kwalokho, njengoba ubuchwepheshe bezinto zokufaka izinto zokwakha buqhubeka buthuthuka, i-ejenti ekhihliza amagwebu izothuthukisa ukusebenza okuhle kakhulu, njengokusebenza okungcono kokufakwa kwe-insulation, izinga eliphezulu lokukhihliza amagwebu, nosayizi webhamuza elincane.
Eminyakeni yakamuva, amabhizinisi amakhemikhali e-organofluorine asekhaya nakwamanye amazwe abelokhu efuna futhi ethuthukisa ama-agent amasha aqukethe amagwebu aqukethe i-fluorine, okuhlanganisa ama-fluorinated olefins (HFO) ama-foaming agents, abizwa ngokuthi ama-foaming agents esizukulwane sesine futhi ayi-ejenti eyenza amagwebu ngokomzimba negesi enhle. isigaba se-thermal conductivity kanye nezinzuzo zemvelo.
Isikhathi sokuthumela: Jun-21-2024