Ukwaziswa kwearhente yokwenza amagwebu kwi-polyurethane eqinileyo foam esetyenziswa kwintsimi yokwakha
Ngenxa yokwanda kweemfuno zezakhiwo zanamhlanje zokonga amandla kunye nokukhuselwa kokusingqongileyo, ukusebenza kwe-thermal insulation yezixhobo zokwakha kuya kuba yinto ebaluleke ngakumbi. Phakathi kwazo, i-polyurethane rigid foam sisixhobo esihle kakhulu se-thermal insulation, esineempawu ezilungileyo zoomatshini, i-thermal conductivity ephantsi kunye nezinye izibonelelo, ngoko ke isetyenziswa kakhulu kwicandelo le-insulation yezakhiwo.
I-agent ekhupha igwebu yenye yezona zinto ziphambili ezisetyenziswayo ekuveliseni igwebu eliqinileyo le-polyurethane. Ngokwendlela esebenza ngayo, inokwahlulwahlulwa ibe ziindidi ezimbini: i-agent ekhupha igwebu ngeekhemikhali kunye ne-arhente ekhupha igwebu ngokwasemzimbeni.
Ukwahlulwahlulwa kweearhente zefoam
I-arhente ye-foam yekhemikhali sisongezelelo esivelisa igesi kunye nezinto ze-polyurethane ezikhupha amagwebu ngexesha lokusabela kwe-isocyanates kunye ne-polyols. Amanzi amele i-arhente ye-foam yekhemikhali, ephendula kunye nenxalenye ye-isocyanate ukwenza igesi ye-carbon dioxide, ukuze ikhuphe igwebu kwi-polyurethane. I-arhente ye-foam ebonakalayo sisongezelelo esongezwayo kwinkqubo yokuvelisa i-polyurethane hard foam, ekhupha igwebu kwi-polyurethane ngesenzo somzimba segesi. Ii-arhente ze-foam ezibonakalayo ikakhulu ziikhompawundi ze-organic ezibila kancinci, ezifana nee-hydrofluorocarbons (HFC) okanye iikhompawundi ze-alkane (HC).
Inkqubo yophuhliso lweiarhente yegwebuYaqala ngasekupheleni kweminyaka yoo-1950, inkampani iDuPont yasebenzisa i-trichloro-fluoromethane (CFC-11) njenge-arhente yokufutha i-polyurethane hard foam, yaza yafumana ukusebenza okungcono kwemveliso, ukusukela ngoko i-CFC-11 isetyenziswa kakhulu kwicandelo le-polyurethane hard foam. Njengoko i-CFC-11 yabonakalisa ukuba yonakalisa umaleko we-ozone, amazwe aseNtshona Yurophu ayeka ukusebenzisa i-CFC-11 ekupheleni kuka-1994, kwaye iChina nayo yavala ukuveliswa nokusetyenziswa kwe-CFC-11 ngo-2007. Emva koko, i-United States neYurophu zavala ukusetyenziswa kwe-CFC-11 HCFC-141b endaweni yayo ngo-2003 nango-2004, ngokulandelelana. Njengoko ulwazi ngokusingqongileyo lusanda, amazwe aqala ukuphuhlisa nokusebenzisa ezinye iindlela ezinomlinganiselo ophantsi wokufudumala kwehlabathi (GWP).
Iiarhente zefoam zohlobo lwe-Hfc zazikade zithatha indawo ye-CFC-11 kunye ne-HCFC-141b, kodwa ixabiso le-GWP leekhompawundi zohlobo lwe-HFC lisaphezulu, nto leyo engalungelanga ukukhuselwa kwendalo. Ke ngoko, kwiminyaka yakutshanje, ingqwalasela yophuhliso lweearhente zefoam kwicandelo lokwakha itshintshele kwezinye iindlela ze-GWP ephantsi.
Iingenelo kunye neengxaki zeearhente zefoam
Njengohlobo lwezinto zokwambathisa, i-polyurethane rigid foam ineengenelo ezininzi, ezifana nokusebenza kakuhle kwe-thermal insulation, amandla amahle oomatshini, ukusebenza kakuhle kokufunxa isandi, ubomi benkonzo ezinzileyo ixesha elide, njl.
Njengesixhobo esibalulekileyo sokuncedisa ekulungiseleleni i-polyurethane hard foam, i-foam agent inempembelelo ebalulekileyo ekusebenzeni, kwiindleko kunye nokukhuselwa kwendalo kwezinto zokukhusela ubushushu. Iingenelo ze-chemical foam agent zisantya esikhawulezayo sokufutha, ukufutha okufanayo, ingasetyenziswa kumanqanaba obushushu amaninzi kunye nokufuma, inokufumana izinga eliphezulu lokufutha, ukuze kulungiselelwe i-polyurethane rigid foam esebenza kakuhle.
Nangona kunjalo, ii-agents ze-foam zamakhemikhali zinokuvelisa iigesi ezinobungozi, ezifana ne-carbon dioxide, i-carbon monoxide kunye ne-nitrogen oxides, nto leyo ebangela ungcoliseko kwindalo esingqongileyo. Inzuzo ye-agent ye-foam ebonakalayo kukuba ayivelisi iigesi ezinobungozi, ayinampembelelo ingako kwindalo esingqongileyo, kwaye inokufumana ubungakanani obuncinci bamaqamza kunye nokusebenza ngcono kobushushu. Nangona kunjalo, ii-agents ze-foam ezibonakalayo zinesantya esicothayo sokufutha kwaye zifuna ubushushu obuphezulu kunye nokufuma ukuze zisebenze kakuhle.
Njengohlobo lwezinto zokwambathisa, i-polyurethane rigid foam ineengenelo ezininzi, ezifana nokusebenza kakuhle kwe-thermal insulation, amandla amahle oomatshini, ukusebenza kakuhle kokufunxa isandi, ubomi benkonzo ezinzileyo ixesha elide, njl.
Njengomncedisi obalulekileyo ekulungiselelenii-polyurethane eqinileyo, i-arhente yokufutha inempembelelo ebalulekileyo ekusebenzeni, kwiindleko kunye nokukhuselwa kwendalo kwezinto zokugquma ubushushu. Iingenelo ze-arhente yokufutha iikhemikhali zisantya sokufutha esikhawulezayo, ukufutha okufanayo, ingasetyenziswa kumanqanaba amaninzi obushushu kunye nokufuma, inokufumana izinga eliphezulu lokufutha, ukuze kulungiselelwe i-polyurethane rigid foam esebenza kakuhle.
Nangona kunjalo, ii-agents ze-foam zamakhemikhali zinokuvelisa iigesi ezinobungozi, ezifana ne-carbon dioxide, i-carbon monoxide kunye ne-nitrogen oxides, nto leyo ebangela ungcoliseko kwindalo esingqongileyo. Inzuzo ye-agent ye-foam ebonakalayo kukuba ayivelisi iigesi ezinobungozi, ayinampembelelo ingako kwindalo esingqongileyo, kwaye inokufumana ubungakanani obuncinci bamaqamza kunye nokusebenza ngcono kobushushu. Nangona kunjalo, ii-agents ze-foam ezibonakalayo zinesantya esicothayo sokufutha kwaye zifuna ubushushu obuphezulu kunye nokufuma ukuze zisebenze kakuhle.
Imeko yophuhliso lwexesha elizayo
Umkhwa weearhente ezikhupha amagwebu kwishishini lokwakha elizayo ujolise kakhulu ekuphuhlisweni kwezinto ezithatha indawo ye-GWP ephantsi. Umzekelo, ii-CO2, i-HFO, kunye nezinye iindlela zamanzi, ezine-GWP ephantsi, i-ODP engekhoyo, kunye nezinye iindlela zokusebenza kokusingqongileyo, zisetyenziswe kakhulu ekuveliseni i-polyurethane rigid foam. Ukongeza, njengoko iteknoloji yezinto zokugquma izakhiwo iqhubeka nophuhliso, iarhente ekhupha amagwebu iya kuphuhlisa ukusebenza okugqwesileyo ngakumbi, okufana nokusebenza ngcono kokugquma, izinga eliphezulu lokugquma amagwebu, kunye nobukhulu obuncinci bamaqamza.
Kwiminyaka yakutshanje, amashishini eekhemikhali ze-organofluorine zasekhaya nezangaphandle ebesoloko ekhangela kwaye ephuhlisa ii-arhente ezintsha ze-fluorine-physical foaming agents, kuquka ii-fluorinated olefins (HFO) foaming agents, ezibizwa ngokuba zii-foaming agents zesizukulwana sesine kwaye ziyi-arhente ye-physical foaming ene-gas phase thermal conductivity elungileyo kunye neenzuzo zokusingqongileyo.
Ixesha leposi: Juni-21-2024