Ukutyheli kwesiponji sogwebu lwepolyurethane kube yingxaki edide abavelisi besiponji kunye nabavelisi bepolyol ixesha elide.
Abaninzi abavelisi besiponji, ngokukodwa abavelisi be-sponge bezinga eliphezulu, bazama ukuphucula ukusebenza kwe-sponge-yellowing ngokudibanisa i-antioxidants kunye ne-stabilizers yokukhanya, kodwa umphumo awubalulekanga.
UCiba Jinghua, njengomthengisi owaziwayo kwihlabathi lezongezo ezichasene nokwaluphala, uye waphuhlisa uthotho lwe-IRGASTAB ye-antioxidants, ngakumbi ukuveliswa kwayo kwe-IRGASTAB PUR 68, ebonelela ngokusisiseko iseti yezisombululo zesiponji tyheli. Eli phepha liza kuhlalutya ngokucwangcisiweyo izizathu ze-sponge yellowing ngokusekelwe kwiimpawu ze-polyol kunye nemveliso yesiponji phezulu nasezantsi, kwaye uchaze izisombululo ezihambelanayo.
Ngokubanzi, ngokwembono yezongezo, ukutyheli kwezipontshi kubandakanya ezi ntlobo zine zilandelayo:-i-yellowing ye-oksijini eshushu eguga okubangelwa ubushushu obuphezulu ngexesha lesiponji ligwebu / ukusetyenzwa.
Ukufuthwa kwerhasi okubangelwa kukuchaphazeleka kwinitrogen oxides emoyeni (NOx).
Ungcoliseko lwelaphu olubangelwa sisipontshi.
Umthubi obangelwa kukuvezwa kwesipontshi kwimitha ye-ultraviolet.
Ezi zityheli zihlala zihambelana ngqo ne-antioxidants.
Ngamanye amazwi, ubukho be-antioxidants bunokuba nefuthe elihle lokuthintela kokunye kokutyheli kungasentla, umzekelo, ukutyheli kokuguga kweoksijini eshushu okubangelwa kubushushu obuphezulu ngexesha lesiponji sigwebukile / ukusetyenzwa kuthintelwe kukongezwa kwe-antioxidants.
Nangona kunjalo, inokuthi idlale indima engalunganga kwaye ikhuthaze ukwenzeka kwezinye iintlobo ze-yellowing, umzekelo, i-amine antioxidants inokukhuthaza i-sponge yellowing xa ibonakaliswe kwi-nitrogen oxides emoyeni (NOx, ngokukodwa kwi-exhaust yemoto), okanye imisebe ye-ultraviolet, ngelixa. I-antioxidant BHT ngoyena nobangela wokungcoliseka kwelaphu.
Ngokuqhelekileyo, abavelisi be-polyol baya kongeza inani elithile le-antioxidants kwi-polyols ukuze baqinisekise ukuveliswa okukhuselekileyo kwabavelisi be-foaming esezantsi kwinkqubo yogwebu lwe-polyols.
Okwangoku, iintlobo eziphambili ze-antioxidants ezisetyenziswa ngabavelisi be-polyether basekhaya yi-BHT kunye ne-amine antioxidants okanye i-phenothiocyanate compound antioxidants, ngelixa abavelisi be-polyether abaziwayo bezizwe ngezizwe bakhetha ubukhulu be-molecular ubunzima obuthintele i-phenolic antioxidants, njenge-Ciba's IRGANOX 1135 (ubunzima obuphezulu bemolekyuli buthintelwe. i-phenolic antioxidants) kunye ne-IRGANOX 5057 (i-amine antioxidants).
Njengomenzi wemarike yesipontshi, xa ufumana i-polyol, ngaphandle kokhuseleko, iindleko kunye nokusebenza kwegwebu, kunqabile ukuvavanya umphumo wenkqubo ye-antioxidant kwi-polyol kwi-sponge yellowing.
Nangona kunjalo, le nto, ehlala ihoywa, ifihla izizathu ezibalulekileyo ezichaphazela i-yellowing yesiponji.
Ngokuqhelekileyo kwimeko efanelekileyo, i-antioxidant ekhoyo kwi-polyol inokuthintela ukuguga kunye nokuthotywa kwe-polymer okubangelwa ubushushu obuphezulu obuveliswa yi-foam ngokwayo, eqinisekisa ukuveliswa okukhuselekileyo kwenkqubo ye-sponge foaming. kwakhona ngempumelelo ukuthintela core yellowing kwinkqubo isiponji amagwebu.
Nangona kunjalo, ngokugqitywa kwesiponji sigwebu, i-antioxidants eshiywe kwisiponji kulula ukubangela ukuba izipontshi ezininzi zibe tyheli.
