Ukwakheka kweekhemikhali zolwelo ezimbini -zecandelo lezinto ezigwebu ugwebu zidla ngokuqulunqwa licandelo A (icandelo le-isocyanate) kunye necandelo B (icandelo lepolyol). Emva kokuxuba, amacandelo amabini asabela ukuvelisa i-foam. Oku kulandelayo luhlalutyo oluthile:
1. Icandelo A (icandelo le-isocyanate)
• Amacandelo aphambili: i-polyisocyanates, eyona ixhaphakileyo yi-toluene diisocyanate (TDI) kunye ne-diphenylmethane diisocyanate (MDI), ngaphezu kwe-polymeric MDI (PAPI).
• Umsebenzi: "Njenge-agent edibanisayo" yokusabela, idibana neqela le-hydrogen esebenzayo kwicandelo B kwaye iyimathiriyeli ekrwada engundoqo yokwenza ulwakhiwo logwebu.
2.Icandelo B (ilungu lepolyol)
Iqulethe amacandelo ahlukeneyo athatha inxaxheba ekuphenduleni kunye nokulawula iimpawu ze-foam:
• Iipolyols: ezifana nepolyether polyol kunye nepolyester polyol, ezibonelela ngehydroxyl (-OH) kwaye zisabele nge-iqela le-NCO le-isocyanate, zenza isiseko se-foam skeleton.
• I-ejenti yogwebu: ivelisa igesi ukwandisa umxube kwaye yenze amaqamza. Ezona zixhaphakileyo zii-agent ezikhupha ugwebu (umzekelo, ii-Freon substitutes, i-cyclopentane) kunye neekhemikhali ezikhupha ugwebu (umzekelo, amanzi, athi adibane ne-isocyanate avelise i-carbon dioxide).
• I-Catalyst: Ikhawuleza ukusabela, njenge-amine catalyst (ikhuthaza ukusabela kogwebu) kunye ne-organotin catalyst (ikhuthaza ukusabela kwejeli).
• Ii-surfactants: zizinzisa ubume be-foam kwaye uthintele ukugqabhuka kwe-foam. Ngokuqhelekileyo zikhompawundi ze-siloxane.
• Ezinye izongezo: ezifana ne-flame retardants, fillers, colorants, njl., ezongezwa ngokweemfuno zesicelo sokuphucula i-flame retardant, amandla kunye nezinye iimpawu ze-foam.
3.Umgaqo-siseko wokusabela
Xa amacandelo A kunye no-B exutywe,-amaqela e-NCO e-isocyanate asabela kunye -namaqela e-OH eepolyols kunye namanzi, ekhupha igesi (i-foaming) ukwenza i-foam material ene-porous. Imilinganiselo ethile kunye neentlobo zamacandelo zimisela ubuninzi be-foam, ukuqina, iimpawu zokugquma kwe-thermal, kunye nezinye iimpawu. Esi sixhobo sisebenza ngeendlela ezininzi sifumana usetyenziso olubanzi kwiinkqubo zokugquma, izisombululo zokupakisha, ukwenziwa kwefenitshala, kunye namashishini anxulumeneyo.