Main hom raw khoom:
1. Hydrocarbons
n-pentane, isopentane, cyclopentane: Cov no yog cov feem ntau siv tshuab tshuab hauv polystyrene (EPS) thiab nruj polyurethane (PU) foams. Qhov zoo muaj xws li tus nqi qis thiab kev ua haujlwm zoo foaming; qhov tsis zoo yog flammability.
2. Halogenated hydrocarbons (muaj chlorine / fluorine)
Hydrochlorofluorocarbons (HCFCs): Piv txwv li, HCFC-141b. Vim lawv lub peev xwm ozone-depleting, lawv raug phased tawm.
Hydrofluorocarbons (HFCs): Piv txwv li, HFC-134a, HFC-245fa. Lawv muaj pes tsawg ozone depletion muaj peev xwm, tab sis muaj peev xwm ua rau lub ntiaj teb sov siab, thiab lawv cov kev siv kuj raug txwv.
Hydrofluoroolefins (HFOs): Piv txwv li, HFO-1234ze, HFO-1336mzz. Cov no yog cov tiam tshiab ntawm ib puag ncig tus phooj ywg tshuab tshuab nrog xoom ozone depletion muaj peev xwm thiab tsis tshua muaj lub ntiaj teb ua kom sov muaj peev xwm, thiab tam sim no yog thaj chaw tseem ceeb ntawm kev txhim kho.
3. Inert gases
Cov pa roj carbon dioxide (CO₂): Siv dav hauv cov ntaub ntawv hloov pauv polyurethane, feem ntau yog tsim los ntawm cov tshuaj tiv thaiv dej nrog isocyanate, lossis los ntawm kev txhaj tshuaj CO₂ ncaj qha. Ib puag ncig tus phooj ywg, tsis yog - lom, thiab tus nqi qis.
Nitrogen (N₂): Feem ntau siv hauv compression molding foaming ntawm cov ntaub ntawv xws li roj hmab thiab EVA, ib puag ncig tus phooj ywg thiab nyab xeeb.
4. Lwm tus
Dej: Hauv polyurethane foams, dej yog ib qho tseem ceeb ntawm cov tshuaj tshuab tshuab (tsim CO₂ los ntawm cov tshuaj tiv thaiv nrog isocyanate), tab sis los ntawm kev xav ntawm lub cev, nws kuj yog ib qho ntawm cov khoom siv roj.
