Rock wool core is inorganic non combustible material reaching A fire rating the highest grade in building insulation materials. Under continuous high temperature flame it maintains structural integrity without molten dripping or flammable gas release. Panel surface steel plate forms sealed isolation layer to stop fire cross spread between building zones. This performance makes rock wool the mandatory panel core for paint workshops chemical factories and high standard medical cleanrooms.
PU and PIR both own ultra low thermal conductivity superior to rock wool and EPS for low temperature constant temperature buildings. Ordinary PU foam melts easily under long term high temperature while upgraded PIR forms carbonized protective layer to slow flame spread. PIR panel smoke density during combustion is far lower than PU to reduce personnel evacuation hazards. Cold storage and food constant temperature workshops mostly select PIR for long term energy saving and safety balance.
EPS foam core has the lightest unit weight among four materials to cut transportation and hoisting cost largely. Raw material production process lowers finished panel selling price suitable temporary construction simple warehouse low budget auxiliary buildings. Its fire resistance performance is the weakest only reaching B2 grade even with flame retardant additives so cannot be used high fire risk industrial production main body structure.
Rock wool fits high fire risk factory and medical cleanroom; PIR matches cold room food constant temperature cleanroom; EPS adapts temporary workshop simple storage shed; PU applies ordinary low temperature warehouse with medium fire requirement. Mixed matching mode can cut total project investment for large comprehensive industrial parks such as rock wool wall plus PIR roof to balance safety and energy saving effect simultaneously.