Rock wool sandwich panels feature a "sandwich" structure composed of metal facing sheets, a rock wool core, and a high-strength adhesive. The metal facings provide structural load-bearing capacity (resisting bending and compression) as well as external protection; the rock wool core serves to provide thermal insulation, fire resistance, and sound absorption/insulation; and the adhesive ensures the overall structural integrity. The rock wool core is manufactured primarily from natural minerals, such as basalt, which are melted at high temperatures and spun into fibers, then bonded and cured using an adhesive.
Rock wool sandwich panels offer excellent fire resistance and are classified as Class A non-combustible materials. Testing indicates they can withstand temperatures exceeding 1000°C; a 50mm-thick panel, for instance, has a fire resistance rating of REI30. When exposed to an open flame, only the surface of the rock wool shows signs of charring, and combustion ceases immediately upon removal of the heat source. If a lit cigarette butt is placed on the material, the rock wool merely smolders, with minimal lasting damage once the object is removed. Consequently, these panels exhibit significant flame-retardant properties, effectively curbing the spread of fire during an incident.
Rock wool sandwich panels also provide superior thermal insulation, with performance calculated based on the thermal conductivity of the rock wool (λ = 0.043 W/m·K). As a porous fibrous material, the rock wool core contains internal voids that form pockets of still air, which effectively inhibit heat transfer.