What are the grades of refractory exterior wall thermal insulation materials?
Classification of fire rating of extrior thermal insulation materials 1, According to national standard GB8624-97, the combustion performance of building materials are divided into the following grades A level: Incombustible building materials: Materials hardly burn. B1 class: Flame-retardant building materials: Flame-retardant material has good flame resistance. In case of fire in the air or at high temperature, it is difficult to catch fire and the fire will not spread quickly. And when the combustion source is removed, the burning will stop immediately. B2 Class: Combustible building materials: Combustible materials have a certain flame retardancy. In case of fire in the air or at high temperature, it will immediately burst into flames and it is easily to spread fire, such as wooden column, wooden roof truss, wooden beams and wooden stairs, etc. B3 level: Inflammable building materials: It has no flame retardant effect, and it is extremely inflammable, and the risk of fire is high. Classification of exterior wall thermal insulation materials according to fire rating: 1. Thermal insulation materials with A-level combustion performance Rock wool, glass wool, foam glass, foamed ceramic, foam cement, hole-closed perlite, etc. 2, Thermal insulation materials with B1-level combustion performance: Extruded polystyrene board (XPS) after special treatment / polyurethane (PU) after special treatment, phenolic aldehyde, gelatine powder polystyrene granule, and etc. 3. Thermal insulation materials with B2-level combustion performance: Molded polystyrene board (EPS), extruded polystyrene board (XPS), polyurethane (PU), polyethylene (PE), etc.