U.S. Gypsum developed a method of dispersing cellulose fiber throughout gypsum panels, producing homogeneous, paperless panels at its Gypsum, Ohio, plant. These Fiberock panels have a higher density and are more durable than conventional gypsum board. However, these new gypsum panels do not comply with existing building code noncombustibility requirements. Although we carry a great deal of in-house fire testing expertise, it became apparent that we needed to go beyond this to expedite obtaining building code evaluation reports for equivalency of Fiberock to conventional gypsum board. This is a small, spherical steel container that resembles the cartoon version of a bomb.
Fuel is applied to the sample before it is ignited, and an oxygen feed promotes combustion.
Researchers monitor the heat released from the burning sample by measuring the temperature increase of the water in a bath containing the bomb. This reveals how many Btu are potentially released per pound of material exposed to a fire. Extensive cone calorimeter testing was used to further determine the Btu heat release, and tunnel testing was used to determine the surface burning characteristics of the Fiberock panels. Tunnel testing involves mounting a specimen on the ceiling of a tunnel-like apparatus, and igniting one end of the sample. The progression of flame down the tunnel is monitored, as is the smoke that is generated.