In chemistry, sublimation is a process which is known to use massive amounts of BTU energy in effecting a transormation of a solid material directly into vaporizing gases without an intermediate liquefying stage (i.e.: dry ice). Thermo-Lag technology utilizes this process.Thermo-Lag sublimes like dry ice, but at higher temperatures, maintaining the temperature of the substrate at the temperature of sublimation during the chemical reaction and creating a counterflow of gases to block the heat input of fire. The fire reating provided by a Thermo-Lag coating is largely determined by the applied thickness. Thermo-Lag provides more fire protection than any other fireproofing at a comparable thickness!
As the sublimation continues, a protective char layer begins to form between the high hear and the flame source and the structural steel coated with Thermo-Lag.
The formation of heat-exchanging char coating on the surfaces of the sublimating Thermo-Lag continues to function as a cellular insulation, and a radiating shield to further delay heat penetration.