Fire protection mechanism of fire retardant coatings

Summary:  

The fire protection mechanism of fire retardant coatings can be roughly summarized into the following five points:

(1) The fire retardant coating itself is flame-retardant or non-combustible, so that the protected substrate does not directly contact the air, delaying the ignition of the object and reducing the burning speed.

(2) In addition to its own flame retardancy or non-combustibility, the fire retardant coating also has a low thermal conductivity, which can delay the transmission of flame temperature to the protected substrate.

(3) The fire retardant coating is heated to decompose the non-combustible inert gas, dilute the flammable gas decomposed by the thermal decomposition of the protected object, so that it is not easy to burn or the burning speed is slowed down.

(4) Nitrogen-containing fire retardant coatings decompose NO, NH3 and other groups when heated, and combine with organic free radicals to interrupt the chain reaction and reduce the temperature.

(5) The intumescent fire retardant coating expands and foams when heated to form a carbonaceous foam insulation layer to seal the protected object, delay the transfer of heat and the substrate, and prevent the object from catching fire or the strength caused by the increase in temperature decline.