The fire prevention principles of fireproof coatings can be roughly summarized into the following five points:
(1) The fireproof coating itself is not combustible, so that the protected substrate does not come into direct contact with oxygen in the air;
(2) Fireproof coatings have a lower thermal conductivity, which delays the conduction rate of high temperature to the substrate;
⑶. The fireproof coating decomposes into non combustible inert gases when heated, diluting the combustible gases produced by the protected object during thermal decomposition, making it less flammable or slowing down the combustion rate.
(4) Nitrogen-containing fireproof coatings decompose into NO, NH3 and other functional groups upon heating, which combine with organic free radicals to interrupt the chain reaction and lower the temperature.
(5) The intumescent fireproof coating expands and foams when heated to form a carbon foam insulation layer to seal the protected object, delay the transfer of heat and base material, and prevent the object from burning or strength reduction due to temperature rise.
Ultra thin or thin
The fire and heat insulation principle of ultra-thin or thin steel structure fireproof coating applied on steel structure is that the fireproof coating layer expands and foams when exposed to fire to form foam. The foam layer not only insulates oxygen, but also has good heat insulation performance because of its loose texture, which can delay the speed of heat transfer to the protected substrate; According to the analysis of physical and chemical principles, the process of foam layer produced by coating expansion and foaming presents an endothermic reaction due to volume expansion, and also consumes the heat during combustion, which is conducive to reducing the temperature of the system. The effects of these aspects make the fireproof coating produce significant fire and heat insulation effects.
Thick steel structure
The fire insulation principle of thick steel structure fireproof coatings applied to steel components is that when the fireproof coating is exposed to fire, the coating basically does not change in volume, but the thermal conductivity of the coating is very low, delaying the speed of heat transfer to the protected substrate. The coating of the fireproof coating itself is non combustible, serving as a barrier and preventing thermal radiation to the steel components, Avoiding direct attacks from flames and high temperatures on steel components. In addition, some components in the coating react with fire to generate incombustible gases, which is an endothermic reaction and consumes a large amount of heat, which is beneficial for reducing the system temperature. Therefore, the fire prevention effect is significant, providing efficient fire prevention and insulation protection for steel. In addition, this type of steel structure fire resistant coating does not change in volume when exposed to fire, forming a glaze like protective layer, which can isolate oxygen, This prevents oxygen from being in contact with flammable substrates, thereby avoiding or reducing combustion reactions. However, the thermal conductivity of the glaze like protective layer generated by this type of coating is often high, and the insulation effect is poor. In order to achieve a certain level of fire and insulation effect, thick coated fire retardant coatings generally require a thicker coating to meet certain fire and insulation performance requirements.
