Fireproof coatings for expanded steel structures

Fireproof coating for expanded steel structure is a single-component self-drying coating composed of ethyl fiber, chlorinated paraffin, fireproof pigment, auxiliary agent, solvent, etc.

Fireproof coating for expanded steel structure: the coating expands and foams at high temperature to form a fireproof coating for steel structure with a fire-resistant thermal insulation protective layer. The industry is accustomed to using the old code name, that is, the expansive fireproof coating is a collection of ultra-thin structural fireproof coating and thin steel structure fireproof coating

Steel is a kind of non-burning building material, it has seismic, bending and other characteristics. In practical application, steel can not only increase the load capacity of buildings, but also meet the needs of aesthetic modeling of architectural design. It also avoids the defects that building materials such as concrete cannot bend and stretch. Therefore, steel has been favored by the construction industry, single-storey, multi-storey, skyscrapers, factories, warehouses, waiting rooms, departure halls and other steel is common. However, as a building material, steel has some unavoidable defects in fire prevention, and its mechanical properties, such as yield point, tensile and elastic modulus, will decline sharply due to the increase in temperature.

Steel structure usually in 450 ~ 650℃ temperature will lose the bearing capacity, a great deformation, resulting in steel column, steel beam bending, the result is too large deformation and can not continue to use, generally unprotected steel structure fire resistance limit of about 15 minutes. The length of this time is also related to the speed of heat absorption of the component.

The thin-coated steel structure fireproof coating refers to the steel structure fireproof coating whose coating thickness is greater than 3mm, less than or equal to 7mm, has a certain decorative effect, expands and thickens at high temperature, and the fire resistance limit is within 2 h. This kind of fireproof coating for steel structure is generally composed of a suitable water-based polymer as the base material, and then composed of a composite system of flame retardants, fire retardant additives, fire-resistant fibers, etc., and its fire prevention principle is the same as ultra-thin type. For this type of fireproof coating, the water-based polymer required to be selected must have good adhesion, durability and water resistance to the steel substrate. Its decoration is better than thick fireproof coatings, inferior to ultra-thin steel structure fireproof coatings, and the general fire resistance limit is within 2 h. Therefore, it is commonly used in steel structure fire protection projects with less than 2 h fire resistance limit, and spray construction is often used. In one period, it occupied a large proportion, but with the emergence of ultra-thin steel structure fireproof coatings, its market share was gradually replaced.

Scope of application

Ultra-thin steel structure fire retardant coating (expanded steel structure fire retardant coating) is used in airports, power plants, petrochemical, stadiums, commercial squares, industrial factories and mines, high-rise buildings and other indoor exposed steel structure fire protection.

Principle of fire and insulation

The fire insulation principle of the ultra-thin or thin steel structure fire retardant coating coated on the steel structure is that the fire retardant coating layer expands and foams when subjected to fire, forming a 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 the foam layer generated by the expansion of the coating due to the expansion of the volume and endothermic reaction, but also consumes the heat during combustion, which is conducive to reducing the temperature of the system, the role of these aspects, so that the fireproof coating has a significant fire insulation effect.