How to Choose Fire-resistant Coatings?

Fire-resistant coatings are now used in various industries, so what should we pay attention to when selecting and using fire-resistant coatings? How to measure the thickness of fire-resistant coatings?

When selecting fire-resistant coatings, we should pay attention to the following points:

1. Facing fire retardant coatings cannot be used for steel structures. Facing fire retardant coatings are flame retardant coatings that protect flammable substrates such as wood structures, and cannot achieve the purpose of increasing the fire-resistance limit of steel structures.

2. Thin-layered steel structure fireproof coatings should not be used to protect steel structures for more than 2 hours. The reason why the thin coating type fire retardant coating has a low fire-resistance is determined by its own raw materials and fire prevention principles. This type of coating contains more organic ingredients, and the coating only acts as a thermal barrier after forming a carbon foam film at high temperatures. The expanded bubble film has limited strength, is easy to crack and fall off, and the carbonaceous material will gradually ash at 100 C high temperature. Therefore, steel structures with a fire-resistance limit greater than 2 hours must be made with thick-coated steel structure fireproof coatings.

3. Fireproof coatings for indoor steel structures shall not be used directly to protect outdoor steel structures without improvement and effective waterproof measures. Open-air steel structures are exposed to the sun and the atmosphere all year round, sun and rain, and wind and snow cover. It must be water-resistant, freeze-thaw cycle resistant, aging resistant, and can withstand chemical corrosion by acid, alkali, salt and other outdoor steel fireproof coatings. Protect it.

4.In general, do not choose outdoor steel structure fireproof coatings for indoor steel structure fire protection. Because outdoor steel structure fireproof coatings have strict requirements on raw materials in order to ensure their excellent performance, their prices are more expensive than indoor steel structure fireproof coatings. Much more. However, for indoor steel structures in semi-open air or some hot and humid environments, outdoor steel structure fire protection coatings should be used for protection.

5. Thick coating fireproof coating is basically composed of inorganic materials, the coating is stable, and the aging speed is slow. As long as the coating does not fall off, the fireproof performance is guaranteed. From the perspective of durability and fire-resistance, thick coating type fire retardant coating should be used.

6. When important steel column members are protected by fire-resistant coatings, thick fire-resistant coatings should generally be used, and the joints should be thickened. When the bonding strength of the fire-resistant coating used is less than 0.05 MPa, a steel wire mesh connected to the steel member shall be provided in the coating.

7. When heavy-duty fire-resistant coatings are used for load-bearing steel beam members, the heavy joints should be thickened. When there is a steel beam that withstands shock vibration, a beam with a coating thickness greater than or equal to 40 mm, a bonding strength of fire retardant coatings less than or equal to 0.05 MPa, and a web height exceeding 1.5 m, a wire connected to the steel beam should be provided in the coating network.

Fire-resistance coating thickness detection:

The fire-resistance time of the fireproof coating and the coating thickness of the fireproof coating are proportional in a certain stage. The fireproof time of the same fireproof coating is different due to the different thicknesses. But beyond a certain limit coating thickness and fire-resistance time will be unbalanced. Therefore, it is very important to measure the thickness of the fire-resistant coating with a fire-resistant coating thickness meter. Usually we use Linshang LS223 fire-resistant coating thickness meter to detect the thickness of fire-resistant coatings. This coating thickness meter is equipped with two probes F3N3 and F5N3. Users can choose the coating thickness meter that suits them according to the size of the coating thickness they measure. The instrument uses the nondestructive measurement principle of the Hall effect and eddy current effect, which will not cause damage to the coating surface. The instrument has the following characteristics:

1. Simple design and simple operation, just start zeroing and start testing.

2. The probe adopts ruby, which is wear-resistant and corrosion-resistant, which can prolong the service life of the instrument.

3. The instrument can automatically identify the measurement substrate, and has three measurement modes: iron-based measurement (Fe), non-ferrous-based measurement (NFe) and automatic identification (Fe / NFe).

4. The instrument uses an advanced digital probe, which is not easy to be interfered with during measurement and has high measurement accuracy.

Linshang LS223 coating thickness meter, large range is suitable for the measurement of fire-resistant coatings, please contact Linshang official website for more details.