New coating offers enhanced fire and corrosion protection
Researchers from Nanyang Technological University, Singapore and national industrial developer JTC came up with this idea when they were figuring out a commercially viable solution to protect reinforced concrete against underground fires.
Less laborious to apply
Named “Firoshield”, the new coating is cheaper and less laborious to apply, and can function aesthetically like normal paint. Existing steel structures in buildings are usually coated with a fire-retardant layer to shield the bare metal from damage by fire and meet the fire protection standard of two hours – aimed at giving occupants enough time to evacuate the building. Today’s conventional intumescent coatings are thick, more expensive and laborious to apply.
No need for sand blasting
In contrast, this coating can be applied on bare steel without the need for sand blasting to prepare the surface and will protect the material against fire for two hours without falling off. The overall coating time can hence be reduced by half as compared to conventional coatings which translates to lesser man-hours required. The product has also been tested on other construction materials, such as reinforced concrete and laminated timber, and has the same excellent performance.
Five layers of coating
To achieve a two-hour fire rating, the coating requires just five layers of coating, compared to conventional coatings, which requires up to 15 layers or more. It is thus two times faster to apply and is cheaper by about 50 percent due to its lower materials cost and manpower requirements. In addition to its fire resistant properties and easy application, the coating can also protect the steel surface from corrosion, which no other fire coatings in the market can do at the moment.
The coating is expected to last longer when exposed to weathering elements such as moisture and ultraviolet rays. Its performance barely dipped by two percent, as compared to the drop of up to 75 percent for conventional coatings when subjected to weathering tests in the lab. This will reduce the maintenance cost and frequency of inspections over the lifespan of a building.
Balanced mix of additives
The team said the knowledge that they have obtained over the years of research on the different aspects of polymers and combustion, combined with civil and structural engineering experience, helped to streamline their approach. The strength of their coating comes from a balanced mix of additives, which work well together to give off simultaneous chemical reactions when faced with extremely high temperatures. “In a fire, our coating forms a compact charred layer that acts as a protective barrier against the heat,” said Prof Aravind Dasari, who is leading the team.
Combination of materials
The base material of the new coating is made of synthetic resins, which are polymers commonly used to make paints. To give it fire and corrosion-resistant properties, the team added a combination of common chemicals, including one that is endothermic – absorbing heat to start a chemical reaction that cause the coating to adhere firmly to the steel. The team went further to develop a coating that is able to have assorted colours; pigments can be added to the mixture so it achieves the aesthetic function of normal paint.
Commercialisation is straightforward
Paint manufacturers looking to add the benefits of the coating to their products should find that commercialisation is straightforward, as the innovation relies simply on the addition of key chemicals into their paint manufacturing process. For the next phase of development, the product will be sent to the UK for an industry certification, which includes a load-bearing fire test that no facilities in Singapore can do currently.