Thermal protection and fireproofing of metals to protect property and human life, save energy and resources, is of great importance. Emisshield™ Metal Coatings have been developed to perform dual roles depending upon the metal type and application. In certain applications for steel, aluminum and other metals, the Emisshield™ Metal Coatings, with their emissivity properties, will absorb energy and reradiate it to a colder body or region. This protects the metal and allows it to withstand higher temperatures. When a cold surface or atmosphere to radiate to does not exist on the coated side of the metal, the emissive properties will increase the rate of heat transferred through the metal. This is because the backside (furthest from heat source) of the metal will be colder than the surroundings.
An example of this is in boiler tubes where Emisshield™ Metal Coatings will increase the conductive heat transfer, prevent scale buildup, provide uniform heat, stabilize temperatures, and increase the service life of the tubes. Resulting from these actions is another added benefit, increasing production for the same thermal load.
Emisshield™ Metal Coatings have also been developed for fireproofing applications. Technical advances utilizing emissivity and insulation work hand-in-hand to protect the metal surface during a fire. This is possible because the emissive characteristics will redirect the heat to a colder body. Emisshield™ Metal Coatings will then prevent memory loss in steel that could lead to catastrophic structural support failures as a result of a fire in a building.
In laboratory tests where carbon steel was coated with Emisshield™ Metal M-1, the metal was able to withstand temperatures of 3500°F for over three hours while it radiated heat back out to the colder atmosphere. The uncoated steel melted through after a few minutes.
Measurements taken with an optical pyrometer showed that the back face temperature (not directly exposed to the heat source) of an Emisshield™ Metal coated piece of carbon steel was over 1000°F cooler than the back fact of an uncoated piece of carbon steel. This demonstrates the emissive properties of the coating. Instead of transferring the heat through the piece of metal to the backside, the energy was reradiated away from the surface towards the colder atmosphere.
Emisshield™ Metal was tested in the Wessex Lab for resistance to acid corrosion (ASTM C980). The results indicate that Emisshield™ will be a great benefit to structures where steel will be exposed to weather. Bridges and other infrastructures can be protected from these effects thereby making them safer for people and giving those structures a longer lifespan.
