Low-Emittance (Low-E) is a term used for a surface that radiates, or emits, low levels of radiant energy. Emittance refers to the ability of a materials surface to emit radiant energy.All materials absorb, reflect and emit radiant energy. Emissivity is the value given to materials based on the ratio of heat emitted compared to a blackbody, on a scale of 0 to 1. A blackbody would have an emissivity of 1 and a perfect reflector would have a value of 0. Reflectivity is inversely related to emissivity and when added together their total should equal 1. Therefore, if asphalt has an emissivity value of 0.90 its reflectance value would be 0.10. This means that it absorbs and emits 90% of radiant energy and reflects only 10%.
Conversely, a low-e coating such as Laser Gold has an emissivity value of 0.03 and a reflectance value of 0.97, meaning it reflects 97% of radiant energy and emits only 3%.
A copper foil > .001″ thick (0,025 mm) is coated with Laser Gold for the ultimate thermal control barrier.
The auto race car market has driven the need to protect carbon fiber components from the blistering heat generated by the engine and exhaust system.
While many of the carbon fiber parts are Laser Gold coated by directly plating the plastic substrate, the requirement to have a ductile, flexible “wrapping” material drove the development of the Laser Gold coated copper “Thermal Foil”.
The foil is applied on site using a 3M spray adhesive.
Although happy with the remarkable performance of the copper foil, the Formula 1 teams are continuously seeking lighter and lighter materials. To satisfy this need, Epner Technology is developing a Laser Gold coated high temperature Kapton foil, less than half the weight of the copper.