What proof is there that the EcoClean™ coating is working? The primary indication of whether EcoClean™ is working is the look of your building. You will notice that the building panels exposed to sunlight are cleaner than those of the surrounding buildings. The reaction that enables the building surface to maintain its appearance works equally in removing smog and other pollutants. In order to prove the smog-busting capabilities of EcoClean™, Alcoa reached out to Air Quality Sciences, Inc. (a UL company), located in Marietta, Georgia, USA, to conduct independent testing. Their findings confirm that on a molecular level EcoClean™ neutralizes smog (nitrogen oxides / NOx).
Does EcoClean™ change the appearance of the paint finish? Yes. It can be expected that the addition of a clear coat to any painted base coat surface will slightly change that surface’s appearance. The translucent EcoClean™ coating will affect color and gloss slightly compared to non-EcoClean™-coated products with that same color. For that reason, EcoClean™-coated panels should be treated similarly to metallic colors: Alcoa recommends that EcoClean™-coated and non-coated panels of the same color not be installed on the same visual plane.
Is smog really as important an issue as it was years ago? EcoClean™ works on all types of organic pollutants, of which smog is just one. Smog, sulphur oxides (SOx), diesel exhaust and other organics are all attacked by EcoClean™; however, for simplicity’s sake, we have chosen smog as our focus. A 2002 study of more than 3,000 children living in 12 southern California cities, published in a leading medical journal, The Lancet, showed data suggesting that smog not only exacerbates asthma but causes it as well. As recently as June 22, 2007, a CBS news article cited that “more than 3,700 deaths each year are caused by cardiovascular and respiratory illnesses” and that the most vulnerable are children.
What are hydrophilic and superhydrophilic? Hydrophilic and superhydrophilic describe surfaces that attract water instead of repelling it. Instead of beading up, water will flatten and sheet off on both horizontal and vertical surfaces.
Why is EcoClean™ different from other coatings claiming cleaning properties? Alcoa’s EcoClean™ coating is a photocatalytic coating that destroys organic pollutants in a reaction with UV light. It is also superhydrophilic, meaning it combines both active and passive cleaning. Other coatings and paints are hydrophilic surfaces and depend upon water to wash away the dirt or they depend upon dirt’s not sticking to the surface. Therefore, they employ only passive cleaning.
What is the difference between EcoClean™ and other technologies that claim self-cleaning properties and show photos of water beading up on a panel’s surface? EcoClean™ is superhydrophilic – meaning that it loves water, while others are hydrophobic in nature – water hating. Thus, water does not bead up on the surface of EcoClean™ like you see on competitors’ materials; rather it spreads out and wets the surface completely. With EcoClean™, dirt is undercut and washed off. With a hydrophobic surface, water will bead up – carrying dirt as the beads roll down the panel’s surface. Unfortunately, water beads leave streaks as well as concentrations of dirt on the bottom-most building panels where the beads evaporated.
Has an equivalent of EcoClean™ been developed and promoted by someone else? Titanium dioxide (TiO2) is a compound that naturally attacks organic pigments in paint. Alcoa has developed a unique coil-coating process that not only protects the paint but also enhances the paint finish’s performance. To our knowledge, EcoClean™ does not resemble other offerings available. Alcoa has patents pending for this coating system and the method to apply it.
What makes coil coating different from or superior to post-applied versions of titanium dioxide? Post-application of titanium dioxide by hand roller or spray is a much more expensive option than the coil-coating method employed with EcoClean™, and that prohibitively high cost, a direct reflection of those manual application methods, has limited titanium dioxide’s use on building exteriors. The EcoClean™ coil-coating application technology is not only more economical but it is also completely compatible with paint and does not attack its components. We feel this solution will enable more architects and building owners to take advantage of the benefits this technology offers.