18 Sep 2002
Consumers across Europe can now purchase self-cleaning glass that promises to keep windows free from dirt.
Pilkington is launching its self-cleaning glass across Europe this month. As of today, consumers in the UK have the opportunity to buy Pilkington's Activ glass and tomorrow the product will make its debut in Italy.
Self-cleaning glass has been the dream of flat-glass manufacturers such as Pilkington for some time. But having cracked the mystery last year, the company initially launched the product in Ireland, Austria and the US. Today, the bandwagon has rolled into the UK en-route across Europe.
"The key to Activ glass is an ultra-thin coating only 40 nm thick," Philip Webb a spokesperson for Pilkington told Optics.org. "It is applied to the glass surface during the manufacturing process."
The coating, which is based on titanium dioxide, works by combining the two beneficial effects. First, the ultraviolet wavelengths in sunlight react with a photocatalyst to break down organic debris on the glass.
"The second feature is that the coating is hydrophilic," says Webb. "This means that when rain hits the glass, it doesn't form droplets. Rain water flows down the glass in a sheet and washes the dirt away." Alternatively, a hose can be used to clean the glass when there is little or no rainfall.
The clever invention comes at a premium price though. Activ is set to cost consumers up to 20% more than conventional glazing. "The coating lasts for the lifetime of the window," says Webb. "Consumers would recoup the excess cost over that time."
Jacqueline Hewett is news reporter on Optics.org and Opto & Laser Europe magazine.