Reflection enhancement of aluminum strips by EB-PVD in highly productive industrial lines

In recent years, the improvement of energy efficiency has become an urgent issue in industrial countries. Reflector materials with enhanced reflectivi ty open up the possibility of increasing lighting efficiency in order to ec onomize the illumination energy. Meanwhile, large-area coating of aluminum strips by EB-PVD in order to achieve enhanced optical reflectivity of up to 96% has been established in industry for the purpose of reflector mass pro duction. The reflection increasing layer system consisting of three layers of aluminum, silicon dioxide and titanium dioxide is coated on aluminum str ips, which are up to 1250 mm wide. The latest production start of such a ne w air-to-air coating line, allowing strip speeds of at least 20 m/min, occu rred some months ago. The process management of the individual EB-PVD proce ss steps and the ellipsometrical online layer measurement on the moving str ip will be presented. The highly productive air-to-air coating line for lon g time deposition cycles of up to 120 production hours without interruption will be introduced. Finally, this paper has analyzed the coating results o n anodized as well as lacquered strips, and discussed tendencies of product development. (C) 2000 Elsevier Science B.V. All rights reserved.