Coating solution for aircraft lampshade products
The lampshade is coated with a high-reflectivity film by thermal evaporation
Generally, metals with high reflectivity are Ag and Al. Ag has the best reflectivity of 98.2% in visible light with a wavelength of 550 nm, followed by Al with a reflectivity of 91.6%. Al is the only one with high reflectivity in the ultraviolet band 92.8%. It also has a high reflection effect of 98.2% at infrared wavelengths. Therefore, Al is widely used in optical films and car applications such as heat insulation paper, car headlights, etc. However, Al has a big disadvantage in that it is easily oxidized in the atmosphere to form a thin layer of alumina about 20-40 Å. SiO and Al2O3 can be used as a protective film to prevent Al from being oxidized. The high evaporation rate helps to obtain a denser and smooth metal film, and the thickness also needs to be controlled. Too thick will cause the surface to be rough and reduce the mechanical strength. The substrate does not need to be heated, heating will make the film surface rough, cause scattering, and reduce reflectivity.
Source: Dah Young