Reflectivity of iridescent coextruded multilayered plastic films

Abstract

Abstract Coextruded plastic films containing 231 alternating layers of polystyrene and polymethylmethacrylate have been made with individual layer thickness in the range of .06–0.1μ. Due to the difference in refractive indices these unique films can be made to reflect portions of the visible spectrum, yielding a highly iridescent appearance. Reflectivity measured on films of known layer thickness distribution correlated with values predicted from optical theory.