Scaling Effects on Color and Transparency of Multilayer Polyethylene Films in Polarized Light

Abstract Transparency and color of polyethylene film layered packages change with the number of layers. When polyethylene layer thickness is between 50 μm and 200 μm, each additional subsequent layer in the package leads to an abrupt change in color and transparency. Polarized light optical effects can be used to manufacture packaging films and labels with forgery protection. A significant influence of the scaling factor on the latent effect and optical properties of the film package is demonstrated for one to six layers with the total thickness of 200 ± 50 μm. Prior thermal treatment of individual layers before they are assembled into a package or assembled package heat treatment change the laminate color. This allows hidden marking and recording text or graphics on the multi‐layer films, not visible under normal lighting conditions, but appearing when viewed in polarized light, or through the polarizer. The paper demonstrates obtaining bright colored decorative or packaging materials, along with light filters for advertising and information displays, which change color with the viewing angle. New materials can be prepared using standard industrial equipment and widely used polymers. By changing the location of the film polarizers, the number of layers and the film thickness, laminates vary in brightness and color from blue to red.