PLEOCHROISM OF COLORLESS POLYMER COATINGS ON A REFLECTIVE SURFACE

MSPEYR

Abstract

The optical characteristics of reflective surfaces, double refraction and pleochroism effect in multilayer coatings of metal, glass and plastic packaging made of biaxially oriented isotactic polypropylene (BOPP) of domestic production are investigated. The double-ray refraction generating pleochroism effect in BOPP films causes the color change of reflected light under the condition of light polarization. Polarized light appears because of reflection from a mirror surface of natural or artificial illumination. The share of polarized radiation in the reflected light flux depends on the angle of its incidence on the object and the properties of the mirror dielectric surface. It is proposed to use color effects in polymer films to create an attractive appearance of packaging and its protective marking. Protection of goods packaging from adulteration is an important social and economic problem of modern society. Protective labeling in combination with information coding provides consumer safety of goods of chemical industry and caustic household chemicals, in particular income generation by manufacturers of high-tech and knowledge-intensive products. Coding and the possibility of guaranteed recognition of protective information on transparent polymer packaging depends on the contrast and color difference of structural elements of the bar code or trademark. The paper presents the results of instrumental measurements and quantitative estimates of reflected radiation. The optimal number of layers of transparent polymer film to achieve the necessary contrast of protective marking is established. The necessary results are achieved using films of large-tonnage polymers produced by the domestic chemical industry and widely used in the packaging of goods.