Determining gloss of opaque protective and decorative coatings on wood and wood-based materials

Abstract

A significant problem in the production of furniture is an objective assessment of the reflective properties of coating surfaces by gloss. Instrument readings are influenced by various factors such as color, saturation, lightness of the surface, roughness of the coating surface under study, the refractive index of a colored substance, etc. The calculations showed that the coefficients of absorption and reflection of visible radiation for colored substances are insignificant over 10 %. Although when light is reflected from the surface of a colored substance, the dominant wavelength range of the visible radiation spectrum is observed, which characterizes color, but its energy characteristics in relation to the reflected flux are insignificant. The total reflected flux characterizes the gloss of the coating, and the dominant color flux characterizes the color of the substance. For colored substances, it is not possible to use the refractive index in optical calculations. When absorbing and reflecting the visible spectrum of radiation from colored substances, anomalous dispersion is observed (the values of the refractive index change according to various dependencies inside the light absorption band and beyond it). The use of known gloss meters for assessing the gloss of opaque colored protective and decorative coatings requires the improvement of existing methods or the development of new ones that allow solving the multifactorial problem of influencing the gloss of color, saturation, lightness and roughness of the studied surfaces.