Prediction of Reflectance of Paint Films Using Many-Flux Theory and its Comparison with Experimentally Measured Values

Abstract

Color developed by the pigmented object is attributed to scattering and absorption of light by pigments. In applied colorimetry, the interaction of radiant energy with pigments is trated using two flux, Kubelka-Munk theory, which is a highly simplified version of radiative transfer theory. To overcome the limitations of K-M theory, the mathematical models with four and six flux are proposed in the literature. Recently Mudgett and Richards have developed the multiple scattering equations, enable to handle as many as forty flux in the turbid media. In the present study, the attempts are made to predict the reflectance of three paint dispersions e.g. titanium dioxide, phthalocyanine green and iron oxide-red pigments using many flux equations. The particle sizes required for computations are determined using light scattering and electron microscopy methods. The predicted reflectances are compared with the experimentally measured values of the paint films, using recording type Shimadzu spectrophotometer equipped with integrating sphere. The predicted results moderately agree with experimental results. The discrepancies between theoretical and experimental values have been discussed.