Study On Kubelka-Munk Double-Constant/Single-constant Theories Based On The Polyester Fabric

Kubelka-Munk(K-M) double–constant /single–constant theories are the basic theories of computer color matching for opaque materials and play an important role in color areas. The actual application effect of computer color matching is far from satisfactory. The key reasons for it lie in its basic theory and the prediction model. As the research object, fabrics have the advantages of being used to study both the K-M double–constant theory and the K-M single–constant theory.Disperse dyes were selected to prepare polyester fabrics and spectrophotometer and high precision computer color measurement instrument were used to measure the optical properties of the fabrics. At the same time, the revised K-M theory was tested. The revised K-M double–constant theory by Yang Li, adopted statistical algorithms to the path, solved some problems in the paper. But it ignored both the limit and the change of optical path. The new two-constant theory has been developed based on the K-M theory. The data shows that the recipes predicted by the new two-constant theory are closer to the actual recipes than the recipes predicted by the single-constant theory. But under the condition of high dye concentrations, the application effect was poor.By means of fabric optical model, the optical parameters of fabrics were analyzed. The result of the experimental data shows that :(1) only at low dye concentration, there was a linear relationship between K/S and the dye concentration C, while, with the rising of the concentration C, the values of K/S were curved downward.(2) The absorption coefficient K increased with the increasing of dyeing concentration, to a certain range, slowed down and tended to a stable value.(3) On the contrary, the scattering coefficient S decreased with the increasing of dye concentration.(4) The additivity color mixing law was inconsistent with the actual, the K and S cannot be additive.(5) In practical application, the K-M theory and the additivity color mixing law should be revised. The fabric optical model was used to fit analysis of the optical parameters K, S and K/S relationship with the dye concentration C. The effect was not obvious and still needed further revision. The own problems of the K-M theory and the additivity color mixing leaded to the K-M double constant/single constant theories a lower success rate at a time in the application of computer color matching.