A colorimetric technique for assessing the mixture quality of fine particle mixtures

Abstract As part of a containing study of the mixing of cohesive powders, late/pigment mixtures were created using either a pestle and mortar or a Lodige mixer. The fine pigment particle `coat' the coarser talc particles, and as the pigment is progressively distributed, so the colour changes. Electron microscopy failed to reveal significant variation in pigment distribution, but comparison of the samples using a KCSIS spectrophotometer gave a satisfactory quantitative assessment of mixture quality.