The incidence of pressure on the colour of compacted powders

This paper examines the effect of densification on the colour of compacted powders and considers whether the link is between colour and texture brought about by compaction pressure or by particle rearrangement. A methodology is established to qualify and quantify the colour and the texture of a free powder and its compact. This is done by measurements of the diffuse reflectance spectra (DRS), and experimental results are presented for the relation between densification characteristics and colour for compaction pressure of up to 30 kN.