Change in colour of dyed aramid fabrics by sputter etching

The aramid fabrics Technora and Conex, dyed with CI Disperse Yellow 54, CI Disperse Red 60 and CI Disperse Blue 56, were treated with sputter etching and argon low-temperature plasma. The colour depth of Technora was considerably increased by sputter etching, whereas that of Conex was not. Changes in colour were investigated by the L*, C*, h colour system. The increase in colour depth due to sputter etching was greatly dependent on the decrease of metric lightness L* and the increase of metric chroma C*.