Effect of low temperature plasma treatment on color of wool and nylon 6 fabrics dyed with natural dyes

In a previous article, we reported that oxygen low temperature plasma treatment of wool fibers increases both the dyeing rate and saturation dye exhaustion of acid dyes, despite increased electronegativity of the fiber surface with the treatment. In this article, wool and nylon 6 fabrics treated with oxygen, carbon tetrafluoride, and ammonia low temperature plasmas are dyed with several natural dyes, such as cochineal, Chinese cork tree, madder, and gromwell. The dyeing rate of the plasma-treated woof increases considerably with cochineal, Chinese cork tree, and madder, but not with gromwell. However, the dyeing rate of nylon 6 with cochineal and Chinese cork tree is not changed by the plasma pretreatment. Furthermore, plasma-treated wool fabrics dyed with cochineal and Chinese cork tree have increased brightness compared with untreated wool.