Fiber processing characteristics with bark extractives of Acacia mearnsii De wild.

It is well known that the bark of Acacia mearnsii De wild. contains large quantities of condensed tannins. In this work, adsorption of A. mearnsii bark extractives on various fibers was investigated to prepare functional textile goods. Seventy percent acetone aqueous extractives from the bark were treated with water at 100 degrees C for 20 min together with multifiber adjacent fabric, the warps of which are composed of nine kinds of fibers (polyester, silk, acrylic fiber, rayon, woof, acetate, vinylon, nylon, and cotton), and the dyeing affinity of each fiber was evaluated by comparing the K/S value which was calculated according to the Kubelka-Munk equation. It has been made clear that proteinic fibers (silk and wool), vinylon, and nylon have great affinity and that cellulose fibers (cotton, rayon, and acetate), polyester, and acrylic fiber on the contrary have very little affinity. When 70% acetone aqueous extractives from the steamed bark were used, greater dyeing affinity was observed on every fiber than those from the untreated bark. It also was confirmed that polyphenols as well as the coloring materials in the bark were adsorbed on fibers, and especially, adsorption rates of polyphenols on vinylon and nylon were very large. Furthermore, it was found that nylon treated with a copper acetate aqueous solution after having been processed with bark extractives, had antibacterial activity against Escherichia coli.