The activity of chromium still remained incomplete after the single stage chemical treatment; as a result the tensile properties increased less over the raw coir fiber. However after the double stage treatment chromium became fully occupied in reducing hydroxyl groups,
which in turn increased the tensile properties of coir fiber compared to both raw and single stage treated coir fibers (Fig. 12).
The Shaking time is very important.
The reaction rate accelerates during shaking.
Shaking in solution also cleans the fiber surface.