Sedimentation method to evaluate PFI mill beating degree of wood pulp fibers

A sedimentation experiment was used as a simple method to evaluate the PFI mill beating degree of wood pulp fibers. The sedimentation volume decayed exponentially with elapsed time. The sedimentation rate, k, changed with the beating degree, though the equilibrium sedimentation volume remained relatively constant. The rate k decreased with the increasing concentration, c, and the beating degree; and moreover, k^-1 was proportional to c. This result suggests that k^-1c^-1 can be a unique factor for the beating degree. The factor expresses the beating degree well and can also tell us that the single fiber properties are more important than inter-fiber interactions during the sedimentation process of the CSF measurement.