光学的方法によるパルプ繊維のフィブリル化の評価

抄録

This paper describes a new optical method for an evaluation of the state of the state of fibrillation of paper making fibers. The optical system consisting of laser light source, glass cell, optical lens and photocells, can measure the light transmitting and scattering properties of dilute pulp suspension (00.0496 consistency).
It was found that turbidity defined as ln (I₀/I) increases linearly with the increase consistency of suspension, and an inclination of the line, corresponding to the light absorption coefficient, increases with beating. Plotting the light absorption coefficient against Canadian Standard Freeness gives a sigmoid curve. On the other hand, the relationship between the specific surface area by hydrodynamic method and the light absorption coefficient is linear. It is observed that the light absorption coefficient of hardwood bleached kraft pulp is larger than that of softwood bleached kraft pulp, compared at the same specific surface area.
These findings reveal that the optical properties of pulp suspension are closely related to the morphological change of fibers. They also suggest that there is a possibility of evaluating separately the internal and external fibrillation of beaten pulp.