NC State
F. Onabe and K. Sakurai. Applications of flow visualization technique in wet end chemistry. In Fundamentals of Papermaking, Trans. of the IXth Fund. Res. Symp. Cambridge, 1989, (C.F. Baker & V. Punton, eds), pp 219–249, FRC, Manchester, 2018.


A microcomputer–aided flow visualization system consisting of Strobovision analyzer(SVA) and image processing apparatus was applied to the analysis of the effect of a variety of parameters in wet end chemistry on the flocculation behavior of model stock systems. These are (a)single polymer addition systems and dual component additive systems,(b)low and high filler content suspensions,and (c)colloidal force and hydrodynamic shear force.

Analysis by digital geometry was carried out to represent features of projected images of flocs and fiber network supporting flocs. The flocculation states were represented numerically. It was attempted to test visually and numerically a flocculation hypothesis in a dual component additive system.

Within the scope of the present investigation,there is some limitations in that this system can be applied only for dilute suspensions with concentrations far lower than those of conventional paper stock in a headbox.

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