STUDIES ON PRACTICAL ASPECT OF NEUTRAL AND ALKALINE SIZING

Abstract

Internal sizing is achieved by retarding the rate of penetration of a fluid; usually water, through capillaries formed both within and between fibers. The rate of capillary rise of fluids into paper has been effectively described by the Washburn equation and modifications of it. These approaches assume 'that the penetration of a fluid into paper is analogous to that of a fluid into a single capillary. Retardation is thus brought about by the creation of a low energy hydrophobic surface at the fiber-water interface which increases the contact angle formed between a drop of liquid and the surface and thus decreases the wettability...............