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My TAPPI Story: Naomi Gehling
T. Okayama, N. Yoshinaga & Y. Take
Tokyo University of
Agriculture and Technology
Chemical pulp fibers are irreversibly changed by recycling. The change of the surface of a single pulp fiber during recycling was characterized by contact angle measurements using appropriate test liquids. Remarkable increase in contact angle of water was found after recycling. Recycling treatment did not substantially change the surface free energy of the fiber. However, the base parameter of the surface free energy decreased with recycling, particularly that based on free-drying at high temperature. Two types of penetration measurements were designed to measure rate of transverse (Z direction) and lateral (X-Y direction) liquid penetrations into paper. The rate of water penetration increased with recycling. It correlated with a porous structure in the recycled pulp handsheet. The tortuosity factor for the handsheet was calculated using the Lucas-Washburn equation. The recycled pulp gave smaller tortuosity factors of the handsheet compared with the virgin pulp.
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Available for Purchase – Conference Proceedings
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Effect of Recycling on Wetting and Liquid Penetration of Paper, 1995 Coating Conference Proceedings