Evaluation of Long Soaking Times for Rehydration of Recycled Fibers, 1994 Recycling Symposium Proceedings

Gary M. Scott, Said Abubakr

The objective of this research is to investigate the effect of extended soaking times of recycled paper on the hydration of the fibers. Mass transfer limitations and morphological changes in the fibers prevent rapid rehydration, and thus the fibers do not return to a completely rehydrated state. Consequently, the fibers become less flexible and their bonding capability is decreased. This study investigated the effect of extended soaking times of up to 8 h to determine if longer contact with water will improve the hydration of the fiber before disintegration. Chemical addition was also investigated. The fibers were tested for water retention value, which correlates well with the strength properties of the sheet according to the literature. As expected, sodium hydroxide promoted fiber swelling, whereas the effect of calcium chloride was not as definite. Extended soaking apparently decreased the water retention value, probably as a result of the production of fines. The presence of fillers also had an effect on fiber rehydration.