FUNDAMENTALS OF STRENGTH LOSS IN RECYCLED PAPER

One of the most challenging aspects of recycling is understanding the cause of loss in potential fiber bonding when fibers are dried. Since mechanical pulps do not seem to suffer from the same problems as chemi cal (low yield) pulps, difficulties in paper recycling seem to be rela ted to the structure of the lignin-free cell wall. The damage usually manifests itself in hornification and surface inactivation of the fibe rs. Various ideas proposed on the cause of hornification and surface i nactivation in predried cellulosic materials are reviewed, and the imp ortance of the hornification is pointed out. Areas of necessary furthe r research on cellulose (fiber) are outlined.