Method for making a low density multi-ply paperboard with high internal bond strength

摘要

Methods for improving the internal bond strength of paperboard with greater than 25 percent crosslinked fiber in at least one ply are described. In the methods, additives are added to the slurry in various combinations and order while maintaining the ionic demand of the slurry at less than zero. Paperboard with high ZDT, Scott Bond and Taber Stiffness is obtained.