Improving the bending stiffness of multi-ply folding boxboard with maple HYP
BCTMP (Bleached chemi-thermo-mechanical pulp) or HYP (high-yield pulp) is an important sector in the Canadian market pulp business, and most of them has been exported to Europe and Asia and over half of it is used as middle-ply furnish in Folding Boxboard (FBB). FBB requires high bending stiffness for crush resistance, z-directional strength for preventing delamination, surface smoothness for good printing, and good die-cutting performance for conversion. Maple HYP has been known to be the premium pulp in the middle ply of FBB since it has a very high bulk. In this project, we will determine the difference in fiber stiffness and compressibility as well as bulk formation mechanism between maple and eucalyptus HYP. This will help identify the potential advantages of using maple in FBB and develop practical strategies to maximize the contribution of maple HYP to bulk and bending stiffness as well as other properties of FBB.