Key material properties in crease cracking of kraft paper

Crease cracking of paperboard is important to control for the appearance and structural integrity packages. affected by creasing operation variables, as well physical properties paperboard. However, effects are not clearly known. The objectives this work were identify key material that affect crease clarify fiber composition starch. Laboratory sheets produced from bleached refined softwood hardwood commercial pulp at grammage thicknesses match a typical To mimic papermaking operations, surface starch was applied via bench-top size press. creased in lab over range penetration depths, reverse-side measured. results showed less correlated with higher tensile post-peak energy, lower bending stress, z-direction (ZD) stiffness. energy measure resistance crack growth fiber-bridging. force ZD stiffness influence forces create cracks. It observed decreasing ratio hard-wood-to-softwood content reducing amount would both decrease cracking.