The influence of refining heterogeneity on paper properties

This paper studies the impact of refining heterogeneity on paper property development and pressability. Three trials were performed in different refining equipment. The results showed that the strength development was due mostly to the water retention value (WRV) and the fiber straightness. Curly fibers require more energy to reach a given strength property. A heterogeneous refining, which in this case was performed by mixing less refined and highly refined pulps in different proportions, increased the energy requirement to reach a given tensile index or tensile stiffness index. The pressability of the pulps was not affected by the refining heterogeneity. At a given WRV, the pulp had the same solids content after dynamic pressing independent of the degree of heterogeneity.