Refining the Chemical Pulps

After presents a brief description of the refiners evolution, this chapter focuses on what happens inside the refiners, that is, on the mass flow distributions inside the refiners, on how the flakes in suspension are captured by the bars of the refiners’ discs, and how energy is transferred to the pulp causing the desired changes in the fibers in suspension. The effects of refining on fibers are described and classified according to the structural changes caused to the fibers as well as according to the direct effects of these changes on the properties of the paper produced. Effects on paper machine runability are also presented and discussed.