Introduction
It is an old papermaker\u27s adage that paper is made in the beater. This means that the performance and the physical properties of the paper are determined by the type and the extent of the mechanical action to which the fibers are subjected before they are joined to form paper. The terms used to describe the function of refining; free beaten, wet beaten, et al are all traditionally vague, by reason of the complicated structure of the fibers and the even more complicated changes these fibers undergo during the refining process