Mini-Encyclopedia of Papermaking Wet-End Chemistry
Part Three: Equipment & Unit Operations


The word "beating" is often used as a synonym for "refining." Both words refer to the passage of a fiber slurry between a rotor and stator or counter-rotating disks. Raised areas of "bars" on each surface expose the fibers to repeated compression and shearing forces. These forces gradually delaminate the fiber cell wall, increasing flexibility and fibrillation of the fiber surfaces. The expression, "paper is made in the beater," has been passed down from the days in which most pulp was prepared batch-wise in an oblong tub with a central baffle along its lengthwise direction. Rotation of a cylinder with raised bars on its surface against a bedplate caused fiber circulation as well as refining action.

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This page is maintained by Martin hubbe, Associate Professor of Wood and Paper Science, NC State University, .