The tear strength, which depends highly on the strength of the individual fibers, actually decreases with refining. Refining of pulp increases their flexibility and leads to denser paper. This means bulk, opacity, and porosity values decrease with refining. This tends to roughen the fiber surface, with minimal fiber cutting for improved fiber-fiber bonding. In most cases, however, it is desirable to minimize fiber cutting to maintain high paper strength.
Drainage is the ease of removing water from pulp fibers, either by gravity or mechanical means.
CSF is a measure of drainage and a useful means for determining the level of refining. Average fiber length statistical average length of fibers in pulp. The coarseness of fibers has an important effect on many properties of paper. 100 m. Pulp used to be treated in beaters , such as the Hollander beater, but now refiners are used. The terms beating and refining are often used interchangeably, but refining is applicable to most modern equipment.