Mechanical Pretreatment Effects on Fiber Properties

摘要

Controlled mechanical pretreatment on wood pulp before refining caused significant pulp fiber property changes. We used Hobart mixer as a mechanical pretreatment device. After pretreatment of five different kinds of pulp fibers for 1 to 3 hours at ambient temperature (20□), we obtained improvement of WRV(Water Retention Value) without loss of their fiber lengths at the same freeness levels. Fiber surface area measurements and the electron microscope analysis after mechanical pretreatment have indicated extensive internal delamination inside the pulp fibers. The fiber property changes, which occurred before refining, were maintained throughout the refining process. The degrees of fiber property changes were different from one another. The mean fiber length, its chemical composition, and the wet fiber flexibility of the furnish seemed to be important factor to determine the effectiveness of the pretreatment. The mechanical device itself can be another very important factor. Efforts are being made to design more effective mechanical device.