Automated Instrument for Measuring Various Physical and Chemical Pulp Properties - Application of the Das Jar Theory to Online Refiner Control, 2001 Papermakers Conference Proceedings

A refiner controller based on the DAS Jar theory is introduced. The controller optimizes refining by monitoring specific surface area and specific volume of pulps. The fundamental nature of these parameters provide greater insight into the pulp refining process compared to the currently used measurements such as freeness.

The versatility and power of this new technique are highlighted by three experiments. First, fines generation and fibrillation are separated in a typical beating curve. Then, samples of similar freeness are discriminated based on their surface area. Finally, the instrument shows substantial differences between four highly refined pulps that cannot be tested for freeness.

The rapid determination of the specific surface area of the whole pulp and the fines-free pulp enables the complete characterization of surface development. The quantification and separation of fines generation and fibrillation provides a unique control strategy to optimize the refining process, save energy and achieve ultimate sheet properties.