Pulp property development Part III: Fiber residence time and consistency profile impact on specific energy and pulp properties
Journal article, 2016

This paper focuses on the pulp properties obtained from ThermoMechanical Pulp (TMP) CD refiners. Undersampled pulp variables are expanded into an oversampled set of process data, which makes it possible to analyze pulp properties in a dynamic time frame. It is shown that, in order to gain deeper insight into the defibration/fibrillation at a specific energy input, one needs to know the fiber residence time and the consistency profile. Moreover, the fiber residence time in the flat zone (FZ) and conical zone (CD) are intertwined with the consistency out from FZ and CD. Together with an external variable (production), these internal variables are essential for predicting the pulp properties. It is also shown that internal process conditions from different test series can be manipulated in the operating window using a low-frequency gain description obtained from an ARX model. The same mapping procedure can be applied to pulp and handsheet properties (in this paper represented by the tensile index), and this opens for implementation of new optimization routines to find more energy efficient operating points while maintaining pre-specified pulp quality.


helich wg

TMP refiners

Piecewise linear functions

tmp refining processes




Materials Science


Pulp quality models

pulp and paper magazine of canada


Anders Karlström

Chalmers, Signals and Systems, Systems and control

J. Hill

O. Ferritsius

Mid Sweden University

R. Ferritsius

Mid Sweden University

Nordic Pulp and Paper Research Journal

0283-2631 (ISSN)

Vol. 31 2 300-307

Subject Categories

Paper, Pulp and Fiber Technology



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