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Home » Volume 27, 2012 » Issue No. 5
MECHANICAL PULPING
Development of TMP fibers in LC- and HC- refining
Rita Ferritsius, Sofia Reyier Österling, Olof Ferritsius
Abstract
Low consistency (LC) refining and high consistency refining (HC) has been studied in a TMP mill. When strength properties were increased, the development of fiber properties was different in LC- and HC-refining. Fiber curl decreased in LC-refining but increased in HC-refining. LC-refining decreased fiber curl and increased tensile index simultaneously in this study. It is therefore likely that the decreased fiber curl contributes to the increase of tensile index in LC-refining. Furthermore, fiber wall thickness decreased and external fibrillation increased in HC-refining, while these properties were only slightly influenced in the LC-refining. Fibrillation was found to decrease in most cases for LC-refining while fiber wall thickness index increased slightly but consistently, which might indicate a less dense structure of the fiber wall or its surface layers.
Double-disc HC-refining with the same energy input as in a conical single-disc refiner resulted in fibers of higher external fibrillation, lower fiber wall thickness and higher fiber curl at a given fiber length.
The results indicate that analyzing individual fiber dimensions could be a better tool for understanding how fibers develop in different kinds of refining than analyzing conventional handsheet properties.
Keywords
BIN, Disintegration, Fiber curl, Fiber dimensions, Fiber wall thickness, Fiber width, Fibrillation, HC-refining, LC refining, Mechanical pulp, Sheet properties, TMP
Pages
860-871
Full text
PDF Document N2012-27-05-p860-871-Ferritsius.pdf (1314KB)
Development of TMP fibers in LC- and HC- refining (2012-27-05-p860-871-Ferritsius.pdf)