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Home » Volume 27, 2012 » Issue No. 5
MECHANICAL PULPING
Fibre and fines quality development in pilot scale high and low consistency refining of ATMP
Dmitri Gorski, Kathrin Mörseburg, James Olson and Antti Luukkonen
Abstract
The objective of this study was to characterise and compare the development of fibre and fines properties in high consistency (HC) and low consistency (LC) refining of mechanical pulp. Primary refined pulp was produced using the Advanced Thermo-Mechanical Pulp (ATMP) refining process. Pulps were characterized to evaluate external and internal fibrillation, fibre shape and dimensions, surface area of fines and the proportion of split fibres.
Based on the results, a different mode of fibre development was proposed for LC and HC refining. The LC refining resulted in a greater reduction in the shives content and R30 Bauer-McNett fibre fraction. The reduced R30 fraction considerably increased the middle fibre fractions; however it showed no further development in terms of surface fibrillation. While HC refining resulted in a significant reduction in fibre wall thickness associated with fibre collapse and increase in external fibrillation, LC refining mainly generated structural changes, seen in fibre straightening and increased flexibility.
The HC and LC refined pulps had different property profiles compared at equal handsheet tensile index. The LC refined pulps contained less long fibres and fines but significantly more middle fraction particles. Extensive internal fibrillation of the straighter LC refined fibres appeared to have compensated for lower fines content and external fibrillation, producing well bonded sheets with good tensile strength.
Keywords
ATMP, Energy efficiency, Fibre characterisation, Fibre developement, High-consistency Refining, Low-consistency refining
Pages
872-881
Full text
PDF Document N2012-27-05-p872-881-Gorski.pdf (909KB)
Fibre and fines quality development in pilot scale high and low consistency refining of ATMP (2012-27-05-p872-881-Gorski.pdf)