The moisture content (mc) of wood is of great importance to several processes in mechanical pulp mills. Debarking, chipping, refining and indirect bleaching are factors that are affected by the mc of the wood. The mc varies within a log, mainly between heartwood and sapwood, but also within the sapwood, where mc often varies significantly. This study aims to describe the variation in the mc of pulp logs of Norway spruce (Picea abies) arriving at Braviken paper mill in southern Sweden. 574 discs from 82 logs were sampled in April, June and October, respectively. Of the sampled discs, 164 were divided into 8 equal pieces, and the heartwood content of each piece was determined. Mc values were determined for all discs. The results showed a high variation in the mc values, with up to a 25 % difference in mc within a single disc. The average difference in mc within a single disc varied between the different sampling periods, from 7.2 % in October up to 11.0 % in June.
Keywords: moisture content, pulpwood, Norway spruce, Picea abies, disc
Authors
Hultnäs M.
Department of Forest Products, Swedish University of Agricultural Sciences, Uppsala
Jonsson M.
Department of Forest Products, Swedish University of Agricultural Sciences, Uppsala
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