Z. Wang et J. Gullichsen, Towards more uniform kraft cooking - Part 2. Strength properties of several Scandinavian softwoods, PAP PUU, 80(8), 1998, pp. 606-612
The strength properties of pulps made: from wood chips originating from dif
ferent parts of the stem and different growing conditions (stands) were inv
estigated in this study. Spruces are superior to pines in terms of tensile,
tear and burst index. The beating energy consumption decreases from the bu
tt towards the top of the stem when beating to a given Schopper-Riegler (SR
) number. There is no obvious trend for tear strength at a specified tensil
e strength at different heights of the stem. It varies between different st
ands and species, depending on wood density and fibre length. Pulps contain
ing pin chips are easily beaten to a high SR number under the same beating
conditions. However, they have poorer strength properties than pulps contai
ning no pin chips.