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Refining is an important unit operation in the paper production process and consists in the mechanical beating of the pulp fibres in an aqueous medium. The refining conditions affect fibre morphology, pulp suspension characteristics and paper properties. In this study we investigated the effect of refining intensity - given by the specific edge load (SEL) - on the fibre and paper properties. Lower refining intensity led to lower fibre cutting, lower fines generation, and lower ºSR development. Commercial Eucalyptus globulus bleached pulp was refined in a pilot refiner, using different specific edge loads (0.05; 0.1 and 0.2 J/m) and specific energy consumption of 40, 80 and 120 kWh/ton in order to evaluate paper potential. The highest specific edge load tested (0,2 J/m) resulted in a lower average fibre length, as a result of a higher fibre cutting. The papers produced presented higher mechanical resistance, but increasing refinement energy from 80 to 120 kWh/ton did not improve paper properties. On the contrary, with a lowest specific edge load (0,05 J/m), the papers obtained for different specific energy consumption exhibited lower density (i.e., higher open structure, higher air permeability and lower smoothness).

In this paper we studied the retraction of veneer sheets of a diffuse-porous specie (beech) and a ring-porous specie (oak) during the drying process. For each specie we analysed radial and tangential sections, since the differences obtained relate to vessel distribution across the axial or non axial section. Thus, we studied the following parameters: thickness, moisture content, retraction of axial and non axial (radial or tangential) direction. We used 10 beech logs, from which we took 30 samples with a radial cut and 30 samples with a tangential cut. From each log we took 6 veneer sheets. We applied the same procedure to the oak logs. All our veneer sheets were 0,6mm thick. Immediately after cutting, we measured the thickness, moisture content, length and width of each veneer sheet. We measured the same parameters again after the drying process. The two species behaved differently, which we attribute to their distinct anatomical structure, even though both are hardwoods. Variance analyses showed that the species is the main responsible for the variation, and that beech has a higher shrinkage variation. Higher shrinkage results from the tangential cuts, compared to radial cuts.