Abstract: A hydrophobisation composition, which includes a hydrophobisation extract obtained by extracting outer bark of birch in an organic and/or polar solvent and which includes at least 30 weight-% betulinol. Also disclosed is a method for hydrophobisation of a surface, which includes steps of applying a layer of hydrophobisation composition containing betulinol on a surface of a substrate, and drying and heat-treating the layer of hydrophobisation composition. A substrate having a surface which is hydrophobised by using the method is also disclosed.

Abstract: A hydrophobisation composition, which includes a hydrophobisation extract obtained by extracting outer bark of birch in an organic and/or polar solvent and which includes at least 30 weight-% betulinol. Also disclosed is a method for hydrophobisation of a surface, which includes steps of applying a layer of hydrophobisation composition containing betulinol on a surface of a substrate, and drying and heat-treating the layer of hydrophobisation composition. A substrate having a surface which is hydrophobised by using the method is also disclosed.

Abstract: A method for recovery of branch knot wood and/or normal wood from oversize chips in which the oversize chips are ground to splinter, which then is dried and mixed with water, and then the sedimented splinter containing high concentrations of extractive substances and having a high specific weight is recovered and extracted in order to recover valuable extractive substances, particularly lignans. The lighter splinter floating up to the water surface is recovered in order to recover normal wood material for the pulp production.