Studies on the permeability of Norway spruce (Picea abies)

IRG/WP 2295

I Johansson, K Nordman-Edberg

It is well known that the bordered pits play a dominating role for liquid transport in softwoods. The mechanism behind pit aspiration during drying or heartwood formation seems to be well understood. The reason why the fixation of the membrane (torus) to the pit opening remains almost irreversible is, however, still unclear. A technique has been developed combining so-called "solvent exchange drying" with scanning electron microscopy. In this way the pit system can be "frozen" and the number of pits in aspiration can be determined. The technique has been used to widen the understanding of pit aspiration. It has also been used to follow pit aspiration during air drying and in connection with efforts to pit aspirated pits by different physical and chemical methods.


Keywords: PICEA ABIES; PERMEABILITY; BORDERED PITS; PECTIN; SOLVENT EXCHANGE DRYING; SEM; DRYING; FIBRE SATURATION POINT; PIT ASPIRATION

Conference: 87-05-17/22 Honey Harbour, Ontario, Canada


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