Wood drying
AssigneeNew Zealand Forest Research Institute Limited
InventorsRobert Arthur Franich, Sheryl Suzanne Gallagher, Hendricus Wilhelmus Kroese
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Abstract
A process for removing water and solutes from the lumens of green wood, while leaving the cell walls throughout the wood uniformly fully swollen, comprises subjecting the green wood to supercritical carbon dioxide.
Claims33
A process for removing water and solutes from the lumens of green wood, which comprises subjecting green wood to supercritical carbon dioxide in cycles of pressurisation and followed by depressurisation to remove water and solutes from the cell lumens of the green wood while leaving the cell walls throughout the wood uniformly fully swollen.
A process for processing sawn lumber comprising the steps of:
- removing water from lumber having a moisture content above the fibre saturation point of the lumber by subjecting the lumber to supercritical carbon dioxide to reduce the lumber to a moisture content in the range about 30 to about 80% of the oven dry weight of the lumber while leaving the cell walls throughout the wood uniformly fully swollen;
- treating the lumber with a liquid formulation effective to increase biological durability or physical durability of the lumber;
- and then further reducing the moisture content of the lumber by air, azeotropic-, freeze-, radio frequency-, microwave-, or kiln-drying the lumber to a moisture content in the range about 12 to about 20% of the oven dry weight of the lumber.
Dependencies are inferred from the claim text.