Method of drying green wood and for preventing the blue colouration of pine wood

摘要

539,675. Treating wood; proofing permeable materials. IRSA, G. I. DE. March 18, 1940, No. 5011. [Class 140] Wood is conditioned by covering it with water in a closed chamber, heating to a temperature above 100‹C., e.g. 120‹C., removing the water, introducing dry steam into the chamber and thereafter evacuating the chamber. Colouring agents may be added to the water. Cold water may be allowed to trickle over the wood during application of the vacuum. After drying, the wood may be sterilized by treatment with inert gases such as carbon dioxide or nitrogen, waterproofed by successive treatments with milk of lime and ammonia or proofed against insects by successive treatments with soft soap and copper sulphate. Alternatively the wood may be made water-repellent by adding aluminium hydroxide during the heating treatment so that aluminium oxide is formed on drying.