EP 0197674 B1 19900523 - PROCESS FOR DENSIFYING LOW DENSITY WOODS
Title (en)
PROCESS FOR DENSIFYING LOW DENSITY WOODS
Publication
Application
Priority
CA 476650 A 19850315
Abstract (en)
[origin: EP0197674A1] Low quality, low density woods are densified to form wood products having the characteristics of high quality natural hardwoods. A green solid wood member having a high moisture content is impregnated with anhydrous ammonia to plasticize the wood into a sponge-like form saturated with water and ammonia. This plasticized wood member is placed between press plates of a cyclic press and, while maintaining the temperature of the wood below 100 DEG C, it is subjected to a plurality of low pressure compression cycles each of about 1/2 to 1 minute duration with the wood being compressed to a predetermined thickness of up to 50% less than its original thickness. It is held at the reduced thickness for a short time and released during each cycle, whereby water and ammonia are squeezed out of the wood down to a moisture content of less than about 30%. The damp wood member of reduced thickness thus obtained is then dried to obtain a kiln dried, densified solid wood product. This method may be used to densify wood planks, pre-glued laminates and thin veneers. For veneers, a simpler pressing system and higher temperatures may be used.
IPC 1-7
IPC 8 full level
B27K 5/00 (2006.01); B27K 5/06 (2006.01); B27M 1/02 (2006.01)
CPC (source: EP)
B27K 1/00 (2013.01); B27K 3/20 (2013.01); B27K 5/06 (2013.01); B27M 1/02 (2013.01)
Designated contracting state (EPC)
AT DE FR GB IT NL SE
DOCDB simple family (publication)
EP 0197674 A1 19861015; EP 0197674 B1 19900523; AT E52958 T1 19900615; CA 1236255 A 19880510; DE 3671403 D1 19900628
DOCDB simple family (application)
EP 86301862 A 19860314; AT 86301862 T 19860314; CA 476650 A 19850315; DE 3671403 T 19860314