METHOD AND DEVICE FOR PRODUCTION OF MODIFIED WOOD Russian patent published in 2000 - IPC

FIELD: wood-working industry, in particular, technology and equipment for production of modified wood, applicable in production of bearing material based on wood. SUBSTANCE: blank of wood with fibres arranged perpendicularly to the longitudinal axis in width, whose dimensions (along fibres) are equal to or less than the wave- length of electromagnetic SHF energy, with a water content of 15 to 17%, is placed in a box-section container with open ends on the sides along the container length. The container is put in a mould under a press, where the wood gets moulded. Then, the container is taken out of the mould with moulded wood and installed in a chamber with a system of blowing with hot air at a temperature of 105 to 115 C between two adjusting horns so that the larger bases of the horns would be conjugated with the open end walls of the container. The generator is switched on, and the blank is additionally influenced by a pulse flux of electromagnetic SHF energy directed towards the end of the blank along the wood fibres, with a power density of 0.2-0.3 W/cu.cm and density of flux of electromagnetic energy within 2.5 to 3.5 W/sq.cm. In the first stage the blank is heated to a temperature of 105 to 115 C by 4-5 pulses of electromagnetic energy with a duration of 55 to 65 s, spacing within 115 to 125 s, and in the second stage the blank is subjected to heat treatment by 30 to 40 pulses with a duration of 25 to 35 s, spacing within 120 to 180 s. The feed of hot air and removal of steam are accomplished through the holes in the horn walls, adjoining the container, with a diameter of at least 0.1 of the generator wavelength. Heat treatment is conducted to a final water content in the wood blanks within 4 to 6% and full stabilization of the shapes and dimensions. EFFECT: reduced power consumption, time of the process of production of modified wood, enhanced physico-chemical properties of it. 4 cl, 2 dwg, 2 tbl