Plastifying and drying of wood and wood materials for the production of bent parts

摘要

Microwave plastifying and drying of wood and wood materials for the production of bent parts, in particular for the requirements of the furniture industry. The object of the invention is to utilise the orientation polarisation for heating the wood material to plastify it. The object is achieved with an efficiency at least 40 times greater in comparison with the conventional dampening method and less than a tenth of the time requirement for plastifying by irradiation with a microwave radiation field emitted from an aerial. The most advantageous frequencies lie between 1 and 4 GHz (wavelength between 30 and 7.5 cm). In the case of an aerial power of between 0.5 and 5 kW of the plate-shaped aerials having linear dimensions of between 10 and 50 cm, the wood material in the open or closed microwave chamber is plastified in a matter of minutes at possible temperatures of up to 400 DEG C. The plastified wood material is forced into the desired shape and is dried in the microwave radiation field. The microwave chamber, essentially a metal housing with a dielectric grating and microwave aerial(s) arranged above it, can be provided as a moisture chamber, which can be filled with and emptied of water, for moistening the wood material throughout before plastifying, or as a tunnel chamber for a plastifying and drying operation of the assembly line type.