All types of wood used for manufacturing purposes first have to be dried. Drying involves the removal of excess moisture from the wood, which can be harmful. Products manufactured from undried or non-qualitatively dried wood have a much lower quality and can change dimensions or crack when operated in a dry environment, or can be attacked by wood-destroying fungi in a humid environment.
We dry wood in a few different ways, including modern convection-type aluminium construction dryers and vacuum wood dryers. The wood is dried to the desired moisture level. To achieve the highest quality of drying and the optimal result, we use computer management systems for our dryers. We can place about 2000 m3 of sawn wood (both hardwood and softwood) into our dryers at the same time.
Convection drying ovens
When using a standard convection wood drying oven, it is possible to create a modern drying environment – without heat bridges, with good thermal insulation, and which is mechanically stable and cheap. The wood is dried in a convection way in such ovens, using classical soft methods. Usually, a continuous drying method is used where the moist air extraction is regulated by a microprocessor. In this way, a low moisture level is assured along the whole length of the product during the drying process. The wood can be dried up to a 6 % residual moisture level, which can prevent wood cracking and internal tensions, irrespectively to the type and thickness of the wood. The drying process is regulated by digital microprocessors. This way of controlling the temperature and relative moisture inside the oven is reliable and easily monitored. The operator only needs about 5 minutes a day to check the data from all sensors, and to set the temperature and relative humidity inside the oven, and the moisture of the wood.
Vacuum dryers
Wood dries fast and qualitatively in a vacuum dryer, as it is dried in a low temperature and in air with a very high humidity. The drying takes place in fully hermetic ovens, from which air is extracted and the wood is slightly heated up. In air with a very low density, the moisture existing in the wood is rapidly released to the surface, where it condensates and is immediately removed from the drying oven. Here, the drying time for thin boards is decreased by almost half, and that of thick boards – by 20–30 % in comparison with dryers of other types. Vacuum dryers are preferable for those types of wood which require a long drying time in dryers of other types.
