WOOD DRYING: WHY IT IS IMPORTANT ?
Whether it is a wooden piece of furniture or a shelf for the kitchen or bathroom, it is always essential to be able to count on wooden boards subjected to a drying process. This treatment in fact serves to eliminate the excessive amount of water present in the trunk of the plant, restoring materials that are more stable over time, easier to work with and not subject to bending, cracks or alterations due to fungal attacks.
In fact, when the tree is cut down, depending on the species and the environment in which it has grown, it can contain a percentage of humidity ranging from 50% to 300%. Once cut, it begins to release the water contained in the cellular lumens. This results in a loss of weight but not a decrease in volume. Only when the moisture content percentage reaches around 30% do we see the saturation point of the cell walls, or the moment in which any further loss of moisture also gives rise to the decrease in volume (or shrinkage of the wood).
Only after the amount of excess water in the cell walls has been eliminated is it possible to have the security of a raw material suitable for processing for the production of interior furnishings.
METHODS OF DRYING WOOD
The wood drying can take place both with the natural method and with the artificial one. Natural wood drying involves stacking the boards in a sheltered, dry and sufficiently ventilated environment. It does not require the use of any type of machinery: the humidity rate is progressively reduced thanks to the warm air currents and then continues with the migration of humidity from the center towards the outside of the table. The natural drying system requires a very long time (it can take many years before the boards can be processed).
The other method of preparing the boards for processing is the artificial drying of the wood. During this process the pieces of wood are placed in special ventilated and dry chambers, called dryers. The controls of the temperature and of all the conditions necessary for a good seasoning of the wood are carried out by means of electric climatic systems and the timber is completely dried after just 3/5 days of treatment. As in the case of natural seasoning, even with the artificial process, timber is obtained in optimal conditions to be processed, without causing stress to the material.
However, it should be noted that neither natural seasoning nor artificial drying will completely eliminate moisture from the wood. A percentage of residual humidity will always remain to guarantee a perfect dynamic balance with the thermo-hygrometric conditions of the environment. The woody material in fact absorbs and releases humidity from the space in which it is placed, until a perfect balance is reached between the two states.
If, after being subjected to artificial drying processes, the wood is stored outdoors, it tends to reabsorb moisture, which however stops at the cavity of the woody cell without reaching the cell wall. This involves, once transferred to a sheltered and dry place, the restoration of optimal humidity levels in a short time.