Furniture and Markets

José Ferraz

CEO Grupo Lusoverniz

Passion for woodwork…

Beautiful, natural, extraordinary, unpredictable and warm. Environmentally sustainable.

 

 

Wood is a renewable material that contributes positively to environmental conservation and climate stability, due to the fact that it absorbs and is a natural reservoir of the main greenhouse gas – carbon dioxide. Additionally, wood requires very little energy to be transformed into final products. It possesses good thermal and structural performance and is recyclable and reusable.

The large-scale use of wood in objects with a long operating life, such as in construction, and provided it comes from certified and sustained forests, contributes to the elimination of carbon dioxide whilst avoiding the use of other materials, which are highly energy-consuming in their manufacture and, consequently, crude emitters of carbon dioxide into the atmosphere.

Resulting from a prodigious vital activity, wood reflects the biological “mysteries” which determine its formation and synthesises all the singularities that personalise individuals and, wonderfully, identify them. It is, therefore, an unpredictable, surprising, living, changeable, warm and very pleasant material for the senses.

The preparation process:

Before being ready for use in furniture or carpentry, wood goes through several preparation processes.

After being cut in the forest, it is transported in logs to the sawmills, where the logs are fed into Charriot cutting machines (https://www.youtube.com/watch?v=tpoqb1DZHA8) which peel and saw the logs longitudinally, transforming them into boards and planks. Once the best boards have been chosen, they are then transported to drying centres. The bark and boards not chosen in the optimisation selection process are used as an energy source or for the manufacture of pellets.

Drying is a complex process. It starts during the tree harvesting process when moisture content is approximately 100%. To understand the mechanism of drying the wood, it is necessary to know the two ways in which water is distributed inside the freshly-sawn trunk:

– free water: is the water which fills the voids in plant cells. It is referred to as free water because it is not bonded to the wood, neither physically or chemically.

– bonding water: is the water found inside the cell walls, forming hydrogen bonds with the natural polymers which constitute it.

The free water is drained into the surrounding environment, until the wood reaches the saturation point, at which point the cell lumen is completely empty, leaving the wood with 25% to 30% humidity.

The subsequent drying, natural or forced, aims to achieve a moisture balance with the environment where it is located. Below the saturation point of the fibres, the extraction of water by mechanical processes can reach, if desired, up to 0% humidity. In reality, this never happens, except by accident, since as soon as the wood is placed in the ambient air, it immediately reaches equilibrium, and may swell until the saturation of the fibres is reached. A piece of wood placed in an environment of 60% relative humidity quickly reaches a humidity of around 12%.

There are two wood drying processes: artificial and natural. The latter is better. However, it is more expensive, as it requires large storage spaces and can take months before the wood is ready to use. Artificial drying is more precise and faster. It is carried out in closed and ventilated chambers with controlled temperature and humidity, extracting the moisture from the wood until the point of humidity equilibrium that is expected to be necessary for later use in furniture and carpentry is reached. In Portugal, it varies approximately from 8% to 12%.

Wood and wood veneer are sensitive to the environment, namely to solar radiation, rain, heat and cold.

We will talk about this characteristic in the next article.