Wood preparation process includes removing excess moisture from the timber through evaporation. What is it for?
Lumber that has undergone the drying process, get sufficient strength, less deformed, do not crack and it’s much easier to glue. Drying wood also prevents material from shrinking. Dry material is highly reliable, can be easily decorated. Wood must undergo a drying procedure, in order to receive an ideal result in terms of its quality and performance.
Firstly, wood is heated to a temperature when liquid begins to evaporate from it. The material remains for a long time period in this conditions . Most of the moisture (about 40-50% of the total mass of wood) is concentrated on the outer layers of wood, which are called sapwood.
Under the influence of high temperatures moisture actively evaporates. The moisture is still there due to very different structure of layers. Powerful internal pressure begin to rise. Steaming compensates for a temporary expansion, increased elasticity of the upper layer./p>
At the next stage, the condition of the wood normalizes; its humidity is brought to balance. After this, the cycle starts with warming up and repeats. The temperature is regulated upwards or downwards.
|Board thickness||Drying time|
|Softwood board||25 mm||9–12 hours|
|Softwood board||50 mm||18–25 hours|
|Soft hardwood board||25 mm||9–12 hours|
|Soft hardwood board||50 mm||18–25 hours|
|Hardwood board||25 mm||12–24 hours|
|Hardwood board||50 mm||24–48 hours|
The selection from plenty of drying modes is carried out on the basis of various factors: material size, seasonality, etc.
But the modes are designed for the “ideal” camera. To use them in real cameras, it requires revision, depending to the specific design features. For example, if the same mode is used in different chambers, in one of them the drying can be accelerated, as a result we obtain an increased consumption of heat carriers or a wood defect.
The technologist needs to solve such an important task: select and control the drying mode depending on the task. To do this, you need to have not only relevant knowledge, but also experience in performing such work.
Factors that must be taken into account by the technologist when choosing a drying mode:
It is important to correctly combine all these factors, thus only a specialist can perform the wood drying process.
|Type||Humidity||Price for m3|
|Edged softwood board (pine) STB1713-2007 class 2-3|
|25-44 mm||20 %||25 Eur|
|25-44 mm||below 20%||30 Eur|
|Edged softwood timber STB1713-2007 class 2-3|
|100-150 mm||20 %||30 Eur|
|100-150 mm||below 20%||35 Eur|
Termolegno CSD 50. The internal dimensions of the complex: 2 cameras of size 6500x6000x4100 mm. Fully automatic control unit allows precise control of the process.
Electronic process control equipment is a modern controller with a graphic display and a programmable menu. Standard equipment also includes: