Drying
The veneer drying process is the production stage in which thin wood sheets coming out of the peeling phase are dried under controlled conditions and brought to the optimum moisture level. Drying is a decisive stage in terms of the quality, durability, and bonding strength of the final product.
Why Is Drying Necessary?
Fresh veneer sheets coming out of the peeling process contain high amounts of moisture. Although this moisture content varies depending on the wood species and season, it generally exceeds fifty percent. Veneer sheets with high moisture content cannot be directly subjected to gluing and pressing; because excess moisture prevents the adhesive from penetrating properly, moisture that evaporates during pressing causes blistering and delamination in the panel, and the dimensional stability of the final plywood panel is compromised. Through the drying process, the moisture content is reduced to between 6% and 8%, preparing the veneer sheets for the gluing stage. In line with customer requirements, specific custom moisture values in the range of 4%–15% can also be achieved.
Operating Principle of Drying Ovens
At Alesta Naturel facilities, the drying process is carried out in continuous-flow (roller) drying ovens. Veneer sheets are passed through the oven via a belt system. The temperature, airflow, and passage speed inside the oven are precisely adjusted according to the wood species and veneer thickness. While hot air rapidly removes moisture from the veneer surface, moisture and temperature are continuously monitored to prevent over-drying.
The Importance of Drying Parameters
Each wood species requires a different drying temperature and duration. Beech veneer requires a longer drying time due to its denser structure, while poplar veneer dries more quickly. If the drying temperature is too high, cracking and color changes may occur on the veneer surface. If it remains too low, sufficient moisture cannot be removed and bonding quality decreases. For this reason, optimum drying parameters are carefully determined and applied for each batch.
Post-Drying Quality Control
After the drying process, veneer sheets are checked with moisture measuring devices. Sheets outside the target moisture range are returned for re-drying or set aside. Veneer sheets that pass quality control are sorted and prepared for the gluing and pressing stage.
As Alesta Naturel, we carry out the drying process to European quality standards at both our Ukraine and Sakarya Akyazı facilities. Thanks to correct drying parameters, the plywood and wood panel products we manufacture offer high bonding strength and long-lasting quality. In line with customer requirements, we can work at custom moisture values in the 4%–15% range.
For detailed information about our drying process and products, you can contact our team
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Fresh veneer sheets have a moisture content exceeding fifty percent; drying reduces this to 6–8%.
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In continuous-flow roller ovens, temperature and airflow are precisely adjusted according to wood species.
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Excessive drying causes cracking on the veneer surface; moisture and temperature are continuously monitored.
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After drying, each sheet is checked with moisture measuring devices and prepared for gluing.
F.A.Q
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What is the target moisture level in veneer drying?
Before proceeding to the gluing and pressing stage, the moisture content of veneer sheets must be between 6% and 8%. Sheets outside this range negatively affect bonding quality and the durability of the final panel
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Does the drying duration vary by wood species?
Yes, since the density and moisture content of each wood species differ, the drying duration and temperature also vary. Hardwoods such as beech require a longer drying time, while softwoods such as poplar can dry in as little as 20 minutes.
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What is the effect of improper drying on plywood quality?
In the case of insufficient drying, the adhesive cannot penetrate properly, and moisture evaporating during pressing causes blistering and delamination in the panel. With excessive drying, cracking and color changes appear on the veneer surface and bonding strength decreases.
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How does Alesta Naturel control drying quality?
After each drying batch, veneer sheets are checked with moisture measuring devices. Sheets outside the target moisture range are returned for reprocessing. Oven temperature, airflow, and passage speed are continuously monitored to ensure optimum drying conditions.
