How to enhance the drying process

Veli-Matti Lepistö

Improper drying is the cause of most damages and veneer losses in plywood production. It is the process through which quality is made and cannot be improved afterwards. During the drying process, the moisture inside wood cells is evaporated in the shortest possible time and with the minimum use of energy. It may sound simple, but production managers struggle with splits, over dried veneers, jams and stops in the process, as well as the need for re-drying and having to deal with broken veneers on a daily basis. Luckily, proper technology can make this process much more predictable.

HOW TO DRY VENEER efficiently to desired moisture and maintain quality and elastic properties for further processes? This is the question the most successful plywood and LVL producers are paying attention to. The answer lies in focusing more on the input material and combining that information to drying functions and controls in a smart way.


As every producer knows, wood material has a great deal of variation in moisture and stiffness, depending on the log size, ground, time, and place of growth.

Variation also occurs inside every block, depending on which part of the block the veneer is peeled.

As raw material properties continuously change, the drying process must also adapt accordingly. Unfortunately, most of the drying solutions on the market simply don’t have any tools for that.

When quality and efficiency matters, the right solution is an intuitive drying process that automatically adjusts the speed, temperature and moisture for a given material batch with minimized energy usage.


Taking advantage of long experience with dryers, Raute, together with Mecano, has developed accurate veneer analyzers. The most advanced mills have earlier first adapted greyscale VDA and DMA brush meter analyzers, then upgrading and ending up with the latest G5 technology.

Mecano MVA was the first analyzer that made previously impossible low moisture analyzing a reality – setting a new standard for moisture grading. Mecano MVA-G is the game changer when the highest quality, recovery and smooth operation are required. When installed in a peeling line before clipping, it offers remarkable savings by accurately separating wet and dry veneer scanning through the veneer, instead of just the surface. In addition to accurate analyzes in low moistures, MVA finds uneven moisturized zebra veneer that causes great losses in drying. When spotted already in the peeling line, zebra veneer can be dried separately in different drying conditions.

The latest addition to Raute’s product family is Metriguard Veneer Tester DME 2805, which is the industry standard in the evaluation of veneer suitability for structural uses. Together with the VDA it brings the entire grading process up to a new level by enabling even a more efficient usage of raw material.


You need valid information to be able to improve the process. Efficient drying is possible when moisture and veneer properties are properly measured and gathered data utilized in the drying line. Drying will always be one of the most challenging processes in plywood and LVL production. However, with the right knowhow and tools, challenges can be transformed into a competitive advantage!