In the timber industry, everyone knows about the high quality of log wood from northern Finland, where slow-growing pine and spruce forests characterize the landscape of Lapland.
Lea Kokkonen, owner of Tervolan Saha, is aware of the value of the raw material and its great importance for the Finnish region. “We are located in the middle of one of the most densely forested areas in the north and have the best access to log wood of excellent quality. To be able to utilize this resource and prepare our company for the future, we decided to do extensive new construction and remodeling work here at our site in Tervola. Of course, we also feel the increasingly fierce competition for raw material. Therefore, it’s crucial to proactively approach forest owners and offer them appropriate prices to secure supply over the long term.”
With the new sawmill, which includes a log yard, saw line, and green sorting line, the output of the family business will more than double in the future. “We are steadily getting closer to our target one-shift cutting capacity of around 200,000 m³ a year. We want to achieve it this year,” Kokkonen tells us.
The sawmill was designed and built to fit its intended purpose: not too big and not too small, and perfect for the local conditions and requirements.
Finnish cooperation
Happy customers: Lea Kokkonen, owner of Tervolan Saha, together with Veisto’s sales director Tuomo Kauppinen (from left) © Raphael Kerschbaumer
The investment includes many elements, starting in the log yard, where Nordautomation delivered a new high-performance system which also includes a Finnos X-ray scanner. Saw line supplier Veisto’s first contribution can be found at the log infeed in front of the sawmill. The Finnish machine manufacturer installed a 2D scanner for the re-identification of the spruce logs, which account for the majority of the processed log wood, and the remaining pine logs. The scanner detects the geometry of the logs before they are turned by a rotating device if necessary. The latter is there to ensure that the logs always pass through the debarker and the saw line with the top end first. Veisto’s line is designed for log diameters of 14 to a maximum of 38 cm. Due to the harsh growing conditions in Lapland, the average diameter does not exceed 18 cm.
Individual adjustment of performance
Full control of log rotation: Whether at the beginning, with the debarked logs … © Raphael Kerschbaumer
At the beginning of the high-performance Hewsaw SL250 2.2 saw line, a scanner precisely measures each log and creates a digital duplicate of it. “This step determines the cutting pattern and thus the yield from the logs. We take the curvature, the quality of the log wood and the direction of the wood fibers into account. Based on these data, we can position each log so that it can be cut in a way that is optimized both in terms of yield and quantity,” Tuomo Kauppinen, sales manager at Veisto, explains.
… or at the end of the saw line, when the log is chipped on four sides (below) © Raphael Kerschbaumer
Behind the scanner, the logs pass through the four-sided chipper unit at a speed of up to 130 m/min. With the chipper unit, two sideboards can be produced as well. “The feed speed of the line and the installed units are tailored to the requirements and output of the sawmill. This way, the customer gets exactly what they need and can save valuable resources,” Kauppinen emphasizes.
Scanner with many advantages
The log without the sideboards is then re-measured all around. “We need this additional scanner for quality reasons. After the first processing step, many logs deform slightly due to internal tensions. To make sure that this doesn’t have a negative effect on sideboard yield, we re-measure the ‘core log’ and adjust the cutting pattern in real time if necessary. Especially fresh and fast grown beetle-damaged wood from Central Europe sometimes shows significant deviations and deformations that can have a significant negative impact on yield,” the experienced industry expert Kauppinen explains. “Another advantage of this additional scanner is that it recognizes the direction of the wood fibers determined by the first scanner, thus allowing immediate conclusions about any inaccuracies inside the chipper unit. This is a great advantage in the maintenance of older machines in particular,” he adds.
Taking care of everything
The final circular saw unit rip-cuts the main lumber before the boards are transported towards the green sorting line © Raphael Kerschbaumer
Veisto not only supplies the machines but also takes care of all interfaces, safety and hydraulic systems, and the entire plant control, which was designed and programmed by the company’s mechanical engineers. “What Veisto delivered is an absolute top-quality product from start to finish. We can control the entire saw line from a central control room with just one employee – that’s quite impressive,” a satisfied Kokkonen comments and adds: “The collaboration with Veisto was excellent from the first meetings, allowing us to ramp up the sawmill and start production as planned.”
