"Only the sky is the limit"

“Once we have started up the third Söderhamn-Eriksson USNR bandsaw next spring, we will finally have a high performance sawing line”, says Fredrik Samuelsson, production manager at the Sävar Sawmill.

High speed and high yield

As Samuelsson explains, a feed rate of 155 metres per minute is possible only after reaching the next stage of expansion. Nonetheless, when it comes to cutting precision, Norra Timber has already set new standards. The former layout, which consisted of two chipper-bandsaw units placed in a row, has been abandoned in favour of two chipper units followed by three bandsaws which do the primary and secondary cut of the prismatic wood. This has the advantage that it is not the thicker end of the log that determines how the bandsaw blade’s guides are positioned. Instead, they can be brought much closer to the actual saw kerf when separating the side boards from the log. “This and the significantly reduced vibrations increase precision in the cutting process which results in a 4% higher yield. An additional 10% yield is possible because of the thinner saw kerf of the bandsaw blade compared to that of a circular saw”, explains Samuelsson.

The first online CT scanner

That is not all, though. “Soon, we will have the first CT scanner for logs which will be directly integrated in the sawing line”, says Samuelsson referring to plans to instal a Microtec unit in the near future. The scanner will detect knots and anomalies inside the log. By turning the log appropriately, cutting precision and yield can be increased significantly. Stig Grundberg, awarded with the Schweighofer Prize and formerly working for Trätec, and Johan Oja, hired from Microtec, will be the sawmill’s in-house experts for CT-related technologies.

Low prices for wood residues as motivation

Why does a forest owners’ association, owned by some 17,000 private forest owners, make such an effort to maximise yield and added value? One reason is to make the most use of the logs provided by the members. Norra Timber’s strategic goal is to always grow more wood than what is processed in the sawmills. “As wood product manufacturers, we don’t want to depend on other suppliers to fully exploit our capacities”, confirms Samuelsson. (Note: Norra Timber operates a sawmill in Kåge complete with a sawing and planing line.) This is why it is advantageous to generate as much output from as little input as possible. An additional reason, according to Samuelsson, are the low prices for wood residues and the fact that products like these have been difficult to sell in the past five years.

In-house expertise

The sawmill relies on in-house expertise not only for its CT scanners but also when it comes to the maintenance of the bandsaw blades. Kjell-Ove Eklund and his team are responsible for sharpening, adjusting and maintaining the blades of the giant bandsaws. The tool life of one blade alone is eight hours.

After sorting it according to the respective dimensions, the sawn timber is dried in 20 batch kilns and two Valutec continuous kilns and then sorted automatically. Apart from standard products, Norra Timber offers a number of customized solutions and finished products, such as wooden floors, external and internal claddings, power and telephone poles which are exported worldwide, and Västerbotten Panels which are widely used for the construction of houses in Sweden.

In order to fully exploit the potential of the sawing line, a second stacking unit will be added. “Instead of building it next to the existing stacker, I prefer putting it on top of it. Something like this hasn’t been done before, but it offers major advantages in terms of the wood flow and the layout of our sawmill. As we don’t have the possibility to extend our factory grounds, we have to resort to building higher instead. Only the sky is the limit”, says Samuelsson with a smile.