World's fastest bandsaw line

Norra Timber

World’s fastest bandsaw line

LINE IS NOW OPERATIONAL, NEXT PHASE IS ANNOUNCED

This new bandsaw line, installed at a mill in northern Sweden, aims to be the fastest in the world. The first phases of this mill’s rejuvenation are complete, with the next phase – the final bandsaw in the line – to be completed in 2018.

It’s exciting to work toward achieving the fastest bandsaw line in the world, and to challenge the market with this unique solution.

Northern Forest Owners’ (Norra Timber) sawmill at Sävar, in North Sweden, recently announced it is ready to complete the transformation of its saw line. The primary breakdown process features bandsawing technology, and the secondary process includes a new edger line, all from USNR / Söderhamn Eriksson. To date, two twin Logmaster HPS bandsaws are now operational, with the third Logmaster unit to be implemented in 2018. This bandsaw line aims to be the fastest in the world when it is complete.

A view from the ChipCanter 2500 to the Logmaster bandsaw

High speed and yield

“If the third bandsaw is running next year, we will have achieved one heavy duty saw line,“ says Fredrik Samuelsson, production manager at Norra Timber’s Sävar location.

Samuelsson explained that the target of 155 m/min (500 ft/min) feed speed is expected to be achieved after the next stage of the expansion is completed. But precision cutting is already setting new standards at the mill. The earlier installation of two Logmaster HPS bandsaw units is now up and running, and the mill estimates double-digit volume increases due to improved cutting accuracy and thinner kerf sawing, as opposed to circular saw blades.

The Sävar saw line processes a wide range of timber in all dimensions, from 120 mm to 400 mm (5 to 16”), and log weight can vary from approximately 70 kg to one tonne. The average speed of the old line was 65 m/min (215 ft/min), so the target of 155 m/min for the new system is a lofty goal.

Besides increasing the line speed, a far thinner kerf is also in the works. The goal to halve the already thin saw cuts of only 3 mm to 1.5 mm is a much tougher challenge. “I have high hopes that we get down to 2 mm cuts in our new line, and then we will have halved the kerfs compared to circular saw lines, which rarely come under 4 mm,” says Stig Grundberg, sawmill manager at Sävar and technical director for Northern Forest Owners.

When fully implemented, the new bandsaw line is targeted to achieve high speed ribbon cutting, in the range of 155 m/min.

Cants are turned in preparation for processing by the second Logmaster bandsaw unit.

The line will include:

• 750E Rotary log turner

• LogPos S4 log infeed

• Two ChipCanter 2500 reducing units

• Three Logmaster HPS bandsaws

If the third bandsaw is running next year, we will have achieved one heavy duty saw line.

Saw blade monitoring: improves accuracy, safety

The new Logmaster HPS runs continuously at a band speed of 100 m/sec. (328 ft/sec.). To avoid blade rupture, it is of utmost importance to have a reliable and exact monitoring system. This is where the newly developed BMS - Bandsaw Monitoring System - comes in handy.

Like USNR / Söderhamn Eriksson’s renowned system for blade monitoring, Vision Tilt, the BMS system monitors the blade’s position on the wheel. While Vision Tilt uses a camera, the BMS system uses inductive sensors that monitor the blade, and an actuator that tilts the upper band wheel’s vertical position.

The main advantage to using inductive technology is the capability to detect cracks in the blade, even very small ones. Apart from safety risk and damage to equipment, blade ruptures create downtime. One customer indicated that the BMS investment has a very short pay-back time, as well as 100% crack detection (zero blade ruptures). He said that thanks to increased up-time in the saw line, the mill’s production has risen on average by an impressive 1.9 cubic meters (800 board feet) per hour.

The BMS’ sensors are mounted in a protective housing on the return side of the saw blade. The BMS’ detection capability is not reduced by sawdust build-up or particles in the air. BMS actively corrects the saw band’s position on the band wheel, which not only minimizes wear but also improves sawing accuracy.

Cants enter the Logmaster HPS bandsaw.

Looking to the future

We have enjoyed a good relationship of cooperation with USNR / Söderhamn Eriksson.

“Norra Timber is a very independent company. It includes all the elements of wood production and processing right through to the final product,” concludes Fredrik Samuelsson. “Next year there will be even further modernization at the Sävar plant.”

“We have enjoyed a good relationship of cooperation with USNR / Söderhamn Eriksson. It’s exciting to work toward achieving the fastest bandsaw line in the world, and to challenge the market with this unique solution,” says Stig Grundberg.

To view a video of the line in action go to: https://www.usnr.com/en/product/ logmasterhps/videos

Portions of this article were used with permission of HolzKurier magazine.