Timber customer magazine 2023

Rauma sawmill, operating round the clock is run by professional operators who monitor and fine-tune production throughout every shift to ensure the premium quality of Rauma’s sawn timber.

Arbo Lauri , an operator in the sawing team at Metsä Fibre’s Rauma pine sawmill, watches the massive logs move along the conveyor from the debarking section to the sawline. The logs now lined up for sawing are the sawmill’s largest to date, with a diameter up to 330 millimetres. “We can saw up to four premium grade planks from the heartwood of a log like this. There is also enough sapwood for narrower side boards,” says Lauri. The trunks are thoroughly examined at log reception with the aid of machine vision and artificial intelligence. The X-ray device instantly provides information about the inner quality of the trunk, including its knottiness and heartwood ratio. Every part of the log is used. The woodchips produced at the sawmill serve as raw material for pulping at the pulp mill in the same mill area, while the bark and the sawdust are used for generating power.

“It means making a pre-cut before actually sawing off the pieces. It facilitates first-class surface quality, dimensional accuracy, and high sawing speed in all log grades.” The sawline’s speed is optimised, for example according to the thickness of the log to be sawn, and the goal is to reach a maximum speed of 250 metres per minute. This is triple the speed of a conventional sawline. Lauri finds the efficiency and speed motivating. “I enjoy watching the sawline run at full speed with every- thing working smoothly. It requires continuous finetuning in the background,” he says.

Operators control quality throughout the process

Lauri’s career at Metsä Fibre began at Kyrö sawmill in 2006, and he was among the first applicants to Rauma. Lauri holds a further vocational qualification as well as a specialist vocational qualification in sawmill work. Operators at Rauma sawmill must have a keen interest in learning new things. The three-shift operation poses its own demands. The sawmill runs in three shifts seven days a week – another departure from the traditional practices of Finland’s sawmill industry. Thanks to automation, the operators now have more time for quality control. Ultimately, it is the operators’ experience and sensory quality control that ensure that sawn timber shipped worldwide from Rauma sawmill matches what the customer has ordered. “For us, quality means regular measurements. Visual inspections by the operators are also required. This applies to both the sawing result and the machines, because a blade

250 metres per minute

The area for which Lauri’s sawing team is responsible stretches from the sawmill infeed to the debarking department and the sawline. Each shift has two operators. During their shift, the team members monitor their area of responsibility in the sawmill’s control room, which is shared with operators from other teams. They also make field trips alongside control room work. The sawline is visible proof of Rauma’s role as a front- runner. At the beginning of the line, the log is rotated into the best possible position for sawing. This is the first place in the world to have introduced the dx, or pre-sawing, process.

TIMBER

27

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