X-ray images give valuable information about the inside of wood. An imaging method developed by Technical Research Centre of Finland (VTT) can be used for sawing a tree trunk into products that are as valuable as possible.

The image scanning method improves the use of a tree that will be sawn, showing the straightness of the trunk, internal knot architecture and the best heartwood.

"Cutting a trunk into logs can be planned so that the most valuable parts are taken from the entire trunk for components that will be processed as far as possible and are suitable as parts for the wood structures of furniture, windows and doors," says research professor Arto Usenius.

Improved quality

The method is a response to demand in the wood products industry. This way of planning the sawing of a trunk for a purpose ordered by the wood products industry has spread in recent times alongside the timber that is sawn for general purposes.

"Effective cooperation by a lumber and wood-product firm means the first cut of trunk that will be felled in the forest and taken away for sawing must be planned precisely. In this way the quality of the wood products will improve and the lumber company will get a better margin per cubic metre of wood that it saws," Usenius describes.

The imaging method produces information for VTT's computer-based WoodCim® planning and control model for sawing a tree trunk. Lumber companies link this to the order-book and log storage software and the model makes a suggestion about the most profitable sawing for each log in a consignment.

Unique database

Developing a planning model that includes the X-ray imaging method for a tree trunk into an international top-grade product has been made easier by a wood raw-material database compiled over the years at VTT — the only one of its kind in the world.

"The database has recorded information about wood raw-material and its sawing processes, and the properties of products made from it and markets," Usenius says.

The planning model, which is licensed to companies by VTT, is already used by many forest-product companies in Finland. At present negotiations about the introduction of the model are under way in Europe, North and South America and Africa.

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The X-ray imaging reveals essential matters about a tree trunk.