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TiiN DP1: X-ray technology in the wood value chain

Published: 10 November 2016

To develop X-ray scanning in consultation with the timber industry:
– to utilise the potential of this technology for a more efficient utilisation of the forest raw material.
– to make it possible to deliver sawn timber with specific properties to the region’s smaller actors : producers of components, suppliers of timber products, joinery manufacturers, industrial builders etc.

Target groups

  • The timber industry in the form of sawmills able to utilise data from X-ray scanning for process optimization.
  • Minor actors in the forest products sector,
  • Joinery companies able to utilise information generated from the scanning of logs, and
  • Small service companies within the IT-sector, which can utilise the information in their work for the sawmill process in the form of simulation and process-regulating programs.


  • To increase the value of the Forest raw material, and create a stronger timber industry in the region, with expansion and an increasing degree of refinement.
  • A developed X-ray technology (discrete and tomography-based) for the timber industry, and an increased utilisation of it for industrial purposes.


For many years, LTU and SP have cooperated with machinery suppliers and the sawmill industry in developing X-ray scanning as a means of steering the sawmill process in a qualified manner.  The result is a log scanner that is now in operation in a number of sawmills. One of the first projects which was started within TräCentrum Norr (TCN) was “Improved log sorting by combining 3D and X-ray technologies”. Another project functioned also as TCN’s industrial contribution to the European project CT-Pro and this led to an industrial tomograph which is now conquering the world and which has also led to the award of  ”The Marcus Wallenberg Prize” to the persons behind the basic algorithms, technology and commercialisation.

The X-ray project has been very successful and has led to a number of valuable results, some of which are: 

  • Software which sorts timber on the basis of variables from both the 3D and the X-ray measurement frames. It has been in use in e.g. SCA Munksund since 2007  
  • Algorithms for path-length compensation which give better contrast in the X-ray images.  This functions in cross-direction X-ray without any link to the 3D-frame. It is now in operation in RemaSawco’s cross-direction X-ray.
  • Better algorithms for calculating heartwood diameter in both pine and spruce.  The measurement error has been reduced by about two-thirds and the standard deviations are currently ca. 5 mm for pine and 9 mm for spruce.
  • Better algorithms for assessing dry density, with an improvement in the coefficient of determination from about 0.3 to 0.75 for spruce and with similar results for pine.
  • The project’s contribution to the European CT-Pro project has led to the development of an industrial X-ray tomograph. Within the TCN-project, a number of different production strategies for the industrial X-ray tomograph were evaluated, and it was shown, based on the quality criteria established by both Nordic wood and INSTA 142, that it was possible to increase the value yield by 6% with rotation-optimized adjustment of the saw. 


Project leader: Johan Skog SP, deputy: Olle Hagman LTU,

Working group: LTU/SP/medlemsföretag i TCN (Träcentrum Norr) Sveaskog, Stenvalls


Olle Hagman

Hagman, Olle - Professor

Organisation: Wood Science and Engineering, Wood Science and Engineering, Department of Engineering Sciences and Mathematics
Phone: +46 (0)910 585310