July Aug 2003
Going further with SCANNING
A new CT scanner at research organization Forintek will allow forest companies to look further inside the log and help ensure timber characteristics are best matched to lumber end-use requirements.
By Jim Stirling
Imagine, information from inside a tree. A new research tool recently introduced by Forintek Canada Corp takes imagination out of the equation. The computerized tomography (CT) scanner is a potent x-ray machine with the capability of revealing the detailed internal characteristics of hard and softwoods. It is like the diagnostic computerized axial tomography (CAT) scan used in medicine, but its capacity is 30 times stronger, making it the most powerful and versatile scanner in North America.
The CT scanner allows scientists an intimate portrait of logs up to five metres long and 90 centimetres in diameter in less than two millimetre glimpses. It works very slowly, but the resulting 2-D and 3-D images can detail the interior of the log in all its knot and moisture imperfections. The extracted information can be used for a range of purposes including relating it to stand and tree growing conditions. Forintek is a national forest products research institution, supported by its forest industry partners and the federal government.
It unveiled the new Industrial CT Imaging Centre at Forintek’s site on the University of BC campus in Vancouver in June. The centre is a joint venture with the University of Northern British Columbia, which has its main campus in Prince George. The ability to transfer images and data from Vancouver to UNBC in Prince George enhances that university’s growing forest research facilities and capabilities. The $3.3 million scanner is a larger version of one at Forintek’s eastern laboratory in Montreal.
The Vancouver scanning equipment was supplied by the US firm, Bio Imaging Research. Columbia Machine Works of Richmond, BC prepared the structure to house the unit, including a 2.3-metre thick tower of concrete to protect from radiation leakage. Suezone Chow figures the CT scanner has the potential to become a useful addition to the forest product and silvicultural research arsenal. Chow is vice-president, research and development for Canada’s largest softwood lumber producer, Canfor Corporation, based in Vancouver.
He says it’s early days yet for the scanner but has had the opportunity to use it. The scanner’s non-destructive measurement and evaluation ability allowed him to check data he’s previously gathered on the defect, structure, density and moisture content in sub-alpine fir. “The key,” says Chow, “is the interpretation of the data the scanner provides. If you don’t know how to interpret and apply the data then the data is useless,” he says. “If you can interpret and analyze it for your application or new product development, it will be good.”
Forintek has identified several broad research areas where it believes the new CT scanner’s capabilities will prove beneficial within the forest industry and forest products context. “The CT Imaging Centre is being used by Forintek scientists to characterize Canada’s forest resource,” says some of the institute’s introductory literature. “A detailed fibre quality database is being developed to provide decision support for both forestry practitioners and wood producers and will help to ensure timber characteristics are optimally matched to lumber end-use requirements.” Forintek says the scanner will add a new dimension to OPITEK, its log breakdown simulation model.
Data from the scanner will make it possible to optimize stem bucking in sawmills and improve the value and quality of saw and peeler logs. It will also help determine the effect of log conversion decisions on lumber quality and value. Forintek says the lumber drying applications of the CT scanning technology include the validation of flow measurements during drying. The scanner’s 3-D imaging abilities will also provide more insight into what precisely happens to water pockets in the log during the drying process. Moving onto composite board products, the CT scanner can detect variations in wood density, resin distribution and movement of moisture within a log, as well as accurately measure its permeability.
Forintek says applications in the value-added sector include analysis of crack development during the mechanical testing of wood products, analysis of adhesive bonds, decay detection and assessment of an array of quality factors. On the silvicultural front, creating a database on similarities and differences in internal structure and orientation of defects in trees from a range of geographical areas will indicate where the greatest values in tomorrow’s forest lie. Forintek believes the diverse abilities the Industrial CT Imaging Centre brings to the research table will help Canada’s forest industry maintain that elusive competitive edge in intense global lumber markets. But as Canfor’s Suezone Chow points out, accessing data—even the best data—is just the first step. “Information from this scanner will be available to Forintek’s member companies. It depends on the ingenuity of the company how it’s applied.”
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