Abstract
In the Nordic countries, trees are typically bucked into logs using harvesters that measure only a two-dimensional diameter profile of the stem. Because the value of a log can vary significantly depending on its shape and internal defects, bucking decisions can in principle be improved by optical scanning of the three-dimensional stem shape, and detection of knots and other features inside the stem by X-ray computed tomography (CT). The objective of this study was to quantify how much the value recovery at a sawmill could be increased, if bucking decisions took advantage of additional measurement data and a sawing simulator to estimate log values. A simulation study on 1582 Scots pine stems was performed to compare bucking based on a two-dimensional diameter profile with bucking that maximises log value based on either optical scanning alone, or both optical and CT scanning. For log positioning, both the traditional “horns-down” position, and value-maximising rotation based on CT scanning were considered. The results show that bucking based on optical scanning alone can potentially increase the value of sawn timber by up to 5%, and CT scanning before bucking provides little additional value for a sawmill using a CT scanner to optimise log rotation.
Original language | English |
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Pages (from-to) | 178-187 |
Number of pages | 10 |
Journal | Wood Material Science and Engineering |
Volume | 16 |
Issue number | 3 |
Early online date | 3 Oct 2019 |
DOIs | |
Publication status | Published - May 2021 |
MoE publication type | A1 Journal article-refereed |
Keywords
- Bucking optimisation
- CT scanning
- log positioning
- sawing simulation
- value recovery