Adaptive control of green target sizes
In Swedish sawmills,about 70％ of the total costs can be derived from raw-material costs. Hence, it is very important for sawmills to obtain the highest possible yield.The green target size is an important parameter that affects the yield. The nominal size, sawing allowance, shrinkage allowance and planer allowance add up to the green target size that is needed when sawing lumber. We have, in this work, studied whether it is possible to adaptively control the green target size by measuring log density and annual ring width with an X-ray LogScanner online. Our hypothesis was that density and growth speed will affect how much every single piece of lumber will shrink. The results show that both density and annual ring width are rather weak variables for prediction of lumber shrinkage. The variable distance to pith, i.e., where in the log cross-section a piece of lumber has been cut, has proved to be a significant variable for prediction of lumber shrinkage.The results show that the yield can be considerably improved by adapting the green target size to how far from the pith every piece of lumber is cut.
green target size sawmill density process control
Gronlund, Anders Flodin, Jens Wamming, Thomas
Lulea University of Technology Skelleftea Campus Skeria 3 SE-931 87 Skelleftea, Sweden SP-Tratek Skeria 2 SE-931 87 Skelleftea,Sweden
国际会议
19th International Wood Machining Seminar(第19届国际木材机械加工研讨会 IWMS19)
南京
英文
87-94
2009-10-21（万方平台首次上网日期，不代表论文的发表时间）