To maximize lumber recovery, sawmills need accurate log rotation and problem-free rotation operations. Through its expanded log rotation verification studies, FPInnovations helps mills identify errors and issues that affect the value and volume recovered from logs.
Most North American sawmills use automated log turners and single – (SLI) or double -length infeed (DLI) systems that scan the logs, determine the optimal sawing solutions, and rotate and position the log for sawing and chipping. FPInnovations uses its software solution for the analysis of DLI systems. “Though we can’t use the software for the simpler SLI systems, we have a vision-based solution for them,” says researcher John White.
Most log turners have a standard deviation of over 20°, and the average rotation error is typically more than 14°. “Our analysis can quantify and identify possible sources of these deficiencies. As more mills upgrade their turners with rotation correction systems, it’s easy to assume that this verification is no longer needed. But our analysis of some upgraded machines proves otherwise, identifying issues with system performance,” explains White. “We also quantified the improvement that can be expected from the upgrade. Typically, it can only compensate for smaller rotation errors; to achieve maximum benefit, you need the best possible mechanical turner and control performance. Otherwise, value is still left on the table. FPInnovations’ work has also pushed vendors to improve their products—an indirect benefit for the industry.”
Last year, FPInnovations conducted eight studies for members, including five re-analysis studies to determine the improvements members made. “The opportunities we identified generally involved easily implemented changes to the turner optimizer parameters. Other opportunities included mechanical or control issues that can be more difficult to implement and/or correct. While the average potential value identified was 3.5%, more than $20 million in implemented value across Canada has been realized to date,” states White.
For more information, please contact John White, researcher in FPInnovations’ Machinery & Saw Performance group.