Rough-Mill Yield and Cutting Efficiency for No. 3A Common Lumber Compared to Other Lumber Grade Mix Options‪.‬

Abstract The percentage of low-grade material comprising the annual hardwood lumber production in the United States is increasing. As a result, finding markets for low-grade/low-value lumber has been identified as a top priority by researchers and industry associations. This research used the ROMI-RIP and ROMI-CROSS simulation programs to examine part yield, cutting efficiency, and value recovery that can be expected when No. 3A Common lumber is processed in the rough mill. Cutting bills having narrow part widths and short part lengths are the most feasible to use while processing No. 3A Common lumber. The No. 3A Common results were compared to results obtained for No. 2A Common lumber and a lumber grade mix comprised of 50 percent No. 2A Common and 50 percent No. 3A Common. Simulation results demonstrated that as the percentage of No. 3A Common lumber in a grade mix increases, part yields and cutting efficiencies decrease. For a grade mix consisting entirely of No. 2A Common lumber, part yields were between 12 and 20 percent higher than for a grade mix consisting entirely of No. 3A Common lumber. Also, the number of sawlines (a processing expense) required to produce 1,000 board feet (MBF) of parts from No. 3A Common lumber was 10 to 20 percent higher. Based on these yield and cutting efficiency results, it is estimated that a minimum lumber price difference between these two grades of approximately $217/MBF needs to exist for No. 3A Common to be a viable raw material option.