Comparison of rough mill yield for white birch between a conventional and a short-log sawmill

This study explored the potential use of white birch lumber manufactured at sawmills processing short logs (no more than 8 ft. long). A database of random width and length white birch boards obtained from a conventional and a short-log sawmill was developed. To analyze the effects of lumber source, grade, cutting bill, and processing method on yield, 5,576 board feet (13.16 m3) of Selects, No.1 Common, and No.2A Common lumber were used. ROMI-RIP and ROMI-CROSS simulation software were used to model two processing methods, rip-first and crosscut-first, respectively. Four cutting orders, Furniture, Panel, USDA Easy, and USDA Tough were processed in the simulation. Processing of lumber from the conventional sawmill resulted in significantly higher furniture part yields: 8.8 percent for Selects and 10.3 percent for No 2A Common as compared to the yields derived from lumber manufactured at the short-log sawmill. These differences were explained by: 1) a shorter average length (i.e., the longer conventional-length lumber offers a greater number of part combinations); and 2) the increased presence of wane and void. However, there was little difference in yield, when comparing the No.1 Common part yields obtained from lumber from the short-log and conventional sawmills, with appropriate cutting bills. Results also indicate that crosscut-first rough milling generates, on average, a 4.2 percent higher yield than rip-first rough milling. This analysis is of interest to a value-added industry faced with resource scarcity and increasing lumber costs.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member