Evaluation effect of kiln schedule on Warp, Twist, Bow and surface checks in Poplar Wood
M. Akhtari, M.Arefkhani
In this research, to establish a kiln-drying schedule for poplar (Populus nigra) lumber with 75 mm thickness that cut down from North Khorasan province in Iran, with three schedules T5-D2 (Forest Product Laboratory), T5-D3 and T8-D5 were adapted for drying the lumbers down to the final moisture content of 8±2%. primary dry bulb temperature each three schedules was adjusted at 49,49 and 54°C and the final dry bulb temperatures was adjusted at 71,60 and 82°C respectively. Quantity of defects including warp and surface checks of the lumber were measured before and after the drying process in each stage. In order to analysis the lumber defects for estimating the best schedule, quality control graphs were used. Results of investigation indicated that drying of poplar lumber by using of the three schedules was desired. However the first schedule (T5-D2) had better drying characteristics than the other schedules.
Keywords: kiln drying, Populus nigra, drying defects, quality control graphs