Effect of Product Form, Compaction, Vibration and Comminution on Energywood Bulk Density

A study was performed to examine the changes in density of stacked roundwood, chips, and chunks as affected by various compaction treatments. Density of stacked roundwood bolts was tested for the effect of stacking orientation, binding of the stack ends, and species. Stacked bolt wood occupied less than 50 percent of the total rack space for all species, giving final dry bulk densities, based on total rack volume, of 159 to 293 kg/m3. Alternating butt ends in the rack increased final bulk densities by an average of approximately 40 percent. The effect was greatest for mixed, small hardwood stems. Vibration and compaction of chipped material (pine, mixed hardwood, and sycamore) resulted in final dry bulk densities of from 170 to 273 kg/m3. Vibration increased dry bulk density by an average of 20 percent, whereas compaction increased dry bulk density by about 30 percent, vibration of sycamore chunks produced a 17 percent increase.