Guasconi Federico, PhD

The wood-chipping process is affected by several factors, notably chipper settings and wood
characteristics. It is often difficult to test all of these factors in a full factorial experimental
plan, due to the large number of trials required. On the other hand, a screening design of the
experiment makes it possible to manage a large number of variables in a small number of trials.
Hence, this approach is used to test six factors, in order to optimize the productivity and
chip quality of a drum wood-chipper. These factors are: feeding speed, screen size, PTO-speed,
wood species, wood moisture content, and wood diameter. Productivity was significantly affected
by screen size, while chip quality was related to feeding speed, screen size, PTO-speed,
and wood species. The results suggest that the optimal configuration can be achieved by adjusting
feeding speed, the PTO-speed, and the wood species, as these settings maximize chip
quality. Screen size requires further analysis, as larger sizes increase productivity but reduce
quality, while the opposite is true for smaller sizes. Thus, the optimal screen size requires a
consideration of costs and benefits that may change according to the retail price of premium
and regular wood chips, and production costs.