Predicting the productivity of different chipping operations

Researchers have been able to develop a model that can predict the productivity of various chippers operating in different conditions.

Chipping operations are important for the processing of material for both biomass and pulp. The time study data of over 200 chipping operations in Italy (176) and Australia (25) were used. Species processed included Eucalyptus spp., Pinus radiata, P. pinea, P. pinaster, P. nigra, Norway spruce, hybrid poplar, chestnut and other hardwoods. Chipper power (kW/hp), piece size (m3), crew size, harvesting method, species, tree part, wood condition, wood lay-out, chipping type, propulsion, feeding method, point of chipping, season, location of chip discharge, country and type of operation (biomass chip operation or pulpwood chip operation) were considered. Various brands and models of chipping machines were included.

The productivity model that was eventually developed included machine power, average piece size, location of chip discharge and type of operation as the significant factors influencing the chipper productivity. The results were confirmed against additional information on chipping operations from Italy, Australia, North America, South America, and central and northern Europe. The results showed that the model developed could be used on a global scale to predict chipper productivity. More powerful chippers resulted in high productivity, but also higher operational costs, which could result in higher unit costs. Chipping into trucks was the most the most productive option.

For a more complete account of the research, please access Southern Forests: a Journal of Forest Science, 75(3) 2013. The article is titled “A model to predict productivity of different chipping operations” and the authors were M Ghaffariyan, R Spinelli and M Brown. Source: http://www.tandfonline.com/doi/abs/10.2989/20702620.2013.816233