Cleide Bourscheid’s thesis defense -Wednesday, December 13, 2023, 1:30 PM, GHK 2320-2330
You are cordially invited to attend the thesis defense of Cleide Bourscheid, PhD student in wood and bio-based materials engineering, which will take place in person on Wednesday, December 13, 2023 at 1:30 pm.
When and where?
December 13, 2023 – 1:30pm
Gene-H.-Kruger Pavilion, room 2320-2330
2425 de la Terrasse Street
Laval University, Quebec City
Deliberation: Gene-H.-Kruger Pavilion, room 2376
The members of the jury are :
Pierre Blanchet, President
Faculty of Forestry, Geography and Geomatics РUniversit̩ Laval
Roger Hernandez, Research Director
Faculty of Forestry, Geography and Geomatics РUniversit̩ Laval
Carl Blais, Research Co-Director
Faculty of Science and Engineering РUniversit̩ Laval
Ms. Isabelle Duchesne, External Reviewer
Canadian Wood Fibre Centre – Natural Resources Canada
Rémi Georges, Examiner
Faculty of Forestry, Geography and Geomatics РUniversit̩ Laval
Alexis Achim, Examiner
Faculty of Forestry, Geography and Geomatics РUniversit̩ Laval
Thesis title : Impacts of cutting speed and feed rate on the performance of a render-fragmenter
Abstract: The main objective of this study was to evaluate the effect of the cutting speed, the feed per knife and temperature condition of black spruce logs on the performance of a chipper-canter. The evaluation criteria chosen were the chip size distribution, the surface quality of the cants and the energy requirements during cutting. For this purpose, nine groups of logs were transformed at 20, 25 and 30 m/s of cutting speed, 19, 25 and 32 mm of feed per knife, and at -13 ËšC and 19 ËšC. The chip size distribution was evaluated according to their thickness, width, and length. Results showed that thinner chips were produced with the increase of the cutting speed or decrease of the feed per knife. Frozen wood produced a greater proportion of small chips and thinner chips compared to unfrozen wood. The grain angle and the proportion of knots were the main significant covariates for the chip size distribution. Moreover, the surface quality was evaluated by parameters of waviness, roughness, and torn grain. The results showed that the surface quality improved as the feed per knife decreased. Surface quality has also shown a tendency to be better with greater cutting speeds. The waviness and depth of the torn grain were similar for both frozen and unfrozen wood. The knots characteristics and the presence of left handed spiral grain contributed to reduce the quality of the surface. The mean power demanded was greater as the cutting speed or the feed per knife increased. On the other hand, the specific cutting energy increased with the increase in cutting speed and the decrease in feed per knife. For all the evaluated parameters, the energy consumption was higher for frozen wood. This thesis demonstrates that a careful choice of the cutting parameters, as well as monitoring the wood characteristics, particularly the knot properties and the presence of spiral grain, will lead to quality improvements in chip size distribution and surfaces produced by this machine. In addition, the optimization of the machining parameters to reduce waviness will also help to reduce the depth of the torn grain thus avoiding material loss. Finally, the results also will allow adjustments in the cutting parameters of chipper-canters to minimize the energy consumption of sawmills.