PARAMETERS AFFECTING THE SURFACE FINISH OF PLANED SITKA SPRUCE

The influence and relative significance of the various silvicultural and machine surface planing parameters in the production of good quality timber surface finishes on Sitka spruce is investigated. Data analysis was carried out using linear multiple-regression techniques. Results are presented in the form of regression charts and scatter plots. Feed speed, moisture content, and rake angle variables have been found to be important predictors of the quality of machine-planed timber. In particular, setting the feed speed to 10 m/min. results in a good-quality finish. Two distinct areas that demand separate scrutiny have been identified on the timber sample boards, the clearwood area and the knotwood area.