PARAMETERS AFFECTING THE SURFACE FINISH OF PLANED SITKA SPRUCE

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