The effect of hydraulic linear positioners on the production efficiency of a hardwood sawmill

Abstract

The hardwood sawmill industry is faced with a decreasing availability of high quality timber, and declining log quality. Ways to improve the technology are needed so that this lower quality resource can be better utilized. The hydraulic linear positioner is one such new technology.

The objective of this research is to quantitatively determine the impact of hydraulic linear positioners on the production efficiency of hardwood sawmills by an analysis of: 1) lumber grade yields; 2) log value; 3) sawing time; and 4) sawing variation attributed to the linear positioners, using Factory Grade No. 2 red oak logs sawn into lumber by full-infinite taper and conventional sawing patterns.

The results of this study indicate:

1) Hydraulic linear positioners in a hardwood sawmill can improve the production efficiency by a little over one percent (the positioners alone), and by up to 11 percent when including the contribution of the hardware and software with the positioners.

2) Selecting the opening face and using the full-infinite taper setout capabilities of the positioners did not improve the lumber grade yield from the logs used in this study.

3) Opening face selection and taper setout increase sawing time and thereby reduce the log value when based upon a $/log/operating minute. Such practices can reduce the production efficiency by up to $17 per log per operating minute.