Abstract:
The Best Opening Face (BOF) log breakdown model was
modified to keep track of growth ring angle and growth
ring density in boards. The model was used to determine
the effects of producing rectangular rather than square
pencil stock. While an increase in volume did result,
there was also a decrease in pencil stock quality
regarding ring angle due to the lack of choice left in
orienting these pencil stock when producing slats. The
results were expressed as the percentage of change that
occurred in both volume and value recovery between
rectangular and square sawing. Overall, when considering
both pencil stock prices and ring angle factors, there
was an increase in value of 0.64% when sawing rectangles
instead of squares. However, a high standard deviation of
1.97% was linked to that average. No trends were found as
a function of log diameter, but the total value increased
slightly with an increase in log length and taper rate.
From a pencil stock seller's viewpoint, only pencil
stock prices needed to be considered. Due primarily to an increase in volume recovery, there was an average value
increase of 6.85% when sawing rectangles instead of
squares. Once again, an increasing trend was observed as
a function of log length and taper rate.
From a pencil slats producer's viewpoint, a per
board foot approach was taken. An average decrease in
value of 6.51% per board foot resulted when rectangles
were sawn instead of squares. In addition, the
distribution of pencil stock in the three ring angle
classes varied dramatically between rectangular and
square sawing. Results were sensitive to relative prices
given to pencil slats as a function of ring angle.
