Abstract:
Conservation of forests is slowly shifting into a more proactive approach such
as efficient lumber conversion in sawmills. This suggests a need to explore the
use of modern sawmilling machinery in lumber conversion that produces low
residues, wastage, and hence high recovery. This study looked into the
production capacity, efficiency, and recovery rates of Cupressus lusitanica and
Pinus patula lumber from selected “WoodMizer” band saws (LT15, 20, and
40) sawmilling machinery in Kericho County, Kenya. Wood logs delivered to
each respective sawmill yard were categorized into ten diameter classes,
ranging from 10 to 59 cm for both species. Volume of four logs from each class
and species was evaluated using Huber’s formula, (1995) and converted using
through and through sawing techniques into lumber with each “WoodMizer”
band saw. Volume of the lumber pieces and residues obtained were measured.
The time taken during the conversion process was also recorded in order to
determine the efficiency and lumber production capacity of each sawmill
machines. Recovery of C. lusitanica gave average empirical values of 43%,
49%, and 53% in comparison with 39%, 34%, and 60% for P. patula using
WoodMizer LT15, LT20, and LT40 respectively. P. patula produced the most
residues at 61% and 66% compared to C. lusitanica at 57% and 51% per log
volume for LT15 and LT20 respectively but less from LT40 (47%) for C.
lusitanica and 40% for P. patula logs. WoodMizer LT40 recorded the highest
daily production capacity for both C. lusitanica and P. patula (15.9 m3/day and
16.2 m3/day) respectively. This was followed by WoodMizer LT20 at 11.2 m3/
day and 9.6 m3/day for C. lusitanica and P. patula respectively. WoodMizer
LT15 had the least production capacities of 8.8 m3/ day and 9.9 m3/ day for C.
lusitanica and P. patula respectively. These results suggest adoption of
“WoodMizer” band sawmilling in Kenya for sustainable forest resource.
