OPERATIONAL EFFICIENCY IN SAWING Pinus USING CUTING MODELS IN SMALL SCALE SAWMILL

Abstract

This research evaluated a methodology of cutting logs that involves both their classification and the establishment of cutting models for different diametrical classes. The software MaxiTora was employed aiming the optimization of cutting logs. A total of 80 logs of Pinus sp had been selected with diameter that varied from 24 cm to 33 cm, gathering four diametrical classes with 20 logs each. In each diametrical class, the logs had been separate in two lots with 10 units, where the first lot was submitted to conventional cutting and the second lot was submitted to the programmed cutting. For each log the effective time of cut was recorded until the last lumber piece was edged. For the conventional cutting system, the efficiency reached from the same cutting system varied from 9.71 to 11.22 m3/operator.day and the general average corresponded to 10.18 m3/operator/day. In the programmed cutting system, the efficiency reached through the same cutting system varied from 7.78 to 8.99 m3/operator.day, while the general average corresponded the 8.07 m3/operator.day. The general average efficiency achieved in the programmed sawing process was smaller in relation to general average efficiency obtained with conventional sawing process. The sawing efficiency achieved in the programmed sawing process was reduced due to the lack of experience of machine operators.