Sawmill coefficient in the transformation of Pinus oocarpa Schiede wood in six sawmills in the departments of Nueva Segovia and Estelí, Nicaragua

Abstract

The present study was carried out in six sawmills located in the departments of Nueva Segovia and Estelí. The objectives of this study were to determine the sawmill coefficient of sawn lumber processed by sawmill and diameter category and to develop equations that allow estimating the volume of wood sawn, from the volume of wood processed and the smallest diameter of the log. A random sample of 15 logs of the Pinus oocarpa Schiede species was taken at each sawmill, for a total of 90 logs. The dimensions of the extreme diameters and their length were measured to each one of the logs to determine the volume in roll using the Smalian formula, later, they were processed to obtain common wood (boards, rulers and pottery) to these products their products were measured length, width and thickness dimensions to determine the volume of sawn lumber. To determine the sawing coefficient, the timber log volume was divided by the volume of sawn wood from each of the 90 logs. The average sawmill coefficient obtained in the six industries was 70.26 %. An analysis of variance determined that there were significant differences between the six sawmills, with yields ranging from 80 to 64 %. A correlation analysis determined that there was a positive association between the smaller diameter of the logs and the sawmill coefficient. In other words, as the diameter of the log increases, there is a greater sawing coefficient. The equation for estimating the sawn lumber volume sawn from the volume of the log roll is Y = -0.0524 + 0.8827X and the equation to predict the sawn lumber volume from the smaller diameter was Y = - 0.31 + 2.1197X. The sawmill coefficient for the six companies studied is 70.26%, equivalent to equivalent to 301.27 pt / m³ for portable sawmills with 3mm cutting width and cylindrical and good quality logs.