Machining characteristics of Gmelina Arborea grown in Ghana

Abstract

Utilisation of lesser known species (LKS) or lesser used species (LUS) has become a necessity in the face of dwindling prime timber species. This study therefore contributes to utilization of LUS by investigating and determining Machining Characteristics of Gmelina arborea grown in Ghana. Four trees were obtained from G. arborea plantations in two different locations: Daboase in the Western region and Abofour in the Ashanti region of Ghana. Each tree was sawn into three sections; top, middle and butt. Planing, turning, shaping and sanding tests were conducted on each of the sections. For the planing test, a constant cutting angle of 30° was employed in combination with feed speeds 6m/min, 9m/min and14m/min. Turning test employed spindle speeds of 1000rpm, 1850rpm and 2500rpm.Shaping test was conducted using three different spindle speeds of 4500rpm, 6000rpm and 10000rpm.The sanding test employed three different grit sizes, P80, P100 and P120. Results show that the least feed speed of 6m/min was found to produce the highest rates of acceptable grades for wood specimens from both locations. The spindle speed recording the highest rate of acceptable grades for Daboase wood samples was 1850rpm but 2500rpm for wood samples from Abofour. It was also observed that, 10000rpm produced highest rates of acceptable grades for shaping wood samples from both locations. For wood samples from Daboase, grit size of P100 produced the highest rate of acceptable grades. However, Abofour wood samples produced highest percentage of acceptable grade at grit size P120.The good machining characteristics of Gmelina arboreaas indicated by this study makes it recommendable for the furniture industry.