Timber seasoning and density characterstics of Cordia alliodora Cham. (Boraginaceae) grown in Ethiopia and its potential uses

Abstract

The knowledge on basic wood properties including timber seasoning, density and technologies of utilization would determine rational use and large-scale development of each timber species. A study was conducted on home-grown Cordia alliodora timber with the main objective of determining some important seasoning and density characterstics that indicate its timber quality to decide its proper utilization. The experiments were conducted using oven/microwave, air and kiln seasoning methods. Harvested logs were sawn while green and lumber stacked using stickers with three replications and seasoned from green (initial) moisture content (MC) to about 12% MC. The mean initial MC was 54.5% and density 550 kg m^-3. Results revealed that there were significant differences (P<0.01) between the seasoning methods, among shrinkage characteristics, and density values at different MC levels. Mean and range of final air seasoning MC of the species were 12.38% ± 2.7 and 11.93-12.75%, respectively while those of kiln seasoned batches were 14.24% ± 2.1 and 10.48-17.42%, respectively. Mean final MC of the seasoned timber for both seasoning methods was 13.31%. Cordia alliodora showed very rapid air (35 days) and kiln (2.2 days) seasoning rates. The mean density at 12% MC was 390 kg m^-3. Shrinkage values of the timber at oven dry (0%) MC compared at 12% MC increased by about 1.7 times. Slight seasoning defects such as cup, bow, twist, end split and checks were observed. In general, the species revealed good timber properties and qualities. Therefore, the species has to be grown and well managed, timber properly seasoned to less than 20% MC, with a method that can help increase quality, minimize seasoning defects and shrinkage characteristics. Consequently, timber has to be properly handled and rationally utilized at specified MC and density for intended construction and furniture purposes.

Keywords/phrases: Moisture content, Rate and defects, Seasoning methods, Shrinkage characteristics, Uses

Ethiop. J. Biol. Sci., 10(2): 185-206, 2011