摘要
Equilibrium moisture contents (EMC) of wood species are very necessary in the utilization of these in service. This study investigated the EMC of five lesser utilized species of Ghana and compared it with that of three European species. Sixteen randomly sampled specimens of each of the eight species (heartwood and sapwood) with dimensions 3 cm × 3 cm × 3 cm were exposed at various relative humidity conditions of 30%, 45%, 60%, 75% and 90% in a temperature and humidity-controlled climate chamber at a temperature of 25°C in accordance to German standard DIN 52182. The species are Albies alba, Fagus sylvatica and Picea abies which are European species and Amphimas pterocarpoides, Antiaris toxicaria, Canarium schweinfurthii, Celtis zenkeri and Cola gigantea are wood species from Ghana. Internal wood temperature and humidity were measured with datalogger. Samples were considered to have reached equilibrium at any given humidity when the daily weight changes were less than 0.1 mg according to German standard DIN 52183. After the last measurements of the weight changes, the samples were dried at 103°C until there was a constant weight. The five tropical hardwoods had low sorption values recorded and high sorption values for the European species and this could be attributed to differences in the microstructure of these woods.
Equilibrium moisture contents (EMC) of wood species are very necessary in the utilization of these in service. This study investigated the EMC of five lesser utilized species of Ghana and compared it with that of three European species. Sixteen randomly sampled specimens of each of the eight species (heartwood and sapwood) with dimensions 3 cm × 3 cm × 3 cm were exposed at various relative humidity conditions of 30%, 45%, 60%, 75% and 90% in a temperature and humidity-controlled climate chamber at a temperature of 25°C in accordance to German standard DIN 52182. The species are Albies alba, Fagus sylvatica and Picea abies which are European species and Amphimas pterocarpoides, Antiaris toxicaria, Canarium schweinfurthii, Celtis zenkeri and Cola gigantea are wood species from Ghana. Internal wood temperature and humidity were measured with datalogger. Samples were considered to have reached equilibrium at any given humidity when the daily weight changes were less than 0.1 mg according to German standard DIN 52183. After the last measurements of the weight changes, the samples were dried at 103°C until there was a constant weight. The five tropical hardwoods had low sorption values recorded and high sorption values for the European species and this could be attributed to differences in the microstructure of these woods.
