After lumber is kiln-dried it is important to keep its moisture content (MC) as close as possible to its target value during all stages of production to assure final product quality. Knowledge of climate conditions at all stages of the manufacturing process is essential to provide a good control of lumber MC. This study is the first step to provide Bolivian companies and institutions with information, currently not available, about the potential for moisture change during postdrying activities. The potential for MC gain/loss during processing and shipping was evaluated by monitoring temperature and relative humidity during lumber storage, manufacturing, and containerized transport. These values were then used to estimate the equilibrium moisture content (EMC). Readings were taken between August 2005 and March 2006 in three Bolivian manufacturing plants, located in regions representative of the different climate conditions in the country. Measurements were also taken in three containerized ocean shipments of wood products to the United States. Results show maximum/minimum differences throughout the months of the study of 3.8, 6.4, and 7.6 percent EMC for Cochabamba, Santa Cruz, and La Paz, respectively. Average differences between storage and plant conditions ranged from 0 to 3.5 percent EMC in the plants where measurements were taken and were strongly influenced by the type of construction used. Average EMC values inside cargo containers reached 3 to 4 percent above the lumber MC for the routes investigated; packaging methods were found to influence conditions inside unit loads. The differences in EMC of the materials can lead to moisture-related problems during the manufacturing process and service.
|Original language||English (US)|
|Number of pages||7|
|Journal||Forest Products Journal|
|State||Published - Jun 1 2007|