Drying logs of Eucalyptus urograndis clones in a solar greenhouse

Abstract

Drying is an important stage in the wood industrialization process, with the purpose of improving the quality of the material. However, it is an expensive process, and there is a need to reduce its costs by using methods that require less investment. Thus, the objectives of this study were to evaluate the efficiency of a solar drying oven for drying Eucalyptus urograndis clone logs installed in the municipality of Macaíba, state of Rio Grande do Norte, in order to check whether the region is suitable for this practice; and ii) to evaluate the influence of different log diameter classes in the drying process. 1.50m logs were sectioned and separated according to four diametric classes. They were then weighed and placed in a solar oven, with daily measurements of air temperature and relative humidity and biweekly weighings during the observation period until they reached the fiber saturation point. The data were submitted to regression analysis, applying the variable selection procedure. At 35 days, all logs had already reached the PSF. However, the diameter measurements did not significantly affect the drying process, which proved to be efficient when compared to conventional and natural methods. Therefore, the solar kiln drying of logs becomes a viable method for the region.