Dimensional variability and drying defects affect yields during brushing processes of Eucalyptus saligna wood

Abstract

The losses due to the large number of defects of introduced wood Eucalyptus saligna during air drying were investigated in order to improve utilization yield and quality of wood planing processes. The objective was to evaluate dimensions and defects in 300 commercial pieces: boards (240 x 12 x 3 cm) and 300 tables (300 x 20 x 2 cm), which were subjected to a process of drying on the open air for more than a year. The volume of clean wood slats was obtained for average and 8,139 cm³ were reduced to 2,243 cm³, after a theoretical defect removal, ie hypothetically discounted the geometric volume of each defect. This represented a 27.5 % yield of clean wood and a loss of 73.4 % by defect removal. In tables, the average volume was 13.240 cm³ and the clean volume was calculated 4,406 cm³, an amount that represented 33.2 % least additively to calculate correction. Given this, the removal defect by brushing and squareness was processed in a sample of 15 pieces; this reached yields of 58.4 % for tablets and 51.8 % for tables, which meant losses of 41.6 and 48.2 % respectively; these losses in the brushing process were investigated showing that they affect the performance of E. saligna.