Qualidade de painéis aglomerados produzidos com mistura de madeiras de quatro espécies florestais

Abstract

The objective of this work was to investigate the quality of particleboards made with wood of Pinus taeda, Eucalyptus saligna, Mimosa scabrella and Hovenia dulcis and mixtures in different proportions and two board compositions. The boards were produced in proportions of the 100% (Pinus taeda), 50-50%, 50-25-25% and 25-25-25-25% for homogeneous boards and 50-50% and 100% (Pinus taeda) for the multilayer boards. The adhesive used was based on urea-formaldehyde and the nominal density was 0.65 g/cm³. We evaluated the properties of water absorption, thickness swelling, static bending, internal bond and screw withdrawal. The analyzes allowed to evaluating the use of different species wood mixtures in particleboards. The results were also compared the requirements of applicable ANSI A 208.1, DIN 68 761 (1), (3) - 1967 and Wood handbook (USDA). The values of static bending, internal bond and screw withdrawal increased with increasing proportion of Pinus taeda and Hovenia dulcis and decreased with increasing proportion of Mimosa scabrella and Eucalyptus saligna. For the properties of water absorption and thickness swelling, the wood of Eucalyptus saligna presented higher values in relation to Pinus taeda. The wood of Mimosa scabrella has similarity to the Hovenia dulcis wood, having advantage to this last species. Therefore, for the mechanical properties, it can be concluded that better species were the Pinus taeda and Hovenia dulcis and the physical properties, Eucalyptus saligna and Hovenia dulcis. Regarding the composition, multilayer boards, mostly showed themselves superior to homogeneous boards.