Avaliação das propriedades físico-mecânicas de painéis de casca de arroz e adesivo tanino-formaldeído

Abstract

Rice husk, waste produced by processing of rice, has become a problem of environmental, economic and public health. As a result, this research aims to explore the potential of these underutilized resources in Brazil in the development of particleboard glued with tannin-formaldehyde. Therefore, panels were manufactured with rice husk compacted at different density (0.65, 0.95 and 1.15 g/ cm3), levels of adhesives (7, 10 and 13%) and particles types (natural and processed), totaling 54 panels. The pressing was carried in hydraulic press at 30 kgf /cm2 for 8 minutes at 1800C of temperature. The physical tests performed were moisture content, density, water absorption and thickness swelling while mechanical properties evaluated were static bending, screw withdrawal and internal bond. In general, the use of rice hulls prouced a reduction in strength when compared to those made with wood particles. All particleboard were below the minimum standards in physical and mechanical properties; only the panels with 13% resin provided minimum values required by market standards regarding dimensional stability. The results indicate that the material cannot be used in conditions requiring great structural efforts.