Technological properties of medium density particleboard produced with soybean pod husk and Eucalyptus wood

Abstract

The market for wood-based panels increases annually, which along with the need for proper disposal of agribusiness wastes, justifies the search for alternative materials for new products. The objective of this research was to evaluate the effect of the use of soybean pod husks in the production of Eucalyptus MDP (Medium Density Particleboard). The panels were produced with a nominal density of 0.70 g.cm-3. The proportions used of soybean pod waste particles compared to those of Eucalyptus in the internal layer were 0, 25, 50, 75 and 100%. The adhesive used was urea-formaldehyde in the proportion of 10%, for all the layers. The pressing cycle consisted of a temperature of 160°C for a period of 15 min at a pressure of 4 MPa. To evaluate the quality of the panels produced their physical and mechanical properties were determined: apparent density; compression ratio; water absorption and thickness swelling at 2 and 24 h immersion; perpendicular traction; modulus of elasticity and modulus of rupture in static bending. The insertion of soybean pod husks in the MDP caused an increase in the dimensional instability of the panel and a decrease of the mechanical properties. The modulus of elasticity for MDP was in the range of 1842±184 to 1111±187 MPa, with 0% and 100% soybean pod husks, respectively. Comparisons with the American and Brazilian standards for particleboards were presented, showing the potential for using soybean pod husk as a natural fiber resource for production of MDP. A maximum addition of 6.4% of soybean pod husks for the production of MDP eucalyptus panels is recommended.