Properties of Sandwich-Type Particleboard Panels Made from Rubberwood and Eastern Redcedar

The objective of this study was to determine some of the mechanical properties of sandwich-type particleboard manufactured from rubberwood (Hevea brasilenesis) and Eastern redcedar (Juniperus virginiana). A total of 36 panels with two density levels of 0.65 and 0.75 g/cm(3) were made using 10 percent urea-formaldehyde, a combination of 3 percent urea-formaldehyde and 10 percent cassava starch, and 10 percent cassava starch, respectively, as a binder. Three-layer panels with rubberwood fibers on the face layers and a mixture of 10 percent Eastern redcedar and 90 percent rubberwood particles in the core layer of the panels were manufactured. The highest modulus of elasticity, modulus of rupture, and internal bond strength values of 2,990, 34.72, and 1.09 MPa, respectively, were found for those panels made with 10 percent urea-formaldehyde having a density of 0.75 g/cm(3). Panels made with 10 percent starch did not have satisfactory mechanical properties and dimensional stability according to Japanese Industrial Standards. However, it seems that a mixture of a low percentage of urea-formaldehyde resin with cassava starch would be a viable alternative binder to manufacture particleboard with acceptable mechanical properties and enhanced surface quality.