Surface roughness, physical, and mechanical properties of particleboard made from alang-alang and sorghum stalks

Abstract

The particleboard fabrication process has two main challenges. They are in terms of conventional adhesive application and the utilisation of wood chips as raw materials. Indonesia has numerous sources of non-wood lignocellulosic materials that can be applied to produce composite panels. Alang-alang (Imperata cylindrica) is an annual and wild plant which are widely growing in Indonesia. Sorghum (Sorghum bicolor) is a crop which currently gaining attention in Indonesia and is projected as a new staple food. The wide plantation area of Alang-alang and Sorghum, results in a high yield of agricultural by-products. This research was conducted to investigate the properties of experimental particleboard made from alang-alang and sorghum stalks, as a potential substitute for particleboard's raw material. One-layer particleboard were made with dimension 30 x 30 x 1 cm and a targeted density 0.8 g/cm3. The pressing temperatures were 150°C and 130°C, the pressing time was ten minutes, and the pressure was 15 Kgf/cm2. The adhesive used in the research was urea-formaldehyde (UF) and phenol-formaldehyde (PF) 10% based on dry particle weight. Variable factors were the ratio of alang-alang and sorghum and the adhesive type. Properties determination was conducted for its physical, mechanical and surface roughness according to JIS A 5908-2003. The actual densities of particleboard in this research were between 0.88-0.95 g/cm3. The lowest thickness swelling was 23.84%, and the least water absorption was 43.99%. The MOE values were between 9.33-25 MPa and MOE values in the range of 1130.32-2524.14 MPa. The highest Internal bond strength (IB) value was 0.44 MPa, and the best screw-holding power result was 252.3 N. The roughness average (Ra) values were 7-14.1 μm. Particleboard made of 100% sorghum with PF adhesive performs the most higher properties.