Influence of the Density in Binderless Particleboards Made from Sorghum

Abstract

In order to fight climate change and decouple economic growth from material use, valorization of waste will be fundamental. Sorghum is one of the most important summer crops in the world. The non-edible parts of the plant, the stalks and leaves are left over and must be disposed of. This work proposes to use sorghum waste particles as a raw material to manufacture boards and analyze the influence of its density. Particles were sprayed with 10% wt of water and placed in a hot press at 2.1 MPa and 110 °C for 30 min. Eight types of panels were produced with densities ranging from 950 kg/m3 to 1250 kg/m3. The results indicated that the water absorption (WA), modulus of rupture (MOR), modulus of elasticity (MOE) and internal bounding strength (IB) depended on the density. With higher densities, the particleboards showed better physical and mechanical behavior. This study demonstrates that it is technically possible to manufacture adhesive-free particleboards from sorghum residues that comply with European standards and can be used as boards for general applications. The use of these particleboards could be beneficial in fighting climate change and in minimizing the use of natural wood.