ABSTRACT

Wood-based composites are a popular construction material, however, the use of formaldehyde adhesives as binders in their production can have toxic health effects. In addition, the increase in agricultural industry has resulted in an increase in agricultural waste, which often goes unprocessed and disposed of improperly. To address these issues, this study focuses on the production of composite boards made from a mix of agricultural residues and plastic waste, as a way to reduce the use of formaldehyde adhesives. The study aimed to determine the feasibility of using plastic waste as a binder, and evaluated the properties of the composite boards produced, including moisture content, thickness swelling, flexural strength, tensile strength, and thermal conductivity, compared to traditional plywood products. The composite boards were made from a mix of 55%, 60%, and 70% agricultural residues (rice straw and corn cob) and 45%, 40%, and 30% plastic waste (polypropylene and polyamide). The boards were produced using heat compression at 190°C and 220°C for 12 minutes, yielding a density of 400–900 kg/m³. The results showed that increasing the amount of plastic waste in the mix led to a decrease in density, water absorption, and thickness swelling, but an improvement in bending resistance and tensile strength. The composite boards made with higher amounts of plastic waste also had lower thermal conductivity. These results provide guidelines for the use of waste materials to produce composite boards that meet standards for architectural applications.