Preliminary Assessment of Sweet Chestnut and Mixed Sweet Chestnut-Poplar OSB

Abstract

Poplar Oriented Strand Board (OSB) has been produced since 2012 in Italy, and is well-established on the market. Nonetheless, some doubts have recently emerged about the raw material supply due to the trend towards reduction in plantations. Sweet chestnut is widespread in Italy, where its woodlands cover around 800,000 ha, mainly based on coppice. Partly or entirely replacing poplar with sweet chestnut would result in a new OSB with relevant perspectives for the national forest-wood sector, also interesting other European countries where sweet chestnut is widespread. The present study investigates the properties of OSB manufactured at an industrial scale with different shares of poplar and sweet chestnut wood (respectively, 50–50%, 40–60%, and 100% in weight). Density, internal bond, bending strength, modulus of elasticity and swelling were tested according to EN 300. Overall, the results indicate that sweet chestnut OSB/2 (for load-bearing use in dry conditions) can be manufactured through the process currently used for manufacturing poplar OSB, a key aspect in terms of industrial feasibility. Overall, specific adjustments in the process (concerning pressures applied, gluing system and strand cutting optimization) could make the above boards compliant with the requirements of OSB/3 (for load-bearing use in humid conditions).