Properties evaluation by thickness and type of oriented strand boards manufactured in continuous press line

Abstract

Oriented strand boards (OSB) are widely used in construction replacing plywood. There are four types of boards (OSB/1, OSB/2, OSB/3, OSB/4) carried out depending on the conditions of uses. The present research aimed to evaluate the physical and mechanical performance of these types of boards, with 10 mm, 11 mm, 18 mm and 22 mm thicknesses. The boards were industrially manufactured using the continue press line. The results showed that the compression grade increased with decreasing of the wood strands densities, from 1.3 (OSB/1) to 1.1 (OSB/3). Thickness swelling values were lower for OSB/3 and OSB/2 with 35% and 14%, when compared to OSB/1. For these boards a slight increase in adhesive content and a lower speed of pressing line was set considering that they are designated for the exterior use. An increase in density with about 7.6% led to an increase with about 19% of modulus of rupture (MOR), when compare OSB 10 mm with OSB 22 mm. Improvements with 27% to 22% MOR and 13% to 10% modulus of elasticity (MOE) in case of OSB/3 and OSB/2 compared to OSB/1 were found. Internal bond (IB) values were with about 32% higher for OSB/3 than those reached by OSB/1 and the thinner boards registered 25% higher IB values even after boiling test, compared to the thicker ones.