EFFECTS OF PARTICLES THICKNESS AND VENEER REIFORCED LAYER IN THE PROPERTIES OF ORIENTED STRAND BOARDS OSB

This work evaluated the effects of particle thickness and veneer reinforced layer on the physical and mechanical properties of OSB made of Pinus taeda L. The boards were manufactured with particle thickness of 0.4, 0.7 and 1.0 mm and phenol- formaldehyde resin in the proportion of 6% of solid content. To the veneer reinforced layer was used veneer from Pinus taeda with 2.0 mm of thickness. The increase in the slenderness (length/thickness) ratio of thins particles, results in the higher values of MOE and MOR in the cross direction. The increase in the particles thickness contributed to higher values of the board internal bond. The different particles thickness did not clearly affected on the physical properties of OSB. The veneer reinforced layer results in the higher average values of MOE and MOR in the cross direction. All of the results of MOE and MOR obtained for boards with different thickness attend to minimum values required per CSA 0437 (CSA, 1993). For the internal bond, the results were satisfactory to boards manufactured with particles thickness of 0.7 and 1.0 mm. According to the results the main conclusions were: (i) The increase in the particles thickness contributed to lower values of MOE and MOR, and higher values of the board internal bond; (ii) the veneer reinforced layer increased MOE and MOR values in the cross direction.