Addition of Boron Based Compound in the LVL Glueline: Effect on the Mechanical Properties and the Leaching of Boron

Abstract

Summary This study aims at the optimization of the durability of Laminated Veneer Lumber (LVL) panels by adding borates to the gluing formulation. Poplar veneers measuring 2.6 mm thickness were used for the manufacture of LVL by Isoroy, a French company located in Lisieux. The melamine-urea-formaldehyde (M.U.F.) glue formulations were mixed with various concentrations of boric acid. A 0.8% retention of boron was measured in the LVL panel after intensive water leaching. The mechanical properties of finished LVL panels and their bonding strength properties were evaluated. The influence of the glue bonding on leaching was also evaluated. The amount of boron in LVL was measured by spectrocolorimetry using the CIELAB system. Results demonstrated that the incorporation of boron in the glueline may improve LVL durability.