Effect of Boron and Phosphorus Compounds on Fire and Technological Properties of Oriented Strandboard

Abstract

Effects of various fire retardant chemicals on fire and technological properties of laboratory made oriented strandboards (OSBs) were investigated. Aspen chips were used in the production of OSB panels. An exterior liquid phenol formaldehyde resin with 47 percent solid content was used as adhesive. There was no addition of any hardener and filling materials into resin in the OSB manufacturing. Boron compounds such as borax and boric acid, and phospate compounds such as monoammonium phosphate and diammonium phospahate were used as fire retardant chemicals in the OSB panels. An exterior liquid phenol formaldehyde resin was used as adhesive. The chemicals in powder form were added into the resin blender at contents of 2%, 4%, and 6% based on oven-dry wood weight. The OSB panels containing borax had the highest thickness swelling, followed by the panels containing boric acid, monoammonium phospahate, and diammonium phosphate, respectively. Increasing the content of these chemicals in the OSB resulted in greater thickness swelling. For the mechanical properties, the chemicals can be used up to oven dry particle weight of 6% in the panels at humid and dry conditions because of the fact that they met the standard values of mechanical properties given in TS EN 300 for types of OSB/3 (exterior type. Fire resistance of the panels was improved with increased chemical content in the panels.