The effect of borax in the plywood panels glueline on the mechanical properties and formaldehyde emission

In this study, the effects of borax on mechanical properties and formaldehyde emission of plywood have been investigated. Plywood panels have been produced with urea-formaldehyde (UF). The urea-formaldehyde glue formulations were mixed with various concentrations of borax pentahydrate. Two different types (poplar and beech) of 3-layer plywood were produced to determine the effect of adhesive mixture on mechanical properties and formaldehyde emission.No clear difference was observed between the shear strength and bending strength of control plywood panels and plywood panels manufactured with the glue mixture containing different amount of borax. Formaldehyde emission results demonstrated that the incorporation of borax in the glueline may decrease formaldehyde emission values.