EFFECT OF WOOD SPECIES USED FOR CORE LAYER ON SOME PROPERTIES OF OKUME PLYWOOD PANELS BONDED WITH MELAMINE-UREA FORMALDEHYDE (MUF) ADHESIVE

Abstract

In this study; changes in some properties of the okume plywood panels when used alder and beech veneers in their core layers were investigated. Two types of melamine-urea formaldehyde (MUF) resins having different free formaldehyde contents were used for bonding plywood panels manufactured from 2 mm thick veneers at industrial conditions. The formaldehyde emission values of plywood panels bonded with MÜF having higher free formaldehyde content were found to be higher than those of the panels bonded with other resin type. The highest formaldehyde emission value was found for the panels manufactured from okume veneers in all layers while the lowest value was determined from the panels include beech veneers in the core layer. The shear and bending strength values of the panels consisted of beech veneers in the core layer were found to be higher than those of the panels consisted of okume and alder veneers in the core layers