The Effect of Fiberboard Modification on Adhesion Strength to Polyvinyl Chloride (PVC) Sheets or Eastern Beech (Fagus orientalis L.) Veneers

Abstract

The adhesion strength was evaluated for polyvinyl chloride (PVC) and Eastern beech (Fagus orientalis L.) veneers glued onto specially produced fiberboards using urea-formaldehyde (UF), polyvinyl acetate (PVAc), and polyurethane (PU) adhesives. Inorganic fillers including rock salt (NaCl), calcite (CaCO3), borax pentahydrate (Na2B44O7•5H2O), or talc (3MgO•4SiO2•H2O) were incorporated into the fiberboards at levels of 3%, 6%, and 9%. The adhesion strength of the samples was determined in accordance to Turkish Standard TS EN 311 (2005). Scanning electron microscopy (SEM) was employed to determine the structural morphology at the bonding interface of the veneers and the modified fiberboards. The results of this study indicated that veneer adhesion strength was reduced by the addition of inorganic fillers to the fiberboard. The highest adhesion strength was obtained with Eastern beech veneer that was glued using UF adhesive on the control samples without inorganic fillers. It was concluded that UF and PVAc adhesives are not suitable for bonding PVC veneers onto fiberboard surfaces.