Bonding strength of some adhesives in wood materials impregnated with Imersol-Aqua

Abstract This study has been conducted to determine the effects of wood pre-treatment on bonding strength of wood materials. To this end, the test samples prepared from Oriental beech (Fagus orientalis lipsky), oak (Quercus petraea liebl.), scotch pine (Pinus sylvestris lipsky) and Toros cedar (Cedrus libani A. Rich) woods materials (based on BS EN 204) were impregnated with Imersol-Aqua (I-A) by short-term, middle-term and long-term dipping methods according to the procedure of ASTM D 1413-76 standards and directions of the manufacturer. After impregnation, shear strength tests (based on BS EN 205) were applied on both sanded and non-sanded connection surfaces jointed by poly(vinyl acetate), Klebit 303 (K303), Kleiberit 305.0, Super-Lackleim 308 (SL308) and polyurethane (PU) (diphenylmethan-4, 4′-diisocyanate) adhesives. For the samples not sanded after impregnation, the highest shear strength was obtained in beech impregnated by the short-term dipping method and bonded with K303 (11.99 N/mm2), whereas the lowest was in pine impregnated by long-term dipping and bonded with K303 (8.078 N/mm2). As for sanded samples after impregnation, the highest shear strength was obtained in beech (12.69 N/mm2) impregnated by short-term dipping and bonded with PU, whereas the lowest was in cedar (8.038) impregnated by long-term dipping with SL308. Accordingly, impregnation affected adhesive bonding strength negatively, whilst bonding surface sanding after impregnation affected adhesive bonding strength positively. To bond after the sanding process of impregnated surfaces is highly recommended to obtain high bonding strength in I-A-impregnated solid wood furniture and solid wood furniture elements.