Bending strength enhancement of finger joints by inclusion of nanoclay in low concentrations into Urea formaldehyde adhesive

Results on the effects of using nanoclay as filler in Urea Formaldehyde (UF) adhesive to finger-joint short pieces of Melia azedarach wood are reported in this paper. Three relatively low (0.5%, 1% and 1.5%) concentrations of nanoclay containing metallic oxides were used in the study. The results are indicative of the fact that all three concentrations were able to effectively enhance the bending strengths by 22% to 58% compared to sections joined using UF with no added nano-filler. A nanoclay concentration of 1% of UF resin powder weight resulted in the highest bending strength of 50.3 N/mm2. Comparing with the MoR of clearwood sections reported in literature, the efficiency could be enhanced from 51.7% up to a range of 63% to 81.8% by addition of nanoclay. The addition of nanoclay did not result in any significant changes in the MoE values of the finger jointed sections. The study demonstrates the value addition that can be brought to finger jointed sections of M. azedarach using nanoclay in low concentrations as filler in UF to enhance the bending strength of short pieces without compromising on the stiffness.