the effect of paint coating types (acid catalyzed lacquers and nitrocellulose lacquers and polyester) and nano-particles (zycosil, zycofil) on withdrawal resistance of nail and screw in wood

the potential use of nano technology for improving of withdrawal resistance of nail and screw in wood was evaluated. for this, the maintenance strength of nail and screw was measured under dry and wet conditions for poplar wood (populus nigra) coated with common paints in furniture industry and nano-particles. specimens with dimensions of 15×5×5 cm3 (l×r×t) were cut from poplar wood (populus nigra), then, nails and screws were fixed on wood specimens, with respect to the astm-d 1761 standard. afterward, specimens were separately coated with acid catalyzed lacquers and nitrocellulose lacquers and polyester paints, nano-zycosil and nano-zycofil reinforced polyester. some specimens were dried in laboratory conditions and the others, under temperature of 103±2 oc in oven, then, the maintenance strength of nail and screw was measured by a mechanical test apparatus (instron). the results revealed that the minimum maintenance strength of nail and screw is for wet specimens and the maximum is for dry ones coated with acid catalyzed lacquers and nitrocellulose lacquers paint and zycosil nano-particles. zycosil nano-particles had better performance in comparison with zycofil nano-particles. increase in the maintenance strength of nail and screw in coated specimens with nano-particles reinforced paint is due to the formed rigid surfaces and decrease of water penetration in wood.