investigation on the effects of density, adhesive content and particle size on withdrawal strength of screw in particleboard made from populus (populus alba) particles

particle size, board density and adhesive content are the most important factors, influencing on physical and mechanical properties of particleboard. in this study the effects of density, adhesive content and particle size on withdrawal strength of particleboard made from populus (populus alba) particles have been studied. three levels of density including 0.65, 0.7, and 0.75 g/cm3, three levels of adhesive content including 8, 9.5, and 11% and four levels of particles size including +5, -5 +8, -8 +12, and -12 mesh were used moisture content of cake, press time, press temperature, press pressure were 12%, 5 min, 180 oc, and 35 kg/cm2 respectively. the results showed that particle size increased screw withdrawal resistance more than board density and adhesive percent, so there was a possibility to increase screw withdrawal resistance without increasing board density and adhesive percent. the highest withdrawal strength was obtained in particle board with density 0.75 g/cm3, adhesive content 11% and particle size +5 mesh.