Investigation on the Effect of Penetration Depth and Installing Method of Screw on Withdrawal Resistance in Face and Edge of Wood Plastic Composite

In this study، the effects of penetration depth and the installing method of screw (with drill and without drill) on withdrawal resistance in face and edge of wood plastic panel were investigated. To meet this objective، the wood plastic panels from the malach choob factory with density of 1. 017gr/cm3 and 100×100×1. 4 cm3 indimension were prepared، and for withdrawal resistance test the screw with 3 mm in diameter and 2. 5 mm in length were used. Then، the samples with dimension of 2×6×1. 6 cm3 according to Iranian national standard (No: 7416) were selected and the screw joint in face and edge of panels according to variables including penetration depth of screw (6، 9 and 12 mm) and penetration type of screw (with drill and without drill) was done and the withdrawal resistance were measured on the samples. The results indicated that the withdrawal resistance of screw in wood plastic panels increases with increase of penetration depth of screw from 6 to 12 mm. Also، because of fibre compression and high density، the face of panels had higher withdrawal resistance of screw as compared with edge of them. With drilling the withdrawal resistance of screw in wood plastic panels were increased.