Optimization of Welding Frictional Parameters by Inserting the Dowels of Beech in Douglas-Fir Wood Substrate

Ibrahim Busuladzic, Izet Horman, Ninoslav Beljak, Esed Azemovic

The wood welding technique has been developed as a new technique for joining wooden parts without the use of adhesives, and with the help of heat developing due to friction and pressure on the joint.  The friction may be realized by vibration or rotation. Wood welding is a process in which chemical-physical reactions occur. During the welding process, the surface layers in the wood elements (lignin) were broken into mutual contact, which was initiated because of the influence of pressure and heat which is most often achieved under the influence of the friction of the elements we are interfering with. The paper presents the results of our own exploration of the impact of the penetration of the beech dowels into the substrate of Douglas/fir on the basis of pulling force. Within the experimental investigation we have observed differences between the direction of penetration of the dowel in the hole with (and without) changing the profile of the pre-drilled hole for insertion and the impact of the bond withdrawal strength in relation to the angle between axes of penetration and the line of tree rings.