Water resistance of natural joint of spruce produced by linear friction welding without any treatment
Abstract
This research work showed that spruce wood can be butt welded in a short time end-grain
to-end-grain without any treatment. Wood welding has already been shown to be well
adapted to the manufacture of wood structures of larger dimensions. When pressure
increased, the welded material formed is of higher density and consequently the water
resistance improved. The welded spruce samples present a much improved water
resistance when the welding pressure was increased from 2.75 MPa to 3.75 MPa for the
same welding time of 6 s. The welded interphase in end-grain-to-end-grain butt welding
of spruce appears to occur by the formation of an interphase having the appearance of
finger-joints. This is due to the different behaviours of the late and early wood rings of
spruce during welding. This, by increasing the surface of contact, is shown to improve the
water resistance of the original butt joint.