Researches on influence of wood sanding direction on wood gluing

AbstractThe wood surface quality is most determined by the way in which it has been processed before and by the tools used for this purpose. Machining has its effect primarily on the structural shape of the surface formed after the tool–wood contact and also on the roughness of the surface obtained after a specific process. In most cases, wood surfaces of elements which are materials or semi-finished products used for further processes, including gluing or painting, are sanded with sandpaper of various grit sizes on belt sanders. This causes the structure formed on the wood surface to be unidirectional. No information is available in the literature on the influence of the direction of the post-processing structure of the glued surfaces on the gluing process. Therefore, this was the subject of this research study. Two kinds of wood glues were used, and three gluing pressures were applied. Contrary to what was expected, the effect of the mutual position of post sanding surface structures during the gluing operation on the amount of glue in the connection turned out to be of small significance. In an extreme case, the difference of a necessary minimum amount of glue was 15.1% for the same type of connection and a different position of the glued surfaces against each other. However, the kind of the glue being used and the gluing pressure have been found to have a significant effect on its amount necessary to produce a good connection.