Investigation of the Best Joint Type for Combining of the Finger Jointed Timber Panel in Board Production

Abstract

AbstractWaste sawn timber material in furniture factories and short length of sawn timber are serious problems in timber industry. To further suggest ways to minimize the waste, by applying a jointing system, this paper utilizes the finger-jointed techniques. Using this method, waste timber planks, trimmings and edgings can be used as finger-jointed boards and furniture in sustainable way. Finger joint technique is also used to eliminate wood defects which weaken the strength of sawn wood planks. Finger joint technology is used in structural and non-structural applications. Furniture mainly belongs to non-structural category. This study was conducted to investigate the best joint type for combining of the finger-jointed timber panel in board production. Shear test was done to determine the most suitable joint type which could be employed in combining two finger-jointed timber panels. Shear test was performed for Pine—Pinus carebaea (soft wood) and Teak—Tectona grandis (Hard wood) timber types. Clear specimens, butt-jointed and tongue and groove were tested in the shearing apparatus. Eight test specimens of each timber specimens were used to obtain shear strength perpendicular to grains with 0.5 mm/min loading rate was applied using a Universal Testing Machine. Shear strength of Teak specimens with tongue and groove is higher than Teak specimens with butt joint, because bonding area of the tongue and groove specimens is higher than bonding area of the butt-jointed specimens. Specimen part with tongue of Pine is weaker than corresponding part of butt-jointed Pine specimen due to small cross-sectional area of tongue. So, Shear strength of Pine specimen with butt joint is greater than Pine specimen with tongue and groove.KeywordsFinger jointJoint typesbutt jointTongue and grooveShear test