옻나무 경사핑거접합재의 휨강도성능

The Bending Performances of Sloped Finger-Jointed Rhus verniciflua

The bending performances of sloped finger-jointed Rhus verniciflua were tested in order to improve the strength properties of finger-joint. Sloped finger-cur pieces were jointed with three kinds of adhesives (polyvinyl acetate, polyvinyl-aeryl acetate and oilic urethane resin). The slope ratios of finger joints were 0, 1.0, 1.5, and 2.0. The MOE, MOR and deflection to maximum load in bending of sloped finger-joints and solid wood specimen were measured. The results were: 1) The efficiencies of MOE to finger and sloped finger-joints to the solid wood were almost same in the three kinds of adhesives (polyvinyl acetate, polyvinyl-aeryl acetate and oilic urethane resin) and there were some effect of slope on the MOE in a sloped finger-joint for three kinds of resin adhesives. 2) There was the effect of slope on the MOR in sloped finger-joints in every kind of adhesive. The efficiencies of MOR in slope ratios of 0 and 2.0 ranged 65-79% and 85-94%, respectively. There was also a slight effect of the kinds of adhesives on the MOR. However, the efficiencies of deflection to the urethane resin adhesive were much less than those of polyvinyl acetate, polyvinyl-acryl acetate resin adhesives except the slope ratio of 0. 3) It might be impossible to estimate the bending strength of sloped finger-jointed Rhus vernicillua by using MOE. The correlation coefficiem(0.192) between MOE and MOR was very low and not significant at 5 % level.