结构用指接材制造中工艺参数对齿梳表面粗糙度的影响

指接材齿梳加工后的表面粗糙度对指接材的胶合质量具有重要影响,它受木材密度等性能指标和刀具磨损时间等加工工艺参数的影响。笔者研究了不同齿梳类型对其表面粗糙度及结构用指接材胶合性能的影响。试验用规格材材种为加拿大黑云杉(Picea mariana),分为1500f-1.4E和2250f-1.9E两个等级。齿梳长度分为12.7和28.3 mm两种。指接材试件在刀具切削磨损10和60 min后获取。试验用Veeco三维非接触式光学轮廓检测仪测量了齿梳表面粗糙度,并以平均粗糙度(Sa)和均方根梯度(Sdq)表示。此外,用力学试验机测量了指接材的弯曲弹性模量(MOR)和极限拉伸强度(UTS),以评价其胶合性能。研究结果表明:齿梳部位的Sa随着木材等级、齿梳长度和刀具磨损时间的增加而显著增加,但Sdq没有明显变化; Sa可以用作评价齿梳部位表面粗糙度的一个主要指标; 所选用材料和加工参数均能获得具有良好胶合性能的指接材; 在研究所选参数范围内,齿梳表面粗糙度对指接材的MOE和UTS没有显著影响。
Surface roughness plays an important role in determining the bonding quality of finger-joined lumber. Different material properties(e.g., density)and machining parameters(e.g., wearing time of a cutter)could result in different degrees of roughness. This study was aimed at evaluating the surface roughness of various types of finger joints and bonding quality of the finger-joined lumber. Two grades of black spruce(Picea mariana)lumber, i.e., 1500f-1.4E and 2250f-1.9E, were used. The finger joints were sampled, which had a length of 12.7 mm or 28.3 mm and were cut in the first 10 min or after 60 min in the manufacture line. The surface roughness of a finger joint was evaluated by measuring the roughness average(Sa)and the root mean square gradient(Sdq)by using a Veeco 3D non-contact optical profiler. The bending modulus of elasticity(MOE)and ultimate tensile strength(UTS)of the finger-joined lumber specimens were measured to evaluate the bonding quality. The main findings were: 1)the Sa values of specimens significantly increased with the lumber grade, finger length, and wearing time; however, the Sdq values slightly varied with the change of these factors; 2)the Sa values could be used as a primary index to evaluate the surface roughness of wood after machining process; 3)the bonding qualities of all finger-joined lumber tested were good; and 4)there was not a significant influence of Sa on the MOE and UTS of the finger-joined lumber tested