Veneer Surface Roughness and Compressibility Pertaining to Plywood/LVL Manufacturing. Part I. Experimentation and Implication
Keywords:
Compressibility, compression, contact area, laminated veneer lumber (LVL), load, material recovery, plywood, progressive contact, roughness, strand, surface quality, trembling aspen, veneerAbstract
Extensive experiments were conducted to examine the transverse compression behavior of trembling aspen (Populus tremuloides) veneer at ambient and controlled temperature and moisture content (MC) environments, and the relationship between contact area, veneer surface roughness, and applied load. Based on the results, a novel method was developed to characterize surface roughness/quality of wood veneer in terms of its compression behavior. This method may have significant implication on both theory and practice. In theory, the general wood transverse compression theory needs to be revised to include four stages instead of the commonly defined three. The first stage, which has long been overlooked but is critically important, could be named "progressive contact." During this stage, the contact area increases nonlinearly with the load applied. It is this stage that reveals the interfacial contact of veneer-to-veneer or veneer-to-plate and the minimum veneer compression required for achieving adequate contact. With the inclusion of the first stage, the yield displacement also needs to be redefined. In practice, the method provides a fast and objective way of evaluating veneer surface roughness/quality for plywood/LVL manufacturing. Furthermore, the minimum compression required and yield displacement of wood veneer derived from its compressive load-displacement curve were found to be independent of temperature and MC, which helps benchmark material recovery in terms of veneer surface roughness/quality when manufacturing into quality plywood/LVL products. The method could also be applied to other wood composite elements such as wood strands.References
ASME Standard B46.1-2002. 2003. Surface texture (surface roughness, waviness, and lay). American Society of Mechanical Engineers, New York, NY. (Revision of ASME B46. 1-1995).nBodig, J. 1965. The effect of anatomy as the initial stress-strain relationship in transverse compression. Forest Prod. J.15(5):197-202.nEllis, S., and P. Steiner. 2002. The behavior of five wood species in compression. IAWA Journal23(2):201-211.nFaust, T. D. 1987. Real-time measurement of veneer surface roughness by image analysis. Forest Prod. J.37(6): 34-40.nFaust, T. D., and J. T. Rice. 1986. Effects of veneer surface roughness on the bond quality of southern pine plywood. Forest Prod. J.36(4):57-62.nFaust, T. D., and J. T. Rice. 1987. Effects of a variable glue application rate strategy on bond quality and resin consumption in the manufacture of southern pine plywood. Forest Prod. J.37(7/8):64-70.nFujiwara, Y., Y. Fujii, and Y. Sawada. 2004. Assessment of wood surface roughness: Comparison of tactile roughness and three dimensional parameters derived using a robust Gaussian regression filter. J. Wood Sci.50:35-40.nFukuyama, M., and T. Takemura. 1962. The effect of temperature on compressive properties perpendicular to grain of wood. Journal of the J. Japan Wood Res. Soc.8(4):170-176.nMitutoyo. 2004. SJ-400—Surface Roughness Tester. User's Manual.nNeese, J. L., J. E. Reeb, and J. W. Funck. 2004. Relating traditional surface roughness measures to gluebond quality in plywood. Forest Prod. J.54(1):67-73.nProvatas, N., and T. Uesaka. 2003. Modelling paper structure and paper-press interactions. J. Pulp Paper Sci.29(10):332-340.nSandak, J., and C. Tanaka. 2003. Evaluation of surface smoothness by laser displacement sensor I: effect of wood species. J. Wood Sci.49:305-311.nSandak, J., C. Tanaka., and T. Ohtani. 2004. Evaluation of surface smoothness by a laser displacement sensor II. Comparison of lateral effect photodiode and multielement array. J. Wood Sci.50:22-27.nWolcott, M. P., B. Kasal, F. A. Kamke, and D. A. Dillard. 1989. Testing small wood specimens in transverse compression. Wood Fiber Sci.21(3):320-329.nZhou, X., and C. Dai. 2005. Interaction of temperature and moisture content on flake compression. Proc. of the 7th Pacific Rim Bio-Based Composites Symposium. Volume II:116-125. Nanjing, P.R. China.n
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