Adhesive Penetration in Wood—a Review
Keywords:Bonding, resin penetration, microscopy
AbstractAdhesive bond performance between wood elements is presumed to be significantly influenced by the degree of penetration of the adhesive into the porous network of interconnected cells. Research on the bondline performance has been conducted through microscopic examination and associated techniques in an effort to establish relationships with the bond performance. The purpose of this communication is to provide a technical review of research on adhesive penetration, and to promote the efficient use of adhesives in regard to cost and performance, particularly in reference to the manufacture of wood-based composites. Assessment techniques, influence on bond performance, and distinctive characteristics of common adhesives used for the wood-based composites industry were the main focus of this review. Variability between wood species, the wide variety of adhesive application and curing processes, and the many types of adhesive chemistries and formulations make sweeping generalities difficult. However, troubleshooting bonding problems and designing new adhesive systems and processes may be facilitated by understanding the fundamentals of adhesive penetration.
Bolton, A. J., J. M. Domwppdoe, and D. A. Davies. 1988. The validity of the use of SEM/EDAX as a tool for the detection of UF resin penetration into wood cell walls in particleboards. Wood Sci. Technol.22:345-356.nBrady, D. E. and F. A. Kamke. 1988. Effect of hot-pressing parameters on resin penetration. Forest Prod. J.38(11/12):63-68.nBuckley, C. J., C. Phanopoulos, N. Khaleque, A. Engleln, M. E. J. Holwill, and A. G. Michette. 2002. Examination of the penetration of polymeric di-phenyl-di-isocyanate (pMDI) into wood structure using chemical-state x-ray microscopy. Holzforschung56(2):215-222.nChristiansen, A. W. 1990. How overdrying wood reduces its bonding to phenol-formaldehyde adhesives: A critical review of the literature, Part I. Physical responses. Wood Fiber Sci.22(4):441-459.nChristiansen, A. W. 1991. How overdrying wood reduces its bonding to phenol-formaldehyde adhesives: A critical review of the literature, Part II. Chemical reactions. Wood Fiber Sci.23(1):69-84.nCollett, B. M. 1970. Scanning electron microscopy: A review and report of research in wood science. Wood Fiber, 2(2):113-133.nCollett, B. M. 1972. A review of surface and interfacial adhesion in wood science and related fields. Wood Sci. Technol.6:1-42.nConrad, M. P. C., G. D. Smith, and G. Fernlund. 2004. Fracture of wood composites and wood-adhesive joints: A comparative review. Wood Fiber Sci.36(1):26-39.nDougal, E. F., J. D. Wellons, R. L. Krahmer, and P. Kanarek. 1980. Glueline characteristics and bond durability of southeast Asian species after solvent extraction and planning of veneers. Forest Prod. J.30(7):48-53.nEbewele, R. O., B. H. River, and J. A. Koutsky. 1986. Relationship between phenolic adhesive chemistry and adhesive joint performance: Effect of filler type on fracture energy. J. Appl. Polym. Sci.31(7):2275-2302.nFrazier, C. E. 2003. Isocyanate wood binders. In Handbook of Adhesive Technology, 2nd ed., A. Pizzi and K.L. Mittal, eds., Marcel Decker, New York, NY.nFrazier, C. E., R. Schmidt, and J. Ni. 1996. Towards a molecular understanding of wood-isocyanate adhesive bondline. Pages 383-391 in Proc. 3rd Pacific Rim Bio-based Composite Symposium. Dec 2-5, Kyoto, Japan.nFrihart, C. R. 2004. Adhesive interaction with wood. Pages 29-53. In Fundamentals of Composite Processing. Proceedings of a workshop, Nov 5-6, 2003, Madison, WI. Gen. Tech. Rep. FPL-GTR-149. USDA, For. Serv., For. Prod. Lab.nFuruno, T., and H. Saiki. 1988. Comparative observation with fluorescence and scanning electron microscopy of cell walls adhering to the glue on fractured surfaces of wood-glue joints. Mokuzai Gakkaishi34(5):409-416.nFuruno, T., C-Y. Hse, and W. A. Côté. 1983a. Observation of microscopic factors affecting strength and dimensional properties of hardwood flakeboard. Pages 297-312. In Proc. 17th Int. Particleboard Symp., Washington State Univ., Pullman, WA.nFuruno, T., H. Saiki, T. Goto, and H. Harada. 1983b. Penetration of glue into the tracheid lumina of softwood and the morphology of fracture by tensile shear tests. Mokuzai Gakkaishi29(1):43-53.nFuruno, T., Y. Immamura, and H. Kajita. 2004. The modification of wood by treatment with low molecular weight phenol-formaldehyde resin: A properties enhancement with neutralized phenolic-resin and resin penetration into wood cell walls. Wood Sci. Technol.37:349-361.nGindl, W., and H. S. Gupta. 2002. Cell-wall hardness and Young's modulus of melamine-modified spruce wood by nano-indentation. Composites, Part A33:1141-1145.nGindl, W., E. Dessipri, and R. Wimmer. 2002. Using UV-microscopy to study diffusion of melamine-urea formal-dehyde resin in cell walls of spruce wood. Holzforschung56:103-107.nGindl, W., E. Dessipri, T. Schoberl, H. L. Lichtenegger, and P. Fratzl. 2004. Mechanical properties of spruce wood cell walls by nanoindentation. Appl. Phys. A: Mat. Sci. Proc.79(8):2069-2073.nGollob, L. 1989. The correlation between preparation and properties in phenolic resins. Pages 121-153. In A. Pizzi, ed., Wood Adhesives Chemistry and Structure, Marcel Dekker, New York, NY.nGollob, L., R. L. Krahmer, J.D. Wellons, and A. W. Christiansen. 1985. Relationship between chemical characteristics of phenol-formaldehyde resins and adhesive performance. Forest Prod. J.35(3):42-48.nHarada, H., G. W. Davies, and K. F. Plomley. 1968. Preliminary microscopic studies of wood structure and adhesion in plywood. Forest Prod. J.18(2):86-90.nHare, D. A., and N. P. Kutscha. 1974. Microscopy of eastern spruce plywood gluelines. Wood Sci.6(3):294-304.nHancock, W. V., and P. L. Northcott. 1961. Microscopic identification of undercured glue bonds in plywood. Forest Prod. J.11(7):316-319.nHse, C. H. 1968. Gluability of southern pine earlywood and latewood. For. Prod. J.18(12):32-36.nHse, C. H. 1971. Properties of phenolic adhesives as related to bond quality in southern pine plywood. Forest Prod. J.21(1): 44-52.nHse, C. H., and M. Kuo. 1988. Influence of extractives on wood gluing and finishing—a review. Forest Prod. J.38(1):52-56.nJohnson, S. E., and F. A. Kamke. 1992. Quantitative analysis of gross adhesive penetration in wood using fluorescence microscopy. J. Adhesion40:47-61.nJohnson, S. E., and F. A. Kamke. 1994. Characteristics of phenol-formaldehyde adhesive bonds in steam injection pressed flakeboard. Wood Fiber Sci.26(2):259-269.nKamke, F. A. 1995. Unpublished research. Virginia Polytechnic Institute and State University, Blacksburg, VA.nKamke, F. A. 2004. Adhesive penetration. In Wood Adhesion Problem Solving—The Isocyanate Dimension, WBC Center short course, Blacksburg, Virgina, November 16-17, 2004. Wood-Based Composites Center, Virginia Polytechnic Institute and State University, Blacksburg, VA. 21 pp.nKamke, F. A., D.T. Keane, J.R. Loferski, and C. D. Kamke. 2004. 3D visualization of an adhesive bondline. In Proc. Spring Meeting of Wood-Based Composites Center, April 20-21, 2004, St. Paul, Minnesota, Wood-Based Composites Center, Blacksburg, VA. 12 pp.nKoran, Z., and R. C. Vasishth. 1972. Scanning electron microscopy of plywood glue lines. Wood Fiber.34(2): 202-209.nKuo, M. 1998. Microscopic evaluation of glue bond performance. Pages 326-340. In C-Y Hse, S. J. Branham, and C. Chou, eds. Adhesive Technology and Tropical Wood Products, Taiwan Forestry Research Institute, Taipei, Taiwan.nKutscha, N. P., and R. W. Caster. 1987. Factors affecting the bond quality of hem-fir finger joints. Forest Prod. J.37(4):43-48.nLaborie, M-P. G. 2002. Investigation of the wood/phenol-formaldehyde adhesive interphase morphology. PhD dissertation, Virginia Polytechnic Institute and State University, Blacksburg, VA. 214 pp.nLehmann, W. F. 1968. Resin distribution in flakeboard shown by ultraviolet light photography. Forest Prod. J.18(10):32-34.nLevenspiel, O. 1984. Engineering flow and heat exchange. Plenum Press, New York, NY. 366 pp.nMarcinko, J. J., S. Devathala, P. L. Rinaldi, and S. Bao. 1998. Investigating the molecular and bulk dynamics of PMDI/wood and UF/wood composites, Forest Prod. J.48(6):81-84.nMarra, A. A. 1992. Technology of wood bonding: Principles in practice, 1 Ed., Van Nostrand Reinhold, New York. Pp. 76-80.nMiroy, F., P. Eymard, and A. Pizzi. 1995. Wood hardening by methyoxymethyl melamine. Holz Roh-Werkst.53:276.nNakata, K., H. Sugimoto, M. Inoue, and S. Kawai. 1997. Development of compressed wood fasteners for timber construction. 1. Mechanical properties of phenolic resin impregnated compressed laminated veneer lumber. Mokuzai Gakkaishi43(1):38-45.nNearn, W. T. 1974. Application of ultrastructure concept in industrial wood products research. Wood Sci.6(3):285-293.nPizzi, A. 1994. Advanced wood adhesives technology. Marcel Dekker, Inc. New York, NY. 289 pp.nRapp, A. O., H. Bestgen, W. Adam, and R. D. Peek. 1999. Electron loss spectroscopy (EELS) for quantification of cell-wall penetration of a melamine resin. Holzforschung53:111-117.nSaiki, H. 1984. The effect of the penetration of adhesives into cell walls on the failure of wood bonding. Mokuzai Gakkaishi30(1):88-92.nSernek, M. 2002. Comparative analysis of inactivated wood surfaces. PhD dissertation, Virginia Polytechnic Institute and State University, Blacksburg, VA. 179 pp.nSernek, M., J. Resnik, and F. A. Kamke. 1999. Penetration of liquid urea-formaldehyde adhesive into beech wood. Wood Fiber Sci.31(1):41-48.nSernek, M., F. A. Kamke, and W. G. Glasser. 2004. Comparative analysis of inactivated wood surfaces. Holzforschung58:22-31.nShaler, S. M., D. T. Keane, H. Wang, L. Mott, E. Landis, and L. Holtxman. 1998. Microtomography of cellulosic structures. Pages 89-96. In TAPPI Proc. Process and Product Quality Conference, Milwaukee, WI, October 1998.nShams, I., H. Yano, and K. Endou. 2004. Compressive deformation of wood impregnated with low molecular weight phenol formaldehyde (PF) resin I: Effects of pressing pressure and pressure holding. J. Wood Sci.50: 337-342.nShaw, D. J. 1991. Introduction to colloid and surface chemistry. Butterworth Heinemann Ltd, Oxford, UK. 306 pp.nSiau, J. F. 1995. WOOD: Influence of Moisture on Physical Properties. Virginia Tech, Blacksburg, VA, Pub. No. 7282 Forest Products Society, Madison, WI., 227 pp.nSmith, L. A. 1971. Resin penetration of wood cell walls—Implications for adhesion of polymers to wood. PhD Thesis. SUNY, Syracuse, NY. 175 pp.nStephen, R. S., and N. P. Kutscha. 1987. Effect of resin molecular weight on bonding flakeboard. Wood Fiber Sci.19(4):353-361.nTarkow, H., W. C. Feist, and C. F. Southerland. 1966. Penetration versus molecular size—interaction of wood with polymeric materials. Forest Prod. J.16(10):61-65.nWhite, M. S. 1977. Influence of resin penetration on the fracture toughness of wood adhesive bonds. Wood Sci.10(1):6-14.nWhite, M. S., G. Ifju, and J. A. Johnson. 1977. Method for measuring resin penetration into wood. Forest Prod. J.27(7): 52-54.nWilson, J. B., and R. L. Krahmer. 1978. The wetting and penetration of phenolic and lingo-sulfonate resins as possible indicators of bond strength for board. Pages 305-315. In Proc. 12th Int. Particleboard Symp., Washington State Univ., Pullman, WA.nZheng, J. 2002. Studies of PF resole/isocyanate hybrid adhesives. PhD dissertation. Virginia Polytechnic Institute and State University, Blacksburg, VA. 198 pp.n
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