A two-stage thermal modification of wood

Thermal modification or heat treatment is an effective method to improve the dimensional stability and biological durability of wood. An undesired side effect is the reduction of mechanical properties of wood, mainly due to the high temperatures involved (150-280°C). In this thesis the effects of heat treatment on wood properties are discussed in relation to anatomical and molecular changes found in wood after heat treatment. The results are based on investigations of a full-scale industrial heat treatment method under relative mild conditions (< 200°C) including a moist and dry treatment stage. Several changes and/or modifications of the main components of wood (cellulose, hemicelluloses and lignin) appear to be involved in the effects of heat treatment on important wood properties like dimensional stability, strength/stiffness and biological durability. Although the effect of heat treatment on the anatomical structure of wood is limited, changes have been found affecting the properties of wood. This thesis provides a better understanding of thermal modification, which probably contributes to a more controlled use of heat-treated wood in service conditions.

[1]  J. Winandy.  EFFECTS OF TREATMENT, INCISING, AND DRYING ON MECHANICAL PROPERTIES OF TIMBER , 1996 .

[2]  P. Wood,et al.  A Mechanism for Production of Hydroxyl Radicals by the Brown-Rot Fungus Coniophora Puteana: Fe(III) Reduction by Cellobiose Dehydrogenase and Fe(II) Oxidation at a Distance from the Hyphae. , 1997, Microbiology.

[3]  P. Perré,et al.  Choix d'un modèle de pyrolyse ménagée du bois à l'échelle de la microparticule en vue de la modélisation macroscopique , 2006 .

[4]  B. Goodell,et al.  Non-enzymatic iron, manganese, and copper chemistry of potential importance in wood decay. , 2003 .

[5]  J. W. Koenigs.  Hydrogen Peroxide and Iron: A Proposed System for Decomposition of Wood by Brown-rot Basidiomycetes , 1974 .

[6]  H. Militz,et al.  Characterisation of thermally modified wood: molecular reasons for wood performance improvement , 1998, Holz als Roh- und Werkstoff.

[7]  R. Young.  The chemistry of solid wood , 1985, Wood Science and Technology.

[8]  G. T. Pott.  Natural Fibers with Low Moisture Sensitivity , 2004 .

[9]  Alfred J. Stamm,et al.  Wood and Cellulose Science , 1964 .

[10]  Antonio Pizzi,et al.  Vibration welding of heat-treated wood , 2006 .

[11]  M. Boonstra,et al.  Semi-isostatic densification of heat-treated radiata pine , 2007, Wood Science and Technology.

[12]  T. Kirk,et al.  Wood Decay by Brown-Rot Fungi: Changes in Pore Structure and Cell Wall Volume , 1991 .

[13]  S. Ellis,et al.  Activated Self-Bonding of Wood and Agricultural Residues , 1994 .

[14]  T. Okano,et al.  Bending strength and toughness of heat-treated wood , 2000, Journal of Wood Science.

[15]  S. Takao,et al.  Organic Acid Production by Basidiomycetes , 1965 .

[16]  P. Navi,et al.  Effects of Thermo-Hydro-Mechanical Treatment on the Structure and Properties of Wood , 2000 .

[17]  J. A. Meyer.  Wood―polymer materials , 1981 .

[18]  Barry Goodell,et al.  Brown-rot fungal degradation of wood: our evolving view. , 2003 .

[19]  G. Goroyias,et al.  Heat treatment of wood strands for OSB production: effect on the mechanical properties, water absorption and dimensional stability , 2002 .

[20]  T. Highley,et al.  Manganese as a Probe of Fungal Degradation of Wood , 1989 .

[21]  A. Burmester.  Zur Dimensionsstabilisierung von Holz , 1975, Holz als Roh- und Werkstoff.

[22]  Otto Graf.  Prüfung von Holz , 1935 .

[23]  F. Schweingruber.  Anatomy of European woods. , 1990 .

[24]  M. Inoue,et al.  Crystallinity Changes of Wood by Heat or Steam Treatment , 1996 .

[25]  B. Kos̆iková,et al.  Interaction of lignin and polysaccharides in beech wood (Fagus sylvatica) during drying processes , 1999, Wood Science and Technology.

[26]  R. W. Kennedy.  Wood in transverse compression , 1968 .

[27]  G. Daniel,et al.  Low molecular weight chelators and phenolic compounds isolated from wood decay fungi and their role in the fungal biodegradation of wood , 1997 .

[28]  A. Pizzi,et al.  Optimising the properties of OSB by a one-step heat pre-treatment process , 2006, Holz als Roh- und Werkstoff.

[29]  T. Highley,et al.  Biotechnology in the study of brown- and white-rot decay. , 1998 .

[30]  F. Kollmann,et al.  Über das Sorptionsverhalten wärmebehandelter Hölzer , 1963, Holz als Roh- und Werkstoff.

[31]  Masafumi Inoue,et al.  Steam or Heat Fixation of Compressed Wood , 2007 .

[32]  W. Hillis,et al.  The Softening Temperatures of Wood , 1978 .

[33]  D. Fengel,et al.  Wood: Chemistry, Ultrastructure, Reactions , 1983 .

[34]  A. Pizzi,et al.  Correlation of 13C-NMR analysis with fungal decay tests of polymeric structural wood constituents. I. Basidiomycetes , 2006 .

[35]  H. Militz,et al.  Chemical changes in hydrothermal treated wood: FTIR analysis of combined hydrothermal and dry heat-treated wood , 2005, Holz als Roh- und Werkstoff.

[36]  Alfred J. Stamm,et al.  Principles of Wood Science and Technology , 2013, Springer Berlin Heidelberg.

[37]  M. Boonstra,et al.  Chemical analysis of heat treated softwoods , 2006, Holz als Roh- und Werkstoff.

[38]  W. Kaar,et al.  The complete analysis of wood polysaccharides using HPLC , 1991 .

[39]  J. A. Micales,et al.  Effect of aromatic monomers on production of carbohydrate-degrading enzymes by white-rot and brown-rot fungi , 1990 .

[40]  Alfred J. Stamm,et al.  Thermal Degradation of Wood and Cellulose , 1956 .

[41]  W. Astbury,et al.  Structure of Cellulose , 1944, Nature.

[42]  H. Binder,et al.  Dynamischer hydrothermaler Abbau von Holz , 1980 .

[43]  H. A. Schroeder,et al.  Chemical degradation of wood: the relationship between strength retention and pentosan content. , 2007 .

[44]  E. Cowling.  Comparative Biochemistry of the Decay of Sweetgum Sapwood by White-Rot and Brown-Rot Fungi , 1961 .

[45]  L. E. Wise,et al.  A CHLORITE HOLOCELLULOSE, ITS FRACTIONATION AND BEARING ON SUMMATIVE WOOD ANALYSIS AND STUDIES ON THE HEMICELLULOSES , 1946 .

[46]  W. M. C. McKenzie.  Design of Structural Timber , 2000 .

[47]  E. Sjöström,et al.  Wood Chemistry: Fundamentals and Applications , 1981 .

[48]  H. Militz,et al.  Effect of process conditions on moisture content and decay resistance of hydro-thermally treated wood. , 1971 .

[49]  W. E. Hillis,et al.  High temperature and chemical effects on wood stability , 2004, Wood Science and Technology.

[50]  A. Pizzi,et al.  Heat-treated timber: potentially toxic byproducts presence and extent of wood cell wall degradation , 2000, Holz als Roh- und Werkstoff.

[51]  W. Klauditz,et al.  Beiträge zur Kenntnis des Ablaufes, und der Wirkung thermischer Reaktionen bei der Bildung von Holzwerkstoffen , 1955, Holz als Roh- und Werkstoff.

[52]  P. Bekhta,et al.  Effect of High Temperature on the Change in Color, Dimensional Stability and Mechanical Properties of Spruce Wood , 2003 .

[53]  G. Daniel,et al.  Microview of wood under degradation by bacteria and fungi. , 2003 .

[54]  D. Goring,et al.  Thermal softening of lignin, hemicellulose and cellulose , 1963 .

[55]  A. Burmester.  Einfluß einer Wärme-Druck-Behandlung halbtrockenen Holzes auf seine Formbeständigkeit , 1973, Holz als Roh- und Werkstoff.

[56]  M. Boonstra,et al.  Optimisation of a two-stage heat treatment process: durability aspects , 2006, Wood Science and Technology.

[57]  R. Rowell.  Penetration and reactivity of cell wall components , 1984 .

[58]  Jerrold E. Winandy,et al.  The chemistry of wood strength , 2012 .

[59]  Antonio Pizzi,et al.  Bonding performance of heat treated wood with structural adhesives , 2008, Holz als Roh- und Werkstoff.

[60]  Antonio Pizzi,et al.  Wood bonding by vibrational welding , 2003 .

[61]  M. Wolcott,et al.  TEMPERATURE AND MOISTURE INFLUENCE ON COMPRESSION- RECOVERY BEHAVIOR OF WOOD , 2007 .

[62]  J. G. Palmer,et al.  Electron Microscopy of Cellulose Decomposition by Brown-Rot Fungi , 1983 .

[63]  J. Puls,et al.  Potential of Steaming Hardwoods and Straw for Feed and Food Production , 1978 .

[64]  L. Viikari,et al.  Investigations of Fresh and Biologically Decayed Birch , 1992 .

[65]  F. Kamke.  DENSIFIED RADIATA PINE FOR STRUCTURAL COMPOSITES , 2006 .

[66]  W. Schwald,et al.  Chromatographic analysis of biomass reaction products produced by hydrothermolysis of poplar wood , 1987 .

[67]  U. Bexell,et al.  Effects of semi-isostatic densification on anatomy and cell-shape recovery on soaking , 2006 .

[68]  A. Pizzi,et al.  A New Concept on the Chemical Modification of Wood by Organic Anhydrides , 1994 .

[69]  M. Sain,et al.  Wood-polymer composites , 2008 .

[70]  F. Kollmann,et al.  Änderungen der chemischen Zusammensetzung von Holz durch thermische Behandlung , 1965, Holz als Roh- und Werkstoff.

[71]  M. Boonstra,et al.  Effect of a two-stage heat treatment process on the mechanical properties of full construction timber , 2007 .

[72]  R. E. Mark.  Cell Wall Mechanics of Tracheids , 1967 .

[73]  R. Overend,et al.  Conversion and solubilization profiles of a prototype hardwood (Populus tremuloides) following aqueous thermomechanical pre-treatment , 1986 .

[74]  E. Giebeler.  Dimensionsstabilisierung von Holz durch eine Feuchte/Wärme/Druck-Behandlung , 1983, Holz als Roh- und Werkstoff.

[75]  Theodore C. Scheffer,et al.  O2 requirements for growth and survival of wood-decaying and sapwood-staining fungi , 1986 .

[76]  O. Faix,et al.  The influence of particle size and concentration in transmission and diffuse reflectance spectroscopy of wood , 1992, Holz als Roh- und Werkstoff.

[77]  J. A. Shields,et al.  Chemical and physical changes required for producing dimensionally stable wood-based composites , 1988, Wood Science and Technology.

[78]  H. Militz,et al.  Modification of solid wood: research and practical potential , 1997 .

[79]  S. Maunu,et al.  Magnetic Resonance Studies of Thermally Modified Wood , 2002 .

[80]  F. E. Bbauns.  Chemistry of lignin. , 1952 .

[81]  A. Pizzi,et al.  A study of the influence of solvents on the modification of wood with organic anhydrides , 1997 .

[82]  K. Jensen,et al.  Pathways for Extracellular Fenton Chemistry in the Brown Rot Basidiomycete Gloeophyllum trabeum , 2001, Applied and Environmental Microbiology.

[83]  G. O. Aspinall.  Chemistry of Cell Wall Polysaccharides , 1980 .

[84]  Stephen Y. Lin,et al.  Methods in Lignin Chemistry , 1992, Springer Series in Wood Science.

[85]  J. Parajó,et al.  Hydrothermal processing of lignocellulosic materials , 1999, Holz als Roh- und Werkstoff.

[86]  A. Enoki,et al.  Extracellular substance from the brown-rot basidiomycete Gloeophyllum trabeum that produces and reduces hydrogen peroxide , 1993 .

[87]  G. Halliwell.  CATALYTIC DECOMPOSITION OF CELLULOSE UNDER BIOLOGICAL CONDITIONS. , 1965, The Biochemical journal.

[88]  Nicolas Abatzoglou,et al.  Phenomenological kinetics of complex systems: mechanistic considerations in the solubilization of hemicelluloses following aqueous/steam treatments , 1991 .

[89]  A. Pizzi,et al.  Chemical Modification of Norway Spruce and Scots Pine. A 13 C NMR CP-MAS Study of the Reactivity and Reactions of Polymeric Wood Components with Acetic Anhydride , 1996 .

[90]  A. Pizzi,et al.  The effects of a two stage heat treatment process on the properties of particleboard , 2006, Holz als Roh- und Werkstoff.

[91]  Hiromi Tanaka,et al.  Degradation of Lignin-Related Compounds, Pure Cellulose, and Wood Components by White-Rot and Brown-Rot Fungi , 1988 .

[92]  T. Kirk,et al.  Mineralization of the methoxyl carbon of isolated lignin by brown-rot fungi under solid substrate conditions , 1990, Wood Science and Technology.

[93]  W. Brown,et al.  Structural features of cellulosic materials in relation to enzymic hydrolysis , 1969 .

[94]  H. Militz.  Heat Treatment Technologies in Europe : Scientific Background and Technological State-of-Art , 2004 .

[95]  A. Tillman,et al.  A Simplified Procedure for the Acetylation of Hardwood and Softwood Flakes for Flakeboard Production , 1986 .

[96]  O. Faix.  Practical uses of FTIR spectroscopy in wood science and technology , 1988 .

[97]  D. Hon,et al.  Wood and Cellulosic Chemistry , 1990 .

[98]  A. Pizzi,et al.  Durability of heat-treated wood , 2002, Holz als Roh- und Werkstoff.

[99]  J. Bourgois,et al.  Characterization and analysis of torrefied wood , 1988, Wood Science and Technology.

[100]  Harold Tarkow,et al.  Effect of Heat Upon the Dimensional Stabilization of Wood , 1953 .

[101]  R. Runkel,et al.  Zur Kenntnis des thermoplastischen Verhaltens von Holz , 1953, Holz als Roh- und Werkstoff.

[102]  B. L. Browning,et al.  Methods of wood chemistry , 1967 .

[103]  R. D. Peek,et al.  Upgrading of wood by application of an oil-heat treatment , 2000 .

[104]  J. W. Koenigs.  Production of Extracellular Hydrogen Peroxide and Peroxidase by Wood-Rotting Fungi , 1972 .

[105]  M. Petrič,et al.  Evolution of wood surface free energy after heat treatment , 2007 .

[106]  G. Keilich,et al.  Enzymatic degradation of cellulose, cellulose derivatives and hemicelluloses in relation to the fungal decay of wood , 1970, Wood Science and Technology.

[107]  S. Itakura,et al.  Hydroxyl radical generation and phenol oxidase activity in wood degradation by the white-rot basidiomycete Irpex lacteus , 2000 .

[108]  R. Guyonnet,et al.  Evaluation of heat-treated wood swelling by differential scanning calorimetry in relation to chemical composition , 2005 .

[109]  I. Sachs,et al.  The effects of elevated temperature on certain wood cells , 1967, Wood Science and Technology.

[110]  J. Weiland,et al.  Study of chemical modifications and fungi degradation of thermally modified wood using DRIFT spectroscopy , 2003, Holz als Roh- und Werkstoff.

[111]  A. Spurr.  A low-viscosity epoxy resin embedding medium for electron microscopy. , 1969, Journal of ultrastructure research.

[112]  A. Burmester,et al.  Quellungsverminderung von Holz in Teilbereichen der relativen Luftfeuchtigkeit , 1976, Holz als Roh- und Werkstoff.

[113]  T. Vuorinen,et al.  Heat‐treated softwood exposed to weathering , 2004 .

[114]  P. Steiner,et al.  THE BEHAVIOUR OF FIVE WOOD SPECIES IN COMPRESSION , 2002 .

[115]  C. Roy,et al.  Kinetic study of dilute-acid prehydrolysis of xylan-containing biomass , 1992, Wood Science and Technology.