Compressed and moulded wood from processing to products

Abstract This paper presents the state of the art of different wood densification processes as one emerging process technology. The main principles for the processes are discussed, such as bulk and surface densification, bending, moulding of shells and tubes, as well as methods for reducing the shape memory effect of densified wood. The main challenges are in the field of scaling up to industrial applications. To provide a better understanding with this regard, some relevant scientific results are presented. Furthermore, the discussion considers the contribution of thermo-hydro and thermo-hydro-mechanical processes to a sustainable and low-carbon economy.

[1]  Y. Chui,et al.  Effects of hot-pressing on properties of white spruce , 1997 .

[2]  Niels Morsing,et al.  Densification of Wood.: The influence of hygrothermal treatment on compression of beech perpendicular to gain , 1998 .

[3]  Dick Sandberg,et al.  The thermo-hydro-mechanical processing of wood. , 2012 .

[4]  H. Thoemen,et al.  Measuring and Simulating the Effects of the Pressing Schedule on the Density Profile Development in Wood-Based Composites , 2008 .

[5]  J. Wehsener,et al.  Festigkeitsuntersuchungen an Fichtenpressholz (FPH) , 2004, Holz als Roh- und Werkstoff.

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

[7]  Frank Werner,et al.  Wooden building products in comparative LCA: A literature review , 2007 .

[8]  P. Haller,et al.  Fiber-Reinforced Plastic-Confined Wood Profiles Under Axial Compression , 2010 .

[9]  M. Hughes,et al.  Surface modification of Scots pine: the effect of process parameters on the through thickness density profile , 2011 .

[10]  P. Haller,et al.  Formholzrohre – Stand der Forschung und Anwendungen , 2013 .

[11]  Petr Hajek,et al.  Structural, economic and environmental performance of fibre reinforced wood profiles vs. solutions made of steel and concrete , 2009 .

[12]  P. Kärenlampi,et al.  Effect of temperature and compression on the mechanical behavior of steam-treated wood , 2003, Journal of Wood Science.

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

[14]  Meng Gong,et al.  Fracture and fatigue in wood , 2003 .

[15]  F. Kamke,et al.  Microstructure of viscoelastic thermal compressed (VTC) wood using computed microtomography , 2012, Wood Science and Technology.

[16]  M. Wolcott,et al.  Fundamentals of flakeboard manufacture: viscoelastic behavior of the wood component. , 1990 .

[17]  M. Norimoto,et al.  Influence of Thermal Softening and Degradation on the Radial Compression Behavior of Wet Spruce , 1998 .

[18]  Y. Shinoda,et al.  Compressive-Molding of Wood by High-Pressure Steam-Treatment: Part 1. Development of Compressively Molded Squares from Thinnings , 1998 .

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

[20]  B. Persson,et al.  Plastic deformation in small clear pieces of Scots pine (Pinus sylvestris) during densification with the CaLignum process , 2004, Journal of Wood Science.

[21]  K. Ando,et al.  Mechanism for deformation of wood as a honeycomb structure I: Effect of anatomy on the initial deformation process during radial compression , 1999, Journal of Wood Science.

[22]  Parviz Navi,et al.  Combined Densification and Thermo-Hydro-Mechanical Processing of Wood , 2004 .

[23]  L. Salmén,et al.  Softening Temperature of Moist Wood Measured by Differential Scanning Calorimetry , 1990 .

[24]  R. Rowell,et al.  Fixation of compressive deformation in wood by pre-steaming , 2008 .

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

[26]  Bo Kasal,et al.  Shake table tests of small- and full-scale laminated timber frames with moment connections , 2009 .

[27]  Frederick A. Kamke,et al.  Fundamentals of flakeboard manufacture: internal-mat conditions. , 1988 .

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

[29]  M. Wolcott,et al.  Fundamental Aspects of Wood Deformation Pertaining To Manufacture of Wood-Based Composites , 1994 .

[30]  J. Y. Wang,et al.  Effect of grain orientation and surface wetting on vertical density profiles of thermally compressed fir and spruce , 2005, Holz als Roh- und Werkstoff.

[31]  F. Kamke,et al.  Investigations of Flakeboard Mat Consolidation. Part I. Characterizing The Cellular Structure , 2007 .

[32]  Compression of wood under saturated steam, superheated steam, and transient conditions at 150°C, 160°C, and 170°C , 2010, Wood Science and Technology.

[33]  C. Cherif,et al.  Textile reinforcement of multidimensional formable wood , 2014, European Journal of Wood and Wood Products.

[34]  M. Norimoto,et al.  Stress Relaxation of Sugi (Cryptomeria japonica D.Don) Wood in Radial Compression under High Temperature Steam , 1999 .

[35]  C. R. Welzbacher,et al.  Thermo-mechanical densification combined with thermal modification of Norway spruce (Picea abies Karst) in industrial scale – Dimensional stability and durability aspects , 2008, Holz als Roh- und Werkstoff.

[36]  K. Laine.  Improving the properties of wood by surface densification , 2014 .

[37]  F. Kamke,et al.  The influence of viscoelastic thermal compression on the chemistry and surface energetics of wood , 2008 .

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

[39]  F. Kamke,et al.  MODE II FRACTURE BEHAVIOR OF BONDED VISCOELASTIC THERMAL COMPRESSED WOOD , 2008 .

[40]  A. Stamm,et al.  Staybwood—Heat-Stabilized Wood , 1946 .

[41]  J. Winandy,et al.  THERMAL DEGRADATION OF WOOD FIBERS DURING HOT-PRESSING OF MDF COMPOSITES: PART I. RELATIVE EFFECTS AND BENEFITS OF THERMAL EXPOSURE , 2007 .

[42]  Timothy G. Rials,et al.  Relaxation behaviour of the amorphous components of wood , 1987 .

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

[44]  F. Kamke,et al.  The mechanical properties of densified VTC wood relevant for structural composites , 2008, Holz als Roh- und Werkstoff.

[45]  Peer Haller,et al.  Analytical assessment of the load-carrying capacity of axially loaded wooden reinforced tubes , 2010 .

[46]  Frederick A. Kamke,et al.  Density profile relation to hardness of viscoelastic thermal compressed (VTC) wood composite , 2011, Wood Science and Technology.

[47]  H. Pereira,et al.  Influence of steam heating on the properties of pine (Pinus pinaster) and eucalypt (Eucalyptus globulus) wood , 2007, Wood Science and Technology.

[48]  A. Stamm,et al.  Wood based materials , 1975 .

[49]  P. Haller,et al.  Concepts for textile reinforcements for timber structures , 2007 .

[50]  T. Sadoh.  Viscoelastic properties of wood in swelling systems , 1981, Wood Science and Technology.

[51]  Jiabin Cai,et al.  Optimization of the Combined Modification Process of Thermo-Mechanical Densification and Heat Treatment on Chinese Fir Wood , 2013 .

[52]  D. Sandberg,et al.  Shape stability of modified engineering wood product subjected to moisture variation , 2011 .

[53]  F. Kollmann,et al.  Technologie des Holzes , 1936 .

[54]  M. Gong,et al.  Interactive effect of surface densification and post-heat-treatment on aspen wood , 2010 .

[55]  Yujie Meng,et al.  Evaluation of the effects of compression combined with heat treatment by nanoindentation (NI) of poplar cell walls , 2014 .

[56]  A. Wagenführ,et al.  Testing of set recovery of unmodified and furfurylated densified wood by means of water storage and alternating climate tests , 2013 .

[57]  D. Sandberg,et al.  A New method for bending solid wood – high frequency heating of beech , 2005 .

[58]  Y. Chui,et al.  Stress-Strain Response of Wood Under Radial Compression. Part I. Test Method and Influences of Cellular Properties , 2000 .

[59]  Ahmed Koubaa,et al.  Densification of wood veneers by compression combined with heat and steam , 2011, European Journal of Wood and Wood Products.

[60]  F. Kamke,et al.  Density profile and morphology of viscoelastic thermal compressed wood , 2009, Wood Science and Technology.

[61]  Lauri Rautkari,et al.  Properties and set-recovery of surface densified Norway spruce and European beech , 2010, Wood Science and Technology.

[62]  Helena Pereira,et al.  Wood modification by heat treatment: a review. , 2009 .

[63]  C. Popescu,et al.  Evaluation of the thermal stability and set recovery of thermo-hydro-mechanically treated lime (Tilia cordata) wood , 2013, Wood Science and Technology.

[64]  J. Nairn.  Numerical Simulations of Transverse Compression and Densification in Wood , 2006 .

[65]  M. Hughes,et al.  Reducing the set-recovery of surface densified solid Scots pine wood by hydrothermal post-treatment , 2012, European Journal of Wood and Wood Products.