Wood Production, Wood Technology, and Biotechnological ... - GWDG

Panel Boards
Plywood OSB Other
21%
7%
6% 4%
MDF
62%
Particle board
Fig. 2 Panel board production in Europe in the year 2005 (according to EPF 2006 and
Marutzky 2006; see also VHI 2007a)
During the transformation into plane panel boards, the major problems of
solid wood become ineffective. Due to the gluing of wooden material in different
fibre directions, the dimensional stability in panel boards defeats that of compact
wood in strength and by a better balance. In addition, panel boards are characterised
by partly better static properties and reduced swelling-shrinking anisotropies
(see for example Niemz & Poblete 1996, Wu 1999, Thomas 2001, Lee & Wu
2002, Miyamoto et al. 2002, Sonderegger & Niemz 2006).
The availability of high quality sawnwood is generally limited. Depletion of
forests, particularly also the tropical forests, to meet the demand for high-quality
construction material has devastating ecological consequences (see Chapters 2 to 5
in this book). Another very important reason for the production of wood
composites is therefore to save natural resources for sustainability. By panel board
production, wood types with properties less favourable for application in compact
form, low grade wood material from forests (e.g. from thinning in young forests,
wastes from felling), left over parts from the timber industry and used wood
products discarded for recycling can be made use of in order to convert these into
a highly valuable product with excellent properties (for details on recycling see
Chapter 20 of this book).
The most important panel boards are particle boards, medium-density
fibreboards (MDF), oriented strand boards (OSB) and plywood (Youngquist
et al. 1997, Kharazipour 2004; Fig. 1 and 2). A particle board is defined as a woodbased
panel manufactured under pressure and heat from particles of wood (wood
chips) usually under the addition of an adhesive (EPF 2005). MDF is made from
lignocellulosic fibres combined with a synthetic resin in a dry process by hot-pressing
(Bolton & Humphrey 1988, Thoemen & Humphrey 2003). OSB is produced
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