Tropical wood’s position in key sectors of the European
market has long been based on its natural qualities of
durability, toughness and resilience to wear. In the past,
softwoods, temperate hardwoods and composite panels
have generally been unable to match these qualities of
tropical hardwoods. Preservative treatments have offered
only a partial solution, being an emotive environmental
subject because the best treatments, such as creosote and
Copper Chromium Arsenic, are also toxic to humans.
Creosote and CCA have been heavily legislated against in
Europe limiting their use to specialist applications such as
sleepers and bridge decks. In practice, low levels of
demand have meant that these traditional forms of
treatment are no longer financially viable in many
countries. Some progress has been made with modern
pressure/vacuum treatment processes, but even with these
the chemical often only penetrates a few millimeters so all
cuts and holes have to be made good before treatment.
The problems associated with traditional forms of
preservation have stimulated a search for alternative
treatments. Two processes have been identified by the
softwood industry as having particular potential, namely
heat treatment and acetylation. Both these have now
developed to such an extent that they are beginning to
offer a significant competitive challenge to tropical
hardwoods.
The Scandinavian companies Finnforest and Stora Enso
are now producing Thermowood, a heat treated product
made by steam heating softwood to temperatures over
200C, driving out moisture and resin to enhance durability
and stability. The modified product is being marketed for
decking, garden furniture and external cladding. Kebony, a
product from Norway is produced by a similar process
except that ‘tropical-wood-colour’ is added to the
candidate softwood by impregnating furfuryl (a byproduct
from sugar making) before being subjected to
intense heating. Other heat treated brands include Plato
Wood and Lignia.
Acetylation, involves the use of naturally occurring acetic
acid to alter the molecular structure of wood. The treated
timber is more durable and stable without any marked
effect on visual appearance. Titan Wood’s Accoya is
probably the most well known brand of this material and is
being marketed for exterior joinery applications,
particularly windows, doors, conservatories and cladding.
Accoya claims a service life of 50 years and a first
maintenance (of paints and coatings) period of 12 years.
At present, the ability of these products to compete with
tropical hardwoods is constrained by price. For example
Kebony is currently priced at between USD4,000 and
USD14,000 per m³ depending on quality, and is therefore
targeted specifically at the high end teak market. However
price levels are expected to come down as capacity
increases. In June 2009, the German trade journal EUWID
reported that European production capacity of thermally
treated wood is now around 160,000 m³, with known
capacity of 80,000 m³ in Scandinavia, 40,000 m³ in
German-speaking countries of central Europe, 30,000 m³
in the Netherlands, and 8,000 m³ in the Baltics. In 2009,
reported projects in Germany and Finland will extend
production by a further 20,000 m³. These figures may not
seem high, but are significant when set against the 600,000
m³ combined annual EU import volume of meranti and
sapele, the EU’s two leading tropical joinery species.
In August, the UK trade journal TTJ reported claims by
Titan Wood that its two largest UK distributors had shown
sales increases of more than 200% in the May to July 2009
period compared with the same period in 2008 –
remarkable growth during a period of generally sluggish
demand. TTJ notes that one of these distributors,
International Timber, puts the growth down to durability
and aesthetic reasons, plus people looking for a sustainable
alternative to tropical hardwood. Titan Wood also reckons
that Accoya has potential to take market share from steel,
PVCu, aluminium and concrete.
In a notable development from the perspective of tropical
hardwood plywood, in June 2009 Titan Wood and Medite
Europe Limited signed a joint development agreement to
commercialise new MDF and OSB panels made from
acetylized ‘Tricoya’ wood elements. By protecting the
OSB from wood rot and significantly improving durability
and dimensional stability, the market development strategy
for acetylized OSB targets external applications currently
occupied by tropical hardwood plywood in Europe.
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