Afzelia

Origin	mainly Central Africa, partly Asia
Raw density	0.75 g/cm³
Durability class	1
Radial shrinkage	3,1 – 4 %
Tangential shrinkage	3,6 – 5 %
Wood color	Light brown to reddish
Wood structure	Coarse-pored
Use	e.g. profiled wood, sliced veneer, parquet

Afzelia is found in the tropical regions of Africa and Asia. There are fourteen known species. The economically most important Afzelia woods come from Africa. The Asian species play only a minor role in timber production. This article therefore focuses on the African woods with the trade name Afzelie or Doussié.

Classification by type and origin

Depending on its origin, the wood of the genus Afzelia can have different characteristics.

• Afzelia bipidensis Harms: Angola, Cameroon, Gabon, Congo, Nigeria
• Afzelia pachyloba Harms: Cameroon, Gabon, Congo, Nigeria
• Afzelia africana Sm.:Nigeria
• Afzelia quanzensis Welw.:Congo, Mozambique, Tanzania

The well-known Asian species of Afzelia are similar to Merbau. Afzelias  Substitutes are walnut and other dark-toned tree species of the so-called mahogany species.

With an average density of 820 kg/m³, its hardness of 8200 N is significantly higher than teak (4450 N) and oak (4200 – 6300 N). Due to this hardness property of afzelia, great care must be taken during the drying process to ensure that the drying process is carried out slowly, as  Afzelia wood warps if the technical drying process is too fast.

Doussié the best of Afzelia

The so-called Doussié, also known in German as Edelkirsche or Brillantkirsche, in which only the species Afzelia bipidensis and Afzelia pachyloba are united – also as  Afzelia spp. (Afzelia, doussié)  is considered to be the best quality Afzelia wood on the market. Because Afzelia, Doussié has a very strong resistance to fungal attack.

Due to the high bulk density of 820 kg/m³, Afzelia has a very high thermal conductivity. This property is used for heated parquet floors where Afzelia is very often used. Afzelia is used in door and window construction (frames), in boat building, for stairs, tables and garden furniture.

In the Netherlands Afzelia    was also used for water dams(today increasingly azobé), but Afzelia can also be used for constructions with high tensile forces, such as in bridge construction.

Due to its wood-chemical properties, Afzelia can even be used for barrels with chemical contents. Afzelia can also be found in art, as it is well suited to the production of wood carvings and turned forms such as jugs.

Technical properties of Afzelia

The wood-physical and wood-mechanical properties of Afzelia are reflected in its high dimensional stability. The shrinkage or swelling is 1.0 % radially atand 1.4 % tangentially. All these figures are based on a moisture content of 12%.

The ratio between stress and strain caused by the application of force on the elasticity of the wood is specified for Afzelia with an MOE of 15,200 N /mm2 and the bending and compressive strength up to fracture, the MOR, is specified as 125 N/mm2.

All these positive properties of Afzelia wood lead to the question of the durability of the wood. As already described in the possible uses that Afzelia offers people.

We have found that Afzelia is used very successfully outdoors. So if Afzelia is suitable for use in water, it must have a shelf life of 1, as infestation by water borers and putrefactive fungi is very high in this environment. But Afzelia is also characterized by its special resistance to fungal and insect infestation outside the water, with Doussier from West Africa being particularly noteworthy.

Sources:

1. Afzelia spp. (Afzelia, doussié)‘Richter, H.G., and Dallwitz, M.J. 2000 onwards. Commercial timbers: descriptions, illustrations, identification, and information retrieval. In English, French, German, Portuguese, and Spanish. Version: June 25th, 2009.
2. Wikipedia Afzelia
3. Koninklijke Houthandel G. Wijma & Zonen B.V.
4. Timber species from the tropical regions (Vos, Valentijn de; 2011); van Hall Larenstein University of Applied Sciences.