Koto (wood)
Koto is the name of a type of wood from trees of some species of the genus Pterygota , for example Pterygota macrocarpa , from the family of the Malvaceae (Mallow family) and the subfamily of the Sterkulia family . These trees are generally found in tropical regions and their wood is particularly used for decorative veneers .
description
Koto trees are naturally found in tropical regions such as West Africa , South and Central America , South and Southeast Asia , and Madagascar . They are traded as important imported timbers, most of them from West Africa and Southeast Asia. Trees of the genus Pterygota are deciduous trees and reach a height of up to 50 m with a diameter of up to 120 cm.
Wood
Color and structure
The color, structure and properties of the woods, depending on their origin and type, differ only marginally, so that they can be described for the entire genus. The heartwood is pale yellow when it is fresh and is difficult to distinguish from the sapwood, which only darkens slightly over time. In the cross-section, the white to light yellowish parenchyma bands and the scattered pores are macroscopically recognizable. Fine lines can be seen on the tangential surfaces, which are caused by the wood rays.
Machinability
| Technical wood data | |
|---|---|
| Bulk density | 0.56 g / cm³ |
| modulus of elasticity | 9000 N / mm² |
| Compressive strength | 49 N / mm² |
| tensile strenght | 95 N / mm² |
| Flexural strength | 86 N / mm² |
Koto is a moderately heavy wood and is easy to machine. Only mineral deposits can quickly dull the tools. It can be glued, nailed and screwed on and easily stained in different tones thanks to the naturally light base color.
Drying
The drying should take place relatively slowly, this counteracts the risk of deformation or cracking, which is relatively low with Koto. If the drying time is too fast, however, quality losses could occur more frequently.
Natural durability
The wood is not very durable as it is susceptible to fungus and insects in fresh or damp locations. Discoloration is also possible (bruises). However, applying wood preservatives is straightforward. In general, the wood should therefore only be used indoors.
use
Use indoors in dry locations for non-load-bearing purposes. Mainly as solid wood for furniture and interior design, profiled wood for ceiling and wall cladding, strips for picture frames. As a sliced veneer, the wood is used as a flat element for walls, ceilings and doors; Rotary veneers are processed into decorative and industrial plywood in the countries of origin.
exchange
Other light-colored woods are used as replacement woods. Examples of this are ramin , limba or, if subdued (leads to an oak-like color), oak in the furniture or paneling area.
annotation
By dampening the wood, Koto is given an oak-like, yellowish-brown tint. The wood produced in this way is marketed under the names "Anatolia" or "Antolia".
Inhaling the wood dust can cause digestive problems in a few people.
literature
- RH Farmer: Handbook of Hardwoods. 2nd Edition, BRE, Princess Risborough Laboratory, 1972.
- J. Sell: Properties and parameters of types of wood. Lignum, Baufachverlag AG Zurich, 1989, ISBN 3-87181-509-8 .
- Anonymous: Atlas of tropical woods. 1: Africa , ATIBT, Nogent-sur-Marne F 1986.
- K.-G. Dahms: African export timbers. DRW-Verlag, Stuttgart 1978.
- FPRL Princes Risborough / GB 1972. H. Gottwald: Handelshölzer. Ferdinand Holzmann-Verlag, Hamburg 1958. H. Gottwald and HG Richter: Koto / Pterygota - woods of three continents. Holzzentralblatt 110 (151), Stuttgart 1984.
- A. Walker: Atlas of the species of wood. Stuttgart, Germany: Eugen Ulmer KG, 2007, ISBN 978-3-8001-5441-8 .
- R. Wagenführ: wooden atlas. 6th edition, Carl Hanser Verlag Munich, 2007, ISBN 978-3-446-40649-0 .
- D. Louppe, AA Oteng-Amoako & M. Brink: Plant resources of tropical Africa. 7 (1): Timbers 1, PROTA Foundation, Backhuys Publishers, CTA Wageningen, 2008, ISBN 978-90-5782-209-4 .
- I. Soerianegara & RHMJ Lemmens: Plant resources of South-East Asia. 5 (1) Timber trees: Major commercial timbers, Pudoc Scientific Publishers, Wageningen, 1993, ISBN 90-220-1033-3 , p. 384 ff.