Batai


INTRODUCTION

The Standard Malaysian Name for the timber of Albizia spp. (excluding A. splendens) and Paraserianthes falcataria (Leguminosae). Vernacular names applied appear to be very uniform in that only batai with various epithets is used throughout the country. Major species include Albizia chinensis, A. dolichandena, A. lebbeck, A. pedicellata; and Paraserianthes falcataria. The sapwood is not always defined from the heartwood, which is white to light brown with a pink tinge.

Also known as Siris (India); Jeungjing, Sengon, Sengon laut and Sika (Indonesia); White albizia (Papua New Guinea); and Moluccan sau (Philippines).


DENSITY

The timber is soft to hard and light to very heavy with a density of 270-880 kg/m3 air dry.


NATURAL DURABILITY

The timber is non-durable.


PRESERVATIVE TREATMENT

It is not easily treated, especially the heartwood.


TEXTURE

Texture is coarse and even with deeply interlocked and spiral grain.


STRENGTH PROPERTIES

Only P. falcataria, representing the lighter species has been tested at the Forest Research Institute Malaysia (FRIM). The timber falls into Strength Group D (Burgess, 1958) or SG7 (MS 544:Part 2:2001)


MACHINING PROPERTIES

It is easy to resaw and cross-cut. Planing is easy and the surface produced is smooth.

  
NAILING PROPERTY

Nailing property is rated as good, although it has been reported that this timber does not hold nails satisfactorily.


AIR DRYING

The timber seasons fairly rapidly with slight end-checking, splitting and insect attack as the main sources of degrade. The timber is also very prone to sapstain fungal attack. 13 mm thick boards take approximately 1.5 months to air dry, while 38 mm thick boards take 3 months.


SHRINKAGE

Shrinkage is high. Radial shrinkage averages 2%, while tangential shrinkage averages 3.7%.


MOVEMENT IN SERVICE

The movement of seasoned timber is classified under Type II.


USES

The timber is suitable for general utility purposes, picture frames, artificial limbs and plywood. Paraserianthes falcataria is widely planted as a source of fast growing industrial timber.


REFERENCES

  1. Burgess, H. J. 1958. Strength Grouping of Malaysian Timbers. Malayan Forest Service Trade Leaflet No.25. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 15 pp.
  2. MS 544: Part 2: 2001: Code Of Practice For Structural Use Of Timber. PermissibleStress Design of Solid Timber.
  3. Wong, T. M. 1982. A Dictionary of Malaysian Timbers. Revised by Lim, S. C. & Chung, R. C. K. Malayan Forest Record No. 30. Forest Research Institute Malaysia, Kuala Lumpur. 201 pp.