White Seraya

INTRODUCTION

The Standard Malaysian Name for the timber of the lighter species of Parashorea (Dipterocarpaceae). This timber is confined to the states of Sabah and Sarawak. Vernacular names applied include urat mata (Sabah and Sarawak) with various epithets. Major species include P. malaanonan and P. tomentella. The sapwood is paler in colour and not clearly defined from the heartwood, which is pinkish cream when fresh, turning to straw-colour or light brown on exposure.

Also known as White Seraya (Brunei); Pendan, Penden, Tembalun and Urat mata (Indonesia); and Bagtikan, Light Red Philippines, Mahogany, Malaanonang and White lauan (Philippines).


DENSITY

The timber is a Light Hardwood with a density of 400-655 kg/m3 air dry.


NATURAL DURABILITY

It is non-durable.


PRESERVATIVE TREATMENT

The timber is difficult to treat with preservatives.


TEXTURE

Texture is moderately coarse and even with interlocked grain.


STRENGTH PROPERTIES

The timber falls into Strength Group C (Burgess, 1958).


MACHINING PROPERTIES

It is fairly easy to work although it has a dulling effect on the tools. The planed surface of tangential boards is smooth, but on the radial boards, there is a tendency for tearing of grain.


AIR DRYING

The timber dries moderately slowly to slowly and is subject to warping and checking and also staining by fungi. 25 mm thick boards take approximately 5.5 months to air dry.


KILN-DRYING

Kiln Schedule J is recommended. The timber is reported to season fairly rapidly with minimum defects except for some cupping.


Kiln Schedule J

Moisture Content (%)

Temperature (Dry Bulb)

Temperature (Wet Bulb)

Relative Humidity (%) (approx.)

F

C

F

C

Green

135

57.0

123

50.5

70

50

135

57.0

119

48.0

60

40

140

60.0

118

47.5

50

30

150

65.5

121

49.0

40

20

170

76.5

127

53.0

30


SHRINKAGE

Shrinkage is high, especially in the tangential direction. Radial shrinkage averages 2.5%, while tangential shrinkage averages 5.3%.


USES

The timber is suitable for interior finishing, panelling, partitioning, plywood, furniture, mouldings, skirtings and light constructional works. It has also been successfully tried for hardboard manufacture.


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. Menon, P. K. B. 1986. Uses of Some Malaysian Timbers. Revised by Lim, S. C. Timber Trade Leaflet No. 31. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 48 pp.
  3. Wong, T. M. 1982. A Dictionary of Malaysian Timbers. Revised by Lim, S. C. & Chung, R. C. K. Malayan Forest Records No. 30. Forest Research Institute Malaysia, Kuala Lumpur. 201 pp.