Mata Ulat


INTRODUCTION

The Standard Malaysian Name for the timber of Kokoona spp. (Celastraceae). Vernacular names applied include bajan (Sarawak) and perupok (Peninsular Malaysia) in older Malaysian literature, when the species were grouped together with those of Lophopetalum and also perupok kuning (Sabah). Major species include K. littoralis, K. ochraceae, K. ovata-lanceolata and K. reflexa. The sapwood is lighter in colour and merges gradually into the heartwood, which is whitish to yellow-brown.

Also known as Sepali (Indonesia) and Laying (Philippines).


DENSITY

The timber is a Medium Hardwood with a density of 895-1,055 kg/m3 air dry.


NATURAL DURABILITY

Jackson (1965) reported on a trial involving 48 pieces of K. reflexa. All specimens were destroyed witthin 5 years and gave an average life span of 4.2 years. The timber is thus classified as moderately durable. The timber is not resistant to subterranean termites. Sawn timbers have also been attacked by both powder-post beetles and sap-staining fungi.      


PRESERVATIVE TREATMENT

The timber is very difficult to treat with preservatives.   


TEXTURE

Texture is fine but uneven due to the thick bands of parenchyma. Grain is interlocked.


STRENGTH PROPERTIES

The timber falls into Strength Group A (Engku, 1988b) or SG 2 (MS 544:Part 2:2001).


Strength Properties of Mata Ulat (K. littoralis

 Test Condition

Modulus of Elasticity(MPa)

Modulus of Rupture(MPa)

Compression parallel to grain (MPa)

Compression perpendicular to grain (MPa)

Shear strength (MPa)

Green

16,300

102

53.1

6.8

10.7


MACHINING PROPERTIES

It is easy to resaw and cross-cut. Planing is easy and the planed surface is smooth in the tangential direction but slightly rough due to some grain pick-up in the radial direction.


Machining Properties of Mata Ulat (K. littoralis)
  

Test Condition

Sawing

Planing

Boring

Turning

Re-sawing

Cross Cutting

Ease of planing

Quality of finish

Ease of boring

Quality of finish

Ease of turning

Quality of finish

Green

easy

easy

easy

tangential: smooth; radial; some grain pick-up

easy

smooth

-

-

Air dry

easy

easy

easy

smooth

easy

smooth

difficult

rough


AIR DRYING

 The seasoning characteristics are summarired below:
 

Species

Time to air dry (months)

Remarks

13 mm thick boards

38 mm
thick boards

K. littoralis

3

5

Fairly slow drying; slight splitting; moderate end-checking and surface-checking; insect attacks.

K. reflexa

2

3.5

Fairly rapid drying; slight end-checking, splitting and surface-checking.

 

 

 

 

 



KILN-DRYING

Kiln Schedule C is recommended. 25 mm thick boards take approximately 10 days to dry.


Kiln Schedule C

Moisture Content (%)

Temperature (Dry Bulb)

Temperature (Wet Bulb)

Relative Humidity (%)(approx.)

F

C

F

C

Green

105

40.5

101

38.0

85

60

105

40.5

99

37.0

80

40

110

43.5

102

39.0

75

35

110

43.5

100

38.0

70

30

115

46.0

103

39.5

65

25

125

51.5

109

43.0

60

20

140

60.0

118

47.5

50

15

150

65.5

121

49.0

40


SHRINKAGE

The shrinkage is summarired below:

Species

Shrinkage (%) (Green to air dry)

Remarks

Radial

Tangential

K. littoralis

2.6

3

Fairly high shrinkage.

K. reflexa

1.6

2

Average shrinkage.

  

 

 



DEFECTS

The logs of mata ulat are remarkably free from defects. However, during storage, degrade in the form of end-splitting and checking may appear. The sapwood is liable to be attacked by powder-post beetles.  


USES

The timber is suitable for heavy construction if treated, e.g. posts, beams, joists, rafters, bridges and railway sleepers. The timber is also suitable for heavy duty and decorative furniture, fender supports, telegraphic and power transmission posts and cross arms, flooring (heavy traffic), door and window frames and sills, staircase (angle block, rough bracket, handrail and sprandrel framing), joinery, cabinet making, tool handles (impact) and vehicle bodies (framework and floor boards).


REFERENCES

  1. Desch, H. E. 1941. Manual of Malayan Timbers. Vol. 1. Mal. For. Rec. No. 15.
  2. Engku Abdul Rahman Chik. 1998b. Basic and Grade Stresses for Strength Groups of Malaysian Timbers. Malayan Forest Service Trade Leaflet No. 38. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 13 pp.
  3. Jackson, W. F. 1965. The Durability of Malayan Timbers. Mal. For. Ser. Trade Leaflet No. 28.
  4. 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.
  5. MS 544:Part 2:2001. Code of Practice for the Structural Use of Timber: Permissible Stress Design of Solid Timber.
  6. 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.
  7. Wong, T. M. 1982. Malaysian Timbers - Mata Ulat. Malaysian Forest Service Trade Leaflet No. 70. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 10 pp.