Punah


INTRODUCTION

The Standard Malaysian Name for the timber of Tetramerista spp. (Tetrameristaceae). Vernacular names applied include entuyut (Sarawak), kayu chelega (Sarawak), kayu hujan (Sarawak), kayu tangiran (Sarawak), samondu (Sabah), suyut (Sabah), tuyot (Sabah) and tuyut (Sabah). Only one species is of importance in this country, viz. T. glabra. The sapwood is lighter in colour and not always clearly defined from the heartwood, which is pink-brown, weathering to light brown.

Also known as Amat (Brunei); and Bangkalis, Carega, Kayu malaka and Punak (Indonesia).


DENSITY

The timber is a Medium Hardwood with a density of 625-800 kg/m3 air dry.


NATURAL DURABILITY

This timber is moderately durable. Graveyard tests indicated that the test specimens had an average life of 3.8 years (Jackson, 1960). Another test completed in 1980 indicated an average service life of 2.8 years. A service test on punah sleepers was carried out in 1949 (Ong, 1971), where 234 sleepers were treated by the open tank method using 50/50 Creosote/Diesel fuel mixture. Absorption was between 63 kg/m3 and 68.56 kg/m3 (3.9 to 4.3 lb/ft3). Service life of the sleepers averaged 19.5 years.  


PRESERVATIVE TREATMENT

Its amenability to preservative treatment is classified as average.


TEXTURE

Texture is moderately coarse but even, with straight, interlocked and sometimes spiral grain.


STRENGTH PROPERTIES

The timber falls into Strength Group B (Engku, 1988b) or SG4 (MS 544:Part 2:2001).


Strength Properties of Punah

Test Condition

Modulus of Elasticity(MPa)

Modulus of Rupture(MPa)

Compression parallel to grain (MPa)

Compression perpendicular to grain (MPa)

Shear Strength (MPa)

Green

13,500

86.0

34.5

4.21

8.9

Air dry

15,400

87.0

48.4

5.72

9.7

  
MACHINING PROPERTIES

It is easy to saw and work. Planing is easy although the surface produced is only moderately smooth to rough.


Machining Properties of Punah
 

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

rough

easy

smooth

-

-

Air dry

easy

easy

easy

moderately smooth

easy

smooth

easy

rough


NAILING PROPERTY

The nailing property is rated as good.


AIR DRYING

The timber dries moderately fast but is prone to a large amount of seasoning degrade like bowing, end-checking, splitting, surface-checking and staining. 13 mm thick boards take approximately 2.5 months to air dry, while 38 mm thick boards take 4 months.


KILN-DRYING

Kiln Schedule C is recommended. The timber dries fast without much degrade, except for thicker sections, which are prone to surface-checking and end-splitting. 25 mm thick boards take approximately 7 days to kiln-dry from 50 to 10% moisture content.


Kiln Schedule C

Moisture Content (%)

Temperature
(Dry Bulb)

Temperature
(Wet Bulb)

Relative Humidity (%)

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

Shrinkage is very high, with radial shrinkage averaging 3.2% and tangential shrinkage averaging 4.5%.


DEFECTS

This timber is normally free from defects, but some ambrosia-beetle attacks have been noted in some punah timber. Severe heart shakes have been recorded (Thomas, 1950).


USES

The timber is suitable for all forms of heavy construction under cover, posts, beams, joists, rafters, heavy duty and general furniture, flooring (heavy traffic), piling, columns (light duty), railway sleepers (treated), vehicle bodies (framework, floor boards and planking), piling, door and window frames and sills, staircase (baluster, handrail, newel and sprandrel framing), joinery, cabinet making, cooling tower (structural members) as well as telegraphic and power transmission posts and cross arms.


REFERENCES

  1. Engku, Abdul Rahman Chik. 1988b. Basic And Grade Stresses For Some Malaysian Timbers. Malayan Forest Service Trade Leaflet No. 38. The Malaysian Timber Industry Board And Forest Research Institute Malaysia, Kuala Lumpur. 13 pp.
  2. Jackson, W. F. 1960. The Durability of Malayan Timbers. Malay. For. Ser. Trade Leaflet No.28.
  3. Lopez, D. T. 1982. Malaysian Timbers - Punah. Malaysian Forest Service Trade Leaflet No. 59. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 6 pp.
  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 Insitute Malaysia, Kuala Lumpur. 48 pp.
  5. MS 544: Part 2: 2001: Code Of Practice For Structural Use Of Timber. Permissible Stress Design of Solid Timber.
  6. Ong, T. H. 1971. Service Test on Punah Sleepers. Malay. For.Vol.34 No.4.
  7. Thomas, A. V. 1950. Malayan Timbers - Mengkulang, Mersawa, Punah. Malay. For. Ser. Trade Leaflet No.11.
  8. 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.