Nyalin


INTRODUCTION

The Standard Malaysian Name, which is of Sarawakian origin, for the timber of Xanthophyllum spp. (Polygalaceae). The ASEAN Standard Name, which is of Indonesian origin, for the timber is LILIN. Vernacular names applied include mengkapas (Peninsular Malaysia) and minyak berok (Peninsular Malaysia and Sabah). Major species include X. affine, X. amoenum, X. obscurum and X. stipitatum. The sapwood is not differentiated from the heartwood, which is white to bright yellow when fresh and darkens to a strong orange-yellow.

Also known as Gading, Gading batu, Lilin, Medang tanduk, Mendjalin and Minat angkat (Indonesia); Seng (Laos); Kam-gaw (Myanmar); Box wood (Papua New Guinea); Bok-bok and Malatadiang (Philippines); Chumsaeng, Khangkhao and Saeng (Thailand); and Sang ot (Vietnam).


DENSITY

The timber is hard to very hard and heavy to very heavy with a density of 595-960 kg/m3 air dry. The timber is classified under Medium Hardwood in Malaysia.


NATURAL DURABILITY

The timber is non-durable under exposed conditions and is also susceptible to drywood termites.


TEXTURE

Texture is moderately coarse to coarse and uneven. Grain is straight, sometimes wavy.


STRENGTH PROPERTIES

The timber falls into Strength Group B (Engku, 1988b) or SG 4 (MS 544:Part 2:2001).


MACHINING PROPERTIES

It is easy to saw and works well and the planed surface is moderately smooth.


NAILING PROPERTY

The nailing property is rated as good.


AIR DRYING

The timber seasons moderately slowly with only slight defects like cupping, bowing and end-checking. The timber is, however, subject to insect attacks during seasoning. 13 mm thick boards require 4 months to air dry, while 38 mm thick boards take 5 months.


SHRINKAGE

Shrinkage is very high, especially in the tangential direction. Radial shrinkage averages 2.6% while tangential shrinkage averages 4.9%.


USES

The timber is suitable for medium and heavy construction, which is temporary or protected from attacks by drywood termites. It is also suitable for panelling, mouldings, flooring (heavy traffic), joists, staircase (angle block, rough bracket, newel, riser, tread, bullnose, round end and winder), planking, plywood, tool handles (impact) and pallets (permanent and heavy duty). When treated, it is suitable for telegraphic and power transmission posts and cross arms. The timber has also been successfully used for the manufacture of blockboards.


REFERENCES

  1. 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.
  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. MS 544:Part 2:2001. Code of Practice for the Structural Use of Timber: Permissible Stress Design of Solid Timber.
  4. 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.