Mempisang wood

Mempisang

INTRODUCTION

The Standard Malaysian Name for the timber of the family Annonaceae. Vernacular names applied include akau (Sarawak), antoi (Peninsular Malaysia), jangkang (Peninsular Malaysia), karai (Sabah and Sarawak) with various epithets, kepayang babi (Sarawak), mangitan (Peninsular Malaysia), manitan (Peninsular Malaysia) and pisang-pisang (Peninsular Malaysia and Sabah). Major species include Alphonsea curtisii, A. elliptica, A. johorensis, A. maingayi; Cyathocalyx pruniferus, C. sumatranus; Mezzettia parviflora; Mitrephora maingayi, M. vulpina; Monocarpia euneura; Platymita siamensis; Polyalthia glauca, P. hypoleuca, P. sclerophylla, P. sumatrana; Xylopia ferruginea, X. fusca and X. stenopetala. The sapwood is normally not differentiated from the heartwood, which is light yellow-white or light yellow-brown, often with a green tinge.

Also known as Mempisang (Brunei); Mako (Fiji); Debdaru, Gauri and Nedunar (India); Banitan putih, Jongkong, Kepayong babi, Langolia maeto, Loera poete, Mahabai, Mandjat, Oenrolia wone, Salak, Semukau padi, Suluh, Tapal madu, Tepis and Uras lemah (Indonesia); Taw and Tawsagasein (Myanmar); Bolon, Dalinas, Kalai and Yellow Lanutan (Philippines); Netawa (Sri Lanka); and An-phong (Vietnam).

DENSITY

The timber is a Light Hardwood with a density of 370-975 kg/m³ air dry, although the majority of the timbers fall within the range of 515-720 kg/m³ air dry.

NATURAL DURABILITY

Mempisang has been classified as non-durable under exposed conditions in Malaysia (Wong, 1982). The above classification is mainly based on the findings by Jackson (1965) who tested the timber Monocarpia marginalis (formerly known as Cyathocalyx maingayi) under natural conditions and the timber was completely destroyed in slightly more than a year. Mohd. Dahlan et. al., (1987) tested the natural durability of three species of mempisang, namely Monocarpia marginalis, Xylopia fusca and Mezzettia leptopoda and they were found to be not durable. Desch (1957) reported that in Sumatra, the timber of Mezzettia leptopoda or a related species, when used for planks under cover or protected from rain are fairly durable. In India, Pearson et al. (1932) described the timber of Polyalthia as fairly durable for internal work and not very susceptible to insect and fungal attacks.

PRESERVATIVE TREATMENT

The timber is very amenable to preservative treatment.

TEXTURE

Texture is rather coarse and uneven due to the presence of the extremely large rays.

STRENGTH PROPERTIES

The timber falls into Strength Group C (Engku, 1988b) or SG 5 (MS 544:Part 2:2001).

Strength Properties of Mempisang  

MACHINING PROPERTIES

The timber is easy to work and plane and the surface produced may not be perfectly smooth. Boring is easy but the surface obtained may be rough. Turning is easy and a smooth finish may be achieved.

Machining Properties of Mempisang (M. marginalis) 

NAILING PROPERTY

The nailing property is rated as poor.

AIR DRYING

The seasoning properties of the timber vary according to the species and are summarised below:

KILN-DRYING

Kiln Schedule H is recommended. However, the schedule is based on the test carried out on the species of Mezzettia parviflora, the density of which is about 670 kg/m³ air dry. When dealing with the heavier varieties of mempisang, e.g. Alphonsea elliptica (density: 975 kg/m³) and Polyalthia rumphii (density; 805-815 kg/m³), due care should be taken to use a milder schedule to prevent the occurence of drying defects.

Kiln Schedule H

SHRINKAGE

The shrinkage of some species is summarised below: 

USES

The timber is suitable for general light construction, plywood, pencil, match boxes and splints, ornamental items, bentwood, packing cases and crates. The heavier species can be used for flooring, joists (light construction), railway sleepers, ship and boat building (masts, spars, oars and helms), tool handles (non impact) and cooling tower (non-structural).