Mata Ulat Wood

 

#### *Introduction*

 

Mata Ulat is the Standard Malaysian Name for the wood derived from the *Kokoona* species, belonging to the Celastraceae family. This wood is commonly known by various vernacular names such as *bajan* in Sarawak and *perupok* in Peninsular Malaysia, with the latter also referred to as *perupok kuning* in Sabah. These species were historically grouped with *Lophopetalum* in older Malaysian literature. The major species of Kokoona include *K. littoralis, **K. ochraceae, **K. ovata-lanceolata, and **K. reflexa*. The sapwood is lighter in color and gradually transitions into the heartwood, which ranges from whitish to yellow-brown.

 

Additionally, Mata Ulat wood is known as *Sepali* in Indonesia and *Laying* in the Philippines.

 

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#### *Density*

 

Mata Ulat is classified as a Medium Hardwood, with an air-dry density ranging between *895 to 1,055 kg/m³*.

 

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#### *Natural Durability*

 

According to a study by Jackson (1965) involving *48 pieces of K. reflexa, all specimens were destroyed within 5 years, with an average lifespan of **4.2 years. As a result, Mata Ulat wood is considered **moderately durable. However, it is **not resistant* to subterranean termites, and sawn wood may be prone to attacks by powder-post beetles and sap-staining fungi.

 

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#### *Preservative Treatment*

 

Mata Ulat wood is *very difficult* to treat with preservatives, making it a challenge to enhance its natural durability.

 

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#### *Texture and Grain*

 

The texture of Mata Ulat wood is *fine* but uneven due to the presence of thick bands of parenchyma. The wood grain is *interlocked*, adding to the wood’s complexity during processing.

 

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#### *Strength Properties*

 

Mata Ulat wood is classified under *Strength Group A* (Engku, 1988b) or *SG 2* (MS 544: Part 2: 2001). Below are the detailed strength properties of *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                  |

 

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#### *Machining Properties*

 

Mata Ulat wood is relatively *easy to resaw and cross-cut*. When planed, the surface is smooth in the tangential direction, but slightly rough in the radial direction due to some grain pick-up.

 

| Test Condition | Sawing | Planing | Boring | Turning |

|—————-|——–|———|——–|———|

| Re-sawing      | Easy   | Easy    | Easy   | –       |

| Cross-Cutting  | Easy   | Easy    | Easy   | –       |

| Air Dry        | Easy   | Easy    | Easy   | Difficult (Rough Finish) |

 

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#### *Air Drying*

 

Mata Ulat wood exhibits the following air-drying characteristics:

 

| Species        | Time to Air Dry (months) | Remarks |

|—————-|————————–|———|

| 13 mm thick    | 3 months                 | Fairly slow drying; slight splitting; moderate end-checking and surface-checking; insect attacks. |

| 38 mm thick    | 5 months                 | Fairly rapid drying; slight end-checking, splitting, and surface-checking. |

 

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#### *Kiln-Drying*

 

*Kiln Schedule C* is recommended for Mata Ulat wood. 25 mm thick boards take approximately *10 days* to dry.

 

| Moisture Content (%) | Temperature (Dry Bulb) °F | Temperature (Wet Bulb) °F | Relative Humidity (%) |

|———————-|—————————|—————————-|————————|

| Green                | 105 (40.5°C)              | 101 (38.0°C)               | 85%                    |

| 60                   | 105 (40.5°C)              | 99 (37.0°C)                | 80%                    |

| 40                   | 110 (43.5°C)              | 102 (39.0°C)               | 75%                    |

| 35                   | 110 (43.5°C)              | 100 (38.0°C)               | 70%                    |

| 30                   | 115 (46.0°C)              | 103 (39.5°C)               | 65%                    |

| 25                   | 125 (51.5°C)              | 109 (43.0°C)               | 60%                    |

| 20                   | 140 (60.0°C)              | 118 (47.5°C)               | 50%                    |

| 15                   | 150 (65.5°C)              | 121 (49.0°C)               | 40%                    |

 

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#### *Shrinkage*

 

Shrinkage characteristics for Mata Ulat wood are summarized as follows:

 

| Species    | Radial Shrinkage (%) | Tangential Shrinkage (%) | Remarks |

|————|———————-|————————–|———|

| K. littoralis | 2.6                  | 3                        | Fairly high shrinkage. |

| K. reflexa   | 1.6                  | 2                        | Average shrinkage.    |

 

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#### *Defects*

 

Mata Ulat logs are generally *free from defects. However, during storage, issues such as end-splitting and checking may occur. The sapwood is particularly vulnerable to **powder-post beetle attacks*.

 

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#### *Uses*

 

Mata Ulat wood is versatile and suitable for a range of applications, particularly in heavy construction when treated. Some common uses include:

 

– *Posts, Beams, Joists, Rafters*

– *Bridges and Railway Sleepers*

– *Heavy-duty and Decorative Furniture*

– *Fender Supports*

– *Telegraphic and Power Transmission Posts*

– *Flooring (Heavy Traffic)*

– *Door and Window Frames*

– *Staircase Components*

– *Joinery and Cabinet Making*

– *Tool Handles (Impact)*

– *Vehicle Bodies (Framework and Floorboards)*

 

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