Milk Tree

Overview

Milk Tree is a magnificent deciduous tree of the forest canopy, often 20 to 40 metres tall with a dome shaped crown. The tree yields a lightweight hardwood with density of 380-420 kilograms per cubic metre. As the wood peels very easily and evenly, it is commonly used for veneer production.

Milk Tree is used for high structural, boat building, cabinet and furniture, joinery, mouldings and panelling, fruit cases and light framing. It is also said to slice into attractive, quartered striped veneers for decorative applications.

Botanical Name: Antiaris toxicaria.
Standard Trade Names: Milk Tree.
Other Names: Melektri (Vanuatu) Bark Cloth Tree (U.K) upas (Philippines).
Origin of Product:
Grade:
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Species information for this product:
  • The timber has wide sapwood that is not clearly demarcated from the heartwood, which is usually white but may be brownish. There is a distinct ribbon figure on quarter-sawn faces. The grain may be straight to interlocked, but is typically moderately interlocked. Annual rings are usually not discernible since the tree is reported to grow evenly all year round.

  • Trees must be converted rapidly after felling to avoid deterioration and must be protected against blue stain. It seasons readily and quickly. Kilning gives best results, with minimal warping and splitting. There is moderate shrinkage upon seasoning but it is very stable after seasoning.

  • Can be worked fairly easily with hand and machine tools, but cutting edges must be very sharp to avoid tearing and crumbling. The dust from Milk Tree is toxic because of the latex that is present, causing dermatitis and stomach pains.

Names
Family: Moraceae.
Species: Antiaris toxicaria.

Properties

Properties
Density: 380-420 Kg/m3 @ 12% m.c
Durability: Class 4: Non-durable.
Colour: White and sometimes can be brownish.
Texture: Even medium to coarse.
Grain: Interlocked and wavy.
Figure: Lustrous, ribbon figure on quarter-sawn faces.
Permeability: Class 1: Permeable to pressure impregnation.
Workability
General: Very soft and easy to work with if blades are kept sharp.
Sawing: Saws easily but is slightly gummy because of latex
Planing: Planing requires a cutting angle of 20 degrees to prevent interlocked grain from tearing out.
Blunting: Low.
Boring: The wood is fairly difficult to bore because of interlocked grain and soft fibrous tissue. Support is required to prevent break-out as tool exits.
Turning:
Nailing: Nails satisfactorily.
Gluing: Glues well.
Finishing: Polishes well, accepts stain and paint satisfactorily.

Mechanical

Mechanical Properties
Strength: SD8.
Structural Grade: F11 (select grade seasoned).
Hardness (Janka): 3.8kN (seasoned), 2.7kN (unseasoned).
Max. Crushing Strength: 46MPa (seasoned), 25Mpa (unseasoned).
Modulus of Elasticity: 12GPa (seasoned), 9.7GPa (unseasoned).
Modulus of Rupture: 85MPa (seasoned), 49MPa (unseasoned).
Seasoning
General: Seasons rapidly.
Movement: Very low.
Shrinkage: Low.