Properties and Specification
Empress Splendor tree
Paulownia, Empress Splendor, Empress, Kiri
Paulownia Elongata, Paulownia Fortunei
Native to eastern Asia with the oldest fossils discovered in North America
30-65 ft (10-20 m) tall, 2-4 ft (.6-1.2 m) trunk diameter
Heartwood typically a pale brown, sometimes with a reddish or purplish hue. Pale white sapwood not clearly demarcated from heartwood.
Reported to be durable regarding decay resistance and decent weathering characteristics.
Given its straight grain and lightweight, Paulownia is extremely easy to work. Takes a wide variety of glues, stains, and finishes well.
No characteristic odor.
Besides the standard health risks associated with any type of wood dust, no further health reactions have been associated with Paulownia.
Plywood, veneer, furniture, boxes, millwork/siding, musical instruments (electric guitar bodies), clogs, carvings, watercraft, and other specialty items.
- Empress wood is about 2/3 the weight of the lightest commercial wood grown in the US.
- It weighs an average of 14 to 19 lbs per cubic foot.
- It is almost 1/3 the weight of Oak (44 lbs p/cubic ft) and half the weight of Pine (30 lbs p/cubic ft).
- It has one of the highest strength to weight ratios of any wood.
- Empress wood has been widely used in the orient for fine furniture, musical instruments, carvings, and decorative finishes for over 1000 years.
- It can be peeled for veneer in 1/16 – 1/32 inch thickness.
- Intricate patterns can be cut with a jig saw or band saw without splitting easily and has been a favorite for many carvers in the US.
- Furniture, doors, and windows can be made with close tolerances.
- All normal finishing materials can be applied and it bonds well with glue.
- Air-drying takes as little as 30 days. Boards can be kiln dried at high temperatures in as little as hours to 10% moisture content with no warping.
- Reported shrinkage from green to oven-dry is only 2.2% radial and 4.0% tangential. It remains stable during changes in humidity and experiences little shrinkage or expansion compared to most other woods.
- It is highly durable and resists decay under non-ground contact conditions.
- The wood is insect resistant, as well as more fire resistant due to the moisture content of the tree during growth.
- Empress log homes are said to have twice the R factor as pine or oak logs and are a very good insulator.
- This temperature resistance also serves to give the wood a high fire resistance.
- Ignition temperature for Empress Wood is approximately 420 – 430 degrees Celsius (Other hardwoods ignite at 220-225 degrees Celsius).
Density @10% moisture content: 14.37 – 18.75 lbs/cuft
Density @10% moisture content: 18.17 lbs/cuft
Density @ oven dried: 17.11 lbs/cuft
Alpha-Cellulose content: 40.72%; 38.50%-41.46%
Pentosan: 24.78%; 20.56%-25.35%
Lignin content: 20.87%; 21.24%-24.28%
Leaves: ursolic acid, C30H4803; matteucinol, C18H1805
Xylem: Paulownium, C20H18O7@CH3OH; d-Sesamin
Bark: syringin, C17H24O9@H2O; Catapinoside
Bending & Compression Properties
Modulus of rupture (mor): 5420-5740 psi
Modulus of elasticity (moe) x 10 to 6th: 0.735-0.758 psi
Compression parallel to grain: 2800-3560 psi
Compression perpendicular to grain: 300-440 psi
Shear parallel to grain: 800-1150 psi
BTU (British thermal unit)
7600-8400 per pound
Janka Hardness Scale: 260-290
Shrinkage Coefficient (%)
Specific gravity: 0.251 – 0.274 (23 to 30% of the density of water)
Specific gravity @ 10% MC: 0.265
Radial: 1.1 – 2.7
Tangential: 2.1 – 4.9
Green to Oven Dry: 5.9
(92% Relative Humidity @ 20 degrees C)
1-day; 2-day; maximum
12%; 15%; 19%