Bamboo

0.5-3 usd/kg
Circularity potential
Very high
Strength
High
Production energy
Ultra low
Stiffness
Medium
Embodied CO2
Ultra low
Density
Low

Bamboo is classified as a type of grass and its stem is converted into timber products, paper, fibres and textiles. In addition, the woody tissue, like that of tree trunks, provides the feedstock for cellulose based plastics and fibres, such as viscose and cellulose acetate (CA). It grows around the world in a variety of climates, from cold mountainous regions to tropical areas, and is available from sustainably managed sources. It’s speed of growth and ease of harvesting means it can be very cost-effective.

Bamboo contains many of the same ingredients as wood: it is a natural composite made up of polysaccharides (cellulose and hemicellulose) and lignin. However, bamboo grows differently, with a denser packing of the cellulose fibres towards the outside of its hollow stem. This naturally optimised structure is far more efficient in terms of strength-to-weight than a solid rod-like tree trunk. This allows bamboo to grow very fast, while remaining lightweight and resistant to wind and other natural forces. It is suitable for structural uses after 3-5 years of growth.

The drawbacks of bamboo, other than natural variation, are its vulnerability to water absorption and decay. Bamboo is perishable and will last only a short time outdoors without suitable treatment. Additionally, the rich starch content provides a source of food for insects and fungus. To counter this, bamboo is impregnated with chemicals, which affects its sustainability.



Bamboo bast fibre (like jute, hemp, ramie) is made by splitting the stem to separate the woody part into long and flexible strands. It is strong and flexible and used in basketmaking, lighting, furniture and packaging. More recently, it has been explored as a fibre reinforcement for high performance composites and concrete.

While the bast fibre has some advantageous properties, it is not suitable for soft fabrics, such as used in garments. To make a soft fibre, the bamboo is ground up and chemically processed into viscose or cellulose acetate (CA). It is the same process as used for wood and cotton. The only difference is bamboo provides the raw material – ultimately, the fibre will have the same properties as one produced from another cellulose containing material.


Design properties
Cost usd/kg
2-8
Embodied energy MJ/kg
0.5-1
Carbon footprint kgCO2e/kg
0.2
Density kg/m3
800
Tensile modulus GPa
32-55
Tensile strength MPa
550-1690
Hardness Mohs
1.5
Thermal conductivity W/mK
0.1-1.8
Temperature min-max °C
-200 to 150
Thermal
insulator
Electrical
insulator