What is coir?
Coir is a coarse fibre obtained from the tissues surrounding the seed of the
coconut palm,
Cocos nucifera. The intact fruit has a smooth leathery skin above the thick fibrous layer. This surrounds the stony dark brown shell, which is actually part of the fruit rather than the seed. Inside the shell are the papery brown outer layer of the seed surrounding the nutritious white flesh and the embryo.
The fibrous layer forms a strong, shock-absorbing mesh which protects the seed from mechanical damage and is water-resistant. The individual fibre cells are narrow and hollow, with thick walls made of cellulose. They are pale when immature but later they become hardened and yellowed when a layer of lignin, a complex woody chemical, is deposited on their walls. Mature brown coir fibres contain more lignin and less cellulose than fibres such as flax and cotton and so are stronger but less flexible. White fibre is smoother and finer than the harder brown fibre but is also weaker. The coir fibre is relatively water-proof and is the only natural fibre resistant to damage by salt water.
