Natural fibres were the first fibres used for thermoset reinforcement and are always used in phenolic resins whose consumption is declining for environmental problems principally due to recycling difficulties. Thanks to excellent ratios [cost/performance], glass fibres are, by far, the most consumed with a market share of 95 % but numerous other fibres can be used.
Now, there is a renewed interest for natural fibres for several reasons:
* Sustainability: apart wood, their origin is in fast growing plants. Even for wood, renewing duration is far shorter than the fossil energy used for glass fibre production.
* Geopolitics motivations: many plants grow in developing countries and need agricultural means instead of industrial ones.
* Environmental motivations: the production of natural fibres saves energy and decreases pollution. Now, ecology is a buoyant marketing argument.
One must distinguish:
* The origin,
* The nature,
* The form of natural fibres .
The origin of natural fibres used in polymers is principally in plants and trees.