Composites World published a helpful article in January of this year titled “The Fiber” In it, they detail various attributes of any fiber that you could choose to make up your composite. They include a nice section about Natural Fibers, detailing the reasons why they could be the best choice for a particular application.
The article states:
“Natural fibers — abaca, coconut, flax, hemp, jute, kenaf and sisal are the most common — are derived from the bast or outer stem of certain plants. Natural fibers are enjoying increased use because of their “green” attributes (less energy to produce), light weight, recyclability, good insulation properties and carbon dioxide neutrality (when burned, natural fibers give off no more carbon dioxide than was consumed to grow the source plant). They also have the lowest density of any structural fiber but possess sufficient stiffness and strength for some applications.
The automotive industry, in particular, is using these fibers in traditionally unreinforced plastic parts and even employs them as an alternative to glass fibers. Natural fiber-reinforced thermosets and thermoplastics are most often found in door panels, package trays, seat backs and trunk liners in cars and trucks. European fabricators hold the lead in use of these materials, in part because regulations now require their automobile components to be recyclable. Natural fibers can be incorporated into molded or extruded parts and, more recently, have been used in the direct long fiber injection (D-LFT) process where kenaf, flax and natural fiber/glass hybrids are used to reinforce polypropylene. Studies are underway to determine the suitability of long natural fiber composites for structural applications.”