Coir fiber / Coconut fiber Definition : Definitions for the Clothing & fabric Industry

Processing

Green coconuts, harvested after about six to twelve months on the plant, contain pliable white fibers. Brown fiber is obtained by harvesting fully mature coconuts when the nutritious layer surrounding the seed is ready to be processed into copra and desiccated coconut. The fibrous layer of the fruit is then separated from the hard shell (manually) by driving the fruit down onto a spike to split it(De-husking). Machines are now available which crush the whole fruit to give the loose fibers.

Brown fiber: The fibrous husks are soaked in pits or in nets in a slow moving body of water to swell and soften the fibers. The long bristle fibers are separated from the shorter mattress fibers underneath the skin of the nut, a process known as wet-milling. The mattress fibers are sifted to remove dirt and other rubbish, dried and packed into bales. Some mattress fiber is allowed to retain more moisture so that it retains its elasticity for 'twisted' fiber production. The coir fiber is elastic enough to twist without breaking and it holds a curl as though permanently waved. Twisting is done by simply making a rope of the hank of fiber and twisting it using a machine or by hand. The longer bristle fiber is washed in clean water and then dried before being tied into bundles or hunks. It may then be cleaned and 'hackled' by steel combs to straighten the fibers and remove any shorter fiber pieces. Coir bristle fiber can also be bleached and dyed to obtain hanks of different colors.

White fiber: The immature husks are suspended in a river or water-filled pit for up to ten months. During this time micro-organisms break down the plant tissues surrounding the fibers to loosen them - a process known as retting. Segments of the husk are then beaten by hand to separate out the long fibers which are subsequently dried and cleaned. Cleaned fiber is ready for spinning into yarn using a simple one-handed system or a spinning wheel.

Uses

Brown coir is used in brushes, doormats, mattresses and sacking. A small amount is also made into twine. Pads of curled brown coir fiber, made by needle-felting (a machine technique that mats the fibers together) are shaped and cut to fill mattresses and for use in erosion control on river banks and hillsides. A major proportion of brown coir pads are sprayed with rubber latex which bonds the fibers together (rubberized coir) to be used as upholstery padding for the automobile industry in Europe. The material is also used for insulation and packaging. The major use of white coir is in rope manufacture. Mats of woven coir fiber are made from the finer grades of bristle and white fiber using hand or mechanical looms.

Coir is recommended as substitute for milled peat moss because it is free of bacteria and fungal spores.