|By goGreen | August 2, 2011|
Coir is the fibrous material found between the hard, internal shell and the outer coat of a coconut. This is the only natural fibre resistant to damage by salt water.
Coir is a natural fibre extracted from the husk of coconut and used in products such as floor mats, doormats, brushes, mattresses, upholstery padding, sacking and horticulture. White coir is harvested from unripe coconuts, and is used for making finer brushes, string, rope and fishing nets. White coir is also spun into yarn and then twisted into rope or twine, or woven into cloth mats.
Brown Coir – the color of the material relates to the degree of ripeness when the coconut is harvested. Brown coir results when coconuts are harvested fully ripe. It is strong and very resistant to abrasion and sun damage.
White Coir – immature or green coconuts produce white coir, a finer but weaker fiber.
For brown coir – The fibrous husks are soaked in pits or in nets in a slow moving body of water to swell and soften the fibres. The long bristle fibres are separated from the shorter mattress fibres underneath the skin of the nut, a process known as wet-milling. The mattress fibres are sifted to remove dirt and other rubbish, dried in the sun and packed into bales. Some mattress fibre is allowed to retain more moisture so that it retains its elasticity for twisted fibre production. The coir fibre 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 fibre and twisting it using a machine or by hand. The longer bristle fibre 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 fibres and remove any shorter fibre pieces. Coir bristle fibre can also be bleached and dyed to obtain hanks of different colours.
For white coir – 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 fibres to loosen them — a process known as retting. Segments of the husk are then beaten by hand to separate out the long fibres which are subsequently dried and cleaned. Cleaned fibre is ready for spinning into yarn using a simple one-handed system or a spinning wheel.
Researchers at CSIR’s National Institute for Interdisciplinary Science and Technology NIIST) in Thiruvananthapuram have developed a biological process for the extraction of coir fibre from coconut husk without polluting the environment. The technology uses enzymes to separate the fibres by converting plant compounds into soluble compounds and hence curbs the pollution of water-bodies caused by retting of coconut husks.
Coir is a completely renewable and is an environmental friendly product. It can be dehydrated and easily stored until needed. Coconut fiber contains potassium and phosphorus, and has a near-neutral pH. Thus, best for growing a wide-range of plants.