Use of Coir
Coir is a durable natural fiber extracted from the mesocarp tissue, or husk, of the coconut fruit. When cleaned after being separated from the coconut husk, the fiber often takes on a golden hue, earning it the nickname "The Golden Fibre."
Derived from the coconut shell's fibrous husk, coir is known for its strength and natural resistance to seawater. This resilience enables coconuts to drift across ocean currents for months, eventually landing on coastal shores where they may sprout and grow if fresh water is available—since the seed already carries the necessary nutrients.
These qualities make coir highly suitable for products such as floor and outdoor mats, aquarium filters, ropes, and garden mulch.
The global production of coir fiber stands at approximately 250,000 tonnes. This industry plays a significant role in several developing regions.
Structure of Coir Fibre
Coir fibre consists of individual cells that are narrow, hollow, and have thick cellulose walls. Initially pale in color, they harden and develop a yellow hue as lignin accumulates on their walls. Compared to flax and cotton fibers, mature brown coir fibers have a higher lignin content and lower cellulose levels, making them stronger but less flexible. These fibers are composed of tiny threads, each measuring less than 0.05 inches (1.3 mm) in length and with a diameter of 10 to 20 micrometers. White coir fiber is finer and smoother but not as strong.
One of the unique properties of coir fiber is its relative water resistance, making it the only natural fiber that is not easily damaged by salt water.
Green coconuts, harvested between six to twelve months of growth, produce pliable white fibers. In contrast, brown fiber is derived from fully mature coconuts, whose outer layer is ready for processing into copra and desiccated coconut. The fibrous husk is separated from the hard shell manually by driving the coconut onto a spike in a process called de-husking. However, modern machines now crush whole coconuts to extract loose fibers efficiently.
Brown Fibre
Fibrous coconut husks are soaked in water bodies such as pits or slow-moving streams to allow the fibers to swell and soften. The long bristle fibers are then separated from the shorter mattress fibers beneath the husk’s surface in a process called wet-milling. The mattress fibers are sifted to remove dirt and debris, dried, and compressed into bales. Some fibers retain more moisture to maintain elasticity for producing ‘twisted’ fiber. Coir fiber is naturally elastic, allowing it to be twisted without breaking while holding a curled shape, similar to a permanent wave.
Twisting is done by forming a rope from fiber hanks and twisting it either manually or with a machine. The longer bristle fibers are washed, dried, and bundled. They may then be processed through steel combs, known as hackling, to straighten them and remove shorter strands. Bristle fibers can also be bleached and dyed to create fiber hanks in various colors.
White Fibre
Immature coconut husks are submerged in water-filled pits or rivers for up to ten months. During this period, microorganisms break down the plant tissues surrounding the fibers, making them easier to extract—a process called retting. The husk segments are then beaten manually to separate the long fibers, which are later dried and cleaned. Once cleaned, the fiber is ready for spinning into yarn using either a simple hand-spinning method or a spinning wheel.
Uses / Applications
Brown coir is commonly used for making brushes, doormats, mattresses, and sacks, with a small portion also used for twine production. Pads made from curled brown coir fiber are shaped and cut for mattress filling and erosion control applications on riverbanks and hillsides. Many brown coir pads are treated with rubber latex, binding the fibers together (rubberized coir), which is widely used in Europe’s automobile upholstery industry. Additionally, coir is utilized for insulation and packaging.
White coir is mainly used for rope production. Finer grades of both bristle and white fiber are woven into mats using handlooms or mechanical looms. Coir is also considered a sustainable alternative to milled peat moss since it is free from bacteria and fungal spores.
Major Producers
Global coir fiber production stands at approximately 250,000 tonnes. The coir industry is especially significant in certain developing regions. India, particularly the coastal areas of Kerala, accounts for 60% of the world’s white coir fiber production. Sri Lanka, on the other hand, contributes to 36% of the global brown fiber output. More than half of the coir fiber produced worldwide is consumed in its country of origin, with India being the largest consumer.
Interesting Coir Facts
Coir is a highly versatile natural fiber extracted from the mesocarp tissue or husk of coconuts. The husk comprises 20% to 30% fiber of varying lengths. After grinding, the long fibers are separated and used in industrial applications such as rope and mat manufacturing. The remaining material, which includes shorter and medium-length fibers along with pith tissue, is referred to as waste-grade coir. This waste-grade coir can be further screened to remove fiber, leaving behind a product known as coir pith.