Coir: One of the Strongest Natural Fibers

Coir, originally just considered a byproduct of the coconut industry, has become increasingly popular for its use as a strong natural fiber. It is used in a number of industries, from food textiles, to agricultural crops, to building materials, and beyond. It is notably strong as a plant fiber and even competes with animal fibers. 

Coir Fiber

It is possible to harvest 10 kilograms of coir fibers from 1,000 coconuts. These fibers can measure up to 35 centimeters in length and 12-25 microns in diameter. Among plant fibers, coir has the highest concentration of lignin–mature coir fibers contain even higher levels of lignin–which gives it its strength. 

Other Types of Natural Fiber

To fully understand the strength of coir as a fiber, it helps to compare it to other options on the market. This range includes plant fibers, such as cotton, seed hairs, flax, hemp, sisal, and husk fiber; and animal fibers, such as wool, hair, and silk. Of the plant fibers, coir has one of the highest concentrations of the substance lignin. This makes it stronger, but also less flexible, than cotton. Other plant fibers, including ramie, flax, hemp, and sisal, contain significantly less lignin. In general, coir is the thickest and most resistant of the commercially available natural fibers.

Compared with abaca, coir has less tensile strength. This is overcome by coir’s resistance to microbial action and salt water damage. It also needs no chemical treatment, which adds to its appeal as a gardening, building, and textile commodity. 

Uses in Industry

When combined with resin and pretreated timber veneers, coir becomes a substitute for plywood. Coir provides strength and stability for this use. This product has been tested in developing countries as a timber alternative, as it is both cost and environmentally friendly. It has also been mixed into concrete to improve cost-effectiveness, compression strength, tensile strength, and longevity. 

White coir is spun into yarn and used in the manufacture of rope, fishing nets, rugs, and other commodities. Brown coir is even more commonly used than white coir and can be found in brushes, doormats, mattresses, insulation, and packaging materials. 

Coir is also used in the geotextile industry for its low decomposition rate and high strength compared to other natural fibers. In erosion-prone areas, mats made of woven coir are applied like blankets on the ground. Textiles made from this fiber are durable, sunlight resistant, water absorbent, biodegradable, and facilitate seed germination. 

Combined with natural rubber, coir is a healthy substitute for synthetic rubber. It has been used to fill mattresses, car seats, sofas, and other seating systems. Coir rubber is also used as insulation in the food industry.

Coir is one of the strongest natural fibers on the market. It is also the thickest and most resistant of all commercial natural fibers. Originally considered just a byproduct of coconut production, coir fibers are finding their way into many industries throughout the world. With millions of acres committed to coconut groves, the sustainable use of this resource is positive and beneficial to many industries.