Coconut fiber (coir fiber) Coconut fiber, obtained from unripe coconut, is a natural fiber extracted from the husk of coconut. The coconut is steeped in hot seawater, and subsequently, the fibers are removed from the shell by combing and crushing, the same process as jute fiber. The individual fiber cells are narrow and hollow with thick walls made of cellulose, and each cell is about 1 mm long and 10â??20 �¼m in diameter, as shown in Fig. 2.6. The raw coconut fibers show length varying from 15 to 35 cm and diameter from 50 to 300m. When they are immature and then become hardened and yellowed because a layer of lignin is deposited on their walls. Coconut fiber shows a good stiffness and is used in products such as floor mats, doormats, brushes, mattresses, coarse filling material, and upholstery