How is coir fiber made?
The steps involved in the manufacturing of coir fabric are as follows:
• Harvesting and Husking:
This process involves extracting ripened or mature coconuts from the trees. However, an unripe coconut can also be seasoned by placing them in a single layer on the ground for a month or so and keeping them dry. Once the coconut has been obtained the next step is to remove the husk for which the coconut is placed on the steel-tipped spike which splits the husk. This may be carried out manually or using a husking machine.
Retting process is carried out to soften the coconut husk by steeping them in water as a result the husk pulp gets decomposed by the action of microbes and the coir fibers are separated while the residue obtained is called coir pith. Retting is of various types. Let’s discuss each one of them precisely:
• Freshwater Retting: The ripe husk is soaked in the freshwater for about six months either in tanks or containers filled with water, concealed in the pits build under the ground along the riverbanks, or immersed in the river using nets that are weighted to keep the husk submerged.
• Saltwater Retting: This type of retting is carried for about 10 months however certain bacteria can be introduced in water in order to reduce the time duration. Unripe husks are soaked in seawater or in a container filled with saltwater. This process is carried out by either constructing pits underground by the side of the riverbank near the ocean
• Mechanical Method: The whole process of retting is quite tedious and takes a lot of time and hence the mechanical method has been developed which reduces the retting time. Ripe husks are processed in crushing machines after being soaked in water for about seven to ten days. The crushed husks are then again immersed in water for one to two days. Immature husks can be dry milled without any retting and are used for making mattress fibers.
• Pounding, Cleaning and Drying:
The retted pulp is then pounded on wooden mallets to extract the fibers from the pith. Machines have also been developed that separate the fibers. The fibers so extracted are then washed and combed and further dried on the ground. The fibers spread for drying are beaten and tossed up a few times to get rid of any impurities or remaining pith that might still be present.
Lastly, the fibers so obtained are spun to make yarns and then woven to make textile material such as mattress, floor mats, sofas, settees etc.