ss4.jpgThe concept of 'green' economy is supported by energy efficiency, renewable feed stocks in polymer products, encouraging industrial processes that reduce carbon emissions and producing recyclable materials. The popularity of natural fibres is undeniably based on the fact that natural fibre is not only good for skin, but it is also good for the environment. As a matter of fact, growing one tonne of jute fibre requires less than 10 percent of the energy used for the production of polypropylene, a plastic polymer.

Earlier, Sisal was widely used in ropes, general cordage and twines, but product varieties gradually increased, as companies started using sisal to manufacture paper, buffing cloth, dartboards, handicrafts, Macram, carpets, geotextiles, wire rope cores and mattresses. Other sisal-inclusive products now range from steel cable yarn to twisted thread, and general yarn to knitted art crafts.

The use of sisal in non-woven textile is also of prime significance, as sisal is an environmentally friendly strengthening agent to replace asbestos and fibre glass in composite materials. This has led to increased employment of sisal fibre in the automobile industry. The use of sisal fibre depends on its grade.

Sisal is broadly categorized under three grades, which are lower, medium and high grades. Manufacturers in the paper industry use lower-grade fibre due to significant portion of hemicelluloses and cellulose found in that variety. Handled by the cordage industry, medium-grade fibre mostly is diverted to the production of binder twine, ropes and baler. These products are primarily used for agricultural, marine and general industrial purposes. The third quality, a high-grade variety of sisal, is put in the works by the carpet industry to manufacture yarns. In case of carpets, sisal is used by itself or in blends with wool and acrylic for a softer hand.

Sisal fibre is made from the process of decortications. Under this process, leaves of sisal plant are compressed and trampled by a revolving wheel set. The set contains blunt knives, so that only fibres remain. The remaining parts of the leaf are washed away by water. The decorticated fibres are also cleaned by water before drying in the natural heat or by the artificial process of hot air. The grade of fibre is decided on the basis of the moisture content so appropriate drying is imperative. Artificial drying is preferred for better grades instead of natural sun drying. After drying, the fibres are untangled via machine and categorised into grades. Another process used to separate fibre from the leaves is retting followed by scrapping. Under the retting process, a combination of bacteria action and moisture is taken into effect for rotting of plants. The process gets rid of cellular tissues and gummy substances around bast-fibre bundles, helping the fibre to separate from the stem.