From the 1970’s onward, petroleum-based fibers replaced natural fiber so that, worldwide, the cropping of natural fibers entered into steep decline, causing economic stagnation in the producer regions. In addition to the competition with synthetic fibers, innovation in transport facilities also contributed to the decline of natural fibers, particularly the advent of commodity bulk handling facilities in long distance trade, which eliminated the use of food-grade sacks altogether.
Jute has always been the most important natural fiber but it too suffered long decline. In 1990, 2. 1 million hectares were planted in jute, which fell to 1. 6 million in 2000 and is projected to slump to 1. 2 million hectares by 2010, a retraction of about 3% a year. During the same period, production also fell from 3. 3 million tons to 2. 6 million tons and is projected to diminish to 2. 3 million tons by 2010. During this period jute consumed in the developed countries fell by 40% and that consumed in developing countries by 10%. 1) During the past two decades, there has been a renewed interest in development of natural fiber plastic composites for the consumer industry. Two of the most prominent factors that are fueling this resurgence originate from the environmental impact of using these composites and the technological advances that address the disadvantages of fiber composite production and usage. Natural fibers have assumed considerable environmental importance in function of being produced with renewable energy sources, consuming less energy to produce and being biodegradable and recyclable. 2) In the traditional furniture, shoe, and textile manufacturing sectors, natural fibers are increasingly being used as a substitute for fiber glass. Natural fibers have several advantages as compared to conventional plastic, such as being from 10% to 30% cheaper; having lower density, superior thermal properties and low embodied energy; involving lower tool wear in the moulding process; producing better acoustic proprieties and reducing irritation to the skin and respiratory system (3).
Ironically, a number of the perceived advantages of natural fibers in composite polymers were cited in the past as disadvantages which led to the substitution of natural fiber by synthetics. Natural fibers were said to be inferior because they were not water resistant, were porous and breathable, were biodegradable and were not adaptable to automatic sack filling. The water resistance problem has been overcome by surface modification of fibers, creating hydrophobic coatings that allow for a moisture barrier as well as better adhesion with the matrix resin.
Breathability is now seen to be an advantage in reducing heat and impregnating odors, particularly in textiles. Similarly, bio-degradability is highly desirable today as well as the characteristic of being recyclable. All of these characteristics now perceived to be desirable have stimulated a good deal of research into finding other industrial applications which could cause fiber production to expand even further. (4) 1. Food and Agriculture Organization (FAO). 2003. Medium-Term Prospects for Agricultural Commodities: Projections to the Year 2010.
Rome. 2. Jan, E. G. 2009. Environmental Benefits of Natural Fibre Production and Use. In Discover Natural Fibres: Proceedings of the Symposium on Natural Fibres, p. 3- 17. Rome: FAO. 3. Suddell, B. C. 2009. Industrial Fibres: Recent and Current Developments. Discover Natural Fibres: Proceedings of the Symposium on Natural Fibres, p. 71-82. Rome: FAO. 4. Bicalho, A. M. 2009. Agricultural-Industrial Integration and New Applications of Natural Fibers: Jute Floodplain Cropping in the Amazon Reborn. Brazil