Applications Primary and Secondary Functions

- Kenaf Eco Fibers Italia S.p.A., Guastalla, Italy Holstein Flachs GmbH, Mielsdorf, Germany Procotex SA Corporation, Belgium SANECO, France 

The environmental benefits of wood and other natural fibers have been an important influence on their use, particularly in Europe. Natural fibers are derived from a renewable resource, do not have a large energy requirement to process, and are biodegradable [21]. 

Natural fibers are hydrophilic and do not tend to be easily wetted or bond well with many matrix materials, particularly the commodity thermoplastics. Coupling agents, such as maleated polyolefins, silanes, and isocyanates, are often necessary for adequate performance. A wide variety of coupling agents, fiber surface modifications, and treatments has been investigated for use in natural fiber plastic composites and are reviewed elsewhere [22]. 

Recently, new compounding methods have been investigated to produce long, natural fiber-reinforced thermoplastic pellets and improve composite mechanical properties [31, 32]. For example, pellets have been formed by melt impregnation of continuous natural fiber yarns by pultrusion followed by cooling and chopping. Another method involves commingling of continuous forms of natural and synthetic fibers that are then heated, consolidated, and chopped. 

Many reasons such as lack of familiarity and the current, limited availability have so far prevented large-scale penetration of these materials into broader injection-molded markets. However, double-digit growth is still expected as large companies enter the market and technological advances are made [32]. 

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