Continuous natural fiber-reinforced

Heirera-Franco PJ, Valadez-Gonzalez A (2004) Mechanical properties of continuous natural fiber-reinforced polymer composites. Compos A 35 339-345... 

Pellet Manufacturing Technology of the Continuous Natural Fiber-Reinforced Thermoplastic Resin Composite Material... 

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. 

For the manufacturing of injection-moldable natural fiber/PP-compounds, the band of the fiber is impregnated by the PP-melt in a continuously running extruder line. The natural fiber reinforced compound is granulated at the extruder exit. Melt compoimding of short-cut fibers has not proved viable because of metering problems with the natural fibers. 

The potential use of natural fiber composites is diseussed in this chapter. One of the most important reasons for the increasing trend in the production of natural fiber eomposites is due to easy and economical disposal of the wastes. There is a lot of scope in the future for researchers and industrialists in the field of natural fiber reinforced composites. A significant amount of research work has been carried out in the field of natural fiber composites and yet more investigations have to be made with polymer composites. To wider the applications of these fibers in solving environmental problems, more studies have to be continued in the future. 

The properties of thermoplastic composites containing fibers as fillers are dependent on a number of parameters, which include the properties of the matrix material, the size and aspect ratio of the fibers, dispersion of the fibers and the interface. In development of these composites, two important issues need to be addressed, namely, the incompatibility between the natural fibers and polymer matrix, and the tendency of the fibers to form aggregates [67]. Additionally, the composites exhibit poor dimensional stability due to moisture absorption. The orientation of the fibers is also important. In short-fiber reinforced composites, the orientation of the fibers is usually random and therefore the properties of such composites are not as superior as those containing continuous fibers. Optimization of processing conditions and use of coupling agents/compatibilizers and treatment of fibers can enhance the properties of these composites. 

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