Abstract:Plants, such as flax, cotton, hemp, jute , sisal, kenaf, coir, pineapple , ramie, bamboo , banana, as well as wood, are a source of lignocellulosic fibers. Their availability, renewability, low density and price as well as satisfactory mechanical properties make them attractive reinforcing fibers in the manufacture of composites . The natural fiber containing composites are used in transportation (automobiles , railway coaches, aero-space), military applications, building and construction industries (ceiling paneling, partition boards), packaging, and consumer products.
INTRODUCTIONNatural fiber reinforced composites can be divided into groups: 1) conventional panel type composites where lignocellulosics serve as the main ingredient, e.g., particleboards, fiberboards, and insulation boards, with organic binding materials, including natural binders like lignin and tannin; 2) lignocellulosic-mineral composites which are based on inorganic binding materials; 3) natural fiber reinforced polymers, in which the lignocellulosics serve as reinforcing fillers within matrix materials such as thermoplastics , thermosetting plastics and rubbers; and 4) nonwoven textile type composites.The most important natural fiber composites are listed in Table 1 [1, 2]. The properties of composites depend on those of the individual components and on their interfacial compatibility .
CONVENTIONAL COMPOSITE BOARDSConventional composites fall into two main categories based on the physical configuration of the lignocellulosics: particleboards and fiberboards. Within each category are low, medium, and high density classifications. Also, both wet and dry processes are used for each category of composite. Conventional composites typically use a heat-curing adhesive to hold the lignocellulosic component together [3].Table1. Composites
ParticleboardsThe main lignocellulosic raw material used in the particle and fiberboard industries is wood, but in many countries other agriculturally based materials are successfully utilized. Annual plant waste such as flax and hemp shives, jute stalks, bagasse, reed stalks, cotton stalks, grass-like Miscantus, vetiver roots, rape straw, oil flax straw, small grain straw, peanut husks, rice husks, grapevine stalks and palm stalks are cheap and valuable raw materials for lignocellulosic board production.The production technology is similar to that for lignocellulosic board production from wood particles. All particleboards are currently made using the dry process, in which air is used to randomize and distribute the particles prior to pressing. The specifics of board production from annual plant waste are concerned with raw material preparation, including purification and sorting of the material [I, 2].One of the most important advantages of these boards is the ability to produce a wide spectrum of densities from 300 to 750 kg/m' (see Table 2). Annual plant waste boards are mainly used in the building and furniture making industries, and in transportation [4]. Particleboards, readily made from a vari...
