Fundamentals of Composites Manufacturing: Materials, Methods, and ApplicationsThis chapter examines the following concepts: general fiber characteristics, glass fibers, carbon/graphite fibers, aramid and other synthetic organicmfibers, boron, silicon carbide, and other specialty fibers, natural fibers, and fiber-matrix interactions. Reinforcements for composites can be fibers, whiskers, and/or particles. Each has its own unique applications, although fibers are the most common and have the greatest influence on the mechanical properties of the finished part. In fact, the influence of fibers, especially long fibers, is so dramatic that composite materials containing long fibers might be considered a new class of solid materials beyond the traditional materials — ceramics, metals, and polymers. The most common organic fibers used for reinforcements are the aramids. When fiber reinforcements are put into composites, the overall properties are decreased because the fiber does not occupy all the volume. Thus the composite properties are a combination of the fiber and the matrix.