ABSTRACT
This chapter introduces the commercially most relevant constituents and describes available forms and types, applications, and characteristics. The matrix of a composite has several functions: it is a binder that holds the reinforcement in place, it transfers external loads to the reinforcement, and it protects the reinforcement from adverse environmental effects. The reinforcement is the constituent that primarily carries the structural loads to which a composite is subjected. The reinforcement therefore to a significant degree determines stiffness and strength of the composite as well as several other properties. Composite reinforcement may be in form of fibers, particles, or whiskers. Drape and flexibility is typically poor for solvent-impregnated materials and melt-impregnated materials, whereas tack is achievable with thermosets. Not surprisingly, high quality of impregnation goes hand in hand with high cost in solvent-impregnated materials and melt-impregnated materials.
