Properties and Formability of an Aligned Discontinuous Fiber Thermoplastic Composite Sheet

A thermoformable thermoplastic composite sheet product is described. The sheet consists of aligned discontinuous reinforcing fibers in a thermoplastic resin. It is drawable to 50 % or more axial draw ratio and has mechanical properties close to those of straight continuous fiber composite sheets. Development and preservation of fiber alignment enables the achievement of high fiber volume fraction (FVF) and mechanical properties. In general, tensile modulus and strength are 90% or better of continous fiber composites at the same FVF. Fatigue and creep properties are also comparable. This paper details the mechanical and formability characteristics of the sheets and presents various applications that show the processing advantages of this advanced composite sheet concept over straight continuous fiber or woven fabric sheets.