Abstract
The development of a formable or stampable advanced thermoplastic com posite sheet is described. This unique sheet structure is based on an excess filament length concept that enables excellent sheet drawability, making possible the fabrication of com plex shapes while maintaining high advanced composite properties. The analysis of two fiber structures are presented—namely, sine wave and straight/zig-zag fiber patterns. Data is presented to show the dependence of sheet property on fiber structure. Results of theo retical analyses for the prediction of sheet properties of known fiber structures are also presented. In general the straight/zig-zag fiber structure gives higher mechanical proper ties than the sine wave structure. Reasons for these property differences are suggested. Ex amples of parts formed to demonstrate the concept of fabricating complex shapes of high properties are shown. Even though the sheets before forming have lower strength, when the fibers straightened out upon forming, properties obtained were equivalent to those of straight continuous fiber composites.