Low Cost Forming Influence On Reinforced Thermoplastic Mechanical Properties

This report describes a study of the influence of low-cost forming methods on the mechanical properties of reinforced thermoplastics. Two tasks comprise the main body of the study; one establishes a relationship between processing parameters (time/pressure/temp-variables) and selected material properties (modulus, flex strength, inter-laminar shear strength); the other determines the effects (measured by the change in material flexural properties) of simulated R & M solvent attack on painted and unpainted laminates. Two secondary tasks complete the study: a review of the available literature on industrial and government-sponsored reinforced thermoplastic materials, material properties, and fabrication methods. The other task required the manufacture of four, 16 in x 20 in, five ply Kevlar 49 style 285 fabric, polysulfane, laminated panels for AMMRC testing. Test data (with respect to processing parameters) indicates a decrease in flexural strength readings coming at the 450 F thermoforming temperature. Modulus values are highest in the 500 F - 550 F thermoforming temperature range. Interlaminar shear strength values also tend to decrease as thermoforming temperature increases. Regarding solvent attack, test data indicates generally higher flexural strength with polyphenylsulfone than with polysulfone sandwich beams. Conversely higher 'EI' values occurred in the polysulfone than in the polyphenylsulfone sandwich beams.