The Impact Behavior of Thermoplastic Sheet Composites

Polypropylene sheet composites were produced by both the melt consoli dation and slurry deposition processes. The resulting composites had comparable flexural properties, based on the efficiency of the glass fiber reinforcement, but dissimilar impact strengths. The impact strength of the composites was found to be related to a number of factors, including the degree of adhesion between the polymer and reinforcing glass fibers, the concentration of glass fibers, and the length of the fibers. The impact properties of the melt impregnated composites were quite high. Melt impregnated polypropylene compos ites absorbed up to 257 J/cm during an instrumented falling dart impact test. The impact properties of the slurry formed composites were much less, only 62 J/cm.