Partially compacted polypropylene glass fiber non-woven composite: Influence of processing, porosity and fiber length on mechanical properties and modeling

Non-woven materials feature unique properties that allow them to be used in different applications. In this study, polypropylene and glass fibers were commingled and pressed to obtain partially compacted composites. Fiber content, fiber length and processing parameters were modified to investigate their influence on the final properties of the composites. These were characterized by scanning electron microscopy (SEM), tensile and porosity measurements as well as fiber content and length distribution analysis. The stiffness of the composites increase linearly with increasing glass fiber content, from 1.6 GPa to 4.8 GPa. Longer fibers can be found in the composites with higher fiber contents. Applied pressure and number of stacked layers were found significant factors for the limitation of void content. Fiber-matrix interactions were improved with the addition of maleic anhydride grafted polypropylene, increasing the tensile properties in the low porosity range. A suitable model was found for the prediction of mechanical properties.