Manufacturing and Characterization of Polypropylene-Paper Composites for Automotive Applications

The automotive industry is under significant pressure to curb greenhouse gas emissions from their products as the negative impacts on the environment are increasingly apparent. As such, there is significant interest within the industry to develop low-carbon footprint materials. Natural fiber composites are therefore appealing due to both their decreased carbon footprint, as well as their relatively low cost, low density, and beneficial acoustic properties. This research specifically focuses on the use of paper fibers as composite reinforcements. Paper offers additional benefits over other natural fiber types in that it is globally available, does not compete with food resources, and has well-established quality control techniques. The goal of this work was to study the manufacturing of polypropylene (PP)-paper fiber composites using a hybrid wet-lay/compression molding processing. The processing parameters studied included molding temperature, molding duration, and molding pressure. Paper composites were characterized for properties including flexural strength, impact strength, and water uptake rate. An optimal set of processing parameters was identified in which cycle time and energy inputs (e.g. temperature and pressure) were minimized while retaining desired material properties.