Wood fiber reinforced polypropylene composites: Compression and injection molding process

Wood fiber reinforced polypropylene composites containing different types of wood fiber (hard and softwood fiber) were prepared by an injection molding and a compression molding process. Influence of different processing systems and compatibilizer on the composite mechanical properties was investigated. The present study investigated the tensile, flexural, charpy impact, and impact properties of wood-fiber reinforced polypropylene composites as a function of processing system and compatibilizer. From the results, it is observed that injection molding process showed better tensile and flexural properties comparative with compression molding process, which is about 155% and 60% for tensile strength, and flexural strength, respectively. Charpy impact strength increased the maximum in compression molding for hard-wood fiber-PP (PP) composites, and it is about 70% at the wood-fiber content of 30%. Impact resistance in injection molding process shows better performance comparison to compression molding process and damping index decreased the most at about 60% in injection molding process for hard-wood fiber-PP composites at the wood-fiber content of 50%. Scanning electron microscopy of the composites also is investigated to better understand the interaction between wood fiber and polypropylene in both processing systems.