MODELING OF THE RELAXATION BEHAVIOR OF POLYPROPYLENE SHORT/FLAX FIBER INJECTED BIO COMPOSITES
In this paper, we present an extensive study on the relaxation behavior at different temperatures of parts injected in polypropylene/short flax fibers, as a function of the mold temperature and the fiber content. These made it possible to model and predict the long-term relaxation behavior of thermoplastic bio-composites. We proposed a generalized third order maxwell rheological model; involving three characteristic times describing the short, medium and long term relaxation times. A phenomenological approach was used by coupling the rheological model with the STT time-temperature superposition principle to predict the long-term relaxation behavior. A comparative study with the experimental results has been performed.
bio composites, polypropylene/short flax fibers, injection molding, relaxation, modeling