Numerical Simulation And Experimental Research On Shrinkage Of GF Reinforced PP

The shrinkage of plastic products is a very important parameter and need to be forecast during the design of injection molds, which affects the shape and size precision of the products. Therefore, the shrinkage of the glass fiber reinforced polypropylene specimens prepared by injection was investigated with the combination of the experiments and the simulation.The effect of injection molding parameters on the shrinkage of the glass fiber reinforced polypropylene samples was studied in this work, including mold temperature, nozzle temperature, injection speed, holding pressure, holding time and gate location. Then some measures were proposed to reduce the warpage and improve the quality of products. The experimental results showed that the shrinkage was increased with the increase of mold temperature and injection speed, with the decrease of nozzle temperature, holding pressure and holding time.Glass fiber reinforced polypropylene, nano-CaCO3/POE/PP ternary composites and glass fiber/ nano-CaCO3/POE/PP quadruple composites were also prepared to explore the effect of the content of glass fiber and nano-CaCO3. Based on the experimental data, the numerical models were built up according to Grey System Theory for the first time to predict the shrinkage of the three composites above. The calculated results were close to those from the experiments and their curves were very similar. Therefore the numerical models proposed in this work were proved to be able to analyze the shrinkage of composites.