Optimisation of plastic injection moulding parameters for biopolymer composite using Taguchi L9 method and mould flow analysis

The production of bio-polymer composites through the injection moulding process often results in defects that can compromise product quality, especially when optimal parameters are not used for new materials. This paper addresses this issue by using a design of experiment and engineering software to simulate and optimise two cavities of a plastic injection mould for producing a biopolymer composite reinforced with banana fibre and high-density polyethylene (HDPE). The Taguchi L9 design of the experiment was employed to determine the optimal parameters, with each parameter simulated using the SolidWorks plastic injection to examine cavity filling, fibre degradation and sink marks. Three fibre particle sizes with different fibre aspect ratios were considered for simulation. The results showed that the temperature at the end of fill simulations was less than the degradation temperature of natural fibre. Moreover, the analysis using the Taguchi L9 alongside plastic flow simulation results, and the optimum parameters to produce a biopolymer composite were obtained. Specimens produced with these parameters exhibited good physical properties, as no sink marks or warpage were observed. The fibre aspect ratio plays an important role in the processing behaviour, mechanical properties, and final performance of biopolymer composites.