Multi-objective optimisation of plastic injection moulding process using mould flow analysis and response surface methodology

Concurrently maintaining a stable part weight and high production rate has remained a challenge in injection moulding. As a statistical tool, response surface methodology (RSM) was exploited to examine effects of process parameters on part weight and production rate. The objective was to optimise process parameters in order to obtain weight stability at high rates of production. The study took advantage of validated numerical simulations using MoldFlow to generate input data required in statistical analysis. Analysis of variance revealed that packing time has a consequential impact on both responses, where an increase in packing time resulted in high part stability, but a low production rate. Real-scale test using optimal parameters producing the best trade-off between part weight and production rate was performed to validate efficiency of the optimisation procedure. The part weight and production rate predicted by RSM were in good accordance with experimental observations, with relative errors of less than 2.5%.