Sisal-glass fiber hybrid biocomposite: Optimization of injection molding parameters using Taguchi method for reducing shrinkage

The current work presents an application of Taguchi method to optimize injection molding (IM) process parameters of sisal-glass fiber hybrid biocomposite. Six parameters that influence flow and cross-flow shrinkage such as injection pressure, melt temperature, mold temperature, holding pressure, cooling time and holding time were selected as variables and two hybrid biocomposites were used with different content of sisal (SF) and glass fiber (GF); SF20GF10 and SF10GF20. For the experimental design, L18 orthogonal array with a mixed-level design and signal-to-noise (S/N) of smaller-the-better was used. Optimal combination IM parameters were determined and the significant variables were identified using ANOVA. Optimized flow and cross-flow shrinkage values for SF20GF10 were 0.53% and 0.85% and the values for SF10GF20 were 0.47% and 0.88% respectively. Comparison was made with the shrinkage requirements of an automotive material specification suggesting that hybrid biocomposites with optimized IM parameters meet the dimensional requirements of automotive parts.