Optimization Of Injection Moulding Process Parameters For Recycled High Density Polyethylene (RHDPE) Using The Taguchi Method
In this work, recycled High Density Polyethylene (rHDPE) from the industry disposal is investigated as potential recycled plastic to substitute its virgin source for the injection moulding process. In particular, the study aims to determine the optimum process parameters for the rHDPE in the application of injection moulding process. Taguchi method is adopted to optimize the process parameter combination from the four controllable process parameters, namely the melting temperature, packing pressure, packing time and injection pressure. The effects of the process parameters are evaluated and benchmarked against the established mechanical properties and dimensional stability of the moulded plastic tray from virgin source. The result of the study reveals that the qualities of the moulded rHDPE plastic tray are good and optimized under the process combination of the melting temperature of 513.15 K, packing pressure of 70%, packing time of 30 s and injection pressure of 15 MPa for the shrinkage; meanwhile the combination of melting temperature of 518.15 K, packing pressure of 85%, packing time of 30 s and injection pressure of 15 MPa for the tensile strength and lastly, the combination of melting temperature of 518.15 K, packing pressure of 80%, packing time of 10 s and injection pressure of 14 MPa for the flexural strength. The feasibility to injection moulded rHDPE and optimize the process parameters shows huge potential of using rHDPE as sustainable alternative to virgin HDPE as the raw material for injection moulding process.
Index Terms- Recycled High Density Polyethylene, Taguchi Method, Injection moulding, Mechanical Properties, Shrinkage, Green Manufacturing