Analysis of process parameters affecting energy consumption in plastic injection moulding

Abstract

Sustainable manufacturing has become essential amongst industries of all types due to the diminishing non-renewable sources and an ever-increasing demand for environmentally friendly products. Injection moulding is one of the most widely used processes for the production of plastic products and is a large consumer of energy. Energy efficiency has become a serious concern due to the rising energy costs and the associated environmental impacts. IEA (2007) reports that one third of the global energy consumption and 36 percent of ଶ emissions are attributed to the manufacturing sector. The aim of this study was to optimize the injection moulding process in order to reduce energy consumption whilst also ensuring no loss in part quality. This was achieved by investigating the impacts of cooling time, screw rotational speed, mould temperature and nozzle temperature. It was found that the cooling time and the nozzle temperature had the greatest impact on energy consumption. The mass and length of the part were not affected by any of the parameters within the selected processing windows, while the surface roughness was slightly influenced by the mould temperature range. Results indicated a possibility of using lower cycle times and lower nozzle temperatures to decrease energy consumption without having adverse impact on part quality. When comparing the energy consumption while using process parameters set at their minimum values compared to midpoint values, savings of 14 percent were achieved.