An Energy Saving Approach in the Manufacture of Carbonated Soft Drink Bottles

Abstract

The use of plastics for packaging has been increasing steadily over the years. Polyethylene terephthalate (PET) dominates the carbonated soft drinks (CSDs) market as the main material used in this application due to its toughness, clarity and superior barrier properties. Currently, the CSD bottles constitute 40% of the global PET consumption. PET bottles demonstrate favourable life cycle inventories compared to alternative packaging materials such as aluminium and glass. Manufacturing of the bottles starts with the production of PET resin from petrochemicals. The PET resin is then melted and injected into a preform mould which has the shape of a test tube with a threaded neck. Subsequently, the preform is heated to a certain temperature, and stretched and blown simultaneously to take up the shape of the bottle mould. Each of these steps requires energy. In this study, we will focus on the environmental footprint of CSD bottles and demonstrate that light-weighting of CSD bottles through a new bottle/preform design brings about energy reduction and greenhouse gas savings.