When a glass bottle containing carbonated drinks breaks, for whatever reason, the compressed gas expands adiabatically to provide sufficient ballistic energy to propel fragments up to and beyond 10 metres from the location of failure. With PET bottles, the ballistic energy is directed at the cap and, if there is a transient mis-match between the cap and neck threads of the bottle, the cap separates explosively from the neck of the bottle; this is known by the industry as "missiling". The energy contained in the headspace volume gives rise to the many injuries sustained each year, particularly by children who tend to struggle to open the bottle in ignorance of the hazards. This study represents the outcome of several years of investigation by the author into ways of minimising and controlling, by packaging design, the pressure energy in the headspace of bottles and, thereby, eliminating or reducing foreseeable hazards of carbonated products.
