Mechanical recycling of flexible plastic films

Plastics are light-weighted and inert materials and they have become essential in our daily life, especially for the usage in packaging section. With the large production and short lifecycle time, the waste management of plastic packaging materials is important for sustainable development. The recycling of the plastic films from mixed municipal solid waste is of great interests to investigate. In this study, five different plastic films samples were engaged and three of them were recovered from mixed municipal solid waste and the rest two were source separated samples. All of these five samples were recovered through a series of processes consisting of shredding, screening, washing, density separation and drying. The configurations of the processes were varied in order to investigate the difference between screening or non-screening and hot or cold water washing. Energy consumption, recovery and yield of each trial were measured and analysed. Results showed the recovery and energy consumption of samples from mixed municipal materials are in the same level of source separated samples. Furthermore, one of the samples from mixed municipal solid waste was also recycled in a centrifuge-sorting featured process. The washing and drying performances of centrifuge sorter were evaluated; the recovery and energy consumption were derived to compare with the first process. However, the result showed that the centrifuge sorter did simplified the recycling processes by merging screening, washing, density separation into one centrifuge sorting step with good recovery, but the energy consumption was much higher than the first mechanical recycling method because of the low throughput