Recycling of wasted multi-layer films containing an aluminum layer

Multi-layer films can not be easily separated into their components because several thin films of different plastics are laminated together. For real "Recycling" of multi-layer films, they must be separated into their components. Generally in a scaled-up recycling process, separation a plastic from the other plastics is more difficult than from impurities, therefore, separation of each plastic is very important to achieve the real "Recycling". There have been many methods using density and spectroscopic difference for the separation of mixed plastics. All the present methods except selective dissolution process can not be applied to recycling of the multi-layer films. Multi-layer films usually contain low-density polyethylene(LDPE), polypropylene(PP), polyester(PET), and aluminum layers. Since multi-layer films usually contain an aluminum layer, the recycling process becomes more difficult. Aluminum can be selectively dissolved in alkaline aqueous solution, and LDPE and PP can be selectively dissolved in xylene at around 75 degrees C and 118 degrees C, respectively. In this study, methods to separate each component plastic from multilayer film waste, one at a time, have been characterized in terms of yields, purity and speed.