Polystyvert, a Canadian company that has developed innovative dissolution technology for recycling polystyrene, is collaborating with Coexpan, the Grupo Lantero division specialised in the manufacture of rigid plastic sheet and thermoformed products, to validate the use of its technology for FFS yoghurt packaging applications.
The initial trials conducted at Innotech, the innovation and development centre in Madrid, Spain, established in 2019 by Coexpan, a leading producer of Form Fill Seal (FFS) food packaging systems, and its sister company Emsur, have yielded positive results, in terms of both quality and processability.
As the solvent – an essential oil - in no way affects the polystyrene, Polystyvert’s recycled polystyrene retains the same properties as virgin polystyrene. Moreover, the processes are carried out at a low temperature, which keeps the molecular chain of polystyrene intact.
The technology was also found to successfully remove contaminants, including pigments and dyes, paper, cardboard, and other plastics, from the initial feedstock. The purification process takes place in a number of steps: first, the mixture of dissolved polystyrene and essential oil is poured through a simple mesh that catches contaminants like paper, tape, cardboard, other plastics and metals; second, the dissolved polystyrene is separated from the essential oil. This oil can be reused. This separation step also eliminates HBCD, a banned flame retardant still found in some types of polystyrene. Polystyvert has also developed a patented process to eliminate the fine particles and contaminants remaining in the solution, such as ink, or other types of additives. This not only sets the technology apart from a number of other technologies, but it also makes it possible to process a variety of difficult to recycle feedstocks.
The recycled PS was subsequently extruded and thermoformed produced during the trials was into yoghurt pots.
The pellets tested during the extrusion process were post-industrial rPS 50%, (ABA structure) and a monolayer structure with 100% post-industrial rPS. The sheets were tested on FFS industrial yoghurt packaging systems, and then analysed at the development centre laboratory.
The rPS successfully passed the challenge and migration tests. These results led to Polystyvert receiving a notice of certification for food contact in the USA from independent testing and quality assurance laboratory, Intertek.
Following these tests with post-industrial recycled material, the companies will commence trials with rPS derived from post-consumer waste in the coming weeks.
Founded in 2011, Montreal-based Polystyvert innovative, low-carbon-footprint polystyrene recycling process is based on a dissolution technology that is effective on all types of polystyrene. The result is a high purity recycled resource suitable for upcycled polystyrene products, and that opens the door to a larger rPS market than can be reached through mechanical recycling technologies alone.