A newly-developed technology for the production of food-grade recycled PET pellets combines Austrian machinery maker Erema’s Vacurema bottle-to-bottle process with vacuum-supported solid state polycondensation (SSP) from Polymetrix.
All thermal process steps in the Vacunite technology take place in a nitrogen atmosphere, which results in a solution to what Erema calls the challenges that PET recycling will have to face in the future. A first customer in Europe has already invested in a Vacunite recycling plant prior to the official launch.
Speaking at the technology’s launch, Christoph Wöss (pictured right), Erema’s business development manager for the bottle sector, summed up these challenges.
“The growing commitment in society to handling plastics in a responsible way means that both political requirements and voluntary pledges of major beverage brands call for a significant increase in the amount of recyclate in end products,” said Wöss.
“To fulfil these requirements, even more material in general and with varying quality due to different collection systems has to be recycled while, at the same time, the big brands are becoming even stricter with their requirements regarding the recyclates produced.
“Our new development brings together the best of what is technically possible. All thermal process stages take place in nitrogen atmosphere, largely eliminating flake and pellet discoloration and reliably removing additives, which could lead to undesired reactions in the melt. Another benefit of Vacunite – the vacuum support cleans the nitrogen – means it can be returned to the previous processing stage and nitrogen consumption is reduced as a result. Any remaining dust particles are removed from the pellets before filling to avoid preform contamination.
“Using vacuum support and nitrogen atmosphere creates rPET recyclates that far exceed all existing food contact requirements, even those of the major beverage brands.”
The energy consumption of Vacunite for the entire production process from the flake to the final pellets is said to be 0.35 kWh per kg.
Manfred Hackl, chief executive of Erema, added: “With Vacunite we offer our bottle-to-bottle customers a new technology in addition to the existing portfolio, which sets new standards at all levels from technical performance to rPET quality.”