Innovative PET recycling method

More than 117 representatives of the plastics industry from 24 countries met for an open day on November 8 at the Next Generation Recycling Machines (NGR) facility. In cooperation with KUHNE GmbH, an innovative recycling process for polyethylene terephthalate (PET) was demonstrated to the audience and this new Liquid State Polycondensation (LSP) recycling method opens up completely new possibilities for the plastics industry.

 

PET is a thermoplastic that is widely used in beverage bottles and numerous other food contact applications, as well as in the manufacture of textiles. Previous methods of recycling PET back to near-virgin quality have shown limitations. Achieving food grade standards, decontamination and rebuilding of the molecular chain structure takes place in the liquid phase of the PET in the LSP process. This principle allows recyclers more flexibility with regard to the input materials. Different forms of PET waste can be mixed and recycled. This means not only bottle flake, but also scrap fiber, sheet, thermoform waste, strapping, and other lower value scrap streams can be recycled to much higher IV and higher value recycled products. In addition, the NGR process at the outlet provides controlled mechanical properties of the recycled PET. 

 

 

Furthermore, LSP can be used to process co-polymer forms of PET (PET-G) and polyolefin contents (e.g. PE) without any problems. In addition, it had been demonstrated that PET/PET-G as well as PET/PE compounds can be easily and safely processed using Liquid State Polycondensation without any limitations. Such process has not been made possible with existing conventional recycling processes.

 

After the melt has passed the LSP reactor, it can either be granulated or – like at the demonstration in Feldkirchen – processed to FDA approved film with outstanding optical and mechanical properties by implementing devices such as a sheet die, a roll stack, cutting devices or a winder. These films are mainly used for thermoforming applications. With the new LSP concept, the customers are given energy-efficient alternative solution in order to produce highly-sophisticated packaging films out of PET with originally bad physical properties.