Sesotec sorting systems to keep material flowing at New Zealand's first PET recycling plant

Sesotec has supplied a multi-sensor sorting line at New Zealand's first PET recycling plant operated by Flight Plastics Ltd. According to the Germany-based technology provider, the Sesotec sorting systems there will secure output quality as well as a continuous supply of PET flakes to the Flight's production line.

Approximately 20,000 tons of virgin PET is imported to New Zealand annually. The government's Waste Minimization Fund there supports projects to reduce any resulting environmental harm, and a government grant has enabled Flight Group Ltd. to open New Zealand's first PET recycling plant in Wellington. The company has spent NZ$ 12 million (US$ 8.8 million) on a full upgrade at its facility, including a wash plant for PET bottles.

Flight Group was established in 1907 and initially made leather luggage. It is still privately held by members of the original Osborne family owners. Flight Group moved into plastic production in the 1970s, and has PET product manufacturing plants in Adelaide, Australia, and Romsey, England.

Keith Smith, CEO of Flight Plastics Ltd in Wellington said the upgraded wash plant and other work at the facility enables Flight Plastics to produce thermoformed packaging from recycled PET bottles. The company installed extrusion equipment to use recycled PET flakes starting in 2014, using imported flake to prove the process and establish a customer base.

According to Smith, they had very encouraging results, so the next step was to install their own wash plant. Flight Plastic now has the capacity to recycle 6,000 metric tons of PET a year. It gets feedstock from curbside programs around the nation, which collect about 8,000 tons annually.

Sorting bottles and flakes 
As a part of the investment in their wash plant, Flight Plastics' new multi-sensor sorting line includes two Sesotec bottle sorters and a flake sorter. The system is designed to secure output quality and a continuous supply of PET flakes to the production line. After the upstream process steps such as bale breaking, the bottles are fed to Sesotec‘s VARISORT MN multi-sensor sorting system. This system was installed for the separation of PET bottles from other polymers, using a near infrared sensor (N) as well as metals sensor (C). 

Flight Plastics also decided to install a further VARISORT, model CN. This second VARISORT is equipped with colour sensors (C) and near infrared sensor (N) for material identification and sorts as well as cleans the PET bottles into a transparent clear and a coloured fraction. Those sorted bottles are fed into a cutting mill where they are cut to the desired flake size and passed through a washing and drying process. 

In the next step Sesotec‘s FLAKE PURIFIER multi-sensor-sorting-system is used for a final cleaning of the PET flakes. Here the remaining off-colours, wrong polymers and small sized metal pieces will be removed. 

According to Sesotec, this multi-sensor configuration equipped with a high resolution out-blast system allows for the highest possible sorting efficiency combined with lowest possible material loss rates. Depending on the application the three sensors can be used individually or in combination.

Sesotec is headquartered in Germany, but has a global footprint, which includes a total of seven subsidiaries in Singapore, China, the US, Italy, India, Canada and Thailand, as well as more than 60 partners in key markets around the world.