Multilayered flexible plastic packaging has long been the bane of recyclers. Functional layers that are laminated together to create high-performance packaging solutions serve their purpose well during the lifetime of the product. The end of life is a different story: because separating these layers has, up until now, been a serious challenge, these highly-engineered laminates have, for the most part, simply been considered as being unrecyclable.
That’s all about to change, if Saperatec GmbH has anything to do with it. After years of working to develop an approach that separates plastics and other materials from one another, the Germany-based company has created technology that uses a combination of chemistry and mechanics, making it possible to delaminate thin-layer composite materials and enabling these to be recycled.
"Our world relies on advanced materials," CEO Thorsten Hornung said, speaking during an interview at K.
"Many of these important aspects of life rely on composite materials. And composite materials are, on the other side, hard to recycle. Because you have combination of plastics, paper, metals, glass and so on."
The company’s approach is based on a water-based fluid, developed after 10 years of research. No enzymes, no solvents.
“In 2016 or thereabouts, the management decided to focus on laminated flexible packaging and the fluid that was tested and invented and improved over the past years was then dedicated to these applications,” said Lars-Oliver Stock, COO at Saperatec.
“It’s based on mechanical recycling, but we have a delamination step in between. Our focus right now is flexible packaging with an aluminium barrier layer, used generally for applications such as coffee pouches and dog foods.”
He added that the feedstock mainly comes from the PolyAl waste from beverage cartons. “Nowadays the PolyAl goes into incineration most of the time or into concrete applications. Another source is postindustrial film foil misprints, roll ends. There's a lot of waste during production which is very clean pure material.”
He continued, adding that the idea for the technology came from the university, which led to the founding of the company. We started at lab scale and worked steadily further, first moving to a 3-litre scale where we could process maybe 100 grams at a single time, and ultimately reaching pilot plant scale, where we have a cubic meter vessel to which we can add maybe 50 to 100 kilos of material,” explained Stock.
How does it work?
The process is a hot wash one, said Hornung. Perhaps the best way to visualise this is to compare it to doing the laundry. Except the washing machine is actually a giant vessel - think something like a fermentation tank found at a craft brewery - that heats and stirs laminated packaging that's been shredded to just a few centimetres in size.
"Then we add our specially formulated separation liquid," he said.
Chemistry allows the liquid to get in between layers and the heat and agitation helps complete the process, resulting in plastics separating from other constituents.
Saperatec uses different chemical mixtures for different applications based on what is being processed.
"Packaging is our focus right now. That's where we’ve commercialised the technology. But we also have working solutions plastic compositions like car safety glasses, like electronic device displays," he said.
Once materials are separated, they are washed, screened, sorted and dried. The separation liquid is reconditioned and can be reused more than 30 times, the company said. And the chemistry, which Saperatec does not reveal, is so mild that spent liquid can be discharged to municipal wastewater treatment plants, the CEO said.
The separated plastic - such as polyethylene - is then processed into a regranulate using established technology, from which plastic foils can be produced again. The separated aluminium foil is supplied to aluminium producers for reuse.
New plant
The company is now constructing its own first commercial-scale processing plant at an existing industrial site in Dessau-Roßlau in Saxony-Anhalt, Germany. Spanning some 5000 m2, it will initially process 18,000 metric tons of material each year. Eventually, that number is expected to reach 30,000 tonnes.
“We are currently moving in the equipment ,” said Stock. “Commissioning will take place during the summer of next year.”
The project is being funded by the federal State of Saxony-Anhalt and the European Union as part of the Horizon 2020 research funding programme.
This first plant will run on a continuous basis by relying on the output of 10 separate delamination tanks, the CEO explained. While delamination will take place as a batch process, the facility actually will operate on a continuous basis in the steps leading up to and after delamination by moving from one tank to the next.
Saperatec’s ambitions do not stop at this first plant.
"We are set to grow this technology beyond this first plant,” said Horning. “We will start looking for further projects next year, essentially discussions about that have already started. We plan to bring this technology not only to the European Union but also to other markets," he said.
The company’s product can also be used by companies who need to comply with upcoming European legislation requiring products to contain at least 35% recycled material.
“That's what we are demonstrating here: derived from film, it can go back into film, in a closed loop. Up to 50% is possible,” he said, pointing to the pouch displayed on the stand made from 35% recyclate derived from beverage cartons.
The response at K has been very positive, he added. “Three years ago we were at K as well and there we demonstrated the concept of what we would like to do. And now, this time, we've done what we promised to do: it's no longer a concept, but we are putting it into reality. We're building a plant.”