Siegwerk, one of the leading global providers of printing inks and coatings for packaging applications and labels, has partnered with German startup Wildplastic and the Hamburg University of Technology (TU-Hamburg) aiming to increase the recyclability of plastic waste. One way to achieve this is by successfully deinking the collected waste before entering the recycling extrusion process. The partners conducted initial trials at the end of 2022, with very successful results.
Of the billions of tons of plastic that have been produced worldwide, only about 9% has been recycled, and about 12% ends up in landfills. The rest can end up leaking into the environment, polluting oceans and rivers and breaking down into microplastics that are hazardous to human health. There is a clear and urgent need to improve recycling processes and to ensure that more packaging enters the recycling stream. Deinking packaging prior to regranulation helps to prevent the packaging inks from contaminating the materials to be recycled, and ensures that the packaging stays in the recycling stream.
In cooperation with communities of collectors, Wildplastic works globally to collect ‘wild’ plastic from beaches, landfills and illegal dumpsites. In 2019, it started selling the first trash bag that is 100% made of recycled plastic. Currently, its focus is on sourcing Low Density Polyethylene (LDPE) such as bubble wrap or certain food packaging. LDPE cannot yet be widely recycled, so the market collection incentive for it is still limited.
Wildplastic wants to change this by creating a demand for this material and showcasing the potential of post-consumer LDPE recycling. After collection, the plastic is transported to a recycling partner who washes, melts and processes it into granules. These recyclate granules are then sent to a production partner and used as a substitute for virgin LDPE material. This material is then used to create trash bags and mail bags. A broader scope of applications may be possible if the materials could be successfully deinked first.
“We started to conduct research on deinking of post-consumer plastic waste with Wildplastic about one year ago.” said Jinyang Guo from the Institute of Circular Resource Engineering and Management (CREM) at TU- Hamburg. “As a technical university, it is important to carry out meaningful research relevant to the real-world problem. From our project, we have learned that a successful circular economy only works by motivating all the stakeholders involved. Siegwerk as the producer of printing ink, can play an important role in this context since it brings the producer’s perspective to solve the problem in the beginning.”
Siegwerk is supporting Wildplastic in this initiative by providing the deinking chemistry and knowledge to enable the creation of clean recyclates. In order for successful deinking to occur, a precise combination of the right ink chemistry, the right deinking detergent and the right process needs to be applied. Inks on packaging can often be a hinderance to recycling, as the inks degrade during the recycling process and can contaminate the recyclates, leading to unpleasant odours or unsightly colours. Even if the inks are not totally removed, the opportunities for recycling are increased exponentially.
Siegwerk and Wildplastic are collaborating to showcase the potential of post-consumer LDPE recycling