Plastic Recycling : STADLER completes reconstruction of the Sortierkontor Nord lightweight packaging plant in Bremen

STADLER Anlagenbau GmbH, a German company specialising in the planning, production and assembly of turnkey sorting plants, carried out the reconstruction of Sortierkontor Nord's (SKN) lightweight packaging facility in Bremen, Germany. Following severe damage to parts of the plant in two fire incidents in 2022, SKN — operated as a joint venture between Nehlsen AG and PreZero Recycling Deutschland GmbH — tasked STADLER with redesigning and rebuilding the affected sections, focusing on ensuring the facility is fit for the future in terms of safety, automation and operational reliability.

Originally designed and commissioned by STADLER in 2021, the facility is one of Europe’s most modern sorting plants for lightweight packaging. It processes around 120,000 tonnes of material per year from dual collection systems in Bremen and the surrounding federal states. With the rebuilt plant commissioned in early 2025, SKN has restored its original throughput and set a new standard in terms of fire protection, sorting stability, and preparation for automated battery extraction — an increasingly critical challenge for the waste and recycling industry.

Unlike a conventional plant build, around one-third of the machinery area was destroyed during the reconstruction process. Despite extensive preservation measures, further damage to standing equipment occurred during the complex insurance settlement process. STADLER integrated state-of-the-art sorting technology into the existing structure while meeting significantly higher safety requirements.

'Fire incidents in light packaging plants tend to cause immense damage because hazardous components, such as lithium-ion batteries, are often concealed in the material stream,' explained Tom Schmitt, STADLER's Sales Manager. 'In redesigning the Bremen facility, our priority was to ensure stable sorting performance while significantly increasing fire safety. This involved architectural changes, new system layouts and integrating technologies inspired by our latest projects.”

A key change to the new design was to relocate the initial classification steps – air separation, magnetic separation and 2D Flex sorting – to a hall that is structurally separate from the main machinery area. This spatial redesign increases fire protection by isolating these critical early stages of the process, thereby reducing the plant’s overall vulnerability to fire-related incidents. The addition of a second 100-cubic-metre fire-extinguishing water tank, together with modern fire-protection systems including sprinklers and integrated fire-suppression lines on equipment such as trommel screens, further enhances fire safety.

The rebuilt sections of the plant now feature an optimized flow that reduces material bottlenecks and inefficiencies of the original setup. Three trommel screens, previously positioned in a single area and connected by long conveyor belts, are now arranged opposite each other for smoother, more accessible operation. Films – one of the highest-volume fractions – are now sorted fully automatically, with the option of integrating a third sorting stage in the future. SKN now produces transparent LDPE and mixed-film fractions with improved consistency and reduced manual handling.

The plant continues to deliver twelve high-purity mono-material fractions, including PP, PET, PE, PS, mixed polyolefins, paper-cardboard-carton, aluminum and additional composite materials. At the same time, the redesign enables the future integration of automated battery extraction technology similar to the system installed at PreZero’s Sollenau facility, which can detect and remove batteries.

“Restoring and securing the sorting capacity was our first priority,” said Benjamin Kreie, Managing Director of Sortierkontor Nord GmbH & Co.KG. “But together with STADLER, we went far beyond reconstruction. The modified sorting technology, the creation of more monitored fire sections, and the possibility to integrate battery extraction all raise the plant to a new level – safer, more robust, and better suited for current and future waste streams.”

“Achieving the highest possible level of fire protection – technically and organizationally – was crucial for us,” added Andreas Thiel, Managing Director of Sortierkontor Nord GmbH & Co. KG and Branch Manager at PreZero Recycling Deutschland GmbH. “The new plant structure, together with state-of-the-art sorting systems, allows us to operate with greater reliability and significantly reduced risk, ensuring the facility meets both operational and insurability requirements.”

STADLER’s long-standing relationships with Nehlsen and PreZero played an important role in the project. Having built previous plants for Nehlsen and collaborated on major recent projects with PreZero – including the Eitting and Sollenau facilities – the company brought both technical expertise and deep familiarity with the client organizations.

Reconstruction required close coordination between the three partners, external project management teams and insurance stakeholders. The process from incident to rebuild stretched over nearly three years, demanding persistence, detailed documentation, and joint decision-making at every step.

“During planning and installation, STADLER’s approach was communicative, open, and problem-focused, with a strong emphasis on keeping to the project schedule,” added Andreas Thiel. “Commissioning was more challenging due to coordinating subcontractors, which caused some delays. Despite this, the result was a high-performance facility capable of reliably meeting its sorting volumes.”

Following the completion of the SKN reconstruction project, Bremen is once again home to one of Europe’s most advanced light packaging sorting plants. The facility has been rebuilt to be stronger, safer and more forward-looking. The plant demonstrates how modern recycling infrastructure can evolve to meet rising safety demands while maintaining high throughput and output quality.

'Fire risks in light packaging sorting can never be completely eliminated,' concluded Wolfgang Köser, STADLER's sales director for Germany, Austria and Switzerland. 'With the measures implemented in Bremen, including structurally separated classification halls, monitored fire zones, sprinklers, and integrated fire suppression systems, the plant now operates at a significantly lower risk level and with much greater resilience. This project shows what can be achieved when long-term partners work together to rebuild not only what was lost, but also to create a facility that is ready to face current and future challenges.”