Stadler’s ‘biggest ever line’ to handle half of Denmark’s PET bottles

Recycling technology provider Stadler has completed the commissioning of a beverage packaging sorting plant it designed and built for Dansk Retursystem in Taastrup, Denmark.

With a capacity of 110 m3 per hour, it is expected to process 55% of Denmark’s recycled cans and PET bottles. It will handle more than 25 000 tonnes of material annually, operating 16 hours per day across two shifts for 300 days a year.

Private-public initiative

Dansk Retursystem is a non-profit company owned by Danish breweries and regulated under the Danish Environmental Protection Act. Founded in 2000, it operates the country’s deposit and return system for beverage bottles and cans.

Dansk Retursystem is seen as a good example of a successful collaboration between the private and public sectors. ‘Its business model creates a circular economy that involves the entire chain: beverage packaging manufacturers, breweries, retailers, consumers, transport companies and sorting recycling companies,’ it explains.

Bottles and cans are collected from reverse vending machines at 3000 retailers, shops, offices, cafés and restaurants across the country and from deposit return banks in 12 cities. Nine out of ten bottles marked for deposit are returned and recycled.

Magnets and Near Infrared

For sorting solutions specialist Stadler, it is ‘the biggest line’ the company has ever designed and built. Assembly started in November 2019. The facility uses magnetic separation to sort aluminium cans, ejecting any ferrous materials, and near infrared (NIR) technology for PET bottles.

The removal of loose labels is also part of the process. At the end of the process, balers compact the aluminium cans on one output line and PET bottles on the other.

Challenging job

According to joint project manager Armin Winand, the line presented particular challenges due to the high level of automation. ‘This is a fully automated sorting plant with a high throughput. We addressed this at various stages of the process with extra-large intermediate bunkers with a capacity up to 240m³ and a similar capacity bunker conveyor 20 metres long, four metres wide and four metres high. At the end of the process, the aluminium and PET bales are transported automatically into the storage area.’

Management of the unloading of incoming materials is also automated, with the system indicating to the delivery drivers into which of five bunkers they should unload. The plant is also claimed to have the flexibility to allow customers to select different operating modes according to their requirements.