Werner & Mertz closes the loop

For the first time, Frosch household cleaners come with a fully recyclable mono-material packaging.

It is not easy to manage „green“ – or in a cycle. But by turning the traditional approach to product design upside down, the Mondi Group and Werner & Mertz GmbH, a German manufacturer of cleaning products, achieved a breakthrough: the development of a fully recyclable mono-material packaging for Frosch brand cleaners. However, the brand owner and the packaging manufacturer realised that they could not do this on their own.

EPEA Switzerland GmbH, an accredited general assessor for Cradle to Cradle Certification™, joined the project team to assess the quality of different materials considered for use in recirculation and chemical recycling applications. The cyclos-HTP Institute for Recyclability and Product Stewardship ensured that these materials would work within existing recycling structures and across their extended life cycle. The Green Dot – Dual System Germany finally researched and confirmed the potential market value of the resulting recyclates.

Learning by Doing

In almost four years of working together, the team laid the foundation for the development of a 100% recyclable stand-up pouch. The new bag – with an easily removable printed sleeve – is subject to the criteria of the strict Cradle to Cradle Certified™ guidelines. Albin Kälin, CEO of EPEA Switzerland, describes the innovation process for the new frog bag as „quite radical, with learning by doing like never before“. Werner & Mertz wanted a real solution, not just a package claiming to be „more sustainable“ that would end up in landfill or incineration.


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All packaging, explains Joachim Christiani, co-director of cyclos-HTP, must make it through a complex sorting process – identifiable by infrared scanning. Flexible packaging, which often consists of a multi-layer composite of different, incompatible materials, tends to be more difficult to recycle. The Institute was involved early in the project with recommendations on packaging design, suitable materials and available sorting and recycling facilities in Europe.

Groundbreaking innovation

The partners involved in the project also had to solve the problem of recycling printed plastics. This consideration eventually led to perhaps the product’s most groundbreaking innovation, its two-piece construction: the pouch itself and the detachable banderole for front brand details and consumer information on the back. „We finish the bag with an eye-catching, sales-promoting outer sleeve,“ explains CEO Reinhard Schneider of Werner & Mertz. „And if the bag is empty, we simply ‚undress‘ it in an automatic process that shreds both components and sorts them into separate material streams.

Around 85 percent of the entire packaging material (low density polyethylene, LDPE), including the spout and lid, is unprinted. This means the material can be recycled without loss of quality. But even the remaining 15 percent is fully recyclable, as it is free of adhesives and bonding agents. The bag with pouring opening and punched handle consumes about 70 percent less material than rigid plastic bottles with the same capacity.

After the project partners had decided on a suitable design and preferred material for the product, „Der Grüne Punkt“ investigated the potential reusability and the real market value of such recyclates – to ensure the economic feasibility of the planned product in this respect as well. From late summer 2019, when the „recipe“ has been taken over, Werner & Mertz and Mondi will transfer these concepts from the drawing board to the „kitchen“ and start production of the bag on a new production line specially purchased by Mondi for this project.