Up to now, multi-layer packaging systems, which consist of different types of polymer material, have been considered unsuitable for mechanical recycling of the raw materials as the material mix cannot be separated, which in turn would be necessary to ensure recycling by type. One solution could be monomaterials, but for some packaging types a material mix is needed due to the different functionalities of the polymers. Therefore, the entire industry is faced with a major challenge, especially when looking at the European Green Deal, which requires all packaging to be reusable or recyclable to a certain minimum level by 2030. This shows that the demand for sustainable and recycling-friendly packaging is huge.
Together with several partners along the value chain, BASF is looking at various options that involve the use of adhesives to achieve sustainable packaging solutions.
In a first pilot trial it could be shown that PET/PE laminates produced by using a newly developed water-based acrylate adhesive could be separated in a standard industrial washing process for PET bottles with hot alkaline washing solution. This debonding process was followed by a separation of the materials according to the different types by density gradient.
Co-author(s): Kresimir Cule, Dr. Peter Preishuber-Pfluegl, Dr. Saskia Groeer