The demands placed on the looks of plastic packaging are high, as colourful packaging is a critical factor in the decision to buy. At the same time, consumers highly favour the use of recycled materials. But until now, it has been practically impossible to turn colourfully printed plastic packages into colourless granules. Five business have now found a solution together.
Partnerships often lead to ground-breaking developments in the world of packaging. For example, five businesses have cooperated to develop a stand-up bag with a special oxygen barrier and de-inkability to remove colour and coatings. Thanks to the use of a printable barrier coating, the bag is suitable as packaging for a wide variety of filling goods. Using a suitable primer also allows for delaminating and de-inking the laminated structure. This means that both the printed colour and the oxygen barrier can be completely removed and the packaging can then be recycled into almost colourless PE granules. This makes the granules available for a broad range of applications which require higher-quality recyclates. The mono-material foil bag made of polyethylene has similar properties to a standard, non-recyclable multi-material stand-up bag.
The new foil packaging uses the newest polymers, printing colours, functional coatings, adhesives and processing technologies by the partners ExxonMobil, Henkel, Kraus Folie, Siegwerk and Windmöller & Hölscher. The concept also appealed to the jury of the German packaging award Deutscher Verpackungspreis. Gold was awarded in the category “Sustainability for recyclability/Design for recycling”. “This technology, which now enables laminated materials with inside printing to become high-quality recyclate in material recycling, is a milestone on the path to a functioning circular economy”, says the jury in their statement. By using a highly effective printed oxygen barrier in combination with a novel primer for delamination and de-inking as well as an adhesive certified for this process, the partners intend to produce a PE mono-material packaging with internal barrier and colour layer that meets the highest demands and becomes transparent mono-material PE again during recycling after an alkaline watery hot wash, which is already standard during PET treatment.
Information on the technical details: This project used the delamination and de-inking primer technology by Siegwerk on a flexoprinting machine and a downstream aggregate (Miraflex II) by Windmöller & Hölscher. The oxygen barrier properties were achieved by single component barrier coatings by Siegwerk (“Cirkit OxyBar BC 1582”) and by Henkel (“Loctite Liofol BC 1582 RE”). The stand-up bag itself is made of the newest generation of Exxon Mobil’s high performance polyethylene (like Exceed S and Exceed XP) in combination with Exact materials in the sealing layer. The MDO PE foils were developed by ExxonMobil and Kraus Folie and produced on the latter’s Varex II extrusion system featuring an inline MDO unit.
