By 2030 all plastic packaging placed on the EU market should be recyclable or reusable. This is according to the European Strategy for Plastics in a Circular Economy made by the European Commission.

Flexible plastic packaging is a growing segment in the packaging industry and flexible packaging made from monomaterials will most likely play a significant role in order to reach the European 2030 goal.

Laminated structures

Flexible packaging films are often a laminated structure consisting of several materials where each of them fulfils specific property demands. Laminated structures typically comprise a printing layer and a sealing layer. The printing layer in conventional packaging solutions is often a PET film and the sealing layer is often a multilayered polyethylene (PE) film comprising different materials, including polyethylene and barrier polymers. The main benefits of the PET layer are stiffness, thermal stability and transparency as a reverse printed surface layer which is common for various stand up pouch packaging solutions.

Recyclability

These laminates are however not recyclable and the industry is intensively developing alternatives. One target is to replace the PET layer with a polyethylene layer to provide a monomaterial, full polyethylene, solution.

MDOPE development

MDO (Machine Direction-Oriented) technology enables the production of oriented stiff PE films which fulfil much of the PET performance. The MDO line consists of a series of heating, stretching and annealing steps. This additional processing of multilayered PE films introduces property enhancements and allows thickness reductions which are both beneficial for the purpose of sustainability and recycling. The development of such polyethylene layer is challenging with respect to achieving both the processability and target properties. This requires excellent base resins and optimum recipes.

Norner invested in an industrial MDO pilot line from Hosokawa Alpine already in 2009. Numerous projects have been run on this line for raw material bench marking as well as application and recipe development. Several project results have been presented on international conferences including MDOPE for VFFS applications and shrink films. The first experience with laminates was made almost ten years ago. The technology centre in Norway is well equipped with film extrusion lines and test methods for film performance and film analysis.