PhD defence Ali Ebrahimi

Keywords: Multilayer polyethylene films, Mechanical recycling, Polyurethane adhesives, Adhesive chemistry

"Design for Recycling of Lamination Adhesives in Multilayer Laminated Plastic Packaging Films"

This thesis investigates how multilayer polyethylene (ML-PE) films used in flexible packaging can be recycled more effectively into new films. Although these films offer a promising alternative to conventional packaging, the adhesives used to bond their layers can make recycling more difficult and reduce the quality of recycled materials.

The research examines how adhesive composition and film structure influence recycling performance. It shows that the type of chemicals used in the adhesive and their molecular characteristics affect how well the material melts, flows, and forms new films. By carefully selecting these components, the recycling process can become more stable, producing films with better strength, appearance, and overall quality.

The study also compares single-material and mixed-material packaging structures. It demonstrates that single-material polyethylene films are more suitable for recycling than films combining incompatible plastics. Overall, the findings provide guidance for designing recyclable packaging and support a more circular plastics industry by enabling materials to be reused in new packaging films.

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