Recyclable High Barrier Film with Tie Layer

Executive Summary

Flexible plastic films are used extensively for packaging applications. Increasingly there are consumer, company and government demands for better end of life products to minimize landfill waste. However, often these more eco-friendly products have poor mechanical or barrier properties and are not suitable for recycling. Researchers at Michigan State University have recently developed a film technology that offers good barrier properties and is amenable to both chemical and physical recycling.

Description of the Technology

The technology is based on a unique tie-layer adhesive composition that that allows excellent adhesion between polyester film layers and polar oxygen barrier layers such as EVOH. Various multilayer film combinations have been made with this tie-layer in a cast film extruder including films with PET, PBS, PBAT and EVOH oxygen barrier and tested for barrier properties. In addition, the multilayer films were chemically recycled  via depolymerizing the polyesters and recovering the EVOH.

Benefits

• Excellent interlayer adhesion even after annealing
• Excelent barrier properties. Technology can achieve  <0.15  ± 0.001 WVTR at  90%RH and 23^oC  and <0.05 ± 0.01 stretched OTR  at 50%RH and 37^oC.
• Can be extended for biodegradable, biopolymer and compostable film layers
• Does not interfere with the chemical recycling of polyester films
• Cost is comparable or lower than that of conventional EVOH multilayer films.

Applications

• Packaging films for food

Patent Status

• Patent pending

Licensing Rights

Full licensing rights available

Inventors

Dr. Muhammad Rabnawaz, Dr. Mohamed Abdelwahab, Mohamed Abdelwahed

TECH ID

TEC2024-0157