Interfacial separation and characterization of Al-PE composites during delamination of post-consumer Tetra Pak materials

Abstract

BACKGROUND: In order to understand Al-PE composite delamination during the separation process, interfacial separation and characterization of Al-PE composites during delamination were analyzed. The aim was to enrich the present theoretical analysis of Al-PE separation and to provideg new ideas for the recycling and reuse of post-consumer Tetra Paks. RESULTS: The composites delaminated into three layers, but the times for delamination of the two plastic layers were different. After separation, some plastics were present in the separation solvents analyzed by FTIR. Bright spots of unregular particles with scattered distribution on the surfaces of the three layers were Al, O and C, detected by SEM-EDS. CONCLUSIONS: During the separation reaction a mixed solution permeates into the interfaces of Al-PE composites; adhesive structures of the PE layers were destroyed and even dissolved into particles, thus interfacial adhesive failure and Al-PE separation occurred. However the different properties of the adhesive layers and the oxidation degree of PE fragments cause different separation speeds of the two interfaces adhered to each side of the Al foil.