An Adhesion Improvement of Low-Density Polyethylene to Aluminum through Modification with Functionalized Polymers.

An interfacial adhesion improvement between low-density polyethylene (LDPE) and aluminum (Al) foil is an important challenge in designing multilayered packaging (TetraPak packaging type) due to insufficient inherent adhesion between both untreated materials. Therefore, extra adhesive layers are often used. The hydrophobic character of LDPE is responsible for poor adhesion to Al and can result in delamination.

Enhancement of Adhesion Characteristics of Low-Density Polyethylene Using Atmospheric Plasma Initiated-Grafting of Polyethylene Glycol.

The low-density polyethylene/aluminum (LDPE/Al) joint in Tetra Pak provides stability and strength to food packaging, ensures protection against outside moisture, and maintains the nutritional values and flavors of food without the need for additives in the food products. However, a poor adhesion of LDPE to Al, due to its non-polar surface, is a limiting factor and extra polymeric interlayers or surface treatment is required. Plasma-assisted grafting of the LDPE surface with different molecular weight compounds of polyethylene glycol (PEG) was used to improve LDPE/Al adhesion.