Multimaterial
Last updated
Last updated
Multimaterial food packaging combines layers of different materials to achieve specific protective functions. A typical example is the beverage carton, which contains about 75% paperboard for stability, 20% plastics (usually polyethylene) to prevent leaks, and up to 5% aluminum to protect against light, oxygen, and chemical migration. Other examples include pouches, tubes, and trays made from laminated films of plastic and aluminum, often found in the form of metal-coated cardboard. Adhesives and printing inks are also integral components, ensuring functionality and branding.
Multimaterial packaging, composed of two or more materials, can contribute to resource depletion and pollution. However, their main drawback is related to recycling difficulties (see below).
Chemical migration in multi-material packaging primarily depends on the material directly in contact with food. However, substances from outer layers, adhesives, or printing inks can also penetrate into food if no adequate barrier exists to prevent chemical migration. The phenomenon known as ‘set-off migration,’ can also occur during production when packaging materials are stored in reels (or final products are stacked inside one another), causing chemicals from the printed exterior to transfer to the food contact interior.
Multimaterial food packaging presents significant recycling challenges. Its layers, though thin, are difficult to separate, which complicates the recycling process. Beverage cartons, for example, can undergo fiber recovery during recycling by separating the paperboard from plastic and aluminum layers. However, the remaining composites are downcycled into lower-quality products like plastic pallets. Laminated films, made of plastic and aluminum, are even harder to recycle, and recycled materials from such packaging are not used in direct food contact, limiting the potential for closed-loop recycling.
Most multi-material packaging ends up being incinerated or landfilled. Efforts are growing to improve recycling technologies for this type of packaging, but the complete separation of materials and reuse in food packaging remains out of reach. This downcycling means that multimaterial packaging cannot yet contribute to a truly circular economy.
If you want to learn more about multi-material packaging, please visit the pages linked below.
