The U.S. Army, U.S. Marine Corps, and U.S. Air Force consume approximately 46.6 million meals in the field in an average year, generating approximately 14,000 tons of waste per year (0.66 lbs of packaging waste per individual per meal). Current packaging uses multi-layered materials containing foil as the barrier between the heating mechanism and the food. The waste generated is difficult to recycle and biodegrade. If Meal, Ready-To-Eat (MRE) packaging material were more recyclable or biodegradable, ration waste could be significantly reduced.
The objective of this project was to research and develop a nanocomposite packaging material that would eliminate the need for a foil barrier, thus reducing the amount of solid waste associated with military rations and packaging. These environmentally friendly nanocomposites were expected to meet the operational and performance requirements of combat ration shelf life.
A promising class of nanoscale materials is made from montmorillonite clays intercalated with organic polymers. Montmorillonites are silicate materials arranged in thin sheet-like layers. Each layer of clay is approximately 1 nanometer (nM) thick and 100 to 200 nM long. The ability to intercalate organic polymers between the layers of the clay imparts the unique properties to the composites. Montmorillonite has been shown to reinforce plastics, increase barrier properties, improve dimensional stability, increase heat distortion temperature, and increase flame retardancy. Montmorillonite nanocomposites were studied for potential use as biodegradable food packaging. In addition to increased vapor barrier properties, the presence of the clay in biodegradable nanocomposites could result in increased thermal properties of the polymer as well as enhanced biodegradation rates in selected composites. Melt processing parameters for the polymer/nanoclays were explored to obtain the optimal dispersion and interaction to improve properties.
Implementation of a nanocomposite packaging substitute will reduce the solid waste associated with use of current MREs. In this project, current materials in the existing combat ration packaging systems were replaced with recyclable or biodegradable nanocomposites that have improved properties and the potential to reduce the cost of military packaging. (Project Completed - 2006)