Metallized (MET) films encompass biaxially-oriented polypropylene (BOPP), polyester (PET), nylon and cast OPP, and are manufactured by means of high-speed vapor deposition. In this article, the focus is on metallized BOPP and PET. The quality of the base film and the integrity of the metal coating process are critical for the success of an application. When those fundamentals are in place, metallization can significantly improve the oxygen and moisture barrier durability of a film, make for an opaque barrier to light and offer a high-reflective, glossy appearance.
A popular MET OPP application is for salty snacks, oatmeal, hot cocoa, seasonings, dried soups, rice, dried cheese, mixes and powdered beverages. It is also sought after as a replacement for foil in packaging structures for nutritional bars. MET PET film is an ideal foil-replacement solution for coffee, nuts, dried fruits and powdered nutritional or energy drink packaging. It’s also an excellent choice for replacing foil in a lidding application for dairy foods, like yogurt and ice cream, though challenges may present themselves depending on the filling equipment used.