Barrier packaging plays a critical role in protecting products that are sensitive to oxygen, moisture, or ultraviolet light, particularly in industries like diagnostics or medical device manufacturing. Traditionally, there are two main types of barrier packaging materials, films and foils. But a third option, metalized film, has been rising in popularity and has been proven to have distinct advantages if selected as the material option for packaging sensitive products.
To choose the right barrier material for your packaging, first and foremost the packaging material must meet the barrier requirements for the product. Do you need to protect the product against oxygen? Is ultraviolet (UV) exposure a concern? Will moisture significantly impact the efficacy of your product? Understanding these requirements will then help identify the level of barrier that is required. Traditional multilayer laminations containing films, foils, and metalized films each have different barrier properties due to the amount of aluminum or aluminum oxide that is included within the material structure. For example, a film contains zero microns of aluminum whereas a traditional foil structure contains around nine to eighteen microns of aluminum and a metalized film might only contain 0.4 microns.
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Not only do metalized film and traditional foil structures contain vastly different quantities of aluminum, but the development process also varies. Foil is made using a standard adhesive or extrusion lamination process, with a solid layer of foil in between layers of polyester or Nylon. (You can learn more about this process in my previous blog A Film is not just Film). The metallization process, on the other hand, is unique. To create a metalized film, first, a layer of polyester or Nylon layer is placed into a vacuum chamber with a thin layer of aluminum. It then is exposed to high temperatures to evaporate the metal atoms from the aluminum. The evaporated metal atoms are then deposited onto the surface of the plastic film creating a thin, even layer of metal. This structure is then sent through the adhesive or extrusion lamination process to create a metalized film lamination. While the processes for foils and metalized films differ, they can look the same to the untrained eye. Therefore, it is important to understand their differences to properly choose which material protects the product most effectively.
If a metalized film contains the oxygen, UV, and moisture barrier property levels that are sufficient for your product, there are a few additional benefits to choosing a metalized film as well. These three additional benefits are part of the reason metalized films are becoming such a popular topic:
- Cost - With lower amounts of aluminum in metalized films compared to traditional foils, metalized films are often more cost-effective.
- Sustainability - Metalized films are much thinner than a traditional foil structure which can help in minimizing packaging footprint.
- Printability - If print on the packaging is crucial for usability, a metalized film often shows the ink and graphics better.
For highly sensitive products or if you are unsure of the barrier requirements of your product, a traditional foil is always going to be the safest. But if you need barrier packaging without the significantly low barrier properties of a foil or are looking to improve your carbon footprint, metalized film is an option.
