Rollstock film for flexible packaging has attributes and advantages beyond simply serving as a product container. Flexible packaging typically has multiple layers of film with each layer being responsible for one or more properties and protection.
Rollstock film can be metalized with a thin layer of aluminum to provide various levels of protection or application depending on the product and its requirements. There are several advantages to rollstock. For example, does the product require dimensional stability and need to stand up on the shelf at the point of sale? Does it require package integrity like a resistance to puncture and tear strength?
Shelf life is another consideration when considering the metalized film. What is the oxygen transfer rate required for the product inside? This is the OTR and the measure of how well the film structure will prevent oxygen loss. No one wants stale chips or trail bars! Another shelf life consideration is the water vapor transfer rate (WVTR ). This measures how well the film structure will keep moisture in, or out of the actual bag. The third consideration is the aroma barrier. This is the ability of the film to contain the product’s scent. This is very important in food-grade packaging.
Metalized film is simply a thin layer of aluminum to provide a greater barrier when needed for the considerations above and others. It has a high barrier at a medium price point when required. For example, a ziplock plastic bag does not require a high barrier but often the package for a food product does. Typically polypropylene and polyester are films that are metalized by they are also used in non-metalized packaging and printing.
The advantages of the metalized film are many. Compared to foil it creates a higher barrier at a medium price point where the foil is its own layer of material providing the highest barrier but at a higher cost. In comparison to standardized, or non-metalized films it’s cheaper but with less of a barrier.
Metalized films can be used in the applications and content of potato chips, nutrition bars, cookies, bakery, health, and beauty products. The difference is the cost which is based on the material cost and driven by the performance values required in the package itself.
Producers must ask themselves if the potato chips will go stale in 8-16 weeks? Will the moist-towelette stay wet in the single service package or will it dry out when the customer needs it to clean their hands?
Will the fat in a food product oxidize, or bacteria grow inside the package, potentially causing a health risk to the consumer? These are important questions the manufacturer must address with their packaging and printing company.
At Century Printing and Packaging, our metalized film runs with an added part to our Corona Treater allow us to treat this type of film for better printability and ink adhesion. Metalized film can run at faster speeds than foil increasing productivity for a greater ROI and high-quality sealing.
Having the ability to run short volumes of a film which is good for the slow movers of a product family, seasonal items, and test marketing is an advantage. Combined with medium and large volume capability, we are a great fit for companies using printed rollstock film.
Ben Waldrop
President
Century Printing & Packaging
Greer, SC 29651
800.344.7509