A Clear and Pleasant Flexibility: The Supermarket and Flexible Films

You can learn a lot about flexible packaging trends by going to the grocery store. So let's take a walk.

Stroll down the pet food aisle and look at the sizes and shapes of packages and you see fewer and fewer paper bags of dry dog and cat food and more and more colorful flexible film containers from smaller size standup pouches to bags big enough to feed a kennel of Great Danes. A couple aisles over in the baking needs section, many mixes for cakes and muffins and brownies are also wrapped in flexo printed films. The purveyors of these products and more are increasingly eschewing paper and chipboard containers in favor of flexible packaging films.

"Flexible films are growing and continuing to grow," affirms Steve Crimmin, U.S. director of sales and marketing for RKW Dana Films. "And most of that growth is at the expense of rigid packaging like chipboard, rigid plastic, glass, metal. Flexible is hot and it's not going to cool down."

And it's not just in packages that hold an entire product. The use of films extends to wraps on bottles and to labels, especially in the food and personal care sectors.

"With continued growth of squeezable containers in the food and personal care sectors, we see a need to offer films with the squeezability of polyethylene and the superior print and conversion characteristics of polypropylene," notes Kim Hensley, product manager for MACtac Printing Products. "Squeezable containers require label materials that will accept deformation at low force and recover completely."

Look and Feel

With eight- and 10-color flexo presses being the norm for most flexographic shops, the ability to make what is basically a plastic surface look like just about anything you want is a key advantage of flexible films. "The versatility of these substrates is a big deal," notes Crimmin. "You can make a polyethylene container look like paper, and that can be part of the brand or product image."

Take Clif Bar for example. The energy/protein snack bar company wraps its products in an extruded film that looks much like a plain paper wrapping. Does this better entice core "outdoorsy" customers who may be more inclined to purchase a product wrapped in paper? Maybe. But the distinctive flexible wrapping stands out on shelves and conveys an image that's appropriate for the product and its market. Will the company next lose its chipboard boxes and put wrapped bars in flexible pouches? Time will tell, but don't be surprised if it does.

The No-label Look

Now head over to the aisle with personal care products. The containers may be rigid plastic but the labels are increasingly clear. The same is true for wine and spirits. Some of this is driven by cost and some by the desire to differentiate a product on the shelf. "The clear, no-label look is growing in popularity," affirms Hensley. "Many high-end products in the food, beverage/spirit and cosmetic markets are being packaged with a sophisticated no-label look. Brand owners want a crystal clear label material so that the product name and logo looks like it was printed directly on the container."

This does add a certain cachet, especially in clear containers, but for label printers it is not without some issues. The label and packaging industry is seeking ultra-thin facestocks and liners due to the potential for less waste and supposedly increased productivity. There has been movement from 2-mil to 1.6-mil BOPPs and from 1.2-mil and 1.5-mil PET liners to .92 gauge or even thinner. The challenge comes after the label is printed. "The transition to the thinner material is posing new challenges for diecutting," explains Hensley. "There is literally no room for error when diecutting the ultra-thin layers."

"Printing thin, unsupported films is more difficult than printing labels," agrees Bob Leahey, Associate Director at industry consulting firm InfoTrends. "Still, film suppliers have qualified many films, such as Tecra, for use as label face stocks. These companies will continue developing and supplying media for flexo and digital presses printing flexible packaging."

Choices, Choices

The diverse nature of packaging applications from food and beverage packaging to health and beauty packaging to pet food means that no one set of label properties offers the best performance and aesthetics for every application. Surface conditions, environmental conditions and usage are all factors in determining which substrate is most appropriate. For instance, does the label need to be applied to a unique bottle shape, a squeezable bottle or a textured bottle? What is the temperature and humidity during the label application? Is the label hand applied or machine applied? And how will the container be used: Indoors, outdoors, in hot, cold or moist environments?

"It's also important to consider more than just a label's facestock when choosing labeling materials," cautions Helmsley. "With the rising prevalence of various plastics in packaging applications for food, beverage, healthcare, cosmetics, cleaning products and more, it is important to know the chemical composition of the packaging to ensure an adhesive will stick to the package surface for an appropriate length of time."

One of the biggest drawbacks of polyethylene (HDPE and LDPE) containers, for instance, is poor adhesion for inks and label adhesives. This is usually due to chemical incompatibility and the inability of the ink or adhesive to "wet-out" the surface of the container. To remedy this, containers need flame or corona treatment to address the lack of wetting-out. Alternatively, hot-melt adhesives can be used on untreated containers.

Closing the Loop

One of the more consumer-friendly advantages of flexible containers is the ability to reseal a package. Today's busy lifestyles demand convenience packaging, and that often means resealable. "This can be a screw-top for liquids, sometimes with nozzles for easier use. Then there are versions of Ziploc seals and even a Velcro-like closure that needs only minimal alignment," said Crimmin. For now, resealable pouches are most often found on dry items like nuts and fruit, but this option is expanding. Tuna fish in a flexible pouch? Before long, that just might be the start of your basic tuna sandwich.

All in all, the range of flexible films is continuing to expand for both labels and many types of packaging. The range of options presents both challenges and opportunities to package printers and converters. All printers and converters can count on is having to adapt to change—which is nothing new—and look for opportunities to delight customers with exceptional printing on an ever-changing range of flexible films. pP