Laser-scored pouch stands up under testing

When preparing to commercialize newly developed, boundary-pushing food-packaging structures, packaging suppliers must engage in a significant amount of testing before the first sales pitch is even made. Recently, U.S. standup pouch provider Ampac Flexibles, Converted Products Division (www.ampaconline.com) needed to test a new laser-score feature it had developed to provide packagers with an easy-opening option.

While many converters and food manufacturing plants usually have some on-premise analysis capability, there are many tests that are not run frequently enough to justify the required capital expenditure for specialized instrumentation equipment. This is the situation in which Ampac found itself, so the company hired Mocon, Inc. (www.mocon.com) to provide the necessary testing services.

Ampac Flexibles, a division of Ampac Packaging LLC, is a diversified, flexible packaging company with nine operating sites in North America and Asia, including the standup pouch operations of the recently acquired Kapak Corp. The company's converted products division offers up to 10-color flexo and eight-color, two-sided gravure printing, solvent and solventless laminations, and a wide variety of custom and stock premade pouch designs with laser scoring, fitments and zippers.

In order to provide leading-edge pouch technology, Ampac recently invested in a laser suitable for scoring nonretort laminations. Laser-scored pouch laminations tear across neatly and provide an attractive, parallel, front and back opening.

"Films don't always tear in a linear fashion," explains Tobin Haas, director of technical services, Ampac Flexibles, Converted Products Division. "Frequently, the user is left with a jagged or nonparallel front and back edge. From a marketing perspective, this is usually unattractive and can result in product spills—particularly if the package contains more than one serving and is meant to be reclosed."

During scoring, when the laser penetrates a lamination that contains both transparent and nontransparent layers, the laser is absorbed by some layers and not by others. The key is to affect the structure so that it provides a clear tear across the affected path, but not to the degree that the barrier properties of the package are compromised.

Because of the potential for the barrier to be affected during scoring, before Ampac began promoting the easy-open capability to packagers, it wanted statistical data that would show that the benefits of laser scoring could be introduced without disturbing the lamination's barrier properties. That's when it turned to Mocon's testing and consulting laboratory.

Primarily known for its testing instrumentation—which includes permeation, gas and headspace analyzers; aroma and off-odor instruments; gauging instruments; leak and burst detectors; seal strength testers; and other equipment—Mocon also offers testing and consulting services.

According to Mocon, although there are many analytical service options available to packaging professionals, its laboratory can provide a unique perspective because the tests it performs are conducted with instrumentation that it has manufactured. Equally as important, the company adds, is that it understands the science of developing and interpreting test data, which puts it in an exceptional position to perform and interpret tests with confidence and accuracy.

In addition, because it develops testing equipment, Mocon notes that it can test customers' packaging with the very latest instrumentation, including units that have not yet been commercially released.

"Our facility not only houses the largest permeation test lab in the world, but also the most sensitive and repeatable equipment available," explains David Farmer, account manager for Mocon. "The other thing that distinguishes us is that we don't limit ourselves to oxygen and carbon dioxide testing. We can test virtually any permeant, through any barrier."

Mocon also follows the parameters set by ASTM Intl. (www.astm.org) standards, so that data is comparable from one lab to another or from converter to packager. According to the company, its permeation units are the only instruments that comply with ASTM D-3985 and F-1927 standards, which are, respectively, the Standard Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using a Coulometric Sensor, and the Standard Test Method for Determination of Oxygen Gas Transmission Rate, Permeability and Permeance at Controlled Relative Humidity Through Barrier Materials Using a Coulometric Detector.

Mocon's testing and consulting services for films or finished packages (flexible, semi-rigid or rigid) include:

In Ampac's case, Mocon tested a variety of pouch structures and thicknesses over a period of several months for both oxygen and moisture vapor-transmission rates.

"Basically, we challenged the pouch by introducing the permeant to its exterior," Farmer explains. "Then we swept off the inside volume and sent it to a detector, so that any oxygen or moisture vapor that found its way into the package was measured. That's how the total permeation was calculated."

The end result for Ampac is that positive test data now enables the company to discuss with its customers the benefits of laser scoring, armed with independent statistics. "We now have the data that will allow us to offer packagers the latest easy-opening feature for standup pouches," Haas says. "This enables us to offer structural alternatives that not only achieve desired barrier parameters, but also provide consumers with a more attractive, more functional way of accessing the contents."

Further, the company was able to execute the testing without spending capital expenditure funds on equipment that would be used infrequently.

"It really boils down to the quantity," Farmer relates. "If a company has a significant amount of testing volume, then it typically makes more sense to purchase the equipment. But it's usually not a good idea to buy equipment if it is going to sit idle for most of the month."

Sometimes a company with its own testing capability will choose to have testing done externally just for the added credibility or to meet increased throughput needs that can be provided by an independent lab.

"In many cases, a client may not be using the proper barrier for their product," Farmer explains. "That's when they can work with our consulting services to help determine exactly what is required. For example, if the packager requires a sixty-day shelf life, and the test data shows that their packaging is providing a 120-day shelf life, fine-tuning the structure can result in cost-savings. Conversely, if they are under-packaging and providing a thirty-day shelf life when they really need sixty days, our data will help direct them to an improved structure.

"By outsourcing the package evaluation process to Mocon, packagers can shorten their 'speed-to-market' cycle with a high degree of performance confidence."