Empirical Evidence

Or: Every good packaging feasibility test I needed to know, I learned in kindergarten.

By Nick G. Fotis, Director of Packaging, Cardinal Health


Early prototyping is important to package design and development. AAMI Technical Information Report 22, “Guidance for ANSI/ AAMI/ISO 11607, Packaging for terminally sterilized medical devices, Part 1 and Part 2: 2006,” in Section 10.1 suggests that sterile barrier systems should undergo a design feasibility evaluation. These engineering tests evaluate the system at the prototype stage.

Before you get to this point, however, you could screen potential materials quickly, right at your desk or in your conference room. At the risk of seeming unscientific, I’ve found a few methods to sort out the options.

These manual tests offer experiential insight into material or package properties. Perhaps one approach will save weeks of development effort or expensive lab testing. For more test methods, visit www.pmpnews.com for the expanded article.

Cross Pen test: This test often is used when a supplier passes around a new film sample. You’ll see all the engineers in the room immediately reach for their pens. Almost in unison, they place the top of the pen against the middle of the film and try to push the pen through. They get an immediate tactile feedback of the relative toughness and elasticity of the film. This seems to be addictive, as they can’t seem to stop at just one pen-top puncture, but often repeat the process throughout the rest of the meeting.

The Hole-in-One test: Similar to the pen test, the hole in one is used by the engineer to try to put a hole in the film. First coined and demonstrated years ago at an MD&M show by a very creative marketing bloke, this quick extensibility and toughness test has left hundreds of protruding ghosts of finger-shaped films on the tables of empty, dark conference rooms after meetings. It also has probably resulted in a lot of sharp pointed devices remaining in their sterile barrier system without compromise of package integrity, due to the early detection of superior puncture properties.

Whack test: This popular test for rigid trays can be done on the empty tray alone or, better yet, on a sealed tray with product inside. Step One: Grab the tray firmly with two hands (close to one end of the tray). Step Two: Whack it on the edge of your desk. Step Three: Examine for cracks in the tray, burst seals, or products poking through the Tyvek or other lidding material. The test may be repeated if desired until failures are observed or the person in the cubicle next door starts complaining.

The Point Lorimer test: Named for a clever technician and engineer, this test quickly measures abrasion resistance of film. Take a small square of film (about 2 ¥ 2 in.) fold it in half, then in half, at 90°, once again. Insert your finger into the pocket created. Add a couple of drops of water. Now rub the point of the folded film back and forth on the back of a pad of paper or on the nearest corrugated box. Count the number of strokes until evidence of leaking water turns the corrugated a darker color of that beautiful kraft brown that all packaging engineers have grown to love.

Stargazing: This test was taught to me by a packaging engineer who loved packaging so much that he named his kids after boxes: Casey and Corre (for corrugated). To determine the potential for foil pouches to lose barrier, pouches can be either wadded up and unfolded or put through simulated distribution testing. Afterward, open the pouch, remove the product and bring the final pouch up to your eyes so close that it touches your nose and forehead. Look into the darkened pouch for constellations of stars where the foil has flex-cracked or the pouch has pinholed. This test may also be done for about 15 minutes in the afternoon if the engineer needs a refreshing rest.

Jack the Pouch-Ripper: Often, an engineer grabs at a pouch and quickly jerks it open in less than a 10th of a 10th of a millisecond, with enough force to make up for a lack of BowFlex workouts. This pouch-ripping test is a great way to see how the package might perform in real life, such as when ER nurses rush to get the product open or ambulance drivers open it with one flap in their mouth and the other with their only free hand.

Stress Mark Fold: If you check out a new rigid thermoform material, there is no need to wait for distribution testing to see those stress marks. Just take a small piece, fold it over and fold it back to see if you can make a beautiful stress-whitening line. Although these marks almost never impact any functionality, they can be the kiss of death from marketing.

Nick G. Fotis, currently Director of Packaging at Cardinal Health, collects easy-to-use, quick manual screening tests. He claims this is a less expensive hobby than golf. If you have a test method you would like to share with him, he can be reached at nick.g.fotis@cardinalhealth.com.

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