Smart label signals expiration

Arm & Hammer® baking soda is probably one of the most recognized brands for household deodorizing and cleaning, baking and body care, and for years, its manufacturer, Church & Dwight, Co., Inc., Princeton, NJ, has worked to ensure that every household carries several boxes of the branded sodium bicarbonate to meet these varied household and personal-care needs. However, when it came to its refrigerator and freezer deodorizer product, the company needed a way to remind consumers to regularly replace the air freshener for maximum odor absorption.

The solution came in the form of a new product called the FridgeFresh™ Refrigerator Air Filter, a circular, plastic, flow-through air filter that can be attached to the inside wall of the refrigerator/freezer and includes a temperature-controlled label that clearly indicates when it's time to replace the product.

The technology was presented to Church & Dwight by a proprietary, independent patent holder and was developed into a functioning label construction by converter WS Packaging Group (www.wspackaging.com). Explains Todd Ostendorf, corporate marketing manager for WS Packaging, “Using the ink technology created by this individual, we built a label construction that allows the ink to function in a way that the label becomes an indicator.”

He adds that the greatest challenge in creating the label was to control the migration of the ink and to produce the solution in an affordable and cost-effective manner. “There are some other timer technologies out there, and we looked at some of those,” he says, “but none of them were economically feasible for a packet of baking soda.”

Key objectives of the project were to make the label highly functional and easy to use. It also had to physically be part of the product casing, but not interfere with the functionality of the air-filter device. The FridgeFresh label consists of a white bar that is enabled by the consumer when they remove an activator strip. As time passes, a chemical reaction between two, microencapsulated inks in a cold temperature causes a pink color to migrate across the label. When the bar is completely pink, it is time for the product to be replaced—after three months when in the refrigerator and after six months in the freezer.

The pressure-sensitive labels are produced in a single pass on a flexo press at the WS Packaging facility in Neenah, WI. The construction consists of the label material, the proprietary inks, a separation strip and a top ply.

“We took the label to market in less than two months,” says Ron Hagen, research and development manager with WS Packaging. “Church & Dwight had an established time frame for launching its new FridgeFresh Refrigerator Air Filter. We had to meet that deadline with a fully functioning label, despite the technological hurdles of engineering a multi-ply construction that had never been done before.”