Improved zippers are on the fast track: sliders and other enhancements make zippers easier to use for both packagers and consumers

Food & Drug Packaging, April, 2002 by Pan Demetrakaes

For the consumer, opening up flexible packaging used to be, in a minor way, like opening Pandora's box: It led to problems.

If the product wasn't consumed all at once, the package could be resealed in one of two ways: with consumer-supplied tools like tape or clamps, or with a reclosable feature that often was significantly more frustrating and less reliable than closures for rigid packaging.

But design advances have led to closures for flexible packaging that are much more versatile, reliable and secure than they used to be. In terms of both application by the end user and use by the consumer, flexible closures have made great strides.

SLIDE INTO SALES

Closures for flexible packaging take various forms: spouts, pumps, snapshut fitments and more. But the most common by far for U.S. packaged goods is zippers.

Perhaps the most prominent recent advancement for zippers is the slider. One packaging supplier's consumer surveys show support of upward of 70% for zipper closures. Introduced to consumers by Pactiv Corp. as the OneZip reclosable storage bag in 1993, slider zippers have caught on in a variety of consumer products.

Probably the most visible user of Pactiv's Slide-Rite slider zipper has been Sargento Foods. Sargento, a cheese converter and marketer based in Plymouth, Wis., introduced 12- and 16-ounce pegged pouches of shredded cheese with the Slide-Rite to the market in January 2001. Full conversion to the Slide Rite, on all 5 and 8 ounce shredded-cheese pouches, took place last August.

The results have been all that Sargento hoped for, says Brad Rostowske, director of new product development. In the last six months share growth has met or exceeded expectations. A large part of the credit has to go to the Slide-Rite closure, according to Rostowske.

"I'd say the slider is the product point of difference that helps the business," Rostowske says. "Shredded cheese has been growing in the 6% to 12% range annually for the last 10 years, and innovations are driving that category growth."

SALTY SNACKS A SNAP

Another innovative flexible-packaging closure, just starting to come onto the market, is specifically designed for vertical form-fill-seal applications: It's formed right along with the pouch it's attached to.

The Easy Snap closure system, introduced at Pack Expo 2000, uses a zipper track that works on the same principle as pre-made zippers. But the male and female halves are actually formed at the time the bag is sealed, from a strip of material that is laminated to the film as it unwinds. A feature press in the sealing jaw area of the filler molds the male side into an arrowhead design, forming a track that seals more reliably than a pre-made zipper. The materials and machinery for Easy Strip are made and distributed by SIG Doboy Inc. and marketed by Presto Products Co.

The first salty-snack application for the Easy Snap will appear on store shelves May 1. Herr Foods Inc. will feature it on bags of bite-size and thin pretzels.

Consumers have long indicated that they want reclosable packaging for salty snacks, but the industry has been reluctant, says Daryl Thomas, Herr's director of marketing.

Use of the Easy Snap will drive up the price of the product from $2.89 for a 24-ounce bag to $2.99 for a 22-ounce one--an increase of 13% on a per-ounce basis. But Herr's research indicates that consumers will be willing to pay the difference, Thomas says.

KEEPING THE TRACK CLEAN

Other zippers have hit the market that try to alleviate another common consumer complaint: interference from debris in the track. This is especially a problem with powdery products like flour and sugar.

The Powderproof from Minigrip/Zip-Pak features "evacuation ports" at the back of the female half of the zipper; particulates lodged in the zipper track are pushed through these holes when the zipper closes. The Style 140 Clog Resistant zipper from Presto Products Co. uses a double-track design, with extra space between the male and female halves. This space either allows particulates to fall out before the zipper is closed, or lets the zipper close around them.

Another innovation is the ArrowSlide zipper system for large bags, from MDH Packaging Corp. The ArrowSlide is being marketed for bags from 3 to 50 kg that carry dry, granular products such as pet food, bulk foods, chemicals and feed supplements. The ArrowSlide is designed not to open from the inside or pop off its zipper during bottom filling, and does not require new machinery or upgrades to existing ones, says MDH Vice President Alan Eads.

At a minimal cost, zippers and other reclosable devices have the potential to add value to a package and help distinguish it from competitors.

MDH Packaging Corp.
859-746-0993; www.ripnzip.com

Minigrip/Zip-Pak
815-468-6500; www.zippak.com

Pactiv Corp.
847-482-2000; www.pactiv.com

Presto Products Co.
800-265-0750;
www.prestoproducts.com

SIG Doboy Inc.
715-243-2543;
www.sigeasysnap.com

RELATED ARTICLE: Zippers and form-fill-seal: when to apply them?

A packager who wants to use zippers in conjunction with form-fill-seal equipment has two basic choices: apply them in-line or use film with the zippers pre-applied.