Flexible

Closures You Can Count On

Posted: December 14, 2009 by
Noel Jeffrey

Resealable flexible packaging has been around for a long time, but innovations in closure technology that reduce cost, cut production time, and increase quality keep the door open to new and improved applications. Zippers and sliders can close stand-up pouches and pillows at the bag's top, bottom, side, or front panel. And there are alternative resealable closure systems on the market as well. As for product categories, there seems to be no barrier to application for lawn and garden, agriculture, pet food, frozen food, personal care, baked goods, dairy/deli, candy, cookies, crackers, snack foods, pharmaceuticals, and more.

"I can't think of a flexible package that we can't put a zipper on," says Robert Hogan, director of sales and marketing at Zip-Pak in Manteno, IL, an Illinois Tool Works Company. He recalls that as early as the 1950s there were slider zipper cases for crayons and pencils. However, he points out that it wasn't until 1972 that Dow introduced the zip-lock bag for food storage. What's more, he says, the critical thing was that they taught people how to use these bags through their advertising.

Even though the food storage bags gained wide acceptance, it wasn't until 1986 that Sargento shredded cheese became the first consumer product offered in a reclosable pouch. Most shredded cheeses — and then deli meats — soon followed. "Today, research suggests that consumers prefer resealable packages." Hogan says. "Consumers are very savvy about what they like and don't like."

For example, Hogan says that consumer focus groups have reacted very positively to Zip-Pak TD SLIDER™ technology, which, as its name implies, uses a clip that moves back and forth to open and reclose a pouch. "One woman pointed out that �there is no excuse for her children and husband not closing this package,'" he says. "Overall, it's the ease of use that appeals to people."

Thomas Winter, product manager for Fresh-Lock Zipper of Alcoa Consumer Products and Presto Products Company in Appleton, WI, notes that resealable pouches offer a number of benefits for the consumer. "The product remains fresh and dry," he says. "They add value to whatever is inside."

"Resealability is a big thing to consumers," says Mary Liz Cahill, national accounts manager for Bosch Easy Snap in New Richmond, WI. "They appreciate the convenience. The older generation also values good resealability for storing items like cereal that come in sizes that take longer to use up. Consumers love the Easy Snap. You really do hear it snap closed."

Jo Anne Forman, president of Boyertown, PA's Sealstrip says, "Convenience builds brands by increasing the consumers' perceived value of the brand. It influences the buying decision when looking for a choice or change. Resealable packaging increases repeat sales by keeping the brand message with the product, to the end of the product.

"Consumers spend about three seconds to look for the product they want to buy," Forman continues. "If they last had a reclosable package, that carried the brand message to the end of the product, and they know what brand/package they want. They quickly recognize the package. It makes their shopping job easier."

Bringing the players together
Winter describes his company's customers as three different groups, an assessment that holds true for the other closure producers as well. They serve: 1) converters who buy the zippers and film and have the equipment to produce pre-made bags; 2) co-packers, who make the pouch but also add product; and 3) large companies that have their own packaging lines.

Zip-Pak's SLIDER has been around for food storage bags for over six years but like the early zip locks, it has taken time for sliders to make it into consumer packaged goods. Hogan says that although SLIDERs use the same technology as press-to-close zippers, the complexity is in adding the clip. That, of course, takes partners. At this spring's Interpack in Düsseldorf, the company's products were demonstrated in a number of vendor booths, such as Bischof + Klein, UVA Packaging, and Wolf Packaging.

Winter also points out that while closures are an integral part of the package, a number of components have to fall into place. "We sell the zipper," he says, "someone else supplies the film, another company makes the equipment, and the final partner makes the product. It all has to be integrated." Typically, when they are the customers, large companies will bring all of the players together. In that case, graphic designers often have early input. In any case, however, designers need to know where the zipper is going to be placed before they prepare graphics.

Hogan says that today's designers have so many options that it is almost confusing. "Start with the package style you would like," he explains. "That determines the film structure and manufacturing processes. There are always many potential solutions to use — different machine options or retrofits and different films. Try to do a road map and coordinate so that the design is equipment compatible."
 

Specialty zipper advances
Retort pouches that can take the heat are also some of the hottest items in consumer packaging today. Zip-Pak offers a High-Temp retortable zipper, a version of which has been recently approved in Japan for a resealable "nutraceutical" bag application. Hogan explains that the bag holds a liquid food for feeding patients through a feeding tube. "After the pouch is emptied, it's opened and then water is added to hydrate the patient as well," he says.

This retortable zipper is new and in use in Japanese hospitals now. "It's significant for us," Hogan continues. "We didn't intend this zipper for hospitals, but if we can provide a retort zipper that meets those stringent standards, then it certainly can be put on pet food or something for human consumption." With their Japanese partner Toyo Seikan, Zip-Pak debuted the nutraceutical bag application at the Packaging Strategies Global Pouch Fair 2005, in St. Petersburg, FL, this month.

Hogan also points out environmental benefits like reduced trash when a reclosable pouch is used as a #10 food service can replacement. For instance, he says that 10 or 12 #10 cans fill a trash can while retort pouches holding a similar amount of product are flattened and don't take up nearly the space.

Fresh-Lock also introduced a line of polypropylene zippers for retort applications at the end of last year. According to the company, this series of retort zippers was developed in conjunction with Pyramid Flexible Packaging in La Habra, CA. In promoting retort pouches with its resealable zippers, Fresh-Lock's website asserts that "Retort time is reduced 30% to 50%, resulting in better-tasting more nutritious food, and energy savings. Shipping costs are dramatically reduced with the new packaging. It is estimated that one truckload of empty pouches equals approximately 25 truckloads of cans containing the same amount of food. Freight savings alone on receipt of empty cans may equal up to 85%."

In addition to retort, another specialty item is a reclosable pouch that prevents package contents from slipping into the zipper mechanism and clogging the zipper tracks. Zip-Pak, for instance, has Powder Proof, a press-to-close zipper that is constructed to do just that. Hogan says that there is great interest for using this for powdered milk in Asia and Africa and that there is also growing interest in producing club store size packages for items like baking soda.
 

Fresh-Lock's Winter says that one area where technical challenges remain is that of freezer packages with reclosable zippers. "Choice of zippers is very important here," he says. "Size is an issue and it's important not to use too small a zipper. After exposure to the cold, the material can become stiffer and then doesn't function as well. This is an area of research." He notes that the zipper material should be "easy to crush," because if the zipper is too hard, it's difficult to make a tight seal and moisture will get into the bag. He cites Hudson-Sharp's Inno-Lok pre-zippered films and bags as an example of good freezer-ready technology.

Zipperless closures
Unlike closures from Zip-Pak and Fresh-Lock Zipper, Easy Snap and Sealstrip offer alternatives to zippers. Easy Snap is not a pre-made closure but rather a reclosable package style and system. According to the company, the reclosable package is produced inline and the system to do that can be incorporated with a new piece of equipment or retrofitted to "virtually any" vertical form fill seal machine, and the closure can be applied easily to nearly all packaging films. Easy Snap products include lay-flat bags or stand-up pouches called Easy Up as well as a new, cup pack called Easy Go that can be produced as a reclosable or for one-time use.

This year, Sealstrip introduced Peel&Seal, a dry edged pressure sensitive tape that is applied to the full length of the package. According to Forman, once consumers open the end seal of the package, they peel back the tape, roll down the package, and use the tape to tape down the rolled-down portion of the package. The graphic usage instructions are icons printed on the Peel&Seal tape and can be customized by the package designer. Forman also cites significant cost savings of about half the cost of a Top-Zip zipper and about 25% of the cost of an Inno-Lok zipper roll stock solution.

She says, "The advantage to consumers is that the reclose is part of the package, they don't have to go find a clip or be educated on how to use the package. It's what they already do. Another advantage is it makes a more compact package for storage of remaining product. An important consumer advantage of flexible packaging is the ability of the package to become smaller as the product is used, and thereby reduce the air inside the package. Many existing reclose features prevent the consumer from compacting the package size for storage and thus negate an important flexible packaging advantage."

Obviously, competition among these vendors is fierce. It's also clear from focus group reports that no matter which reclosable system a company ultimately chooses for its packaging, consumers value that feature and it enhances the brand and product. Conversely, a poorly manufactured closure that doesn't work can cost a company repeat sales. Zip-Pak's Hogan quotes one consumer as observing: "I don't expect every product to have a reclosable package, but I certainly would like to have that choice."

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