Reclosable zippers with slider-format designs are leading the way to new and revamped plastic packaging applications.
Sliders have existed for several decades, but in recent years the market has experienced greater volumes, improved technology and narrower profit margins.
Generally, slider-format demand is growing faster than demand for the higher-volume, conventional press-to-close zippers. Manufacturers including Pliant Corp., Pactiv Corp., Illinois Tool Works Inc. and Presto Products Co. are competing to lower sliders' price per running foot.
When the first widely advertised slider bag hit the market in 1995, some observers thought consumers would reject it as too costly, recalls industry veteran Bob Stolmeier of Shelbyville, Ind.
But the bag proved successful, said Stolmeier, who sold his business in October 1999 to Pliant's predecessor and remains a consultant to the Schaumburg, Ill.-based firm. Pliant makes reclosable bags, pouches and films among its commercial, industrial and personal-care flexible packaging lines.
``Customers buy value, not price,'' Stolmeier said. Consumption continues to grow ``as long as zippers and sliders continue to bring value to the consumer.''
Consumers prefer the slider package for commodities such as cereal, sugar and macaroni, Stolmeier said. ``Some day a consumer is going to walk into a store and buy a bag of corn flakes.''
Stolmeier also is president of joint venture Alliant, which Pliant and Supreme Plastics Ltd. of London formed in mid-2001 to make press-to-close zippers for the North American market.
Slider bags have benefited from customer efforts to find innovative ways to differentiate their products, said Gary Rehwinkel, director of technology and manufacturing for Pactiv's Hefty Slide-Rite advanced closure business in Canandaigua, N.Y.
``If you have an upscale closure like a slider, you also may be looking for an upscale feature like a side-gussetted [bag], or a visual feature that is readily apparent to the consumer [and] may be just beyond the closure,'' Rehwinkel said.
One recent example includes a baby wet-wipes package that Kimberly-Clark Corp. of Dallas started selling in Europe in December. The Pactiv-created package features an internal baffle. A year earlier, Pactiv began producing a slider bag for the shredded cheese line of Sargento Foods Inc. of Plymouth, Wis. The Institute of Packaging Professionals' 2001 AmeriStar competition recognized the application.
ITW's Minigrip/Zip-Pak division has invested significantly in a slider initiative over several years as a complement to its major press-to-close presence.
``We went commercial last year with a preformed pouch'' with a slider and have installed a half-dozen systems for converters' use, said Robert Hogan, director of sales and marketing for the Zip-Pak business in Manteno, Ill.
In late 2001, Kraft Foods Inc. of Northfield, Ill., began test marketing an ITW slider-equipped package for shredded cheese. Another ITW slider in development involves a vacuum package for sliced meat.
``Customers want additional features,'' often to extend a product line, Hogan said.
ITW develops ways to make preformed pouches and, by request, can place a slider on an existing packaging line.
``The slider is great, but not everyone is willing to give up conventional zippers,'' Hogan said.
In an unusual application, ITW supplies press-to-close zippers for a biodegradable pouch that a sportsman can use for urination during an outdoor hunting excursion. Rolling I Innovations of High Hill, Mo., markets the camouflage-print Spare Bladder with integrated handles. Inside the reclosable, 24-ounce pouch, an absorbent transforms the waste into a gel.
Some companies have complained about male-female flanges in zipper pouches getting clogged. To solve that problem, ITW has developed a large-format, reclosable bag with holes behind the female profile to return loose flour or powder into a package, Hogan said. ITW is based in Glenview, Ill.
Presto has provided sliders to private-label converters for about five years and has noted some movement away from press-to-close, said Richard Custer, unit manager for Presto's Fresh-Lock Zipper business in Appleton, Wis. The unit sells raw zipper stock to product packagers.
In the slider niche, ``everyone in the business, us included, is working hard to carve a position in the technology,'' Custer said. ``Some items in the lawn and garden area have made the move'' to sliders, and the matching of a stand-up pouch with a slider is becoming more popular.
Presto, a subsidiary within Alcoa Inc. consumer products, also makes bags, mostly for storage rather than food packaging.
Meanwhile, Innoflex Inc. of Alpharetta, Ga., has spiced up the press-to-close market with its Inno-Lock technology. Film suppliers or converters use Innoflex equipment to pre-apply reclosable fasteners to roll stock.
``Transverse-applied zippers on machines with applicator devices have done well, [but] pre-zipper roll stock has done better,'' said Jack Hogan, vice president and general manager with Innoflex, a technology company.
Inno-Lok units entered the market in 1997. Now, 16 machines operate in domestic plants, four in Europe and one each in Israel and New Zealand.
Contract manufacturers Valley Packaging Supply Co. in Green Bay, Wis.; Technipac, Inc. in LeSueur, Minn.; and Polymer Packaging Inc. in North Canton, Ohio, are among those operating multiple Inno-Lok machines.
``Every one of the domestic converters taking one of these machines have taken a second machine within six to eight months,'' Hogan said. ``These things can place a zipper north, south, east or west within one-sixteenth of an inch at a speed of 100-110 cycles a minute,'' Hogan said. ``Our pre-zippered roll stock can let you enter the market in less than four weeks.''
For basic formats, a machine with a 30-inch application range costs $400,000-$425,000, and one with a 54-inch range costs $525,000-$550,000.
Exclusive Inno-Lok machine maker Hudson-Sharp Machinery Co. of Green Bay customizes each machine and can deliver a unit in about 12 weeks, said Peter Hatchell, Hudson-Sharp president.
Attachment maker Park Air Corp. of Brockton, Mass., feels customer urgency.
``I am pushed to unwind faster, seal quicker and do it with multiple lines,'' said Jerry Goldman, Park Air president and chief executive officer.
Park Air is completing development of an add-on turnkey system with a zipper applicator, ultrasonic crimping sealer, a gripper-slider applicator and a vibrator feeder. Projected cost is around $120,000, Goldman said.
In general, reclosables and plastics are ``replacing all sorts of containers,'' and fitments are involved, said Lance Czachor, vice president of converter Valley Packaging.
Intellectual property, particularly involving multiple slider-related technologies, creates a highly contentious undercurrent within the industry.
``The giants are going at it,'' one observer said. ``It could be legal gridlock if everybody took everybody to task.''
A session on the latest trends in reclosable technology is planned during the Film & Bag Federation conference April 28-30 in St. Petersburg Beach, Fla. The federation is a business unit of the Washington-based Society of the Plastics Industry Inc.
