Stand Up for Flexible Pouches

As we walk down the aisle of retail grocery stores, we are assaulted by the vast array of standup flexible pouches sprinkled among so many shelves. As we visit the backrooms of foodservice establishments, we are startled by the extensive presence of standup flexible pouches.

For a package structure that was developed more than 40 years ago as the legendary Doy Pak and largely ignored for more than half the time since then, standup flexible pouches are exerting a major impact in this millennium.

Evolution of Standup Pouches
Not even defined universally, the category of standup flexible pouches encompasses families of flexible material pouches that—with little or no assistance—stand erect on shelves in retail display or in consumer/foodservice kitchens/pantries. Usually, the structure is characterized by a flat bottom of some sort. The base may be a separate sheet affixed to a side wall, an extension of one or more of the vertical walls, or a scored forced squaring of corners. The presence of a bottom horizontal panel permits the structure to stand on its base.

In its original format, flexible material structures intended for standing were fabricated with gussets that folded (or were sealed to each other) to form a sort of semi-rigid base and sort of “flat” vertical sidewalls to closely resemble a paperboard folding carton, one of whose attributes was, of course, to stand erect on a shelf or table. M. Louis Doyen’s Doy Pak contribution to the advance in flexible packaging technology was to employ only two panels and attach the third or base panel to the bottom of the two side panels. Perhaps the patents, royalty costs, human/marketer/technologist reluctance to change, slow machine speed, or some combination of these resulted in the paucity of commercial acceptance until the mid-1990s.

One incredible driver during that 1990s period of great concern over excessive solid waste was the perception that flexible standup pouches represented a much-reduced solid-waste environmental insult. Thus, a host of household chemical and personal-care products appeared in standup flexible pouches. Consumer inputs and feedback were largely absent, so results such as failure to drain contents or the loss of the standup feature led to a loss of consumer loyalty, i.e., repeat sales essential to the success of any and every food and beverage product. The concept failed within months in the United States and Europe.

This pothole on the road to universal acceptance of standup flexible pouches hardly deterred the owners of the worldwide Capri Sun franchise from applying hot-fill and water-vapor/oxygen-barrier standup flexible pouch technologies for their packaged fruit-flavored beverage products. It competed vigorously with the then-emergent aseptic paperboard lamination cartons and plastic barrier cups.

During this period, dry soup mix packers and some bakery mix packers moved into split-bottom pouches, fabricated from single-sheet roll stock, which fell into a category of neither standup nor pillow—good enough for leaning in specially engineered shelf displays, but not alone and unaided.

And then, in what was a bold move of that period, just 15 years ago, several dry products packagers introduced new salty snack food products using preformed moisture-barrier pouches, which, of course, are much more expensive than fabrication from roll stock. Consumer acceptance of the new snacks in standup flexible packages plus the assertive actions by suppliers and potential suppliers were evidence enough for food packaging development technologists to consider/test the structures for other new products.

Even as doubts about machine speeds and net economics floated about, new products that previously would have been introduced in bag-in-box or flexible material–lined paperboard folding cartons slowly began to permeate the human and pet snack, cracker and cookie retail grocery shelves. Amid the rush to three-sided triangular standup flexible pouches came new surges in the preformed four-sided block types for cookies and for the revitalized packaged roasted coffee beans and roasted-and-ground coffee in vacuum-brick, high-oxygen-barrier packs. And in the spirit of marketing competition came the debuts of Capri Sun “clones” in hot-fill “flat-top” and transparent plastic-barrier-lamination back panel standup flexible pouches, leading to major increases in the category.

The introduction of easy-open and zipper and slide reclosures for flexible pouches and for standup flexible pouches fueled further applications for bakery and snack products. Surprising to some outside observers, some traditional products such as sandwich cookies (e.g., Oreo) were dimensionally altered to fit the new package format. Obviously, no brand owner changes a flagship product without careful consumer testing, so we must assume that the product target market was a slightly different niche (and mouth size) than the traditional. Whether the standup flexible pouch drove the new products or the new products drove the use of the standup flexible pouch, the other element was integral to the current successes.

This was followed, almost of course, by candies—first prewrapped to protect against scuffing and breaking, and later without prewrapping—providing ease of access, i.e., convenience. We ponder why so much time elapsed between the development of standup flexible pouches, the application of reclosure features, and the marriage of the two for packaging fun foods such as candies, snacks, and cookies.

Could a product group generically called “trail mix” have grown to its present proportions without the dual thrust of standup (water-vapor barrier) flexible packages, designed for pocket portability plus zipper reclosure for convenience in use? And then came dried fruits—raisins and cranberries—possibly because the marketers were sparked by the relationship of individual trail mix components with the potential for containing and distributing the traditional and new dried fruit in “innovative” packages. The competition was joined between paperboard cartons—with no inner liner—convolute wound paperboard canisters, and standup flexible pouches. Consumers are now offered a range of different package options to gain access to their controlled-water-activity snack, package sizes ranging from single-serving to giant.

And then came the 2000 invasion into frozen foods: French-fried potatoes in sidewall-gusseted standup pouches. The packaging concept has been extended into the world of stir fry and other convenience ready meals, led by that other standup flexible pouch pioneer, Printpack.

Substituting Packages
Although this recitation appears to credit new-product shelf differentiation as the current driving force for standup flexible pouches, the fact is that much of the volume has been and is being derived from package structure substitution. The venerable and reliable film-lined paperboard folding carton, dating back to nearly World War I, is facing yet more substitution crises. Long regarded as less than consumer-friendly and costly (although, despite its multiplicity of layers, it is one of the least expensive of package structures to achieve reasonable moisture barrier), paperboard folding cartons were assaulted by pillow pouches. These conventional flexible constructions invaded and captured applications such as a few dry breakfast cereals, salty snacks (yes, Virginia, potato chips packaging started as bag-in-box!), candies, etc. While some consumers loudly complained about opening paperboard folding cartons and their associated inner plastic-film liners and the absence of any reclosure, most continued to purchase cake mixes, breakfast cereals, and hard bakery goods in the structures, some of which still use waxed-paper liners. How could kids read and learn at the breakfast table except from the backs of cereal cartons, and their moms read recipes, went the rationales.

But, reasoned the standup flexible packaging converters and equipment makers, standup flexible pouches were a better substitute for bag-in-box. So these categories were targeted, with some interesting responses. Breakfast cereal packagers all tested the structures, with dazzling positive results from packaging and marketing managers and trade publications. But, regardless of consumer complaints, the ever-threatening replacement of the lined paperboard folding carton has not yet occurred.

But the declining cake and cookie mix category was another market: some major regional brands had long ago shifted to flexible laminations with standup features. The national brands were forced to differentiate themselves—with packaging, of course. And so has begun a gradual shift from the “traditional” structures to flexible lamination structures that stand up by themselves on store, kitchen, and foodservice bakers’ or sprinklers’ tables. No one can quantify the effect of the standup flexible pouch on the sales of baking mixes, but in foodservice, hardly a lined paperboard carton of baking mix is to be seen.

The tales of lined paperboard folding cartons for hard bakery goods have been handed down from generation to generation. Some regions demand flexible pouches. Some quality levels dictate standup rectangular solids (e.g., Pepperidge Farm cookies and Goldfish). Although the old standbys such as basic Ritz Crackers and Cheez-Its remain in lined paperboard folding cartons, their newer offspring are in one or another version of standup flexible pouches, with easy-open and reclosure features. Does this standup flexible packaging fall into the classification of substitution or new product packaging?

Slowly the bastions of paperboard folding cartons with their interior heat-sealed coextruded polyolefin film liners are receding before the inexorable flow of flexible packaging. The single-“ply” pouches appeared to function as reasonable substitutes for printed paperboard cartons in protecting the physical integrity of contents, as well as protecting against the entry of atmospheric moisture that would disrupt the textural properties and ultimately the biochemical quality. Because of their unitary construction, standup flexible pouches generally have better barrier characteristics than interior liners. Additionally, because most standup pouches incorporate much more polyethylene, which provides stiffness and heat sealability as a bonus, it imparts moisture barrier.

Somewhere over the horizon looms the new threat of cubical polyester jars—and thermoformed and injection- and blow-molded plastic canisters and cups—for dashboard dining. Thus, reclosable standup flexible pouches, although bearing the advantages of portability and convenience, are as vulnerable to replacement as were their predecessors. In food packaging, no package construction is ever so sound that it cannot become a target opportunity for a new material, structure, or system.

Retort and Hot-Fill Pouches
This thesis of vulnerability may be no better exemplified than by the incipient penetration of retort pouches into the two-century reign of two- and three-piece metal cans. Regarded for the past 50 years as requiring minimal heat-seal perimeter to minimize probability of heat-seal failure issues, the 21st-century versions of retort pouches are mostly standup. Erect appearance facilitates retail display, so essential to acquaint consumers visually with this “new” concept—which, as all food scientists and technologists recall, was first developed during the 1940s, commercialized during the 1960s, and since used as mainstay military and emergency rations.

The return of retort pouches of low-acid foods to the forefront of North American food marked yet another milestone in the saga of standup pouches. Like the split-bottom pouches of dry soup/sauce mixes, these structures were intended not to be standup-alone pouches, but rather to stand/lean in paperboard secondary cartons for shelf display. Although the added heat seals on the retort pouches represented an increased hazard in the most difficult realm of seal integrity, the standup feature avoided the lay-flat of pillow pouches and fostered visible shelf display for what was until then effectively an unknown packaged-product category. Today, no food trade periodical is complete without reference to the rebirth of the retort pouch, even if the sources for most of the fish and the pouches are offshore. The success of standup retort pouches for pet foods, solid-pack fish, and now chicken-and-rice products suggest that these and related categories will experience major growth on their current narrow base. To accommodate to the interest in retort pouches, Presto (Alcoa) has developed a line of retortable zipper closures that have received regulatory acceptance in the U.S.

Allied to retort pouches engineered for low-acid solid foods are standup flexible pouches for hot-filled high-acid fluid foods, begun way back by the Capri Sun fruit-flavored beverages but now reaching far beyond in product and package structure. The addition of a dispenser to the pouch offers a product-access convenience that reaches far beyond the “traditional” straw that must puncture the side wall.

Incorporating an appropriate injection-molded polyolefin device represented a major heat-sealing challenge for converters and packagers. For years, Japan’s Hosakawa’s CheerPack, featuring a center-affixed reclosable filling/dispensing closure, was the major structure among a host of alternatives. Recently, Kapak, a long-time leader in standup pouch technology, introduced QuadPAK®, a side-gusseted flexible polyester/aluminum foil/nylon/polyethylene standup pouch featuring a Seaquist Smart Spout® resealable closure. The closure contains a silicone valve that permits inverting with no spillage until the side wall is stressed. Technology for applying the closure and filling through the nozzle at up to 250 packages/min came from Germany’s Hensen, the company that developed the original Capri Sun packaging technology. The use of side gussets increases the flexible material surface area and the internal volume, thus offering greater display area. Initial commercial application appears to be for an isotonic beverage, Hygrade® sports drink, which was originally packaged in the CheerPack.

To try to maintain its leadership position in standup pouch technology, Kapak also has introduced FlexiBowl, a single-serve, fill/seal, and eat-from bowl for dry granular foods. The base is engineered to permit the consumer to stretch it to a large-diameter opening after removing the entire top, which features a laser cut for easy stripping.

Next-Generation Packaging
When, back in the 1960s, first we witnessed the DoyPak, we were impressed: here was a flexible construction that could overcome the one deficiency we perceived in pillow pouches—the inability to stand erect on a shelf. That the functional benefit was not immediately seized by technologists and marketers to for the advantage of their products was an amazement.

During the 1970s and ’80s golden era of packaging innovation, the growth of flexible packaging was being retarded by some arbitrary obstacles. Not until the artificial spark from environmentalists who perceived the polyester/polyethyene lamination substituting for plastic bottles as somehow less damaging to the land and water did the standup flexible pouch reemerge from its place in the historic archives. Even as marketers sought unique means to reach consumers and as Capri Sun captured market just before the advent of aseptic packaging into bricks and blocks, the participants apparently could not envision the merits—obvious in retrospect—of standup flexible pouches. Even the first steps into the package for salty snacks were hesitant, as if the observers feared for some consumer rejection if they moved too rapidly.

But as the courageous converters offered and re-offered the structures, it required some real daring by packagers to enter a world in which the line speeds did not match the mainstream, the costs were higher than for the old lined paperboard folding carton, and the stock clerks did not exactly comprehend the placement of the pouches on the shelves. But the consumers understood—as new products appeared, consumers compromised their expectations. Pouches were not required to stand erect as if on parade: they could lean a bit and still function. And the bold move to incorporate easy-open and reclosure zippers did not just complement the concept: it became integral to launch standup flexible pouches to a rightful position near the head of food and even beverage flexible packaging.

Now, as standup flexible pouches venture into the technically much more complex arenas of retort pouches—and perhaps into aseptic—the question is not how far can standup pouches reach, but rather—for us who are immersed in change—how soon will it be before the next-generation innovation intrudes? In this coming cycle, having been inured by the experience, technologists and marketers will not be nearly as reluctant to try as they were during the early years of standup flexible pouches. Meanwhile, however, stand up for the spreading invasion of standup flexible pouches.

by AARON L. BRODY
Contributing Editor
President and CEO,
Packaging/Brody, Inc., Duluth, Ga.
[email protected]