The snack packaging challenge
Feb. 12, 2013
by Charlotte Atchley
Snack foods present specific challenges to the packaging process. Snacks tend to be fragile with a light density, and on top of those two hurdles, snacks often are terribly irregular. Their inherent fragility and odd shapes make potato chips, tortilla chips and other snacks difficult to package quickly without damage.
Vertical form/fill/seal (f/f/s) systems and pillow pouch packaging have answered this challenge. The air-filled pillow pouch provides protection for the fragile product, and the vertical nature helps speed the process along.
Spicing up bag styles
Most snack manufacturers package their products in weights ranging from ½ oz to 1 lb or more, and they don’t want to waste floor space or money on packaging machines dedicated to each size and bag style. According to Mark Lozano, sales manager for TNA North America, Coppell, TX, versatility is the No. 1 priority for snack producers looking at vertical packaging equipment.
“To address versatility, a machine has to be able to do traditional American bags, which are the larger bags, while still being able to do the smaller bags,” he said.
Meeting the needs of different customers and consumers goes beyond bag sizes and also into bag style. Snack producers are looking for bags to fit product variations in regional preference, serving sizes and dietary needs, according to Tom Egan, vice-president of industry service, PMMI. As snack producers also look for ways to stand out from the competition on supermarket shelves, moving away from traditional pillow pouches is a way to do that.
“Flexible packaging formats with the ability to produce four-sided bags, block-bottom bags and different sizes of pillow bags on the same machine are very important because they improve production flexibility and reduce costs for equipment and floor space,” said Jeff Almond, snack food industry manager for packaging systems, Heat and Control, Inc., Hayward, CA. Having vertical packaging systems that build multiple sizes and styles is a snack producer’s packaging dream. Heat and Control’s Ishida Atlas Flex bagmaker produces a variety of formats, including four-sided hem seal, block-bottom and pillow pouch bags.
Add-on equipment can save snack producers money by enabling existing equipment to handle new bag styles and sizes. Heat and Control offers upgrade kits to retrofit machines to produce gusseted, block-bottom and four-sided hem seal bags. The vertical f/f/s can also convert back to pillow pouches efficiently.
Kliklok-Woodman, Decatur, GA, also designed its machines to handle a variety of packaging styles including a new way to package multipacks of product, opening new marketing doors for snack companies. Small snack bags have often been confined to end-of-aisle, convenience stores and vending machines. Multipacks of smaller snack bags can open additional channels for snack producers to get these products into consumers’ hands. Packaging multi-packs, however, creates challenges with using excessive packaging material and streamlining the system with the rest of the packaging line. Kliklok-Woodman developed its Woodman Vantage Multi-Bag Baler to offer solutions to these issues.
“Snack producers are looking for ways to differentiate themselves on the grocery shelf as well as get a large single ring up at the register for small bags,” said Ross Long, vice-president of marketing and sales, Kliklok-Woodman. “They have been looking for ways to bring a different presentation of their small bags into the marketplace.” This multi-pack equipment wraps traditional single-serve or 100-Calorie snack bags into a tight single pack with greater pack density. This increased density makes snack bales easier to store, stack and transport. According to the company, it also uses less material than other multipack formats.
The baler is produced in a vertical f/f/s format so it easily adds onto a snack producer’s existing bagger.
Speeding up packaging
Saving space while offering bag flexibility may be a top priority for most snack companies, but speed is always right behind it on the list of things needed from packaging equipment. Varying bag sizes on the same equipment, however, can limit the speeds at which baggers operate. Large 1-lb bags have to be run at a slower speed than smaller bags. Finding ways to run larger bags faster brings the whole operation up to speed.
“As you look at infrastructure in existing plants, real estate is limited, and we’re set up to run large formats at rather moderate speeds. What TNA has done recently is a pretty significant development where we can run the large bags at higher than moderate speeds,” Mr. Lozano said.
The company’s equipment can run packs of traditional single-serve potato chips at speeds of up to 130 bags per minute (bpm), while 1-lb family bags can run at 60-70 bpm. Before, the machines could only reach speeds of 45-50 bpm. Extruded products can be bagged at 170 bpm. “In the same footprint that you were usually locked into speeds of 80-100 bpm, we can increase that with the same floor space used,” Mr. Lozano noted.
TNA reached such speeds by improving the geometry of the product flow between the scale and the bagger. The company also improved the chutes between the scale that weighs snacks to incorporate and control the natural parabolic flow. “If you control that and cut out all the swirling and bouncing the product does, that’s how you gain your speed and control product flow,” Mr. Lozano said.
Continuous motion instead of intermittent motion also helps baggers reach higher speeds. “Continuous motion allows us to feed film or advance the packaging material at the same time that we’re sealing the material,” Mr. Long said. The company can upgrade an existing intermittent motion machine to continuous motion, so snack producers can increase their packaging systems’ speeds without the added costs of a new vertical f/f/s machine. Heat and Control’s Atlas 233 and Atlas 223 vertical baggers use continuous motion to reach speeds of 80-120 bpm and 200 bpm, respectively.
According to Mr. Long, however, there is such thing as too fast in vertical packaging. Because of the irregularity of snack packaging, problems can occur when trying to bag snacks too quickly. Once product variability comes into play, at high speeds, the time to adjust to variability diminishes.
“If you time the machine to run very well on a potato chip with a 2-in. average diameter, and suddenly the potatoes coming through the fryer are 3 in. in diameter, you’re going to increase your packaging waste unless you slow it down,” Mr. Long said. Keeping these real-world production challenges in mind, Kliklok-Woodman pursues speeds of 90-110 bpm.
A major hurdle in vertical f/f/s machines is the human intervention necessary to run these systems. Operators must oversee changeovers of films for different products, which open the door to mistakes. To eliminate human error and further automate the packaging process, TNA introduced a bar-code-reading system on its equipment that matches the product being bagged with the UPC of the correct packaging film. Before, matching the product with the right packaging was up to an operator.
“If someone put a film that said there were no peanuts or no dairy in a bag and they ended up putting sour cream and onion or some type of peanut product in that bag, it could wind up in the marketplace and someone could get hurt,” Mr. Lozano said. “It can’t happen when you’re running the UPC code; it’s not going to happen. The machine will not run the wrong film with the right recipe.” The machine continuously verifies the packaging and recipe match.
A sensing system on TNA’s equipment detects failed seals and rejects those bags immediately. If several bags get tagged as rejects, the system alerts the operator. By further automating the process, the company reduces waste and also streamlines the rejection process.
The new technologies in vertical f/f/s save resources, time and labor and improve versatility, speed and automation, which is every snack producer’s end goal.