Food Engineering

Pump up the volume

January 8, 2005
Maintaining or improving product quality and food safety compounds the challenge for faster filling machines.

Color-coded infeed screws and infeed stars with knobs and handles instead of nuts and bolts allow one tool-less person to complete a changeover for filling different-sized containers in less than seven minutes. Source: FMC FoodTech.
Fillers are the quarterbacks of food plants, handing off product that has been processed and tucking it away for packaging. It's the point at which bottlenecks develop and fumbles occur, making it one of the most critical players in production.

Nowhere is the need for speed more critical and mistakes more costly and potentially dangerous. Value has been added to the product, and a problem with the filling equipment can detract from quality or compromise consumer safety.



Children like juice drinks filled in blow/fill/seal filling systems, and mothers appreciated the tamper-evident packages.
Small wonder, then, food manufacturers continue to push for improvements in this area.

Nowhere is this more apparent than in aseptic filling. Significant time and treasure has been invested to improve aseptic filler technology in recent years, particularly for low-acid products in plastic containers. Dean Foods' Morningstar dairy division spent $14 million on a Stork Food & Dairy Systems line for extended shelf life (ESL) products in 2001, then duplicated the investment on a second line that was validated for low-acid aseptic filling in January 2003. While that process was playing out in Mt. Crawford, VA, Tetra Pak was securing a letter of no objection from the FDA in November 2002 for its LFA-20 (linear filler aseptic) at Jasper Products in Joplin, MO.

Both Stork and Tetra Pak had similar systems up and running in other parts of the world. To satisfy the FDA, modifications were made to allow Morningstar to fill Folgers Jakada and Hershey's flavored milks in high density polyethylene (HDPE) bottles and Jasper to do likewise for Dr Pepper/Seven Up's Raging Cow milk drink and other copack jobs. The biggest concession was the use of in-line filling, an approach that satisfied regulators' objections to rotary filling of aseptic products but which limited fill times to about 300 bottles per minute.



Newer innovations are leaving Kool-Aid Burst and its precursor, Mondo juice drinks, behind.
Now there's a new kid on the aseptic filling block, and she goes round and round. Boston-based HP Hood is installing a rotary filler from Shibuya Kogyo Co. Ltd. at its Winchester, VA, ESL dairy. The 81-head unit is rated at 600 16-oz. bottles per minute and can handle both HDPE and PET containers ranging from 8 to 32 ounces. FDA blessings are being sought for the system, part of a $40 million expansion at the plant. The process authority is National Food Laboratories, which validated a similar filler at the Mott's Aspers, PA, juice plant.



Validation of Mott's high-acid process should facilitate the Hood filing, predicts Ken Saisho, president of Shibuya International, the company's Modesto, CA, division. "We brought our technology to this country with slight modifications to satisfy FDA's tastes and way of thinking," he says.



The company has a 10-year track record in Japan, where processors have filled 3.5 billion aseptic containers without incident. Including the two US and one China fillers, there are 23 Shibuya fillers currently operating, with a unit capable of filling 1,200 bottles per minute scheduled to come on line in Japan later this year.



Sterile corporate marriage

The mechanics of filling are Shibuya's forte. The firm has made filling and capping equipment since the 1930s, with aseptic fillers tracing to the 1980s. Those machines employed an "inter-plug system" that filled incoming bottles with a sterilizing agent and held them for up to 10 minutes. Filling speed was undesirably slow. In 1994 Shibuya struck a partnership with Dai Nippon Printing Co. Ltd., a Tokyo-based printing and packaging conglomerate. Dai Nippon designed the sterilization system for incoming bottles, which are sprayed with heated hydrogen peroxide, rinsed with sterile water and dried. Neck grippers convey the bottles through the system. The cleaning process was engineered to achieve a 6 log reduction in bacterial survival, above the FDA's 5 log standard.



Instead of filling trays on the fly, Multi-Fill’s distribution system holds multiple trays in place for more precise filling and less waste while maintaining production speeds. Source: Multi-Fill Inc.
Reflecting a design approach that is becoming common in sterile filling, the Shibuya unit is completely enclosed in what amounts to a clean room in miniature. "Because people cause contamination, everything has to run automatically in the machine's isolator," Saisho says. Glove ports provide access to the chamber for clearing jams and minor servicing. Servicing by an operator doesn't break sterility and maintains the Class 0 level of microbiological sterility. Filler chambers are 304 stainless steel, with 316 stainless for all contact points.

The system runs up to five days between CIP cycles, though "we don't know yet how long our sterility can be maintained," he says. "Our clients don't have product coming in more than five days a week," giving them ample time to run the eight-hour sanitation cycle before the start of the next week's production.

Closures are the key failure point in aseptic filling of plastic bottles. According to Saisho, the PLC-controlled capper senses and records the torque applied to each cap. If the force exerted by the servo-driven capper falls outside the specified range, the bottle is automatically rejected. "If something wrong happened (to the finished goods), we can track it down and determine what torque was applied and if there was any deviation," he says.

Technological overkill is a danger with fillers, and few systems illustrate that better than the Asep-Tech blow/ fill/seal (b/f/s) system from Weiler Engineering Inc. In 1991, the Elgin, IL, firm placed modified versions of a system designed for pharmaceutical packaging with Jel Sert Co., West Chicago, IL. To date, Jel Sert remains Weiler's only food and beverage client, and the company has all but abandoned this market "for the immediate future," according to Marketing Manager Charles H. Reed. "Food and beverage is a path we've been down several times in the past."

Jel Sert applied b/f/s technology to Mondo Fruit Squeezers, a children's juice drink that was designed as a "fun" alternative to the juice box, according to the firm. The one-piece semi-rigid plastic bottles have a winged closure that is twisted off. Convenience and recyclability are advantages, but the unique application for a mass-produced drink container and the high sanitary standards of the package were the primary appeals to company owner Chuck Wegner.

Unfortunately, speed is not one of Asep-Tech's virtues. Wegner ordered 22 b/f/s machines to meet expected demand. Although contemporary versions of the units can blow mold and fill packages at speeds of 41 to 125 units per minute, the Jel Sert machines took about 15 seconds to form and fill a bottle. Marketing, not production, was the driver in Jel Sert's b/f/s application, although the tamper-evident packaging and the plant's ability to meet pharmaceutical industry standards for sanitation have enabled Jel Sert to gain a foothold in copacking of nutritionally enhanced food products.

Mondo has all but disappeared from grocers' shelves, though the package lives on with Kool-Aid Burst from Kraft Foods. Unfortunately, other innovative packaging in the children's drink segment has chipped away at the product's unique positioning. In Zone Brands claims its Bellywashers juice drink, a novelty beverage that relies on facsimiles of Scooby Doo's head and other characters to drive sales, surpasses Kool-Aid Burst and other noncarbonated brands in sales at 7-Eleven stores.

"Value-added products like Pedialyte and isotonic beverages might justify a million-dollar packaging machine, but sugar-water doesn't," reflects Weiler's Reed. "For now, the neutraceuticals segment doesn't have the capital for this kind of filling."



Haste makes waste

Beverage manufacturers are not alone in seeking faster fill rates. Food processors also are cranking up line speeds, and that creates problems when depositing ingredients in a horizontal form/fill/seal system. The problem is particularly acute in the fast-growing segment of frozen individual servings.



Glove boxes provide access to the sealed enclosure of Shibuya Kogyo’s rotary filler at the HP Hood dairy plant in Winchester, VA. Process validation for aseptic low-acid products is being sought.
"When the fill rates were at 60 containers per minute, that was okay," says Byron Larson, an electrical engineer with Multi-Fill Inc., West Jordan, UT. "But the going rate is now 120, which means fillers are basically throwing food at the container and hoping it lands there."

Multi-Fill specializes in fillers that deposit cooked pasta, rice, meat, fruit and vegetables into trays moving down a line. Complex sensor systems detect the presence of trays and adjust fill rates to line speeds to deposit a few ounces to a few pounds of product. The trays never stop, and faster speeds increase the likelihood of spilled product or an unappealing presentation.

Multi-Fill's solution is a distribution system that serves as a staging area for product. Trays arrive in groups of four, six or some other configuration, pause under the unit and receive their portions before resuming movement down the line. Product is handled more gently, faster fill rates are achieved and fewer sensors are required on the line, simplifying the process.

The distribution system was introduced in Europe two years ago. The unit straddles the production line and is about a foot wide and a foot high. US manufacturers recently began testing the system.

"The American manufacturing mind is based on assembly lines that never stop, so it's going to take a little change to accept this principle," says Larson. "But once you see one of these units in operation, you say, ‘This is the way to go.'"

The same premium on speed applies to food whether it's bound for a retort or a freezer. FMC FoodTech is addressing the retort scenario on several fronts, from new piston-filler designs to easier-to-use changeover parts. "You have to have a modular concept for the parts that come into contact with the container," points out Jan Sundberg, applications engineer at FMC FoodTech's Madera, California design and manufacturing location. The payoff is manifested in "dynamic quick changeovers" for different sized containers that are accomplished in seven minutes by Lenzburg, Switzerland-based Hero foods. The company uses an 18-head XL Unifiller to fill glass jars of jams and other spreads in 11 different shapes and sizes, with multiple changeovers on each shift. Tool-less changeparts and color-coded infeed screws and stars help facilitate the process, says Sundberg.

Modularity is particularly important on multi-shot lines. "Ingredients are getting very expensive, and processors don't want to overfill portions to make sure they get a few pieces of meat in each can, for example," he says. Granular, piston and vacuum fillers might work in tandem to deliver greater precision in the filling process. "It's becoming more popular with ready-to-eat chunky meals," he adds.

Speed and precision mean nothing if sanitary standards can't be maintained. FMC FoodTech puts particular emphasis on Unifiller, which satisfies both 3A and Europe's EHEDG standards for its clean-in-place system. CIP eliminates the need for fill station disassembly. A critical design feature is the absence of seals, which enables the valve to be cleaned in place. FMC FoodTech uses a special alloy from Waukesha for a non-galling interface between metal-to-metal contact points. The Unifiller valve parts are manufactured to tight tolerances for extreme filling accuracies.

Just as conventional dairy fillers are giving way to faster, more sanitary machines, modern food fillers are raising the bar in terms of line speeds. Faster speeds bring new challenges, and filling technology is constantly changing to meet them. For more information:

Jan Sundberg, FMC Foodtech,
559-661-3129,
jan.sundberg@fmcti.com

Bill Allred, Multi-Fill Inc.,
801-541-2756,
sales@multi-fill.com

Ken Saisho, Shibuya Kogyo Ltd.,
209-529-6466,
ken-saisho@shibuya-int.com

Charles H. Reed, Weiler Engineering Inc.,
847-697-4900