Professor Mounir Laroussi is at work in the Applied Plasma Technology Lab at Old Dominion University. His development of an atmospheric plasma generator could pave the way to a low-cost alternative to chemical sterilization of packaging materials. Source: Chuck Thomas/Old Dominion University.
Ten Delta arms place disposable coffee pods into defined cavities on a belt. The machine’s compact design is standard, but the number of arms varies depending on the packager’s throughput needs. Source: Bosch Packaging Technology.
For decades, hydrogen peroxide was the only FDA-accepted treatment available to food manufacturers, with peracetic acid becoming an option in recent years. Both chemicals require rinsing and drying, and supplying the energy and treating the water can be a significant cost, particularly for high-volume producers. Two years ago, KHS USA Inc. and aseptic copacker Gehl Foods, both in the Milwaukee area, announced a dry sterilization process using hydrogen peroxide gas had passed muster with FDA regulations after validation tests with a high-speed filler at Gehl’s dairy plant. Unfortunately, the successful validation was the end of the story: The equipment was removed after the trial and was not used by Gehl to produce finished goods.
“It’s always difficult to put together the protocols and the right disciplinary skills to win FDA acceptance,” observes Larry Keener, a microbiologist and long-time process authority. Experts in physics, process engineering, toxicology and microbiology are needed to usher novel sterilization systems such as gas and atmospheric plasma through FDA review. “It’s a fool’s errand to try to do it alone,” Keener says, adding more than one microbiologist should be involved “because of all the considerations.”
Given the time, money and commitment needed, a generator of atmospheric plasma for sterilization is at least five years off. But considerable work already has been done to demonstrate the germicidal effects of this novel technology. In May, a patent for a plasma generator, or “plasma pencil,” was issued to Mounir Laroussi, a professor in the electrical and computer engineering department of Old Dominion University and a pioneer in the generation and use of plasma, often referred to as the fourth state of matter. Considerable R&D is underway now in the Netherlands on the use of atmospheric plasma, but Professor Laroussi’s work predates it.
Plasma refers to gaseous molecules that have been excited to form radicals, typically in a vacuum. A fluorescent light is an example of plasma technology. Creating plasma under atmospheric pressure is more challenging, and Laroussi’s team envisions a pencil-like device that would emit a beam of ionized gas that would kill microbes but be cold to the touch and draw little power. From a package sterilization standpoint, it would leave no residue, eliminating the need for a pre-filling rinse.
“My work has been focused on biomedical applications in the last few years, mainly using the plasma pencil,” says Dr. Laroussi, who also serves as director of the Laser & Plasma Engineering Institute at the Norfolk, VA university. “We are having quite a bit of success in these applications.” His device takes in helium, oxygen, argon, nitrogen and air and converts them into a plasma plume that is discharged into open air.
While cold plasma could be applied directly to food, the approval process would be complicated by scrutiny from food additives authorities, points out Keener, who heads the Seattle, WA firm International Product Safety Consultants. “But for treating hard, inert surfaces like packaging materials, the concern about the chemistry would be diminished,” he says. “Given that there would be no residues, it would be easier to get across the line.” Plasma also would relieve food companies of the burden of storing and handling a 35 percent hydrogen peroxide solution.
A technician places an electron emitter into a machine designed to sterilize caps and other beverage closures. The low-power emitter is safe to use in industrial spaces, though it is only effective for surface sterilization of packaging materials. Source: Advanced Electron Beam Inc.
Sustainable aseptic
A technology closer to tackling the packaging-regulation minefield is low-power electron beam. E-beam emitters already are used to sterilize caps and closures for hot-fill containers, lowering sterilization costs by 70 percent. A dairy cooperative in the UK is using e-beam to sterilize film for packaging single-serve coffee creamers in aseptic packs. Based on the UK reception, the company is considering FDA review for US export or production.Farmright Group Ltd., a vertically integrated dairy company based in Bristol, UK, created Dairystix tear-and-pour portion packs of half and half, whole milk and other milk products. The package provides 28 days shelf life, 173 days if the milk is UHT processed. The group incorporated a low-power electron generator from Advanced Electron Beam Inc. (AEB) to sterilize Dairystix’s film prior to filling. Taking chemicals, steam and rinse water out of the sterilization process boosts Dairystix’s green profile, an image Farmright wants to nurture.
Unlike systems used to pasteurize or sterilize food, low-power e-beam emitters are compact units that easily fit inside a cabinet. Low power means limited radiation, but it also means limited penetration. Surface treatment of closures and film can be done, but preformed PET or HDPE containers pose a challenge. Shiboya introduced a bottle sterilization system for high-acid foods to the Japanese market last year, and AEB, working with an equipment manufacturer, hopes to introduce its bottle probe this year. Included among AEB’s OEM partners: KHS.
The technology has been validated for pharmaceutical applications, according to Josh Epstein, AEB’s marketing director, and FDA letters of no objection are being sought for several food package uses, but to date, no reviews have been completed. About 150 emitters are in use worldwide, mostly in food applications, he adds.
“The growth area is aseptic,” says Epstein, “and the real story in aseptic has been in PET and HDPE bottles.” Besides eliminating chemical residues, “one of the biggest benefits is removing the heat [for drying] from the process,” he says.
Tetra Pak received a letter of no objection in 2006 for material sterilization using a combination of hydrogen peroxide and UV light. Incorporated in high-speed filling machines that produce up to 400 packages a minute, the system fulfills “packaging material sterilization requirements without increasing the size of the chemical sterilization bath or the amount of chemical sterilant,” according to Tetra Pak’s Brian Thane, director of aseptic technology.
Interest in alternatives to chemical sterilization is high, allows Rafal Knap, a process authority with Dublin, CA-based IEH, but he doubts FDA clearance for new technology will occur for at least a few years. “It’s a substantial investment to file and get approval,” he says. “It boils down to money and finding a food company willing to be first.”
Multiple sizes of cans and bottles in multiple configurations are accurately positioned and wrapped on corrugated trays and pads with Thiele Technologies’ continuous motion tray former. Simplified programming and end-user requirements prompted the switch from a mechanical machine. Source: Rockwell Automation.
The waiting game
The lag between the introduction of new technology and its use is sometimes measured in decades. Direct drive technology is an example: Putting a motor on a shaft eliminates the need for a gearbox and reduces the amount of power needed to drive the shaft, but direct drive is only slowly penetrating the food manufacturing environment, with most deployments involving new lines. Gearboxes have become part of “the hidden waste on your equipment,” suggest Andy Hansbrough, a packaging industry specialist with Radford, VA-based Kollmorgen, a provider of motion systems and components for machine builders. Until direct drive is widely embraced, the waste will continue.Single drive and control is another example. “We wanted motion controls and PLCs in the same box in the 1990s,” remembers Bob Estes, a 28-year veteran of food manufacturing who now serves as discipline manager for instrumentation and controls at Middough Inc., Oak Brook, IL. It would provide a simpler, less expensive controls solution, “but whether it works and can be maintained depends on people understanding the programming,” says Estes. Both Rockwell Automation and Indramat, now Bosch Rexroth, developed the desired technology, but it only gained traction when end-users demanded machines to meet higher throughput requirements.
The Nigrelli division of Thiele Technologies Inc. was building tray former packers with mechanical line shafts until two years ago, when it was commissioned to build a machine that could handle up to 3,600 bottles and cans of beer a minute for a major brewery. Servo drives and motors would be required, and without integrated motion and logic control, double the amount of programming would be required. Instead, the machine builder switched to integrated motion control from Allen-Bradley for the high-speed machine, which leverages a SERCOS interface to meet required data transfer speeds.
Building the machine a decade ago would have been possible, “but it wouldn’t have been as user friendly on the controls side,” explains Jason Jensen, a controls engineer with Thiele Technologies. “Instead of writing two codes, I’m writing the instructions for the servos right in the PLC code.” The machine, which is much smaller and has fewer components than its predecessor, delivers the kind of versatility, easy changeover and high throughputs packers are demanding.
Simplicity has been the goal of Rockwell’s integrated controls since the technology was introduced a dozen years ago, according to Leo Petrokonis, business development manager for packaging. Safety control was added to sequential and motion control a couple years ago. “The safety network and the safety controls aren’t big yet in packaging, but people are going to want a machine that can be down in one area while other tasks are functioning,” Petrokonis predicts.
While Thiele’s machine highlights the dramatic improvements occurring in controls technology-Rockwell stopped using the term PLC in recent years and began referring to PAC (programmable automation controller)-it also underscores growing dependence on OEMs and automation suppliers. “If the maintenance man can’t fix it, you have a problem,” says Middough’s Estes.
Multi-tasking machines
Function blocks are gradually replacing long lines of computer code and simplifying machine programming, and efforts to establish industry standards such as PackML standard machine language should simplify the task of line integration. But much work remains, and manufacturers’ focus on OEE is placing a greater premium on machine data reported in a consistent manner.“With staff engineering downsized, a lot of our customers want us to assume the risk and bear responsibility for making sure all the machines on a big line are coordinated and run smoothly,” says Jon Otto, product marketing manager for Bosch Packaging Technology, New Richmond, WI. The company has seen a marked increase in integration assignments in the last five years.
The demand for a single point of accountability is being felt at all levels of the services spectrum, from machine builders to architectural engineers. Tim Kent, research & marketing director at Louisville’s Raque Food Systems, says the firm increasingly is involved in the installation and setup of equipment upstream and downstream from its piston fillers, in part to ensure the filler isn’t starved or delayed by timing issues involving other OEMs’ equipment.
The Jacksonville, FL design/build firm Haskell Co. recently acquired E2M, an Atlanta integration specialist, because “customers began asking us to become involved beyond the building to help them with line relocations and line startups,” reports Jean-Paul Saenz, leader of Haskell’s food & beverage division. E2M’s development of advanced simulation tools based on gaming software dovetailed with Haskell’s desire to help food companies achieve greater flexibility. “It’s just a natural fit for us,” says Saenz.
Multi-function machines that sidestep the integration issue entirely are cropping up more frequently in packaging departments. Cartoners measuring 35 ft. or longer collate, pack, code and glue finished cartons and, in some cases, eliminate the need for box formers and other support equipment. Newer technology such as compact servos directly coupled to end effectors is enabling the trend, replacing pneumatic devices and other old technology.
“The market wasn’t demanding a motor with a drive on it,” Mike Grinager, vice president-technology at Brenton LLC, Alexandria, MN, “they were looking for space to place multiple cabinets.” By shifting to newer components, Brenton was able to shrink its wraparound casepacker to about 26 ft. from 40 ft. in length.
Not everyone thinks the trend is altogether positive. For some, it reflects lean manufacturing run amuck. Lean principles argue against accumulators and conveyors, but “if you don’t have accumulation between zones, if one area goes down, the whole system is down,” argues John Gunst, packaging design manager at POWER Engineers, Boise, ID. Regardless of how well the unit runs, flexibility is lost, both in the range of packages handled and the ability to insert new machinery down the road.
Many of the latest innovations in machine design will be on display in November at PACK EXPO in Chicago, though not all of it will be overtly visible. For example, Axon LLC, Raleigh, NC will debut a redesigned mandrel sleever, part of its Aurora series, according to General Manager Brad Wegner. The most significant change is the use of PackML. It’s one of several PackML rollouts planned, as standards proponents try to win market acceptance of the concept.
“Developments in industrial standards come in dog years,” says John Kowal, market development manager of B&R Industrial Automation and a long-time advocate of packaging equipment standardization. “It takes seven years to do what happens in a year in consumer electronics.” But proponents believe standardization will provide a platform for greater innovation, and that’s a good thing.
For more information:
Josh Epstein, Advanced Electron Beams, 978-658-8600, jepstein@aeb.com
Brad Wegner, Axon LLC, 919-772-565
Jon Otto, Bosch Packaging Technology, 715-246-6511
John Kowal, B&R Automation, 630-258-0371, john.kowal@br-automation.com
Mike Grinager, Brenton Engineering Co., 320-852-7705
John Gunst, POWER Engineers, 208-288-6100
John-Paul Saenz, Haskell Co., 904-791-4500, john-paul.saenz@haskell.com
Larry Keener, International Product Safety Consultants, 206-283-2897, lkeener@aol.com
Andy Hansbrough, Kollmorgen, 540-633-3405
Bob Estes, Middough Inc., 630-756-7000
Alan Shema, Mocon, 973-839-4636, ashema@mocon.com
Tim Kent, Raque Food Systems, 502-267-9641
Leo Petrokonis, Rockwell Automation, 717-747-8200
Jason Jensen, Thiele Technologies Inc., 920-693-2423, jason.jensen@thieletech.com
Creative containers can pose package system challenges
Designing an exciting new package is the easy part. Getting the materials to run on machines engineered with the old package in mind is where things get dicey. Before testing the integrity of a new container, determine what equipment modifications will be needed to make it machine properly, advises Alan Shema, product manager for consulting/technical services at Mocon Inc.“People are pushing production volumes to the limit, and when you add a new package to the mix, you have to start at square one and determine if the machinery can deliver products with the right package integrity,” he cautions. “What are the heat limits of your sealer? Will the equipment deliver too many leakers or pouches with pinholes? The fix may be fairly expensive.”
The shift from glass jars and metal cans to flexible containers and other modern packages has created demand for testing services that go beyond Minneapolis-based Mocon’s traditional work in gas-permeation rates and headspace analysis. Newer materials usually don’t deliver the same protection as the materials they replace, prompting the firm to add accelerated aging studies and MAP system audits to its service pallet. Food producers also need microbiological review, and Mocon has partnered with microbiologists and other specialists to create a one-stop review service it calls Advanced Packaging Solutions (APS). Manufacturers want to optimize shelf life, and that requires accelerated studies of product degradation.
Much of APS’s early work has involved MAP packaging. Although inert gases have been used to stabilize packaged foods for years, “in the last five to 10 years, the science has progressed for each specific food product,” says Shema. The old rules of thumb might dictate thicker films or more expensive gases than are actually needed. Before transitioning to a different gas mix and thinner film, however, an ounce of lab testing is worth a pound of product recall.
Conquering convention with innovation
When Alf Taylor first considered building a vertical form/fill/seal (f/f/s) machine for snacks, conventional wisdom held that it was impossible to push speeds beyond 50 bags a minute, and the experts cited no less a physicist than Galileo to justify their belief.The problem was a misinterpretation of the work of Galileo, who most famously demonstrated the motion of falling objects was not dependent on weight but also that aerodynamics worked against less streamlined objects.
“Some of the most credible engineers in the industry said, ‘You can’t run chips at a high speed because they don’t flow at a high speed,’” recalls Taylor, an engineer and founder of TNA Solutions, Sydney, Australia. “The problem was that the people designing the machines at the time didn’t understand the physics of the sheet-metal transfer chute.” To the naked eye, potato chips appeared to float when descending, “when in fact they were following a different trajectory.”
The addition of scales to vertical f/f/s would come later, and the only machines on the market in the early 1980s were large, intermittent motion mechanical systems. Horizontal units, on the other hand, were continuous, and Taylor and his engineering colleagues modified one of those designs, turning the machine on its end. “It wasn’t pretty, and we had every problem under the sun, but after five days, we were running at 90 bags a minute,” he recalls. Instead of embracing change, the innovation was greeted with “an allergic reaction,” he adds. “In 1993, the senior engineer of a firm told me, ‘You can’t run at 130 bags a minute’ while the two of us were standing next to the machine that was doing it.”
Faster machines are available today, and filling systems that deliver more output, less waste and better quality will be critical in developed markets where automation must replace human labor if the manufacturing base is to survive. “Why go to China,” Taylor asks, “if you can produce at the same cost in the US, Europe or New Zealand?”
