Pilot Plants put to the test
What works in the lab might not be feasible on the line, and a pilot plant test will quickly determine that. Can process changes be accommodated on an existing line? Is small-batch production scaleable to full-size production? Will new equipment deliver as advertised for a processor’s unique product? The answers can be found at pilot plants, and a growing roster of state-of-the-art facilities are available to serve American processors.
An example is the Asep-Tech USA plant in Springfield, Mo., a joint effort of Dairy Farmers of America and Stork Food & Dairy Systems Inc. The 5,000 sq. ft. facility has been processing and filling extended shelf life test products for two years, and in July it was ruled to be FDA compliant for aseptic filling at ambient temperatures for low-acid foods under manufacturing conditions.
“As far as I know, there is no other R&D center in the United States that is FDA compliant and can manufacture food products and put them in a grocery store for people to buy,” says Jan Kuiper, executive vice president of Stork. Attaining that status took five years and puts Asep-Tech in position to not only test value-added aseptic products but also produce limited quantities for test marketing. Up to 3,000 packaging units ranging from 4 to 64 ounces can be produced per hour.
“The future of UHT is in value-added products, not aseptic white milk, in particular when the package or the product can’t withstand retort,” Kuiper believes. Gaining FDA approval for the low-acid aseptic filling machine was therefore critical. It gives Asep-Tech the ability to test a wide range of pumpable foods and packaging options. The only difference between the plant’s filler and the commercial unit at Morningstar Dairy in Virginia is that Morningstar’s fills 12 lanes of containers, while the plant’s unit has two lanes.
Scalability isn’t an issue, but it can be at other pilot plants. Painstaking effort and engineering time has been invested by equipment makers to produce miniaturized versions of spray dryers, scraped surface heat exchangers and other processing systems. Miniaturized units ease the transition from bench-top processes to industrial production, but clients understandably are reluctant to place million-dollar bets that they truly emulate commercial systems.
“Miniaturized systems are valuable for establishing the technical feasibility of a process and perhaps generating some tending data, but for the most part they are not scaleable,” says Phillip S. Tong, dairy science professor and pilot plant director at California Polytechnic State University in San Luis Obispo. “They provide feasibility testing to make sure you don’t do something like plug up the dryer in your plant when you attempt to run a new product or process, but scalability is an issue.”
Mini-Me PlantsCal Poly’s six-year-old pilot plant boasts a wide assortment of dairy-related processing and packaging equipment, including a reverse osmosis system and a continuous butter churn/crystallizer that cost almost as much as a commercial unit but is a fraction of the size. Tong hopes to have a miniature UHT unit in place early next year to help meet growing industry interest in ESL refrigerated foods. Among the mini-UHT units being considered by Tong is a system from MicroThermics, a Raleigh, N.C., firm that manufactures lab equipment and performs client tests in its own miniaturized pilot plant.
“There is a perception problem, but we invite people to see us perform scalable tests with their own eyes,” insists David Miles, vice president of MicroThermics. “We use a number of methods to build the heating curves and calculate the time and temperature for scale up.”
Miniaturized equipment was considered when FMC Foodtech recently expanded its technology and training center in Sandusky, Ohio. In the end, the staff elected to install a commercial-sized equipment. “We would have been forced to spend a lot of time and effort making [miniature] equipment and then testing and comparing performance with full-scale equipment, then endless hours discussing and debating the statistical reliability of our scale-up assumptions,” explains Bob Swackhamer, center manager. “There are so many variables in running product on full-size equipment. Even if you can scale up, you have to convince the customer that the test was valid.”
Built in 1989 at a cost of $5 million, the Sandusky center serves multiple functions. Processors send staff members there for training on the operation and maintenance of processing and refrigeration & freezing systems, and about 400 product tests are conducted each year. An additional $3 million investment added several pieces of new equipment, notably a new-generation JSO-V impingement-style convection oven that is undergoing validation tests on performance and variation. The unit is 32 feet long and has a 42-inch wide belt. “We could have built a little Tonka version,” Swackhamer laughs, “but then we’d have to run mini-hamburger patties through it, and people want to see results with full-size patties.”
It’s a small step from pilot plant extrusion to commercial application at the University of Nebraska-Lincoln, where a Wenger TX-57 twin screw extruder can handle throughputs of 300 lbs. an hour and batches as small as 50 lbs. “You’re still going to have some bumps in the transition to production, but it’s a lot more scalable than the extruder we had before,” according to Laurie Keeler, general manager of the university’s five pilot plants.
Extrusion and tortilla processing are strong suits at the facility, and everyone from local entrepreneurs to major food companies book pilot-plant time. “That’s our money maker, and we’re booked out two months or more in that plant,” she says.
Soy-based products and fortified foods account for a growing proportion of the plants’ product trials, reflecting general trends in the industry. Meat analogs with soy and gluten require twin-screw extrusion, and those types of tests account for about a third of the plant’s projects, she estimates. Whey protein concentrates are another area of intensive product development, and spray drying is the applicable technology. Nebraska has a small dryer for testing and research; a better facility choice is Niro Inc.’s Columbia, Md., headquarters, where food & dairy pilot plant activities have been consolidated with technology for other industries.
Multiple fluid bed and spray dryers are available for research and prototype work. They range from the FD Micro unit that dries “a few hundred grams per hour for pharmaceuticals’ testing to dryers that are about 50 meters high,” according to Mads Skaarenborg, marketing director. “Clients come to us and ask, ‘Can you dry this to a powder or a particulate?’ and we guide them to the appropriate dryer and the most appropriate atomizer configuration, whether it’s rotary, pressure nozzle or pneumatic nozzle.
“All of our pilot plant equipment is fully scalable to an industrial size,” Skaarenborg insists. Processors with in-house technical expertise who want to conduct tests in their own lab can purchase the Mobile Minor, a spray dryer on wheels that measures 6 feet in height and evaporation rates to 15.4 lbs. an hour.
Processors with more consumer-oriented product development in mind are more likely to wind up in Denton, Texas, at Tetra Pak Inc.’s pilot plant. Two separate processing systems are maintained: an R&D-oriented unit and a scalable aseptic configuration for batches of 80 to 800 gallons. Virtually every pumpable food except puddings have been run at the center.
“Product testing much much folows trends in the industry,” says Julie Hassler, qualitiy specialist for aseptic carton systems. “Nutritional products are huge here, partly because of their never-been-run aspect and because of the packaging options available.”
The plant is a registered Food Canning Establishment and FDA-approved for low- and high-acid foods. FDA approval is anticipated early next year for a linear aseptic filler (LFA) that will allow the plant to fill plastic containers with aseptic products, much like the Asep Tech plant. Until then, small quantities of aseptic products are manually packed in a glove-box unit.
The plant also is validating a pilot-scale version of Tetra Pak’s new Recart machine, a retort unit that processes products in paperboard laminate packaging. While production units are massive, the pilot retorts and filling system fit into a 20-ft. long shipping container.
Although the plant is 18 years old, processing and packaging equipment is state of the art. “The aseptic tank is one of the few original components; everything else has been replaced,” notes Charles Sizer, who served as plant director when it was in Buffalo Grove, Ill. “That plant has outstanding mixing and blending capabilities and wonderful components, like the Lifwifier high-sheer mixer.”
When the plant moved south, Sizer shifted to the National Center for Food Safety and Technology. A joint partnership between FDA, Illinois Institute of Technology and private industry, the center gets involved in pilot plant projects on the leading edge of food technology. Juice processing with UV lamps can be done, though the number of commercial applications can be counted on one hand, and NCFST has five ultra-high pressure presses.
NCFST’s process equipment is more exotic than what is typically found in a pilot plant. That may or may not be important, depending on the particular needs of the client. The opportunity to determine process and product compatibility is the reason food manufacturers turn to pilot plants in the first place, and selecting the appropriate pilot plant assumes the equipment is comparable and scalable to what is in the client’s plant.
Selection decisions also turn on a number of factors. Pilot plants operated by equipment manufacturers serve multiple functions, including system showrooms that provide an opportunity to run product on equipment a notch or two above the norm.
The level of expertise needed also plays a part in pilot-plant selection. The equipment in the University of Wisconsin’s plant is unremarkable, but the specific expertise of its faculty and staff make it one of the top dairy development centers in the world.
Sourcing a pilot plant that meets a processor’s needs for confidentiality, technical support and scalability while remaining within budget can be a challenge. In all likelihood, a match exists; it’s simply a matter of finding it.
Pilot Plant Resource Guide
Plant Capabilities and Contacts
Sterile processing & packaging
Jan Kuiper, 770-535-1875
San Luis Obispo, Calif.
HTST, evaporation, etc.
Phillip Tong, 805-756-6102
Dairy drying, evaporating, packaging, etc.
David Barbano, 607-255-5482
Frying, coating, freezing & refrigeration
Jan Gaydos, 419-627-4303
John Miles, 919-878-8045
Flash, fluid bed and spray drying
Mads Skaarenborg, 410-997-6617
UV, high-pressure, UHT, aseptic, retort
Chuck Sizer, 708-563-1576
North Carolina State Univ.
Seven plants, including aseptic, dairy, produce, meats & seafood
Gary Cartwright, 919-513-2488
Tetra Pak Inc.
Blending/mixing, thermal processing, aseptic packaging
Brian Thane, 940-565-8910
University of Nebraska
Dairy, bakery, protein foods, dehydration, extrusion, MAP
Laurie Keeler, 402-472-7803