Manufacturing AUTOMATION

Features Factory
Factory fresh: Food safety in an automated plant is common sense


June 12, 2009
By Michelle Morra

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Introducing a new robotics system in any manufacturing environment automatically places the robot at risk. Protecting the machine’s sensitive components from the work environment becomes a priority. But if you work in the food sector, you have an additional responsibility: just as the food mustn’t harm the robot, the robot mustn’t introduce contaminants into the food.

Sanitation is everything, so the robot must be able to withstand daily high-pressure wash downs with hot water and sanitizers. It must be rustproof for protection from corrosive cleaning chemicals. The electronics box of the robot, and wherever possible its arm, must be covered during wash-downs.

These are the relatively straightforward challenges of an industry that is otherwise, thanks to technology that can increasingly handle food directly, a rapidly growing market for robotics.

What lies beneath
An investigation into the listeria outbreak at Maple Leaf Foods in Toronto that killed 20 people in the summer of 2008 concluded that the bacterium likely originated from deep within the inner workings of a robotic meat-slicing machine. But the machine was not to blame, says its manufacturer. The nearly 300 Formax S-180 meat slicing machines at processing plants around the world have produced an estimated 2.3 billion kilograms of sliced meat for 13 years without incident, a spokesman for Formax said in a press release.

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Officials found the listeria only when they disassembled the meat slicer. The company had exceeded Formax’s sanitization instructions, but had not regularly dismantled the machine, a “very significant mechanical process.” Since the investigation, Maple Leaf will now disassemble its 14 Formax S-180 meat slicers every week for cleaning, but might have to replace the equipment if that process proves impractical.

Food contamination starts with a particle of something – meat, a human hair – that might, under certain conditions, harbour the formation of bacteria. Depending on factors such as temperature, humidity and how long before someone washes that microscopic particle away, it can grow and spread. In worst-case scenarios, the mass production or processing of food causes the contaminant to be folded or distributed into food on a grand scale.

Food particles don’t stay fresh for long. Gauri Mittal, an engineering professor at the University of Guelph who has done research related to food safety, says there are more pathogens [disease-producing agents such as viruses or bacteria] in a person’s kitchen than in the bathroom.

“Sometimes we do get microorganisms, and we don’t get sick,” says Mittal. “But if there is a high concentration of them, or if our immune systems are weak, they can kill us.”

He says one drop of milk contains up to 4,000 microorganisms, and one glass of milk contains millions. “We get them every day, but when you get more that are pathogenic, there may be a risk. If there’s moisture, pathogens can linger for a long time. If they’re around for a long time, some pathogens become spores that have defence mechanisms and can survive for years. Under the right conditions, they can germinate and start to reproduce.”

If you’re automating your food plant, the good news is that machines tend to be cleaner than people. Dick Motley of FANUC Robotics America, Inc. recalls that when an e-coli outbreak in a U.S. fast food chain in the ’90s made a lot of people sick, experts were certain that only a human being could have caused such a high incidence of the bacteria.

“There is no absolute control over accidental contamination by an employee,” he says.

Now we’re cookin’
Food processors have a responsibility to regularly inspect and clean their machines, but it’s up to the robot’s manufacturer to make that process as foolproof as possible. Besides wanting details of the design, exterior, shape and form, Motley says, “the USDA (United States Department of Agriculture) had a couple of key concepts that they really kept after us on: inspectability and cleanability.”

Those concepts, he says, went right into the design of FANUC’s new LR Mate 200iC Food Option robot and its M-430iA/2F Food Robot. FANUC has been in the palletizing business for decades, but has moved more into the upstream applications thanks to technological advances that make higher speed applications possible.

The intelligent LR Mate 200iC series of mini robots is designed to handle products in various industries and working environments, including food. It has no area where food particles can be trapped. A special coating can handle wipe-down and low-pressure rinsing and sanitizers.

Similarly, the FANUC M-430iA is capable of picking primary food and packaged products at speeds up to 120 cycles per minute on a continuous basis using visual line tracking. It, too, has a clean design with no food particle retention areas, to resist bacteria growth and rust, and can withstand the rinsing process after the caustic washdown.

Motley says robots in the food industry are a positive change from the alternative: the human hand. “Until recently, no technology has been able to replace some of these applications where human operators are dealing with raw materials that occur in nature, where no two pieces are alike.”

He still believes nothing can surpass the dexterity or the gentle touch of a human hand. The best the industry can hope for, he says, is to equal it with vision-guided systems. “Machines, however, are more consistent. Robots don’t get tired or distracted,” he says.

Nor do they incur traumatic or repetitive motion types of injuries on the job. Robots can survive dull and dangerous work.

Another robot that meets the rigid requirements of the upstream food sector is the new Meat Gripper from Applied Robotics Inc. The light-weight, end-of-arm tool allows for high-speed robotic pick and placers to pick up non-uniform pieces of food.

It can handle all types of meat, fish and cheese in various fresh, cooked, frozen and sliced forms, and can withstand hygienic wash-downs.

The Meat Gripper is easily inspectable and cleanable, says Applied Robotics’ engineering manager Clay Cooper. “For any automation design involving food, you typically look at it from immediate contact to the food going outward into zones.”

Any machine part that touches meat must not harbour bacteria. “The machine must be cleanable down to every facet, so there can’t be any cracks or crevices that bacteria can hide in.”

Sounds like common sense, but some machines might have a small cavity built in that could allow a puddle of water to foster bacteria. “All areas of a tool or machine should be washable,” says Cooper, “and have drainage by gravity where everything just flows.”

Because contaminants can linger, even the environment where robots are manufactured must be sterile. Automated Packaging Systems has created a robotic system that puts food into bags. The new FAS Sprint SidePouch Bagging System can bag at speeds up to 120 bags per minute. Its manufacturing environment was recently certified by AIB International, an independent international auditing organization, as being conducive to food safety.

The robotic system can be washed down every day for food packaging. Both the machine and the bags are manufactured in a clean room environment, which means there are no food or drink at workstations, and workers use hair and beard nets and other controls to prevent contamination. The plant also uses positive air pressure to prevent contamination from small airborne particulate and insects. The machine’s stainless steel construction, one-touch clean-out switch and 90-degree tilt action make the FAS Spring easy to clean.

While equipment producers must design cleanable and inspectable robots, food plants have a responsibility to follow manufacturer’s instructions for maintaining and sanitizing the machines daily, and to exceed these requirements as needed to comply with food safety laws.

If you’re inviting robots to the dinner tables of North America, they are welcome–but make sure they wash their hands.

Michelle Morra is a freelance writer living in Toronto.