Quality assurance and quality control are of the utmost importance for food manufacturers and processors. Sensors and other analytical technology can be used on the processing line to improve the safety of the finished products, and also of production personnel.


Sensors and technology

“Quality control equipment for processing lines is designed with both food safety and safety of personnel in mind,” says Melissa Rossi, director of marketing & customer service, Teledyne Taptone, North Falmouth, MA. 

“Inspection equipment is designed to inspect for defects in packaging that can affect consumer health as well as product esthetics. Leak inspection of food products ensures that there are no micro openings that could allow insect or bacterial contamination. Leak inspection also assures that air doesn’t enter the packaging causing product spoilage by compromising optimal storage conditions,” she adds.

Vacuum and pressure inspections also assure that appropriate conditions within each package exist to ensure product integrity and food safety, Rossi notes.

“Label and code inspection confirm that product is properly labeled for consumers and that date codes are correct before they leave the plant. Data collected during all manufacturing processes provides manufacturers with vital information on manufacturing conditions of each batch or lot of product that has left the facility. Safety stops on all modern equipment provide safe operation for equipment running at full line speeds and help prevent accidents.”

Rossi says that all food types—from solid to liquid, fresh to canned—can benefit from the variety of sensors available for quality testing.

“From metal detectors, foreign object detectors, and visual inspection cameras to leak and fill level inspections, the range of testable products is vast. While all products can’t be tested with 100 percent assuredness for safety, the majority of common and less common contaminants can be inspected for and removed before defective or harmful product reaches the consumer.”

Sensors and technology can overall improve plant efficiency, too.

“The benefits to on-line, full line speed testing equipment means that plants can process food at astounding rates while still testing each and every product before it leaves the processing line. In addition, the data sent from the equipment allows plants to actively monitor product for trends that can prevent negative events before they occur, by catching anomalies and adverse events before large amounts of product are affected, therefore reducing waste and reducing cost,” Rossi comments.


Lubricating sensors and equipment

Otto Oosterwijk, owner and CEO, Interflon USA, Swanton, VT, says that as a lubrication company, they are directly concerned with equipment safety—as pertaining to the condition of the equipment—and food safety, as pertaining to the type of lubricant being used, and the risk of contamination of food products.

“Lubrication has a great deal to do with safety for equipment; that is, keeping everything working properly and safely, and helping to prevent breakdowns,” he says. “While industrial lubrication is not typically thought of as something that directly pertains to food safety, in fact, it's critical that companies do use the appropriate grade of lubricant when there is a possibility that it may come into contact with consumables. NSF H1 (food-safe) lubricant is typically required in such a situation.”

Oosterwijk says that automatic lubrication systems sometimes have sensors that measure where a chain and its attachment are in its cycle, and they in turn on and off the automatic lubrication system at the precise moment for spray lubrication. 

“It clearly affects safety and quality, as it can meter less oil/grease, and limit overspray, and mess. It also reduces the need for people to do the job in a potentially dangerous environment, thereby increasing safety in the plant. Obviously we see an increase in the quality side, as we can now better control the amount of lubricant needed—reduction in cost, adding to the bottom line—while decreasing the risk of contamination.”

Food plants want to minimize the risk of contamination of their food products by chemicals such as lubricants, he says, and [Interflon] supports this in multiple ways.

“One is through the formulation of our products, by making them stick better and by making them perform better, which reduces the amount of product required. Another is by helping with precise application. By using sensors, the exact amount of lubricant can be applied in exactly the right place. Less product used means less risk of dripping and contamination,” Oosterwijk explains.

“Any type of food product that passes through an automated assembly line, either in the production or packaging phase, is suited to using lubrication sensors. We tend to deal mostly with situations in which lubrication is a challenge—i.e. poultry kill floors, professional bakeries, very hot environments, very cold environments, etcetera.”

RJ Francois, technical advisor, Interflon USA, says that food processing sensors such as acoustic measuring devices [can be] used to quickly determine lubrication levels in equipment with a lot of moving pieces, such as bearings, chains, wheels, etc.

“These devices, such as the Adash Vibrio, are used to detect the amount of vibration present. From this information, it determines the current lubrication level, and can provide immediate continuous feedback as more lubricant is applied, alerting the operator immediately when the optimum level is reached. Because overlubrication is just as dangerous to equipment safety as underlubrication, acoustic sensors are very helpful in telling the operator exactly when to stop the application of more lubricant,” he says.

Cory Fuller, technical advisor, Interflon USA, says that another type of sensor is the optical variety.

“Optical sensors may detect the approach of wheels that require regular lubrication to compensate for the presence of contaminants, such as flour dust, which acts as an abrasive and quickly destroys moving pieces such as bearings or the bushings in chains,” he notes.

This type of sensor is also used in areas where equipment is subject to frequent sanitation regimes, such as on the kill floor of a poultry plant, Fuller adds.

“Daily hot water and chemical sanitation tends to wash lubricants away, leading to regular breakdowns and the need for frequent replacement. An optical sensor can be calibrated to send a jet of lubricant to the appropriate part of the wheel as it passes the nozzle, thus extending equipment life.”

John Leslie, technical advisor, Interflon USA, says that yet another type of sensor may determine the amount of tension remaining in a chain.

“As a result of normal use, every chain will eventually appear to lengthen or stretch out. This is actually an illusion caused by the fact that tiny amounts of material wear away from between the pin and bushing, creating a very small amount of play,” he explains.

“In one chain link, this is scarcely noticeable, but in a chain with thousands of links, it will quickly add up. Lack of proper lubrication will cause this to happen much more quickly. Industry standards usually dictate that a chain should be replaced when it has 'stretched' no more than 3 percent. That is, if a chain is 100 meters long, it should be replaced as soon as it 'stretches' to nearly 103 meters,” Leslie says.

“Automatic tensioners can keep a chain taut to a degree, but they fail when too much lengthening has occurred. Slack chains are dangerous to both equipment and humans, and they are expensive to replace. Using a sensor to keep on top of chain lubrication will greatly increase its life span, which in turn will not only result in a safer working environment, but can greatly improve a company's bottom line.”

Related - Slideshow: QA/QC and food safety technology for process improvement