Vision systems are primarily designed to gauge day-to-day physical dimensions and product characteristics, but they are increasingly being implemented for safety reasons. “In the past 10 years, the use of high-resolution cameras has also helped detect foreign material on the surface as well as the top and bottom of a product,” said Andrew McGhie, business manager, North America, for EyePro System USA. “It’s an added layer of protection for customers.”
Vision systems not only can find and reject defective goods but also can be used to investigate contamination issues upstream in the process. “The inspection system can be set up to activate an alarm if a product is rejected because of a foreign material defect. This alerts the operators to this ‘foreign material’ situation so that it can be investigated in a timely manner,” Mr. McGhie said.
Because many bakers and snack food producers now work with colored tools, components and disposables in the plant environment, detection via vision systems is easier. “You see more manufacturers doing things like using blue rubber gloves instead of white ones, or using de-panning cups that are brightly colored instead of being a similar color to bread as they were in the past,” Mr. McGhie pointed out.
Vision systems also detect the presence of grease or oil on a product. “Even though that is food-grade and not a safety risk, if a customer gets a loaf or bun and sees grease on it, they may see it as a risk,” Mr. McGhie said.
Inline X-ray systems provide another layer of protection for food manufacturers looking to enhance product safety. “X-ray systems have the ability to detect dense contaminations while also inspecting other quality attributes such as shape and dimension. They also have the ability to identify broken or missing components,” Robert Rogers, food safety expert at Mettler Toledo Safeline, Inc. said of systems like Mettler Toledo’s X33 X-ray machine.
Meanwhile, processors have additional tools to ensure product quality and safety, including materials that coordinate with metal detection and X-ray systems. Habasit America offers various solutions to prevent contamination, such as the presence of plastic that can break away from machinery or come from other sources. “In conjunction with various OEMs who make inline inspection machines, we've created both metal-detectable and X-ray materials that will trip an alarm should a piece of plastic be present in the food or package being inspected,” said Kevin Dahill, area sales manager, plastic for Habasit. “That package will then get rejected or kicked out of the line to inspect further or discard completely.” He added that while metal-detectable materials are more commonly used, X-ray has “gained momentum” in recent years.
Additionally, manufacturers can deploy checkweighers for safety reasons as much as for determining target weight. Today’s checkweighers can control errors linked to product defects and can help in traceability if problems related to contaminants occur. For instance, Heat and Control offers a series of Ishida checkweighers available with integrated metal detection and reject systems. Doran Scales, Inc. has introduced a Selecta in-motion checkweigher that enables 100% production inspection and can be configured with the company’s Synapse software for data collection and quality control. The software lets users see the efficiency of the production batch and the number of rejected items, among other functions.
Taken in totality — and several suppliers offer a range of detection and inspection machines under their company’s umbrella — inline inspection systems are increasingly embraced by food processors seeking to prevent recalls and become more efficient in finding and rejecting problematic products. “I’ve been doing this for 20 years, and in the past several years, more customers are saying they see the value of 100% inspection,” Mr. McGhie observed. “They know what they are giving to customers, and they are helping be more food safe.”