Machine vision verifies printed codes at 800 cans per minute
A food processor fills an average of 800 cans per minute with a wide range of products such as vegetables, fruit and soup. An important challenge for the company is ensuring that the code printed on the bottom of each can matches the product in the can. A mismatch runs the risk of creating an unhappy customer or, even worse, an allergic reaction. In the past, there were concerns that operators might accidentally set up the printer to generate the wrong code or that the printer used to apply the code on the can might fail to produce a readable code. These concerns have been overcome with the installation of a machine vision system that reads the code on the bottom of the can in just 60 milliseconds, enough time to reject cans with incorrect or unreadable codes. The vision system uses pattern matching to orient the code regardless of its radial position then uses optical character recognition to read the code and match it against the product currently being produced on the line.
Current and upcoming food traceability legislation requires that food processing companies have systems in place to provide a trail of information that follows each food item through the supply chain. To ensure food safety and efficient recalls, manufacturers must be able to identify and locate any item in the food supply chain and quickly trace it back to its source and forward to its destination. To achieve this, many companies are in the process of implementing 2-D barcodes, vision systems, and image-based ID readers in order to ensure the safety of the supply chain. The food processor in this application decided to begin reading the code on the bottom of each can to be sure that it is readable and that it matches the contents of the can. The goals were to prevent mislabeled products from reaching customers, prevent accidental product mixing on the line and prevent shipping of mixed products to customers.