Vision systems in the packaging world
February 8, 2017
by Laurie Gorton
Vision systems can read UPC and date codes for legibility and correctness.
Vision systems answer the inline inspection need to verify product shape, size and color and check on package conformity. “Vision systems are typically installed ahead of packaging, but you can also use them after carton-packing to verify it was loaded correctly and closed properly,” said Joe Crompton, director, controls engineering, Blueprint Automation (BPA). “They can detect missing products and whether package flaps are sticking up.”
A typical use for BPA vision systems is to assist its Delta robot carton loaders. “The vision system guides the robots that load cartons,” Mr. Crompton continued. “If the product doesn’t pass inspection, it’s not given to the robot to pack.”
Such systems are growing more capable. “It used to be that every robot loader needed a dedicated vision system,” Mr. Crompton explained. “Now a single system can guide four robots.”
High-speed cameras are the vision system’s eyes. Recent advances have added color as an option, where once the choice was only grayscale systems. “We also use thermal cameras, and we’re seeing more 3D cameras checking product conformation,” Mr. Crompton noted.
High-resolution capability also improves performance, according to Andrew McGhie, business manager, North America, EyePro Systems USA. “Using the high-resolution color camera, the inspection system can identify spots on the surface of a product that differ from the product’s usual color,” he said. “In the shadow of FSMA, this capability has been of renewed interest to many customers as it can help to ensure that safe products are being delivered to consumers.”
Applications include checking for the presence of snack food seasoning ingredients to prevent mismatches between a package’s ingredient list and the actual seasoning delivered.
Another use detects ash spots on pancakes. Considered to be defects, such spots are a continuing problem caused by the nature of the griddle baking process. Even subtle features of packaging yield their secrets to modern vision systems.
For instance, vision systems can read UPC and date codes for legibility and correctness — an important aspect in some markets where consumers are picky about such information. “These are good examples that demonstrate the perception of quality is just as important as quality itself,” observed Mark Lozano, sales manager, TNA North America Ltd.
A trend is to use inline checkweighers, vision systems and metal detectors or X-ray systems as a combined data-gathering system. “This allows these functionalities to be included on the line in a smaller footprint and allows data from these devices to be included in a single database to help document critical control points,” Mr. McGhie said.
This led EyePro to focus on integrating inspection data with SCADA automated line management systems. This ensures signaling of product changeovers to the inspection system and enables reliable product tracking. “We are also able to alert the line SCADA system of any out-of-spec situations so that they can be attended to in a timely manner and any affected products isolated by rejecting them off the line,” Mr. McGhie said.