A key aspect of food and beverage production involves the mandatory marking and verification of manufacturing (MFD) and expiration (EXP) dates and lot codes on the product packages. These codes are integral to identifying exactly where and when the product originated, and demand cost-effective systems that can report clear and reliable results to prevent packaging errors. As an added challenge, these lines often involve the scanning of multiple types of products simultaneously.
Based in Ho Chi Minh City, Vietnam, Pacific Hi-Tech has spent years helping food and beverage companies across Vietnam craft efficient, streamlined production-line solutions. In their experience, many vision systems experience issues related to these printed MFD and EXP codes.
Examples of the varieties of packaging, including MFD and EXP code, that pass on a single production line.
Sometimes the code is applied before the surface is fully dry, resulting in smudges; other issues could be related to operator errors in setting incorrect identification codes. These errors, and others similar, can lead to line stoppage when checking the absence/presence of printed code. In their work with Suntory PepsiCo, Pacific Hi-Tech sought a solution that would readily be able to detect missing code or incorrect MFD and/or EXP date code on products.
Let it flow
One of the largest producers and distributors of beverages in Vietnam, Suntory PepsiCo, has five manufacturing facilities nationwide, and a long history of successfully developing beverages for the Asia market. Not surprisingly, the company has a broad range of product packaging needs that would present a challenge to most marking systems.
“Suntory PepsiCo has many types of products, each with different sizes, properties, and components,” Mr. Pham Ha, project manager for Pacific Hi-Tech, explains. “Due to limitations on their ability to change the position of the printed code on the packaging—many products have registered copyrights on the shape and location of print code—it is necessary to design a system that conveniently accounts for every possible product permutation.” Pacific Hi-Tech was commissioned to develop a solution for these facilities; they sought out Matrox Imaging because, as Mr. Ha, notes, “It's easy to see the superiority of Matrox's algorithms over the algorithms of rival companies in solving similar problems.”
Diagram of the production line running from the Matrox Imaging vision system.
The algorithm in question is String Reader, a tool for character recognition that uses geometric features to quickly locate and read text made up of solid characters in images. Available in Matrox Design Assistant software, String Reader handles text strings with a known or unknown number of characters, accommodating changes in character angle with respect to the string, aspect ratio, scale, and skew, as well as contrast reversal. The Matrox 4Sight GPm, a powerful vision controller paired with Matrox Design Assistant, rounds out the vision system, which also comprises a FLIR USB 3.0 camera, a detection sensor, and LED lighting.
Stringing together a solution
The production lines at the Suntory PepsiCo pose continual challenges due to the stability of the conveyor belt as well as restrictions in its length; this results in inconsistent uniformity of the inkjet printing. Moreover, the liquid inside the product can blur the distinction between the image background and the foreground where the identification information is printed.
The production line as it scans cans for MFD and EXP codes.
Evaluating the possible options, Pacific Hi-Tech found that the Matrox Imaging String Reader algorithm was uniquely suited to the production conditions. “String Reader offers tremendous flexibility in terms of the code it can read,” explains Mr. Ha. “When the code position on the product is optimally clear, the vision system will employ String Reader to detect the wrong code or expiry date that the customer has set. In instances when the code is obscured, Matrox Design Assistant software automatically switches to presence/absence check mode. For our customers, that level of system intelligence is exceptional.”
The system encompasses a Matrox 4Sight GPm mounted in a secure cabinet above the production line. A connected camera takes images of each MFD and EXP code, while Matrox Design Assistant software checks for illegible code—whether smudged, obscured, missing strokes, or absent entirely. If the code is sub-optimal for any reason, the integrated ejector will remove the problematic product from the line.
Close-up of the Matrox Design Assistant operator interface.
Matrox Design Assistant’s integrated development environment (IDE) allows developers to design a graphical web-based operator interface for the application. Another advantage of the Matrox Imaging vision system is its autonomous capabilities; the system can run independently, or the operator can interface directly with the system, as necessary.
Future verification projects
Although the Suntory PepsiCo systems have only recently come online, Pacific Hi-Tech already sees opportunities for developing future identification verification projects using a similar vision system along with a Matrox Iris GTR smart camera. A new line-scan system—based on Matrox Imaging Library (MIL) software and the new Matrox Rapixo CXP frame grabber—is likewise under consideration. The exceptional rate of presence/absence and text string reading provided by the Matrox Imaging system has helped Pacific Hi-Tech offer their customers peace of mind and the assurance of avoiding costly production-line errors.
“The advantage of the Matrox Imaging String Reader algorithm, compared to competing OCR algorithms, is that it was developed as a flexible reading tool that can be used in different applications,” Mr. Ha concludes. “The Matrox Imaging algorithm is very intelligent. String Reader is able to handle imperfections easily, saving time, effort, and cost for the operator.”
Written by Katia Ostrowski, Marketing Writer, Matrox.