Optical Inspection of Pharmaceutical Labels

Sept. 19, 2012
High-quality labels and stickers optimize logistics processes and protect against damage caused by counterfeit products. In a new labeling system for pharmaceutical cartons, the intelligent vision system In-Sight Micro 1400 inspects the exact position of small information and data carriers so that defective products can be reliably removed.

Artur Theis GmbH & Co. KG of Wuppertal, Germany has decades of expertise in the field of manufacturing folding cartons for pharmaceutical products. In its latest machine, Artur Theis GmbH equips the high-quality packaging with different identification and information carriers. These include labels with 1-D codes, genuine lettering and holograms, as well as bollinos, pharmaceutical stickers which can be partially or completely removed from the packaging. the, The Cognex In-Sight® Micro 1400 intelligent vision system with PatMax® pattern matching technology is integrated into the new Artur Theis machine and checks the exact positioning of the labels. The In-Sight Micro 1400provides extremely high repeat inspection accuracy within specified tolerances and identifies possible defective products so they can be reliably removed.

Narrow margins
The new machine can affix labels, stickers, and bollinos to up to 200 different types of folding cartons and check that they are in the correct position. Zertrox GmbH & Co. KG of Aachen implemented the image-based testing station for the machine. Zertrox specializes in measurement and control technologies. The company is a systems integrator working with Cognex to assist companies in the design, development, and operation of PC-based measuring and image processing systems and laser controls.

In the past, Artur Theis performed the inspection of product characteristics with the human eye. However, the increased level of automation in the pharmaceutical industry made it much more difficult to inspect packages for important information and data carriers. In addition, affixing additional information on the packaging by the pharmaceutical manufacturer requires far greater precision than the human eye can provide. This includes the use-by date, product, and lot numbers as well as information for healthcare providers such as health insurance funds. If the labels and stickers are not perfectly aligned to the central features of the folding cartons, then the additional information cannot be applied correctly.

Exact position
One of the biggest challenges in this process that only the In-Sight Micro 1400 with PatMax was able to handle was the identification of the labels at extremely high volumes of up to 40,000 cartons per hour. Due to the large variety of products with very different label shapes and colors, it could not be assumed during the system design that all of the boxes would reach the testing station on the conveyor belt with the same position accuracy. The In-Sight Micro 1400 intelligent vision system had to orient itself to certain predefined geometric features of the cartons in order to set and precisely determine the position of the labels and stickers in relation to it. This was made possible by the image-based PatMax pattern matching technology that determines all of the important position values without errors-even under variable lighting and position conditions and despite changing angles, sizes, and shading.
The illumination of the testing station is provided using an LED ruby light. The trigger pulse for the In-Sight Micro is provided by a fluorescent sensor. This sensor recognizes the outer edge of the flat boxes using the fluorescent properties of the box in contrast to the non-fluorescent material of the conveyor belt.

Ease of use
In selecting the In-Sight Micro 1400, the packaging experts of Artur Theis were also impressed by its small size - (30 x 30 x 60 mm). The complete and fully self-contained system is particularly well suited to measuring, guiding, inspecting, counting, and identifying products on fast-moving production lines. Besides its small size, the In-Sight Micro also offers particularly flexible mounting options.

An important part of the intelligent vision system is the proven Cognex image processing library. Using this library, the operating software can be used for an extremely wide variety of image processing tasks. The calibration of new products in Artur Theis' new machine is very simple and can be carried out by the machine operators themselves. For new products, they simply set a characteristic feature of the packaging in relation to a characteristic feature of the sticker using the Cognex In-Sight Explorer software that comes with the In-Sight Micro. Based on the stored master job, product changes can be performed in just a few minutes, even for completely new folding boxes.

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