Vision Inspection Systems Drive Profits
In-line, automated vision inspection can help maintain margins and reduce waste for packaging converters.October 2012 By Randy Freeman, GM - Packaging, QuadTech
With their fast changeover and high-speed capabilities, the latest generation of presses certainly provide the platform for a lean production environment in which waste is driven out of the workflow. But without reliable, high-performance press controls that enable the press to run uninterrupted at full speed throughout the run, these advances in press technology cannot be exploited to full potential. Solutions are urgently needed, not only because of demands for higher quality brand presentation, but problems such as errors on pharmaceutical or medical packaging can have serious consequences.
Thankfully, a new generation of systems are able to offer a standardized, objective means of measuring color and precision inspection, in-line, without compromising performance. Furthermore, systems are available that can handle the full variety of film and paper substrates, including transparent, supported, unsupported, and reflective types.
Color standardization is vital
A common industry color standard is increasingly necessary as brand owners insist on identical color consistency for product packaging at a global level. Spectophotometric measurement, using spectral response and L*a*b* values, provides the most objective way to describe color. But it is the frequency with which results can be taken that makes in-line solutions so much more reliable. While hand-held devices may be capable of taking a few readings during the course of a production run, the latest in-line systems have software powerful enough to take readings, from as many as 72 image targets, continuously.
In flexographic and gravure printing applications, an in-line inspection and color measurement system comprises a spectral camera, a video camera, a lighting system (to illuminate the target areas and ensure the substrate image is captured under suitable, uniform conditions), high-powered software to process the image, and a central data repository to enable at-a-glance viewing of print defect information and registration and spectral data, as well as communication with other systems in the workflow. The sensor and lighting are located after the final printing station.
An in-line inspection and color measurement system provides a number of important benefits: