As large areas of the foils have usually been printed on, particles are not easily identified and are frequently interpreted incorrectly due to being partially covered by the printing. Finally, a challenge is presented by the fact that large-volume bags have an extensive area for inspection. The camera resolution for particle inspection is relatively low and therefore imprecise if the camera sensor is not adjusted.
A Multi-Stage Inspection Method
So, what solutions are available to the many and varied challenges that arise when inspecting large-format bags? With an effective illumination setup, careful positioning of the object to be inspected, and selection of the right background, it is easier to detect shadows and light reflections, as well as particle defects, print defects, and material defects.
To ensure a reliable detection of particles and an accurate distinction between particles and air bubbles or imprints, precise classification and fine-tuning is also required. For this purpose, the hardware and software in the inspection system must be perfectly aligned and adjusted to the specific requirements of the process environment.