New features of automatic optical inspection systems (AOI) for efficient and cost saving quality control

H. Oerley, Dr. Schenk GmbH, Germany

AOI systems for web control
Standard systems for optical quality control of filtration media production are readily available. With increasing quality requirements in filter media production producers need to look for new developments though that meet these stricter requirements.

ABI – Adaptive Background Illumination
Digital cameras used in filter material inspection are faced with a rather noisy signal, originating in the characteristic material structure. Consequently the AOI cannot detect small defects. Adaptive background illumination eliminates most of this inherent material noise, rendering even smallest defects visible.

Virtual X-Ray
The light power of LED illuminations can be switched at high frequencies (multiplexing) and a single LED illumination can feature multiple intensities. By sequentially switching to high intensity, an image similar to an X-ray image is obtained. This very clearly shows inclusions and foreign particles in filter media.

Formation Analysis
The homogeneity of filtration media has substantial influence on the function of the end product. For example, big variations in material thickness affect the correct function of the filter. Using the same cameras tasked with the detection of local defects, modern AOI systems provide tools to evaluate material properties such as grammage, cloudiness and homogeneity in CD- and MD-direction:

MCI – Multi-Color-Illumination Technology
With MCI Technology, a monochrome camera, powered by different illumination colors, picks up defects such as foreign fibers or dirt patches. This solution offers the unique combination of monochrome cameras’ high performance and lower price with the capability of detecting color defects...

Session: F2 - Filter Media - Quality Control and Pore Size Analysis
Day: 12 October 2016
Time: 16:45 - 18:00 h