Web film inspection system

Flaws in film affect the quality of the image produced, but the customary method of manual inspection by sampling is not only time-consuming but also wasteful, and it allows faulty film to be processed and packed for distribution. The purpose of the research was to build a significantly more accurate inspection system. To overcome the problem of inefficient flaw identification and unusable flaw-position data recording resulting in the inadequate elimination of faulty film, an advanced inspection system, based on infra-red machine vision incorporating a 940 nm LED light, was built. This system, which has been under trial for 2 years by Lekai, the largest film manufacturing company in China, recognizes flaws in the film, records and stores the flaw-position data; this data being passed to the packing line where the faulty film is automatically cut out. The results of this improved inspection system show a substantial improvement in quality control, efficiency, and considerable reduction of wastage. A surprising result was that previously undetected flaws in the film were discovered.