A real time vision system for defect inspection in a cast extrusion manufacturing process

The cast extrusion manufacturing process is the initial step which enables the creation of the raw materials, such as clear polypropylene film, needed for the flexible packaging manufacturing process. The current methodology of controlling extrusion related defect occurrences is attempted by a combination of statistical sampling and human inspection. However, the defects are small in size and hard to visualise in a clear thin film 3 m in width moving at a speed of 50 m/min. This resulted in poor product quality and high return ratio from customers. To the best of our knowledge, there is no system available that can automatically and accurately detect such defects. This research investigates possible defect detection methodologies and has subsequently proposed a system that is capable of real time monitoring of defects on the cast extrusion manufacturing process.