Roll-to-roll web handling for membrane inspection

This paper describes our ongoing development of a roll-to-roll (R2R) web handling system for thin and flexible membrane inspection using machine vision. Leakproof membrane is essential in many industries, e.g. food packaging and medical applications. Our primary objective is to achieve full quality control check for through-hole defects in membrane, and mark them if any. To achieve 100% inspection of the 400 mm wide and 1 km long web, a laterally movable camera stage is coordinated with web handling subsystem that uses basic trapezoidal motion control for repositioning the web so as to overcome the small area of inspection of the two line scan cameras mounted on stage, each with 80 mm field of view. As there is no open-source publication on web handling for R2R membrane inspection, we hope our methodology and findings through this work would be useful to other related research. Besides detailing the system design and setup, this paper also discusses the challenges faced, highlights the system performance, its shortcomings and areas of improvement.