Thickness quality control and diagnosis system for tinplate rolling mills

The draw wall ironed (DWI) tinplate market clearly trends to demand a reduction in thickness, which implies stricter tolerance levels as small variations could result in problems in the manufacturing process and therefore customer's dissatisfaction in a highly competitive market. This paper describes a series of methods to detect thickness defects in DWI tinplate. In addition, these methods provide information to identify the origin of the defects, allowing fast corrections and therefore improving mill performance. In our approach an adapted thickness signal is spatially sampled from the input stages of the mill's last X-ray gauge.