The ABB Web Imaging System (WIS) was installed on BM8 in 2006 and was updated in 2012. The first version was installed on BM7 in 2008 and was updated in 2015.
Through an updated camera model and specially designed algorithms, every square millimeter of the paperboard web is now inspected at speeds of up to 800 meters a minute. The most recent upgrades that were performed also allow for the detection of shearing defects in the paperboard.
“Shearing defects are tiny millimeter-sized shifts in the paperboard’s structure, which, in the worst-case scenario, can lead to cracks when the paperboard is folded into packaging. The cracks can then cause leakage when the cartons are filled with liquid,” says Björn Wikström, Maintenance Technician at Stora Enso in Skoghall.
Correcting shearing defects is time-consuming and can result in major production losses. Using camera beams at BM8 and now at BM7, Stora Enso can correct the process in 2–3 minutes, thanks to continuously updated information that reaches the operator stations within seconds.
“Shearing arises very sporadically. The cameras have to be able to detect tens of thousands of defects in just a few minutes. At the same time, the defects have to be analyzed and visualized so that they can be rectified quickly. The operator now has a tool at his or her disposal that visualizes the shearing defects of various sizes as color-coded markings on a chart,” says Håkan Österholm, product manager at ABB.
“This is a very user-friendly tool that benefits everyone, from machine operators to winder and re-reeler operators, and naturally also our quality and development engineers. We have designed the interface so that it suits the unique needs of all user groups,” adds Wikström.