For Iggesund, video analysis means quality, production benefits, Solutions!, Online Exclusives, August 2004

"When a board machine stops due to a web break we have only one priority: to get things up and running again as soon as possible. A camera system provides support in the decision-making process, making it easy for the operator to pinpoint the cause of the break and avoid the same problem arising again."

"Reducing the number of web breaks is important for both quality consistency and production. Modern camera systems are a key tool in the hunt for the causes of web breaks," explain Daniel Thor and Gunnar Hållén of Iggesund Paperboard.

That is how Daniel Thor, production manager for the KM1 board machine at Iggesunds Bruk, Sweden, describes how Iggesund Paperboard uses camera systems. Iggesund Paperboard is part of the Swedish forest products group Holmen.

A board or paper machine should be in operation as much as possible. Every stoppage costs money in the form of lost production and quality variations when the machine is restarted. At KM1 the detection of web breaks and their causes has intensified following the installation of a digital camera system that records onto hard disk. Twenty-two cameras located along the length of the board machine record events within the most recent four-minute time period, enabling the operator to search for deviations and their causes.

"The system of cameras is nothing new, but the digital technology and hard disk recording have made them much more useful than before. It’s much faster to work with them than with the older systems," explains Gunnar Hållén, process engineer at the mill.

When a web break occurs, mill technicians leap into action with the aim of restarting production as soon as possible. By using the camera system as an analysis tool the cause of the break can be quickly determined and there is less risk of trying to restart the machine without first having fixed whatever caused the stoppage.

"Web breaks mean a drop in production but they also cause quality variations in what is produced," Thor adds. "Reducing the number of web breaks is one of the most important measures we can take to increase quality consistency. That’s why we prioritize them at all of our production follow-up meetings."

Within a short period of time, the use of the camera system at KM1 has led to a more reliable classification of the causes of web breaks. It has also caused a noticeable reduction in the number of breaks and a resulting increase in output. Recently the machine broke a monthly production record that had stood since 1991.

"Since high and consistent quality is one of Invercote’s most important selling points, we will further develop this approach," Thor adds. "Our goal is to be a world leader in web break avoidance."

The camera system records breaks in the web while a complementary system for the detection of holes and surface defects starts recording when such a flaw occurs. Using both these systems in conjunction is important for increasing knowledge about what is happening inside the board machine.

Being able to determine the causes of these problems not only improves production volumes and quality consistency; the system also provides more reliable indications of where to focus maintenance for maximum effect, which makes it possible to reduce maintenance costs.

"During the past month we were able to significantly reduce the number of web breaks,” Thor says. "Our investments in hardware and knowledge expansion will be repaid in greater production volumes and improved quality. And the knowledge we gain about what’s happening inside the machine is crucial to all our R&D work."

Iggesund Paperboard uses camera systems as analysis tools at all its board machines in both Iggesund and Workington.