A Graphical User Interface for IR-image-based Process Analysis : A tool for assessing root causes in paperboard variability

Abstract: Paperboard is produced in a large and complex process where many parameters can affect its quality. The common methods of analysing paperboard quality are through traversing point-like sensors that only measure a very small fraction of the produced paperboard. Holmen Iggesund Paperboard has installed an IR-camera that measures the entire paperboard web and is looking for a tool to assess paperboard quality variation based on these measurements. The purpose of this thesis work is to develop such a tool. This was done through developing a user-friendly computer application (app) IR-measurement Analysis (IRMA). The app is designed to help the process engineers of Iggesunds mill assess the paperboard variability, which strongly correlates with its quality. The quality improvements of paperboard mainly concern eliminating irregularities in thickness, grammage, and moisture. In IRMA, theuser can prepare data, perform statistical analyses, execute a frequency analysis through Fast Fourier Transform and then compare the frequency peaks with the frequencies of possible sources for periodic process variation, for example rolls. Correlating frequency peaks and roll frequencies can indicate issues with rolls and make process engineers at the mill aware of maintenance needs. IRMA have been tested at the mill and these tests have indicated that IRMA can be beneficial in the process engineer’s daily quality control measures. Furthermore, a manual has been written and the process engineers will be thoroughly educated in the use of IRMA.