Combination of CD profile measurements with process data

Profile measurements are typically monitored visually with 2D-profile maps. 2D-profile maps are usually designed for viewing purposes and it is difficult to extract useful detailed information from those. Process measurements cannot be studied together with profile maps and therefore it is not possible to perform root-cause analysis to find origin of profile quality disruptions. There is a need for flexible profile data handling system with an online connection to process data.

With a new system profile data can be handled similarly like any other process measurement. The user can freely select any time interval for study and clear outlier data points from the data set. The analysis can be focused to certain time periods, i.e. grade runs or jumbo rolls etc. Profile variations can be characterized with calculated indices which pinpoint problems in the profile measurements. The profile variation indices can be compared with process measurements to find those process changes that cause changes in CD profiles. This methodology ensures uniform and high quality CD profile of produced paper.