Computer-Aided Wet End Chemistry Diagnostics, 1991 Papermakers Conference Proceedings

In paper manufacture uncontrolled fluctuations in the wet end chemistry may cause serious problems both in the process and in the paper quality. The reasons for such fluctuations are not always easy to identify.

Specialists at the Finnish Pulp and Paper Research Institute have developed a computer based diagnostic system for analyzing different measured values obtained from the wet end in paper machines. Using WEDGE (Wet End Diagnostics GEnius) a thorough process analysis can be conducted without detailed knowledge of the mathematical background.

Measured values are continuously fed to the computer for the analysis required. The data is analyzed using different methods for statistical analysis. Spectral methods, statistical process control (SPC) or multichannel autoregressive analysis (MAR) can be used for processing the data. In this manner fluctuations can be followed backwards in the system in order to find the origin of the disturbances.

Experience from mill trials show very promising results.