Improving product quality in pulp mill using statistical processcontrol (SPC)

摘要

The paper describes the application of statistical process control(SPC) to enhance product quality at Slave Lake Pulp Corporation,Alberta. The Slave Lake Pulp Corporation started its greenfield bleachedchemi-thermo-mechanical pulp (BCTMP) mill in December 1990. Criticalpulp quality parameters, such as freeness and brightness, are entered toa computerized mill-wide information system (MOPS) by operators. TheMOPS system and the SPC package was developed and supplied byMoDo-Chemetics, Vancouver. Feedback from the SPC alerts the operators to“out-of-control” data points. Corrective action is takenimmediately to identify the causes. The SPC control charts have improvedoperator understanding of the process, and reduced the response timerequired to return the process to target conditions. The overall resultof using SPC at Slave Lake Pulp Corporation has improved in productuniformity of brightness and freeness by 60% and 26%, respectively