Monitoring & Control for Metered Size Press Optimization, 1996 Metered Size Press Forum Proceedings

Sanford I. Shapiro

Honeywell Inc.

The growing number of “metered size press” installations of all kinds is proof of the desire by the paper and paperboard to increase product quality and machine runnability in a cost effective manner. To achieve these goals, the basestock, sizing/coating material, application and drying must be optimized. Basestock quality must be controlled tightly, from stock preparation through forming, pressing, and the pre-size dryers. On-line sensors make possible manual and closed-loop control of key variables. Sheet moisture going into the size press must be uniform, with minimum streaks, to minimize variations in pickup. Cross-direction automatic controls can reduce the major streaks, but manual process tuning is often necessary to minimize transient streaks. The sizing or coating slurry applied to the web must be continuously controlled for pH, temperature, and percent solids. On-line sensors for pickup weight are used for quality monitoring and adjustment. Camera-based on-line 100% inspection can detect physical defects and immediately show a picture of each defect to the operator for corrective action, and for quality record long-term archiving. Use of the proper monitoring and controls will provide operators, technicians, and management with a cost-effective way to optimize operations and improve competitive position.