TAPPI TIP 0404-57 PDF

Poor cross-machine direction (CD) moisture profiles result in non-uniform paper end-use properties, converting problems, and poor runnability in the form of wrinkles and breaks. Fiber costs (such as heavy edges) and energy consumption can be higher than when moisture is more uniform.

Final moisture profiles reflect complex interactions between headbox, forming, pressing, drying, and gauging and control systems. Many CD moisture profile problems originate in the press section, although they can also be caused by dry weight profile, forming, or drying problems.

This TIP discusses steps to take and tools available to troubleshoot CD profile problems. Steps to identify the source of the problem include:
1. Evaluate information from the machine gauging and CD control system.
2. Determine where poor profile originates.
3. Pinpoint the cause to get an effective solution.
Additional Technical Information Papers provide more information on troubleshooting issues in the forming (TIP 0502-14 "Forming section monitoring"), pressing (TIP 0404-19 "Press section monitoring"), (TIP #0404-46 "Techniques for nip impressions"), (TIP #0404-65 "Chemical cleaning guide for press fabrics"), (TIP #0404-58 "Steam Showers in the Forming and Press Section") and drying (TIP 0404-33 "Dryer section performance monitoring"), (TIP #0404-39 "Dryer surface temperature measurement") sections.