Paper Machine & Coaters, Reel Nip Relieving Systems

The Fitch Company has completed two major reel profiling projects consisting of nip relieving, bump-less transfer, and nip profiling, one on a paper machine and the other on an off-machine coater. Following is a description of the latest project.

The client was experiencing paper loss on every reel due to the high nip loading at turn-up due to the reel spool weight, the nip loading transients occurring during transfer from the primary to secondary arms, and at the end of the reel due to uneven winding tension. Our nip profiling system addressed each of these issues.

• The existing (Valmet) reel had built-in capability for nip relieving on turn-up but the system had never worked satisfactorily. The new controls installed as part of this project compensated for the nip loading caused by the reel spool weight over the entire range of spool position, from turn-up to transfer to the secondary arms, allowing the nip loading to be controlled entirely by the loading of the primary arm hooks. The new loading controls for the primary arm hooks allowed individual loading control for each primary arm hook.
• At transfer from the primary to secondary arms, the primary arm loading is decreased as the secondary arm loading is increased providing a totally bump-less transfer of nip loading from the primary to secondary arms.
• Since the effect of nip loading on reel winding tension varies with reel diameter, our nip-profiling program varies the nip loading as a function of diameter from a family of curves, which allows the client to provide custom winding tension compensation over a wide range of paper grades and weights.

Operator control is via an industrially rated touch-screen which provides adjustment and digital display of all controlled machine variables. Real-time graphical display and print-out of the of nip loading allows the operator to profile and record the nip loading throughout the reel building process.

Any of the three functions contained in our reel nip profiling system may be implemented separately, or in conjunction with any of the others as needed. We can provide a customized system for a specific reel nip problem designed to adapt to your existing or modified reel. Both installations have had returns on investment due to paper savings of much less than a year.

Contact us for more information.

More Specialty Applications

• Supercalender controls upgrades
• Process Control System Evaluation
  
• Winder controls
  
• Boiler & Steam applications
  
• Sheeter applications
  
• Roll wrapper applications
  
• Retrofit applications
  
• Drafting, design and documentation services
  
• Training services
  
• Paper machine and winder drive replacements
  

TOP