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The Kadant Blog

Doctoring Suction Pressure Rolls on Tissue Machines

A suction pressure roll double doctor blade system is specially designed for dewatering suction pressure rolls in tissue making applications. The system is comprised of a specially designed holder in primary position that augments the natural vacuum created behind the blade tip to expel more water from the roll surface. The blade material is polyethylene which is safe to use on polyurethane roll covers. A secondary blade and lower wipe on the save-all pan removes any leftover water and prevents it from entering the ingoing nip. The save-all pan and drain system is custom designed and sized to effectively capture and take away the water.

Conventional doctor blades or wipes do not have the capacity to remove all the water in the roll, particularly with more open void areas in today’s rolls.

The addition of a suction pressure roll double doctor will provide noticeable benefits as the felt ages, becomes saturated, and accepts less water. The addition of a double doctor system on the suction pressure roll has significant impact on tissue quality, runnability, and energy consumption and can provide noticeable benefits such as:

  • Increased post pressure roll solids
  • Reduced hydraulic pressure points mean more uniform attachment of the sheet to the Yankee
  • More uniform moisture profile
  • Clean holes in roll to increase roll life

Learn more about Suction Pressure Roll Double Doctor Systems with the patented Airset B™ Doctor Blade Holder and an enhanced vacuum behind the blade that increases the water being drawn out of the roll surface.

  • Written by:
    Jerry Vandoros

    Jerry Vandoros

    Technical Director, Kadant Solutions Division

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