What Dryer Fabric CFM Do I Need?

Dryer-fabric CFM is position-specific

One grade-wide CFM range cannot describe every dryer group. The correct permeability is part of a position-specific balance among sheet contact, pocket ventilation, moisture profile, fabric stability, contamination and seam performance.

Information needed for selection

• Paper grade, basis weight, width and operating speed
• Dryer group and single- or double-tier configuration
• Steam and condensate conditions, hood and pocket ventilation
• Sheet moisture entering and leaving the group, including cross-machine profile
• Existing fabric construction, permeability test standard, seam and failure mode

PAPTEX source sheets show different permeability configurations by dryer position. Those samples demonstrate why one number cannot be copied across the whole machine.

Validate the change

Compare equivalent grades and record sheet moisture, cross-machine profile, steam per ton, pocket conditions, sheet handling and deposits. Seam and body performance should be assessed with the same test method and as part of the actual operating result; do not apply a universal percentage tolerance without the design specification.

Submit dryer-group data for a permeability review.