Dryer Fabric Air Permeability: How to Use the Value in a Paper-Machine Inquiry

Air permeability is frequently requested in dryer-fabric inquiries, but the value is meaningful only when its test condition and machine context are understood. It should guide a technical discussion, not replace one.

Why one number is not a complete specification

Air movement, contact behavior, sheet support, and cleanliness are affected by fabric construction, position, paper grade, the dryer group, and the condition of the running fabric. Two fabrics with a similar quoted value may behave differently when their structures and service conditions differ.

What to provide with the requested range

Include the existing fabric specification if known, its running position, paper grade, speed, moisture or drying observations, and the reason for replacement. Describe whether the concern is reduced drying response, marks, contamination, unstable travel, or a planned optimization. Confirm the test basis when comparing values from different suppliers.

Use a controlled review before changing construction

Ask for the proposed construction and the assumptions behind the recommendation. Changes should be reviewed against installation dimensions, seam requirements, roll condition, and the operating target. Browse the available fabric constructions and send the complete data through our inquiry form for a position-specific review.

Summary

Air permeability is useful when it is connected to the entire operating picture. A documented comparison is safer than choosing solely by a catalogue value.