Comparing 20 CFM to denier

Compiled by Juli Case

We’re making a filter bag for a local manufacturing plant and are told that the fabric needs to be 20 CFM. How does that compare to denier?

It doesn’t, because they measure two different things. Denier is a weight-per-unit-length measurement and is used to describe the size of yarns or fibers. CFM is an abbreviation used to describe the air flow of fabric and stands for cubic feet per minute. It refers to the number of cubic feet of air that will pass through one square foot of fabric in one minute at a standard pressure drop of half an inch. This piece of information is referenced in ASTM D737, Test Method for Air Permeability of Textile Fabrics. Any supplier of filtration fabrics will be familiar with CFM and able to inform you of their materials with that level of air flow.

Juli Case is IFAI‘s information and technical services manager.