Breathers & Bleeders
For release, the Breathers and Bleeders fabric includes a light layer of polytetrafluoroethylene (PTFE). It is a non-woven polyester or nylon fabric and is designed to allow airflow during the vacuum bagging process as well as bleed away excess resin in a composite part. It enables excellent adherence around a composite item when under vacuum or autoclave pressure.
At Airtech, breather fabric is available as standard rolls, slit widths, or cut shapes as per your specifications. Our Breathers and Bleeders fabrics allow the vacuum bagging process to continue smoothly and allow the resin to be bled out of composite parts, allowing great conformity throughout the bagging process.
The terms Breather and Bleeder are often used interchangeably. Functionally they are interchangeable, but the distinction is in use.Breather materials are used typically on top of a release film.
The purpose is to allow air under the bag to be evacuated during draw down, and continuously during cure. Any volatilespresent in the layup or generated during the cure can be removed as well.Most advanced composite materials in use currently are ‘net resin’ and do not require a Bleeder fabric.
However, there are legacy systems that do require Bleeder layers. Breather/Bleeders are available in various thickness and weights and material types. To fully explore the possibilities, review the Breathers and Bleeders section of the catalog and contact Airtech technical service engineers who are well versed in composite processes.