Tools/Epoxy/Fiberglass/Resin – West Systems – Breather Fabric

What is vacuum bagging?

Vacuum bagging is when a composite that is laid up and wet out by hand is then put under vacuum to compact the laminate and force out excess epoxy. Vacuum bagging has been a choice method of manufacturing and repairing composites for a long time.

Why vacuum bag a laminate?

The process of vacuum bagging allows for the ease of hand lamination while producing a part that has better properties because of its compaction. Vacuum bagging a laminate removes air voids and increases the fiber-to-epoxy ratio. All in all, it is a great process to improve your composite laminate.

The Role of Breather Fabric in Vacuum Bagging

The function of the breather fabric in a vacuum bagging layup is really two-fold. As vacuum pressure consolidates the laminate, the squeezed-out epoxy goes through the peel ply (and the release film if you are using it) and is absorbed by the breather fabric. Because of its open structure, air flows easily through breather fabric allowing the air to be evacuated from the consolidated laminate. Breather fabric is also referred to as a baby blanket.