Aside from holding vacuum, the material must be strong enough to withstand the temperatures and pressures of the curing cycle. It must stretch enough to fill deep corners and apply pressure to tight radius areas.
Another important feature of vacuum-bagging film is its ability to stick to the sealant tape.
Last but not least, the film must retain enough integrity after the cure cycle to enable removal from the tool in (hopefully) one piece!
Most vacuum-bagging film is made of nylon, and there are two kinds: Cast and Blown. Cast is better for higher temperatures (400-450F) but is generally "stiffer" (Yes. Harder to work with.) Blown film is more supple, easier to use, but doesn't take the higher-end heat as well as the cast film will. However, most cure cycles in use today are well within the capabilities of blown film. |
