Aerospace Composite Stringers and Stiffners
Industry
Aerospace Composites
Application
Release coating of silicone bladders with heat shrink tubing, replacing hand wrapping process
Problem
Long composite tubular structures, between 20 -40' in length, require an inflatable silicone bladder on the parts inside mold line. Bladder had to be wrapped by hand with ETFE release film before carbon fiber prepreg layup process. Hand wrapping step was labor intensive, and resulted in inconsistent application of release film down length of part, which included film overlaps and adhesive tape strips to secure film, all contributing to undesiriable thickness build up between tool and composite part. Inconsistent surface of release film can lead to film being pinched in cured composite, creating difficulty when trying to remove from the inside diameter of cured part.
Dunstone Solution
LST-ET Heat Shrink Tubing
Implementaion
Dunstone LST Heat Shrink Tubing used in the bladder preparation process allows the customer to prepare more parts in less time in order to incorporate them into the larger fuselage section prior to autoclave cycle. LST-ET tubing shrinks quickly, and without wrinkles. Compared to other heat shrink release film tubes, Dunstone LST-ET has a very consistent thickness which give it uniform shrink % throughout.