A large aircraft manufacturer was experiencing problems with corrosion
occurring on propellers for C-130 aircraft upon receipt from suppliers
and and when shipping spares to customers. The fourteen foot diameter
propellers are mainly constructed from composite materials, however
the hub contains sensitive control mechanisms that are susceptible
to corrosion.
Solution
Heritage Packaging designed and fabricated a two piece circular
cover from Cepac HD200 (a heavy duty barrier lamination from
Controlled Environment Packaging, Inc. of Buford GA). The cover
has 1/4" PE foam sealed at key locations on its interior
surface to cushion against protruding points. The cover's design
allows for "thru-bolting" the propeller to a mobile
dolly while maintaining an airtight seal. 16 unit Desipacks
are strategically placed inside the cover. The two pre-made
parts of the cover are then heat sealed together around the
outer perimeter. Then, utilizing a one way valve installed in
the cover by Heritage Packaging, a vacuum is drawn, the cover
is nitrogen flushed, and then a final vacuum is drawn. The goal
was to maintain consistent interior humidity readings below
40%.
Results
Humidity levels are monitored on a monthly basis using a digital
read-out thermo hygrometer. The covers have consistently maintained
humidity levels below 20%.
