Low Cost Fabrication Techniques for Propulsion Structures

Carbon fiber reinforced polymers have found wide use in aerospace structures, however currently used materials are costly and require extended cure times which greatly increases manufacturing cost and consequently part cost. Most aerospace and defense structural composites are manufactured using slow hand layup and autoclave curing processes which are labor intensive and costly. Cylindrical cross sections such as those use in pressure vessels and rocket motor cases utilize automated filament winding processes, however these methods are slow and labor intensive due to the placement of a single roving and the extended cure cycle required. Trimer proposes to implement pullwinding, a process which adds a circumferential winder to the pultrusion line such that the unidirectional fiber preform is overwrapped with a transverse reinforcement prior to entering the die. This process would allow the manufacture of 0/90 composite cylinders with high fiber volume fraction and low void content and uniform properties from batch to batch. Trimer will apply it’s patent pending thermoset resin which has a cost equivalence of vinyl ester yet a Tg > 700F and a cure time as little 120 sec. This resin will allow Timer to pultrude low cost propulsion structures which exceed the glass transition temperature requirements.