A material for large parts, without an autoclave

Cycom 5320 is a toughened epoxy resin prepreg system from Cytec Engineered Materials, Woodland Park, NJ. It is intended for out-of-autoclave (OOA) manufacturing yet provides the performance of an autoclaved material with the benefit of lower processing costs and manufacturing flexibility. The material allows designing large primary structures, without the costs and size limitations of an autoclave. Only a properly sized oven is needed.

(1) After an initial 200F at 8 hr, a part’s degree of cure is 52%. This allows for handling and free-standing post cure. (2) A combined cure and post cure on the tool may be performed by ramping to 250F, holding for one hour, ramping to 350F and holding for two hours.

Low temperature curing makes the material well suited for many structural and aerospace applications. Low-cost tooling and OOA curing offers the advantage of using one material for prototype and high-rate production.

Cycom 5320 offers the mechanical performance equivalent to 350F autoclave-cured, toughened epoxy prepreg systems. The material gives users flexibility to vary the cure cycle from 200F for 8hr to 250F for 2hr (followed by a 350F two-hour post cure). This flexibility provides a wide processing window to provide maximized mechanical properties.

Cytec engineers built the wing skin demonstration panel for Boeing using CYCOM 5320 and are putting it in an oven. The panel it was on display at JEC Composites show in March. Public release of the hat stiffened skin was covered by Air Force case 88ABW-2008-0466 and by DARPA as DISTAR 12455.

The company lists these additional features and benefits for the material:

• Developed for primary structures
• Excellent hot and wet properties
• Low void content
• Suitable for complex parts
• Low cost tooling
• Flexible cure cycles
• Mechanical properties equivalent to standard 350F or 177C, autoclave-cured epoxy after freestanding post cure