A RAPID HEATING PROCESS FOR OUT-OF-AUTOCLAVE CURING OF TOUGHENED EPOXY PREPREGS

摘要

Toughened epoxy prepregs are utilized in advanced composite structures on military aircraft. The conventional processing route employs autoclave curing under a pressure of 7 bars (100 psi) and long cycle times to achieve final properties. An out-of-autoclave advanced composite curing technology has been employed that uses a heat transfer fluid (HTF) to apply heat and modest pressure to the uncured epoxy prepreg during processing. The HTF enables precise control of the process temperature throughout the curing process. As this technology is based on rapid heat transfer and the ability to accurately control mold temperature, it offers potential savings on process time, energy, investment, and overall component manufacturing costs. Additionally, a differential vacuum technique has been applied to the laminates during the cure cycle that yields void-free laminates. This paper reviews the progression of the process development and the resulting panel and component qualities. Data showing process parameters, laminate properties, and cured components are presented.