Precision aqueous cleaner for RSRM
Chlorinated solvents such as freon and 1,1,1 trichloroethane (TCA) are both environmental and physiological hazards which deplete stratospheric ozone. These chemicals are the primary degreasing solvents (vapor, vat, and hand operations) in redesigned solid rocket motor (RSRM) manufacturing. Due to the mandates of the Clean Air Act, substitutes must be identified for RSRM cleaning processes. The initial phase of laboratory testing identified candidate cleaners to replace 1,1,1 trichloroethane for cleaning, potentially reducing annual TCA consumption by 800,000 lbs. This paper describes RSRM testing which elucidated the effects of several interdependent variable including: definition of surface cleanliness criteria, validation of cleaning power of new candidates, the effect of immersion cleaning versus spray cleaning on cleaning, any effect of the cleaner and/or inhibitor upon bondline aging, and compatibility of the cleaners with nonmetallic tooling and processing materials.