A method for precision cleaning of aerospace components is needed that does not use hazardous or environmentally harmful commodities. Historically, precision cleaning methods have utilized solvents that have contributed to the depletion of the ozone layer or had high potential for contributing to global warming. Solvent cleaning produces large waste streams, and some solvents may be phased out in the future due to the environmental concerns.
This innovation allows for component cleaning to be accomplished using a low-pressure plasma cleaning system combined with breathing or compressed air as the feed gas. Traditional low-pressure plasma cleaning uses specifically tailored and highly pure gases (e.g., hydrogen, oxygen, argon, nitrogen) to perform the cleaning that are more costly and have inherent flammability concerns. Plasma cleaning with air has the following advantages over other precision cleaning methods: produces essentially no hazardous waste stream, no drying time, renewable low-cost consumable (air), and simple operation. Plasma cleaning with air has demonstrated the ability to meet the strictest level of nonvolatile residue (NVR) cleanliness (10mg/m2) in Kennedy Space Center's Specification for Surface Cleanliness of Ground Support Equipment Fluid Systems, KSC-C-123J.