Lockheed Martin Tactical Aircraft Systems - Ft. Worth, Texas
LMTAS was the first aerospace company to implement innovative aqueous cleaning technology for cleaning tubing and honeycomb core. Tubing is used in the aerospace industry for transferring pressurized oxygen within an aerospace vehicle. Honeycomb core is used in the Aerospace industry for producing bonded structural parts. Both applications require that the parts meet stringent cleanliness requirements. These requirements were previously met by using cold cleaning and/or vapor degreasing with chlorinated solvents. These solvents included 1,1,1-trichloroethene (TCA) and trichloroethylene (TCE). These chlorinated solvents are toxic, and TCA is an ozone depleting compound.
The use of chlorinated solvents posed a threat to the environment because they were commonly released into the air during cleaning operations and because the likelihood of a spill during their use was significant.
These solvents were successfully replaced with aqueous cleaning technology. Implementation of aqueous cleaning technology at LMTAS has eliminated approximately 360 tons of air emissions per year and has resulted in a cost savings of $490K per year. In addition to replacing chlorinated solvents with innovative aqueous cleaning technology, LMTAS has also explored the use of environmentally safe methods for quantifying surface contaminants on parts cleaned by various cleaning technologies. Traditionally, extraction with CFC-113 followed by gravimetric or FTIR analysis has been used for quantifying surface contaminants. The use of CFC-113 is undesirable due to its ozone depleting potential. LMTAS has demonstrated the usefulness of carbon dioxide coulometry for determining the amount of residue remaining on a surface after cleaning and has used this technique for comparing the cleaning effectiveness of various cleaning technologies.
Lockheed Martin Corporation received an EPA Stratospheric Ozone Protection Award for the adoption of aqueous cleaning technology for cleaning tubing.
In summary, replacements of chlorinated solvent cleaning operations with the aqueous cleaning operations offer the following benefits:
- A reduction in the toxicity of the cleaning compounds used.
- A reduction in the real and potential threat to the environment.
- A significant cost savings due to the lower disposal costs associated with the aqueous cleaning agents.
- The required cleanliness levels can be easily achieved with the aqueous cleaning (as verified by chemical analysis and mechanical testing). Novel analytical methods for cleanliness were demonstrated that use no hazardous solvents.
- The aqueous cleaning technology can be (and has been) readily transferred to other facilities and industry sectors.