In 1994, traditional depainting processes generated approximately 2.5 million pounds, or 20 percent, of all reportable waste produced by U.S. Department of Defense (DoD) operations. There was a need to identify less wasteful depainting methods. The objective of this project was to demonstrate that the FLASHJET® coating removal technology greatly reduces the volume of hazardous waste produced and reduces worker exposure to hazardous materials.

Technology Description

The FLASHJET® process combines a xenon-flashlamp with low pressure carbon dioxide (dry ice) pellet blasting. The xenon-flashlamp ablates the coating from the substrate and the dry ice pellets cool and clean the substrate and sweep the coating into an effluent capture system. The effluent capture system vacuums the by-product dust through a series of air pollution control equipment including High Efficiency Particulate Air (HEPA) filters. These filters leave the air clean enough for venting to the atmosphere. The automated system does not require direct worker involvement so safety and health risks are minimized.

Demonstration Results

The FLASHJET® process was evaluated on rotary wing and ground/fighting vehicle applications, including one operational SH-60 Seahawk helicopter, six off-aircraft components from a CH-53 helicopter, and one M113 Armored Personnel Carrier. Results showed that the FLASHJET® process could effectively remove greater than 90 percent of the exterior topcoat without any damage to the underlying substrates. A high cycle fatigue testing program was also conducted to determine the potential fatigue effects on thin Aluminum substrates commonly found on rotary wing aircraft. Results from this testing program show that the pulsed light energy does not have any effect on the thin Aluminum substrates.

Implementation Issues

The FLASHJET® process generates less waste than other coating removal processes, which results in lower waste disposal costs. It also requires fewer operators, thus lowering the labor costs associated with depainting activities. Together, these factors significantly lower the life cycle cost of the FLASHJET® process over other traditional coating removal processes.

The FLASHJET® stripping head cannot access tight corners due to its size; therefore, a secondary coating removal process may be needed. The process is best utilized on long, flat external surfaces. (Project Completed - 2003)