CO2 Pellets General Information CO2 pellet cleaning is a form of abrasive cleaning. CO2 pellets are generated in a proprietary machine and used like any other blast media. Shortly after impact, the CO2 pellets sublimate, leaving only the soil for disposal and no residue on the surface. This is an effective process for removal of coatings, sealants, and adhesives. It will also remove grease, oil, paint, marine growth, and rust. It has been used on metallic and aircraft composite material substrates. CO2 pellets are used to clean rubber, metal alloys, fiberglass, brick, plastics, and ceramics. CO2 pellet cleaning should be considered wherever other abrasive blast processes are being used. The contamination to be removed must be accessible by the blast stream. Since CO2 pellet blasting is safe for many substrates, switching may eliminate the need for masking to protect adjacent areas. This is an effective process for removal of coatings, sealants, and adhesives. It will also remove grease, oil, and paint. It has been used on metallic and aircraft composite material substrates. Thin composites may be affected by blast pressures. Stripping paint from aircraft can approach 1 sq. ft./min after process optimization. This process has been combined with xenon flashlamp techniques to improve the paint stripping characteristics of either stand alone process. CO2 pellet cleaning should be considered wherever other abrasive blast processes are being used. A process has been developed by McDonnell-Douglas Aerospace, Cold Jet Inc., and Maxwell Laboratories, Inc., that combines CO2 pellets with a flashlamp. The flashlamp provides heat to destroy a coating's cohesive bonds; the pellets cool and clean the surface. The process has been successfully applied to aluminum and composite materials used in aircraft. Equipment noise levels are typically between 95 and 130 dB. Pellet size, velocity, and flow rate are variable. One application of the variations in velocity and flow rate is to use a lower powered nozzle for the initial blast to remove the majority of the contaminant and follow this by a higher powered nozzle to remove the remaining debris. Switching to CO2 pellet blasting may reduce the need for disassembly of parts relative to that required for hand wiping or other forms of abrasive cleaning. With CO2 pellet cleaning, there is no risk of grit entrapment. State Information | Glossary | Conversion Checklist | Comments Home | Process Advisor | Alternatives | Links | Search All SAGE material, Copyright© 1992, Research Triangle Institute Last Update: 18 March 1995 sage@rti.org http://clean.rti.org/alt.cfm?id=pe&cat=gi