Portable Handheld Laser Small Area Supplemental Coatings Removal System

Abstract

Abstract : The traditional coating removal methods employed throughout the Department of Defense (DoD) involve hazardous chemical or abrasive blast media. These conventional methods result in major waste streams consisting of toxic chemicals and spent blast materials. The chemicals typically used in this process are high in volatile organic compounds (VOC) and hazardous air pollutants (HAP), both of which are targeted for reduction/elimination by environmental regulations. Coatings removal operations that use abrasive blast media instead of chemical methods result in large quantities of solid hazardous waste, which is subject to high disposal costs and scrutiny under environmental regulations. Because of these environmental concerns, all branches of DoD involved in coatings removal operations are concerned with identifying alternative methodologies focused primarily towards the elimination or reduction of chemical paint strippers (such as methylene chloride and methyl ethyl ketone), dry media blasting (using either plastic media or wheat starch), and hand sanding. As a result, portable hand held laser systems have been identified as a technology with the potential to supplement existing coating removal operations. Laser coating removal is a nonintrusive, non-kinetic energy process that can be applied to a variety of substrates, including composites, glass, metal, and plastics. High-level absorption of energy occurs at the surface of a coating material resulting in the decomposition and removal of the coating. The applied energy is mostly absorbed and utilized in coating decomposition (i.e., instant evaporation, which carries away most of the radiation energy); therefore, the substrate experiences only a minimal increase in temperature. The only waste generated is the removed coating. The use of laser energy to strip coatings is a relatively new technology developed primarily for use in the aerospace industry. regulations.