Seal Bond Removal

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Advanced Materials OBJECTIVE: To develop a pulse hand-held laser to remove nitrile-phenolic resin from aircraft surfaces. DESCRIPTION: Hand-held laser technology developed for aircraft skin paint removal has not been tailored for nitrile-phenolic film adhesive removal, partly because the nitrile-phenolic film adhesive is a niche application it falls between the realm of structural bonding and sealing. The F-16 makes extensive use of nitrile-phenolic heat cured adhesives. Breaking the adhesive bonds requires cryogenic treatment to induce brittleness and leaves a significant amount of residue on parts. At present this residue is removed using 100% methyl-ethyl-ketone (MEK) and non-metallic scrapers. This method is extremely time consuming, but sanding and similar methods are not appropriate because many of the bonded components are fracture critical parts (surface must not have scratching or gouging to minimize the risk towards developing cracks). A method that would quickly and fully remove the residue without damaging the parts would represent a significant time savings and would remove 100% MEK from the work environment. To fulfill the objective of removing the residue after the cryogenic treatment, new methods are being researched and tested. PACAF depot contractor Korean Airlines uses a locally made portable water jet for removal. However, as the water jet is locally made, it is not available for Hill AFB or USAFE. This approach also generates a need to remediate the wastewater stream. Another method that has been tested but not approved is a hand-held pulse laser system. The laser system has proven to remove the adhesive, but testing has not been done with regards to structural fatigue or environmental concerns regarding decomposition. PHASE I: FEASABILITY DOCUMENTATION. For this Direct-to-Phase II topic, applicants must demonstrate the feasibility to remove Nitrile-Phenolic heat cured adhesives (FMS-3014) in an aircraft maintenance environment. PHASE II: Develop a working prototype to remove nitrile-phenolic adhesives from F-16 aircraft components. A complete successful nitrile-phenolic adhesive removal hand held laser prototype would be demonstrated through tests as recommended by the F-16 System Program Office. PHASE III DUAL USE APPLICATIONS: Refine hardware and software to increase accuracy and reliability. Achieve production-ready state for marketing to the Air Force, other related federal agencies, and private industry. REFERENCES: 1. Matthew Campbell, Laser System for Supplemental Coatings Removal Test Plan, ADB379774; 2. Ms. Shanna Denny, Mr. Juan Valencia, and Mr. Mark Phillippi, Mr. Jim Arthur, Optimization Of Aircraft Laser Coating Removal Processes Final Report, ADB397147; 3. Ms. Shanna Denny and Mr. James Arthur Jr., Optimization Of Aircraft Laser Coating Removal Processes Test Plan, ADB387150; 4. Shanna Denny/Matthew Campbell, Develop and Demonstrate Hand-Held Aircraft Laser Coating Removal in a Production Environment Final Report, ADB393963; 5. Mongelli, Gerard, Portable Handheld Laser Small Area Supplemental Coatings Removal System Final Report, ADA606886. KEYWORDS: Bond seal removal; Nitrile-Phenolic